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

Change ndisc_recv_ns() to return a drop reason.

For the moment, return PKT_TOO_SMALL, NOT_SPECIFIED
or SKB_CONSUMED.

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 9548b5a44714f98975a8b7194bc81cbb0f72697f..039722f83c668ad59eb63ffde98e18ad8947bdcc 100644 (file)
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -783,7 +783,7 @@ void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
        ndisc_ops_update(dev, neigh, flags, icmp6_type, ndopts);
 }
 
-static void ndisc_recv_ns(struct sk_buff *skb)
+static enum skb_drop_reason ndisc_recv_ns(struct sk_buff *skb)
 {
        struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb);
        const struct in6_addr *saddr = &ipv6_hdr(skb)->saddr;
@@ -797,18 +797,17 @@ static void ndisc_recv_ns(struct sk_buff *skb)
        struct inet6_dev *idev = NULL;
        struct neighbour *neigh;
        int dad = ipv6_addr_any(saddr);
-       bool inc;
        int is_router = -1;
+       SKB_DR(reason);
        u64 nonce = 0;
+       bool inc;
 
-       if (skb->len < sizeof(struct nd_msg)) {
-               ND_PRINTK(2, warn, "NS: 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, "NS: multicast target address\n");
-               return;
+               return reason;
        }
 
        /*
@@ -817,12 +816,12 @@ static void ndisc_recv_ns(struct sk_buff *skb)
         */
        if (dad && !ipv6_addr_is_solict_mult(daddr)) {
                ND_PRINTK(2, warn, "NS: bad DAD packet (wrong destination)\n");
-               return;
+               return reason;
        }
 
        if (!ndisc_parse_options(dev, msg->opt, ndoptlen, &ndopts)) {
                ND_PRINTK(2, warn, "NS: invalid ND options\n");
-               return;
+               return reason;
        }
 
        if (ndopts.nd_opts_src_lladdr) {
@@ -830,7 +829,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
                if (!lladdr) {
                        ND_PRINTK(2, warn,
                                  "NS: invalid link-layer address length\n");
-                       return;
+                       return reason;
                }
 
                /* RFC2461 7.1.1:
@@ -841,7 +840,7 @@ static void ndisc_recv_ns(struct sk_buff *skb)
                if (dad) {
                        ND_PRINTK(2, warn,
                                  "NS: bad DAD packet (link-layer address option)\n");
-                       return;
+                       return reason;
                }
        }
        if (ndopts.nd_opts_nonce && ndopts.nd_opts_nonce->nd_opt_len == 1)
@@ -869,7 +868,7 @@ have_ifp:
                                 * so fail our DAD process
                                 */
                                addrconf_dad_failure(skb, ifp);
-                               return;
+                               return reason;
                        } else {
                                /*
                                 * This is not a dad solicitation.
@@ -901,7 +900,7 @@ have_ifp:
                idev = in6_dev_get(dev);
                if (!idev) {
                        /* XXX: count this drop? */
-                       return;
+                       return reason;
                }
 
                if (ipv6_chk_acast_addr(net, dev, &msg->target) ||
@@ -958,6 +957,7 @@ have_ifp:
                              true, (ifp != NULL && inc), inc);
                if (neigh)
                        neigh_release(neigh);
+               reason = SKB_CONSUMED;
        }
 
 out:
@@ -965,6 +965,7 @@ out:
                in6_ifa_put(ifp);
        else
                in6_dev_put(idev);
+       return reason;
 }
 
 static int accept_untracked_na(struct net_device *dev, struct in6_addr *saddr)
@@ -1781,8 +1782,9 @@ release:
 
 static void pndisc_redo(struct sk_buff *skb)
 {
-       ndisc_recv_ns(skb);
-       kfree_skb(skb);
+       enum skb_drop_reason reason = ndisc_recv_ns(skb);
+
+       kfree_skb_reason(skb, reason);
 }
 
 static int ndisc_is_multicast(const void *pkey)
@@ -1834,7 +1836,7 @@ enum skb_drop_reason ndisc_rcv(struct sk_buff *skb)
        switch (msg->icmph.icmp6_type) {
        case NDISC_NEIGHBOUR_SOLICITATION:
                memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb));
-               ndisc_recv_ns(skb);
+               reason = ndisc_recv_ns(skb);
                break;
 
        case NDISC_NEIGHBOUR_ADVERTISEMENT: