diff options
| -rw-r--r-- | include/linux/tcp.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/tcp.h | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 43 |
3 files changed, 43 insertions, 5 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 20585d5c4e1c..807776928cb8 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -228,7 +228,7 @@ struct tcp_sock { unused:2; u8 nonagle : 4,/* Disable Nagle algorithm? */ thin_lto : 1,/* Use linear timeouts for thin streams */ - unused1 : 1, + recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */ repair : 1, frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */ u8 repair_queue; diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index e9e8373b34b9..29eb659aa77a 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -123,6 +123,9 @@ enum { #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ #define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ #define TCP_ZEROCOPY_RECEIVE 35 +#define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */ + +#define TCP_CM_INQ TCP_INQ struct tcp_repair_opt { __u32 opt_code; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4028ddd14dd5..868ed74a76a8 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1889,6 +1889,22 @@ static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, } } +static int tcp_inq_hint(struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + u32 copied_seq = READ_ONCE(tp->copied_seq); + u32 rcv_nxt = READ_ONCE(tp->rcv_nxt); + int inq; + + inq = rcv_nxt - copied_seq; + if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) { + lock_sock(sk); + inq = tp->rcv_nxt - tp->copied_seq; + release_sock(sk); + } + return inq; +} + /* * This routine copies from a sock struct into the user buffer. * @@ -1905,13 +1921,14 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, u32 peek_seq; u32 *seq; unsigned long used; - int err; + int err, inq; int target; /* Read at least this many bytes */ long timeo; struct sk_buff *skb, *last; u32 urg_hole = 0; struct scm_timestamping tss; bool has_tss = false; + bool has_cmsg; if (unlikely(flags & MSG_ERRQUEUE)) return inet_recv_error(sk, msg, len, addr_len); @@ -1926,6 +1943,7 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, if (sk->sk_state == TCP_LISTEN) goto out; + has_cmsg = tp->recvmsg_inq; timeo = sock_rcvtimeo(sk, nonblock); /* Urgent data needs to be handled specially. */ @@ -2112,6 +2130,7 @@ skip_copy: if (TCP_SKB_CB(skb)->has_rxtstamp) { tcp_update_recv_tstamps(skb, &tss); has_tss = true; + has_cmsg = true; } if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) goto found_fin_ok; @@ -2131,13 +2150,20 @@ skip_copy: * on connected socket. I was just happy when found this 8) --ANK */ - if (has_tss) - tcp_recv_timestamp(msg, sk, &tss); - /* Clean up data we have read: This will do ACK frames. */ tcp_cleanup_rbuf(sk, copied); release_sock(sk); + + if (has_cmsg) { + if (has_tss) + tcp_recv_timestamp(msg, sk, &tss); + if (tp->recvmsg_inq) { + inq = tcp_inq_hint(sk); + put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); + } + } + return copied; out: @@ -3006,6 +3032,12 @@ static int do_tcp_setsockopt(struct sock *sk, int level, tp->notsent_lowat = val; sk->sk_write_space(sk); break; + case TCP_INQ: + if (val > 1 || val < 0) + err = -EINVAL; + else + tp->recvmsg_inq = val; + break; default: err = -ENOPROTOOPT; break; @@ -3431,6 +3463,9 @@ static int do_tcp_getsockopt(struct sock *sk, int level, case TCP_NOTSENT_LOWAT: val = tp->notsent_lowat; break; + case TCP_INQ: + val = tp->recvmsg_inq; + break; case TCP_SAVE_SYN: val = tp->save_syn; break; |