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| author | Eric Dumazet <edumazet@google.com> | 2015-09-29 17:42:51 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-09-30 02:53:10 +0300 |
| commit | 2985aaac010ebd5e562ce1a22cc61acbb0e40cf2 (patch) | |
| tree | 43f34a8d12365c7ee0e5101bb30332e8fbcc0827 | |
| parent | f964629e3338d9e5a78c9b354380d5a1e2fa4617 (diff) | |
| download | linux-2985aaac010ebd5e562ce1a22cc61acbb0e40cf2.tar.xz | |
tcp: constify tcp_syn_flood_action() socket argument
tcp_syn_flood_action() will soon be called with unlocked socket.
In order to avoid SYN flood warning being emitted multiple times,
use xchg().
Extend max_qlen_log and synflood_warned fields in struct listen_sock
to u32
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/request_sock.h | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 9 |
2 files changed, 7 insertions, 7 deletions
diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 90247ec7955b..c146b5284786 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -129,9 +129,8 @@ struct listen_sock { atomic_t qlen_dec; /* qlen = qlen_inc - qlen_dec */ atomic_t young_dec; - u8 max_qlen_log ____cacheline_aligned_in_smp; - u8 synflood_warned; - /* 2 bytes hole, try to use */ + u32 max_qlen_log ____cacheline_aligned_in_smp; + u32 synflood_warned; u32 hash_rnd; u32 nr_table_entries; struct request_sock *syn_table[0]; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 67b27aee8d28..e58cbcd2f07e 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6064,7 +6064,7 @@ EXPORT_SYMBOL(inet_reqsk_alloc); /* * Return true if a syncookie should be sent */ -static bool tcp_syn_flood_action(struct sock *sk, +static bool tcp_syn_flood_action(const struct sock *sk, const struct sk_buff *skb, const char *proto) { @@ -6082,11 +6082,12 @@ static bool tcp_syn_flood_action(struct sock *sk, NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); lopt = inet_csk(sk)->icsk_accept_queue.listen_opt; - if (!lopt->synflood_warned && sysctl_tcp_syncookies != 2) { - lopt->synflood_warned = 1; + if (!lopt->synflood_warned && + sysctl_tcp_syncookies != 2 && + xchg(&lopt->synflood_warned, 1) == 0) pr_info("%s: Possible SYN flooding on port %d. %s. Check SNMP counters.\n", proto, ntohs(tcp_hdr(skb)->dest), msg); - } + return want_cookie; } |