tcp: Namespace-ify sysctl_tcp_rmem and sysctl_tcp_wmem

Note that when a new netns is created, it inherits its
sysctl_tcp_rmem and sysctl_tcp_wmem from initial netns.

This change is needed so that we can refine TCP rcvbuf autotuning,
to take RTT into consideration.

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

1 files changed, 8 insertions, 6 deletions

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b54ee09cbcf7..9ceaa1fdc3ab 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -320,7 +320,7 @@ static void tcp_sndbuf_expand(struct sock *sk)
         sndmem *= nr_segs * per_mss;
 
         if (sk->sk_sndbuf < sndmem)
-                sk->sk_sndbuf = min(sndmem, sysctl_tcp_wmem[2]);
+                sk->sk_sndbuf = min(sndmem, sock_net(sk)->ipv4.sysctl_tcp_wmem[2]);
 }
 
 /* 2. Tuning advertised window (window_clamp, rcv_ssthresh)
@@ -354,7 +354,7 @@ static int __tcp_grow_window(const struct sock *sk, const struct sk_buff *skb)
         struct tcp_sock *tp = tcp_sk(sk);
         /* Optimize this! */
         int truesize = tcp_win_from_space(sk, skb->truesize) >> 1;
-        int window = tcp_win_from_space(sk, sysctl_tcp_rmem[2]) >> 1;
+        int window = tcp_win_from_space(sk, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]) >> 1;
 
         while (tp->rcv_ssthresh <= window) {
                 if (truesize <= skb->len)
@@ -409,7 +409,7 @@ static void tcp_fixup_rcvbuf(struct sock *sk)
                 rcvmem <<= 2;
 
         if (sk->sk_rcvbuf < rcvmem)
-                sk->sk_rcvbuf = min(rcvmem, sysctl_tcp_rmem[2]);
+                sk->sk_rcvbuf = min(rcvmem, sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
 }
 
 /* 4. Try to fixup all. It is made immediately after connection enters
@@ -457,15 +457,16 @@ static void tcp_clamp_window(struct sock *sk)
 {
         struct tcp_sock *tp = tcp_sk(sk);
         struct inet_connection_sock *icsk = inet_csk(sk);
+        struct net *net = sock_net(sk);
 
         icsk->icsk_ack.quick = 0;
 
-        if (sk->sk_rcvbuf < sysctl_tcp_rmem[2] &&
+        if (sk->sk_rcvbuf < net->ipv4.sysctl_tcp_rmem[2] &&
             !(sk->sk_userlocks & SOCK_RCVBUF_LOCK) &&
             !tcp_under_memory_pressure(sk) &&
             sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)) {
                 sk->sk_rcvbuf = min(atomic_read(&sk->sk_rmem_alloc),
-                                    sysctl_tcp_rmem[2]);
+                                    net->ipv4.sysctl_tcp_rmem[2]);
         }
         if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf)
                 tp->rcv_ssthresh = min(tp->window_clamp, 2U * tp->advmss);
@@ -623,7 +624,8 @@ void tcp_rcv_space_adjust(struct sock *sk)
                 while (tcp_win_from_space(sk, rcvmem) < tp->advmss)
                         rcvmem += 128;
 
-                rcvbuf = min(rcvwin / tp->advmss * rcvmem, sysctl_tcp_rmem[2]);
+                rcvbuf = min(rcvwin / tp->advmss * rcvmem,
+                             sock_net(sk)->ipv4.sysctl_tcp_rmem[2]);
                 if (rcvbuf > sk->sk_rcvbuf) {
                         sk->sk_rcvbuf = rcvbuf;