2 files changed, 70 insertions, 32 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index dbcda7e868b7..93a30ae8d07a 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 b4cc6c0bf020..2a02ce04ba85 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;