diff options
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 7 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 14 |
3 files changed, 19 insertions, 3 deletions
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index d151539da8e6..d3c09c12ee81 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -883,6 +883,13 @@ static struct ctl_table ipv4_net_table[] = { .mode = 0644, .proc_handler = proc_dointvec, }, + { + .procname = "tcp_probe_threshold", + .data = &init_net.ipv4.sysctl_tcp_probe_threshold, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, { } }; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 5a2dfed4783b..35790d977a2b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2460,6 +2460,7 @@ static int __net_init tcp_sk_init(struct net *net) } net->ipv4.sysctl_tcp_ecn = 2; net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; + net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; return 0; fail: diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 8bbd86cd81c8..ed024cbb097f 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1842,11 +1842,13 @@ static int tcp_mtu_probe(struct sock *sk) struct tcp_sock *tp = tcp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); struct sk_buff *skb, *nskb, *next; + struct net *net = sock_net(sk); int len; int probe_size; int size_needed; int copy; int mss_now; + int interval; /* Not currently probing/verifying, * not in recovery, @@ -1859,11 +1861,17 @@ static int tcp_mtu_probe(struct sock *sk) tp->rx_opt.num_sacks || tp->rx_opt.dsack) return -1; - /* Very simple search strategy: just double the MSS. */ + /* Use binary search for probe_size between tcp_mss_base, + * and current mss_clamp. if (search_high - search_low) + * smaller than a threshold, backoff from probing. + */ mss_now = tcp_current_mss(sk); - probe_size = 2 * tp->mss_cache; + probe_size = tcp_mtu_to_mss(sk, (icsk->icsk_mtup.search_high + + icsk->icsk_mtup.search_low) >> 1); size_needed = probe_size + (tp->reordering + 1) * tp->mss_cache; - if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high)) { + interval = icsk->icsk_mtup.search_high - icsk->icsk_mtup.search_low; + if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high) || + interval < max(1, net->ipv4.sysctl_tcp_probe_threshold)) { /* TODO: set timer for probe_converge_event */ return -1; } |