net: make sock diag per-namespace

Before this patch sock_diag works for init_net only and dumps
information about sockets from all namespaces.

This patch expands sock_diag for all name-spaces.
It creates a netlink kernel socket for each netns and filters
data during dumping.

v2: filter accoding with netns in all places
    remove an unused variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/net/ipv4/udp_diag.c b/net/ipv4/udp_diag.c
index a7f86a3cd502..16d0960062be 100644
--- a/net/ipv4/udp_diag.c
+++ b/net/ipv4/udp_diag.c
@@ -34,15 +34,16 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
         int err = -EINVAL;
         struct sock *sk;
         struct sk_buff *rep;
+        struct net *net = sock_net(in_skb->sk);
 
         if (req->sdiag_family == AF_INET)
-                sk = __udp4_lib_lookup(&init_net,
+                sk = __udp4_lib_lookup(net,
                                 req->id.idiag_src[0], req->id.idiag_sport,
                                 req->id.idiag_dst[0], req->id.idiag_dport,
                                 req->id.idiag_if, tbl);
 #if IS_ENABLED(CONFIG_IPV6)
         else if (req->sdiag_family == AF_INET6)
-                sk = __udp6_lib_lookup(&init_net,
+                sk = __udp6_lib_lookup(net,
                                 (struct in6_addr *)req->id.idiag_src,
                                 req->id.idiag_sport,
                                 (struct in6_addr *)req->id.idiag_dst,
@@ -75,7 +76,7 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
                 kfree_skb(rep);
                 goto out;
         }
-        err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
+        err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).pid,
                               MSG_DONTWAIT);
         if (err > 0)
                 err = 0;
@@ -90,6 +91,7 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlin
                 struct inet_diag_req_v2 *r, struct nlattr *bc)
 {
         int num, s_num, slot, s_slot;
+        struct net *net = sock_net(skb->sk);
 
         s_slot = cb->args[0];
         num = s_num = cb->args[1];
@@ -106,6 +108,8 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb, struct netlin
                 sk_nulls_for_each(sk, node, &hslot->head) {
                         struct inet_sock *inet = inet_sk(sk);
 
+                        if (!net_eq(sock_net(sk), net))
+                                continue;
                         if (num < s_num)
                                 goto next;
                         if (!(r->idiag_states & (1 << sk->sk_state)))