Commit 965b57b4 authored by Cong Wang's avatar Cong Wang Committed by Daniel Borkmann

net: Introduce a new proto_ops ->read_skb()

Currently both splice() and sockmap use ->read_sock() to
read skb from receive queue, but for sockmap we only read
one entire skb at a time, so ->read_sock() is too conservative
to use. Introduce a new proto_ops ->read_skb() which supports
this sematic, with this we can finally pass the ownership of
skb to recv actors.

For non-TCP protocols, all ->read_sock() can be simply
converted to ->read_skb().
Signed-off-by: default avatarCong Wang <cong.wang@bytedance.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220615162014.89193-3-xiyou.wangcong@gmail.com
parent 04919bed
......@@ -152,6 +152,8 @@ struct module;
struct sk_buff;
typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
unsigned int, size_t);
typedef int (*skb_read_actor_t)(struct sock *, struct sk_buff *);
struct proto_ops {
int family;
......@@ -214,6 +216,8 @@ struct proto_ops {
*/
int (*read_sock)(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
/* This is different from read_sock(), it reads an entire skb at a time. */
int (*read_skb)(struct sock *sk, skb_read_actor_t recv_actor);
int (*sendpage_locked)(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
int (*sendmsg_locked)(struct sock *sk, struct msghdr *msg,
......
......@@ -672,8 +672,7 @@ void tcp_get_info(struct sock *, struct tcp_info *);
/* Read 'sendfile()'-style from a TCP socket */
int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
void tcp_initialize_rcv_mss(struct sock *sk);
......
......@@ -306,8 +306,7 @@ struct sock *__udp6_lib_lookup(struct net *net,
struct sk_buff *skb);
struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport);
int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
/* UDP uses skb->dev_scratch to cache as much information as possible and avoid
* possibly multiple cache miss on dequeue()
......
......@@ -1160,21 +1160,17 @@ static void sk_psock_done_strp(struct sk_psock *psock)
}
#endif /* CONFIG_BPF_STREAM_PARSER */
static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb,
unsigned int offset, size_t orig_len)
static int sk_psock_verdict_recv(struct sock *sk, struct sk_buff *skb)
{
struct sock *sk = (struct sock *)desc->arg.data;
struct sk_psock *psock;
struct bpf_prog *prog;
int ret = __SK_DROP;
int len = orig_len;
int len = skb->len;
/* clone here so sk_eat_skb() in tcp_read_sock does not drop our data */
skb = skb_clone(skb, GFP_ATOMIC);
if (!skb) {
desc->error = -ENOMEM;
if (!skb)
return 0;
}
rcu_read_lock();
psock = sk_psock(sk);
......@@ -1204,16 +1200,10 @@ static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb,
static void sk_psock_verdict_data_ready(struct sock *sk)
{
struct socket *sock = sk->sk_socket;
read_descriptor_t desc;
if (unlikely(!sock || !sock->ops || !sock->ops->read_sock))
if (unlikely(!sock || !sock->ops || !sock->ops->read_skb))
return;
desc.arg.data = sk;
desc.error = 0;
desc.count = 1;
sock->ops->read_sock(sk, &desc, sk_psock_verdict_recv);
sock->ops->read_skb(sk, sk_psock_verdict_recv);
}
void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock)
......
......@@ -1040,6 +1040,7 @@ const struct proto_ops inet_stream_ops = {
.sendpage = inet_sendpage,
.splice_read = tcp_splice_read,
.read_sock = tcp_read_sock,
.read_skb = tcp_read_skb,
.sendmsg_locked = tcp_sendmsg_locked,
.sendpage_locked = tcp_sendpage_locked,
.peek_len = tcp_peek_len,
......@@ -1067,7 +1068,7 @@ const struct proto_ops inet_dgram_ops = {
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
.sendmsg = inet_sendmsg,
.read_sock = udp_read_sock,
.read_skb = udp_read_skb,
.recvmsg = inet_recvmsg,
.mmap = sock_no_mmap,
.sendpage = inet_sendpage,
......
......@@ -1734,8 +1734,7 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
}
EXPORT_SYMBOL(tcp_read_sock);
int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor)
int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
{
struct tcp_sock *tp = tcp_sk(sk);
u32 seq = tp->copied_seq;
......@@ -1750,7 +1749,7 @@ int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
int used;
__skb_unlink(skb, &sk->sk_receive_queue);
used = recv_actor(desc, skb, 0, skb->len);
used = recv_actor(sk, skb);
if (used <= 0) {
if (!copied)
copied = used;
......@@ -1765,9 +1764,7 @@ int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
break;
}
consume_skb(skb);
if (!desc->count)
break;
WRITE_ONCE(tp->copied_seq, seq);
}
WRITE_ONCE(tp->copied_seq, seq);
......
......@@ -1797,8 +1797,7 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags,
}
EXPORT_SYMBOL(__skb_recv_udp);
int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor)
int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
{
int copied = 0;
......@@ -1820,7 +1819,7 @@ int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
continue;
}
used = recv_actor(desc, skb, 0, skb->len);
used = recv_actor(sk, skb);
if (used <= 0) {
if (!copied)
copied = used;
......@@ -1831,13 +1830,12 @@ int udp_read_sock(struct sock *sk, read_descriptor_t *desc,
}
kfree_skb(skb);
if (!desc->count)
break;
}
return copied;
}
EXPORT_SYMBOL(udp_read_sock);
EXPORT_SYMBOL(udp_read_skb);
/*
* This should be easy, if there is something there we
......
......@@ -702,6 +702,7 @@ const struct proto_ops inet6_stream_ops = {
.sendpage_locked = tcp_sendpage_locked,
.splice_read = tcp_splice_read,
.read_sock = tcp_read_sock,
.read_skb = tcp_read_skb,
.peek_len = tcp_peek_len,
#ifdef CONFIG_COMPAT
.compat_ioctl = inet6_compat_ioctl,
......@@ -727,7 +728,7 @@ const struct proto_ops inet6_dgram_ops = {
.getsockopt = sock_common_getsockopt, /* ok */
.sendmsg = inet6_sendmsg, /* retpoline's sake */
.recvmsg = inet6_recvmsg, /* retpoline's sake */
.read_sock = udp_read_sock,
.read_skb = udp_read_skb,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
.set_peek_off = sk_set_peek_off,
......
......@@ -741,10 +741,8 @@ static ssize_t unix_stream_splice_read(struct socket *, loff_t *ppos,
unsigned int flags);
static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
static int unix_stream_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor);
static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor);
static int unix_dgram_connect(struct socket *, struct sockaddr *,
int, int);
static int unix_seqpacket_sendmsg(struct socket *, struct msghdr *, size_t);
......@@ -798,7 +796,7 @@ static const struct proto_ops unix_stream_ops = {
.shutdown = unix_shutdown,
.sendmsg = unix_stream_sendmsg,
.recvmsg = unix_stream_recvmsg,
.read_sock = unix_stream_read_sock,
.read_skb = unix_stream_read_skb,
.mmap = sock_no_mmap,
.sendpage = unix_stream_sendpage,
.splice_read = unix_stream_splice_read,
......@@ -823,7 +821,7 @@ static const struct proto_ops unix_dgram_ops = {
.listen = sock_no_listen,
.shutdown = unix_shutdown,
.sendmsg = unix_dgram_sendmsg,
.read_sock = unix_read_sock,
.read_skb = unix_read_skb,
.recvmsg = unix_dgram_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
......@@ -2487,8 +2485,7 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t si
return __unix_dgram_recvmsg(sk, msg, size, flags);
}
static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor)
static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
{
int copied = 0;
......@@ -2503,7 +2500,7 @@ static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
if (!skb)
return err;
used = recv_actor(desc, skb, 0, skb->len);
used = recv_actor(sk, skb);
if (used <= 0) {
if (!copied)
copied = used;
......@@ -2514,7 +2511,6 @@ static int unix_read_sock(struct sock *sk, read_descriptor_t *desc,
}
kfree_skb(skb);
if (!desc->count)
break;
}
......@@ -2650,13 +2646,12 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk,
}
#endif
static int unix_stream_read_sock(struct sock *sk, read_descriptor_t *desc,
sk_read_actor_t recv_actor)
static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
{
if (unlikely(sk->sk_state != TCP_ESTABLISHED))
return -ENOTCONN;
return unix_read_sock(sk, desc, recv_actor);
return unix_read_skb(sk, recv_actor);
}
static int unix_stream_read_generic(struct unix_stream_read_state *state,
......
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