From 12ed8244ed8b31b023ea6d2851fd8b15f2999e9b Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 3 Feb 2016 09:46:51 +0200 Subject: [PATCH] ipv4: Namespaceify tcp syncookies sysctl knob Signed-off-by: Nikolay Borisov Signed-off-by: David S. Miller --- include/net/netns/ipv4.h | 2 ++ include/net/tcp.h | 1 - net/ipv4/syncookies.c | 4 +--- net/ipv4/sysctl_net_ipv4.c | 18 +++++++++--------- net/ipv4/tcp_input.c | 10 ++++++---- net/ipv4/tcp_ipv4.c | 3 ++- net/ipv4/tcp_minisocks.c | 3 --- net/ipv6/syncookies.c | 2 +- 8 files changed, 21 insertions(+), 22 deletions(-) diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 9e83084ab8c1..ac000fccdf0f 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -101,6 +101,8 @@ struct netns_ipv4 { int sysctl_tcp_syn_retries; int sysctl_tcp_synack_retries; + int sysctl_tcp_syncookies; + struct ping_group_range ping_group_range; atomic_t dev_addr_genid; diff --git a/include/net/tcp.h b/include/net/tcp.h index 05659e860039..1fb23b70d237 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -243,7 +243,6 @@ extern int sysctl_tcp_fin_timeout; extern int sysctl_tcp_retries1; extern int sysctl_tcp_retries2; extern int sysctl_tcp_orphan_retries; -extern int sysctl_tcp_syncookies; extern int sysctl_tcp_fastopen; extern int sysctl_tcp_retrans_collapse; extern int sysctl_tcp_stdurg; diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 643a86c49020..ba0dcffada3b 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -19,8 +19,6 @@ #include #include -extern int sysctl_tcp_syncookies; - static u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS] __read_mostly; #define COOKIEBITS 24 /* Upper bits store count */ @@ -307,7 +305,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) __u8 rcv_wscale; struct flowi4 fl4; - if (!sysctl_tcp_syncookies || !th->ack || th->rst) + if (!sock_net(sk)->ipv4.sysctl_tcp_syncookies || !th->ack || th->rst) goto out; if (tcp_synq_no_recent_overflow(sk)) diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index bb682e36d8b7..d80142570a8d 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -341,15 +341,6 @@ static struct ctl_table ipv4_table[] = { .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, -#ifdef CONFIG_SYN_COOKIES - { - .procname = "tcp_syncookies", - .data = &sysctl_tcp_syncookies, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = proc_dointvec - }, -#endif { .procname = "tcp_fastopen", .data = &sysctl_tcp_fastopen, @@ -960,6 +951,15 @@ static struct ctl_table ipv4_net_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, +#ifdef CONFIG_SYN_COOKIES + { + .procname = "tcp_syncookies", + .data = &init_net.ipv4.sysctl_tcp_syncookies, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, +#endif { } }; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 596c1cb6759a..b17aba42a368 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6163,9 +6163,10 @@ static bool tcp_syn_flood_action(const struct sock *sk, struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; const char *msg = "Dropping request"; bool want_cookie = false; + struct net *net = sock_net(sk); #ifdef CONFIG_SYN_COOKIES - if (sysctl_tcp_syncookies) { + if (net->ipv4.sysctl_tcp_syncookies) { msg = "Sending cookies"; want_cookie = true; NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDOCOOKIES); @@ -6174,7 +6175,7 @@ static bool tcp_syn_flood_action(const struct sock *sk, NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPREQQFULLDROP); if (!queue->synflood_warned && - sysctl_tcp_syncookies != 2 && + net->ipv4.sysctl_tcp_syncookies != 2 && xchg(&queue->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); @@ -6207,6 +6208,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, __u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn; struct tcp_options_received tmp_opt; struct tcp_sock *tp = tcp_sk(sk); + struct net *net = sock_net(sk); struct sock *fastopen_sk = NULL; struct dst_entry *dst = NULL; struct request_sock *req; @@ -6217,7 +6219,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, * limitations, they conserve resources and peer is * evidently real one. */ - if ((sysctl_tcp_syncookies == 2 || + if ((net->ipv4.sysctl_tcp_syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) { want_cookie = tcp_syn_flood_action(sk, skb, rsk_ops->slab_name); if (!want_cookie) @@ -6283,7 +6285,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, } } /* Kill the following clause, if you dislike this way. */ - else if (!sysctl_tcp_syncookies && + else if (!net->ipv4.sysctl_tcp_syncookies && (sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) < (sysctl_max_syn_backlog >> 2)) && !tcp_peer_is_proven(req, dst, false, diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 3146279695b9..98313d10a2e0 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -860,7 +860,6 @@ static void tcp_v4_reqsk_destructor(struct request_sock *req) kfree(inet_rsk(req)->opt); } - #ifdef CONFIG_TCP_MD5SIG /* * RFC2385 MD5 checksumming requires a mapping of @@ -2391,6 +2390,8 @@ static int __net_init tcp_sk_init(struct net *net) net->ipv4.sysctl_tcp_syn_retries = TCP_SYN_RETRIES; net->ipv4.sysctl_tcp_synack_retries = TCP_SYNACK_RETRIES; + net->ipv4.sysctl_tcp_syncookies = 0; + return 0; fail: tcp_sk_exit(net); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 75632a925824..fadd8b978951 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -27,9 +27,6 @@ #include #include -int sysctl_tcp_syncookies __read_mostly = 1; -EXPORT_SYMBOL(sysctl_tcp_syncookies); - int sysctl_tcp_abort_on_overflow __read_mostly; struct inet_timewait_death_row tcp_death_row = { diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 2906ef20795e..0e393ff7f5d0 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -148,7 +148,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) struct dst_entry *dst; __u8 rcv_wscale; - if (!sysctl_tcp_syncookies || !th->ack || th->rst) + if (!sock_net(sk)->ipv4.sysctl_tcp_syncookies || !th->ack || th->rst) goto out; if (tcp_synq_no_recent_overflow(sk)) -- 2.20.1