diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b9e44ad2b40d..05ec65698b95 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1800,6 +1800,39 @@ static int find_next_mappable_frag(const skb_frag_t *frag, return offset; } +static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len, + int nonblock, int flags, + struct scm_timestamping_internal *tss, + int *cmsg_flags); +static int receive_fallback_to_copy(struct sock *sk, + struct tcp_zerocopy_receive *zc, int inq) +{ + 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; + + zc->length = 0; + zc->recv_skip_hint = 0; + + if (copy_address != zc->copybuf_address) + return -EINVAL; + + err = import_single_range(READ, (void __user *)copy_address, + inq, &iov, &msg.msg_iter); + if (err) + return err; + + err = tcp_recvmsg_locked(sk, &msg, inq, /*nonblock=*/1, /*flags=*/0, + &tss_unused, &cmsg_flags_unused); + if (err < 0) + return err; + + zc->copybuf_len = err; + return 0; +} + static int tcp_copy_straggler_data(struct tcp_zerocopy_receive *zc, struct sk_buff *skb, u32 copylen, u32 *offset, u32 *seq) @@ -1904,6 +1937,9 @@ 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); + if (inq < PAGE_SIZE) { zc->length = 0; zc->recv_skip_hint = inq; |