ipv6: icmp6: add drop reason support to ndisc_recv_na()

Change ndisc_recv_na() to return a drop reason.

For the moment, return PKT_TOO_SMALL, NOT_SPECIFIED
or SKB_CONSUMED. More reasons are added later.

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

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 039722f..9354cb3 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -987,7 +987,7 @@ static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
        }
 }
 
-static void ndisc_recv_na(struct sk_buff *skb)
+static enum skb_drop_reason ndisc_recv_na(struct sk_buff *skb)
 {
        struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
        struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
@@ -1000,22 +1000,21 @@ static void ndisc_recv_na(struct sk_buff *skb)
        struct inet6_dev *idev = __in6_dev_get(dev);
        struct inet6_ifaddr *ifp;
        struct neighbour *neigh;
+       SKB_DR(reason);
        u8 new_state;
 
-       if (skb->len < sizeof(struct nd_msg)) {
-               ND_PRINTK(2, warn, "NA: packet too short\n");
-               return;
-       }
+       if (skb->len < sizeof(struct nd_msg))
+               return SKB_DROP_REASON_PKT_TOO_SMALL;
 
        if (ipv6_addr_is_multicast(&msg->target)) {
                ND_PRINTK(2, warn, "NA: target address is multicast\n");
-               return;
+               return reason;
        }
 
        if (ipv6_addr_is_multicast(daddr) &&
            msg->icmph.icmp6_solicited) {
                ND_PRINTK(2, warn, "NA: solicited NA is multicasted\n");
-               return;
+               return reason;
        }
 
        /* For some 802.11 wireless deployments (and possibly other networks),
@@ -1025,18 +1024,18 @@ static void ndisc_recv_na(struct sk_buff *skb)
         */
        if (!msg->icmph.icmp6_solicited && idev &&
            idev->cnf.drop_unsolicited_na)
-               return;
+               return reason;
 
        if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
                ND_PRINTK(2, warn, "NS: invalid ND option\n");
-               return;
+               return reason;
        }
        if (ndopts.nd_opts_tgt_lladdr) {
                lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev);
                if (!lladdr) {
                        ND_PRINTK(2, warn,
                                  "NA: invalid link-layer address length\n");
-                       return;
+                       return reason;
                }
        }
        ifp = ipv6_get_ifaddr(dev_net(dev), &msg->target, dev, 1);
@@ -1044,7 +1043,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
                if (skb->pkt_type != PACKET_LOOPBACK
                    && (ifp->flags & IFA_F_TENTATIVE)) {
                                addrconf_dad_failure(skb, ifp);
-                               return;
+                               return reason;
                }
                /* What should we make now? The advertisement
                   is invalid, but ndisc specs say nothing
@@ -1060,7 +1059,7 @@ static void ndisc_recv_na(struct sk_buff *skb)
                                  "NA: %pM advertised our address %pI6c on %s!\n",
                                  eth_hdr(skb)->h_source, &ifp->addr, ifp->idev->dev->name);
                in6_ifa_put(ifp);
-               return;
+               return reason;
        }
 
        neigh = neigh_lookup(&nd_tbl, &msg->target, dev);
@@ -1121,10 +1120,11 @@ static void ndisc_recv_na(struct sk_buff *skb)
                         */
                        rt6_clean_tohost(dev_net(dev),  saddr);
                }
-
+               reason = SKB_CONSUMED;
 out:
                neigh_release(neigh);
        }
+       return reason;
 }
 
 static void ndisc_recv_rs(struct sk_buff *skb)
@@ -1840,7 +1840,7 @@ enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
                break;
 
        case NDISC_NEIGHBOUR_ADVERTISEMENT:
-               ndisc_recv_na(skb);
+               reason = ndisc_recv_na(skb);
                break;
 
        case NDISC_ROUTER_SOLICITATION: