1 files changed, 92 insertions, 271 deletions

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 74ffbcb306a6..3f488555999e 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -57,18 +57,11 @@
 #include <net/rawv6.h>
 #include <net/ndisc.h>
 #include <net/addrconf.h>
-#include <net/inet_frag.h>
+#include <net/ipv6_frag.h>
 #include <net/inet_ecn.h>
 
 static const char ip6_frag_cache_name[] = "ip6-frags";
 
-struct ip6frag_skb_cb {
-	struct inet6_skb_parm	h;
-	int			offset;
-};
-
-#define FRAG6_CB(skb)	((struct ip6frag_skb_cb *)((skb)->cb))
-
 static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 {
 	return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
@@ -76,63 +69,8 @@ static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 
 static struct inet_frags ip6_frags;
 
-static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
-			  struct net_device *dev);
-
-void ip6_frag_init(struct inet_frag_queue *q, const void *a)
-{
-	struct frag_queue *fq = container_of(q, struct frag_queue, q);
-	const struct frag_v6_compare_key *key = a;
-
-	q->key.v6 = *key;
-	fq->ecn = 0;
-}
-EXPORT_SYMBOL(ip6_frag_init);
-
-void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq)
-{
-	struct net_device *dev = NULL;
-	struct sk_buff *head;
-
-	rcu_read_lock();
-	spin_lock(&fq->q.lock);
-
-	if (fq->q.flags & INET_FRAG_COMPLETE)
-		goto out;
-
-	inet_frag_kill(&fq->q);
-
-	dev = dev_get_by_index_rcu(net, fq->iif);
-	if (!dev)
-		goto out;
-
-	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
-	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
-
-	/* Don't send error if the first segment did not arrive. */
-	head = fq->q.fragments;
-	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !head)
-		goto out;
-
-	/* But use as source device on which LAST ARRIVED
-	 * segment was received. And do not use fq->dev
-	 * pointer directly, device might already disappeared.
-	 */
-	head->dev = dev;
-	skb_get(head);
-	spin_unlock(&fq->q.lock);
-
-	icmpv6_send(head, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
-	kfree_skb(head);
-	goto out_rcu_unlock;
-
-out:
-	spin_unlock(&fq->q.lock);
-out_rcu_unlock:
-	rcu_read_unlock();
-	inet_frag_put(&fq->q);
-}
-EXPORT_SYMBOL(ip6_expire_frag_queue);
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
+			  struct sk_buff *prev_tail, struct net_device *dev);
 
 static void ip6_frag_expire(unsigned long data)
 {
@@ -142,7 +80,7 @@ static void ip6_frag_expire(unsigned long data)
 	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);
+	ip6frag_expire_frag_queue(net, fq);
 }
 
 static struct frag_queue *
@@ -169,27 +107,29 @@ fq_find(struct net *net, __be32 id, const struct ipv6hdr *hdr, int iif)
 }
 
 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
-			   struct frag_hdr *fhdr, int nhoff)
+			  struct frag_hdr *fhdr, int nhoff,
+			  u32 *prob_offset)
 {
-	struct sk_buff *prev, *next;
-	struct net_device *dev;
-	int offset, end;
 	struct net *net = dev_net(skb_dst(skb)->dev);
+	int offset, end, fragsize;
+	struct sk_buff *prev_tail;
+	struct net_device *dev;
+	int err = -ENOENT;
 	u8 ecn;
 
 	if (fq->q.flags & INET_FRAG_COMPLETE)
 		goto err;
 
+	err = -EINVAL;
 	offset = ntohs(fhdr->frag_off) & ~0x7;
 	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 
 	if ((unsigned int)end > IPV6_MAXPLEN) {
-		__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-				IPSTATS_MIB_INHDRERRORS);
-		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
-				  ((u8 *)&fhdr->frag_off -
-				   skb_network_header(skb)));
+		*prob_offset = (u8 *)&fhdr->frag_off - skb_network_header(skb);
+		/* note that if prob_offset is set, the skb is freed elsewhere,
+		 * we do not free it here.
+		 */
 		return -1;
 	}
 
@@ -209,7 +149,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 		 */
 		if (end < fq->q.len ||
 		    ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
-			goto err;
+			goto discard_fq;
 		fq->q.flags |= INET_FRAG_LAST_IN;
 		fq->q.len = end;
 	} else {
@@ -220,84 +160,51 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 			/* RFC2460 says always send parameter problem in
 			 * this case. -DaveM
 			 */
-			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
-					IPSTATS_MIB_INHDRERRORS);
-			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
-					  offsetof(struct ipv6hdr, payload_len));
+			*prob_offset = offsetof(struct ipv6hdr, payload_len);
 			return -1;
 		}
 		if (end > fq->q.len) {
 			/* Some bits beyond end -> corruption. */
 			if (fq->q.flags & INET_FRAG_LAST_IN)
-				goto err;
+				goto discard_fq;
 			fq->q.len = end;
 		}
 	}
 
 	if (end == offset)
-		goto err;
+		goto discard_fq;
 
+	err = -ENOMEM;
 	/* Point into the IP datagram 'data' part. */
 	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
-		goto err;
-
-	if (pskb_trim_rcsum(skb, end - offset))
-		goto err;
-
-	/* Find out which fragments are in front and at the back of us
-	 * in the chain of fragments so far.  We must know where to put
-	 * this fragment, right?
-	 */
-	prev = fq->q.fragments_tail;
-	if (!prev || FRAG6_CB(prev)->offset < offset) {
-		next = NULL;
-		goto found;
-	}
-	prev = NULL;
-	for (next = fq->q.fragments; next != NULL; next = next->next) {
-		if (FRAG6_CB(next)->offset >= offset)
-			break;	/* bingo! */
-		prev = next;
-	}
-
-found:
-	/* 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) MUST be silently discarded.
-	 */
-
-	/* Check for overlap with preceding fragment. */
-	if (prev &&
-	    (FRAG6_CB(prev)->offset + prev->len) > offset)
 		goto discard_fq;
 
-	/* Look for overlap with succeeding segment. */
-	if (next && FRAG6_CB(next)->offset < end)
+	err = pskb_trim_rcsum(skb, end - offset);
+	if (err)
 		goto discard_fq;
 
-	FRAG6_CB(skb)->offset = offset;
+	/* Note : skb->rbnode and skb->dev share the same location. */
+	dev = skb->dev;
+	/* Makes sure compiler wont do silly aliasing games */
+	barrier();
 
-	/* Insert this fragment in the chain of fragments. */
-	skb->next = next;
-	if (!next)
-		fq->q.fragments_tail = skb;
-	if (prev)
-		prev->next = skb;
-	else
-		fq->q.fragments = skb;
+	prev_tail = fq->q.fragments_tail;
+	err = inet_frag_queue_insert(&fq->q, skb, offset, end);
+	if (err)
+		goto insert_error;
 
-	dev = skb->dev;
-	if (dev) {
+	if (dev)
 		fq->iif = dev->ifindex;
-		skb->dev = NULL;
-	}
+
 	fq->q.stamp = skb->tstamp;
 	fq->q.meat += skb->len;
 	fq->ecn |= ecn;
 	add_frag_mem_limit(fq->q.net, skb->truesize);
 
+	fragsize = -skb_network_offset(skb) + skb->len;
+	if (fragsize > fq->q.max_size)
+		fq->q.max_size = fragsize;
+
 	/* The first fragment.
 	 * nhoffset is obtained from the first fragment, of course.
 	 */
@@ -308,44 +215,48 @@ found:
 
 	if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 	    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);
+		err = ip6_frag_reasm(fq, skb, prev_tail, dev);
 		skb->_skb_refdst = orefdst;
-		return res;
+		return err;
 	}
 
 	skb_dst_drop(skb);
-	return -1;
+	return -EINPROGRESS;
 
+insert_error:
+	if (err == IPFRAG_DUP) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+	err = -EINVAL;
+	__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+			IPSTATS_MIB_REASM_OVERLAPS);
 discard_fq:
 	inet_frag_kill(&fq->q);
-err:
 	__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 			IPSTATS_MIB_REASMFAILS);
+err:
 	kfree_skb(skb);
-	return -1;
+	return err;
 }
 
 /*
  *	Check if this packet is complete.
- *	Returns NULL on failure by any reason, and pointer
- *	to current nexthdr field in reassembled frame.
  *
  *	It is called with locked fq, and caller must check that
  *	queue is eligible for reassembly i.e. it is not COMPLETE,
  *	the last and the first frames arrived and all the bits are here.
  */
-static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
-			  struct net_device *dev)
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *skb,
+			  struct sk_buff *prev_tail, struct net_device *dev)
 {
 	struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
-	struct sk_buff *fp, *head = fq->q.fragments;
-	int    payload_len;
 	unsigned int nhoff;
-	int sum_truesize;
+	void *reasm_data;
+	int payload_len;
 	u8 ecn;
 
 	inet_frag_kill(&fq->q);
@@ -354,113 +265,40 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	if (unlikely(ecn == 0xff))
 		goto out_fail;
 
-	/* Make the one we just received the head. */
-	if (prev) {
-		head = prev->next;
-		fp = skb_clone(head, GFP_ATOMIC);
-
-		if (!fp)
-			goto out_oom;
-
-		fp->next = head->next;
-		if (!fp->next)
-			fq->q.fragments_tail = fp;
-		prev->next = fp;
-
-		skb_morph(head, fq->q.fragments);
-		head->next = fq->q.fragments->next;
-
-		consume_skb(fq->q.fragments);
-		fq->q.fragments = head;
-	}
-
-	WARN_ON(head == NULL);
-	WARN_ON(FRAG6_CB(head)->offset != 0);
+	reasm_data = inet_frag_reasm_prepare(&fq->q, skb, prev_tail);
+	if (!reasm_data)
+		goto out_oom;
 
-	/* Unfragmented part is taken from the first segment. */
-	payload_len = ((head->data - skb_network_header(head)) -
+	payload_len = ((skb->data - skb_network_header(skb)) -
 		       sizeof(struct ipv6hdr) + fq->q.len -
 		       sizeof(struct frag_hdr));
 	if (payload_len > IPV6_MAXPLEN)
 		goto out_oversize;
 
-	/* Head of list must not be cloned. */
-	if (skb_unclone(head, GFP_ATOMIC))
-		goto out_oom;
-
-	/* If the first fragment is fragmented itself, we split
-	 * it to two chunks: the first with data and paged part
-	 * and the second, holding only fragments. */
-	if (skb_has_frag_list(head)) {
-		struct sk_buff *clone;
-		int i, plen = 0;
-
-		clone = alloc_skb(0, GFP_ATOMIC);
-		if (!clone)
-			goto out_oom;
-		clone->next = head->next;
-		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_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;
-		add_frag_mem_limit(fq->q.net, clone->truesize);
-	}
-
 	/* We have to remove fragment header from datagram and to relocate
 	 * header in order to calculate ICV correctly. */
 	nhoff = fq->nhoffset;
-	skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
-	memmove(head->head + sizeof(struct frag_hdr), head->head,
-		(head->data - head->head) - sizeof(struct frag_hdr));
-	if (skb_mac_header_was_set(head))
-		head->mac_header += sizeof(struct frag_hdr);
-	head->network_header += sizeof(struct frag_hdr);
-
-	skb_reset_transport_header(head);
-	skb_push(head, head->data - skb_network_header(head));
-
-	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);
-
-		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;
-	}
-	sub_frag_mem_limit(fq->q.net, sum_truesize);
+	skb_network_header(skb)[nhoff] = skb_transport_header(skb)[0];
+	memmove(skb->head + sizeof(struct frag_hdr), skb->head,
+		(skb->data - skb->head) - sizeof(struct frag_hdr));
+	if (skb_mac_header_was_set(skb))
+		skb->mac_header += sizeof(struct frag_hdr);
+	skb->network_header += sizeof(struct frag_hdr);
+
+	skb_reset_transport_header(skb);
 
-	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;
+	inet_frag_reasm_finish(&fq->q, skb, reasm_data);
+
+	skb->dev = dev;
+	ipv6_hdr(skb)->payload_len = htons(payload_len);
+	ipv6_change_dsfield(ipv6_hdr(skb), 0xff, ecn);
+	IP6CB(skb)->nhoff = nhoff;
+	IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
+	IP6CB(skb)->frag_max_size = fq->q.max_size;
 
 	/* Yes, and fold redundant checksum back. 8) */
-	skb_postpush_rcsum(head, skb_network_header(head),
-			   skb_network_header_len(head));
+	skb_postpush_rcsum(skb, skb_network_header(skb),
+			   skb_network_header_len(skb));
 
 	rcu_read_lock();
 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
@@ -468,6 +306,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 	fq->q.fragments = NULL;
 	fq->q.rb_fragments = RB_ROOT;
 	fq->q.fragments_tail = NULL;
+	fq->q.last_run_head = NULL;
 	return 1;
 
 out_oversize:
@@ -479,6 +318,7 @@ out_fail:
 	rcu_read_lock();
 	__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 	rcu_read_unlock();
+	inet_frag_kill(&fq->q);
 	return -1;
 }
 
@@ -517,22 +357,26 @@ static int ipv6_frag_rcv(struct sk_buff *skb)
 		return 1;
 	}
 
-	if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU &&
-	    fhdr->frag_off & htons(IP6_MF))
-		goto fail_hdr;
-
 	iif = skb->dev ? skb->dev->ifindex : 0;
 	fq = fq_find(net, fhdr->identification, hdr, iif);
 	if (fq) {
+		u32 prob_offset = 0;
 		int ret;
 
 		spin_lock(&fq->q.lock);
 
 		fq->iif = iif;
-		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
+		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff,
+				     &prob_offset);
 
 		spin_unlock(&fq->q.lock);
 		inet_frag_put(&fq->q);
+		if (prob_offset) {
+			__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
+					IPSTATS_MIB_INHDRERRORS);
+			/* icmpv6_param_prob() calls kfree_skb(skb) */
+			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, prob_offset);
+		}
 		return ret;
 	}
 
@@ -700,42 +544,19 @@ static struct pernet_operations ip6_frags_ops = {
 	.exit = ipv6_frags_exit_net,
 };
 
-static u32 ip6_key_hashfn(const void *data, u32 len, u32 seed)
-{
-	return jhash2(data,
-		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
-}
-
-static u32 ip6_obj_hashfn(const void *data, u32 len, u32 seed)
-{
-	const struct inet_frag_queue *fq = data;
-
-	return jhash2((const u32 *)&fq->key.v6,
-		      sizeof(struct frag_v6_compare_key) / sizeof(u32), seed);
-}
-
-static int ip6_obj_cmpfn(struct rhashtable_compare_arg *arg, const void *ptr)
-{
-	const struct frag_v6_compare_key *key = arg->key;
-	const struct inet_frag_queue *fq = ptr;
-
-	return !!memcmp(&fq->key, key, sizeof(*key));
-}
-
-const struct rhashtable_params ip6_rhash_params = {
+static const struct rhashtable_params ip6_rhash_params = {
 	.head_offset		= offsetof(struct inet_frag_queue, node),
-	.hashfn			= ip6_key_hashfn,
-	.obj_hashfn		= ip6_obj_hashfn,
-	.obj_cmpfn		= ip6_obj_cmpfn,
+	.hashfn			= ip6frag_key_hashfn,
+	.obj_hashfn		= ip6frag_obj_hashfn,
+	.obj_cmpfn		= ip6frag_obj_cmpfn,
 	.automatic_shrinking	= true,
 };
-EXPORT_SYMBOL(ip6_rhash_params);
 
 int __init ipv6_frag_init(void)
 {
 	int ret;
 
-	ip6_frags.constructor = ip6_frag_init;
+	ip6_frags.constructor = ip6frag_init;
 	ip6_frags.destructor = NULL;
 	ip6_frags.qsize = sizeof(struct frag_queue);
 	ip6_frags.frag_expire = ip6_frag_expire;
@@ -771,8 +592,8 @@ err_protocol:
 
 void ipv6_frag_exit(void)
 {
-	inet_frags_fini(&ip6_frags);
 	ip6_frags_sysctl_unregister();
 	unregister_pernet_subsys(&ip6_frags_ops);
 	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+	inet_frags_fini(&ip6_frags);
 }