1 files changed, 41 insertions, 25 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index e6f931997996..ef02b26ccf81 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -321,6 +321,27 @@ static inline int ip6_forward_finish(struct sk_buff *skb)
         return dst_output(skb);
 }
 
+static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
+{
+        unsigned int mtu;
+        struct inet6_dev *idev;
+
+        if (dst_metric_locked(dst, RTAX_MTU)) {
+                mtu = dst_metric_raw(dst, RTAX_MTU);
+                if (mtu)
+                        return mtu;
+        }
+
+        mtu = IPV6_MIN_MTU;
+        rcu_read_lock();
+        idev = __in6_dev_get(dst->dev);
+        if (idev)
+                mtu = idev->cnf.mtu6;
+        rcu_read_unlock();
+
+        return mtu;
+}
+
 int ip6_forward(struct sk_buff *skb)
 {
         struct dst_entry *dst = skb_dst(skb);
@@ -336,7 +357,8 @@ int ip6_forward(struct sk_buff *skb)
                 goto drop;
 
         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
-                IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_INDISCARDS);
                 goto drop;
         }
 
@@ -370,8 +392,8 @@ int ip6_forward(struct sk_buff *skb)
                 /* Force OUTPUT device used as source address */
                 skb->dev = dst->dev;
                 icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0);
-                IP6_INC_STATS_BH(net,
-                                 ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_INHDRERRORS);
 
                 kfree_skb(skb);
                 return -ETIMEDOUT;
@@ -384,14 +406,15 @@ int ip6_forward(struct sk_buff *skb)
                 if (proxied > 0)
                         return ip6_input(skb);
                 else if (proxied < 0) {
-                        IP6_INC_STATS(net, ip6_dst_idev(dst),
-                                      IPSTATS_MIB_INDISCARDS);
+                        IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                         IPSTATS_MIB_INDISCARDS);
                         goto drop;
                 }
         }
 
         if (!xfrm6_route_forward(skb)) {
-                IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_INDISCARDS);
                 goto drop;
         }
         dst = skb_dst(skb);
@@ -439,7 +462,7 @@ int ip6_forward(struct sk_buff *skb)
                 }
         }
 
-        mtu = dst_mtu(dst);
+        mtu = ip6_dst_mtu_forward(dst);
         if (mtu < IPV6_MIN_MTU)
                 mtu = IPV6_MIN_MTU;
 
@@ -448,16 +471,17 @@ int ip6_forward(struct sk_buff *skb)
                 /* Again, force OUTPUT device used as source address */
                 skb->dev = dst->dev;
                 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
-                IP6_INC_STATS_BH(net,
-                                 ip6_dst_idev(dst), IPSTATS_MIB_INTOOBIGERRORS);
-                IP6_INC_STATS_BH(net,
-                                 ip6_dst_idev(dst), IPSTATS_MIB_FRAGFAILS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_INTOOBIGERRORS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_FRAGFAILS);
                 kfree_skb(skb);
                 return -EMSGSIZE;
         }
 
         if (skb_cow(skb, dst->dev->hard_header_len)) {
-                IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTDISCARDS);
+                IP6_INC_STATS_BH(net, ip6_dst_idev(dst),
+                                 IPSTATS_MIB_OUTDISCARDS);
                 goto drop;
         }
 
@@ -938,7 +962,6 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup);
  *      @sk: socket which provides route info
  *      @fl6: flow to lookup
  *      @final_dst: final destination address for ipsec lookup
- *      @can_sleep: we are in a sleepable context
  *
  *      This function performs a route lookup on the given flow.
  *
@@ -946,8 +969,7 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup);
  *      error code.
  */
 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
-                                      const struct in6_addr *final_dst,
-                                      bool can_sleep)
+                                      const struct in6_addr *final_dst)
 {
         struct dst_entry *dst = NULL;
         int err;
@@ -957,8 +979,6 @@ struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
                 return ERR_PTR(err);
         if (final_dst)
                 fl6->daddr = *final_dst;
-        if (can_sleep)
-                fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
 
         return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
 }
@@ -969,7 +989,6 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
  *      @sk: socket which provides the dst cache and route info
  *      @fl6: flow to lookup
  *      @final_dst: final destination address for ipsec lookup
- *      @can_sleep: we are in a sleepable context
  *
  *      This function performs a route lookup on the given flow with the
  *      possibility of using the cached route in the socket if it is valid.
@@ -980,8 +999,7 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
  *      error code.
  */
 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
-                                         const struct in6_addr *final_dst,
-                                         bool can_sleep)
+                                         const struct in6_addr *final_dst)
 {
         struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
         int err;
@@ -993,8 +1011,6 @@ struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
                 return ERR_PTR(err);
         if (final_dst)
                 fl6->daddr = *final_dst;
-        if (can_sleep)
-                fl6->flowi6_flags |= FLOWI_FLAG_CAN_SLEEP;
 
         return xfrm_lookup(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0);
 }
@@ -1162,10 +1178,10 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
                 np->cork.hop_limit = hlimit;
                 np->cork.tclass = tclass;
                 if (rt->dst.flags & DST_XFRM_TUNNEL)
-                        mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+                        mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
                               rt->dst.dev->mtu : dst_mtu(&rt->dst);
                 else
-                        mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ?
+                        mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
                               rt->dst.dev->mtu : dst_mtu(rt->dst.path);
                 if (np->frag_size < mtu) {
                         if (np->frag_size)
@@ -1285,7 +1301,7 @@ alloc_new_skb:
                         if (skb == NULL || skb_prev == NULL)
                                 ip6_append_data_mtu(&mtu, &maxfraglen,
                                                     fragheaderlen, skb, rt,
-                                                    np->pmtudisc ==
+                                                    np->pmtudisc >=
                                                     IPV6_PMTUDISC_PROBE);
 
                         skb_prev = skb;