tcp: Namespace-ify sysctl_tcp_challenge_ack_limit

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index e98f473..e9895d4 100644 (file)
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -147,6 +147,7 @@ struct netns_ipv4 {
        int sysctl_tcp_tso_win_divisor;
        int sysctl_tcp_workaround_signed_windows;
        int sysctl_tcp_limit_output_bytes;
+       int sysctl_tcp_challenge_ack_limit;
        struct inet_timewait_death_row tcp_death_row;
        int sysctl_max_syn_backlog;
        int sysctl_tcp_fastopen;

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 33f9d30..afc2359 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -250,7 +250,6 @@ extern int sysctl_tcp_rmem[3];
 
 #define TCP_RACK_LOSS_DETECTION  0x1 /* Use RACK to detect losses */
 
-extern int sysctl_tcp_challenge_ack_limit;
 extern int sysctl_tcp_min_tso_segs;
 extern int sysctl_tcp_min_rtt_wlen;
 extern int sysctl_tcp_autocorking;

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 6caf5c4..e28b3b7 100644 (file)
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -457,13 +457,6 @@ static struct ctl_table ipv4_table[] = {
                .maxlen         = TCP_CA_NAME_MAX,
                .proc_handler   = proc_tcp_congestion_control,
        },
-       {
-               .procname       = "tcp_challenge_ack_limit",
-               .data           = &sysctl_tcp_challenge_ack_limit,
-               .maxlen         = sizeof(int),
-               .mode           = 0644,
-               .proc_handler   = proc_dointvec
-       },
 #ifdef CONFIG_NETLABEL
        {
                .procname       = "cipso_cache_enable",
@@ -1145,6 +1138,13 @@ static struct ctl_table ipv4_net_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
+       {
+               .procname       = "tcp_challenge_ack_limit",
+               .data           = &init_net.ipv4.sysctl_tcp_challenge_ack_limit,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec
+       },
        { }
 };
 

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ce48132..928048a 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -79,9 +79,6 @@
 #include <linux/unaligned/access_ok.h>
 #include <linux/static_key.h>
 
-/* rfc5961 challenge ack rate limiting */
-int sysctl_tcp_challenge_ack_limit = 1000;
-
 int sysctl_tcp_max_orphans __read_mostly = NR_FILE;
 int sysctl_tcp_min_rtt_wlen __read_mostly = 300;
 int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2;
@@ -3443,10 +3440,11 @@ static void tcp_send_challenge_ack(struct sock *sk, const struct sk_buff *skb)
        static u32 challenge_timestamp;
        static unsigned int challenge_count;
        struct tcp_sock *tp = tcp_sk(sk);
+       struct net *net = sock_net(sk);
        u32 count, now;
 
        /* First check our per-socket dupack rate limit. */
-       if (__tcp_oow_rate_limited(sock_net(sk),
+       if (__tcp_oow_rate_limited(net,
                                   LINUX_MIB_TCPACKSKIPPEDCHALLENGE,
                                   &tp->last_oow_ack_time))
                return;
@@ -3454,16 +3452,16 @@ static void tcp_send_challenge_ack(struct sock *sk, const struct sk_buff *skb)
        /* Then check host-wide RFC 5961 rate limit. */
        now = jiffies / HZ;
        if (now != challenge_timestamp) {
-               u32 half = (sysctl_tcp_challenge_ack_limit + 1) >> 1;
+               u32 ack_limit = net->ipv4.sysctl_tcp_challenge_ack_limit;
+               u32 half = (ack_limit + 1) >> 1;
 
                challenge_timestamp = now;
-               WRITE_ONCE(challenge_count, half +
-                          prandom_u32_max(sysctl_tcp_challenge_ack_limit));
+               WRITE_ONCE(challenge_count, half + prandom_u32_max(ack_limit));
        }
        count = READ_ONCE(challenge_count);
        if (count > 0) {
                WRITE_ONCE(challenge_count, count - 1);
-               NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPCHALLENGEACK);
+               NET_INC_STATS(net, LINUX_MIB_TCPCHALLENGEACK);
                tcp_send_ack(sk);
        }
 }

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 713b802..50ab3a3 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2501,6 +2501,8 @@ static int __net_init tcp_sk_init(struct net *net)
        net->ipv4.sysctl_tcp_tso_win_divisor = 3;
        /* Default TSQ limit of four TSO segments */
        net->ipv4.sysctl_tcp_limit_output_bytes = 262144;
+       /* rfc5961 challenge ack rate limiting */
+       net->ipv4.sysctl_tcp_challenge_ack_limit = 1000;
 
        net->ipv4.sysctl_tcp_fastopen = TFO_CLIENT_ENABLE;
        spin_lock_init(&net->ipv4.tcp_fastopen_ctx_lock);