ipv6: do not increment mac header when it's unset

[cascardo/linux.git] / net / ipv6 / icmp.c

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index a4fa840..bd59c34 100644 (file)
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -388,7 +388,8 @@ relookup_failed:
 /*
  *     Send an ICMP message in response to a packet in error
  */
-static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
+static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
+                      const struct in6_addr *force_saddr)
 {
        struct net *net = dev_net(skb->dev);
        struct inet6_dev *idev = NULL;
@@ -475,6 +476,8 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
        memset(&fl6, 0, sizeof(fl6));
        fl6.flowi6_proto = IPPROTO_ICMPV6;
        fl6.daddr = hdr->saddr;
+       if (force_saddr)
+               saddr = force_saddr;
        if (saddr)
                fl6.saddr = *saddr;
        fl6.flowi6_mark = mark;
@@ -502,12 +505,14 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
        else if (!fl6.flowi6_oif)
                fl6.flowi6_oif = np->ucast_oif;
 
+       ipc6.tclass = np->tclass;
+       fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
+
        dst = icmpv6_route_lookup(net, skb, sk, &fl6);
        if (IS_ERR(dst))
                goto out;
 
        ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
-       ipc6.tclass = np->tclass;
        ipc6.dontfrag = np->dontfrag;
        ipc6.opt = NULL;
 
@@ -549,10 +554,75 @@ out:
  */
 void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos)
 {
-       icmp6_send(skb, ICMPV6_PARAMPROB, code, pos);
+       icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL);
        kfree_skb(skb);
 }
 
+/* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
+ * if sufficient data bytes are available
+ * @nhs is the size of the tunnel header(s) :
+ *  Either an IPv4 header for SIT encap
+ *         an IPv4 header + GRE header for GRE encap
+ */
+int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type,
+                              unsigned int data_len)
+{
+       struct in6_addr temp_saddr;
+       struct rt6_info *rt;
+       struct sk_buff *skb2;
+       u32 info = 0;
+
+       if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8))
+               return 1;
+
+       /* RFC 4884 (partial) support for ICMP extensions */
+       if (data_len < 128 || (data_len & 7) || skb->len < data_len)
+               data_len = 0;
+
+       skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC);
+
+       if (!skb2)
+               return 1;
+
+       skb_dst_drop(skb2);
+       skb_pull(skb2, nhs);
+       skb_reset_network_header(skb2);
+
+       rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
+
+       if (rt && rt->dst.dev)
+               skb2->dev = rt->dst.dev;
+
+       ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr);
+
+       if (data_len) {
+               /* RFC 4884 (partial) support :
+                * insert 0 padding at the end, before the extensions
+                */
+               __skb_push(skb2, nhs);
+               skb_reset_network_header(skb2);
+               memmove(skb2->data, skb2->data + nhs, data_len - nhs);
+               memset(skb2->data + data_len - nhs, 0, nhs);
+               /* RFC 4884 4.5 : Length is measured in 64-bit words,
+                * and stored in reserved[0]
+                */
+               info = (data_len/8) << 24;
+       }
+       if (type == ICMP_TIME_EXCEEDED)
+               icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
+                          info, &temp_saddr);
+       else
+               icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH,
+                          info, &temp_saddr);
+       if (rt)
+               ip6_rt_put(rt);
+
+       kfree_skb(skb2);
+
+       return 0;
+}
+EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach);
+
 static void icmpv6_echo_reply(struct sk_buff *skb)
 {
        struct net *net = dev_net(skb->dev);
@@ -585,7 +655,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
        fl6.daddr = ipv6_hdr(skb)->saddr;
        if (saddr)
                fl6.saddr = *saddr;
-       fl6.flowi6_oif = l3mdev_fib_oif(skb->dev);
+       fl6.flowi6_oif = skb->dev->ifindex;
        fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY;
        fl6.flowi6_mark = mark;
        security_skb_classify_flow(skb, flowi6_to_flowi(&fl6));