ipv4: add a sock pointer to dst->output() path.

In the dst->output() path for ipv4, the code assumes the skb it has to
transmit is attached to an inet socket, specifically via
ip_mc_output() : The sk_mc_loop() test triggers a WARN_ON() when the
provider of the packet is an AF_PACKET socket.

The dst->output() method gets an additional 'struct sock *sk'
parameter. This needs a cascade of changes so that this parameter can
be propagated from vxlan to final consumer.

Fixes: 8f646c922d55 ("vxlan: keep original skb ownership")
Reported-by: lucien xin <lucien.xin@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

19 files changed, 74 insertions, 46 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index c55e316373a1..82355d5d155a 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -1755,8 +1755,8 @@ int vxlan_xmit_skb(struct vxlan_sock *vs,
         if (err)
                 return err;
 
-        return iptunnel_xmit(rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df,
-                             false);
+        return iptunnel_xmit(vs->sock->sk, rt, skb, src, dst, IPPROTO_UDP,
+                             tos, ttl, df, false);
 }
 EXPORT_SYMBOL_GPL(vxlan_xmit_skb);
 
diff --git a/include/net/dst.h b/include/net/dst.h
index 46ed958e0c6e..71c60f42be48 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -45,7 +45,7 @@ struct dst_entry {
         void                    *__pad1;
 #endif
         int                     (*input)(struct sk_buff *);
-        int                     (*output)(struct sk_buff *);
+        int                     (*output)(struct sock *sk, struct sk_buff *skb);
 
         unsigned short          flags;
 #define DST_HOST                0x0001
@@ -367,7 +367,11 @@ static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
         return child;
 }
 
-int dst_discard(struct sk_buff *skb);
+int dst_discard_sk(struct sock *sk, struct sk_buff *skb);
+static inline int dst_discard(struct sk_buff *skb)
+{
+        return dst_discard_sk(skb->sk, skb);
+}
 void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
                 int initial_obsolete, unsigned short flags);
 void __dst_free(struct dst_entry *dst);
@@ -449,9 +453,13 @@ static inline void dst_set_expires(struct dst_entry *dst, int timeout)
 }
 
 /* Output packet to network from transport.  */
+static inline int dst_output_sk(struct sock *sk, struct sk_buff *skb)
+{
+        return skb_dst(skb)->output(sk, skb);
+}
 static inline int dst_output(struct sk_buff *skb)
 {
-        return skb_dst(skb)->output(skb);
+        return dst_output_sk(skb->sk, skb);
 }
 
 /* Input packet from network to transport.  */
diff --git a/include/net/ip.h b/include/net/ip.h
index 77e73d293e09..3ec2b0fb9d83 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -104,13 +104,18 @@ int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
            struct net_device *orig_dev);
 int ip_local_deliver(struct sk_buff *skb);
 int ip_mr_input(struct sk_buff *skb);
-int ip_output(struct sk_buff *skb);
-int ip_mc_output(struct sk_buff *skb);
+int ip_output(struct sock *sk, struct sk_buff *skb);
+int ip_mc_output(struct sock *sk, struct sk_buff *skb);
 int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
 int ip_do_nat(struct sk_buff *skb);
 void ip_send_check(struct iphdr *ip);
 int __ip_local_out(struct sk_buff *skb);
-int ip_local_out(struct sk_buff *skb);
+int ip_local_out_sk(struct sock *sk, struct sk_buff *skb);
+static inline int ip_local_out(struct sk_buff *skb)
+{
+        return ip_local_out_sk(skb->sk, skb);
+}
+
 int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
 void ip_init(void);
 int ip_append_data(struct sock *sk, struct flowi4 *fl4,
diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index e77c10405d51..a4daf9eb8562 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -153,7 +153,7 @@ static inline u8 ip_tunnel_ecn_encap(u8 tos, const struct iphdr *iph,
 }
 
 int iptunnel_pull_header(struct sk_buff *skb, int hdr_len, __be16 inner_proto);
-int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
+int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
                   __be32 src, __be32 dst, __u8 proto,
                   __u8 tos, __u8 ttl, __be16 df, bool xnet);
 
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 4f541f11ce63..d640925bc454 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -731,7 +731,7 @@ struct dst_entry *ip6_blackhole_route(struct net *net,
  *      skb processing functions
  */
 
-int ip6_output(struct sk_buff *skb);
+int ip6_output(struct sock *sk, struct sk_buff *skb);
 int ip6_forward(struct sk_buff *skb);
 int ip6_input(struct sk_buff *skb);
 int ip6_mc_input(struct sk_buff *skb);
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 32682ae47b3f..116e9c7e19cb 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -333,7 +333,7 @@ struct xfrm_state_afinfo {
                                                 const xfrm_address_t *saddr);
         int                     (*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
         int                     (*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
-        int                     (*output)(struct sk_buff *skb);
+        int                     (*output)(struct sock *sk, struct sk_buff *skb);
         int                     (*output_finish)(struct sk_buff *skb);
         int                     (*extract_input)(struct xfrm_state *x,
                                                  struct sk_buff *skb);
@@ -1540,7 +1540,7 @@ static inline int xfrm4_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi)
 
 int xfrm4_extract_output(struct xfrm_state *x, struct sk_buff *skb);
 int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
-int xfrm4_output(struct sk_buff *skb);
+int xfrm4_output(struct sock *sk, struct sk_buff *skb);
 int xfrm4_output_finish(struct sk_buff *skb);
 int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err);
 int xfrm4_protocol_register(struct xfrm4_protocol *handler, unsigned char protocol);
@@ -1565,7 +1565,7 @@ __be32 xfrm6_tunnel_alloc_spi(struct net *net, xfrm_address_t *saddr);
 __be32 xfrm6_tunnel_spi_lookup(struct net *net, const xfrm_address_t *saddr);
 int xfrm6_extract_output(struct xfrm_state *x, struct sk_buff *skb);
 int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb);
-int xfrm6_output(struct sk_buff *skb);
+int xfrm6_output(struct sock *sk, struct sk_buff *skb);
 int xfrm6_output_finish(struct sk_buff *skb);
 int xfrm6_find_1stfragopt(struct xfrm_state *x, struct sk_buff *skb,
                           u8 **prevhdr);
diff --git a/net/core/dst.c b/net/core/dst.c
index ca4231ec7347..80d6286c8b62 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -142,12 +142,12 @@ loop:
         mutex_unlock(&dst_gc_mutex);
 }
 
-int dst_discard(struct sk_buff *skb)
+int dst_discard_sk(struct sock *sk, struct sk_buff *skb)
 {
         kfree_skb(skb);
         return 0;
 }
-EXPORT_SYMBOL(dst_discard);
+EXPORT_SYMBOL(dst_discard_sk);
 
 const u32 dst_default_metrics[RTAX_MAX + 1] = {
         /* This initializer is needed to force linker to place this variable
@@ -184,7 +184,7 @@ void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
         dst->xfrm = NULL;
 #endif
         dst->input = dst_discard;
-        dst->output = dst_discard;
+        dst->output = dst_discard_sk;
         dst->error = 0;
         dst->obsolete = initial_obsolete;
         dst->header_len = 0;
@@ -209,8 +209,10 @@ static void ___dst_free(struct dst_entry *dst)
         /* The first case (dev==NULL) is required, when
            protocol module is unloaded.
          */
-        if (dst->dev == NULL || !(dst->dev->flags&IFF_UP))
-                dst->input = dst->output = dst_discard;
+        if (dst->dev == NULL || !(dst->dev->flags&IFF_UP)) {
+                dst->input = dst_discard;
+                dst->output = dst_discard_sk;
+        }
         dst->obsolete = DST_OBSOLETE_DEAD;
 }
 
@@ -361,7 +363,8 @@ static void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
                 return;
 
         if (!unregister) {
-                dst->input = dst->output = dst_discard;
+                dst->input = dst_discard;
+                dst->output = dst_discard_sk;
         } else {
                 dst->dev = dev_net(dst->dev)->loopback_dev;
                 dev_hold(dst->dev);
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index ce0cbbfe0f43..daccc4a36d80 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -752,7 +752,7 @@ static int dn_to_neigh_output(struct sk_buff *skb)
         return n->output(n, skb);
 }
 
-static int dn_output(struct sk_buff *skb)
+static int dn_output(struct sock *sk, struct sk_buff *skb)
 {
         struct dst_entry *dst = skb_dst(skb);
         struct dn_route *rt = (struct dn_route *)dst;
@@ -838,6 +838,18 @@ drop:
  * Used to catch bugs. This should never normally get
  * called.
  */
+static int dn_rt_bug_sk(struct sock *sk, struct sk_buff *skb)
+{
+        struct dn_skb_cb *cb = DN_SKB_CB(skb);
+
+        net_dbg_ratelimited("dn_rt_bug: skb from:%04x to:%04x\n",
+                            le16_to_cpu(cb->src), le16_to_cpu(cb->dst));
+
+        kfree_skb(skb);
+
+        return NET_RX_DROP;
+}
+
 static int dn_rt_bug(struct sk_buff *skb)
 {
         struct dn_skb_cb *cb = DN_SKB_CB(skb);
@@ -1463,7 +1475,7 @@ make_route:
 
         rt->n = neigh;
         rt->dst.lastuse = jiffies;
-        rt->dst.output = dn_rt_bug;
+        rt->dst.output = dn_rt_bug_sk;
         switch (res.type) {
         case RTN_UNICAST:
                 rt->dst.input = dn_forward;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 7ad68b860935..1cbeba5edff9 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -101,17 +101,17 @@ int __ip_local_out(struct sk_buff *skb)
                        skb_dst(skb)->dev, dst_output);
 }
 
-int ip_local_out(struct sk_buff *skb)
+int ip_local_out_sk(struct sock *sk, struct sk_buff *skb)
 {
         int err;
 
         err = __ip_local_out(skb);
         if (likely(err == 1))
-                err = dst_output(skb);
+                err = dst_output_sk(sk, skb);
 
         return err;
 }
-EXPORT_SYMBOL_GPL(ip_local_out);
+EXPORT_SYMBOL_GPL(ip_local_out_sk);
 
 static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
 {
@@ -226,9 +226,8 @@ static int ip_finish_output(struct sk_buff *skb)
                 return ip_finish_output2(skb);
 }
 
-int ip_mc_output(struct sk_buff *skb)
+int ip_mc_output(struct sock *sk, struct sk_buff *skb)
 {
-        struct sock *sk = skb->sk;
         struct rtable *rt = skb_rtable(skb);
         struct net_device *dev = rt->dst.dev;
 
@@ -287,7 +286,7 @@ int ip_mc_output(struct sk_buff *skb)
                             !(IPCB(skb)->flags & IPSKB_REROUTED));
 }
 
-int ip_output(struct sk_buff *skb)
+int ip_output(struct sock *sk, struct sk_buff *skb)
 {
         struct net_device *dev = skb_dst(skb)->dev;
 
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index e77381d1df9a..484d0ce27ef7 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -670,7 +670,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
                 return;
         }
 
-        err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, protocol,
+        err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr, protocol,
                             tos, ttl, df, !net_eq(tunnel->net, dev_net(dev)));
         iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index e0c2b1d2ea4e..bcf206c79005 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -46,7 +46,7 @@
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
 
-int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
+int iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
                   __be32 src, __be32 dst, __u8 proto,
                   __u8 tos, __u8 ttl, __be16 df, bool xnet)
 {
@@ -76,7 +76,7 @@ int iptunnel_xmit(struct rtable *rt, struct sk_buff *skb,
         iph->ttl        =       ttl;
         __ip_select_ident(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);
 
-        err = ip_local_out(skb);
+        err = ip_local_out_sk(sk, skb);
         if (unlikely(net_xmit_eval(err)))
                 pkt_len = 0;
         return pkt_len;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 20a59c388e6e..1485aafcad59 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1129,7 +1129,7 @@ static void ipv4_link_failure(struct sk_buff *skb)
                 dst_set_expires(&rt->dst, 0);
 }
 
-static int ip_rt_bug(struct sk_buff *skb)
+static int ip_rt_bug(struct sock *sk, struct sk_buff *skb)
 {
         pr_debug("%s: %pI4 -> %pI4, %s\n",
                  __func__, &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
@@ -2218,7 +2218,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
 
                 new->__use = 1;
                 new->input = dst_discard;
-                new->output = dst_discard;
+                new->output = dst_discard_sk;
 
                 new->dev = ort->dst.dev;
                 if (new->dev)
diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
index baa0f63731fd..40e701f2e1e0 100644
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -86,7 +86,7 @@ int xfrm4_output_finish(struct sk_buff *skb)
         return xfrm_output(skb);
 }
 
-int xfrm4_output(struct sk_buff *skb)
+int xfrm4_output(struct sock *sk, struct sk_buff *skb)
 {
         struct dst_entry *dst = skb_dst(skb);
         struct xfrm_state *x = dst->xfrm;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 3284d61577c0..40e7581374f7 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -132,7 +132,7 @@ static int ip6_finish_output(struct sk_buff *skb)
                 return ip6_finish_output2(skb);
 }
 
-int ip6_output(struct sk_buff *skb)
+int ip6_output(struct sock *sk, struct sk_buff *skb)
 {
         struct net_device *dev = skb_dst(skb)->dev;
         struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5ea462eacd9f..4011617cca68 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -84,9 +84,9 @@ static void		ip6_dst_ifdown(struct dst_entry *,
 static int               ip6_dst_gc(struct dst_ops *ops);
 
 static int              ip6_pkt_discard(struct sk_buff *skb);
-static int              ip6_pkt_discard_out(struct sk_buff *skb);
+static int              ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb);
 static int              ip6_pkt_prohibit(struct sk_buff *skb);
-static int              ip6_pkt_prohibit_out(struct sk_buff *skb);
+static int              ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb);
 static void             ip6_link_failure(struct sk_buff *skb);
 static void             ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
                                            struct sk_buff *skb, u32 mtu);
@@ -290,7 +290,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = {
                 .obsolete       = DST_OBSOLETE_FORCE_CHK,
                 .error          = -EINVAL,
                 .input          = dst_discard,
-                .output         = dst_discard,
+                .output         = dst_discard_sk,
         },
         .rt6i_flags     = (RTF_REJECT | RTF_NONEXTHOP),
         .rt6i_protocol  = RTPROT_KERNEL,
@@ -1058,7 +1058,7 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 
                 new->__use = 1;
                 new->input = dst_discard;
-                new->output = dst_discard;
+                new->output = dst_discard_sk;
 
                 if (dst_metrics_read_only(&ort->dst))
                         new->_metrics = ort->dst._metrics;
@@ -1577,7 +1577,7 @@ int ip6_route_add(struct fib6_config *cfg)
                 switch (cfg->fc_type) {
                 case RTN_BLACKHOLE:
                         rt->dst.error = -EINVAL;
-                        rt->dst.output = dst_discard;
+                        rt->dst.output = dst_discard_sk;
                         rt->dst.input = dst_discard;
                         break;
                 case RTN_PROHIBIT:
@@ -2129,7 +2129,7 @@ static int ip6_pkt_discard(struct sk_buff *skb)
         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
 }
 
-static int ip6_pkt_discard_out(struct sk_buff *skb)
+static int ip6_pkt_discard_out(struct sock *sk, struct sk_buff *skb)
 {
         skb->dev = skb_dst(skb)->dev;
         return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
@@ -2140,7 +2140,7 @@ static int ip6_pkt_prohibit(struct sk_buff *skb)
         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
 }
 
-static int ip6_pkt_prohibit_out(struct sk_buff *skb)
+static int ip6_pkt_prohibit_out(struct sock *sk, struct sk_buff *skb)
 {
         skb->dev = skb_dst(skb)->dev;
         return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 1693c8d885f0..8da8268d65f8 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -974,8 +974,9 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
                 goto out;
         }
 
-        err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos,
-                            ttl, df, !net_eq(tunnel->net, dev_net(dev)));
+        err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr,
+                            IPPROTO_IPV6, tos, ttl, df,
+                            !net_eq(tunnel->net, dev_net(dev)));
         iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
         return NETDEV_TX_OK;
 
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 6cd625e37706..19ef329bdbf8 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -163,7 +163,7 @@ static int __xfrm6_output(struct sk_buff *skb)
         return x->outer_mode->afinfo->output_finish(skb);
 }
 
-int xfrm6_output(struct sk_buff *skb)
+int xfrm6_output(struct sock *sk, struct sk_buff *skb)
 {
         return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
                        skb_dst(skb)->dev, __xfrm6_output);
diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
index a3d6951602db..ebb6e2442554 100644
--- a/net/openvswitch/vport-gre.c
+++ b/net/openvswitch/vport-gre.c
@@ -174,7 +174,7 @@ static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
 
         skb->local_df = 1;
 
-        return iptunnel_xmit(rt, skb, fl.saddr,
+        return iptunnel_xmit(skb->sk, rt, skb, fl.saddr,
                              OVS_CB(skb)->tun_key->ipv4_dst, IPPROTO_GRE,
                              OVS_CB(skb)->tun_key->ipv4_tos,
                              OVS_CB(skb)->tun_key->ipv4_ttl, df, false);
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index f02f511b7107..c08fbd11ceff 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1842,7 +1842,7 @@ purge_queue:
         xfrm_pol_put(pol);
 }
 
-static int xdst_queue_output(struct sk_buff *skb)
+static int xdst_queue_output(struct sock *sk, struct sk_buff *skb)
 {
         unsigned long sched_next;
         struct dst_entry *dst = skb_dst(skb);