fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / net / dccp / ackvec.c
index 8c211c5..a086c63 100644 (file)
@@ -21,8 +21,8 @@
 
 #include <net/sock.h>
 
-static kmem_cache_t *dccp_ackvec_slab;
-static kmem_cache_t *dccp_ackvec_record_slab;
+static struct kmem_cache *dccp_ackvec_slab;
+static struct kmem_cache *dccp_ackvec_record_slab;
 
 static struct dccp_ackvec_record *dccp_ackvec_record_new(void)
 {
@@ -67,15 +67,16 @@ static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
 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;
+       /* Figure out how many options do we need to represent the ackvec */
+       const u16 nr_opts = (av->dccpav_vec_len +
+                            DCCP_MAX_ACKVEC_OPT_LEN - 1) /
+                           DCCP_MAX_ACKVEC_OPT_LEN;
+       u16 len = av->dccpav_vec_len + 2 * nr_opts, i;
        struct timeval now;
        u32 elapsed_time;
-       unsigned char *to, *from;
+       const unsigned char *tail, *from;
+       unsigned char *to;
        struct dccp_ackvec_record *avr;
 
        if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
@@ -94,26 +95,39 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 
        DCCP_SKB_CB(skb)->dccpd_opt_len += len;
 
-       to    = skb_push(skb, len);
-       *to++ = DCCPO_ACK_VECTOR_0;
-       *to++ = len;
-
+       to   = skb_push(skb, len);
        len  = av->dccpav_vec_len;
        from = av->dccpav_buf + av->dccpav_buf_head;
+       tail = av->dccpav_buf + DCCP_MAX_ACKVEC_LEN;
+
+       for (i = 0; i < nr_opts; ++i) {
+               int copylen = len;
+
+               if (len > DCCP_MAX_ACKVEC_OPT_LEN)
+                       copylen = DCCP_MAX_ACKVEC_OPT_LEN;
 
-       /* Check if buf_head wraps */
-       if ((int)av->dccpav_buf_head + len > DCCP_MAX_ACKVEC_LEN) {
-               const u32 tailsize = DCCP_MAX_ACKVEC_LEN - av->dccpav_buf_head;
+               *to++ = DCCPO_ACK_VECTOR_0;
+               *to++ = copylen + 2;
 
-               memcpy(to, from, tailsize);
-               to   += tailsize;
-               len  -= tailsize;
-               from = av->dccpav_buf;
+               /* Check if buf_head wraps */
+               if (from + copylen > tail) {
+                       const u16 tailsize = tail - from;
+
+                       memcpy(to, from, tailsize);
+                       to      += tailsize;
+                       len     -= tailsize;
+                       copylen -= tailsize;
+                       from    = av->dccpav_buf;
+               }
+
+               memcpy(to, from, copylen);
+               from += copylen;
+               to   += copylen;
+               len  -= copylen;
        }
 
-       memcpy(to, from, len);
        /*
-        *      From draft-ietf-dccp-spec-11.txt:
+        *      From RFC 4340, A.2:
         *
         *      For each acknowledgement it sends, the HC-Receiver will add an
         *      acknowledgement record.  ack_seqno will equal the HC-Receiver
@@ -129,9 +143,9 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 
        dccp_ackvec_insert_avr(av, avr);
 
-       dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
+       dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
                      "ack_ackno=%llu\n",
-                     debug_prefix, avr->dccpavr_sent_len,
+                     dccp_role(sk), avr->dccpavr_sent_len,
                      (unsigned long long)avr->dccpavr_ack_seqno,
                      (unsigned long long)avr->dccpavr_ack_ackno);
        return 0;
@@ -142,14 +156,12 @@ struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
        struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority);
 
        if (av != NULL) {
-               av->dccpav_buf_head     =
-                       av->dccpav_buf_tail = DCCP_MAX_ACKVEC_LEN - 1;
+               av->dccpav_buf_head     = 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;
+               av->dccpav_vec_len      = 0;
                INIT_LIST_HEAD(&av->dccpav_records);
        }
 
@@ -175,13 +187,13 @@ void dccp_ackvec_free(struct dccp_ackvec *av)
 }
 
 static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av,
-                                  const u8 index)
+                                  const u32 index)
 {
        return av->dccpav_buf[index] & DCCP_ACKVEC_STATE_MASK;
 }
 
 static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av,
-                                const u8 index)
+                                const u32 index)
 {
        return av->dccpav_buf[index] & DCCP_ACKVEC_LEN_MASK;
 }
@@ -211,7 +223,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
                        gap = -new_head;
                }
                new_head += DCCP_MAX_ACKVEC_LEN;
-       } 
+       }
 
        av->dccpav_buf_head = new_head;
 
@@ -225,7 +237,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
 }
 
 /*
- * Implements the draft-ietf-dccp-spec-11.txt Appendix A
+ * Implements the RFC 4340, Appendix A
  */
 int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
                    const u64 ackno, const u8 state)
@@ -238,7 +250,7 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
         * We may well decide to do buffer compression, etc, but for now lets
         * just drop.
         *
-        * From Appendix A:
+        * From Appendix A.1.1 (`New Packets'):
         *
         *      Of course, the circular buffer may overflow, either when the
         *      HC-Sender is sending data at a very high rate, when the
@@ -275,13 +287,13 @@ int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
                /*
                 * A.1.2.  Old Packets
                 *
-                *      When a packet with Sequence Number S arrives, and
-                *      S <= buf_ackno, the HC-Receiver will scan the table
-                *      for the byte corresponding to S. (Indexing structures
+                *      When a packet with Sequence Number S <= buf_ackno
+                *      arrives, the HC-Receiver will scan the table for
+                *      the byte corresponding to S. (Indexing structures
                 *      could reduce the complexity of this scan.)
                 */
                u64 delta = dccp_delta_seqno(ackno, av->dccpav_buf_ackno);
-               u8 index = av->dccpav_buf_head;
+               u32 index = av->dccpav_buf_head;
 
                while (1) {
                        const u8 len = dccp_ackvec_len(av, index);
@@ -323,21 +335,18 @@ out_duplicate:
 #ifdef CONFIG_IP_DCCP_DEBUG
 void dccp_ackvector_print(const u64 ackno, const unsigned char *vector, int len)
 {
-       if (!dccp_debug)
-               return;
-
-       printk("ACK vector len=%d, ackno=%llu |", len,
-              (unsigned long long)ackno);
+       dccp_pr_debug_cat("ACK vector len=%d, ackno=%llu |", len,
+                        (unsigned long long)ackno);
 
        while (len--) {
                const u8 state = (*vector & DCCP_ACKVEC_STATE_MASK) >> 6;
                const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
 
-               printk("%d,%d|", state, rl);
+               dccp_pr_debug_cat("%d,%d|", state, rl);
                ++vector;
        }
 
-       printk("\n");
+       dccp_pr_debug_cat("\n");
 }
 
 void dccp_ackvec_print(const struct dccp_ackvec *av)
@@ -353,11 +362,13 @@ static void dccp_ackvec_throw_record(struct dccp_ackvec *av,
 {
        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;
+       /* sort out vector length */
+       if (av->dccpav_buf_head <= avr->dccpavr_ack_ptr)
+               av->dccpav_vec_len = avr->dccpavr_ack_ptr - av->dccpav_buf_head;
+       else
+               av->dccpav_vec_len = DCCP_MAX_ACKVEC_LEN - 1
+                                    - av->dccpav_buf_head
+                                    + avr->dccpavr_ack_ptr;
 
        /* free records */
        list_for_each_entry_safe_from(avr, next, &av->dccpav_records,
@@ -379,24 +390,20 @@ void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
         */
        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: ";
-#endif
-                       dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
+                       dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, "
                                      "ack_ackno=%llu, ACKED!\n",
-                                     debug_prefix, 1,
+                                     dccp_role(sk), 1,
                                      (unsigned long long)avr->dccpavr_ack_seqno,
                                      (unsigned long long)avr->dccpavr_ack_ackno);
                        dccp_ackvec_throw_record(av, avr);
                        break;
-               }
+               } else if (avr->dccpavr_ack_seqno > ackno)
+                       break; /* old news */
        }
 }
 
 static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
-                                           struct sock *sk, u64 ackno,
+                                           struct sock *sk, u64 *ackno,
                                            const unsigned char len,
                                            const unsigned char *vector)
 {
@@ -419,7 +426,7 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
                const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
                u64 ackno_end_rl;
 
-               dccp_set_seqno(&ackno_end_rl, ackno - rl);
+               dccp_set_seqno(&ackno_end_rl, *ackno - rl);
 
                /*
                 * If our AVR sequence number is greater than the ack, go
@@ -427,26 +434,19 @@ static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
                 */
                list_for_each_entry_from(avr, &av->dccpav_records,
                                         dccpavr_node) {
-                       if (!after48(avr->dccpavr_ack_seqno, ackno))
+                       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;
+               if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, *ackno)) {
+                       const u8 state = *vector & DCCP_ACKVEC_STATE_MASK;
                        if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {
-#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: ";
-#endif
-                               dccp_pr_debug("%sACK vector 0, len=%d, "
+                               dccp_pr_debug("%s ACK vector 0, len=%d, "
                                              "ack_seqno=%llu, ack_ackno=%llu, "
                                              "ACKED!\n",
-                                             debug_prefix, len,
+                                             dccp_role(sk), len,
                                              (unsigned long long)
                                              avr->dccpavr_ack_seqno,
                                              (unsigned long long)
@@ -460,27 +460,23 @@ found:
                         */
                }
 
-               dccp_set_seqno(&ackno, ackno_end_rl - 1);
+               dccp_set_seqno(ackno, ackno_end_rl - 1);
                ++vector;
        }
 }
 
 int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
-                     const u8 opt, const u8 *value, const u8 len)
+                     u64 *ackno, const u8 opt, const u8 *value, const u8 len)
 {
-       if (len > DCCP_MAX_ACKVEC_LEN)
+       if (len > DCCP_MAX_ACKVEC_OPT_LEN)
                return -1;
 
        /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */
        dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk,
-                                       DCCP_SKB_CB(skb)->dccpd_ack_seq,
-                                       len, value);
+                                       ackno, 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",
@@ -502,7 +498,7 @@ out_destroy_slab:
        kmem_cache_destroy(dccp_ackvec_slab);
        dccp_ackvec_slab = NULL;
 out_err:
-       printk(dccp_ackvec_slab_msg);
+       DCCP_CRIT("Unable to create Ack Vector slab cache");
        return -ENOBUFS;
 }