X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=net%2Fsctp%2Finput.c;fp=net%2Fsctp%2Finput.c;h=2325fee8574819498067979aef55bfcd353c9a0a;hb=64ba3f394c830ec48a1c31b53dcae312c56f1604;hp=2060bbeb30148135735e9587feb40a4cd00c9d18;hpb=be1e6109ac94a859551f8e1774eb9a8469fe055c;p=linux-2.6.git

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 2060bbeb3..2325fee85 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -73,8 +73,6 @@ static struct sctp_association *__sctp_lookup_association(
 					const union sctp_addr *peer,
 					struct sctp_transport **pt);
 
-static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb);
-
 
 /* Calculate the SCTP checksum of an SCTP packet.  */
 static inline int sctp_rcv_checksum(struct sk_buff *skb)
@@ -129,13 +127,14 @@ int sctp_rcv(struct sk_buff *skb)
 	union sctp_addr dest;
 	int family;
 	struct sctp_af *af;
+	int ret = 0;
 
 	if (skb->pkt_type!=PACKET_HOST)
 		goto discard_it;
 
 	SCTP_INC_STATS_BH(SCTP_MIB_INSCTPPACKS);
 
-	if (skb_linearize(skb))
+	if (skb_linearize(skb, GFP_ATOMIC))
 		goto discard_it;
 
 	sh = (struct sctphdr *) skb->h.raw;
@@ -144,8 +143,7 @@ int sctp_rcv(struct sk_buff *skb)
 	__skb_pull(skb, skb->h.raw - skb->data);
 	if (skb->len < sizeof(struct sctphdr))
 		goto discard_it;
-	if ((skb->ip_summed != CHECKSUM_UNNECESSARY) &&
-	    (sctp_rcv_checksum(skb) < 0))
+	if (sctp_rcv_checksum(skb) < 0)
 		goto discard_it;
 
 	skb_pull(skb, sizeof(struct sctphdr));
@@ -193,6 +191,7 @@ int sctp_rcv(struct sk_buff *skb)
 	 */
 	if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb)))
 	{
+		sock_put(sk);
 		if (asoc) {
 			sctp_association_put(asoc);
 			asoc = NULL;
@@ -203,6 +202,7 @@ int sctp_rcv(struct sk_buff *skb)
 		sk = sctp_get_ctl_sock();
 		ep = sctp_sk(sk)->ep;
 		sctp_endpoint_hold(ep);
+		sock_hold(sk);
 		rcvr = &ep->base;
 	}
 
@@ -231,13 +231,16 @@ int sctp_rcv(struct sk_buff *skb)
 		goto discard_release;
 	nf_reset(skb);
 
-	if (sk_filter(sk, skb, 1))
+	ret = sk_filter(sk, skb, 1);
+	if (ret)
                 goto discard_release;
 
 	/* Create an SCTP packet structure. */
 	chunk = sctp_chunkify(skb, asoc, sk);
-	if (!chunk)
+	if (!chunk) {
+		ret = -ENOMEM;
 		goto discard_release;
+	}
 	SCTP_INPUT_CB(skb)->chunk = chunk;
 
 	/* Remember what endpoint is to handle this packet. */
@@ -258,27 +261,35 @@ int sctp_rcv(struct sk_buff *skb)
 	 */
 	sctp_bh_lock_sock(sk);
 
+	/* It is possible that the association could have moved to a different
+	 * socket if it is peeled off. If so, update the sk.
+	 */ 
+	if (sk != rcvr->sk) {
+		sctp_bh_lock_sock(rcvr->sk);
+		sctp_bh_unlock_sock(sk);
+		sk = rcvr->sk;
+	}
+
 	if (sock_owned_by_user(sk))
-		sctp_add_backlog(sk, skb);
+		sk_add_backlog(sk, skb);
 	else
-		sctp_inq_push(&chunk->rcvr->inqueue, chunk);
+		sctp_backlog_rcv(sk, skb);
 
+	/* Release the sock and the sock ref we took in the lookup calls.
+	 * The asoc/ep ref will be released in sctp_backlog_rcv.
+	 */
 	sctp_bh_unlock_sock(sk);
+	sock_put(sk);
 
-	/* Release the asoc/ep ref we took in the lookup calls. */
-	if (asoc)
-		sctp_association_put(asoc);
-	else
-		sctp_endpoint_put(ep);
-
-	return 0;
+	return ret;
 
 discard_it:
 	kfree_skb(skb);
-	return 0;
+	return ret;
 
 discard_release:
-	/* Release the asoc/ep ref we took in the lookup calls. */
+	/* Release any structures we may be holding. */
+	sock_put(sk);
 	if (asoc)
 		sctp_association_put(asoc);
 	else
@@ -287,87 +298,56 @@ discard_release:
 	goto discard_it;
 }
 
-/* Process the backlog queue of the socket.  Every skb on
- * the backlog holds a ref on an association or endpoint.
- * We hold this ref throughout the state machine to make
- * sure that the structure we need is still around.
+/* Handle second half of inbound skb processing.  If the sock was busy,
+ * we may have need to delay processing until later when the sock is
+ * released (on the backlog).   If not busy, we call this routine
+ * directly from the bottom half.
  */
 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
- 	struct sctp_inq *inqueue = &chunk->rcvr->inqueue;
+ 	struct sctp_inq *inqueue = NULL;
  	struct sctp_ep_common *rcvr = NULL;
-	int backloged = 0;
 
  	rcvr = chunk->rcvr;
 
-	/* If the rcvr is dead then the association or endpoint
-	 * has been deleted and we can safely drop the chunk
-	 * and refs that we are holding.
-	 */
-	if (rcvr->dead) {
-		sctp_chunk_free(chunk);
-		goto done;
-	}
-
-	if (unlikely(rcvr->sk != sk)) {
-		/* In this case, the association moved from one socket to
-		 * another.  We are currently sitting on the backlog of the
-		 * old socket, so we need to move.
-		 * However, since we are here in the process context we
-		 * need to take make sure that the user doesn't own
-		 * the new socket when we process the packet.
-		 * If the new socket is user-owned, queue the chunk to the
-		 * backlog of the new socket without dropping any refs.
-		 * Otherwise, we can safely push the chunk on the inqueue.
-		 */
-
-		sk = rcvr->sk;
-		sctp_bh_lock_sock(sk);
-
-		if (sock_owned_by_user(sk)) {
-			sk_add_backlog(sk, skb);
-			backloged = 1;
-		} else
-			sctp_inq_push(inqueue, chunk);
-
-		sctp_bh_unlock_sock(sk);
-
-		/* If the chunk was backloged again, don't drop refs */
-		if (backloged)
-			return 0;
-	} else {
-		sctp_inq_push(inqueue, chunk);
-	}
-
-done:
-	/* Release the refs we took in sctp_add_backlog */
-	if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
-		sctp_association_put(sctp_assoc(rcvr));
-	else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
-		sctp_endpoint_put(sctp_ep(rcvr));
-	else
-		BUG();
-
+	BUG_TRAP(rcvr->sk == sk);
+
+ 	if (rcvr->dead) {
+ 		sctp_chunk_free(chunk);
+ 	} else {
+ 		inqueue = &chunk->rcvr->inqueue;
+ 		sctp_inq_push(inqueue, chunk);
+ 	}
+
+	/* Release the asoc/ep ref we took in the lookup calls in sctp_rcv. */ 
+ 	if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
+ 		sctp_association_put(sctp_assoc(rcvr));
+ 	else
+ 		sctp_endpoint_put(sctp_ep(rcvr));
+  
         return 0;
 }
 
-static void sctp_add_backlog(struct sock *sk, struct sk_buff *skb)
+void sctp_backlog_migrate(struct sctp_association *assoc, 
+			  struct sock *oldsk, struct sock *newsk)
 {
-	struct sctp_chunk *chunk = SCTP_INPUT_CB(skb)->chunk;
-	struct sctp_ep_common *rcvr = chunk->rcvr;
-
-	/* Hold the assoc/ep while hanging on the backlog queue.
-	 * This way, we know structures we need will not disappear from us
-	 */
-	if (SCTP_EP_TYPE_ASSOCIATION == rcvr->type)
-		sctp_association_hold(sctp_assoc(rcvr));
-	else if (SCTP_EP_TYPE_SOCKET == rcvr->type)
-		sctp_endpoint_hold(sctp_ep(rcvr));
-	else
-		BUG();
+	struct sk_buff *skb;
+	struct sctp_chunk *chunk;
 
-	sk_add_backlog(sk, skb);
+	skb = oldsk->sk_backlog.head;
+	oldsk->sk_backlog.head = oldsk->sk_backlog.tail = NULL;
+	while (skb != NULL) {
+		struct sk_buff *next = skb->next;
+
+		chunk = SCTP_INPUT_CB(skb)->chunk;
+		skb->next = NULL;
+		if (&assoc->base == chunk->rcvr)
+			sk_add_backlog(newsk, skb);
+		else
+			sk_add_backlog(oldsk, skb);
+		skb = next;
+	}
 }
 
 /* Handle icmp frag needed error. */
@@ -440,7 +420,7 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb,
 	union sctp_addr daddr;
 	struct sctp_af *af;
 	struct sock *sk = NULL;
-	struct sctp_association *asoc;
+	struct sctp_association *asoc = NULL;
 	struct sctp_transport *transport = NULL;
 
 	*app = NULL; *tpp = NULL;
@@ -481,6 +461,7 @@ struct sock *sctp_err_lookup(int family, struct sk_buff *skb,
 	return sk;
 
 out:
+	sock_put(sk);
 	if (asoc)
 		sctp_association_put(asoc);
 	return NULL;
@@ -490,6 +471,7 @@ out:
 void sctp_err_finish(struct sock *sk, struct sctp_association *asoc)
 {
 	sctp_bh_unlock_sock(sk);
+	sock_put(sk);
 	if (asoc)
 		sctp_association_put(asoc);
 }
@@ -516,7 +498,7 @@ void sctp_v4_err(struct sk_buff *skb, __u32 info)
 	int type = skb->h.icmph->type;
 	int code = skb->h.icmph->code;
 	struct sock *sk;
-	struct sctp_association *asoc = NULL;
+	struct sctp_association *asoc;
 	struct sctp_transport *transport;
 	struct inet_sock *inet;
 	char *saveip, *savesctp;
@@ -742,6 +724,7 @@ static struct sctp_endpoint *__sctp_rcv_lookup_endpoint(const union sctp_addr *l
 
 hit:
 	sctp_endpoint_hold(ep);
+	sock_hold(epb->sk);
 	read_unlock(&head->lock);
 	return ep;
 }
@@ -843,6 +826,7 @@ static struct sctp_association *__sctp_lookup_association(
 hit:
 	*pt = transport;
 	sctp_association_hold(asoc);
+	sock_hold(epb->sk);
 	read_unlock(&head->lock);
 	return asoc;
 }
@@ -870,6 +854,7 @@ int sctp_has_association(const union sctp_addr *laddr,
 	struct sctp_transport *transport;
 
 	if ((asoc = sctp_lookup_association(laddr, paddr, &transport))) {
+		sock_put(asoc->base.sk);
 		sctp_association_put(asoc);
 		return 1;
 	}