1 files changed, 96 insertions, 62 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 36cf0ab685a0..d5f7716662db 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -56,7 +56,7 @@
 #include <net/checksum.h>
 #include <linux/mroute6.h>
 
-static int ip6_finish_output2(struct sk_buff *skb)
+static int ip6_finish_output2(struct sock *sk, struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);
 	struct net_device *dev = dst->dev;
@@ -70,7 +70,7 @@ static int ip6_finish_output2(struct sk_buff *skb)
 	if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
 		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
-		if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
+		if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) &&
 		    ((mroute6_socket(dev_net(dev), skb) &&
 		     !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
 		     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
@@ -82,7 +82,7 @@ static int ip6_finish_output2(struct sk_buff *skb)
 			 */
 			if (newskb)
 				NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING,
-					newskb, NULL, newskb->dev,
+					sk, newskb, NULL, newskb->dev,
 					dev_loopback_xmit);
 
 			if (ipv6_hdr(skb)->hop_limit == 0) {
@@ -105,7 +105,7 @@ static int ip6_finish_output2(struct sk_buff *skb)
 	}
 
 	rcu_read_lock_bh();
-	nexthop = rt6_nexthop((struct rt6_info *)dst);
+	nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr);
 	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
 	if (unlikely(!neigh))
 		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
@@ -122,14 +122,14 @@ static int ip6_finish_output2(struct sk_buff *skb)
 	return -EINVAL;
 }
 
-static int ip6_finish_output(struct sk_buff *skb)
+static int ip6_finish_output(struct sock *sk, struct sk_buff *skb)
 {
 	if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) ||
 	    dst_allfrag(skb_dst(skb)) ||
 	    (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size))
-		return ip6_fragment(skb, ip6_finish_output2);
+		return ip6_fragment(sk, skb, ip6_finish_output2);
 	else
-		return ip6_finish_output2(skb);
+		return ip6_finish_output2(sk, skb);
 }
 
 int ip6_output(struct sock *sk, struct sk_buff *skb)
@@ -143,7 +143,8 @@ int ip6_output(struct sock *sk, struct sk_buff *skb)
 		return 0;
 	}
 
-	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev,
+	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, sk, skb,
+			    NULL, dev,
 			    ip6_finish_output,
 			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 }
@@ -177,7 +178,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 
 		if (skb_headroom(skb) < head_room) {
 			struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room);
-			if (skb2 == NULL) {
+			if (!skb2) {
 				IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 					      IPSTATS_MIB_OUTDISCARDS);
 				kfree_skb(skb);
@@ -223,8 +224,8 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 	if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
 		IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
 			      IPSTATS_MIB_OUT, skb->len);
-		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL,
-			       dst->dev, dst_output);
+		return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, sk, skb,
+			       NULL, dst->dev, dst_output_sk);
 	}
 
 	skb->dev = dst->dev;
@@ -316,10 +317,10 @@ static int ip6_forward_proxy_check(struct sk_buff *skb)
 	return 0;
 }
 
-static inline int ip6_forward_finish(struct sk_buff *skb)
+static inline int ip6_forward_finish(struct sock *sk, struct sk_buff *skb)
 {
 	skb_sender_cpu_clear(skb);
-	return dst_output(skb);
+	return dst_output_sk(sk, skb);
 }
 
 static unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
@@ -458,7 +459,7 @@ int ip6_forward(struct sk_buff *skb)
 		else
 			target = &hdr->daddr;
 
-		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
+		peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1);
 
 		/* Limit redirects both by destination (here)
 		   and by source (inside ndisc_send_redirect)
@@ -511,7 +512,8 @@ int ip6_forward(struct sk_buff *skb)
 
 	IP6_INC_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS);
 	IP6_ADD_STATS_BH(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len);
-	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, skb, skb->dev, dst->dev,
+	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, NULL, skb,
+		       skb->dev, dst->dev,
 		       ip6_forward_finish);
 
 error:
@@ -538,7 +540,8 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 	skb_copy_secmark(to, from);
 }
 
-int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
+int ip6_fragment(struct sock *sk, struct sk_buff *skb,
+		 int (*output)(struct sock *, struct sk_buff *))
 {
 	struct sk_buff *frag;
 	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
@@ -548,7 +551,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 	struct frag_hdr *fh;
 	unsigned int mtu, hlen, left, len;
 	int hroom, troom;
-	__be32 frag_id = 0;
+	__be32 frag_id;
 	int ptr, offset = 0, err = 0;
 	u8 *prevhdr, nexthdr = 0;
 	struct net *net = dev_net(skb_dst(skb)->dev);
@@ -561,18 +564,17 @@ 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->ignore_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);
+	if (unlikely(!skb->ignore_df && skb->len > mtu))
+		goto fail_toobig;
 
-		skb->dev = skb_dst(skb)->dev;
-		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
-		IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-			      IPSTATS_MIB_FRAGFAILS);
-		kfree_skb(skb);
-		return -EMSGSIZE;
+	if (IP6CB(skb)->frag_max_size) {
+		if (IP6CB(skb)->frag_max_size > mtu)
+			goto fail_toobig;
+
+		/* don't send fragments larger than what we received */
+		mtu = IP6CB(skb)->frag_max_size;
+		if (mtu < IPV6_MIN_MTU)
+			mtu = IPV6_MIN_MTU;
 	}
 
 	if (np && np->frag_size < mtu) {
@@ -581,6 +583,9 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 	}
 	mtu -= hlen + sizeof(struct frag_hdr);
 
+	frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr,
+				    &ipv6_hdr(skb)->saddr);
+
 	if (skb_has_frag_list(skb)) {
 		int first_len = skb_pagelen(skb);
 		struct sk_buff *frag2;
@@ -629,11 +634,10 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 		skb_reset_network_header(skb);
 		memcpy(skb_network_header(skb), tmp_hdr, hlen);
 
-		ipv6_select_ident(fh, rt);
 		fh->nexthdr = nexthdr;
 		fh->reserved = 0;
 		fh->frag_off = htons(IP6_MF);
-		frag_id = fh->identification;
+		fh->identification = frag_id;
 
 		first_len = skb_pagelen(skb);
 		skb->data_len = first_len - skb_headlen(skb);
@@ -658,7 +662,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 				fh->nexthdr = nexthdr;
 				fh->reserved = 0;
 				fh->frag_off = htons(offset);
-				if (frag->next != NULL)
+				if (frag->next)
 					fh->frag_off |= htons(IP6_MF);
 				fh->identification = frag_id;
 				ipv6_hdr(frag)->payload_len =
@@ -667,7 +671,7 @@ int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 				ip6_copy_metadata(frag, skb);
 			}
 
-			err = output(skb);
+			err = output(sk, skb);
 			if (!err)
 				IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
 					      IPSTATS_MIB_FRAGCREATES);
@@ -775,11 +779,7 @@ slow_path:
 		 */
 		fh->nexthdr = nexthdr;
 		fh->reserved = 0;
-		if (!frag_id) {
-			ipv6_select_ident(fh, rt);
-			frag_id = fh->identification;
-		} else
-			fh->identification = frag_id;
+		fh->identification = frag_id;
 
 		/*
 		 *	Copy a block of the IP datagram.
@@ -800,7 +800,7 @@ slow_path:
 		/*
 		 *	Put this fragment into the sending queue.
 		 */
-		err = output(frag);
+		err = output(sk, frag);
 		if (err)
 			goto fail;
 
@@ -812,6 +812,14 @@ slow_path:
 	consume_skb(skb);
 	return err;
 
+fail_toobig:
+	if (skb->sk && dst_allfrag(skb_dst(skb)))
+		sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK);
+
+	skb->dev = skb_dst(skb)->dev;
+	icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+	err = -EMSGSIZE;
+
 fail:
 	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 		      IPSTATS_MIB_FRAGFAILS);
@@ -824,7 +832,7 @@ static inline int ip6_rt_check(const struct rt6key *rt_key,
 			       const struct in6_addr *addr_cache)
 {
 	return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) &&
-		(addr_cache == NULL || !ipv6_addr_equal(fl_addr, addr_cache));
+		(!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache));
 }
 
 static struct dst_entry *ip6_sk_dst_check(struct sock *sk,
@@ -883,22 +891,45 @@ static int ip6_dst_lookup_tail(struct sock *sk,
 #endif
 	int err;
 
-	if (*dst == NULL)
-		*dst = ip6_route_output(net, sk, fl6);
-
-	err = (*dst)->error;
-	if (err)
-		goto out_err_release;
+	/* The correct way to handle this would be to do
+	 * ip6_route_get_saddr, and then ip6_route_output; however,
+	 * the route-specific preferred source forces the
+	 * ip6_route_output call _before_ ip6_route_get_saddr.
+	 *
+	 * In source specific routing (no src=any default route),
+	 * ip6_route_output will fail given src=any saddr, though, so
+	 * that's why we try it again later.
+	 */
+	if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) {
+		struct rt6_info *rt;
+		bool had_dst = *dst != NULL;
 
-	if (ipv6_addr_any(&fl6->saddr)) {
-		struct rt6_info *rt = (struct rt6_info *) *dst;
+		if (!had_dst)
+			*dst = ip6_route_output(net, sk, fl6);
+		rt = (*dst)->error ? NULL : (struct rt6_info *)*dst;
 		err = ip6_route_get_saddr(net, rt, &fl6->daddr,
 					  sk ? inet6_sk(sk)->srcprefs : 0,
 					  &fl6->saddr);
 		if (err)
 			goto out_err_release;
+
+		/* If we had an erroneous initial result, pretend it
+		 * never existed and let the SA-enabled version take
+		 * over.
+		 */
+		if (!had_dst && (*dst)->error) {
+			dst_release(*dst);
+			*dst = NULL;
+		}
 	}
 
+	if (!*dst)
+		*dst = ip6_route_output(net, sk, fl6);
+
+	err = (*dst)->error;
+	if (err)
+		goto out_err_release;
+
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 	/*
 	 * Here if the dst entry we've looked up
@@ -910,7 +941,8 @@ static int ip6_dst_lookup_tail(struct sock *sk,
 	 */
 	rt = (struct rt6_info *) *dst;
 	rcu_read_lock_bh();
-	n = __ipv6_neigh_lookup_noref(rt->dst.dev, rt6_nexthop(rt));
+	n = __ipv6_neigh_lookup_noref(rt->dst.dev,
+				      rt6_nexthop(rt, &fl6->daddr));
 	err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0;
 	rcu_read_unlock_bh();
 
@@ -1034,11 +1066,10 @@ static inline int ip6_ufo_append_data(struct sock *sk,
 			int odd, struct sk_buff *skb),
 			void *from, int length, int hh_len, int fragheaderlen,
 			int transhdrlen, int mtu, unsigned int flags,
-			struct rt6_info *rt)
+			const struct flowi6 *fl6)
 
 {
 	struct sk_buff *skb;
-	struct frag_hdr fhdr;
 	int err;
 
 	/* There is support for UDP large send offload by network
@@ -1046,11 +1077,11 @@ static inline int ip6_ufo_append_data(struct sock *sk,
 	 * udp datagram
 	 */
 	skb = skb_peek_tail(queue);
-	if (skb == NULL) {
+	if (!skb) {
 		skb = sock_alloc_send_skb(sk,
 			hh_len + fragheaderlen + transhdrlen + 20,
 			(flags & MSG_DONTWAIT), &err);
-		if (skb == NULL)
+		if (!skb)
 			return err;
 
 		/* reserve space for Hardware header */
@@ -1080,8 +1111,9 @@ static inline int ip6_ufo_append_data(struct sock *sk,
 	skb_shinfo(skb)->gso_size = (mtu - fragheaderlen -
 				     sizeof(struct frag_hdr)) & ~7;
 	skb_shinfo(skb)->gso_type = SKB_GSO_UDP;
-	ipv6_select_ident(&fhdr, rt);
-	skb_shinfo(skb)->ip6_frag_id = fhdr.identification;
+	skb_shinfo(skb)->ip6_frag_id = ipv6_select_ident(sock_net(sk),
+							 &fl6->daddr,
+							 &fl6->saddr);
 
 append:
 	return skb_append_datato_frags(sk, skb, getfrag, from,
@@ -1108,7 +1140,7 @@ static void ip6_append_data_mtu(unsigned int *mtu,
 				unsigned int orig_mtu)
 {
 	if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
-		if (skb == NULL) {
+		if (!skb) {
 			/* first fragment, reserve header_len */
 			*mtu = orig_mtu - rt->dst.header_len;
 
@@ -1140,7 +1172,7 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 			return -EINVAL;
 
 		v6_cork->opt = kzalloc(opt->tot_len, sk->sk_allocation);
-		if (unlikely(v6_cork->opt == NULL))
+		if (unlikely(!v6_cork->opt))
 			return -ENOBUFS;
 
 		v6_cork->opt->tot_len = opt->tot_len;
@@ -1274,8 +1306,10 @@ emsgsize:
 
 	/* If this is the first and only packet and device
 	 * supports checksum offloading, let's use it.
+	 * Use transhdrlen, same as IPv4, because partial
+	 * sums only work when transhdrlen is set.
 	 */
-	if (!skb && sk->sk_protocol == IPPROTO_UDP &&
+	if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
 	    length + fragheaderlen < mtu &&
 	    rt->dst.dev->features & NETIF_F_V6_CSUM &&
 	    !exthdrlen)
@@ -1304,7 +1338,7 @@ emsgsize:
 	    (sk->sk_type == SOCK_DGRAM)) {
 		err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
 					  hh_len, fragheaderlen,
-					  transhdrlen, mtu, flags, rt);
+					  transhdrlen, mtu, flags, fl6);
 		if (err)
 			goto error;
 		return 0;
@@ -1332,7 +1366,7 @@ alloc_new_skb:
 			else
 				fraggap = 0;
 			/* update mtu and maxfraglen if necessary */
-			if (skb == NULL || skb_prev == NULL)
+			if (!skb || !skb_prev)
 				ip6_append_data_mtu(&mtu, &maxfraglen,
 						    fragheaderlen, skb, rt,
 						    orig_mtu);
@@ -1384,10 +1418,10 @@ alloc_new_skb:
 					skb = sock_wmalloc(sk,
 							   alloclen + hh_len, 1,
 							   sk->sk_allocation);
-				if (unlikely(skb == NULL))
+				if (unlikely(!skb))
 					err = -ENOBUFS;
 			}
-			if (skb == NULL)
+			if (!skb)
 				goto error;
 			/*
 			 *	Fill in the control structures
@@ -1579,7 +1613,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 	unsigned char proto = fl6->flowi6_proto;
 
 	skb = __skb_dequeue(queue);
-	if (skb == NULL)
+	if (!skb)
 		goto out;
 	tail_skb = &(skb_shinfo(skb)->frag_list);