1 files changed, 119 insertions, 121 deletions

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 07beeb06f75..cc85a9ba501 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -26,6 +26,9 @@
  *	YOSHIFUJI,H. @USAGI	Always remove fragment header to
  *				calculate ICV correctly.
  */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/string.h>
@@ -42,6 +45,7 @@
 #include <linux/jhash.h>
 #include <linux/skbuff.h>
 #include <linux/slab.h>
+#include <linux/export.h>
 
 #include <net/sock.h>
 #include <net/snmp.h>
@@ -54,6 +58,7 @@
 #include <net/ndisc.h>
 #include <net/addrconf.h>
 #include <net/inet_frag.h>
+#include <net/inet_ecn.h>
 
 struct ip6frag_skb_cb
 {
@@ -63,36 +68,12 @@ struct ip6frag_skb_cb
 
 #define FRAG6_CB(skb)	((struct ip6frag_skb_cb*)((skb)->cb))
 
-
-/*
- *	Equivalent of ipv4 struct ipq
- */
-
-struct frag_queue
-{
-	struct inet_frag_queue	q;
-
-	__be32			id;		/* fragment id		*/
-	u32			user;
-	struct in6_addr		saddr;
-	struct in6_addr		daddr;
-
-	int			iif;
-	unsigned int		csum;
-	__u16			nhoffset;
-};
-
-static struct inet_frags ip6_frags;
-
-int ip6_frag_nqueues(struct net *net)
+static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 {
-	return net->ipv6.frags.nqueues;
+	return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
 }
 
-int ip6_frag_mem(struct net *net)
-{
-	return atomic_read(&net->ipv6.frags.mem);
-}
+static struct inet_frags ip6_frags;
 
 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 			  struct net_device *dev);
@@ -101,47 +82,36 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
  * callers should be careful not to use the hash value outside the ipfrag_lock
  * as doing so could race with ipfrag_hash_rnd being recalculated.
  */
-unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
-			     const struct in6_addr *daddr, u32 rnd)
+static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
+				    const struct in6_addr *daddr)
 {
 	u32 c;
 
-	c = jhash_3words((__force u32)saddr->s6_addr32[0],
-			 (__force u32)saddr->s6_addr32[1],
-			 (__force u32)saddr->s6_addr32[2],
-			 rnd);
-
-	c = jhash_3words((__force u32)saddr->s6_addr32[3],
-			 (__force u32)daddr->s6_addr32[0],
-			 (__force u32)daddr->s6_addr32[1],
-			 c);
-
-	c =  jhash_3words((__force u32)daddr->s6_addr32[2],
-			  (__force u32)daddr->s6_addr32[3],
-			  (__force u32)id,
-			  c);
+	net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd));
+	c = jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
+			 (__force u32)id, ip6_frags.rnd);
 
 	return c & (INETFRAGS_HASHSZ - 1);
 }
-EXPORT_SYMBOL_GPL(inet6_hash_frag);
 
 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
 {
 	struct frag_queue *fq;
 
 	fq = container_of(q, struct frag_queue, q);
-	return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
+	return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr);
 }
 
-int ip6_frag_match(struct inet_frag_queue *q, void *a)
+bool ip6_frag_match(struct inet_frag_queue *q, void *a)
 {
 	struct frag_queue *fq;
 	struct ip6_create_arg *arg = a;
 
 	fq = container_of(q, struct frag_queue, q);
-	return (fq->id == arg->id && fq->user == arg->user &&
-			ipv6_addr_equal(&fq->saddr, arg->src) &&
-			ipv6_addr_equal(&fq->daddr, arg->dst));
+	return	fq->id == arg->id &&
+		fq->user == arg->user &&
+		ipv6_addr_equal(&fq->saddr, arg->src) &&
+		ipv6_addr_equal(&fq->daddr, arg->dst);
 }
 EXPORT_SYMBOL(ip6_frag_match);
 
@@ -152,51 +122,24 @@ void ip6_frag_init(struct inet_frag_queue *q, void *a)
 
 	fq->id = arg->id;
 	fq->user = arg->user;
-	ipv6_addr_copy(&fq->saddr, arg->src);
-	ipv6_addr_copy(&fq->daddr, arg->dst);
+	fq->saddr = *arg->src;
+	fq->daddr = *arg->dst;
+	fq->ecn = arg->ecn;
 }
 EXPORT_SYMBOL(ip6_frag_init);
 
-/* Destruction primitives. */
-
-static __inline__ void fq_put(struct frag_queue *fq)
-{
-	inet_frag_put(&fq->q, &ip6_frags);
-}
-
-/* Kill fq entry. It is not destroyed immediately,
- * because caller (and someone more) holds reference count.
- */
-static __inline__ void fq_kill(struct frag_queue *fq)
-{
-	inet_frag_kill(&fq->q, &ip6_frags);
-}
-
-static void ip6_evictor(struct net *net, struct inet6_dev *idev)
-{
-	int evicted;
-
-	evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
-	if (evicted)
-		IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
-}
-
-static void ip6_frag_expire(unsigned long data)
+void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
+			   struct inet_frags *frags)
 {
-	struct frag_queue *fq;
 	struct net_device *dev = NULL;
-	struct net *net;
-
-	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
 
 	spin_lock(&fq->q.lock);
 
 	if (fq->q.last_in & INET_FRAG_COMPLETE)
 		goto out;
 
-	fq_kill(fq);
+	inet_frag_kill(&fq->q, frags);
 
-	net = container_of(fq->q.net, struct net, ipv6.frags);
 	rcu_read_lock();
 	dev = dev_get_by_index_rcu(net, fq->iif);
 	if (!dev)
@@ -220,11 +163,24 @@ out_rcu_unlock:
 	rcu_read_unlock();
 out:
 	spin_unlock(&fq->q.lock);
-	fq_put(fq);
+	inet_frag_put(&fq->q, frags);
+}
+EXPORT_SYMBOL(ip6_expire_frag_queue);
+
+static void ip6_frag_expire(unsigned long data)
+{
+	struct frag_queue *fq;
+	struct net *net;
+
+	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	net = container_of(fq->q.net, struct net, ipv6.frags);
+
+	ip6_expire_frag_queue(net, fq, &ip6_frags);
 }
 
 static __inline__ struct frag_queue *
-fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst)
+fq_find(struct net *net, __be32 id, const struct in6_addr *src,
+	const struct in6_addr *dst, u8 ecn)
 {
 	struct inet_frag_queue *q;
 	struct ip6_create_arg arg;
@@ -234,14 +190,16 @@ fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst)
 	arg.user = IP6_DEFRAG_LOCAL_DELIVER;
 	arg.src = src;
 	arg.dst = dst;
+	arg.ecn = ecn;
 
 	read_lock(&ip6_frags.lock);
-	hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
+	hash = inet6_hash_frag(id, src, dst);
 
 	q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
-	if (q == NULL)
+	if (IS_ERR_OR_NULL(q)) {
+		inet_frag_maybe_warn_overflow(q, pr_fmt());
 		return NULL;
-
+	}
 	return container_of(q, struct frag_queue, q);
 }
 
@@ -252,6 +210,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 	struct net_device *dev;
 	int offset, end;
 	struct net *net = dev_net(skb_dst(skb)->dev);
+	u8 ecn;
 
 	if (fq->q.last_in & INET_FRAG_COMPLETE)
 		goto err;
@@ -269,6 +228,8 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 		return -1;
 	}
 
+	ecn = ip6_frag_ecn(ipv6_hdr(skb));
+
 	if (skb->ip_summed == CHECKSUM_COMPLETE) {
 		const unsigned char *nh = skb_network_header(skb);
 		skb->csum = csum_sub(skb->csum,
@@ -335,12 +296,11 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 	}
 
 found:
-	/* RFC5722, Section 4:
-	 *                                  When reassembling an IPv6 datagram, if
+	/* RFC5722, Section 4, amended by Errata ID : 3089
+	 *                          When reassembling an IPv6 datagram, if
 	 *   one or more its constituent fragments is determined to be an
 	 *   overlapping fragment, the entire datagram (and any constituent
-	 *   fragments, including those not yet received) MUST be silently
-	 *   discarded.
+	 *   fragments) MUST be silently discarded.
 	 */
 
 	/* Check for overlap with preceding fragment. */
@@ -370,7 +330,8 @@ found:
 	}
 	fq->q.stamp = skb->tstamp;
 	fq->q.meat += skb->len;
-	atomic_add(skb->truesize, &fq->q.net->mem);
+	fq->ecn |= ecn;
+	add_frag_mem_limit(&fq->q, skb->truesize);
 
 	/* The first fragment.
 	 * nhoffset is obtained from the first fragment, of course.
@@ -381,16 +342,22 @@ found:
 	}
 
 	if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
-	    fq->q.meat == fq->q.len)
-		return ip6_frag_reasm(fq, prev, dev);
+	    fq->q.meat == fq->q.len) {
+		int res;
+		unsigned long orefdst = skb->_skb_refdst;
+
+		skb->_skb_refdst = 0UL;
+		res = ip6_frag_reasm(fq, prev, dev);
+		skb->_skb_refdst = orefdst;
+		return res;
+	}
 
-	write_lock(&ip6_frags.lock);
-	list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
-	write_unlock(&ip6_frags.lock);
+	skb_dst_drop(skb);
+	inet_frag_lru_move(&fq->q);
 	return -1;
 
 discard_fq:
-	fq_kill(fq);
+	inet_frag_kill(&fq->q, &ip6_frags);
 err:
 	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 		      IPSTATS_MIB_REASMFAILS);
@@ -414,8 +381,14 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	struct sk_buff *fp, *head = fq->q.fragments;
 	int    payload_len;
 	unsigned int nhoff;
+	int sum_truesize;
+	u8 ecn;
+
+	inet_frag_kill(&fq->q, &ip6_frags);
 
-	fq_kill(fq);
+	ecn = ip_frag_ecn_table[fq->ecn];
+	if (unlikely(ecn == 0xff))
+		goto out_fail;
 
 	/* Make the one we just received the head. */
 	if (prev) {
@@ -433,7 +406,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 		skb_morph(head, fq->q.fragments);
 		head->next = fq->q.fragments->next;
 
-		kfree_skb(fq->q.fragments);
+		consume_skb(fq->q.fragments);
 		fq->q.fragments = head;
 	}
 
@@ -448,7 +421,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 		goto out_oversize;
 
 	/* Head of list must not be cloned. */
-	if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
+	if (skb_unclone(head, GFP_ATOMIC))
 		goto out_oom;
 
 	/* If the first fragment is fragmented itself, we split
@@ -464,14 +437,14 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 		head->next = clone;
 		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 		skb_frag_list_init(head);
-		for (i=0; i<skb_shinfo(head)->nr_frags; i++)
-			plen += skb_shinfo(head)->frags[i].size;
+		for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+			plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 		clone->len = clone->data_len = head->data_len - plen;
 		head->data_len -= clone->len;
 		head->len -= clone->len;
 		clone->csum = 0;
 		clone->ip_summed = head->ip_summed;
-		atomic_add(clone->truesize, &fq->q.net->mem);
+		add_frag_mem_limit(&fq->q, clone->truesize);
 	}
 
 	/* We have to remove fragment header from datagram and to relocate
@@ -483,26 +456,41 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	head->mac_header += sizeof(struct frag_hdr);
 	head->network_header += sizeof(struct frag_hdr);
 
-	skb_shinfo(head)->frag_list = head->next;
 	skb_reset_transport_header(head);
 	skb_push(head, head->data - skb_network_header(head));
 
-	for (fp=head->next; fp; fp = fp->next) {
-		head->data_len += fp->len;
-		head->len += fp->len;
+	sum_truesize = head->truesize;
+	for (fp = head->next; fp;) {
+		bool headstolen;
+		int delta;
+		struct sk_buff *next = fp->next;
+
+		sum_truesize += fp->truesize;
 		if (head->ip_summed != fp->ip_summed)
 			head->ip_summed = CHECKSUM_NONE;
 		else if (head->ip_summed == CHECKSUM_COMPLETE)
 			head->csum = csum_add(head->csum, fp->csum);
-		head->truesize += fp->truesize;
+
+		if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
+			kfree_skb_partial(fp, headstolen);
+		} else {
+			if (!skb_shinfo(head)->frag_list)
+				skb_shinfo(head)->frag_list = fp;
+			head->data_len += fp->len;
+			head->len += fp->len;
+			head->truesize += fp->truesize;
+		}
+		fp = next;
 	}
-	atomic_sub(head->truesize, &fq->q.net->mem);
+	sub_frag_mem_limit(&fq->q, sum_truesize);
 
 	head->next = NULL;
 	head->dev = dev;
 	head->tstamp = fq->q.stamp;
 	ipv6_hdr(head)->payload_len = htons(payload_len);
+	ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
 	IP6CB(head)->nhoff = nhoff;
+	IP6CB(head)->flags |= IP6SKB_FRAGMENTED;
 
 	/* Yes, and fold redundant checksum back. 8) */
 	if (head->ip_summed == CHECKSUM_COMPLETE)
@@ -518,12 +506,10 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	return 1;
 
 out_oversize:
-	if (net_ratelimit())
-		printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
+	net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len);
 	goto out_fail;
 out_oom:
-	if (net_ratelimit())
-		printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
+	net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n");
 out_fail:
 	rcu_read_lock();
 	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
@@ -535,8 +521,12 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 {
 	struct frag_hdr *fhdr;
 	struct frag_queue *fq;
-	struct ipv6hdr *hdr = ipv6_hdr(skb);
+	const struct ipv6hdr *hdr = ipv6_hdr(skb);
 	struct net *net = dev_net(skb_dst(skb)->dev);
+	int evicted;
+
+	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
+		goto fail_hdr;
 
 	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
 
@@ -558,13 +548,17 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 				 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
 
 		IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
+		IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
 		return 1;
 	}
 
-	if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
-		ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
+	evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags, false);
+	if (evicted)
+		IP6_ADD_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
+				 IPSTATS_MIB_REASMFAILS, evicted);
 
-	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
+	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
+		     ip6_frag_ecn(hdr));
 	if (fq != NULL) {
 		int ret;
 
@@ -573,7 +567,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 
 		spin_unlock(&fq->q.lock);
-		fq_put(fq);
+		inet_frag_put(&fq->q, &ip6_frags);
 		return ret;
 	}
 
@@ -644,9 +638,13 @@ static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 		table[0].data = &net->ipv6.frags.high_thresh;
 		table[1].data = &net->ipv6.frags.low_thresh;
 		table[2].data = &net->ipv6.frags.timeout;
+
+		/* Don't export sysctls to unprivileged users */
+		if (net->user_ns != &init_user_ns)
+			table[0].procname = NULL;
 	}
 
-	hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
+	hdr = register_net_sysctl(net, "net/ipv6", table);
 	if (hdr == NULL)
 		goto err_reg;
 
@@ -674,7 +672,7 @@ static struct ctl_table_header *ip6_ctl_header;
 
 static int ip6_frags_sysctl_register(void)
 {
-	ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
+	ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6",
 			ip6_frags_ctl_table);
 	return ip6_ctl_header == NULL ? -ENOMEM : 0;
 }