Revert "ipv6: Don't depend on per socket memory for neighbour discovery messages"

This reverts commit 1f324e38870cc09659cf23bc626f1b8869e201f2.

It seems to cause regressions, and in particular the output path
really depends upon there being a socket attached to skb->sk for
checks such as sk_mc_loop(skb->sk) for example.  See ip6_output_finish2().

Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Reported-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 5cb98df966c2..04d31c2fbef1 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -370,12 +370,16 @@ static struct sk_buff *ndisc_alloc_skb(struct net_device *dev,
 {
         int hlen = LL_RESERVED_SPACE(dev);
         int tlen = dev->needed_tailroom;
+        struct sock *sk = dev_net(dev)->ipv6.ndisc_sk;
         struct sk_buff *skb;
+        int err;
 
-        skb = alloc_skb(hlen + sizeof(struct ipv6hdr) + len + tlen, GFP_ATOMIC);
+        skb = sock_alloc_send_skb(sk,
+                                  hlen + sizeof(struct ipv6hdr) + len + tlen,
+                                  1, &err);
         if (!skb) {
-                ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb\n",
-                          __func__);
+                ND_PRINTK(0, err, "ndisc: %s failed to allocate an skb, err=%d\n",
+                          __func__, err);
                 return NULL;
         }