2 files changed, 70 insertions, 32 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index dbcda7e868b..93a30ae8d07 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -44,8 +44,6 @@ static int ccid2_debug;
 #define ccid2_pr_debug(format, a...)
 #endif
 
-static const int ccid2_seq_len = 128;
-
 #ifdef CONFIG_IP_DCCP_CCID2_DEBUG
 static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 {
@@ -71,7 +69,6 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 			BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq);
 			BUG_ON(time_before(seqp->ccid2s_sent,
 					   prev->ccid2s_sent));
-			BUG_ON(len > ccid2_seq_len);
 
 			seqp = prev;
 		}
@@ -83,16 +80,57 @@ static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx)
 	do {
 		seqp = seqp->ccid2s_prev;
 		len++;
-		BUG_ON(len > ccid2_seq_len);
 	} while (seqp != hctx->ccid2hctx_seqh);
 
-	BUG_ON(len != ccid2_seq_len);
 	ccid2_pr_debug("total len=%d\n", len);
+	BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN);
 }
 #else
 #define ccid2_hc_tx_check_sanity(hctx) do {} while (0)
 #endif
 
+static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num,
+				 gfp_t gfp)
+{
+	struct ccid2_seq *seqp;
+	int i;
+
+	/* check if we have space to preserve the pointer to the buffer */
+	if (hctx->ccid2hctx_seqbufc >= (sizeof(hctx->ccid2hctx_seqbuf) /
+					sizeof(struct ccid2_seq*)))
+		return -ENOMEM;
+
+	/* allocate buffer and initialize linked list */
+	seqp = kmalloc(sizeof(*seqp) * num, gfp);
+	if (seqp == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < (num - 1); i++) {
+		seqp[i].ccid2s_next = &seqp[i + 1];
+		seqp[i + 1].ccid2s_prev = &seqp[i];
+	}
+	seqp[num - 1].ccid2s_next = seqp;
+	seqp->ccid2s_prev = &seqp[num - 1];
+
+	/* This is the first allocation.  Initiate the head and tail.  */
+	if (hctx->ccid2hctx_seqbufc == 0)
+		hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqt = seqp;
+	else {
+		/* link the existing list with the one we just created */
+		hctx->ccid2hctx_seqh->ccid2s_next = seqp;
+		seqp->ccid2s_prev = hctx->ccid2hctx_seqh;
+
+		hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[num - 1];
+		seqp[num - 1].ccid2s_next = hctx->ccid2hctx_seqt;
+	}
+
+	/* store the original pointer to the buffer so we can free it */
+	hctx->ccid2hctx_seqbuf[hctx->ccid2hctx_seqbufc] = seqp;
+	hctx->ccid2hctx_seqbufc++;
+
+	return 0;
+}
+
 static int ccid2_hc_tx_send_packet(struct sock *sk,
 				   struct sk_buff *skb, int len)
 {
@@ -231,6 +269,7 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 	struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+	struct ccid2_seq *next;
 	u64 seq;
 
 	ccid2_hc_tx_check_sanity(hctx);
@@ -250,15 +289,23 @@ static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, int len)
 	hctx->ccid2hctx_seqh->ccid2s_seq   = seq;
 	hctx->ccid2hctx_seqh->ccid2s_acked = 0;
 	hctx->ccid2hctx_seqh->ccid2s_sent  = jiffies;
-	hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqh->ccid2s_next;
 
-	ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd,
-		       hctx->ccid2hctx_pipe);
+	next = hctx->ccid2hctx_seqh->ccid2s_next;
+	/* check if we need to alloc more space */
+	if (next == hctx->ccid2hctx_seqt) {
+		int rc;
 
-	if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) {
-		/* XXX allocate more space */
-		WARN_ON(1);
+		ccid2_pr_debug("allocating more space in history\n");
+		rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_KERNEL);
+		BUG_ON(rc); /* XXX what do we do? */
+
+		next = hctx->ccid2hctx_seqh->ccid2s_next;
+		BUG_ON(next == hctx->ccid2hctx_seqt);
 	}
+	hctx->ccid2hctx_seqh = next;
+
+	ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd,
+		       hctx->ccid2hctx_pipe);
 
 	hctx->ccid2hctx_sent++;
 
@@ -674,8 +721,6 @@ static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 {
         struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid);
-	int seqcount = ccid2_seq_len;
-	int i;
 
 	hctx->ccid2hctx_cwnd	  = 1;
 	/* Initialize ssthresh to infinity.  This means that we will exit the
@@ -684,26 +729,12 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 	 */
 	hctx->ccid2hctx_ssthresh  = ~0;
 	hctx->ccid2hctx_numdupack = 3;
+	hctx->ccid2hctx_seqbufc   = 0;
 
 	/* XXX init ~ to window size... */
-	hctx->ccid2hctx_seqbuf = kmalloc(sizeof(*hctx->ccid2hctx_seqbuf) *
-					 seqcount, gfp_any());
-	if (hctx->ccid2hctx_seqbuf == NULL)
+	if (ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0)
 		return -ENOMEM;
 
-	for (i = 0; i < (seqcount - 1); i++) {
-		hctx->ccid2hctx_seqbuf[i].ccid2s_next =
-					&hctx->ccid2hctx_seqbuf[i + 1];
-		hctx->ccid2hctx_seqbuf[i + 1].ccid2s_prev =
-					&hctx->ccid2hctx_seqbuf[i];
-	}
-	hctx->ccid2hctx_seqbuf[seqcount - 1].ccid2s_next =
-					hctx->ccid2hctx_seqbuf;
-	hctx->ccid2hctx_seqbuf->ccid2s_prev =
-					&hctx->ccid2hctx_seqbuf[seqcount - 1];
-
-	hctx->ccid2hctx_seqh	 = hctx->ccid2hctx_seqbuf;
-	hctx->ccid2hctx_seqt	 = hctx->ccid2hctx_seqh;
 	hctx->ccid2hctx_sent	 = 0;
 	hctx->ccid2hctx_rto	 = 3 * HZ;
 	hctx->ccid2hctx_srtt	 = -1;
@@ -722,10 +753,13 @@ static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk)
 static void ccid2_hc_tx_exit(struct sock *sk)
 {
         struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk);
+	int i;
 
 	ccid2_hc_tx_kill_rto_timer(sk);
-	kfree(hctx->ccid2hctx_seqbuf);
-	hctx->ccid2hctx_seqbuf = NULL;
+
+	for (i = 0; i < hctx->ccid2hctx_seqbufc; i++)
+		kfree(hctx->ccid2hctx_seqbuf[i]);
+	hctx->ccid2hctx_seqbufc = 0;
 }
 
 static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
diff --git a/net/dccp/ccids/ccid2.h b/net/dccp/ccids/ccid2.h
index b4cc6c0bf02..2a02ce04ba8 100644
--- a/net/dccp/ccids/ccid2.h
+++ b/net/dccp/ccids/ccid2.h
@@ -35,6 +35,9 @@ struct ccid2_seq {
 	struct ccid2_seq	*ccid2s_next;
 };
 
+#define CCID2_SEQBUF_LEN 256
+#define CCID2_SEQBUF_MAX 128
+
 /** struct ccid2_hc_tx_sock - CCID2 TX half connection
  *
  * @ccid2hctx_ssacks - ACKs recv in slow start
@@ -53,7 +56,8 @@ struct ccid2_hc_tx_sock {
 	unsigned int		ccid2hctx_ssthresh;
 	int			ccid2hctx_pipe;
 	int			ccid2hctx_numdupack;
-	struct ccid2_seq	*ccid2hctx_seqbuf;
+	struct ccid2_seq	*ccid2hctx_seqbuf[CCID2_SEQBUF_MAX];
+	int			ccid2hctx_seqbufc;
 	struct ccid2_seq	*ccid2hctx_seqh;
 	struct ccid2_seq	*ccid2hctx_seqt;
 	long			ccid2hctx_rto;