1 files changed, 103 insertions, 45 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 9a311cc7967..45702b8cd14 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -132,7 +132,7 @@ static int ip6_finish_output(struct sk_buff *skb)
 		return ip6_finish_output2(skb);
 }
 
-int ip6_output(struct sk_buff *skb)
+int ip6_output(struct sock *sk, struct sk_buff *skb)
 {
 	struct net_device *dev = skb_dst(skb)->dev;
 	struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
@@ -219,7 +219,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 	skb->mark = sk->sk_mark;
 
 	mtu = dst_mtu(dst);
-	if ((skb->len <= mtu) || skb->local_df || skb_is_gso(skb)) {
+	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,
@@ -321,6 +321,45 @@ 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;
+}
+
+static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+{
+	if (skb->len <= mtu)
+		return false;
+
+	/* ipv6 conntrack defrag sets max_frag_size + ignore_df */
+	if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)
+		return true;
+
+	if (skb->ignore_df)
+		return false;
+
+	if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+		return false;
+
+	return true;
+}
+
 int ip6_forward(struct sk_buff *skb)
 {
 	struct dst_entry *dst = skb_dst(skb);
@@ -332,6 +371,9 @@ int ip6_forward(struct sk_buff *skb)
 	if (net->ipv6.devconf_all->forwarding == 0)
 		goto error;
 
+	if (skb->pkt_type != PACKET_HOST)
+		goto drop;
+
 	if (skb_warn_if_lro(skb))
 		goto drop;
 
@@ -341,9 +383,6 @@ int ip6_forward(struct sk_buff *skb)
 		goto drop;
 	}
 
-	if (skb->pkt_type != PACKET_HOST)
-		goto drop;
-
 	skb_forward_csum(skb);
 
 	/*
@@ -441,12 +480,11 @@ 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;
 
-	if ((!skb->local_df && skb->len > mtu && !skb_is_gso(skb)) ||
-	    (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu)) {
+	if (ip6_pkt_too_big(skb, mtu)) {
 		/* Again, force OUTPUT device used as source address */
 		skb->dev = dst->dev;
 		icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
@@ -496,12 +534,23 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 	to->tc_index = from->tc_index;
 #endif
 	nf_copy(to, from);
-#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
-	to->nf_trace = from->nf_trace;
-#endif
 	skb_copy_secmark(to, from);
 }
 
+static void ipv6_select_ident(struct frag_hdr *fhdr, struct rt6_info *rt)
+{
+	static u32 ip6_idents_hashrnd __read_mostly;
+	u32 hash, id;
+
+	net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
+
+	hash = __ipv6_addr_jhash(&rt->rt6i_dst.addr, ip6_idents_hashrnd);
+	hash = __ipv6_addr_jhash(&rt->rt6i_src.addr, hash);
+
+	id = ip_idents_reserve(hash, 1);
+	fhdr->identification = htonl(id);
+}
+
 int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
 {
 	struct sk_buff *frag;
@@ -524,7 +573,7 @@ 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->ignore_df && skb->len > mtu) ||
 		     (IP6CB(skb)->frag_max_size &&
 		      IP6CB(skb)->frag_max_size > mtu)) {
 		if (skb->sk && dst_allfrag(skb_dst(skb)))
@@ -941,7 +990,6 @@ 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.
  *
@@ -949,8 +997,7 @@ 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;
@@ -960,8 +1007,6 @@ 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);
 }
@@ -972,7 +1017,6 @@ 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.
@@ -983,8 +1027,7 @@ 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;
@@ -996,8 +1039,6 @@ 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);
 }
@@ -1078,21 +1119,19 @@ static void ip6_append_data_mtu(unsigned int *mtu,
 				unsigned int fragheaderlen,
 				struct sk_buff *skb,
 				struct rt6_info *rt,
-				bool pmtuprobe)
+				unsigned int orig_mtu)
 {
 	if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
 		if (skb == NULL) {
 			/* first fragment, reserve header_len */
-			*mtu = *mtu - rt->dst.header_len;
+			*mtu = orig_mtu - rt->dst.header_len;
 
 		} else {
 			/*
 			 * this fragment is not first, the headers
 			 * space is regarded as data space.
 			 */
-			*mtu = min(*mtu, pmtuprobe ?
-				   rt->dst.dev->mtu :
-				   dst_mtu(rt->dst.path));
+			*mtu = orig_mtu;
 		}
 		*maxfraglen = ((*mtu - fragheaderlen) & ~7)
 			      + fragheaderlen - sizeof(struct frag_hdr);
@@ -1109,7 +1148,7 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct inet_cork *cork;
 	struct sk_buff *skb, *skb_prev = NULL;
-	unsigned int maxfraglen, fragheaderlen, mtu;
+	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
 	int exthdrlen;
 	int dst_exthdrlen;
 	int hh_len;
@@ -1165,10 +1204,10 @@ 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)
@@ -1191,16 +1230,43 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 		dst_exthdrlen = 0;
 		mtu = cork->fragsize;
 	}
+	orig_mtu = mtu;
 
 	hh_len = LL_RESERVED_SPACE(rt->dst.dev);
 
 	fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
 			(opt ? opt->opt_nflen : 0);
-	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr);
+	maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
+		     sizeof(struct frag_hdr);
 
 	if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) {
-		if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) {
-			ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen);
+		unsigned int maxnonfragsize, headersize;
+
+		headersize = sizeof(struct ipv6hdr) +
+			     (opt ? opt->opt_flen + opt->opt_nflen : 0) +
+			     (dst_allfrag(&rt->dst) ?
+			      sizeof(struct frag_hdr) : 0) +
+			     rt->rt6i_nfheader_len;
+
+		if (ip6_sk_ignore_df(sk))
+			maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
+		else
+			maxnonfragsize = mtu;
+
+		/* dontfrag active */
+		if ((cork->length + length > mtu - headersize) && dontfrag &&
+		    (sk->sk_protocol == IPPROTO_UDP ||
+		     sk->sk_protocol == IPPROTO_RAW)) {
+			ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
+						   sizeof(struct ipv6hdr));
+			goto emsgsize;
+		}
+
+		if (cork->length + length > maxnonfragsize - headersize) {
+emsgsize:
+			ipv6_local_error(sk, EMSGSIZE, fl6,
+					 mtu - headersize +
+					 sizeof(struct ipv6hdr));
 			return -EMSGSIZE;
 		}
 	}
@@ -1225,12 +1291,6 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
 	 * --yoshfuji
 	 */
 
-	if ((length > mtu) && dontfrag && (sk->sk_protocol == IPPROTO_UDP ||
-					   sk->sk_protocol == IPPROTO_RAW)) {
-		ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen);
-		return -EMSGSIZE;
-	}
-
 	skb = skb_peek_tail(&sk->sk_write_queue);
 	cork->length += length;
 	if (((length > mtu) ||
@@ -1270,8 +1330,7 @@ alloc_new_skb:
 			if (skb == NULL || skb_prev == NULL)
 				ip6_append_data_mtu(&mtu, &maxfraglen,
 						    fragheaderlen, skb, rt,
-						    np->pmtudisc ==
-						    IPV6_PMTUDISC_PROBE);
+						    orig_mtu);
 
 			skb_prev = skb;
 
@@ -1499,8 +1558,7 @@ int ip6_push_pending_frames(struct sock *sk)
 	}
 
 	/* Allow local fragmentation. */
-	if (np->pmtudisc < IPV6_PMTUDISC_DO)
-		skb->local_df = 1;
+	skb->ignore_df = ip6_sk_ignore_df(sk);
 
 	*final_dst = fl6->daddr;
 	__skb_pull(skb, skb_network_header_len(skb));
@@ -1527,8 +1585,8 @@ int ip6_push_pending_frames(struct sock *sk)
 	if (proto == IPPROTO_ICMPV6) {
 		struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
 
-		ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type);
-		ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
+		ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type);
+		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
 	}
 
 	err = ip6_local_out(skb);