diff options
author | David S. Miller <davem@davemloft.net> | 2011-09-22 03:23:13 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2011-09-22 03:23:13 -0400 |
commit | 8decf868790b48a727d7e7ca164f2bcd3c1389c0 (patch) | |
tree | b759a5f861f842af7ea76f9011b579d06e9d5508 /net/ipv4/tcp_ipv4.c | |
parent | 3fc72370186be2f9d4d6ef06d99e1caa5d92c564 (diff) | |
parent | d93dc5c4478c1fd5de85a3e8aece9aad7bbae044 (diff) | |
download | linux-3.10-8decf868790b48a727d7e7ca164f2bcd3c1389c0.tar.gz linux-3.10-8decf868790b48a727d7e7ca164f2bcd3c1389c0.tar.bz2 linux-3.10-8decf868790b48a727d7e7ca164f2bcd3c1389c0.zip |
Merge branch 'master' of github.com:davem330/net
Conflicts:
MAINTAINERS
drivers/net/Kconfig
drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c
drivers/net/ethernet/broadcom/tg3.c
drivers/net/wireless/iwlwifi/iwl-pci.c
drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c
drivers/net/wireless/rt2x00/rt2800usb.c
drivers/net/wireless/wl12xx/main.c
Diffstat (limited to 'net/ipv4/tcp_ipv4.c')
-rw-r--r-- | net/ipv4/tcp_ipv4.c | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index b3f26114b03..c29912cd83a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -808,20 +808,38 @@ static void tcp_v4_reqsk_destructor(struct request_sock *req) kfree(inet_rsk(req)->opt); } -static void syn_flood_warning(const struct sk_buff *skb) +/* + * Return 1 if a syncookie should be sent + */ +int tcp_syn_flood_action(struct sock *sk, + const struct sk_buff *skb, + const char *proto) { - const char *msg; + const char *msg = "Dropping request"; + int want_cookie = 0; + struct listen_sock *lopt; + + #ifdef CONFIG_SYN_COOKIES - if (sysctl_tcp_syncookies) + if (sysctl_tcp_syncookies) { msg = "Sending cookies"; - else + want_cookie = 1; + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES); + } else #endif - msg = "Dropping request"; + NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); - pr_info("TCP: Possible SYN flooding on port %d. %s.\n", - ntohs(tcp_hdr(skb)->dest), msg); + lopt = inet_csk(sk)->icsk_accept_queue.listen_opt; + if (!lopt->synflood_warned) { + lopt->synflood_warned = 1; + pr_info("%s: Possible SYN flooding on port %d. %s. " + " Check SNMP counters.\n", + proto, ntohs(tcp_hdr(skb)->dest), msg); + } + return want_cookie; } +EXPORT_SYMBOL(tcp_syn_flood_action); /* * Save and compile IPv4 options into the request_sock if needed. @@ -1235,11 +1253,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) __be32 saddr = ip_hdr(skb)->saddr; __be32 daddr = ip_hdr(skb)->daddr; __u32 isn = TCP_SKB_CB(skb)->when; -#ifdef CONFIG_SYN_COOKIES int want_cookie = 0; -#else -#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */ -#endif /* Never answer to SYNs send to broadcast or multicast */ if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) @@ -1250,14 +1264,9 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) * evidently real one. */ if (inet_csk_reqsk_queue_is_full(sk) && !isn) { - if (net_ratelimit()) - syn_flood_warning(skb); -#ifdef CONFIG_SYN_COOKIES - if (sysctl_tcp_syncookies) { - want_cookie = 1; - } else -#endif - goto drop; + want_cookie = tcp_syn_flood_action(sk, skb, "TCP"); + if (!want_cookie) + goto drop; } /* Accept backlog is full. If we have already queued enough @@ -1303,9 +1312,7 @@ int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) while (l-- > 0) *c++ ^= *hash_location++; -#ifdef CONFIG_SYN_COOKIES want_cookie = 0; /* not our kind of cookie */ -#endif tmp_ext.cookie_out_never = 0; /* false */ tmp_ext.cookie_plus = tmp_opt.cookie_plus; } else if (!tp->rx_opt.cookie_in_always) { |