Commit 04a88637 authored by Jakub Kicinski's avatar Jakub Kicinski

Merge branch 'tcp-add-cmsg-rx-timestamps-to-rx-zerocopy'

Arjun Roy says:

====================
tcp: add CMSG+rx timestamps to rx. zerocopy

Provide CMSG and receive timestamp support to TCP
receive zerocopy. Patch 1 refactors CMSG pending state for
tcp_recvmsg() to avoid the use of magic numbers; patch 2 implements
receive timestamp via CMSG support for receive zerocopy, and uses the
constants added in patch 1.
====================

Link: https://lore.kernel.org/r/20210121004148.2340206-1-arjunroy.kdev@gmail.comSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 5225d5f5 7eeba170
......@@ -354,5 +354,9 @@ struct tcp_zerocopy_receive {
__u64 copybuf_address; /* in: copybuf address (small reads) */
__s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */
__u32 flags; /* in: flags */
__u64 msg_control; /* ancillary data */
__u64 msg_controllen;
__u32 msg_flags;
/* __u32 hole; Next we must add >1 u32 otherwise length checks fail. */
};
#endif /* _UAPI_LINUX_TCP_H */
......@@ -280,6 +280,12 @@
#include <asm/ioctls.h>
#include <net/busy_poll.h>
/* Track pending CMSGs. */
enum {
TCP_CMSG_INQ = 1,
TCP_CMSG_TS = 2
};
struct percpu_counter tcp_orphan_count;
EXPORT_SYMBOL_GPL(tcp_orphan_count);
......@@ -1739,6 +1745,20 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
}
EXPORT_SYMBOL(tcp_set_rcvlowat);
static void tcp_update_recv_tstamps(struct sk_buff *skb,
struct scm_timestamping_internal *tss)
{
if (skb->tstamp)
tss->ts[0] = ktime_to_timespec64(skb->tstamp);
else
tss->ts[0] = (struct timespec64) {0};
if (skb_hwtstamps(skb)->hwtstamp)
tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
else
tss->ts[2] = (struct timespec64) {0};
}
#ifdef CONFIG_MMU
static const struct vm_operations_struct tcp_vm_ops = {
};
......@@ -1842,13 +1862,13 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
struct scm_timestamping_internal *tss,
int *cmsg_flags);
static int receive_fallback_to_copy(struct sock *sk,
struct tcp_zerocopy_receive *zc, int inq)
struct tcp_zerocopy_receive *zc, int inq,
struct scm_timestamping_internal *tss)
{
unsigned long copy_address = (unsigned long)zc->copybuf_address;
struct scm_timestamping_internal tss_unused;
int err, cmsg_flags_unused;
struct msghdr msg = {};
struct iovec iov;
int err;
zc->length = 0;
zc->recv_skip_hint = 0;
......@@ -1862,7 +1882,7 @@ static int receive_fallback_to_copy(struct sock *sk,
return err;
err = tcp_recvmsg_locked(sk, &msg, inq, /*nonblock=*/1, /*flags=*/0,
&tss_unused, &cmsg_flags_unused);
tss, &zc->msg_flags);
if (err < 0)
return err;
......@@ -1903,21 +1923,27 @@ static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc,
return (__s32)copylen;
}
static int tcp_zerocopy_handle_leftover_data(struct tcp_zerocopy_receive *zc,
struct sock *sk,
struct sk_buff *skb,
u32 *seq,
s32 copybuf_len)
static int tcp_zc_handle_leftover(struct tcp_zerocopy_receive *zc,
struct sock *sk,
struct sk_buff *skb,
u32 *seq,
s32 copybuf_len,
struct scm_timestamping_internal *tss)
{
u32 offset, copylen = min_t(u32, copybuf_len, zc->recv_skip_hint);
if (!copylen)
return 0;
/* skb is null if inq < PAGE_SIZE. */
if (skb)
if (skb) {
offset = *seq - TCP_SKB_CB(skb)->seq;
else
} else {
skb = tcp_recv_skb(sk, *seq, &offset);
if (TCP_SKB_CB(skb)->has_rxtstamp) {
tcp_update_recv_tstamps(skb, tss);
zc->msg_flags |= TCP_CMSG_TS;
}
}
zc->copybuf_len = tcp_copy_straggler_data(zc, skb, copylen, &offset,
seq);
......@@ -2004,9 +2030,37 @@ static int tcp_zerocopy_vm_insert_batch(struct vm_area_struct *vma,
err);
}
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
struct scm_timestamping_internal *tss);
static void tcp_zc_finalize_rx_tstamp(struct sock *sk,
struct tcp_zerocopy_receive *zc,
struct scm_timestamping_internal *tss)
{
unsigned long msg_control_addr;
struct msghdr cmsg_dummy;
msg_control_addr = (unsigned long)zc->msg_control;
cmsg_dummy.msg_control = (void *)msg_control_addr;
cmsg_dummy.msg_controllen =
(__kernel_size_t)zc->msg_controllen;
cmsg_dummy.msg_flags = in_compat_syscall()
? MSG_CMSG_COMPAT : 0;
zc->msg_flags = 0;
if (zc->msg_control == msg_control_addr &&
zc->msg_controllen == cmsg_dummy.msg_controllen) {
tcp_recv_timestamp(&cmsg_dummy, sk, tss);
zc->msg_control = (__u64)
((uintptr_t)cmsg_dummy.msg_control);
zc->msg_controllen =
(__u64)cmsg_dummy.msg_controllen;
zc->msg_flags = (__u32)cmsg_dummy.msg_flags;
}
}
#define TCP_ZEROCOPY_PAGE_BATCH_SIZE 32
static int tcp_zerocopy_receive(struct sock *sk,
struct tcp_zerocopy_receive *zc)
struct tcp_zerocopy_receive *zc,
struct scm_timestamping_internal *tss)
{
u32 length = 0, offset, vma_len, avail_len, copylen = 0;
unsigned long address = (unsigned long)zc->address;
......@@ -2023,6 +2077,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
int ret;
zc->copybuf_len = 0;
zc->msg_flags = 0;
if (address & (PAGE_SIZE - 1) || address != zc->address)
return -EINVAL;
......@@ -2033,7 +2088,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
sock_rps_record_flow(sk);
if (inq && inq <= copybuf_len)
return receive_fallback_to_copy(sk, zc, inq);
return receive_fallback_to_copy(sk, zc, inq, tss);
if (inq < PAGE_SIZE) {
zc->length = 0;
......@@ -2078,6 +2133,11 @@ static int tcp_zerocopy_receive(struct sock *sk,
} else {
skb = tcp_recv_skb(sk, seq, &offset);
}
if (TCP_SKB_CB(skb)->has_rxtstamp) {
tcp_update_recv_tstamps(skb, tss);
zc->msg_flags |= TCP_CMSG_TS;
}
zc->recv_skip_hint = skb->len - offset;
frags = skb_advance_to_frag(skb, offset, &offset_frag);
if (!frags || offset_frag)
......@@ -2120,8 +2180,7 @@ static int tcp_zerocopy_receive(struct sock *sk,
mmap_read_unlock(current->mm);
/* Try to copy straggler data. */
if (!ret)
copylen = tcp_zerocopy_handle_leftover_data(zc, sk, skb, &seq,
copybuf_len);
copylen = tcp_zc_handle_leftover(zc, sk, skb, &seq, copybuf_len, tss);
if (length + copylen) {
WRITE_ONCE(tp->copied_seq, seq);
......@@ -2142,20 +2201,6 @@ static int tcp_zerocopy_receive(struct sock *sk,
}
#endif
static void tcp_update_recv_tstamps(struct sk_buff *skb,
struct scm_timestamping_internal *tss)
{
if (skb->tstamp)
tss->ts[0] = ktime_to_timespec64(skb->tstamp);
else
tss->ts[0] = (struct timespec64) {0};
if (skb_hwtstamps(skb)->hwtstamp)
tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
else
tss->ts[2] = (struct timespec64) {0};
}
/* Similar to __sock_recv_timestamp, but does not require an skb */
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
struct scm_timestamping_internal *tss)
......@@ -2272,7 +2317,7 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
goto out;
if (tp->recvmsg_inq)
*cmsg_flags = 1;
*cmsg_flags = TCP_CMSG_INQ;
timeo = sock_rcvtimeo(sk, nonblock);
/* Urgent data needs to be handled specially. */
......@@ -2453,7 +2498,7 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
if (TCP_SKB_CB(skb)->has_rxtstamp) {
tcp_update_recv_tstamps(skb, tss);
*cmsg_flags |= 2;
*cmsg_flags |= TCP_CMSG_TS;
}
if (used + offset < skb->len)
......@@ -2513,9 +2558,9 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
release_sock(sk);
if (cmsg_flags && ret >= 0) {
if (cmsg_flags & 2)
if (cmsg_flags & TCP_CMSG_TS)
tcp_recv_timestamp(msg, sk, &tss);
if (cmsg_flags & 1) {
if (cmsg_flags & TCP_CMSG_INQ) {
inq = tcp_inq_hint(sk);
put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
}
......@@ -4099,6 +4144,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
}
#ifdef CONFIG_MMU
case TCP_ZEROCOPY_RECEIVE: {
struct scm_timestamping_internal tss;
struct tcp_zerocopy_receive zc = {};
int err;
......@@ -4114,11 +4160,18 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
if (copy_from_user(&zc, optval, len))
return -EFAULT;
lock_sock(sk);
err = tcp_zerocopy_receive(sk, &zc);
err = tcp_zerocopy_receive(sk, &zc, &tss);
release_sock(sk);
if (len >= offsetofend(struct tcp_zerocopy_receive, err))
goto zerocopy_rcv_sk_err;
if (len >= offsetofend(struct tcp_zerocopy_receive, msg_flags))
goto zerocopy_rcv_cmsg;
switch (len) {
case offsetofend(struct tcp_zerocopy_receive, msg_flags):
goto zerocopy_rcv_cmsg;
case offsetofend(struct tcp_zerocopy_receive, msg_controllen):
case offsetofend(struct tcp_zerocopy_receive, msg_control):
case offsetofend(struct tcp_zerocopy_receive, flags):
case offsetofend(struct tcp_zerocopy_receive, copybuf_len):
case offsetofend(struct tcp_zerocopy_receive, copybuf_address):
case offsetofend(struct tcp_zerocopy_receive, err):
goto zerocopy_rcv_sk_err;
case offsetofend(struct tcp_zerocopy_receive, inq):
......@@ -4127,6 +4180,11 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
default:
goto zerocopy_rcv_out;
}
zerocopy_rcv_cmsg:
if (zc.msg_flags & TCP_CMSG_TS)
tcp_zc_finalize_rx_tstamp(sk, &zc, &tss);
else
zc.msg_flags = 0;
zerocopy_rcv_sk_err:
if (!err)
zc.err = sock_error(sk);
......
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