Re: Linux 2.6.16.15

[Chris Wright <chrisw@sous-sol.org>]

diff --git a/Makefile b/Makefile
index 3c03fb9..cdd3ce7 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 16
-EXTRAVERSION = .14
+EXTRAVERSION = .15
 NAME=Sliding Snow Leopard
 
 # *DOCUMENTATION*
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 072f407..acb2ce1 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -702,6 +702,7 @@ struct sctp_chunk {
 	__u8 tsn_gap_acked;	/* Is this chunk acked by a GAP ACK? */
 	__s8 fast_retransmit;	 /* Is this chunk fast retransmitted? */
 	__u8 tsn_missing_report; /* Data chunk missing counter. */
+	__u8 data_accepted; 	/* At least 1 chunk in this packet accepted */
 };
 
 void sctp_chunk_hold(struct sctp_chunk *);
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index 297b895..cf0c767 100644
--- a/net/sctp/inqueue.c
+++ b/net/sctp/inqueue.c
@@ -149,6 +149,7 @@ struct sctp_chunk *sctp_inq_pop(struct s
 		/* This is the first chunk in the packet.  */
 		chunk->singleton = 1;
 		ch = (sctp_chunkhdr_t *) chunk->skb->data;
+		chunk->data_accepted = 0;
 	}
 
         chunk->chunk_hdr = ch;
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 2b9a832..8cdba51 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -636,8 +636,9 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(co
 	 */
         chunk->subh.cookie_hdr =
 		(struct sctp_signed_cookie *)chunk->skb->data;
-	skb_pull(chunk->skb,
-		 ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t));
+	if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+					 sizeof(sctp_chunkhdr_t)))
+		goto nomem;
 
 	/* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
 	 * "Z" will reply with a COOKIE ACK chunk after building a TCB
@@ -965,7 +966,8 @@ sctp_disposition_t sctp_sf_beat_8_3(cons
 	 */
 	chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
 	paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
-	skb_pull(chunk->skb, paylen);
+	if (!pskb_pull(chunk->skb, paylen))
+		goto nomem;
 
 	reply = sctp_make_heartbeat_ack(asoc, chunk,
 					chunk->subh.hb_hdr, paylen);
@@ -1860,8 +1862,9 @@ sctp_disposition_t sctp_sf_do_5_2_4_dupc
 	 * are in good shape.
 	 */
         chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
-	skb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
-		 sizeof(sctp_chunkhdr_t));
+	if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
+					sizeof(sctp_chunkhdr_t)))
+		goto nomem;
 
 	/* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
 	 * of a duplicate COOKIE ECHO match the Verification Tags of the
@@ -5151,7 +5154,9 @@ static int sctp_eat_data(const struct sc
 	int tmp;
 	__u32 tsn;
 	int account_value;
+	struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
 	struct sock *sk = asoc->base.sk;
+	int rcvbuf_over = 0;
 
 	data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
 	skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
@@ -5162,10 +5167,16 @@ static int sctp_eat_data(const struct sc
 	/* ASSERT:  Now skb->data is really the user data.  */
 
 	/*
-	 * if we are established, and we have used up our receive
-	 * buffer memory, drop the frame
-	 */
-	if (asoc->state == SCTP_STATE_ESTABLISHED) {
+	 * If we are established, and we have used up our receive buffer
+	 * memory, think about droping the frame.
+	 * Note that we have an opportunity to improve performance here.
+	 * If we accept one chunk from an skbuff, we have to keep all the
+	 * memory of that skbuff around until the chunk is read into user
+	 * space. Therefore, once we accept 1 chunk we may as well accept all
+	 * remaining chunks in the skbuff. The data_accepted flag helps us do
+	 * that.
+	 */
+	if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
 		/*
 		 * If the receive buffer policy is 1, then each
 		 * association can allocate up to sk_rcvbuf bytes
@@ -5176,9 +5187,25 @@ static int sctp_eat_data(const struct sc
 			account_value = atomic_read(&asoc->rmem_alloc);
 		else
 			account_value = atomic_read(&sk->sk_rmem_alloc);
-
-		if (account_value > sk->sk_rcvbuf)
-			return SCTP_IERROR_IGNORE_TSN;
+		if (account_value > sk->sk_rcvbuf) {
+			/*
+			 * We need to make forward progress, even when we are
+			 * under memory pressure, so we always allow the
+			 * next tsn after the ctsn ack point to be accepted.
+			 * This lets us avoid deadlocks in which we have to
+			 * drop frames that would otherwise let us drain the
+			 * receive queue.
+			 */
+			if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
+				return SCTP_IERROR_IGNORE_TSN;
+
+			/*
+			 * We're going to accept the frame but we should renege
+			 * to make space for it. This will send us down that
+			 * path later in this function.
+			 */
+			rcvbuf_over = 1;
+		}
 	}
 
 	/* Process ECN based congestion.
@@ -5226,6 +5253,7 @@ static int sctp_eat_data(const struct sc
 	datalen -= sizeof(sctp_data_chunk_t);
 
 	deliver = SCTP_CMD_CHUNK_ULP;
+	chunk->data_accepted = 1;
 
 	/* Think about partial delivery. */
 	if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
@@ -5242,7 +5270,8 @@ static int sctp_eat_data(const struct sc
 	 * large spill over.
 	 */
 	if (!asoc->rwnd || asoc->rwnd_over ||
-	    (datalen > asoc->rwnd + asoc->frag_point)) {
+	    (datalen > asoc->rwnd + asoc->frag_point) ||
+	    rcvbuf_over) {
 
 		/* If this is the next TSN, consider reneging to make
 		 * room.   Note: Playing nice with a confused sender.  A
@@ -5250,8 +5279,8 @@ static int sctp_eat_data(const struct sc
 		 * space and in the future we may want to detect and
 		 * do more drastic reneging.
 		 */
-		if (sctp_tsnmap_has_gap(&asoc->peer.tsn_map) &&
-		    (sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1) == tsn) {
+		if (sctp_tsnmap_has_gap(map) &&
+		    (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
 			SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
 			deliver = SCTP_CMD_RENEGE;
 		} else {
diff --git a/net/sctp/sm_statetable.c b/net/sctp/sm_statetable.c
index 75ef104..8bcca56 100644
--- a/net/sctp/sm_statetable.c
+++ b/net/sctp/sm_statetable.c
@@ -366,9 +366,9 @@ #define TYPE_SCTP_ECN_ECNE { \
 	/* SCTP_STATE_EMPTY */ \
 	{.fn = sctp_sf_ootb, .name = "sctp_sf_ootb"}, \
 	/* SCTP_STATE_CLOSED */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
+	{.fn = sctp_sf_discard_chunk, .name = "sctp_sf_discard_chunk"}, \
 	/* SCTP_STATE_COOKIE_WAIT */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
+	{.fn = sctp_sf_discard_chunk, .name = "sctp_sf_discard_chunk"}, \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
 	{.fn = sctp_sf_do_ecne, .name = "sctp_sf_do_ecne"}, \
 	/* SCTP_STATE_ESTABLISHED */ \
@@ -380,7 +380,7 @@ #define TYPE_SCTP_ECN_ECNE { \
 	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
 	{.fn = sctp_sf_do_ecne, .name = "sctp_sf_do_ecne"}, \
 	/* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
+	{.fn = sctp_sf_discard_chunk, .name = "sctp_sf_discard_chunk"}, \
 } /* TYPE_SCTP_ECN_ECNE */
 
 #define TYPE_SCTP_ECN_CWR { \
@@ -401,7 +401,7 @@ #define TYPE_SCTP_ECN_CWR { \
 	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
 	{.fn = sctp_sf_discard_chunk, .name = "sctp_sf_discard_chunk"}, \
 	/* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
+	{.fn = sctp_sf_discard_chunk, .name = "sctp_sf_discard_chunk"}, \
 } /* TYPE_SCTP_ECN_CWR */
 
 #define TYPE_SCTP_SHUTDOWN_COMPLETE { \
@@ -647,7 +647,7 @@ #define TYPE_SCTP_PRIMITIVE_REQUESTHEART
 	/* SCTP_STATE_EMPTY */ \
 	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
 	/* SCTP_STATE_CLOSED */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
+	{.fn = sctp_sf_error_closed, .name = "sctp_sf_error_closed"}, \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	{.fn = sctp_sf_do_prm_requestheartbeat,		      \
 	 .name = "sctp_sf_do_prm_requestheartbeat"},          \
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
index 2080b2d..575e556 100644
--- a/net/sctp/ulpqueue.c
+++ b/net/sctp/ulpqueue.c
@@ -279,6 +279,7 @@ static inline void sctp_ulpq_store_reasm
 static struct sctp_ulpevent *sctp_make_reassembled_event(struct sk_buff_head *queue, struct sk_buff *f_frag, struct sk_buff *l_frag)
 {
 	struct sk_buff *pos;
+	struct sk_buff *new = NULL;
 	struct sctp_ulpevent *event;
 	struct sk_buff *pnext, *last;
 	struct sk_buff *list = skb_shinfo(f_frag)->frag_list;
@@ -297,11 +298,33 @@ static struct sctp_ulpevent *sctp_make_r
 	 */
 	if (last)
 		last->next = pos;
-	else
-		skb_shinfo(f_frag)->frag_list = pos;
+ 	else {
+ 		if (skb_cloned(f_frag)) {
+ 			/* This is a cloned skb, we can't just modify
+ 			 * the frag_list.  We need a new skb to do that.
+ 			 * Instead of calling skb_unshare(), we'll do it
+ 			 * ourselves since we need to delay the free.
+ 			 */
+ 			new = skb_copy(f_frag, GFP_ATOMIC);
+ 			if (!new)
+ 				return NULL;	/* try again later */
+
+ 			new->sk = f_frag->sk;
+
+ 			skb_shinfo(new)->frag_list = pos;
+ 		} else
+ 			skb_shinfo(f_frag)->frag_list = pos;
+ 	}
 
 	/* Remove the first fragment from the reassembly queue.  */
 	__skb_unlink(f_frag, queue);
+
+ 	/* if we did unshare, then free the old skb and re-assign */
+ 	if (new) {
+ 		kfree_skb(f_frag);
+ 		f_frag = new;
+ 	}
+
 	while (pos) {
 
 		pnext = pos->next;
-
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