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Commit 604326b4 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Alexei Starovoitov
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bpf, sockmap: convert to generic sk_msg interface 

Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.

This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.

Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.

The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.

Joint work with John.
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 1243a51f
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Inline Side-by-side
Showing with 2925 additions and 2860 deletions
include/linux/bpf.h
View file @ 604326b4
......@@ -737,33 +737,18 @@ static inline void bpf_map_offload_map_free(struct bpf_map *map)
}
#endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */
#if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_INET)
struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key);
struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key);
int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type);
int sockmap_get_from_fd(const union bpf_attr *attr, int type,
struct bpf_prog *prog);
#if defined(CONFIG_BPF_STREAM_PARSER)
int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, u32 which);
int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog);
#else
static inline struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
{
return NULL;
}
static inline struct sock *__sock_hash_lookup_elem(struct bpf_map *map,
void *key)
{
return NULL;
}
static inline int sock_map_prog(struct bpf_map *map,
struct bpf_prog *prog,
u32 type)
static inline int sock_map_prog_update(struct bpf_map *map,
struct bpf_prog *prog, u32 which)
{
return -EOPNOTSUPP;
}
static inline int sockmap_get_from_fd(const union bpf_attr *attr, int type,
struct bpf_prog *prog)
static inline int sock_map_get_from_fd(const union bpf_attr *attr,
struct bpf_prog *prog)
{
return -EINVAL;
}
......@@ -839,6 +824,10 @@ extern const struct bpf_func_proto bpf_get_stack_proto;
extern const struct bpf_func_proto bpf_sock_map_update_proto;
extern const struct bpf_func_proto bpf_sock_hash_update_proto;
extern const struct bpf_func_proto bpf_get_current_cgroup_id_proto;
extern const struct bpf_func_proto bpf_msg_redirect_hash_proto;
extern const struct bpf_func_proto bpf_msg_redirect_map_proto;
extern const struct bpf_func_proto bpf_sk_redirect_hash_proto;
extern const struct bpf_func_proto bpf_sk_redirect_map_proto;
extern const struct bpf_func_proto bpf_get_local_storage_proto;
......
include/linux/bpf_types.h
View file @ 604326b4
......@@ -57,7 +57,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_ARRAY_OF_MAPS, array_of_maps_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_HASH_OF_MAPS, htab_of_maps_map_ops)
#ifdef CONFIG_NET
BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops)
#if defined(CONFIG_STREAM_PARSER) && defined(CONFIG_INET)
#if defined(CONFIG_BPF_STREAM_PARSER)
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKHASH, sock_hash_ops)
#endif
......
include/linux/filter.h
View file @ 604326b4
......@@ -520,24 +520,6 @@ struct bpf_skb_data_end {
void *data_end;
};
struct sk_msg_buff {
void *data;
void *data_end;
__u32 apply_bytes;
__u32 cork_bytes;
int sg_copybreak;
int sg_start;
int sg_curr;
int sg_end;
struct scatterlist sg_data[MAX_SKB_FRAGS];
bool sg_copy[MAX_SKB_FRAGS];
__u32 flags;
struct sock *sk_redir;
struct sock *sk;
struct sk_buff *skb;
struct list_head list;
};
struct bpf_redirect_info {
u32 ifindex;
u32 flags;
......@@ -833,9 +815,6 @@ void xdp_do_flush_map(void);
void bpf_warn_invalid_xdp_action(u32 act);
struct sock *do_sk_redirect_map(struct sk_buff *skb);
struct sock *do_msg_redirect_map(struct sk_msg_buff *md);
#ifdef CONFIG_INET
struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
struct bpf_prog *prog, struct sk_buff *skb,
......
include/linux/skmsg.h 0 → 100644
View file @ 604326b4
/* SPDX-License-Identifier: GPL-2.0 */
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
#ifndef _LINUX_SKMSG_H
#define _LINUX_SKMSG_H
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/scatterlist.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp.h>
#include <net/strparser.h>
#define MAX_MSG_FRAGS MAX_SKB_FRAGS
enum __sk_action {
__SK_DROP = 0,
__SK_PASS,
__SK_REDIRECT,
__SK_NONE,
};
struct sk_msg_sg {
u32 start;
u32 curr;
u32 end;
u32 size;
u32 copybreak;
bool copy[MAX_MSG_FRAGS];
struct scatterlist data[MAX_MSG_FRAGS];
};
struct sk_msg {
struct sk_msg_sg sg;
void *data;
void *data_end;
u32 apply_bytes;
u32 cork_bytes;
u32 flags;
struct sk_buff *skb;
struct sock *sk_redir;
struct sock *sk;
struct list_head list;
};
struct sk_psock_progs {
struct bpf_prog *msg_parser;
struct bpf_prog *skb_parser;
struct bpf_prog *skb_verdict;
};
enum sk_psock_state_bits {
SK_PSOCK_TX_ENABLED,
};
struct sk_psock_link {
struct list_head list;
struct bpf_map *map;
void *link_raw;
};
struct sk_psock_parser {
struct strparser strp;
bool enabled;
void (*saved_data_ready)(struct sock *sk);
};
struct sk_psock_work_state {
struct sk_buff *skb;
u32 len;
u32 off;
};
struct sk_psock {
struct sock *sk;
struct sock *sk_redir;
u32 apply_bytes;
u32 cork_bytes;
u32 eval;
struct sk_msg *cork;
struct sk_psock_progs progs;
struct sk_psock_parser parser;
struct sk_buff_head ingress_skb;
struct list_head ingress_msg;
unsigned long state;
struct list_head link;
spinlock_t link_lock;
refcount_t refcnt;
void (*saved_unhash)(struct sock *sk);
void (*saved_close)(struct sock *sk, long timeout);
void (*saved_write_space)(struct sock *sk);
struct proto *sk_proto;
struct sk_psock_work_state work_state;
struct work_struct work;
union {
struct rcu_head rcu;
struct work_struct gc;
};
};
int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
int elem_first_coalesce);
void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len);
int sk_msg_free(struct sock *sk, struct sk_msg *msg);
int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg);
void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes);
void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
u32 bytes);
void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes);
int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes);
int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes);
static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
{
WARN_ON(i == msg->sg.end && bytes);
}
static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes)
{
if (psock->apply_bytes) {
if (psock->apply_bytes < bytes)
psock->apply_bytes = 0;
else
psock->apply_bytes -= bytes;
}
}
#define sk_msg_iter_var_prev(var) \
do { \
if (var == 0) \
var = MAX_MSG_FRAGS - 1; \
else \
var--; \
} while (0)
#define sk_msg_iter_var_next(var) \
do { \
var++; \
if (var == MAX_MSG_FRAGS) \
var = 0; \
} while (0)
#define sk_msg_iter_prev(msg, which) \
sk_msg_iter_var_prev(msg->sg.which)
#define sk_msg_iter_next(msg, which) \
sk_msg_iter_var_next(msg->sg.which)
static inline void sk_msg_clear_meta(struct sk_msg *msg)
{
memset(&msg->sg, 0, offsetofend(struct sk_msg_sg, copy));
}
static inline void sk_msg_init(struct sk_msg *msg)
{
memset(msg, 0, sizeof(*msg));
sg_init_marker(msg->sg.data, ARRAY_SIZE(msg->sg.data));
}
static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
int which, u32 size)
{
dst->sg.data[which] = src->sg.data[which];
dst->sg.data[which].length = size;
src->sg.data[which].length -= size;
src->sg.data[which].offset += size;
}
static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
{
return msg->sg.end >= msg->sg.start ?
msg->sg.end - msg->sg.start :
msg->sg.end + (MAX_MSG_FRAGS - msg->sg.start);
}
static inline bool sk_msg_full(const struct sk_msg *msg)
{
return (msg->sg.end == msg->sg.start) && msg->sg.size;
}
static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which)
{
return &msg->sg.data[which];
}
static inline struct page *sk_msg_page(struct sk_msg *msg, int which)
{
return sg_page(sk_msg_elem(msg, which));
}
static inline bool sk_msg_to_ingress(const struct sk_msg *msg)
{
return msg->flags & BPF_F_INGRESS;
}
static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
{
struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
if (msg->sg.copy[msg->sg.start]) {
msg->data = NULL;
msg->data_end = NULL;
} else {
msg->data = sg_virt(sge);
msg->data_end = msg->data + sge->length;
}
}
static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
u32 len, u32 offset)
{
struct scatterlist *sge;
get_page(page);
sge = sk_msg_elem(msg, msg->sg.end);
sg_set_page(sge, page, len, offset);
sg_unmark_end(sge);
msg->sg.copy[msg->sg.end] = true;
msg->sg.size += len;
sk_msg_iter_next(msg, end);
}
static inline struct sk_psock *sk_psock(const struct sock *sk)
{
return rcu_dereference_sk_user_data(sk);
}
static inline bool sk_has_psock(struct sock *sk)
{
return sk_psock(sk) != NULL && sk->sk_prot->recvmsg == tcp_bpf_recvmsg;
}
static inline void sk_psock_queue_msg(struct sk_psock *psock,
struct sk_msg *msg)
{
list_add_tail(&msg->list, &psock->ingress_msg);
}
static inline void sk_psock_report_error(struct sk_psock *psock, int err)
{
struct sock *sk = psock->sk;
sk->sk_err = err;
sk->sk_error_report(sk);
}
struct sk_psock *sk_psock_init(struct sock *sk, int node);
int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg);
static inline struct sk_psock_link *sk_psock_init_link(void)
{
return kzalloc(sizeof(struct sk_psock_link),
GFP_ATOMIC | __GFP_NOWARN);
}
static inline void sk_psock_free_link(struct sk_psock_link *link)
{
kfree(link);
}
struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock);
#if defined(CONFIG_BPF_STREAM_PARSER)
void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link);
#else
static inline void sk_psock_unlink(struct sock *sk,
struct sk_psock_link *link)
{
}
#endif
void __sk_psock_purge_ingress_msg(struct sk_psock *psock);
static inline void sk_psock_cork_free(struct sk_psock *psock)
{
if (psock->cork) {
sk_msg_free(psock->sk, psock->cork);
kfree(psock->cork);
psock->cork = NULL;
}
}
static inline void sk_psock_update_proto(struct sock *sk,
struct sk_psock *psock,
struct proto *ops)
{
psock->saved_unhash = sk->sk_prot->unhash;
psock->saved_close = sk->sk_prot->close;
psock->saved_write_space = sk->sk_write_space;
psock->sk_proto = sk->sk_prot;
sk->sk_prot = ops;
}
static inline void sk_psock_restore_proto(struct sock *sk,
struct sk_psock *psock)
{
if (psock->sk_proto) {
sk->sk_prot = psock->sk_proto;
psock->sk_proto = NULL;
}
}
static inline void sk_psock_set_state(struct sk_psock *psock,
enum sk_psock_state_bits bit)
{
set_bit(bit, &psock->state);
}
static inline void sk_psock_clear_state(struct sk_psock *psock,
enum sk_psock_state_bits bit)
{
clear_bit(bit, &psock->state);
}
static inline bool sk_psock_test_state(const struct sk_psock *psock,
enum sk_psock_state_bits bit)
{
return test_bit(bit, &psock->state);
}
static inline struct sk_psock *sk_psock_get(struct sock *sk)
{
struct sk_psock *psock;
rcu_read_lock();
psock = sk_psock(sk);
if (psock && !refcount_inc_not_zero(&psock->refcnt))
psock = NULL;
rcu_read_unlock();
return psock;
}
void sk_psock_stop(struct sock *sk, struct sk_psock *psock);
void sk_psock_destroy(struct rcu_head *rcu);
void sk_psock_drop(struct sock *sk, struct sk_psock *psock);
static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock)
{
if (refcount_dec_and_test(&psock->refcnt))
sk_psock_drop(sk, psock);
}
static inline void psock_set_prog(struct bpf_prog **pprog,
struct bpf_prog *prog)
{
prog = xchg(pprog, prog);
if (prog)
bpf_prog_put(prog);
}
static inline void psock_progs_drop(struct sk_psock_progs *progs)
{
psock_set_prog(&progs->msg_parser, NULL);
psock_set_prog(&progs->skb_parser, NULL);
psock_set_prog(&progs->skb_verdict, NULL);
}
#endif /* _LINUX_SKMSG_H */
include/net/tcp.h
View file @ 604326b4
......@@ -858,6 +858,21 @@ static inline void bpf_compute_data_end_sk_skb(struct sk_buff *skb)
TCP_SKB_CB(skb)->bpf.data_end = skb->data + skb_headlen(skb);
}
static inline bool tcp_skb_bpf_ingress(const struct sk_buff *skb)
{
return TCP_SKB_CB(skb)->bpf.flags & BPF_F_INGRESS;
}
static inline struct sock *tcp_skb_bpf_redirect_fetch(struct sk_buff *skb)
{
return TCP_SKB_CB(skb)->bpf.sk_redir;
}
static inline void tcp_skb_bpf_redirect_clear(struct sk_buff *skb)
{
TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
}
#if IS_ENABLED(CONFIG_IPV6)
/* This is the variant of inet6_iif() that must be used by TCP,
* as TCP moves IP6CB into a different location in skb->cb[]
......@@ -2064,6 +2079,18 @@ void tcp_cleanup_ulp(struct sock *sk);
__MODULE_INFO(alias, alias_userspace, name); \
__MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name)
struct sk_msg;
struct sk_psock;
int tcp_bpf_init(struct sock *sk);
void tcp_bpf_reinit(struct sock *sk);
int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, u32 bytes,
int flags);
int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len);
int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
struct msghdr *msg, int len);
/* Call BPF_SOCK_OPS program that returns an int. If the return value
* is < 0, then the BPF op failed (for example if the loaded BPF
* program does not support the chosen operation or there is no BPF
......
kernel/bpf/Makefile
View file @ 604326b4
......@@ -13,11 +13,6 @@ ifeq ($(CONFIG_XDP_SOCKETS),y)
obj-$(CONFIG_BPF_SYSCALL) += xskmap.o
endif
obj-$(CONFIG_BPF_SYSCALL) += offload.o
ifeq ($(CONFIG_STREAM_PARSER),y)
ifeq ($(CONFIG_INET),y)
obj-$(CONFIG_BPF_SYSCALL) += sockmap.o
endif
endif
endif
ifeq ($(CONFIG_PERF_EVENTS),y)
obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
......
kernel/bpf/core.c
View file @ 604326b4
......@@ -1792,8 +1792,6 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
const struct bpf_func_proto bpf_get_current_comm_proto __weak;
const struct bpf_func_proto bpf_sock_map_update_proto __weak;
const struct bpf_func_proto bpf_sock_hash_update_proto __weak;
const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
const struct bpf_func_proto bpf_get_local_storage_proto __weak;
......
kernel/bpf/sockmap.c deleted 100644 → 0
View file @ 1243a51f
/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
/* A BPF sock_map is used to store sock objects. This is primarly used
* for doing socket redirect with BPF helper routines.
*
* A sock map may have BPF programs attached to it, currently a program
* used to parse packets and a program to provide a verdict and redirect
* decision on the packet are supported. Any programs attached to a sock
* map are inherited by sock objects when they are added to the map. If
* no BPF programs are attached the sock object may only be used for sock
* redirect.
*
* A sock object may be in multiple maps, but can only inherit a single
* parse or verdict program. If adding a sock object to a map would result
* in having multiple parsing programs the update will return an EBUSY error.
*
* For reference this program is similar to devmap used in XDP context
* reviewing these together may be useful. For an example please review
* ./samples/bpf/sockmap/.
*/
#include <linux/bpf.h>
#include <net/sock.h>
#include <linux/filter.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/workqueue.h>
#include <linux/list.h>
#include <linux/mm.h>
#include <net/strparser.h>
#include <net/tcp.h>
#include <linux/ptr_ring.h>
#include <net/inet_common.h>
#include <linux/sched/signal.h>
#define SOCK_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
struct bpf_sock_progs {
struct bpf_prog *bpf_tx_msg;
struct bpf_prog *bpf_parse;
struct bpf_prog *bpf_verdict;
};
struct bpf_stab {
struct bpf_map map;
struct sock **sock_map;
struct bpf_sock_progs progs;
raw_spinlock_t lock;
};
struct bucket {
struct hlist_head head;
raw_spinlock_t lock;
};
struct bpf_htab {
struct bpf_map map;
struct bucket *buckets;
atomic_t count;
u32 n_buckets;
u32 elem_size;
struct bpf_sock_progs progs;
struct rcu_head rcu;
};
struct htab_elem {
struct rcu_head rcu;
struct hlist_node hash_node;
u32 hash;
struct sock *sk;
char key[0];
};
enum smap_psock_state {
SMAP_TX_RUNNING,
};
struct smap_psock_map_entry {
struct list_head list;
struct bpf_map *map;
struct sock **entry;
struct htab_elem __rcu *hash_link;
};
struct smap_psock {
struct rcu_head rcu;
refcount_t refcnt;
/* datapath variables */
struct sk_buff_head rxqueue;
bool strp_enabled;
/* datapath error path cache across tx work invocations */
int save_rem;
int save_off;
struct sk_buff *save_skb;
/* datapath variables for tx_msg ULP */
struct sock *sk_redir;
int apply_bytes;
int cork_bytes;
int sg_size;
int eval;
struct sk_msg_buff *cork;
struct list_head ingress;
struct strparser strp;
struct bpf_prog *bpf_tx_msg;
struct bpf_prog *bpf_parse;
struct bpf_prog *bpf_verdict;
struct list_head maps;
spinlock_t maps_lock;
/* Back reference used when sock callback trigger sockmap operations */
struct sock *sock;
unsigned long state;
struct work_struct tx_work;
struct work_struct gc_work;
struct proto *sk_proto;
void (*save_unhash)(struct sock *sk);
void (*save_close)(struct sock *sk, long timeout);
void (*save_data_ready)(struct sock *sk);
void (*save_write_space)(struct sock *sk);
};
static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len);
static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
static void bpf_tcp_unhash(struct sock *sk);
static void bpf_tcp_close(struct sock *sk, long timeout);
static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
{
return rcu_dereference_sk_user_data(sk);
}
static bool bpf_tcp_stream_read(const struct sock *sk)
{
struct smap_psock *psock;
bool empty = true;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock))
goto out;
empty = list_empty(&psock->ingress);
out:
rcu_read_unlock();
return !empty;
}
enum {
SOCKMAP_IPV4,
SOCKMAP_IPV6,
SOCKMAP_NUM_PROTS,
};
enum {
SOCKMAP_BASE,
SOCKMAP_TX,
SOCKMAP_NUM_CONFIGS,
};
static struct proto *saved_tcpv6_prot __read_mostly;
static DEFINE_SPINLOCK(tcpv6_prot_lock);
static struct proto bpf_tcp_prots[SOCKMAP_NUM_PROTS][SOCKMAP_NUM_CONFIGS];
static void build_protos(struct proto prot[SOCKMAP_NUM_CONFIGS],
struct proto *base)
{
prot[SOCKMAP_BASE] = *base;
prot[SOCKMAP_BASE].unhash = bpf_tcp_unhash;
prot[SOCKMAP_BASE].close = bpf_tcp_close;
prot[SOCKMAP_BASE].recvmsg = bpf_tcp_recvmsg;
prot[SOCKMAP_BASE].stream_memory_read = bpf_tcp_stream_read;
prot[SOCKMAP_TX] = prot[SOCKMAP_BASE];
prot[SOCKMAP_TX].sendmsg = bpf_tcp_sendmsg;
prot[SOCKMAP_TX].sendpage = bpf_tcp_sendpage;
}
static void update_sk_prot(struct sock *sk, struct smap_psock *psock)
{
int family = sk->sk_family == AF_INET6 ? SOCKMAP_IPV6 : SOCKMAP_IPV4;
int conf = psock->bpf_tx_msg ? SOCKMAP_TX : SOCKMAP_BASE;
sk->sk_prot = &bpf_tcp_prots[family][conf];
}
static int bpf_tcp_init(struct sock *sk)
{
struct smap_psock *psock;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
return -EINVAL;
}
if (unlikely(psock->sk_proto)) {
rcu_read_unlock();
return -EBUSY;
}
psock->save_unhash = sk->sk_prot->unhash;
psock->save_close = sk->sk_prot->close;
psock->sk_proto = sk->sk_prot;
/* Build IPv6 sockmap whenever the address of tcpv6_prot changes */
if (sk->sk_family == AF_INET6 &&
unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
spin_lock_bh(&tcpv6_prot_lock);
if (likely(sk->sk_prot != saved_tcpv6_prot)) {
build_protos(bpf_tcp_prots[SOCKMAP_IPV6], sk->sk_prot);
smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
}
spin_unlock_bh(&tcpv6_prot_lock);
}
update_sk_prot(sk, psock);
rcu_read_unlock();
return 0;
}
static int __init bpf_sock_init(void)
{
build_protos(bpf_tcp_prots[SOCKMAP_IPV4], &tcp_prot);
return 0;
}
core_initcall(bpf_sock_init);
static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge);
static void bpf_tcp_release(struct sock *sk)
{
struct smap_psock *psock;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock))
goto out;
if (psock->cork) {
free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
psock->cork = NULL;
}
if (psock->sk_proto) {
sk->sk_prot = psock->sk_proto;
psock->sk_proto = NULL;
}
out:
rcu_read_unlock();
}
static struct htab_elem *lookup_elem_raw(struct hlist_head *head,
u32 hash, void *key, u32 key_size)
{
struct htab_elem *l;
hlist_for_each_entry_rcu(l, head, hash_node) {
if (l->hash == hash && !memcmp(&l->key, key, key_size))
return l;
}
return NULL;
}
static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
{
return &htab->buckets[hash & (htab->n_buckets - 1)];
}
static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash)
{
return &__select_bucket(htab, hash)->head;
}
static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
{
atomic_dec(&htab->count);
kfree_rcu(l, rcu);
}
static struct smap_psock_map_entry *psock_map_pop(struct sock *sk,
struct smap_psock *psock)
{
struct smap_psock_map_entry *e;
spin_lock_bh(&psock->maps_lock);
e = list_first_entry_or_null(&psock->maps,
struct smap_psock_map_entry,
list);
if (e)
list_del(&e->list);
spin_unlock_bh(&psock->maps_lock);
return e;
}
static void bpf_tcp_remove(struct sock *sk, struct smap_psock *psock)
{
struct smap_psock_map_entry *e;
struct sk_msg_buff *md, *mtmp;
struct sock *osk;
if (psock->cork) {
free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
psock->cork = NULL;
}
list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
list_del(&md->list);
free_start_sg(psock->sock, md, true);
kfree(md);
}
e = psock_map_pop(sk, psock);
while (e) {
if (e->entry) {
struct bpf_stab *stab = container_of(e->map, struct bpf_stab, map);
raw_spin_lock_bh(&stab->lock);
osk = *e->entry;
if (osk == sk) {
*e->entry = NULL;
smap_release_sock(psock, sk);
}
raw_spin_unlock_bh(&stab->lock);
} else {
struct htab_elem *link = rcu_dereference(e->hash_link);
struct bpf_htab *htab = container_of(e->map, struct bpf_htab, map);
struct hlist_head *head;
struct htab_elem *l;
struct bucket *b;
b = __select_bucket(htab, link->hash);
head = &b->head;
raw_spin_lock_bh(&b->lock);
l = lookup_elem_raw(head,
link->hash, link->key,
htab->map.key_size);
/* If another thread deleted this object skip deletion.
* The refcnt on psock may or may not be zero.
*/
if (l && l == link) {
hlist_del_rcu(&link->hash_node);
smap_release_sock(psock, link->sk);
free_htab_elem(htab, link);
}
raw_spin_unlock_bh(&b->lock);
}
kfree(e);
e = psock_map_pop(sk, psock);
}
}
static void bpf_tcp_unhash(struct sock *sk)
{
void (*unhash_fun)(struct sock *sk);
struct smap_psock *psock;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
if (sk->sk_prot->unhash)
sk->sk_prot->unhash(sk);
return;
}
unhash_fun = psock->save_unhash;
bpf_tcp_remove(sk, psock);
rcu_read_unlock();
unhash_fun(sk);
}
static void bpf_tcp_close(struct sock *sk, long timeout)
{
void (*close_fun)(struct sock *sk, long timeout);
struct smap_psock *psock;
lock_sock(sk);
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
release_sock(sk);
return sk->sk_prot->close(sk, timeout);
}
close_fun = psock->save_close;
bpf_tcp_remove(sk, psock);
rcu_read_unlock();
release_sock(sk);
close_fun(sk, timeout);
}
enum __sk_action {
__SK_DROP = 0,
__SK_PASS,
__SK_REDIRECT,
__SK_NONE,
};
static int memcopy_from_iter(struct sock *sk,
struct sk_msg_buff *md,
struct iov_iter *from, int bytes)
{
struct scatterlist *sg = md->sg_data;
int i = md->sg_curr, rc = -ENOSPC;
do {
int copy;
char *to;
if (md->sg_copybreak >= sg[i].length) {
md->sg_copybreak = 0;
if (++i == MAX_SKB_FRAGS)
i = 0;
if (i == md->sg_end)
break;
}
copy = sg[i].length - md->sg_copybreak;
to = sg_virt(&sg[i]) + md->sg_copybreak;
md->sg_copybreak += copy;
if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
rc = copy_from_iter_nocache(to, copy, from);
else
rc = copy_from_iter(to, copy, from);
if (rc != copy) {
rc = -EFAULT;
goto out;
}
bytes -= copy;
if (!bytes)
break;
md->sg_copybreak = 0;
if (++i == MAX_SKB_FRAGS)
i = 0;
} while (i != md->sg_end);
out:
md->sg_curr = i;
return rc;
}
static int bpf_tcp_push(struct sock *sk, int apply_bytes,
struct sk_msg_buff *md,
int flags, bool uncharge)
{
bool apply = apply_bytes;
struct scatterlist *sg;
int offset, ret = 0;
struct page *p;
size_t size;
while (1) {
sg = md->sg_data + md->sg_start;
size = (apply && apply_bytes < sg->length) ?
apply_bytes : sg->length;
offset = sg->offset;
tcp_rate_check_app_limited(sk);
p = sg_page(sg);
retry:
ret = do_tcp_sendpages(sk, p, offset, size, flags);
if (ret != size) {
if (ret > 0) {
if (apply)
apply_bytes -= ret;
sg->offset += ret;
sg->length -= ret;
size -= ret;
offset += ret;
if (uncharge)
sk_mem_uncharge(sk, ret);
goto retry;
}
return ret;
}
if (apply)
apply_bytes -= ret;
sg->offset += ret;
sg->length -= ret;
if (uncharge)
sk_mem_uncharge(sk, ret);
if (!sg->length) {
put_page(p);
md->sg_start++;
if (md->sg_start == MAX_SKB_FRAGS)
md->sg_start = 0;
sg_init_table(sg, 1);
if (md->sg_start == md->sg_end)
break;
}
if (apply && !apply_bytes)
break;
}
return 0;
}
static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md)
{
struct scatterlist *sg = md->sg_data + md->sg_start;
if (md->sg_copy[md->sg_start]) {
md->data = md->data_end = 0;
} else {
md->data = sg_virt(sg);
md->data_end = md->data + sg->length;
}
}
static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md)
{
struct scatterlist *sg = md->sg_data;
int i = md->sg_start;
do {
int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length;
sk_mem_uncharge(sk, uncharge);
bytes -= uncharge;
if (!bytes)
break;
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
} while (i != md->sg_end);
}
static void free_bytes_sg(struct sock *sk, int bytes,
struct sk_msg_buff *md, bool charge)
{
struct scatterlist *sg = md->sg_data;
int i = md->sg_start, free;
while (bytes && sg[i].length) {
free = sg[i].length;
if (bytes < free) {
sg[i].length -= bytes;
sg[i].offset += bytes;
if (charge)
sk_mem_uncharge(sk, bytes);
break;
}
if (charge)
sk_mem_uncharge(sk, sg[i].length);
put_page(sg_page(&sg[i]));
bytes -= sg[i].length;
sg[i].length = 0;
sg[i].page_link = 0;
sg[i].offset = 0;
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
}
md->sg_start = i;
}
static int free_sg(struct sock *sk, int start,
struct sk_msg_buff *md, bool charge)
{
struct scatterlist *sg = md->sg_data;
int i = start, free = 0;
while (sg[i].length) {
free += sg[i].length;
if (charge)
sk_mem_uncharge(sk, sg[i].length);
if (!md->skb)
put_page(sg_page(&sg[i]));
sg[i].length = 0;
sg[i].page_link = 0;
sg[i].offset = 0;
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
}
consume_skb(md->skb);
return free;
}
static int free_start_sg(struct sock *sk, struct sk_msg_buff *md, bool charge)
{
int free = free_sg(sk, md->sg_start, md, charge);
md->sg_start = md->sg_end;
return free;
}
static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md)
{
return free_sg(sk, md->sg_curr, md, true);
}
static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md)
{
return ((_rc == SK_PASS) ?
(md->sk_redir ? __SK_REDIRECT : __SK_PASS) :
__SK_DROP);
}
static unsigned int smap_do_tx_msg(struct sock *sk,
struct smap_psock *psock,
struct sk_msg_buff *md)
{
struct bpf_prog *prog;
unsigned int rc, _rc;
preempt_disable();
rcu_read_lock();
/* If the policy was removed mid-send then default to 'accept' */
prog = READ_ONCE(psock->bpf_tx_msg);
if (unlikely(!prog)) {
_rc = SK_PASS;
goto verdict;
}
bpf_compute_data_pointers_sg(md);
md->sk = sk;
rc = (*prog->bpf_func)(md, prog->insnsi);
psock->apply_bytes = md->apply_bytes;
/* Moving return codes from UAPI namespace into internal namespace */
_rc = bpf_map_msg_verdict(rc, md);
/* The psock has a refcount on the sock but not on the map and because
* we need to drop rcu read lock here its possible the map could be
* removed between here and when we need it to execute the sock
* redirect. So do the map lookup now for future use.
*/
if (_rc == __SK_REDIRECT) {
if (psock->sk_redir)
sock_put(psock->sk_redir);
psock->sk_redir = do_msg_redirect_map(md);
if (!psock->sk_redir) {
_rc = __SK_DROP;
goto verdict;
}
sock_hold(psock->sk_redir);
}
verdict:
rcu_read_unlock();
preempt_enable();
return _rc;
}
static int bpf_tcp_ingress(struct sock *sk, int apply_bytes,
struct smap_psock *psock,
struct sk_msg_buff *md, int flags)
{
bool apply = apply_bytes;
size_t size, copied = 0;
struct sk_msg_buff *r;
int err = 0, i;
r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL);
if (unlikely(!r))
return -ENOMEM;
lock_sock(sk);
r->sg_start = md->sg_start;
i = md->sg_start;
do {
size = (apply && apply_bytes < md->sg_data[i].length) ?
apply_bytes : md->sg_data[i].length;
if (!sk_wmem_schedule(sk, size)) {
if (!copied)
err = -ENOMEM;
break;
}
sk_mem_charge(sk, size);
r->sg_data[i] = md->sg_data[i];
r->sg_data[i].length = size;
md->sg_data[i].length -= size;
md->sg_data[i].offset += size;
copied += size;
if (md->sg_data[i].length) {
get_page(sg_page(&r->sg_data[i]));
r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1;
} else {
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
r->sg_end = i;
}
if (apply) {
apply_bytes -= size;
if (!apply_bytes)
break;
}
} while (i != md->sg_end);
md->sg_start = i;
if (!err) {
list_add_tail(&r->list, &psock->ingress);
sk->sk_data_ready(sk);
} else {
free_start_sg(sk, r, true);
kfree(r);
}
release_sock(sk);
return err;
}
static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send,
struct sk_msg_buff *md,
int flags)
{
bool ingress = !!(md->flags & BPF_F_INGRESS);
struct smap_psock *psock;
int err = 0;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock))
goto out_rcu;
if (!refcount_inc_not_zero(&psock->refcnt))
goto out_rcu;
rcu_read_unlock();
if (ingress) {
err = bpf_tcp_ingress(sk, send, psock, md, flags);
} else {
lock_sock(sk);
err = bpf_tcp_push(sk, send, md, flags, false);
release_sock(sk);
}
smap_release_sock(psock, sk);
return err;
out_rcu:
rcu_read_unlock();
return 0;
}
static inline void bpf_md_init(struct smap_psock *psock)
{
if (!psock->apply_bytes) {
psock->eval = __SK_NONE;
if (psock->sk_redir) {
sock_put(psock->sk_redir);
psock->sk_redir = NULL;
}
}
}
static void apply_bytes_dec(struct smap_psock *psock, int i)
{
if (psock->apply_bytes) {
if (psock->apply_bytes < i)
psock->apply_bytes = 0;
else
psock->apply_bytes -= i;
}
}
static int bpf_exec_tx_verdict(struct smap_psock *psock,
struct sk_msg_buff *m,
struct sock *sk,
int *copied, int flags)
{
bool cork = false, enospc = (m->sg_start == m->sg_end);
struct sock *redir;
int err = 0;
int send;
more_data:
if (psock->eval == __SK_NONE)
psock->eval = smap_do_tx_msg(sk, psock, m);
if (m->cork_bytes &&
m->cork_bytes > psock->sg_size && !enospc) {
psock->cork_bytes = m->cork_bytes - psock->sg_size;
if (!psock->cork) {
psock->cork = kcalloc(1,
sizeof(struct sk_msg_buff),
GFP_ATOMIC | __GFP_NOWARN);
if (!psock->cork) {
err = -ENOMEM;
goto out_err;
}
}
memcpy(psock->cork, m, sizeof(*m));
goto out_err;
}
send = psock->sg_size;
if (psock->apply_bytes && psock->apply_bytes < send)
send = psock->apply_bytes;
switch (psock->eval) {
case __SK_PASS:
err = bpf_tcp_push(sk, send, m, flags, true);
if (unlikely(err)) {
*copied -= free_start_sg(sk, m, true);
break;
}
apply_bytes_dec(psock, send);
psock->sg_size -= send;
break;
case __SK_REDIRECT:
redir = psock->sk_redir;
apply_bytes_dec(psock, send);
if (psock->cork) {
cork = true;
psock->cork = NULL;
}
return_mem_sg(sk, send, m);
release_sock(sk);
err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags);
lock_sock(sk);
if (unlikely(err < 0)) {
int free = free_start_sg(sk, m, false);
psock->sg_size = 0;
if (!cork)
*copied -= free;
} else {
psock->sg_size -= send;
}
if (cork) {
free_start_sg(sk, m, true);
psock->sg_size = 0;
kfree(m);
m = NULL;
err = 0;
}
break;
case __SK_DROP:
default:
free_bytes_sg(sk, send, m, true);
apply_bytes_dec(psock, send);
*copied -= send;
psock->sg_size -= send;
err = -EACCES;
break;
}
if (likely(!err)) {
bpf_md_init(psock);
if (m &&
m->sg_data[m->sg_start].page_link &&
m->sg_data[m->sg_start].length)
goto more_data;
}
out_err:
return err;
}
static int bpf_wait_data(struct sock *sk,
struct smap_psock *psk, int flags,
long timeo, int *err)
{
int rc;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
rc = sk_wait_event(sk, &timeo,
!list_empty(&psk->ingress) ||
!skb_queue_empty(&sk->sk_receive_queue),
&wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
remove_wait_queue(sk_sleep(sk), &wait);
return rc;
}
static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len)
{
struct iov_iter *iter = &msg->msg_iter;
struct smap_psock *psock;
int copied = 0;
if (unlikely(flags & MSG_ERRQUEUE))
return inet_recv_error(sk, msg, len, addr_len);
if (!skb_queue_empty(&sk->sk_receive_queue))
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock))
goto out;
if (unlikely(!refcount_inc_not_zero(&psock->refcnt)))
goto out;
rcu_read_unlock();
lock_sock(sk);
bytes_ready:
while (copied != len) {
struct scatterlist *sg;
struct sk_msg_buff *md;
int i;
md = list_first_entry_or_null(&psock->ingress,
struct sk_msg_buff, list);
if (unlikely(!md))
break;
i = md->sg_start;
do {
struct page *page;
int n, copy;
sg = &md->sg_data[i];
copy = sg->length;
page = sg_page(sg);
if (copied + copy > len)
copy = len - copied;
n = copy_page_to_iter(page, sg->offset, copy, iter);
if (n != copy) {
md->sg_start = i;
release_sock(sk);
smap_release_sock(psock, sk);
return -EFAULT;
}
copied += copy;
sg->offset += copy;
sg->length -= copy;
sk_mem_uncharge(sk, copy);
if (!sg->length) {
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
if (!md->skb)
put_page(page);
}
if (copied == len)
break;
} while (i != md->sg_end);
md->sg_start = i;
if (!sg->length && md->sg_start == md->sg_end) {
list_del(&md->list);
consume_skb(md->skb);
kfree(md);
}
}
if (!copied) {
long timeo;
int data;
int err = 0;
timeo = sock_rcvtimeo(sk, nonblock);
data = bpf_wait_data(sk, psock, flags, timeo, &err);
if (data) {
if (!skb_queue_empty(&sk->sk_receive_queue)) {
release_sock(sk);
smap_release_sock(psock, sk);
copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
return copied;
}
goto bytes_ready;
}
if (err)
copied = err;
}
release_sock(sk);
smap_release_sock(psock, sk);
return copied;
out:
rcu_read_unlock();
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
}
static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS;
struct sk_msg_buff md = {0};
unsigned int sg_copy = 0;
struct smap_psock *psock;
int copied = 0, err = 0;
struct scatterlist *sg;
long timeo;
/* Its possible a sock event or user removed the psock _but_ the ops
* have not been reprogrammed yet so we get here. In this case fallback
* to tcp_sendmsg. Note this only works because we _only_ ever allow
* a single ULP there is no hierarchy here.
*/
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
return tcp_sendmsg(sk, msg, size);
}
/* Increment the psock refcnt to ensure its not released while sending a
* message. Required because sk lookup and bpf programs are used in
* separate rcu critical sections. Its OK if we lose the map entry
* but we can't lose the sock reference.
*/
if (!refcount_inc_not_zero(&psock->refcnt)) {
rcu_read_unlock();
return tcp_sendmsg(sk, msg, size);
}
sg = md.sg_data;
sg_init_marker(sg, MAX_SKB_FRAGS);
rcu_read_unlock();
lock_sock(sk);
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
while (msg_data_left(msg)) {
struct sk_msg_buff *m = NULL;
bool enospc = false;
int copy;
if (sk->sk_err) {
err = -sk->sk_err;
goto out_err;
}
copy = msg_data_left(msg);
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
m = psock->cork_bytes ? psock->cork : &md;
m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end;
err = sk_alloc_sg(sk, copy, m->sg_data,
m->sg_start, &m->sg_end, &sg_copy,
m->sg_end - 1);
if (err) {
if (err != -ENOSPC)
goto wait_for_memory;
enospc = true;
copy = sg_copy;
}
err = memcopy_from_iter(sk, m, &msg->msg_iter, copy);
if (err < 0) {
free_curr_sg(sk, m);
goto out_err;
}
psock->sg_size += copy;
copied += copy;
sg_copy = 0;
/* When bytes are being corked skip running BPF program and
* applying verdict unless there is no more buffer space. In
* the ENOSPC case simply run BPF prorgram with currently
* accumulated data. We don't have much choice at this point
* we could try extending the page frags or chaining complex
* frags but even in these cases _eventually_ we will hit an
* OOM scenario. More complex recovery schemes may be
* implemented in the future, but BPF programs must handle
* the case where apply_cork requests are not honored. The
* canonical method to verify this is to check data length.
*/
if (psock->cork_bytes) {
if (copy > psock->cork_bytes)
psock->cork_bytes = 0;
else
psock->cork_bytes -= copy;
if (psock->cork_bytes && !enospc)
goto out_cork;
/* All cork bytes accounted for re-run filter */
psock->eval = __SK_NONE;
psock->cork_bytes = 0;
}
err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
if (unlikely(err < 0))
goto out_err;
continue;
wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
err = sk_stream_wait_memory(sk, &timeo);
if (err) {
if (m && m != psock->cork)
free_start_sg(sk, m, true);
goto out_err;
}
}
out_err:
if (err < 0)
err = sk_stream_error(sk, msg->msg_flags, err);
out_cork:
release_sock(sk);
smap_release_sock(psock, sk);
return copied ? copied : err;
}
static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags)
{
struct sk_msg_buff md = {0}, *m = NULL;
int err = 0, copied = 0;
struct smap_psock *psock;
struct scatterlist *sg;
bool enospc = false;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock))
goto accept;
if (!refcount_inc_not_zero(&psock->refcnt))
goto accept;
rcu_read_unlock();
lock_sock(sk);
if (psock->cork_bytes) {
m = psock->cork;
sg = &m->sg_data[m->sg_end];
} else {
m = &md;
sg = m->sg_data;
sg_init_marker(sg, MAX_SKB_FRAGS);
}
/* Catch case where ring is full and sendpage is stalled. */
if (unlikely(m->sg_end == m->sg_start &&
m->sg_data[m->sg_end].length))
goto out_err;
psock->sg_size += size;
sg_set_page(sg, page, size, offset);
get_page(page);
m->sg_copy[m->sg_end] = true;
sk_mem_charge(sk, size);
m->sg_end++;
copied = size;
if (m->sg_end == MAX_SKB_FRAGS)
m->sg_end = 0;
if (m->sg_end == m->sg_start)
enospc = true;
if (psock->cork_bytes) {
if (size > psock->cork_bytes)
psock->cork_bytes = 0;
else
psock->cork_bytes -= size;
if (psock->cork_bytes && !enospc)
goto out_err;
/* All cork bytes accounted for re-run filter */
psock->eval = __SK_NONE;
psock->cork_bytes = 0;
}
err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
out_err:
release_sock(sk);
smap_release_sock(psock, sk);
return copied ? copied : err;
accept:
rcu_read_unlock();
return tcp_sendpage(sk, page, offset, size, flags);
}
static void bpf_tcp_msg_add(struct smap_psock *psock,
struct sock *sk,
struct bpf_prog *tx_msg)
{
struct bpf_prog *orig_tx_msg;
orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg);
if (orig_tx_msg)
bpf_prog_put(orig_tx_msg);
}
static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
{
struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict);
int rc;
if (unlikely(!prog))
return __SK_DROP;
skb_orphan(skb);
/* We need to ensure that BPF metadata for maps is also cleared
* when we orphan the skb so that we don't have the possibility
* to reference a stale map.
*/
TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
skb->sk = psock->sock;
bpf_compute_data_end_sk_skb(skb);
preempt_disable();
rc = (*prog->bpf_func)(skb, prog->insnsi);
preempt_enable();
skb->sk = NULL;
/* Moving return codes from UAPI namespace into internal namespace */
return rc == SK_PASS ?
(TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) :
__SK_DROP;
}
static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb)
{
struct sock *sk = psock->sock;
int copied = 0, num_sg;
struct sk_msg_buff *r;
r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC);
if (unlikely(!r))
return -EAGAIN;
if (!sk_rmem_schedule(sk, skb, skb->len)) {
kfree(r);
return -EAGAIN;
}
sg_init_table(r->sg_data, MAX_SKB_FRAGS);
num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len);
if (unlikely(num_sg < 0)) {
kfree(r);
return num_sg;
}
sk_mem_charge(sk, skb->len);
copied = skb->len;
r->sg_start = 0;
r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg;
r->skb = skb;
list_add_tail(&r->list, &psock->ingress);
sk->sk_data_ready(sk);
return copied;
}
static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb)
{
struct smap_psock *peer;
struct sock *sk;
__u32 in;
int rc;
rc = smap_verdict_func(psock, skb);
switch (rc) {
case __SK_REDIRECT:
sk = do_sk_redirect_map(skb);
if (!sk) {
kfree_skb(skb);
break;
}
peer = smap_psock_sk(sk);
in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) ||
!test_bit(SMAP_TX_RUNNING, &peer->state))) {
kfree_skb(skb);
break;
}
if (!in && sock_writeable(sk)) {
skb_set_owner_w(skb, sk);
skb_queue_tail(&peer->rxqueue, skb);
schedule_work(&peer->tx_work);
break;
} else if (in &&
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
skb_queue_tail(&peer->rxqueue, skb);
schedule_work(&peer->tx_work);
break;
}
/* Fall through and free skb otherwise */
case __SK_DROP:
default:
kfree_skb(skb);
}
}
static void smap_report_sk_error(struct smap_psock *psock, int err)
{
struct sock *sk = psock->sock;
sk->sk_err = err;
sk->sk_error_report(sk);
}
static void smap_read_sock_strparser(struct strparser *strp,
struct sk_buff *skb)
{
struct smap_psock *psock;
rcu_read_lock();
psock = container_of(strp, struct smap_psock, strp);
smap_do_verdict(psock, skb);
rcu_read_unlock();
}
/* Called with lock held on socket */
static void smap_data_ready(struct sock *sk)
{
struct smap_psock *psock;
rcu_read_lock();
psock = smap_psock_sk(sk);
if (likely(psock)) {
write_lock_bh(&sk->sk_callback_lock);
strp_data_ready(&psock->strp);
write_unlock_bh(&sk->sk_callback_lock);
}
rcu_read_unlock();
}
static void smap_tx_work(struct work_struct *w)
{
struct smap_psock *psock;
struct sk_buff *skb;
int rem, off, n;
psock = container_of(w, struct smap_psock, tx_work);
/* lock sock to avoid losing sk_socket at some point during loop */
lock_sock(psock->sock);
if (psock->save_skb) {
skb = psock->save_skb;
rem = psock->save_rem;
off = psock->save_off;
psock->save_skb = NULL;
goto start;
}
while ((skb = skb_dequeue(&psock->rxqueue))) {
__u32 flags;
rem = skb->len;
off = 0;
start:
flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
do {
if (likely(psock->sock->sk_socket)) {
if (flags)
n = smap_do_ingress(psock, skb);
else
n = skb_send_sock_locked(psock->sock,
skb, off, rem);
} else {
n = -EINVAL;
}
if (n <= 0) {
if (n == -EAGAIN) {
/* Retry when space is available */
psock->save_skb = skb;
psock->save_rem = rem;
psock->save_off = off;
goto out;
}
/* Hard errors break pipe and stop xmit */
smap_report_sk_error(psock, n ? -n : EPIPE);
clear_bit(SMAP_TX_RUNNING, &psock->state);
kfree_skb(skb);
goto out;
}
rem -= n;
off += n;
} while (rem);
if (!flags)
kfree_skb(skb);
}
out:
release_sock(psock->sock);
}
static void smap_write_space(struct sock *sk)
{
struct smap_psock *psock;
void (*write_space)(struct sock *sk);
rcu_read_lock();
psock = smap_psock_sk(sk);
if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state)))
schedule_work(&psock->tx_work);
write_space = psock->save_write_space;
rcu_read_unlock();
write_space(sk);
}
static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
{
if (!psock->strp_enabled)
return;
sk->sk_data_ready = psock->save_data_ready;
sk->sk_write_space = psock->save_write_space;
psock->save_data_ready = NULL;
psock->save_write_space = NULL;
strp_stop(&psock->strp);
psock->strp_enabled = false;
}
static void smap_destroy_psock(struct rcu_head *rcu)
{
struct smap_psock *psock = container_of(rcu,
struct smap_psock, rcu);
/* Now that a grace period has passed there is no longer
* any reference to this sock in the sockmap so we can
* destroy the psock, strparser, and bpf programs. But,
* because we use workqueue sync operations we can not
* do it in rcu context
*/
schedule_work(&psock->gc_work);
}
static bool psock_is_smap_sk(struct sock *sk)
{
return inet_csk(sk)->icsk_ulp_ops == &bpf_tcp_ulp_ops;
}
static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
{
if (refcount_dec_and_test(&psock->refcnt)) {
if (psock_is_smap_sk(sock))
bpf_tcp_release(sock);
write_lock_bh(&sock->sk_callback_lock);
smap_stop_sock(psock, sock);
write_unlock_bh(&sock->sk_callback_lock);
clear_bit(SMAP_TX_RUNNING, &psock->state);
rcu_assign_sk_user_data(sock, NULL);
call_rcu_sched(&psock->rcu, smap_destroy_psock);
}
}
static int smap_parse_func_strparser(struct strparser *strp,
struct sk_buff *skb)
{
struct smap_psock *psock;
struct bpf_prog *prog;
int rc;
rcu_read_lock();
psock = container_of(strp, struct smap_psock, strp);
prog = READ_ONCE(psock->bpf_parse);
if (unlikely(!prog)) {
rcu_read_unlock();
return skb->len;
}
/* Attach socket for bpf program to use if needed we can do this
* because strparser clones the skb before handing it to a upper
* layer, meaning skb_orphan has been called. We NULL sk on the
* way out to ensure we don't trigger a BUG_ON in skb/sk operations
* later and because we are not charging the memory of this skb to
* any socket yet.
*/
skb->sk = psock->sock;
bpf_compute_data_end_sk_skb(skb);
rc = (*prog->bpf_func)(skb, prog->insnsi);
skb->sk = NULL;
rcu_read_unlock();
return rc;
}
static int smap_read_sock_done(struct strparser *strp, int err)
{
return err;
}
static int smap_init_sock(struct smap_psock *psock,
struct sock *sk)
{
static const struct strp_callbacks cb = {
.rcv_msg = smap_read_sock_strparser,
.parse_msg = smap_parse_func_strparser,
.read_sock_done = smap_read_sock_done,
};
return strp_init(&psock->strp, sk, &cb);
}
static void smap_init_progs(struct smap_psock *psock,
struct bpf_prog *verdict,
struct bpf_prog *parse)
{
struct bpf_prog *orig_parse, *orig_verdict;
orig_parse = xchg(&psock->bpf_parse, parse);
orig_verdict = xchg(&psock->bpf_verdict, verdict);
if (orig_verdict)
bpf_prog_put(orig_verdict);
if (orig_parse)
bpf_prog_put(orig_parse);
}
static void smap_start_sock(struct smap_psock *psock, struct sock *sk)
{
if (sk->sk_data_ready == smap_data_ready)
return;
psock->save_data_ready = sk->sk_data_ready;
psock->save_write_space = sk->sk_write_space;
sk->sk_data_ready = smap_data_ready;
sk->sk_write_space = smap_write_space;
psock->strp_enabled = true;
}
static void sock_map_remove_complete(struct bpf_stab *stab)
{
bpf_map_area_free(stab->sock_map);
kfree(stab);
}
static void smap_gc_work(struct work_struct *w)
{
struct smap_psock_map_entry *e, *tmp;
struct sk_msg_buff *md, *mtmp;
struct smap_psock *psock;
psock = container_of(w, struct smap_psock, gc_work);
/* no callback lock needed because we already detached sockmap ops */
if (psock->strp_enabled)
strp_done(&psock->strp);
cancel_work_sync(&psock->tx_work);
__skb_queue_purge(&psock->rxqueue);
/* At this point all strparser and xmit work must be complete */
if (psock->bpf_parse)
bpf_prog_put(psock->bpf_parse);
if (psock->bpf_verdict)
bpf_prog_put(psock->bpf_verdict);
if (psock->bpf_tx_msg)
bpf_prog_put(psock->bpf_tx_msg);
if (psock->cork) {
free_start_sg(psock->sock, psock->cork, true);
kfree(psock->cork);
}
list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
list_del(&md->list);
free_start_sg(psock->sock, md, true);
kfree(md);
}
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
list_del(&e->list);
kfree(e);
}
if (psock->sk_redir)
sock_put(psock->sk_redir);
sock_put(psock->sock);
kfree(psock);
}
static struct smap_psock *smap_init_psock(struct sock *sock, int node)
{
struct smap_psock *psock;
psock = kzalloc_node(sizeof(struct smap_psock),
GFP_ATOMIC | __GFP_NOWARN,
node);
if (!psock)
return ERR_PTR(-ENOMEM);
psock->eval = __SK_NONE;
psock->sock = sock;
skb_queue_head_init(&psock->rxqueue);
INIT_WORK(&psock->tx_work, smap_tx_work);
INIT_WORK(&psock->gc_work, smap_gc_work);
INIT_LIST_HEAD(&psock->maps);
INIT_LIST_HEAD(&psock->ingress);
refcount_set(&psock->refcnt, 1);
spin_lock_init(&psock->maps_lock);
rcu_assign_sk_user_data(sock, psock);
sock_hold(sock);
return psock;
}
static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
{
struct bpf_stab *stab;
u64 cost;
int err;
if (!capable(CAP_NET_ADMIN))
return ERR_PTR(-EPERM);
/* check sanity of attributes */
if (attr->max_entries == 0 || attr->key_size != 4 ||
attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
return ERR_PTR(-EINVAL);
stab = kzalloc(sizeof(*stab), GFP_USER);
if (!stab)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&stab->map, attr);
raw_spin_lock_init(&stab->lock);
/* make sure page count doesn't overflow */
cost = (u64) stab->map.max_entries * sizeof(struct sock *);
err = -EINVAL;
if (cost >= U32_MAX - PAGE_SIZE)
goto free_stab;
stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
/* if map size is larger than memlock limit, reject it early */
err = bpf_map_precharge_memlock(stab->map.pages);
if (err)
goto free_stab;
err = -ENOMEM;
stab->sock_map = bpf_map_area_alloc(stab->map.max_entries *
sizeof(struct sock *),
stab->map.numa_node);
if (!stab->sock_map)
goto free_stab;
return &stab->map;
free_stab:
kfree(stab);
return ERR_PTR(err);
}
static void smap_list_map_remove(struct smap_psock *psock,
struct sock **entry)
{
struct smap_psock_map_entry *e, *tmp;
spin_lock_bh(&psock->maps_lock);
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
if (e->entry == entry) {
list_del(&e->list);
kfree(e);
}
}
spin_unlock_bh(&psock->maps_lock);
}
static void smap_list_hash_remove(struct smap_psock *psock,
struct htab_elem *hash_link)
{
struct smap_psock_map_entry *e, *tmp;
spin_lock_bh(&psock->maps_lock);
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
struct htab_elem *c = rcu_dereference(e->hash_link);
if (c == hash_link) {
list_del(&e->list);
kfree(e);
}
}
spin_unlock_bh(&psock->maps_lock);
}
static void sock_map_free(struct bpf_map *map)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
int i;
synchronize_rcu();
/* At this point no update, lookup or delete operations can happen.
* However, be aware we can still get a socket state event updates,
* and data ready callabacks that reference the psock from sk_user_data
* Also psock worker threads are still in-flight. So smap_release_sock
* will only free the psock after cancel_sync on the worker threads
* and a grace period expire to ensure psock is really safe to remove.
*/
rcu_read_lock();
raw_spin_lock_bh(&stab->lock);
for (i = 0; i < stab->map.max_entries; i++) {
struct smap_psock *psock;
struct sock *sock;
sock = stab->sock_map[i];
if (!sock)
continue;
stab->sock_map[i] = NULL;
psock = smap_psock_sk(sock);
/* This check handles a racing sock event that can get the
* sk_callback_lock before this case but after xchg happens
* causing the refcnt to hit zero and sock user data (psock)
* to be null and queued for garbage collection.
*/
if (likely(psock)) {
smap_list_map_remove(psock, &stab->sock_map[i]);
smap_release_sock(psock, sock);
}
}
raw_spin_unlock_bh(&stab->lock);
rcu_read_unlock();
sock_map_remove_complete(stab);
}
static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
u32 i = key ? *(u32 *)key : U32_MAX;
u32 *next = (u32 *)next_key;
if (i >= stab->map.max_entries) {
*next = 0;
return 0;
}
if (i == stab->map.max_entries - 1)
return -ENOENT;
*next = i + 1;
return 0;
}
struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
if (key >= map->max_entries)
return NULL;
return READ_ONCE(stab->sock_map[key]);
}
static int sock_map_delete_elem(struct bpf_map *map, void *key)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
struct smap_psock *psock;
int k = *(u32 *)key;
struct sock *sock;
if (k >= map->max_entries)
return -EINVAL;
raw_spin_lock_bh(&stab->lock);
sock = stab->sock_map[k];
stab->sock_map[k] = NULL;
raw_spin_unlock_bh(&stab->lock);
if (!sock)
return -EINVAL;
psock = smap_psock_sk(sock);
if (!psock)
return 0;
if (psock->bpf_parse) {
write_lock_bh(&sock->sk_callback_lock);
smap_stop_sock(psock, sock);
write_unlock_bh(&sock->sk_callback_lock);
}
smap_list_map_remove(psock, &stab->sock_map[k]);
smap_release_sock(psock, sock);
return 0;
}
/* Locking notes: Concurrent updates, deletes, and lookups are allowed and are
* done inside rcu critical sections. This ensures on updates that the psock
* will not be released via smap_release_sock() until concurrent updates/deletes
* complete. All operations operate on sock_map using cmpxchg and xchg
* operations to ensure we do not get stale references. Any reads into the
* map must be done with READ_ONCE() because of this.
*
* A psock is destroyed via call_rcu and after any worker threads are cancelled
* and syncd so we are certain all references from the update/lookup/delete
* operations as well as references in the data path are no longer in use.
*
* Psocks may exist in multiple maps, but only a single set of parse/verdict
* programs may be inherited from the maps it belongs to. A reference count
* is kept with the total number of references to the psock from all maps. The
* psock will not be released until this reaches zero. The psock and sock
* user data data use the sk_callback_lock to protect critical data structures
* from concurrent access. This allows us to avoid two updates from modifying
* the user data in sock and the lock is required anyways for modifying
* callbacks, we simply increase its scope slightly.
*
* Rules to follow,
* - psock must always be read inside RCU critical section
* - sk_user_data must only be modified inside sk_callback_lock and read
* inside RCU critical section.
* - psock->maps list must only be read & modified inside sk_callback_lock
* - sock_map must use READ_ONCE and (cmp)xchg operations
* - BPF verdict/parse programs must use READ_ONCE and xchg operations
*/
static int __sock_map_ctx_update_elem(struct bpf_map *map,
struct bpf_sock_progs *progs,
struct sock *sock,
void *key)
{
struct bpf_prog *verdict, *parse, *tx_msg;
struct smap_psock *psock;
bool new = false;
int err = 0;
/* 1. If sock map has BPF programs those will be inherited by the
* sock being added. If the sock is already attached to BPF programs
* this results in an error.
*/
verdict = READ_ONCE(progs->bpf_verdict);
parse = READ_ONCE(progs->bpf_parse);
tx_msg = READ_ONCE(progs->bpf_tx_msg);
if (parse && verdict) {
/* bpf prog refcnt may be zero if a concurrent attach operation
* removes the program after the above READ_ONCE() but before
* we increment the refcnt. If this is the case abort with an
* error.
*/
verdict = bpf_prog_inc_not_zero(verdict);
if (IS_ERR(verdict))
return PTR_ERR(verdict);
parse = bpf_prog_inc_not_zero(parse);
if (IS_ERR(parse)) {
bpf_prog_put(verdict);
return PTR_ERR(parse);
}
}
if (tx_msg) {
tx_msg = bpf_prog_inc_not_zero(tx_msg);
if (IS_ERR(tx_msg)) {
if (parse && verdict) {
bpf_prog_put(parse);
bpf_prog_put(verdict);
}
return PTR_ERR(tx_msg);
}
}
psock = smap_psock_sk(sock);
/* 2. Do not allow inheriting programs if psock exists and has
* already inherited programs. This would create confusion on
* which parser/verdict program is running. If no psock exists
* create one. Inside sk_callback_lock to ensure concurrent create
* doesn't update user data.
*/
if (psock) {
if (!psock_is_smap_sk(sock)) {
err = -EBUSY;
goto out_progs;
}
if (READ_ONCE(psock->bpf_parse) && parse) {
err = -EBUSY;
goto out_progs;
}
if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) {
err = -EBUSY;
goto out_progs;
}
if (!refcount_inc_not_zero(&psock->refcnt)) {
err = -EAGAIN;
goto out_progs;
}
} else {
psock = smap_init_psock(sock, map->numa_node);
if (IS_ERR(psock)) {
err = PTR_ERR(psock);
goto out_progs;
}
set_bit(SMAP_TX_RUNNING, &psock->state);
new = true;
}
/* 3. At this point we have a reference to a valid psock that is
* running. Attach any BPF programs needed.
*/
if (tx_msg)
bpf_tcp_msg_add(psock, sock, tx_msg);
if (new) {
err = bpf_tcp_init(sock);
if (err)
goto out_free;
}
if (parse && verdict && !psock->strp_enabled) {
err = smap_init_sock(psock, sock);
if (err)
goto out_free;
smap_init_progs(psock, verdict, parse);
write_lock_bh(&sock->sk_callback_lock);
smap_start_sock(psock, sock);
write_unlock_bh(&sock->sk_callback_lock);
}
return err;
out_free:
smap_release_sock(psock, sock);
out_progs:
if (parse && verdict) {
bpf_prog_put(parse);
bpf_prog_put(verdict);
}
if (tx_msg)
bpf_prog_put(tx_msg);
return err;
}
static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
struct bpf_map *map,
void *key, u64 flags)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
struct bpf_sock_progs *progs = &stab->progs;
struct sock *osock, *sock = skops->sk;
struct smap_psock_map_entry *e;
struct smap_psock *psock;
u32 i = *(u32 *)key;
int err;
if (unlikely(flags > BPF_EXIST))
return -EINVAL;
if (unlikely(i >= stab->map.max_entries))
return -E2BIG;
e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
if (!e)
return -ENOMEM;
err = __sock_map_ctx_update_elem(map, progs, sock, key);
if (err)
goto out;
/* psock guaranteed to be present. */
psock = smap_psock_sk(sock);
raw_spin_lock_bh(&stab->lock);
osock = stab->sock_map[i];
if (osock && flags == BPF_NOEXIST) {
err = -EEXIST;
goto out_unlock;
}
if (!osock && flags == BPF_EXIST) {
err = -ENOENT;
goto out_unlock;
}
e->entry = &stab->sock_map[i];
e->map = map;
spin_lock_bh(&psock->maps_lock);
list_add_tail(&e->list, &psock->maps);
spin_unlock_bh(&psock->maps_lock);
stab->sock_map[i] = sock;
if (osock) {
psock = smap_psock_sk(osock);
smap_list_map_remove(psock, &stab->sock_map[i]);
smap_release_sock(psock, osock);
}
raw_spin_unlock_bh(&stab->lock);
return 0;
out_unlock:
smap_release_sock(psock, sock);
raw_spin_unlock_bh(&stab->lock);
out:
kfree(e);
return err;
}
int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
{
struct bpf_sock_progs *progs;
struct bpf_prog *orig;
if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
progs = &stab->progs;
} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) {
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
progs = &htab->progs;
} else {
return -EINVAL;
}
switch (type) {
case BPF_SK_MSG_VERDICT:
orig = xchg(&progs->bpf_tx_msg, prog);
break;
case BPF_SK_SKB_STREAM_PARSER:
orig = xchg(&progs->bpf_parse, prog);
break;
case BPF_SK_SKB_STREAM_VERDICT:
orig = xchg(&progs->bpf_verdict, prog);
break;
default:
return -EOPNOTSUPP;
}
if (orig)
bpf_prog_put(orig);
return 0;
}
int sockmap_get_from_fd(const union bpf_attr *attr, int type,
struct bpf_prog *prog)
{
int ufd = attr->target_fd;
struct bpf_map *map;
struct fd f;
int err;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
err = sock_map_prog(map, prog, attr->attach_type);
fdput(f);
return err;
}
static void *sock_map_lookup(struct bpf_map *map, void *key)
{
return ERR_PTR(-EOPNOTSUPP);
}
static int sock_map_update_elem(struct bpf_map *map,
void *key, void *value, u64 flags)
{
struct bpf_sock_ops_kern skops;
u32 fd = *(u32 *)value;
struct socket *socket;
int err;
socket = sockfd_lookup(fd, &err);
if (!socket)
return err;
skops.sk = socket->sk;
if (!skops.sk) {
fput(socket->file);
return -EINVAL;
}
/* ULPs are currently supported only for TCP sockets in ESTABLISHED
* state.
*/
if (skops.sk->sk_type != SOCK_STREAM ||
skops.sk->sk_protocol != IPPROTO_TCP ||
skops.sk->sk_state != TCP_ESTABLISHED) {
fput(socket->file);
return -EOPNOTSUPP;
}
lock_sock(skops.sk);
preempt_disable();
rcu_read_lock();
err = sock_map_ctx_update_elem(&skops, map, key, flags);
rcu_read_unlock();
preempt_enable();
release_sock(skops.sk);
fput(socket->file);
return err;
}
static void sock_map_release(struct bpf_map *map)
{
struct bpf_sock_progs *progs;
struct bpf_prog *orig;
if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
progs = &stab->progs;
} else {
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
progs = &htab->progs;
}
orig = xchg(&progs->bpf_parse, NULL);
if (orig)
bpf_prog_put(orig);
orig = xchg(&progs->bpf_verdict, NULL);
if (orig)
bpf_prog_put(orig);
orig = xchg(&progs->bpf_tx_msg, NULL);
if (orig)
bpf_prog_put(orig);
}
static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
{
struct bpf_htab *htab;
int i, err;
u64 cost;
if (!capable(CAP_NET_ADMIN))
return ERR_PTR(-EPERM);
/* check sanity of attributes */
if (attr->max_entries == 0 ||
attr->key_size == 0 ||
attr->value_size != 4 ||
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
return ERR_PTR(-EINVAL);
if (attr->key_size > MAX_BPF_STACK)
/* eBPF programs initialize keys on stack, so they cannot be
* larger than max stack size
*/
return ERR_PTR(-E2BIG);
htab = kzalloc(sizeof(*htab), GFP_USER);
if (!htab)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&htab->map, attr);
htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
htab->elem_size = sizeof(struct htab_elem) +
round_up(htab->map.key_size, 8);
err = -EINVAL;
if (htab->n_buckets == 0 ||
htab->n_buckets > U32_MAX / sizeof(struct bucket))
goto free_htab;
cost = (u64) htab->n_buckets * sizeof(struct bucket) +
(u64) htab->elem_size * htab->map.max_entries;
if (cost >= U32_MAX - PAGE_SIZE)
goto free_htab;
htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
err = bpf_map_precharge_memlock(htab->map.pages);
if (err)
goto free_htab;
err = -ENOMEM;
htab->buckets = bpf_map_area_alloc(
htab->n_buckets * sizeof(struct bucket),
htab->map.numa_node);
if (!htab->buckets)
goto free_htab;
for (i = 0; i < htab->n_buckets; i++) {
INIT_HLIST_HEAD(&htab->buckets[i].head);
raw_spin_lock_init(&htab->buckets[i].lock);
}
return &htab->map;
free_htab:
kfree(htab);
return ERR_PTR(err);
}
static void __bpf_htab_free(struct rcu_head *rcu)
{
struct bpf_htab *htab;
htab = container_of(rcu, struct bpf_htab, rcu);
bpf_map_area_free(htab->buckets);
kfree(htab);
}
static void sock_hash_free(struct bpf_map *map)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
int i;
synchronize_rcu();
/* At this point no update, lookup or delete operations can happen.
* However, be aware we can still get a socket state event updates,
* and data ready callabacks that reference the psock from sk_user_data
* Also psock worker threads are still in-flight. So smap_release_sock
* will only free the psock after cancel_sync on the worker threads
* and a grace period expire to ensure psock is really safe to remove.
*/
rcu_read_lock();
for (i = 0; i < htab->n_buckets; i++) {
struct bucket *b = __select_bucket(htab, i);
struct hlist_head *head;
struct hlist_node *n;
struct htab_elem *l;
raw_spin_lock_bh(&b->lock);
head = &b->head;
hlist_for_each_entry_safe(l, n, head, hash_node) {
struct sock *sock = l->sk;
struct smap_psock *psock;
hlist_del_rcu(&l->hash_node);
psock = smap_psock_sk(sock);
/* This check handles a racing sock event that can get
* the sk_callback_lock before this case but after xchg
* causing the refcnt to hit zero and sock user data
* (psock) to be null and queued for garbage collection.
*/
if (likely(psock)) {
smap_list_hash_remove(psock, l);
smap_release_sock(psock, sock);
}
free_htab_elem(htab, l);
}
raw_spin_unlock_bh(&b->lock);
}
rcu_read_unlock();
call_rcu(&htab->rcu, __bpf_htab_free);
}
static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab,
void *key, u32 key_size, u32 hash,
struct sock *sk,
struct htab_elem *old_elem)
{
struct htab_elem *l_new;
if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
if (!old_elem) {
atomic_dec(&htab->count);
return ERR_PTR(-E2BIG);
}
}
l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
htab->map.numa_node);
if (!l_new) {
atomic_dec(&htab->count);
return ERR_PTR(-ENOMEM);
}
memcpy(l_new->key, key, key_size);
l_new->sk = sk;
l_new->hash = hash;
return l_new;
}
static inline u32 htab_map_hash(const void *key, u32 key_len)
{
return jhash(key, key_len, 0);
}
static int sock_hash_get_next_key(struct bpf_map *map,
void *key, void *next_key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct htab_elem *l, *next_l;
struct hlist_head *h;
u32 hash, key_size;
int i = 0;
WARN_ON_ONCE(!rcu_read_lock_held());
key_size = map->key_size;
if (!key)
goto find_first_elem;
hash = htab_map_hash(key, key_size);
h = select_bucket(htab, hash);
l = lookup_elem_raw(h, hash, key, key_size);
if (!l)
goto find_first_elem;
next_l = hlist_entry_safe(
rcu_dereference_raw(hlist_next_rcu(&l->hash_node)),
struct htab_elem, hash_node);
if (next_l) {
memcpy(next_key, next_l->key, key_size);
return 0;
}
/* no more elements in this hash list, go to the next bucket */
i = hash & (htab->n_buckets - 1);
i++;
find_first_elem:
/* iterate over buckets */
for (; i < htab->n_buckets; i++) {
h = select_bucket(htab, i);
/* pick first element in the bucket */
next_l = hlist_entry_safe(
rcu_dereference_raw(hlist_first_rcu(h)),
struct htab_elem, hash_node);
if (next_l) {
/* if it's not empty, just return it */
memcpy(next_key, next_l->key, key_size);
return 0;
}
}
/* iterated over all buckets and all elements */
return -ENOENT;
}
static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops,
struct bpf_map *map,
void *key, u64 map_flags)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct bpf_sock_progs *progs = &htab->progs;
struct htab_elem *l_new = NULL, *l_old;
struct smap_psock_map_entry *e = NULL;
struct hlist_head *head;
struct smap_psock *psock;
u32 key_size, hash;
struct sock *sock;
struct bucket *b;
int err;
sock = skops->sk;
if (sock->sk_type != SOCK_STREAM ||
sock->sk_protocol != IPPROTO_TCP)
return -EOPNOTSUPP;
if (unlikely(map_flags > BPF_EXIST))
return -EINVAL;
e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
if (!e)
return -ENOMEM;
WARN_ON_ONCE(!rcu_read_lock_held());
key_size = map->key_size;
hash = htab_map_hash(key, key_size);
b = __select_bucket(htab, hash);
head = &b->head;
err = __sock_map_ctx_update_elem(map, progs, sock, key);
if (err)
goto err;
/* psock is valid here because otherwise above *ctx_update_elem would
* have thrown an error. It is safe to skip error check.
*/
psock = smap_psock_sk(sock);
raw_spin_lock_bh(&b->lock);
l_old = lookup_elem_raw(head, hash, key, key_size);
if (l_old && map_flags == BPF_NOEXIST) {
err = -EEXIST;
goto bucket_err;
}
if (!l_old && map_flags == BPF_EXIST) {
err = -ENOENT;
goto bucket_err;
}
l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old);
if (IS_ERR(l_new)) {
err = PTR_ERR(l_new);
goto bucket_err;
}
rcu_assign_pointer(e->hash_link, l_new);
e->map = map;
spin_lock_bh(&psock->maps_lock);
list_add_tail(&e->list, &psock->maps);
spin_unlock_bh(&psock->maps_lock);
/* add new element to the head of the list, so that
* concurrent search will find it before old elem
*/
hlist_add_head_rcu(&l_new->hash_node, head);
if (l_old) {
psock = smap_psock_sk(l_old->sk);
hlist_del_rcu(&l_old->hash_node);
smap_list_hash_remove(psock, l_old);
smap_release_sock(psock, l_old->sk);
free_htab_elem(htab, l_old);
}
raw_spin_unlock_bh(&b->lock);
return 0;
bucket_err:
smap_release_sock(psock, sock);
raw_spin_unlock_bh(&b->lock);
err:
kfree(e);
return err;
}
static int sock_hash_update_elem(struct bpf_map *map,
void *key, void *value, u64 flags)
{
struct bpf_sock_ops_kern skops;
u32 fd = *(u32 *)value;
struct socket *socket;
int err;
socket = sockfd_lookup(fd, &err);
if (!socket)
return err;
skops.sk = socket->sk;
if (!skops.sk) {
fput(socket->file);
return -EINVAL;
}
/* ULPs are currently supported only for TCP sockets in ESTABLISHED
* state.
*/
if (skops.sk->sk_type != SOCK_STREAM ||
skops.sk->sk_protocol != IPPROTO_TCP ||
skops.sk->sk_state != TCP_ESTABLISHED) {
fput(socket->file);
return -EOPNOTSUPP;
}
lock_sock(skops.sk);
preempt_disable();
rcu_read_lock();
err = sock_hash_ctx_update_elem(&skops, map, key, flags);
rcu_read_unlock();
preempt_enable();
release_sock(skops.sk);
fput(socket->file);
return err;
}
static int sock_hash_delete_elem(struct bpf_map *map, void *key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct hlist_head *head;
struct bucket *b;
struct htab_elem *l;
u32 hash, key_size;
int ret = -ENOENT;
key_size = map->key_size;
hash = htab_map_hash(key, key_size);
b = __select_bucket(htab, hash);
head = &b->head;
raw_spin_lock_bh(&b->lock);
l = lookup_elem_raw(head, hash, key, key_size);
if (l) {
struct sock *sock = l->sk;
struct smap_psock *psock;
hlist_del_rcu(&l->hash_node);
psock = smap_psock_sk(sock);
/* This check handles a racing sock event that can get the
* sk_callback_lock before this case but after xchg happens
* causing the refcnt to hit zero and sock user data (psock)
* to be null and queued for garbage collection.
*/
if (likely(psock)) {
smap_list_hash_remove(psock, l);
smap_release_sock(psock, sock);
}
free_htab_elem(htab, l);
ret = 0;
}
raw_spin_unlock_bh(&b->lock);
return ret;
}
struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct hlist_head *head;
struct htab_elem *l;
u32 key_size, hash;
struct bucket *b;
struct sock *sk;
key_size = map->key_size;
hash = htab_map_hash(key, key_size);
b = __select_bucket(htab, hash);
head = &b->head;
l = lookup_elem_raw(head, hash, key, key_size);
sk = l ? l->sk : NULL;
return sk;
}
const struct bpf_map_ops sock_map_ops = {
.map_alloc = sock_map_alloc,
.map_free = sock_map_free,
.map_lookup_elem = sock_map_lookup,
.map_get_next_key = sock_map_get_next_key,
.map_update_elem = sock_map_update_elem,
.map_delete_elem = sock_map_delete_elem,
.map_release_uref = sock_map_release,
.map_check_btf = map_check_no_btf,
};
const struct bpf_map_ops sock_hash_ops = {
.map_alloc = sock_hash_alloc,
.map_free = sock_hash_free,
.map_lookup_elem = sock_map_lookup,
.map_get_next_key = sock_hash_get_next_key,
.map_update_elem = sock_hash_update_elem,
.map_delete_elem = sock_hash_delete_elem,
.map_release_uref = sock_map_release,
.map_check_btf = map_check_no_btf,
};
static bool bpf_is_valid_sock_op(struct bpf_sock_ops_kern *ops)
{
return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
}
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
/* ULPs are currently supported only for TCP sockets in ESTABLISHED
* state. This checks that the sock ops triggering the update is
* one indicating we are (or will be soon) in an ESTABLISHED state.
*/
if (!bpf_is_valid_sock_op(bpf_sock))
return -EOPNOTSUPP;
return sock_map_ctx_update_elem(bpf_sock, map, key, flags);
}
const struct bpf_func_proto bpf_sock_map_update_proto = {
.func = bpf_sock_map_update,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
if (!bpf_is_valid_sock_op(bpf_sock))
return -EOPNOTSUPP;
return sock_hash_ctx_update_elem(bpf_sock, map, key, flags);
}
const struct bpf_func_proto bpf_sock_hash_update_proto = {
.func = bpf_sock_hash_update,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
kernel/bpf/syscall.c
View file @ 604326b4
......@@ -1664,7 +1664,7 @@ static int bpf_prog_attach(const union bpf_attr *attr)
switch (ptype) {
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
ret = sockmap_get_from_fd(attr, ptype, prog);
ret = sock_map_get_from_fd(attr, prog);
break;
case BPF_PROG_TYPE_LIRC_MODE2:
ret = lirc_prog_attach(attr, prog);
......@@ -1718,10 +1718,10 @@ static int bpf_prog_detach(const union bpf_attr *attr)
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
case BPF_SK_MSG_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, NULL);
return sock_map_get_from_fd(attr, NULL);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, NULL);
return sock_map_get_from_fd(attr, NULL);
case BPF_LIRC_MODE2:
return lirc_prog_detach(attr);
case BPF_FLOW_DISSECTOR:
......
net/Kconfig
View file @ 604326b4
......@@ -300,8 +300,11 @@ config BPF_JIT
config BPF_STREAM_PARSER
bool "enable BPF STREAM_PARSER"
depends on INET
depends on BPF_SYSCALL
depends on CGROUP_BPF
select STREAM_PARSER
select NET_SOCK_MSG
---help---
Enabling this allows a stream parser to be used with
BPF_MAP_TYPE_SOCKMAP.
......@@ -413,6 +416,14 @@ config GRO_CELLS
config SOCK_VALIDATE_XMIT
bool
config NET_SOCK_MSG
bool
default n
help
The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or
ULPs (upper layer modules, e.g. TLS) to process L7 application data
with the help of BPF programs.
config NET_DEVLINK
tristate "Network physical/parent device Netlink interface"
help
......
net/core/Makefile
View file @ 604326b4
......@@ -16,6 +16,7 @@ obj-y += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \
obj-y += net-sysfs.o
obj-$(CONFIG_PAGE_POOL) += page_pool.o
obj-$(CONFIG_PROC_FS) += net-procfs.o
obj-$(CONFIG_NET_SOCK_MSG) += skmsg.o
obj-$(CONFIG_NET_PKTGEN) += pktgen.o
obj-$(CONFIG_NETPOLL) += netpoll.o
obj-$(CONFIG_FIB_RULES) += fib_rules.o
......@@ -27,6 +28,7 @@ obj-$(CONFIG_CGROUP_NET_PRIO) += netprio_cgroup.o
obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o
obj-$(CONFIG_LWTUNNEL) += lwtunnel.o
obj-$(CONFIG_LWTUNNEL_BPF) += lwt_bpf.o
obj-$(CONFIG_BPF_STREAM_PARSER) += sock_map.o
obj-$(CONFIG_DST_CACHE) += dst_cache.o
obj-$(CONFIG_HWBM) += hwbm.o
obj-$(CONFIG_NET_DEVLINK) += devlink.o
......
net/core/filter.c
View file @ 604326b4
......@@ -38,6 +38,7 @@
#include <net/protocol.h>
#include <net/netlink.h>
#include <linux/skbuff.h>
#include <linux/skmsg.h>
#include <net/sock.h>
#include <net/flow_dissector.h>
#include <linux/errno.h>
......@@ -2142,123 +2143,7 @@ static const struct bpf_func_proto bpf_redirect_proto = {
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
struct bpf_map *, map, void *, key, u64, flags)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
/* If user passes invalid input drop the packet. */
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
tcb->bpf.flags = flags;
tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key);
if (!tcb->bpf.sk_redir)
return SK_DROP;
return SK_PASS;
}
static const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
.func = bpf_sk_redirect_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
struct bpf_map *, map, u32, key, u64, flags)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
/* If user passes invalid input drop the packet. */
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
tcb->bpf.flags = flags;
tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key);
if (!tcb->bpf.sk_redir)
return SK_DROP;
return SK_PASS;
}
struct sock *do_sk_redirect_map(struct sk_buff *skb)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
return tcb->bpf.sk_redir;
}
static const struct bpf_func_proto bpf_sk_redirect_map_proto = {
.func = bpf_sk_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg_buff *, msg,
struct bpf_map *, map, void *, key, u64, flags)
{
/* If user passes invalid input drop the packet. */
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
msg->flags = flags;
msg->sk_redir = __sock_hash_lookup_elem(map, key);
if (!msg->sk_redir)
return SK_DROP;
return SK_PASS;
}
static const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
.func = bpf_msg_redirect_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg_buff *, msg,
struct bpf_map *, map, u32, key, u64, flags)
{
/* If user passes invalid input drop the packet. */
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
msg->flags = flags;
msg->sk_redir = __sock_map_lookup_elem(map, key);
if (!msg->sk_redir)
return SK_DROP;
return SK_PASS;
}
struct sock *do_msg_redirect_map(struct sk_msg_buff *msg)
{
return msg->sk_redir;
}
static const struct bpf_func_proto bpf_msg_redirect_map_proto = {
.func = bpf_msg_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_2(bpf_msg_apply_bytes, struct sk_msg_buff *, msg, u32, bytes)
BPF_CALL_2(bpf_msg_apply_bytes, struct sk_msg *, msg, u32, bytes)
{
msg->apply_bytes = bytes;
return 0;
......@@ -2272,7 +2157,7 @@ static const struct bpf_func_proto bpf_msg_apply_bytes_proto = {
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_2(bpf_msg_cork_bytes, struct sk_msg_buff *, msg, u32, bytes)
BPF_CALL_2(bpf_msg_cork_bytes, struct sk_msg *, msg, u32, bytes)
{
msg->cork_bytes = bytes;
return 0;
......@@ -2286,45 +2171,37 @@ static const struct bpf_func_proto bpf_msg_cork_bytes_proto = {
.arg2_type = ARG_ANYTHING,
};
#define sk_msg_iter_var(var) \
do { \
var++; \
if (var == MAX_SKB_FRAGS) \
var = 0; \
} while (0)
BPF_CALL_4(bpf_msg_pull_data,
struct sk_msg_buff *, msg, u32, start, u32, end, u64, flags)
BPF_CALL_4(bpf_msg_pull_data, struct sk_msg *, msg, u32, start,
u32, end, u64, flags)
{
unsigned int len = 0, offset = 0, copy = 0, poffset = 0;
int bytes = end - start, bytes_sg_total;
struct scatterlist *sg = msg->sg_data;
int first_sg, last_sg, i, shift;
unsigned char *p, *to, *from;
u32 len = 0, offset = 0, copy = 0, poffset = 0, bytes = end - start;
u32 first_sge, last_sge, i, shift, bytes_sg_total;
struct scatterlist *sge;
u8 *raw, *to, *from;
struct page *page;
if (unlikely(flags || end <= start))
return -EINVAL;
/* First find the starting scatterlist element */
i = msg->sg_start;
i = msg->sg.start;
do {
len = sg[i].length;
len = sk_msg_elem(msg, i)->length;
if (start < offset + len)
break;
offset += len;
sk_msg_iter_var(i);
} while (i != msg->sg_end);
sk_msg_iter_var_next(i);
} while (i != msg->sg.end);
if (unlikely(start >= offset + len))
return -EINVAL;
first_sg = i;
first_sge = i;
/* The start may point into the sg element so we need to also
* account for the headroom.
*/
bytes_sg_total = start - offset + bytes;
if (!msg->sg_copy[i] && bytes_sg_total <= len)
if (!msg->sg.copy[i] && bytes_sg_total <= len)
goto out;
/* At this point we need to linearize multiple scatterlist
......@@ -2338,12 +2215,12 @@ BPF_CALL_4(bpf_msg_pull_data,
* will copy the entire sg entry.
*/
do {
copy += sg[i].length;
sk_msg_iter_var(i);
copy += sk_msg_elem(msg, i)->length;
sk_msg_iter_var_next(i);
if (bytes_sg_total <= copy)
break;
} while (i != msg->sg_end);
last_sg = i;
} while (i != msg->sg.end);
last_sge = i;
if (unlikely(bytes_sg_total > copy))
return -EINVAL;
......@@ -2352,63 +2229,61 @@ BPF_CALL_4(bpf_msg_pull_data,
get_order(copy));
if (unlikely(!page))
return -ENOMEM;
p = page_address(page);
i = first_sg;
raw = page_address(page);
i = first_sge;
do {
from = sg_virt(&sg[i]);
len = sg[i].length;
to = p + poffset;
sge = sk_msg_elem(msg, i);
from = sg_virt(sge);
len = sge->length;
to = raw + poffset;
memcpy(to, from, len);
poffset += len;
sg[i].length = 0;
put_page(sg_page(&sg[i]));
sge->length = 0;
put_page(sg_page(sge));
sk_msg_iter_var(i);
} while (i != last_sg);
sk_msg_iter_var_next(i);
} while (i != last_sge);
sg[first_sg].length = copy;
sg_set_page(&sg[first_sg], page, copy, 0);
sg_set_page(&msg->sg.data[first_sge], page, copy, 0);
/* To repair sg ring we need to shift entries. If we only
* had a single entry though we can just replace it and
* be done. Otherwise walk the ring and shift the entries.
*/
WARN_ON_ONCE(last_sg == first_sg);
shift = last_sg > first_sg ?
last_sg - first_sg - 1 :
MAX_SKB_FRAGS - first_sg + last_sg - 1;
WARN_ON_ONCE(last_sge == first_sge);
shift = last_sge > first_sge ?
last_sge - first_sge - 1 :
MAX_SKB_FRAGS - first_sge + last_sge - 1;
if (!shift)
goto out;
i = first_sg;
sk_msg_iter_var(i);
i = first_sge;
sk_msg_iter_var_next(i);
do {
int move_from;
u32 move_from;
if (i + shift >= MAX_SKB_FRAGS)
move_from = i + shift - MAX_SKB_FRAGS;
if (i + shift >= MAX_MSG_FRAGS)
move_from = i + shift - MAX_MSG_FRAGS;
else
move_from = i + shift;
if (move_from == msg->sg_end)
if (move_from == msg->sg.end)
break;
sg[i] = sg[move_from];
sg[move_from].length = 0;
sg[move_from].page_link = 0;
sg[move_from].offset = 0;
sk_msg_iter_var(i);
msg->sg.data[i] = msg->sg.data[move_from];
msg->sg.data[move_from].length = 0;
msg->sg.data[move_from].page_link = 0;
msg->sg.data[move_from].offset = 0;
sk_msg_iter_var_next(i);
} while (1);
msg->sg_end -= shift;
if (msg->sg_end < 0)
msg->sg_end += MAX_SKB_FRAGS;
msg->sg.end = msg->sg.end - shift > msg->sg.end ?
msg->sg.end - shift + MAX_MSG_FRAGS :
msg->sg.end - shift;
out:
msg->data = sg_virt(&sg[first_sg]) + start - offset;
msg->data = sg_virt(&msg->sg.data[first_sge]) + start - offset;
msg->data_end = msg->data + bytes;
return 0;
}
......@@ -5203,6 +5078,9 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
}
const struct bpf_func_proto bpf_sock_map_update_proto __weak;
const struct bpf_func_proto bpf_sock_hash_update_proto __weak;
static const struct bpf_func_proto *
sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
......@@ -5226,6 +5104,9 @@ sock_ops_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
}
const struct bpf_func_proto bpf_msg_redirect_map_proto __weak;
const struct bpf_func_proto bpf_msg_redirect_hash_proto __weak;
static const struct bpf_func_proto *
sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
......@@ -5247,6 +5128,9 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
}
}
const struct bpf_func_proto bpf_sk_redirect_map_proto __weak;
const struct bpf_func_proto bpf_sk_redirect_hash_proto __weak;
static const struct bpf_func_proto *
sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
......@@ -7001,22 +6885,22 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
switch (si->off) {
case offsetof(struct sk_msg_md, data):
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg_buff, data),
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg, data),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, data));
offsetof(struct sk_msg, data));
break;
case offsetof(struct sk_msg_md, data_end):
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg_buff, data_end),
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_msg, data_end),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, data_end));
offsetof(struct sk_msg, data_end));
break;
case offsetof(struct sk_msg_md, family):
BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_family) != 2);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg,
offsetof(struct sock_common, skc_family));
break;
......@@ -7025,9 +6909,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_daddr) != 4);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
offsetof(struct sock_common, skc_daddr));
break;
......@@ -7037,9 +6921,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
skc_rcv_saddr) != 4);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
offsetof(struct sock_common,
skc_rcv_saddr));
......@@ -7054,9 +6938,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
off = si->off;
off -= offsetof(struct sk_msg_md, remote_ip6[0]);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
offsetof(struct sock_common,
skc_v6_daddr.s6_addr32[0]) +
......@@ -7075,9 +6959,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
off = si->off;
off -= offsetof(struct sk_msg_md, local_ip6[0]);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
offsetof(struct sock_common,
skc_v6_rcv_saddr.s6_addr32[0]) +
......@@ -7091,9 +6975,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_dport) != 2);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg,
offsetof(struct sock_common, skc_dport));
#ifndef __BIG_ENDIAN_BITFIELD
......@@ -7105,9 +6989,9 @@ static u32 sk_msg_convert_ctx_access(enum bpf_access_type type,
BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_num) != 2);
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
struct sk_msg_buff, sk),
struct sk_msg, sk),
si->dst_reg, si->src_reg,
offsetof(struct sk_msg_buff, sk));
offsetof(struct sk_msg, sk));
*insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg,
offsetof(struct sock_common, skc_num));
break;
......
net/core/skmsg.c 0 → 100644
View file @ 604326b4
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
#include <linux/skmsg.h>
#include <linux/skbuff.h>
#include <linux/scatterlist.h>
#include <net/sock.h>
#include <net/tcp.h>
static bool sk_msg_try_coalesce_ok(struct sk_msg *msg, int elem_first_coalesce)
{
if (msg->sg.end > msg->sg.start &&
elem_first_coalesce < msg->sg.end)
return true;
if (msg->sg.end < msg->sg.start &&
(elem_first_coalesce > msg->sg.start ||
elem_first_coalesce < msg->sg.end))
return true;
return false;
}
int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
int elem_first_coalesce)
{
struct page_frag *pfrag = sk_page_frag(sk);
int ret = 0;
len -= msg->sg.size;
while (len > 0) {
struct scatterlist *sge;
u32 orig_offset;
int use, i;
if (!sk_page_frag_refill(sk, pfrag))
return -ENOMEM;
orig_offset = pfrag->offset;
use = min_t(int, len, pfrag->size - orig_offset);
if (!sk_wmem_schedule(sk, use))
return -ENOMEM;
i = msg->sg.end;
sk_msg_iter_var_prev(i);
sge = &msg->sg.data[i];
if (sk_msg_try_coalesce_ok(msg, elem_first_coalesce) &&
sg_page(sge) == pfrag->page &&
sge->offset + sge->length == orig_offset) {
sge->length += use;
} else {
if (sk_msg_full(msg)) {
ret = -ENOSPC;
break;
}
sge = &msg->sg.data[msg->sg.end];
sg_unmark_end(sge);
sg_set_page(sge, pfrag->page, use, orig_offset);
get_page(pfrag->page);
sk_msg_iter_next(msg, end);
}
sk_mem_charge(sk, use);
msg->sg.size += use;
pfrag->offset += use;
len -= use;
}
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_alloc);
void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes)
{
int i = msg->sg.start;
do {
struct scatterlist *sge = sk_msg_elem(msg, i);
if (bytes < sge->length) {
sge->length -= bytes;
sge->offset += bytes;
sk_mem_uncharge(sk, bytes);
break;
}
sk_mem_uncharge(sk, sge->length);
bytes -= sge->length;
sge->length = 0;
sge->offset = 0;
sk_msg_iter_var_next(i);
} while (bytes && i != msg->sg.end);
msg->sg.start = i;
}
EXPORT_SYMBOL_GPL(sk_msg_return_zero);
void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes)
{
int i = msg->sg.start;
do {
struct scatterlist *sge = &msg->sg.data[i];
int uncharge = (bytes < sge->length) ? bytes : sge->length;
sk_mem_uncharge(sk, uncharge);
bytes -= uncharge;
sk_msg_iter_var_next(i);
} while (i != msg->sg.end);
}
EXPORT_SYMBOL_GPL(sk_msg_return);
static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i,
bool charge)
{
struct scatterlist *sge = sk_msg_elem(msg, i);
u32 len = sge->length;
if (charge)
sk_mem_uncharge(sk, len);
if (!msg->skb)
put_page(sg_page(sge));
memset(sge, 0, sizeof(*sge));
return len;
}
static int __sk_msg_free(struct sock *sk, struct sk_msg *msg, u32 i,
bool charge)
{
struct scatterlist *sge = sk_msg_elem(msg, i);
int freed = 0;
while (msg->sg.size) {
msg->sg.size -= sge->length;
freed += sk_msg_free_elem(sk, msg, i, charge);
sk_msg_iter_var_next(i);
sk_msg_check_to_free(msg, i, msg->sg.size);
sge = sk_msg_elem(msg, i);
}
if (msg->skb)
consume_skb(msg->skb);
sk_msg_init(msg);
return freed;
}
int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg)
{
return __sk_msg_free(sk, msg, msg->sg.start, false);
}
EXPORT_SYMBOL_GPL(sk_msg_free_nocharge);
int sk_msg_free(struct sock *sk, struct sk_msg *msg)
{
return __sk_msg_free(sk, msg, msg->sg.start, true);
}
EXPORT_SYMBOL_GPL(sk_msg_free);
static void __sk_msg_free_partial(struct sock *sk, struct sk_msg *msg,
u32 bytes, bool charge)
{
struct scatterlist *sge;
u32 i = msg->sg.start;
while (bytes) {
sge = sk_msg_elem(msg, i);
if (!sge->length)
break;
if (bytes < sge->length) {
if (charge)
sk_mem_uncharge(sk, bytes);
sge->length -= bytes;
sge->offset += bytes;
msg->sg.size -= bytes;
break;
}
msg->sg.size -= sge->length;
bytes -= sge->length;
sk_msg_free_elem(sk, msg, i, charge);
sk_msg_iter_var_next(i);
sk_msg_check_to_free(msg, i, bytes);
}
msg->sg.start = i;
}
void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes)
{
__sk_msg_free_partial(sk, msg, bytes, true);
}
EXPORT_SYMBOL_GPL(sk_msg_free_partial);
void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
u32 bytes)
{
__sk_msg_free_partial(sk, msg, bytes, false);
}
void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len)
{
int trim = msg->sg.size - len;
u32 i = msg->sg.end;
if (trim <= 0) {
WARN_ON(trim < 0);
return;
}
sk_msg_iter_var_prev(i);
msg->sg.size = len;
while (msg->sg.data[i].length &&
trim >= msg->sg.data[i].length) {
trim -= msg->sg.data[i].length;
sk_msg_free_elem(sk, msg, i, true);
sk_msg_iter_var_prev(i);
if (!trim)
goto out;
}
msg->sg.data[i].length -= trim;
sk_mem_uncharge(sk, trim);
out:
/* If we trim data before curr pointer update copybreak and current
* so that any future copy operations start at new copy location.
* However trimed data that has not yet been used in a copy op
* does not require an update.
*/
if (msg->sg.curr >= i) {
msg->sg.curr = i;
msg->sg.copybreak = msg->sg.data[i].length;
}
sk_msg_iter_var_next(i);
msg->sg.end = i;
}
EXPORT_SYMBOL_GPL(sk_msg_trim);
int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes)
{
int i, maxpages, ret = 0, num_elems = sk_msg_elem_used(msg);
const int to_max_pages = MAX_MSG_FRAGS;
struct page *pages[MAX_MSG_FRAGS];
ssize_t orig, copied, use, offset;
orig = msg->sg.size;
while (bytes > 0) {
i = 0;
maxpages = to_max_pages - num_elems;
if (maxpages == 0) {
ret = -EFAULT;
goto out;
}
copied = iov_iter_get_pages(from, pages, bytes, maxpages,
&offset);
if (copied <= 0) {
ret = -EFAULT;
goto out;
}
iov_iter_advance(from, copied);
bytes -= copied;
msg->sg.size += copied;
while (copied) {
use = min_t(int, copied, PAGE_SIZE - offset);
sg_set_page(&msg->sg.data[msg->sg.end],
pages[i], use, offset);
sg_unmark_end(&msg->sg.data[msg->sg.end]);
sk_mem_charge(sk, use);
offset = 0;
copied -= use;
sk_msg_iter_next(msg, end);
num_elems++;
i++;
}
/* When zerocopy is mixed with sk_msg_*copy* operations we
* may have a copybreak set in this case clear and prefer
* zerocopy remainder when possible.
*/
msg->sg.copybreak = 0;
msg->sg.curr = msg->sg.end;
}
out:
/* Revert iov_iter updates, msg will need to use 'trim' later if it
* also needs to be cleared.
*/
if (ret)
iov_iter_revert(from, msg->sg.size - orig);
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_zerocopy_from_iter);
int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
struct sk_msg *msg, u32 bytes)
{
int ret = -ENOSPC, i = msg->sg.curr;
struct scatterlist *sge;
u32 copy, buf_size;
void *to;
do {
sge = sk_msg_elem(msg, i);
/* This is possible if a trim operation shrunk the buffer */
if (msg->sg.copybreak >= sge->length) {
msg->sg.copybreak = 0;
sk_msg_iter_var_next(i);
if (i == msg->sg.end)
break;
sge = sk_msg_elem(msg, i);
}
buf_size = sge->length - msg->sg.copybreak;
copy = (buf_size > bytes) ? bytes : buf_size;
to = sg_virt(sge) + msg->sg.copybreak;
msg->sg.copybreak += copy;
if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
ret = copy_from_iter_nocache(to, copy, from);
else
ret = copy_from_iter(to, copy, from);
if (ret != copy) {
ret = -EFAULT;
goto out;
}
bytes -= copy;
if (!bytes)
break;
msg->sg.copybreak = 0;
sk_msg_iter_var_next(i);
} while (i != msg->sg.end);
out:
msg->sg.curr = i;
return ret;
}
EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb)
{
struct sock *sk = psock->sk;
int copied = 0, num_sge;
struct sk_msg *msg;
msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC);
if (unlikely(!msg))
return -EAGAIN;
if (!sk_rmem_schedule(sk, skb, skb->len)) {
kfree(msg);
return -EAGAIN;
}
sk_msg_init(msg);
num_sge = skb_to_sgvec(skb, msg->sg.data, 0, skb->len);
if (unlikely(num_sge < 0)) {
kfree(msg);
return num_sge;
}
sk_mem_charge(sk, skb->len);
copied = skb->len;
msg->sg.start = 0;
msg->sg.end = num_sge == MAX_MSG_FRAGS ? 0 : num_sge;
msg->skb = skb;
sk_psock_queue_msg(psock, msg);
sk->sk_data_ready(sk);
return copied;
}
static int sk_psock_handle_skb(struct sk_psock *psock, struct sk_buff *skb,
u32 off, u32 len, bool ingress)
{
if (ingress)
return sk_psock_skb_ingress(psock, skb);
else
return skb_send_sock_locked(psock->sk, skb, off, len);
}
static void sk_psock_backlog(struct work_struct *work)
{
struct sk_psock *psock = container_of(work, struct sk_psock, work);
struct sk_psock_work_state *state = &psock->work_state;
struct sk_buff *skb;
bool ingress;
u32 len, off;
int ret;
/* Lock sock to avoid losing sk_socket during loop. */
lock_sock(psock->sk);
if (state->skb) {
skb = state->skb;
len = state->len;
off = state->off;
state->skb = NULL;
goto start;
}
while ((skb = skb_dequeue(&psock->ingress_skb))) {
len = skb->len;
off = 0;
start:
ingress = tcp_skb_bpf_ingress(skb);
do {
ret = -EIO;
if (likely(psock->sk->sk_socket))
ret = sk_psock_handle_skb(psock, skb, off,
len, ingress);
if (ret <= 0) {
if (ret == -EAGAIN) {
state->skb = skb;
state->len = len;
state->off = off;
goto end;
}
/* Hard errors break pipe and stop xmit. */
sk_psock_report_error(psock, ret ? -ret : EPIPE);
sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
kfree_skb(skb);
goto end;
}
off += ret;
len -= ret;
} while (len);
if (!ingress)
kfree_skb(skb);
}
end:
release_sock(psock->sk);
}
struct sk_psock *sk_psock_init(struct sock *sk, int node)
{
struct sk_psock *psock = kzalloc_node(sizeof(*psock),
GFP_ATOMIC | __GFP_NOWARN,
node);
if (!psock)
return NULL;
psock->sk = sk;
psock->eval = __SK_NONE;
INIT_LIST_HEAD(&psock->link);
spin_lock_init(&psock->link_lock);
INIT_WORK(&psock->work, sk_psock_backlog);
INIT_LIST_HEAD(&psock->ingress_msg);
skb_queue_head_init(&psock->ingress_skb);
sk_psock_set_state(psock, SK_PSOCK_TX_ENABLED);
refcount_set(&psock->refcnt, 1);
rcu_assign_sk_user_data(sk, psock);
sock_hold(sk);
return psock;
}
EXPORT_SYMBOL_GPL(sk_psock_init);
struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock)
{
struct sk_psock_link *link;
spin_lock_bh(&psock->link_lock);
link = list_first_entry_or_null(&psock->link, struct sk_psock_link,
list);
if (link)
list_del(&link->list);
spin_unlock_bh(&psock->link_lock);
return link;
}
void __sk_psock_purge_ingress_msg(struct sk_psock *psock)
{
struct sk_msg *msg, *tmp;
list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) {
list_del(&msg->list);
sk_msg_free(psock->sk, msg);
kfree(msg);
}
}
static void sk_psock_zap_ingress(struct sk_psock *psock)
{
__skb_queue_purge(&psock->ingress_skb);
__sk_psock_purge_ingress_msg(psock);
}
static void sk_psock_link_destroy(struct sk_psock *psock)
{
struct sk_psock_link *link, *tmp;
list_for_each_entry_safe(link, tmp, &psock->link, list) {
list_del(&link->list);
sk_psock_free_link(link);
}
}
static void sk_psock_destroy_deferred(struct work_struct *gc)
{
struct sk_psock *psock = container_of(gc, struct sk_psock, gc);
/* No sk_callback_lock since already detached. */
if (psock->parser.enabled)
strp_done(&psock->parser.strp);
cancel_work_sync(&psock->work);
psock_progs_drop(&psock->progs);
sk_psock_link_destroy(psock);
sk_psock_cork_free(psock);
sk_psock_zap_ingress(psock);
if (psock->sk_redir)
sock_put(psock->sk_redir);
sock_put(psock->sk);
kfree(psock);
}
void sk_psock_destroy(struct rcu_head *rcu)
{
struct sk_psock *psock = container_of(rcu, struct sk_psock, rcu);
INIT_WORK(&psock->gc, sk_psock_destroy_deferred);
schedule_work(&psock->gc);
}
EXPORT_SYMBOL_GPL(sk_psock_destroy);
void sk_psock_drop(struct sock *sk, struct sk_psock *psock)
{
rcu_assign_sk_user_data(sk, NULL);
sk_psock_cork_free(psock);
sk_psock_restore_proto(sk, psock);
write_lock_bh(&sk->sk_callback_lock);
if (psock->progs.skb_parser)
sk_psock_stop_strp(sk, psock);
write_unlock_bh(&sk->sk_callback_lock);
sk_psock_clear_state(psock, SK_PSOCK_TX_ENABLED);
call_rcu_sched(&psock->rcu, sk_psock_destroy);
}
EXPORT_SYMBOL_GPL(sk_psock_drop);
static int sk_psock_map_verd(int verdict, bool redir)
{
switch (verdict) {
case SK_PASS:
return redir ? __SK_REDIRECT : __SK_PASS;
case SK_DROP:
default:
break;
}
return __SK_DROP;
}
int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg)
{
struct bpf_prog *prog;
int ret;
preempt_disable();
rcu_read_lock();
prog = READ_ONCE(psock->progs.msg_parser);
if (unlikely(!prog)) {
ret = __SK_PASS;
goto out;
}
sk_msg_compute_data_pointers(msg);
msg->sk = sk;
ret = BPF_PROG_RUN(prog, msg);
ret = sk_psock_map_verd(ret, msg->sk_redir);
psock->apply_bytes = msg->apply_bytes;
if (ret == __SK_REDIRECT) {
if (psock->sk_redir)
sock_put(psock->sk_redir);
psock->sk_redir = msg->sk_redir;
if (!psock->sk_redir) {
ret = __SK_DROP;
goto out;
}
sock_hold(psock->sk_redir);
}
out:
rcu_read_unlock();
preempt_enable();
return ret;
}
EXPORT_SYMBOL_GPL(sk_psock_msg_verdict);
static int sk_psock_bpf_run(struct sk_psock *psock, struct bpf_prog *prog,
struct sk_buff *skb)
{
int ret;
skb->sk = psock->sk;
bpf_compute_data_end_sk_skb(skb);
preempt_disable();
ret = BPF_PROG_RUN(prog, skb);
preempt_enable();
/* strparser clones the skb before handing it to a upper layer,
* meaning skb_orphan has been called. We NULL sk on the way out
* to ensure we don't trigger a BUG_ON() in skb/sk operations
* later and because we are not charging the memory of this skb
* to any socket yet.
*/
skb->sk = NULL;
return ret;
}
static struct sk_psock *sk_psock_from_strp(struct strparser *strp)
{
struct sk_psock_parser *parser;
parser = container_of(strp, struct sk_psock_parser, strp);
return container_of(parser, struct sk_psock, parser);
}
static void sk_psock_verdict_apply(struct sk_psock *psock,
struct sk_buff *skb, int verdict)
{
struct sk_psock *psock_other;
struct sock *sk_other;
bool ingress;
switch (verdict) {
case __SK_REDIRECT:
sk_other = tcp_skb_bpf_redirect_fetch(skb);
if (unlikely(!sk_other))
goto out_free;
psock_other = sk_psock(sk_other);
if (!psock_other || sock_flag(sk_other, SOCK_DEAD) ||
!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED))
goto out_free;
ingress = tcp_skb_bpf_ingress(skb);
if ((!ingress && sock_writeable(sk_other)) ||
(ingress &&
atomic_read(&sk_other->sk_rmem_alloc) <=
sk_other->sk_rcvbuf)) {
if (!ingress)
skb_set_owner_w(skb, sk_other);
skb_queue_tail(&psock_other->ingress_skb, skb);
schedule_work(&psock_other->work);
break;
}
/* fall-through */
case __SK_DROP:
/* fall-through */
default:
out_free:
kfree_skb(skb);
}
}
static void sk_psock_strp_read(struct strparser *strp, struct sk_buff *skb)
{
struct sk_psock *psock = sk_psock_from_strp(strp);
struct bpf_prog *prog;
int ret = __SK_DROP;
rcu_read_lock();
prog = READ_ONCE(psock->progs.skb_verdict);
if (likely(prog)) {
skb_orphan(skb);
tcp_skb_bpf_redirect_clear(skb);
ret = sk_psock_bpf_run(psock, prog, skb);
ret = sk_psock_map_verd(ret, tcp_skb_bpf_redirect_fetch(skb));
}
rcu_read_unlock();
sk_psock_verdict_apply(psock, skb, ret);
}
static int sk_psock_strp_read_done(struct strparser *strp, int err)
{
return err;
}
static int sk_psock_strp_parse(struct strparser *strp, struct sk_buff *skb)
{
struct sk_psock *psock = sk_psock_from_strp(strp);
struct bpf_prog *prog;
int ret = skb->len;
rcu_read_lock();
prog = READ_ONCE(psock->progs.skb_parser);
if (likely(prog))
ret = sk_psock_bpf_run(psock, prog, skb);
rcu_read_unlock();
return ret;
}
/* Called with socket lock held. */
static void sk_psock_data_ready(struct sock *sk)
{
struct sk_psock *psock;
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock)) {
write_lock_bh(&sk->sk_callback_lock);
strp_data_ready(&psock->parser.strp);
write_unlock_bh(&sk->sk_callback_lock);
}
rcu_read_unlock();
}
static void sk_psock_write_space(struct sock *sk)
{
struct sk_psock *psock;
void (*write_space)(struct sock *sk);
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock && sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)))
schedule_work(&psock->work);
write_space = psock->saved_write_space;
rcu_read_unlock();
write_space(sk);
}
int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
{
static const struct strp_callbacks cb = {
.rcv_msg = sk_psock_strp_read,
.read_sock_done = sk_psock_strp_read_done,
.parse_msg = sk_psock_strp_parse,
};
psock->parser.enabled = false;
return strp_init(&psock->parser.strp, sk, &cb);
}
void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
{
struct sk_psock_parser *parser = &psock->parser;
if (parser->enabled)
return;
parser->saved_data_ready = sk->sk_data_ready;
sk->sk_data_ready = sk_psock_data_ready;
sk->sk_write_space = sk_psock_write_space;
parser->enabled = true;
}
void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
{
struct sk_psock_parser *parser = &psock->parser;
if (!parser->enabled)
return;
sk->sk_data_ready = parser->saved_data_ready;
parser->saved_data_ready = NULL;
strp_stop(&parser->strp);
parser->enabled = false;
}
net/core/sock_map.c 0 → 100644
View file @ 604326b4
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
#include <linux/bpf.h>
#include <linux/filter.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/net.h>
#include <linux/workqueue.h>
#include <linux/skmsg.h>
#include <linux/list.h>
#include <linux/jhash.h>
struct bpf_stab {
struct bpf_map map;
struct sock **sks;
struct sk_psock_progs progs;
raw_spinlock_t lock;
};
#define SOCK_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
{
struct bpf_stab *stab;
u64 cost;
int err;
if (!capable(CAP_NET_ADMIN))
return ERR_PTR(-EPERM);
if (attr->max_entries == 0 ||
attr->key_size != 4 ||
attr->value_size != 4 ||
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
return ERR_PTR(-EINVAL);
stab = kzalloc(sizeof(*stab), GFP_USER);
if (!stab)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&stab->map, attr);
raw_spin_lock_init(&stab->lock);
/* Make sure page count doesn't overflow. */
cost = (u64) stab->map.max_entries * sizeof(struct sock *);
if (cost >= U32_MAX - PAGE_SIZE) {
err = -EINVAL;
goto free_stab;
}
stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
err = bpf_map_precharge_memlock(stab->map.pages);
if (err)
goto free_stab;
stab->sks = bpf_map_area_alloc(stab->map.max_entries *
sizeof(struct sock *),
stab->map.numa_node);
if (stab->sks)
return &stab->map;
err = -ENOMEM;
free_stab:
kfree(stab);
return ERR_PTR(err);
}
int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
{
u32 ufd = attr->target_fd;
struct bpf_map *map;
struct fd f;
int ret;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
ret = sock_map_prog_update(map, prog, attr->attach_type);
fdput(f);
return ret;
}
static void sock_map_sk_acquire(struct sock *sk)
__acquires(&sk->sk_lock.slock)
{
lock_sock(sk);
preempt_disable();
rcu_read_lock();
}
static void sock_map_sk_release(struct sock *sk)
__releases(&sk->sk_lock.slock)
{
rcu_read_unlock();
preempt_enable();
release_sock(sk);
}
static void sock_map_add_link(struct sk_psock *psock,
struct sk_psock_link *link,
struct bpf_map *map, void *link_raw)
{
link->link_raw = link_raw;
link->map = map;
spin_lock_bh(&psock->link_lock);
list_add_tail(&link->list, &psock->link);
spin_unlock_bh(&psock->link_lock);
}
static void sock_map_del_link(struct sock *sk,
struct sk_psock *psock, void *link_raw)
{
struct sk_psock_link *link, *tmp;
bool strp_stop = false;
spin_lock_bh(&psock->link_lock);
list_for_each_entry_safe(link, tmp, &psock->link, list) {
if (link->link_raw == link_raw) {
struct bpf_map *map = link->map;
struct bpf_stab *stab = container_of(map, struct bpf_stab,
map);
if (psock->parser.enabled && stab->progs.skb_parser)
strp_stop = true;
list_del(&link->list);
sk_psock_free_link(link);
}
}
spin_unlock_bh(&psock->link_lock);
if (strp_stop) {
write_lock_bh(&sk->sk_callback_lock);
sk_psock_stop_strp(sk, psock);
write_unlock_bh(&sk->sk_callback_lock);
}
}
static void sock_map_unref(struct sock *sk, void *link_raw)
{
struct sk_psock *psock = sk_psock(sk);
if (likely(psock)) {
sock_map_del_link(sk, psock, link_raw);
sk_psock_put(sk, psock);
}
}
static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
struct sock *sk)
{
struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
bool skb_progs, sk_psock_is_new = false;
struct sk_psock *psock;
int ret;
skb_verdict = READ_ONCE(progs->skb_verdict);
skb_parser = READ_ONCE(progs->skb_parser);
skb_progs = skb_parser && skb_verdict;
if (skb_progs) {
skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
if (IS_ERR(skb_verdict))
return PTR_ERR(skb_verdict);
skb_parser = bpf_prog_inc_not_zero(skb_parser);
if (IS_ERR(skb_parser)) {
bpf_prog_put(skb_verdict);
return PTR_ERR(skb_parser);
}
}
msg_parser = READ_ONCE(progs->msg_parser);
if (msg_parser) {
msg_parser = bpf_prog_inc_not_zero(msg_parser);
if (IS_ERR(msg_parser)) {
ret = PTR_ERR(msg_parser);
goto out;
}
}
psock = sk_psock_get(sk);
if (psock) {
if (!sk_has_psock(sk)) {
ret = -EBUSY;
goto out_progs;
}
if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
(skb_progs && READ_ONCE(psock->progs.skb_parser))) {
sk_psock_put(sk, psock);
ret = -EBUSY;
goto out_progs;
}
} else {
psock = sk_psock_init(sk, map->numa_node);
if (!psock) {
ret = -ENOMEM;
goto out_progs;
}
sk_psock_is_new = true;
}
if (msg_parser)
psock_set_prog(&psock->progs.msg_parser, msg_parser);
if (sk_psock_is_new) {
ret = tcp_bpf_init(sk);
if (ret < 0)
goto out_drop;
} else {
tcp_bpf_reinit(sk);
}
write_lock_bh(&sk->sk_callback_lock);
if (skb_progs && !psock->parser.enabled) {
ret = sk_psock_init_strp(sk, psock);
if (ret) {
write_unlock_bh(&sk->sk_callback_lock);
goto out_drop;
}
psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
psock_set_prog(&psock->progs.skb_parser, skb_parser);
sk_psock_start_strp(sk, psock);
}
write_unlock_bh(&sk->sk_callback_lock);
return 0;
out_drop:
sk_psock_put(sk, psock);
out_progs:
if (msg_parser)
bpf_prog_put(msg_parser);
out:
if (skb_progs) {
bpf_prog_put(skb_verdict);
bpf_prog_put(skb_parser);
}
return ret;
}
static void sock_map_free(struct bpf_map *map)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
int i;
synchronize_rcu();
rcu_read_lock();
raw_spin_lock_bh(&stab->lock);
for (i = 0; i < stab->map.max_entries; i++) {
struct sock **psk = &stab->sks[i];
struct sock *sk;
sk = xchg(psk, NULL);
if (sk)
sock_map_unref(sk, psk);
}
raw_spin_unlock_bh(&stab->lock);
rcu_read_unlock();
bpf_map_area_free(stab->sks);
kfree(stab);
}
static void sock_map_release_progs(struct bpf_map *map)
{
psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
}
static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
WARN_ON_ONCE(!rcu_read_lock_held());
if (unlikely(key >= map->max_entries))
return NULL;
return READ_ONCE(stab->sks[key]);
}
static void *sock_map_lookup(struct bpf_map *map, void *key)
{
return ERR_PTR(-EOPNOTSUPP);
}
static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
struct sock **psk)
{
struct sock *sk;
raw_spin_lock_bh(&stab->lock);
sk = *psk;
if (!sk_test || sk_test == sk)
*psk = NULL;
raw_spin_unlock_bh(&stab->lock);
if (unlikely(!sk))
return -EINVAL;
sock_map_unref(sk, psk);
return 0;
}
static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
void *link_raw)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
__sock_map_delete(stab, sk, link_raw);
}
static int sock_map_delete_elem(struct bpf_map *map, void *key)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
u32 i = *(u32 *)key;
struct sock **psk;
if (unlikely(i >= map->max_entries))
return -EINVAL;
psk = &stab->sks[i];
return __sock_map_delete(stab, NULL, psk);
}
static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
u32 i = key ? *(u32 *)key : U32_MAX;
u32 *key_next = next;
if (i == stab->map.max_entries - 1)
return -ENOENT;
if (i >= stab->map.max_entries)
*key_next = 0;
else
*key_next = i + 1;
return 0;
}
static int sock_map_update_common(struct bpf_map *map, u32 idx,
struct sock *sk, u64 flags)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
struct sk_psock_link *link;
struct sk_psock *psock;
struct sock *osk;
int ret;
WARN_ON_ONCE(!rcu_read_lock_held());
if (unlikely(flags > BPF_EXIST))
return -EINVAL;
if (unlikely(idx >= map->max_entries))
return -E2BIG;
link = sk_psock_init_link();
if (!link)
return -ENOMEM;
ret = sock_map_link(map, &stab->progs, sk);
if (ret < 0)
goto out_free;
psock = sk_psock(sk);
WARN_ON_ONCE(!psock);
raw_spin_lock_bh(&stab->lock);
osk = stab->sks[idx];
if (osk && flags == BPF_NOEXIST) {
ret = -EEXIST;
goto out_unlock;
} else if (!osk && flags == BPF_EXIST) {
ret = -ENOENT;
goto out_unlock;
}
sock_map_add_link(psock, link, map, &stab->sks[idx]);
stab->sks[idx] = sk;
if (osk)
sock_map_unref(osk, &stab->sks[idx]);
raw_spin_unlock_bh(&stab->lock);
return 0;
out_unlock:
raw_spin_unlock_bh(&stab->lock);
if (psock)
sk_psock_put(sk, psock);
out_free:
sk_psock_free_link(link);
return ret;
}
static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
{
return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
}
static bool sock_map_sk_is_suitable(const struct sock *sk)
{
return sk->sk_type == SOCK_STREAM &&
sk->sk_protocol == IPPROTO_TCP;
}
static int sock_map_update_elem(struct bpf_map *map, void *key,
void *value, u64 flags)
{
u32 ufd = *(u32 *)value;
u32 idx = *(u32 *)key;
struct socket *sock;
struct sock *sk;
int ret;
sock = sockfd_lookup(ufd, &ret);
if (!sock)
return ret;
sk = sock->sk;
if (!sk) {
ret = -EINVAL;
goto out;
}
if (!sock_map_sk_is_suitable(sk) ||
sk->sk_state != TCP_ESTABLISHED) {
ret = -EOPNOTSUPP;
goto out;
}
sock_map_sk_acquire(sk);
ret = sock_map_update_common(map, idx, sk, flags);
sock_map_sk_release(sk);
out:
fput(sock->file);
return ret;
}
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
if (likely(sock_map_sk_is_suitable(sops->sk) &&
sock_map_op_okay(sops)))
return sock_map_update_common(map, *(u32 *)key, sops->sk,
flags);
return -EOPNOTSUPP;
}
const struct bpf_func_proto bpf_sock_map_update_proto = {
.func = bpf_sock_map_update,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
struct bpf_map *, map, u32, key, u64, flags)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
tcb->bpf.flags = flags;
tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key);
if (!tcb->bpf.sk_redir)
return SK_DROP;
return SK_PASS;
}
const struct bpf_func_proto bpf_sk_redirect_map_proto = {
.func = bpf_sk_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
struct bpf_map *, map, u32, key, u64, flags)
{
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
msg->flags = flags;
msg->sk_redir = __sock_map_lookup_elem(map, key);
if (!msg->sk_redir)
return SK_DROP;
return SK_PASS;
}
const struct bpf_func_proto bpf_msg_redirect_map_proto = {
.func = bpf_msg_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_ANYTHING,
};
const struct bpf_map_ops sock_map_ops = {
.map_alloc = sock_map_alloc,
.map_free = sock_map_free,
.map_get_next_key = sock_map_get_next_key,
.map_update_elem = sock_map_update_elem,
.map_delete_elem = sock_map_delete_elem,
.map_lookup_elem = sock_map_lookup,
.map_release_uref = sock_map_release_progs,
.map_check_btf = map_check_no_btf,
};
struct bpf_htab_elem {
struct rcu_head rcu;
u32 hash;
struct sock *sk;
struct hlist_node node;
u8 key[0];
};
struct bpf_htab_bucket {
struct hlist_head head;
raw_spinlock_t lock;
};
struct bpf_htab {
struct bpf_map map;
struct bpf_htab_bucket *buckets;
u32 buckets_num;
u32 elem_size;
struct sk_psock_progs progs;
atomic_t count;
};
static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
{
return jhash(key, len, 0);
}
static struct bpf_htab_bucket *sock_hash_select_bucket(struct bpf_htab *htab,
u32 hash)
{
return &htab->buckets[hash & (htab->buckets_num - 1)];
}
static struct bpf_htab_elem *
sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
u32 key_size)
{
struct bpf_htab_elem *elem;
hlist_for_each_entry_rcu(elem, head, node) {
if (elem->hash == hash &&
!memcmp(&elem->key, key, key_size))
return elem;
}
return NULL;
}
static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
u32 key_size = map->key_size, hash;
struct bpf_htab_bucket *bucket;
struct bpf_htab_elem *elem;
WARN_ON_ONCE(!rcu_read_lock_held());
hash = sock_hash_bucket_hash(key, key_size);
bucket = sock_hash_select_bucket(htab, hash);
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
return elem ? elem->sk : NULL;
}
static void sock_hash_free_elem(struct bpf_htab *htab,
struct bpf_htab_elem *elem)
{
atomic_dec(&htab->count);
kfree_rcu(elem, rcu);
}
static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
void *link_raw)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct bpf_htab_elem *elem_probe, *elem = link_raw;
struct bpf_htab_bucket *bucket;
WARN_ON_ONCE(!rcu_read_lock_held());
bucket = sock_hash_select_bucket(htab, elem->hash);
/* elem may be deleted in parallel from the map, but access here
* is okay since it's going away only after RCU grace period.
* However, we need to check whether it's still present.
*/
raw_spin_lock_bh(&bucket->lock);
elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
elem->key, map->key_size);
if (elem_probe && elem_probe == elem) {
hlist_del_rcu(&elem->node);
sock_map_unref(elem->sk, elem);
sock_hash_free_elem(htab, elem);
}
raw_spin_unlock_bh(&bucket->lock);
}
static int sock_hash_delete_elem(struct bpf_map *map, void *key)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
u32 hash, key_size = map->key_size;
struct bpf_htab_bucket *bucket;
struct bpf_htab_elem *elem;
int ret = -ENOENT;
hash = sock_hash_bucket_hash(key, key_size);
bucket = sock_hash_select_bucket(htab, hash);
raw_spin_lock_bh(&bucket->lock);
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
if (elem) {
hlist_del_rcu(&elem->node);
sock_map_unref(elem->sk, elem);
sock_hash_free_elem(htab, elem);
ret = 0;
}
raw_spin_unlock_bh(&bucket->lock);
return ret;
}
static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab,
void *key, u32 key_size,
u32 hash, struct sock *sk,
struct bpf_htab_elem *old)
{
struct bpf_htab_elem *new;
if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
if (!old) {
atomic_dec(&htab->count);
return ERR_PTR(-E2BIG);
}
}
new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
htab->map.numa_node);
if (!new) {
atomic_dec(&htab->count);
return ERR_PTR(-ENOMEM);
}
memcpy(new->key, key, key_size);
new->sk = sk;
new->hash = hash;
return new;
}
static int sock_hash_update_common(struct bpf_map *map, void *key,
struct sock *sk, u64 flags)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
u32 key_size = map->key_size, hash;
struct bpf_htab_elem *elem, *elem_new;
struct bpf_htab_bucket *bucket;
struct sk_psock_link *link;
struct sk_psock *psock;
int ret;
WARN_ON_ONCE(!rcu_read_lock_held());
if (unlikely(flags > BPF_EXIST))
return -EINVAL;
link = sk_psock_init_link();
if (!link)
return -ENOMEM;
ret = sock_map_link(map, &htab->progs, sk);
if (ret < 0)
goto out_free;
psock = sk_psock(sk);
WARN_ON_ONCE(!psock);
hash = sock_hash_bucket_hash(key, key_size);
bucket = sock_hash_select_bucket(htab, hash);
raw_spin_lock_bh(&bucket->lock);
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
if (elem && flags == BPF_NOEXIST) {
ret = -EEXIST;
goto out_unlock;
} else if (!elem && flags == BPF_EXIST) {
ret = -ENOENT;
goto out_unlock;
}
elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
if (IS_ERR(elem_new)) {
ret = PTR_ERR(elem_new);
goto out_unlock;
}
sock_map_add_link(psock, link, map, elem_new);
/* Add new element to the head of the list, so that
* concurrent search will find it before old elem.
*/
hlist_add_head_rcu(&elem_new->node, &bucket->head);
if (elem) {
hlist_del_rcu(&elem->node);
sock_map_unref(elem->sk, elem);
sock_hash_free_elem(htab, elem);
}
raw_spin_unlock_bh(&bucket->lock);
return 0;
out_unlock:
raw_spin_unlock_bh(&bucket->lock);
sk_psock_put(sk, psock);
out_free:
sk_psock_free_link(link);
return ret;
}
static int sock_hash_update_elem(struct bpf_map *map, void *key,
void *value, u64 flags)
{
u32 ufd = *(u32 *)value;
struct socket *sock;
struct sock *sk;
int ret;
sock = sockfd_lookup(ufd, &ret);
if (!sock)
return ret;
sk = sock->sk;
if (!sk) {
ret = -EINVAL;
goto out;
}
if (!sock_map_sk_is_suitable(sk) ||
sk->sk_state != TCP_ESTABLISHED) {
ret = -EOPNOTSUPP;
goto out;
}
sock_map_sk_acquire(sk);
ret = sock_hash_update_common(map, key, sk, flags);
sock_map_sk_release(sk);
out:
fput(sock->file);
return ret;
}
static int sock_hash_get_next_key(struct bpf_map *map, void *key,
void *key_next)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct bpf_htab_elem *elem, *elem_next;
u32 hash, key_size = map->key_size;
struct hlist_head *head;
int i = 0;
if (!key)
goto find_first_elem;
hash = sock_hash_bucket_hash(key, key_size);
head = &sock_hash_select_bucket(htab, hash)->head;
elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
if (!elem)
goto find_first_elem;
elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)),
struct bpf_htab_elem, node);
if (elem_next) {
memcpy(key_next, elem_next->key, key_size);
return 0;
}
i = hash & (htab->buckets_num - 1);
i++;
find_first_elem:
for (; i < htab->buckets_num; i++) {
head = &sock_hash_select_bucket(htab, i)->head;
elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
struct bpf_htab_elem, node);
if (elem_next) {
memcpy(key_next, elem_next->key, key_size);
return 0;
}
}
return -ENOENT;
}
static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
{
struct bpf_htab *htab;
int i, err;
u64 cost;
if (!capable(CAP_NET_ADMIN))
return ERR_PTR(-EPERM);
if (attr->max_entries == 0 ||
attr->key_size == 0 ||
attr->value_size != 4 ||
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
return ERR_PTR(-EINVAL);
if (attr->key_size > MAX_BPF_STACK)
return ERR_PTR(-E2BIG);
htab = kzalloc(sizeof(*htab), GFP_USER);
if (!htab)
return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&htab->map, attr);
htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
htab->elem_size = sizeof(struct bpf_htab_elem) +
round_up(htab->map.key_size, 8);
if (htab->buckets_num == 0 ||
htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) {
err = -EINVAL;
goto free_htab;
}
cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) +
(u64) htab->elem_size * htab->map.max_entries;
if (cost >= U32_MAX - PAGE_SIZE) {
err = -EINVAL;
goto free_htab;
}
htab->buckets = bpf_map_area_alloc(htab->buckets_num *
sizeof(struct bpf_htab_bucket),
htab->map.numa_node);
if (!htab->buckets) {
err = -ENOMEM;
goto free_htab;
}
for (i = 0; i < htab->buckets_num; i++) {
INIT_HLIST_HEAD(&htab->buckets[i].head);
raw_spin_lock_init(&htab->buckets[i].lock);
}
return &htab->map;
free_htab:
kfree(htab);
return ERR_PTR(err);
}
static void sock_hash_free(struct bpf_map *map)
{
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
struct bpf_htab_bucket *bucket;
struct bpf_htab_elem *elem;
struct hlist_node *node;
int i;
synchronize_rcu();
rcu_read_lock();
for (i = 0; i < htab->buckets_num; i++) {
bucket = sock_hash_select_bucket(htab, i);
raw_spin_lock_bh(&bucket->lock);
hlist_for_each_entry_safe(elem, node, &bucket->head, node) {
hlist_del_rcu(&elem->node);
sock_map_unref(elem->sk, elem);
}
raw_spin_unlock_bh(&bucket->lock);
}
rcu_read_unlock();
bpf_map_area_free(htab->buckets);
kfree(htab);
}
static void sock_hash_release_progs(struct bpf_map *map)
{
psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs);
}
BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
if (likely(sock_map_sk_is_suitable(sops->sk) &&
sock_map_op_okay(sops)))
return sock_hash_update_common(map, key, sops->sk, flags);
return -EOPNOTSUPP;
}
const struct bpf_func_proto bpf_sock_hash_update_proto = {
.func = bpf_sock_hash_update,
.gpl_only = false,
.pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
struct bpf_map *, map, void *, key, u64, flags)
{
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
tcb->bpf.flags = flags;
tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key);
if (!tcb->bpf.sk_redir)
return SK_DROP;
return SK_PASS;
}
const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
.func = bpf_sk_redirect_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
struct bpf_map *, map, void *, key, u64, flags)
{
if (unlikely(flags & ~(BPF_F_INGRESS)))
return SK_DROP;
msg->flags = flags;
msg->sk_redir = __sock_hash_lookup_elem(map, key);
if (!msg->sk_redir)
return SK_DROP;
return SK_PASS;
}
const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
.func = bpf_msg_redirect_hash,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
const struct bpf_map_ops sock_hash_ops = {
.map_alloc = sock_hash_alloc,
.map_free = sock_hash_free,
.map_get_next_key = sock_hash_get_next_key,
.map_update_elem = sock_hash_update_elem,
.map_delete_elem = sock_hash_delete_elem,
.map_lookup_elem = sock_map_lookup,
.map_release_uref = sock_hash_release_progs,
.map_check_btf = map_check_no_btf,
};
static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
{
switch (map->map_type) {
case BPF_MAP_TYPE_SOCKMAP:
return &container_of(map, struct bpf_stab, map)->progs;
case BPF_MAP_TYPE_SOCKHASH:
return &container_of(map, struct bpf_htab, map)->progs;
default:
break;
}
return NULL;
}
int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
u32 which)
{
struct sk_psock_progs *progs = sock_map_progs(map);
if (!progs)
return -EOPNOTSUPP;
switch (which) {
case BPF_SK_MSG_VERDICT:
psock_set_prog(&progs->msg_parser, prog);
break;
case BPF_SK_SKB_STREAM_PARSER:
psock_set_prog(&progs->skb_parser, prog);
break;
case BPF_SK_SKB_STREAM_VERDICT:
psock_set_prog(&progs->skb_verdict, prog);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link)
{
switch (link->map->map_type) {
case BPF_MAP_TYPE_SOCKMAP:
return sock_map_delete_from_link(link->map, sk,
link->link_raw);
case BPF_MAP_TYPE_SOCKHASH:
return sock_hash_delete_from_link(link->map, sk,
link->link_raw);
default:
break;
}
}
net/ipv4/Makefile
View file @ 604326b4
......@@ -63,6 +63,7 @@ obj-$(CONFIG_TCP_CONG_SCALABLE) += tcp_scalable.o
obj-$(CONFIG_TCP_CONG_LP) += tcp_lp.o
obj-$(CONFIG_TCP_CONG_YEAH) += tcp_yeah.o
obj-$(CONFIG_TCP_CONG_ILLINOIS) += tcp_illinois.o
obj-$(CONFIG_NET_SOCK_MSG) += tcp_bpf.o
obj-$(CONFIG_NETLABEL) += cipso_ipv4.o
obj-$(CONFIG_XFRM) += xfrm4_policy.o xfrm4_state.o xfrm4_input.o \
......
net/ipv4/tcp_bpf.c 0 → 100644
View file @ 604326b4
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
#include <linux/skmsg.h>
#include <linux/filter.h>
#include <linux/bpf.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <net/inet_common.h>
static bool tcp_bpf_stream_read(const struct sock *sk)
{
struct sk_psock *psock;
bool empty = true;
rcu_read_lock();
psock = sk_psock(sk);
if (likely(psock))
empty = list_empty(&psock->ingress_msg);
rcu_read_unlock();
return !empty;
}
static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock,
int flags, long timeo, int *err)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int ret;
add_wait_queue(sk_sleep(sk), &wait);
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
ret = sk_wait_event(sk, &timeo,
!list_empty(&psock->ingress_msg) ||
!skb_queue_empty(&sk->sk_receive_queue), &wait);
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
remove_wait_queue(sk_sleep(sk), &wait);
return ret;
}
int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
struct msghdr *msg, int len)
{
struct iov_iter *iter = &msg->msg_iter;
int i, ret, copied = 0;
while (copied != len) {
struct scatterlist *sge;
struct sk_msg *msg_rx;
msg_rx = list_first_entry_or_null(&psock->ingress_msg,
struct sk_msg, list);
if (unlikely(!msg_rx))
break;
i = msg_rx->sg.start;
do {
struct page *page;
int copy;
sge = sk_msg_elem(msg_rx, i);
copy = sge->length;
page = sg_page(sge);
if (copied + copy > len)
copy = len - copied;
ret = copy_page_to_iter(page, sge->offset, copy, iter);
if (ret != copy) {
msg_rx->sg.start = i;
return -EFAULT;
}
copied += copy;
sge->offset += copy;
sge->length -= copy;
sk_mem_uncharge(sk, copy);
if (!sge->length) {
i++;
if (i == MAX_SKB_FRAGS)
i = 0;
if (!msg_rx->skb)
put_page(page);
}
if (copied == len)
break;
} while (i != msg_rx->sg.end);
msg_rx->sg.start = i;
if (!sge->length && msg_rx->sg.start == msg_rx->sg.end) {
list_del(&msg_rx->list);
if (msg_rx->skb)
consume_skb(msg_rx->skb);
kfree(msg_rx);
}
}
return copied;
}
EXPORT_SYMBOL_GPL(__tcp_bpf_recvmsg);
int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len)
{
struct sk_psock *psock;
int copied, ret;
if (unlikely(flags & MSG_ERRQUEUE))
return inet_recv_error(sk, msg, len, addr_len);
if (!skb_queue_empty(&sk->sk_receive_queue))
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
psock = sk_psock_get(sk);
if (unlikely(!psock))
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
lock_sock(sk);
msg_bytes_ready:
copied = __tcp_bpf_recvmsg(sk, psock, msg, len);
if (!copied) {
int data, err = 0;
long timeo;
timeo = sock_rcvtimeo(sk, nonblock);
data = tcp_bpf_wait_data(sk, psock, flags, timeo, &err);
if (data) {
if (skb_queue_empty(&sk->sk_receive_queue))
goto msg_bytes_ready;
release_sock(sk);
sk_psock_put(sk, psock);
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
}
if (err) {
ret = err;
goto out;
}
}
ret = copied;
out:
release_sock(sk);
sk_psock_put(sk, psock);
return ret;
}
static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg, u32 apply_bytes, int flags)
{
bool apply = apply_bytes;
struct scatterlist *sge;
u32 size, copied = 0;
struct sk_msg *tmp;
int i, ret = 0;
tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL);
if (unlikely(!tmp))
return -ENOMEM;
lock_sock(sk);
tmp->sg.start = msg->sg.start;
i = msg->sg.start;
do {
sge = sk_msg_elem(msg, i);
size = (apply && apply_bytes < sge->length) ?
apply_bytes : sge->length;
if (!sk_wmem_schedule(sk, size)) {
if (!copied)
ret = -ENOMEM;
break;
}
sk_mem_charge(sk, size);
sk_msg_xfer(tmp, msg, i, size);
copied += size;
if (sge->length)
get_page(sk_msg_page(tmp, i));
sk_msg_iter_var_next(i);
tmp->sg.end = i;
if (apply) {
apply_bytes -= size;
if (!apply_bytes)
break;
}
} while (i != msg->sg.end);
if (!ret) {
msg->sg.start = i;
msg->sg.size -= apply_bytes;
sk_psock_queue_msg(psock, tmp);
sk->sk_data_ready(sk);
} else {
sk_msg_free(sk, tmp);
kfree(tmp);
}
release_sock(sk);
return ret;
}
static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
int flags, bool uncharge)
{
bool apply = apply_bytes;
struct scatterlist *sge;
struct page *page;
int size, ret = 0;
u32 off;
while (1) {
sge = sk_msg_elem(msg, msg->sg.start);
size = (apply && apply_bytes < sge->length) ?
apply_bytes : sge->length;
off = sge->offset;
page = sg_page(sge);
tcp_rate_check_app_limited(sk);
retry:
ret = do_tcp_sendpages(sk, page, off, size, flags);
if (ret <= 0)
return ret;
if (apply)
apply_bytes -= ret;
msg->sg.size -= ret;
sge->offset += ret;
sge->length -= ret;
if (uncharge)
sk_mem_uncharge(sk, ret);
if (ret != size) {
size -= ret;
off += ret;
goto retry;
}
if (!sge->length) {
put_page(page);
sk_msg_iter_next(msg, start);
sg_init_table(sge, 1);
if (msg->sg.start == msg->sg.end)
break;
}
if (apply && !apply_bytes)
break;
}
return 0;
}
static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
u32 apply_bytes, int flags, bool uncharge)
{
int ret;
lock_sock(sk);
ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge);
release_sock(sk);
return ret;
}
int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
u32 bytes, int flags)
{
bool ingress = sk_msg_to_ingress(msg);
struct sk_psock *psock = sk_psock_get(sk);
int ret;
if (unlikely(!psock)) {
sk_msg_free(sk, msg);
return 0;
}
ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
tcp_bpf_push_locked(sk, msg, bytes, flags, false);
sk_psock_put(sk, psock);
return ret;
}
EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);
static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
struct sk_msg *msg, int *copied, int flags)
{
bool cork = false, enospc = msg->sg.start == msg->sg.end;
struct sock *sk_redir;
u32 tosend;
int ret;
more_data:
if (psock->eval == __SK_NONE)
psock->eval = sk_psock_msg_verdict(sk, psock, msg);
if (msg->cork_bytes &&
msg->cork_bytes > msg->sg.size && !enospc) {
psock->cork_bytes = msg->cork_bytes - msg->sg.size;
if (!psock->cork) {
psock->cork = kzalloc(sizeof(*psock->cork),
GFP_ATOMIC | __GFP_NOWARN);
if (!psock->cork)
return -ENOMEM;
}
memcpy(psock->cork, msg, sizeof(*msg));
return 0;
}
tosend = msg->sg.size;
if (psock->apply_bytes && psock->apply_bytes < tosend)
tosend = psock->apply_bytes;
switch (psock->eval) {
case __SK_PASS:
ret = tcp_bpf_push(sk, msg, tosend, flags, true);
if (unlikely(ret)) {
*copied -= sk_msg_free(sk, msg);
break;
}
sk_msg_apply_bytes(psock, tosend);
break;
case __SK_REDIRECT:
sk_redir = psock->sk_redir;
sk_msg_apply_bytes(psock, tosend);
if (psock->cork) {
cork = true;
psock->cork = NULL;
}
sk_msg_return(sk, msg, tosend);
release_sock(sk);
ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
lock_sock(sk);
if (unlikely(ret < 0)) {
int free = sk_msg_free_nocharge(sk, msg);
if (!cork)
*copied -= free;
}
if (cork) {
sk_msg_free(sk, msg);
kfree(msg);
msg = NULL;
ret = 0;
}
break;
case __SK_DROP:
default:
sk_msg_free_partial(sk, msg, tosend);
sk_msg_apply_bytes(psock, tosend);
*copied -= tosend;
return -EACCES;
}
if (likely(!ret)) {
if (!psock->apply_bytes) {
psock->eval = __SK_NONE;
if (psock->sk_redir) {
sock_put(psock->sk_redir);
psock->sk_redir = NULL;
}
}
if (msg &&
msg->sg.data[msg->sg.start].page_link &&
msg->sg.data[msg->sg.start].length)
goto more_data;
}
return ret;
}
static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
struct sk_msg tmp, *msg_tx = NULL;
int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS;
int copied = 0, err = 0;
struct sk_psock *psock;
long timeo;
psock = sk_psock_get(sk);
if (unlikely(!psock))
return tcp_sendmsg(sk, msg, size);
lock_sock(sk);
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
while (msg_data_left(msg)) {
bool enospc = false;
u32 copy, osize;
if (sk->sk_err) {
err = -sk->sk_err;
goto out_err;
}
copy = msg_data_left(msg);
if (!sk_stream_memory_free(sk))
goto wait_for_sndbuf;
if (psock->cork) {
msg_tx = psock->cork;
} else {
msg_tx = &tmp;
sk_msg_init(msg_tx);
}
osize = msg_tx->sg.size;
err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1);
if (err) {
if (err != -ENOSPC)
goto wait_for_memory;
enospc = true;
copy = msg_tx->sg.size - osize;
}
err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
copy);
if (err < 0) {
sk_msg_trim(sk, msg_tx, osize);
goto out_err;
}
copied += copy;
if (psock->cork_bytes) {
if (size > psock->cork_bytes)
psock->cork_bytes = 0;
else
psock->cork_bytes -= size;
if (psock->cork_bytes && !enospc)
goto out_err;
/* All cork bytes are accounted, rerun the prog. */
psock->eval = __SK_NONE;
psock->cork_bytes = 0;
}
err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags);
if (unlikely(err < 0))
goto out_err;
continue;
wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
err = sk_stream_wait_memory(sk, &timeo);
if (err) {
if (msg_tx && msg_tx != psock->cork)
sk_msg_free(sk, msg_tx);
goto out_err;
}
}
out_err:
if (err < 0)
err = sk_stream_error(sk, msg->msg_flags, err);
release_sock(sk);
sk_psock_put(sk, psock);
return copied ? copied : err;
}
static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset,
size_t size, int flags)
{
struct sk_msg tmp, *msg = NULL;
int err = 0, copied = 0;
struct sk_psock *psock;
bool enospc = false;
psock = sk_psock_get(sk);
if (unlikely(!psock))
return tcp_sendpage(sk, page, offset, size, flags);
lock_sock(sk);
if (psock->cork) {
msg = psock->cork;
} else {
msg = &tmp;
sk_msg_init(msg);
}
/* Catch case where ring is full and sendpage is stalled. */
if (unlikely(sk_msg_full(msg)))
goto out_err;
sk_msg_page_add(msg, page, size, offset);
sk_mem_charge(sk, size);
copied = size;
if (sk_msg_full(msg))
enospc = true;
if (psock->cork_bytes) {
if (size > psock->cork_bytes)
psock->cork_bytes = 0;
else
psock->cork_bytes -= size;
if (psock->cork_bytes && !enospc)
goto out_err;
/* All cork bytes are accounted, rerun the prog. */
psock->eval = __SK_NONE;
psock->cork_bytes = 0;
}
err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags);
out_err:
release_sock(sk);
sk_psock_put(sk, psock);
return copied ? copied : err;
}
static void tcp_bpf_remove(struct sock *sk, struct sk_psock *psock)
{
struct sk_psock_link *link;
sk_psock_cork_free(psock);
__sk_psock_purge_ingress_msg(psock);
while ((link = sk_psock_link_pop(psock))) {
sk_psock_unlink(sk, link);
sk_psock_free_link(link);
}
}
static void tcp_bpf_unhash(struct sock *sk)
{
void (*saved_unhash)(struct sock *sk);
struct sk_psock *psock;
rcu_read_lock();
psock = sk_psock(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
if (sk->sk_prot->unhash)
sk->sk_prot->unhash(sk);
return;
}
saved_unhash = psock->saved_unhash;
tcp_bpf_remove(sk, psock);
rcu_read_unlock();
saved_unhash(sk);
}
static void tcp_bpf_close(struct sock *sk, long timeout)
{
void (*saved_close)(struct sock *sk, long timeout);
struct sk_psock *psock;
lock_sock(sk);
rcu_read_lock();
psock = sk_psock(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
release_sock(sk);
return sk->sk_prot->close(sk, timeout);
}
saved_close = psock->saved_close;
tcp_bpf_remove(sk, psock);
rcu_read_unlock();
release_sock(sk);
saved_close(sk, timeout);
}
enum {
TCP_BPF_IPV4,
TCP_BPF_IPV6,
TCP_BPF_NUM_PROTS,
};
enum {
TCP_BPF_BASE,
TCP_BPF_TX,
TCP_BPF_NUM_CFGS,
};
static struct proto *tcpv6_prot_saved __read_mostly;
static DEFINE_SPINLOCK(tcpv6_prot_lock);
static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS];
static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],
struct proto *base)
{
prot[TCP_BPF_BASE] = *base;
prot[TCP_BPF_BASE].unhash = tcp_bpf_unhash;
prot[TCP_BPF_BASE].close = tcp_bpf_close;
prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg;
prot[TCP_BPF_BASE].stream_memory_read = tcp_bpf_stream_read;
prot[TCP_BPF_TX] = prot[TCP_BPF_BASE];
prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg;
prot[TCP_BPF_TX].sendpage = tcp_bpf_sendpage;
}
static void tcp_bpf_check_v6_needs_rebuild(struct sock *sk, struct proto *ops)
{
if (sk->sk_family == AF_INET6 &&
unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) {
spin_lock_bh(&tcpv6_prot_lock);
if (likely(ops != tcpv6_prot_saved)) {
tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops);
smp_store_release(&tcpv6_prot_saved, ops);
}
spin_unlock_bh(&tcpv6_prot_lock);
}
}
static int __init tcp_bpf_v4_build_proto(void)
{
tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot);
return 0;
}
core_initcall(tcp_bpf_v4_build_proto);
static void tcp_bpf_update_sk_prot(struct sock *sk, struct sk_psock *psock)
{
int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
sk_psock_update_proto(sk, psock, &tcp_bpf_prots[family][config]);
}
static void tcp_bpf_reinit_sk_prot(struct sock *sk, struct sk_psock *psock)
{
int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
/* Reinit occurs when program types change e.g. TCP_BPF_TX is removed
* or added requiring sk_prot hook updates. We keep original saved
* hooks in this case.
*/
sk->sk_prot = &tcp_bpf_prots[family][config];
}
static int tcp_bpf_assert_proto_ops(struct proto *ops)
{
/* In order to avoid retpoline, we make assumptions when we call
* into ops if e.g. a psock is not present. Make sure they are
* indeed valid assumptions.
*/
return ops->recvmsg == tcp_recvmsg &&
ops->sendmsg == tcp_sendmsg &&
ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP;
}
void tcp_bpf_reinit(struct sock *sk)
{
struct sk_psock *psock;
sock_owned_by_me(sk);
rcu_read_lock();
psock = sk_psock(sk);
tcp_bpf_reinit_sk_prot(sk, psock);
rcu_read_unlock();
}
int tcp_bpf_init(struct sock *sk)
{
struct proto *ops = READ_ONCE(sk->sk_prot);
struct sk_psock *psock;
sock_owned_by_me(sk);
rcu_read_lock();
psock = sk_psock(sk);
if (unlikely(!psock || psock->sk_proto ||
tcp_bpf_assert_proto_ops(ops))) {
rcu_read_unlock();
return -EINVAL;
}
tcp_bpf_check_v6_needs_rebuild(sk, ops);
tcp_bpf_update_sk_prot(sk, psock);
rcu_read_unlock();
return 0;
}
net/strparser/Kconfig
View file @ 604326b4
config STREAM_PARSER
tristate
default n
def_bool n
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