1 files changed, 194 insertions, 102 deletions

diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index 2c77dafbd091..b5981e5f6b00 100644
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -13,36 +13,83 @@
 #include "dccp.h"
 
 #include <linux/dccp.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 
 #include <net/sock.h>
 
+static kmem_cache_t *dccp_ackvec_slab;
+static kmem_cache_t *dccp_ackvec_record_slab;
+
+static struct dccp_ackvec_record *dccp_ackvec_record_new(void)
+{
+        struct dccp_ackvec_record *avr =
+                        kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
+
+        if (avr != NULL)
+                INIT_LIST_HEAD(&avr->dccpavr_node);
+
+        return avr;
+}
+
+static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr)
+{
+        if (unlikely(avr == NULL))
+                return;
+        /* Check if deleting a linked record */
+        WARN_ON(!list_empty(&avr->dccpavr_node));
+        kmem_cache_free(dccp_ackvec_record_slab, avr);
+}
+
+static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
+                                   struct dccp_ackvec_record *avr)
+{
+        /*
+         * AVRs are sorted by seqno. Since we are sending them in order, we
+         * just add the AVR at the head of the list.
+         * -sorbo.
+         */
+        if (!list_empty(&av->dccpav_records)) {
+                const struct dccp_ackvec_record *head =
+                                        list_entry(av->dccpav_records.next,
+                                                   struct dccp_ackvec_record,
+                                                   dccpavr_node);
+                BUG_ON(before48(avr->dccpavr_ack_seqno,
+                                head->dccpavr_ack_seqno));
+        }
+
+        list_add(&avr->dccpavr_node, &av->dccpav_records);
+}
+
 int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 {
         struct dccp_sock *dp = dccp_sk(sk);
+#ifdef CONFIG_IP_DCCP_DEBUG
+        const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
+                                "CLIENT tx: " : "server tx: ";
+#endif
         struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
         int len = av->dccpav_vec_len + 2;
         struct timeval now;
         u32 elapsed_time;
         unsigned char *to, *from;
+        struct dccp_ackvec_record *avr;
+
+        if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
+                return -1;
 
         dccp_timestamp(sk, &now);
         elapsed_time = timeval_delta(&now, &av->dccpav_time) / 10;
 
-        if (elapsed_time != 0)
-                dccp_insert_option_elapsed_time(sk, skb, elapsed_time);
-
-        if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
+        if (elapsed_time != 0 &&
+            dccp_insert_option_elapsed_time(sk, skb, elapsed_time))
                 return -1;
 
-        /*
-         * XXX: now we have just one ack vector sent record, so
-         * we have to wait for it to be cleared.
-         *
-         * Of course this is not acceptable, but this is just for
-         * basic testing now.
-         */
-        if (av->dccpav_ack_seqno != DCCP_MAX_SEQNO + 1)
+        avr = dccp_ackvec_record_new();
+        if (avr == NULL)
                 return -1;
 
         DCCP_SKB_CB(skb)->dccpd_opt_len += len;
@@ -55,8 +102,8 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
         from = av->dccpav_buf + av->dccpav_buf_head;
 
         /* Check if buf_head wraps */
-        if ((int)av->dccpav_buf_head + len > av->dccpav_vec_len) {
-                const u32 tailsize = av->dccpav_vec_len - av->dccpav_buf_head;
+        if ((int)av->dccpav_buf_head + len > DCCP_MAX_ACKVEC_LEN) {
+                const u32 tailsize = DCCP_MAX_ACKVEC_LEN - av->dccpav_buf_head;
 
                 memcpy(to, from, tailsize);
                 to   += tailsize;
@@ -73,45 +120,37 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
          *      sequence number it used for the ack packet; ack_ptr will equal
          *      buf_head; ack_ackno will equal buf_ackno; and ack_nonce will
          *      equal buf_nonce.
-         *
-         * This implemention uses just one ack record for now.
          */
-        av->dccpav_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
-        av->dccpav_ack_ptr   = av->dccpav_buf_head;
-        av->dccpav_ack_ackno = av->dccpav_buf_ackno;
-        av->dccpav_ack_nonce = av->dccpav_buf_nonce;
-        av->dccpav_sent_len  = av->dccpav_vec_len;
+        avr->dccpavr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
+        avr->dccpavr_ack_ptr   = av->dccpav_buf_head;
+        avr->dccpavr_ack_ackno = av->dccpav_buf_ackno;
+        avr->dccpavr_ack_nonce = av->dccpav_buf_nonce;
+        avr->dccpavr_sent_len  = av->dccpav_vec_len;
+
+        dccp_ackvec_insert_avr(av, avr);
 
         dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
                       "ack_ackno=%llu\n",
-                      debug_prefix, av->dccpav_sent_len,
-                      (unsigned long long)av->dccpav_ack_seqno,
-                      (unsigned long long)av->dccpav_ack_ackno);
-        return -1;
+                      debug_prefix, avr->dccpavr_sent_len,
+                      (unsigned long long)avr->dccpavr_ack_seqno,
+                      (unsigned long long)avr->dccpavr_ack_ackno);
+        return 0;
 }
 
-struct dccp_ackvec *dccp_ackvec_alloc(const unsigned int len,
-                                      const gfp_t priority)
+struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
 {
-        struct dccp_ackvec *av;
-
-        BUG_ON(len == 0);
+        struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority);
 
-        if (len > DCCP_MAX_ACKVEC_LEN)
-                return NULL;
-
-        av = kmalloc(sizeof(*av) + len, priority);
         if (av != NULL) {
-                av->dccpav_buf_len      = len;
                 av->dccpav_buf_head     =
-                        av->dccpav_buf_tail = av->dccpav_buf_len - 1;
-                av->dccpav_buf_ackno    =
-                        av->dccpav_ack_ackno = av->dccpav_ack_seqno = ~0LLU;
+                        av->dccpav_buf_tail = DCCP_MAX_ACKVEC_LEN - 1;
+                av->dccpav_buf_ackno    = DCCP_MAX_SEQNO + 1;
                 av->dccpav_buf_nonce = av->dccpav_buf_nonce = 0;
                 av->dccpav_ack_ptr      = 0;
                 av->dccpav_time.tv_sec  = 0;
                 av->dccpav_time.tv_usec = 0;
                 av->dccpav_sent_len     = av->dccpav_vec_len = 0;
+                INIT_LIST_HEAD(&av->dccpav_records);
         }
 
         return av;
@@ -119,7 +158,20 @@ struct dccp_ackvec *dccp_ackvec_alloc(const unsigned int len,
 
 void dccp_ackvec_free(struct dccp_ackvec *av)
 {
-        kfree(av);
+        if (unlikely(av == NULL))
+                return;
+
+        if (!list_empty(&av->dccpav_records)) {
+                struct dccp_ackvec_record *avr, *next;
+
+                list_for_each_entry_safe(avr, next, &av->dccpav_records,
+                                         dccpavr_node) {
+                        list_del_init(&avr->dccpavr_node);
+                        dccp_ackvec_record_delete(avr);
+                }
+        }
+
+        kmem_cache_free(dccp_ackvec_slab, av);
 }
 
 static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av,
@@ -146,7 +198,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
         unsigned int gap;
         long new_head;
 
-        if (av->dccpav_vec_len + packets > av->dccpav_buf_len)
+        if (av->dccpav_vec_len + packets > DCCP_MAX_ACKVEC_LEN)
                 return -ENOBUFS;
 
         gap      = packets - 1;
@@ -158,7 +210,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
                                gap + new_head + 1);
                         gap = -new_head;
                 }
-                new_head += av->dccpav_buf_len;
+                new_head += DCCP_MAX_ACKVEC_LEN;
         } 
 
         av->dccpav_buf_head = new_head;
@@ -251,7 +303,7 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
                                 goto out_duplicate;
 
                         delta -= len + 1;
-                        if (++index == av->dccpav_buf_len)
+                        if (++index == DCCP_MAX_ACKVEC_LEN)
                                 index = 0;
                 }
         }
@@ -259,7 +311,6 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
         av->dccpav_buf_ackno = ackno;
         dccp_timestamp(sk, &av->dccpav_time);
 out:
-        dccp_pr_debug("");
         return 0;
 
 out_duplicate:
@@ -297,44 +348,50 @@ void dccp_ackvec_print(const struct dccp_ackvec *av)
 }
 #endif
 
-static void dccp_ackvec_throw_away_ack_record(struct dccp_ackvec *av)
+static void dccp_ackvec_throw_record(struct dccp_ackvec *av,
+                                     struct dccp_ackvec_record *avr)
 {
-        /*
-         * As we're keeping track of the ack vector size (dccpav_vec_len) and
-         * the sent ack vector size (dccpav_sent_len) we don't need
-         * dccpav_buf_tail at all, but keep this code here as in the future
-         * we'll implement a vector of ack records, as suggested in
-         * draft-ietf-dccp-spec-11.txt Appendix A. -acme
-         */
-#if 0
-        u32 new_buf_tail = av->dccpav_ack_ptr + 1;
-        if (new_buf_tail >= av->dccpav_vec_len)
-                new_buf_tail -= av->dccpav_vec_len;
-        av->dccpav_buf_tail = new_buf_tail;
-#endif
-        av->dccpav_vec_len -= av->dccpav_sent_len;
+        struct dccp_ackvec_record *next;
+
+        av->dccpav_buf_tail = avr->dccpavr_ack_ptr - 1;
+        if (av->dccpav_buf_tail == 0)
+                av->dccpav_buf_tail = DCCP_MAX_ACKVEC_LEN - 1;
+
+        av->dccpav_vec_len -= avr->dccpavr_sent_len;
+
+        /* free records */
+        list_for_each_entry_safe_from(avr, next, &av->dccpav_records,
+                                      dccpavr_node) {
+                list_del_init(&avr->dccpavr_node);
+                dccp_ackvec_record_delete(avr);
+        }
 }
 
 void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
                                  const u64 ackno)
 {
-        /* Check if we actually sent an ACK vector */
-        if (av->dccpav_ack_seqno == DCCP_MAX_SEQNO + 1)
-                return;
+        struct dccp_ackvec_record *avr;
 
-        if (ackno == av->dccpav_ack_seqno) {
+        /*
+         * If we traverse backwards, it should be faster when we have large
+         * windows. We will be receiving ACKs for stuff we sent a while back
+         * -sorbo.
+         */
+        list_for_each_entry_reverse(avr, &av->dccpav_records, dccpavr_node) {
+                if (ackno == avr->dccpavr_ack_seqno) {
 #ifdef CONFIG_IP_DCCP_DEBUG
-                struct dccp_sock *dp = dccp_sk(sk);
-                const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
-                                        "CLIENT rx ack: " : "server rx ack: ";
+                        struct dccp_sock *dp = dccp_sk(sk);
+                        const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
+                                                "CLIENT rx ack: " : "server rx ack: ";
 #endif
-                dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
-                              "ack_ackno=%llu, ACKED!\n",
-                              debug_prefix, 1,
-                              (unsigned long long)av->dccpav_ack_seqno,
-                              (unsigned long long)av->dccpav_ack_ackno);
-                dccp_ackvec_throw_away_ack_record(av);
-                av->dccpav_ack_seqno = DCCP_MAX_SEQNO + 1;
+                        dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
+                                      "ack_ackno=%llu, ACKED!\n",
+                                      debug_prefix, 1,
+                                      (unsigned long long)avr->dccpavr_ack_seqno,
+                                      (unsigned long long)avr->dccpavr_ack_ackno);
+                        dccp_ackvec_throw_record(av, avr);
+                        break;
+                }
         }
 }
 
@@ -344,28 +401,20 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
                                             const unsigned char *vector)
 {
         unsigned char i;
+        struct dccp_ackvec_record *avr;
 
         /* Check if we actually sent an ACK vector */
-        if (av->dccpav_ack_seqno == DCCP_MAX_SEQNO + 1)
-                return;
-        /*
-         * We're in the receiver half connection, so if the received an ACK
-         * vector ackno (e.g. 50) before dccpav_ack_seqno (e.g. 52), we're
-         * not interested.
-         *
-         * Extra explanation with example:
-         * 
-         * if we received an ACK vector with ackno 50, it can only be acking
-         * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent).
-         */
-        /* dccp_pr_debug("is %llu < %llu? ", ackno, av->dccpav_ack_seqno); */
-        if (before48(ackno, av->dccpav_ack_seqno)) {
-                /* dccp_pr_debug_cat("yes\n"); */
+        if (list_empty(&av->dccpav_records))
                 return;
-        }
-        /* dccp_pr_debug_cat("no\n"); */
 
         i = len;
+        /*
+         * XXX
+         * I think it might be more efficient to work backwards. See comment on
+         * rcv_ackno. -sorbo.
+         */
+        avr = list_entry(av->dccpav_records.next, struct dccp_ackvec_record,
+                         dccpavr_node);
         while (i--) {
                 const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
                 u64 ackno_end_rl;
@@ -373,14 +422,20 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
                 dccp_set_seqno(&ackno_end_rl, ackno - rl);
 
                 /*
-                 * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl,
-                 * av->dccpav_ack_seqno, ackno);
+                 * If our AVR sequence number is greater than the ack, go
+                 * forward in the AVR list until it is not so.
                  */
-                if (between48(av->dccpav_ack_seqno, ackno_end_rl, ackno)) {
+                list_for_each_entry_from(avr, &av->dccpav_records,
+                                         dccpavr_node) {
+                        if (!after48(avr->dccpavr_ack_seqno, ackno))
+                                goto found;
+                }
+                /* End of the dccpav_records list, not found, exit */
+                break;
+found:
+                if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, ackno)) {
                         const u8 state = (*vector &
                                           DCCP_ACKVEC_STATE_MASK) >> 6;
-                        /* dccp_pr_debug_cat("yes\n"); */
-
                         if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {
 #ifdef CONFIG_IP_DCCP_DEBUG
                                 struct dccp_sock *dp = dccp_sk(sk);
@@ -393,19 +448,16 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
                                               "ACKED!\n",
                                               debug_prefix, len,
                                               (unsigned long long)
-                                              av->dccpav_ack_seqno,
+                                              avr->dccpavr_ack_seqno,
                                               (unsigned long long)
-                                              av->dccpav_ack_ackno);
-                                dccp_ackvec_throw_away_ack_record(av);
+                                              avr->dccpavr_ack_ackno);
+                                dccp_ackvec_throw_record(av, avr);
                         }
                         /*
-                         * If dccpav_ack_seqno was not received, no problem
-                         * we'll send another ACK vector.
+                         * If it wasn't received, continue scanning... we might
+                         * find another one.
                          */
-                        av->dccpav_ack_seqno = DCCP_MAX_SEQNO + 1;
-                        break;
                 }
-                /* dccp_pr_debug_cat("no\n"); */
 
                 dccp_set_seqno(&ackno, ackno_end_rl - 1);
                 ++vector;
@@ -424,3 +476,43 @@ int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
                                         len, value);
         return 0;
 }
+
+static char dccp_ackvec_slab_msg[] __initdata =
+        KERN_CRIT "DCCP: Unable to create ack vectors slab caches\n";
+
+int __init dccp_ackvec_init(void)
+{
+        dccp_ackvec_slab = kmem_cache_create("dccp_ackvec",
+                                             sizeof(struct dccp_ackvec), 0,
+                                             SLAB_HWCACHE_ALIGN, NULL, NULL);
+        if (dccp_ackvec_slab == NULL)
+                goto out_err;
+
+        dccp_ackvec_record_slab =
+                        kmem_cache_create("dccp_ackvec_record",
+                                          sizeof(struct dccp_ackvec_record),
+                                          0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+        if (dccp_ackvec_record_slab == NULL)
+                goto out_destroy_slab;
+
+        return 0;
+
+out_destroy_slab:
+        kmem_cache_destroy(dccp_ackvec_slab);
+        dccp_ackvec_slab = NULL;
+out_err:
+        printk(dccp_ackvec_slab_msg);
+        return -ENOBUFS;
+}
+
+void dccp_ackvec_exit(void)
+{
+        if (dccp_ackvec_slab != NULL) {
+                kmem_cache_destroy(dccp_ackvec_slab);
+                dccp_ackvec_slab = NULL;
+        }
+        if (dccp_ackvec_record_slab != NULL) {
+                kmem_cache_destroy(dccp_ackvec_record_slab);
+                dccp_ackvec_record_slab = NULL;
+        }
+}