[NETNS][IPV6] tcp6 - make socket control per namespace

Instead of having a tcp6_socket global to all the namespace, there is
tcp6 socket control per namespace. That is consistent with which
namespace sent a RST and allows to pass the socket to the underlying
function to retrieve the network namespace.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 10 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index b47cce8fea44..7954b4e99c4f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -69,9 +69,6 @@
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
 
-/* Socket used for sending RSTs and ACKs */
-static struct socket *tcp6_socket;
-
 static void     tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb);
 static void     tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req);
 static void     tcp_v6_send_check(struct sock *sk, int len,
@@ -1075,10 +1072,11 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
          * Underlying function will use this to retrieve the network
          * namespace
          */
-        if (!ip6_dst_lookup(tcp6_socket->sk, &buff->dst, &fl)) {
+        if (!ip6_dst_lookup(init_net.ipv6.tcp_sk, &buff->dst, &fl)) {
 
                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
-                        ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
+                        ip6_xmit(init_net.ipv6.tcp_sk,
+                                 buff, &fl, NULL, 0);
                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
                         TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
                         return;
@@ -1175,9 +1173,10 @@ static void tcp_v6_send_ack(struct tcp_timewait_sock *tw,
         fl.fl_ip_sport = t1->source;
         security_skb_classify_flow(skb, &fl);
 
-        if (!ip6_dst_lookup(tcp6_socket->sk, &buff->dst, &fl)) {
+        if (!ip6_dst_lookup(init_net.ipv6.tcp_sk, &buff->dst, &fl)) {
                 if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {
-                        ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);
+                        ip6_xmit(init_net.ipv6.tcp_sk,
+                                 buff, &fl, NULL, 0);
                         TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
                         return;
                 }
@@ -2198,6 +2197,31 @@ static struct inet_protosw tcpv6_protosw = {
                                 INET_PROTOSW_ICSK,
 };
 
+static int tcpv6_net_init(struct net *net)
+{
+        int err;
+        struct socket *sock;
+        struct sock *sk;
+
+        err = inet_csk_ctl_sock_create(&sock, PF_INET6, SOCK_RAW, IPPROTO_TCP);
+        if (err)
+                return err;
+
+        net->ipv6.tcp_sk = sk = sock->sk;
+        sk_change_net(sk, net);
+        return err;
+}
+
+static void tcpv6_net_exit(struct net *net)
+{
+        sk_release_kernel(net->ipv6.tcp_sk);
+}
+
+static struct pernet_operations tcpv6_net_ops = {
+        .init = tcpv6_net_init,
+        .exit = tcpv6_net_exit,
+};
+
 int __init tcpv6_init(void)
 {
         int ret;
@@ -2211,8 +2235,7 @@ int __init tcpv6_init(void)
         if (ret)
                 goto out_tcpv6_protocol;
 
-        ret = inet_csk_ctl_sock_create(&tcp6_socket, PF_INET6,
-                                       SOCK_RAW, IPPROTO_TCP);
+        ret = register_pernet_subsys(&tcpv6_net_ops);
         if (ret)
                 goto out_tcpv6_protosw;
 out:
@@ -2227,7 +2250,7 @@ out_tcpv6_protosw:
 
 void tcpv6_exit(void)
 {
-        sock_release(tcp6_socket);
+        unregister_pernet_subsys(&tcpv6_net_ops);
         inet6_unregister_protosw(&tcpv6_protosw);
         inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
 }