3 files changed, 53 insertions, 14 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 5b2d63ed793e..a4f6263fddca 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -493,7 +493,8 @@ int ip6_forward(struct sk_buff *skb)
         if (mtu < IPV6_MIN_MTU)
                 mtu = IPV6_MIN_MTU;
 
-        if (skb->len > mtu && !skb_is_gso(skb)) {
+        if ((!skb->local_df && skb->len > mtu && !skb_is_gso(skb)) ||
+            (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) {
                 /* Again, force OUTPUT device used as source address */
                 skb->dev = dst->dev;
                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
@@ -636,7 +637,9 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
         /* We must not fragment if the socket is set to force MTU discovery
          * or if the skb it not generated by a local socket.
          */
-        if (unlikely(!skb->local_df && skb->len > mtu)) {
+        if (unlikely(!skb->local_df && skb->len > mtu) ||
+                     (IP6CB(skb)->frag_max_size &&
+                      IP6CB(skb)->frag_max_size > mtu)) {
                 if (skb->sk && dst_allfrag(skb_dst(skb)))
                         sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
 
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 4794f96cf2e0..521ddca876f8 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -153,10 +153,10 @@ static unsigned int ipv6_helper(unsigned int hooknum,
         const struct nf_conn_help *help;
         const struct nf_conntrack_helper *helper;
         enum ip_conntrack_info ctinfo;
-        unsigned int ret, protoff;
-        unsigned int extoff = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
-        unsigned char pnum = ipv6_hdr(skb)->nexthdr;
-
+        unsigned int ret;
+        __be16 frag_off;
+        int protoff;
+        u8 nexthdr;
 
         /* This is where we call the helper: as the packet goes out. */
         ct = nf_ct_get(skb, &ctinfo);
@@ -171,9 +171,10 @@ static unsigned int ipv6_helper(unsigned int hooknum,
         if (!helper)
                 return NF_ACCEPT;
 
-        protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
-                                         skb->len - extoff);
-        if (protoff > skb->len || pnum == NEXTHDR_FRAGMENT) {
+        nexthdr = ipv6_hdr(skb)->nexthdr;
+        protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
+                                   &frag_off);
+        if (protoff < 0 || (frag_off & htons(~0x7)) != 0) {
                 pr_debug("proto header not found\n");
                 return NF_ACCEPT;
         }
@@ -199,9 +200,14 @@ static unsigned int ipv6_confirm(unsigned int hooknum,
 static unsigned int __ipv6_conntrack_in(struct net *net,
                                         unsigned int hooknum,
                                         struct sk_buff *skb,
+                                        const struct net_device *in,
+                                        const struct net_device *out,
                                         int (*okfn)(struct sk_buff *))
 {
         struct sk_buff *reasm = skb->nfct_reasm;
+        const struct nf_conn_help *help;
+        struct nf_conn *ct;
+        enum ip_conntrack_info ctinfo;
 
         /* This packet is fragmented and has reassembled packet. */
         if (reasm) {
@@ -213,6 +219,23 @@ static unsigned int __ipv6_conntrack_in(struct net *net,
                         if (ret != NF_ACCEPT)
                                 return ret;
                 }
+
+                /* Conntrack helpers need the entire reassembled packet in the
+                 * POST_ROUTING hook.
+                 */
+                ct = nf_ct_get(reasm, &ctinfo);
+                if (ct != NULL && !nf_ct_is_untracked(ct)) {
+                        help = nfct_help(ct);
+                        if (help && help->helper) {
+                                nf_conntrack_get_reasm(skb);
+                                NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm,
+                                               (struct net_device *)in,
+                                               (struct net_device *)out,
+                                               okfn, NF_IP6_PRI_CONNTRACK + 1);
+                                return NF_DROP_ERR(-ECANCELED);
+                        }
+                }
+
                 nf_conntrack_get(reasm->nfct);
                 skb->nfct = reasm->nfct;
                 skb->nfctinfo = reasm->nfctinfo;
@@ -228,7 +251,7 @@ static unsigned int ipv6_conntrack_in(unsigned int hooknum,
                                       const struct net_device *out,
                                       int (*okfn)(struct sk_buff *))
 {
-        return __ipv6_conntrack_in(dev_net(in), hooknum, skb, okfn);
+        return __ipv6_conntrack_in(dev_net(in), hooknum, skb, in, out, okfn);
 }
 
 static unsigned int ipv6_conntrack_local(unsigned int hooknum,
@@ -242,7 +265,7 @@ static unsigned int ipv6_conntrack_local(unsigned int hooknum,
                 net_notice_ratelimited("ipv6_conntrack_local: packet too short\n");
                 return NF_ACCEPT;
         }
-        return __ipv6_conntrack_in(dev_net(out), hooknum, skb, okfn);
+        return __ipv6_conntrack_in(dev_net(out), hooknum, skb, in, out, okfn);
 }
 
 static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index c9c78c2e666b..f94fb3ac2a79 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -190,6 +190,7 @@ static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
                              const struct frag_hdr *fhdr, int nhoff)
 {
         struct sk_buff *prev, *next;
+        unsigned int payload_len;
         int offset, end;
 
         if (fq->q.last_in & INET_FRAG_COMPLETE) {
@@ -197,8 +198,10 @@ static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
                 goto err;
         }
 
+        payload_len = ntohs(ipv6_hdr(skb)->payload_len);
+
         offset = ntohs(fhdr->frag_off) & ~0x7;
-        end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
+        end = offset + (payload_len -
                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 
         if ((unsigned int)end > IPV6_MAXPLEN) {
@@ -307,6 +310,8 @@ found:
         skb->dev = NULL;
         fq->q.stamp = skb->tstamp;
         fq->q.meat += skb->len;
+        if (payload_len > fq->q.max_size)
+                fq->q.max_size = payload_len;
         atomic_add(skb->truesize, &nf_init_frags.mem);
 
         /* The first fragment.
@@ -412,10 +417,12 @@ nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
         }
         atomic_sub(head->truesize, &nf_init_frags.mem);
 
+        head->local_df = 1;
         head->next = NULL;
         head->dev = dev;
         head->tstamp = fq->q.stamp;
         ipv6_hdr(head)->payload_len = htons(payload_len);
+        IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
 
         /* Yes, and fold redundant checksum back. 8) */
         if (head->ip_summed == CHECKSUM_COMPLETE)
@@ -592,6 +599,7 @@ void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
                         int (*okfn)(struct sk_buff *))
 {
         struct sk_buff *s, *s2;
+        unsigned int ret = 0;
 
         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
                 nf_conntrack_put_reasm(s->nfct_reasm);
@@ -601,8 +609,13 @@ void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
                 s2 = s->next;
                 s->next = NULL;
 
-                NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, s, in, out, okfn,
-                               NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
+                if (ret != -ECANCELED)
+                        ret = NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, s,
+                                             in, out, okfn,
+                                             NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
+                else
+                        kfree_skb(s);
+
                 s = s2;
         }
         nf_conntrack_put_reasm(skb);