From b103cf34382f26ff48a87931b83f13b177b47c1a Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Mon, 19 Oct 2009 10:10:40 +0000 Subject: tcp: fix TCP_DEFER_ACCEPT retrans calculation Fix TCP_DEFER_ACCEPT conversion between seconds and retransmission to match the TCP SYN-ACK retransmission periods because the time is converted to such retransmissions. The old algorithm selects one more retransmission in some cases. Allow up to 255 retransmissions. Signed-off-by: Julian Anastasov Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 55 +++++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 43 insertions(+), 12 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 64d0af67582..9b2756fbdf9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -326,6 +326,43 @@ void tcp_enter_memory_pressure(struct sock *sk) EXPORT_SYMBOL(tcp_enter_memory_pressure); +/* Convert seconds to retransmits based on initial and max timeout */ +static u8 secs_to_retrans(int seconds, int timeout, int rto_max) +{ + u8 res = 0; + + if (seconds > 0) { + int period = timeout; + + res = 1; + while (seconds > period && res < 255) { + res++; + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return res; +} + +/* Convert retransmits to seconds based on initial and max timeout */ +static int retrans_to_secs(u8 retrans, int timeout, int rto_max) +{ + int period = 0; + + if (retrans > 0) { + period = timeout; + while (--retrans) { + timeout <<= 1; + if (timeout > rto_max) + timeout = rto_max; + period += timeout; + } + } + return period; +} + /* * Wait for a TCP event. * @@ -2163,16 +2200,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level, break; case TCP_DEFER_ACCEPT: - icsk->icsk_accept_queue.rskq_defer_accept = 0; - if (val > 0) { - /* Translate value in seconds to number of - * retransmits */ - while (icsk->icsk_accept_queue.rskq_defer_accept < 32 && - val > ((TCP_TIMEOUT_INIT / HZ) << - icsk->icsk_accept_queue.rskq_defer_accept)) - icsk->icsk_accept_queue.rskq_defer_accept++; - icsk->icsk_accept_queue.rskq_defer_accept++; - } + /* Translate value in seconds to number of retransmits */ + icsk->icsk_accept_queue.rskq_defer_accept = + secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ); break; case TCP_WINDOW_CLAMP: @@ -2353,8 +2384,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = (val ? : sysctl_tcp_fin_timeout) / HZ; break; case TCP_DEFER_ACCEPT: - val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 : - ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1)); + val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, + TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); break; case TCP_WINDOW_CLAMP: val = tp->window_clamp; -- cgit v1.2.3 From b6b39e8f3fbbb31001b836afec87bcaf4811a7bf Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 19 Oct 2009 19:41:06 +0000 Subject: tcp: Try to catch MSG_PEEK bug This patch tries to print out more information when we hit the MSG_PEEK bug in tcp_recvmsg. It's been around since at least 2005 and it's about time that we finally fix it. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 9b2756fbdf9..90b2e0649bf 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1442,7 +1442,9 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, goto found_ok_skb; if (tcp_hdr(skb)->fin) goto found_fin_ok; - WARN_ON(!(flags & MSG_PEEK)); + if (WARN_ON(!(flags & MSG_PEEK))) + printk(KERN_INFO "recvmsg bug 2: copied %X " + "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); } /* Well, if we have backlog, try to process it now yet. */ -- cgit v1.2.3 From c62f4c453ab4b0240ab857bfd089da2c01ad91e7 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Thu, 22 Oct 2009 21:37:56 -0700 Subject: net: use WARN() for the WARN_ON in commit b6b39e8f3fbbb Commit b6b39e8f3fbbb (tcp: Try to catch MSG_PEEK bug) added a printk() to the WARN_ON() that's in tcp.c. This patch changes this combination to WARN(); the advantage of WARN() is that the printk message shows up inside the message, so that kerneloops.org will collect the message. In addition, this gets rid of an extra if() statement. Signed-off-by: Arjan van de Ven Signed-off-by: David S. Miller --- net/ipv4/tcp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/ipv4/tcp.c') diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 90b2e0649bf..98440ad8255 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1442,9 +1442,9 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, goto found_ok_skb; if (tcp_hdr(skb)->fin) goto found_fin_ok; - if (WARN_ON(!(flags & MSG_PEEK))) - printk(KERN_INFO "recvmsg bug 2: copied %X " - "seq %X\n", *seq, TCP_SKB_CB(skb)->seq); + WARN(!(flags & MSG_PEEK), KERN_INFO "recvmsg bug 2: " + "copied %X seq %X\n", *seq, + TCP_SKB_CB(skb)->seq); } /* Well, if we have backlog, try to process it now yet. */ -- cgit v1.2.3