[DCCP]: Move the ack vector code to net/dccp/ackvec.[ch]

Isolating it, that will be used when we introduce a CCID2 (TCP-Like)
implementation.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 433 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
index d4c4242d8dd7..c480c506a4a4 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -18,15 +18,10 @@
 #include <linux/kernel.h>
 #include <linux/skbuff.h>
 
+#include "ackvec.h"
 #include "ccid.h"
 #include "dccp.h"
 
-static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap,
-                                             struct sock *sk,
-                                             const u64 ackno,
-                                             const unsigned char len,
-                                             const unsigned char *vector);
-
 /* stores the default values for new connection. may be changed with sysctl */
 static const struct dccp_options dccpo_default_values = {
         .dccpo_sequence_window    = DCCPF_INITIAL_SEQUENCE_WINDOW,
@@ -113,25 +108,13 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                                       opt_recv->dccpor_ndp);
                         break;
                 case DCCPO_ACK_VECTOR_0:
-                        if (len > DCCP_MAX_ACK_VECTOR_LEN)
-                                goto out_invalid_option;
-
+                case DCCPO_ACK_VECTOR_1:
                         if (pkt_type == DCCP_PKT_DATA)
                                 continue;
 
-                        opt_recv->dccpor_ack_vector_len = len;
-                        opt_recv->dccpor_ack_vector_idx = value - options;
-
-                        dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n",
-                                      debug_prefix, len,
-                                      (unsigned long long)
-                                      DCCP_SKB_CB(skb)->dccpd_ack_seq);
-                        dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq,
-                                             value, len);
-                        dccp_ackpkts_check_rcv_ackvector(dp->dccps_hc_rx_ackpkts,
-                                                         sk,
-                                                 DCCP_SKB_CB(skb)->dccpd_ack_seq,
-                                                         len, value);
+                        if (dp->dccps_options.dccpo_send_ack_vector &&
+                            dccp_ackvec_parse(sk, skb, opt, value, len))
+                                goto out_invalid_option;
                         break;
                 case DCCPO_TIMESTAMP:
                         if (len != 4)
@@ -352,86 +335,6 @@ void dccp_insert_option_elapsed_time(struct sock *sk,
 
 EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
 
-static void dccp_insert_option_ack_vector(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 opt: " : "server TX opt: ";
-#endif
-        struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
-        int len = ap->dccpap_buf_vector_len + 2;
-        struct timeval now;
-        u32 elapsed_time;
-        unsigned char *to, *from;
-
-        dccp_timestamp(sk, &now);
-        elapsed_time = timeval_delta(&now, &ap->dccpap_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) {
-                LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to "
-                                         "insert ACK Vector!\n");
-                return;
-        }
-
-        /*
-         * 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 (ap->dccpap_ack_seqno != DCCP_MAX_SEQNO + 1)
-                return;
-
-        DCCP_SKB_CB(skb)->dccpd_opt_len += len;
-
-        to    = skb_push(skb, len);
-        *to++ = DCCPO_ACK_VECTOR_0;
-        *to++ = len;
-
-        len  = ap->dccpap_buf_vector_len;
-        from = ap->dccpap_buf + ap->dccpap_buf_head;
-
-        /* Check if buf_head wraps */
-        if (ap->dccpap_buf_head + len > ap->dccpap_buf_len) {
-                const unsigned int tailsize = (ap->dccpap_buf_len -
-                                               ap->dccpap_buf_head);
-
-                memcpy(to, from, tailsize);
-                to   += tailsize;
-                len  -= tailsize;
-                from = ap->dccpap_buf;
-        }
-
-        memcpy(to, from, len);
-        /*
-         *      From draft-ietf-dccp-spec-11.txt:
-         *
-         *      For each acknowledgement it sends, the HC-Receiver will add an
-         *      acknowledgement record.  ack_seqno will equal the HC-Receiver
-         *      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.
-         */
-        ap->dccpap_ack_seqno      = DCCP_SKB_CB(skb)->dccpd_seq;
-        ap->dccpap_ack_ptr        = ap->dccpap_buf_head;
-        ap->dccpap_ack_ackno      = ap->dccpap_buf_ackno;
-        ap->dccpap_ack_nonce      = ap->dccpap_buf_nonce;
-        ap->dccpap_ack_vector_len = ap->dccpap_buf_vector_len;
-
-        dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
-                      "ack_ackno=%llu\n",
-                      debug_prefix, ap->dccpap_ack_vector_len,
-                      (unsigned long long) ap->dccpap_ack_seqno,
-                      (unsigned long long) ap->dccpap_ack_ackno);
-}
-
 void dccp_timestamp(const struct sock *sk, struct timeval *tv)
 {
         const struct dccp_sock *dp = dccp_sk(sk);
@@ -528,9 +431,8 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
 
         if (!dccp_packet_without_ack(skb)) {
                 if (dp->dccps_options.dccpo_send_ack_vector &&
-                    (dp->dccps_hc_rx_ackpkts->dccpap_buf_ackno !=
-                     DCCP_MAX_SEQNO + 1))
-                        dccp_insert_option_ack_vector(sk, skb);
+                    dccp_ackvec_pending(dp->dccps_hc_rx_ackvec))
+                        dccp_insert_option_ackvec(sk, skb);
                 if (dp->dccps_timestamp_echo != 0)
                         dccp_insert_option_timestamp_echo(sk, skb);
         }
@@ -557,331 +459,3 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
                 }
         }
 }
-
-struct dccp_ackpkts *dccp_ackpkts_alloc(const unsigned int len,
-                                        const unsigned int __nocast priority)
-{
-        struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority);
-
-        if (ap != NULL) {
-#ifdef CONFIG_IP_DCCP_DEBUG
-                memset(ap->dccpap_buf, 0xFF, len);
-#endif
-                ap->dccpap_buf_len   = len;
-                ap->dccpap_buf_head  =
-                        ap->dccpap_buf_tail =
-                                ap->dccpap_buf_len - 1;
-                ap->dccpap_buf_ackno =
-                        ap->dccpap_ack_ackno =
-                                ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
-                ap->dccpap_buf_nonce = ap->dccpap_buf_nonce = 0;
-                ap->dccpap_ack_ptr   = 0;
-                ap->dccpap_time.tv_sec = 0;
-                ap->dccpap_time.tv_usec = 0;
-                ap->dccpap_buf_vector_len = ap->dccpap_ack_vector_len = 0;
-        }
-
-        return ap;
-}
-
-void dccp_ackpkts_free(struct dccp_ackpkts *ap)
-{
-        if (ap != NULL) {
-#ifdef CONFIG_IP_DCCP_DEBUG
-                memset(ap, 0xFF, sizeof(*ap) + ap->dccpap_buf_len);
-#endif
-                kfree(ap);
-        }
-}
-
-static inline u8 dccp_ackpkts_state(const struct dccp_ackpkts *ap,
-                                    const unsigned int index)
-{
-        return ap->dccpap_buf[index] & DCCP_ACKPKTS_STATE_MASK;
-}
-
-static inline u8 dccp_ackpkts_len(const struct dccp_ackpkts *ap,
-                                  const unsigned int index)
-{
-        return ap->dccpap_buf[index] & DCCP_ACKPKTS_LEN_MASK;
-}
-
-/*
- * If several packets are missing, the HC-Receiver may prefer to enter multiple
- * bytes with run length 0, rather than a single byte with a larger run length;
- * this simplifies table updates if one of the missing packets arrives.
- */
-static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap,
-                                                  const unsigned int packets,
-                                                  const unsigned char state)
-{
-        unsigned int gap;
-        signed long new_head;
-
-        if (ap->dccpap_buf_vector_len + packets > ap->dccpap_buf_len)
-                return -ENOBUFS;
-
-        gap      = packets - 1;
-        new_head = ap->dccpap_buf_head - packets;
-
-        if (new_head < 0) {
-                if (gap > 0) {
-                        memset(ap->dccpap_buf, DCCP_ACKPKTS_STATE_NOT_RECEIVED,
-                               gap + new_head + 1);
-                        gap = -new_head;
-                }
-                new_head += ap->dccpap_buf_len;
-        } 
-
-        ap->dccpap_buf_head = new_head;
-
-        if (gap > 0)
-                memset(ap->dccpap_buf + ap->dccpap_buf_head + 1,
-                       DCCP_ACKPKTS_STATE_NOT_RECEIVED, gap);
-
-        ap->dccpap_buf[ap->dccpap_buf_head] = state;
-        ap->dccpap_buf_vector_len += packets;
-        return 0;
-}
-
-/*
- * Implements the draft-ietf-dccp-spec-11.txt Appendix A
- */
-int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
-                     u64 ackno, u8 state)
-{
-        /*
-         * Check at the right places if the buffer is full, if it is, tell the
-         * caller to start dropping packets till the HC-Sender acks our ACK
-         * vectors, when we will free up space in dccpap_buf.
-         *
-         * We may well decide to do buffer compression, etc, but for now lets
-         * just drop.
-         *
-         * From Appendix A:
-         *
-         *      Of course, the circular buffer may overflow, either when the
-         *      HC-Sender is sending data at a very high rate, when the
-         *      HC-Receiver's acknowledgements are not reaching the HC-Sender,
-         *      or when the HC-Sender is forgetting to acknowledge those acks
-         *      (so the HC-Receiver is unable to clean up old state). In this
-         *      case, the HC-Receiver should either compress the buffer (by
-         *      increasing run lengths when possible), transfer its state to
-         *      a larger buffer, or, as a last resort, drop all received
-         *      packets, without processing them whatsoever, until its buffer
-         *      shrinks again.
-         */
-
-        /* See if this is the first ackno being inserted */
-        if (ap->dccpap_buf_vector_len == 0) {
-                ap->dccpap_buf[ap->dccpap_buf_head] = state;
-                ap->dccpap_buf_vector_len = 1;
-        } else if (after48(ackno, ap->dccpap_buf_ackno)) {
-                const u64 delta = dccp_delta_seqno(ap->dccpap_buf_ackno,
-                                                   ackno);
-
-                /*
-                 * Look if the state of this packet is the same as the
-                 * previous ackno and if so if we can bump the head len.
-                 */
-                if (delta == 1 &&
-                    dccp_ackpkts_state(ap, ap->dccpap_buf_head) == state &&
-                    (dccp_ackpkts_len(ap, ap->dccpap_buf_head) <
-                     DCCP_ACKPKTS_LEN_MASK))
-                        ap->dccpap_buf[ap->dccpap_buf_head]++;
-                else if (dccp_ackpkts_set_buf_head_state(ap, delta, state))
-                        return -ENOBUFS;
-        } else {
-                /*
-                 * 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
-                 *      could reduce the complexity of this scan.)
-                 */
-                u64 delta = dccp_delta_seqno(ackno, ap->dccpap_buf_ackno);
-                unsigned int index = ap->dccpap_buf_head;
-
-                while (1) {
-                        const u8 len = dccp_ackpkts_len(ap, index);
-                        const u8 state = dccp_ackpkts_state(ap, index);
-                        /*
-                         * valid packets not yet in dccpap_buf have a reserved
-                         * entry, with a len equal to 0.
-                         */
-                        if (state == DCCP_ACKPKTS_STATE_NOT_RECEIVED &&
-                            len == 0 && delta == 0) { /* Found our
-                                                         reserved seat! */
-                                dccp_pr_debug("Found %llu reserved seat!\n",
-                                              (unsigned long long) ackno);
-                                ap->dccpap_buf[index] = state;
-                                goto out;
-                        }
-                        /* len == 0 means one packet */
-                        if (delta < len + 1)
-                                goto out_duplicate;
-
-                        delta -= len + 1;
-                        if (++index == ap->dccpap_buf_len)
-                                index = 0;
-                }
-        }
-
-        ap->dccpap_buf_ackno = ackno;
-        dccp_timestamp(sk, &ap->dccpap_time);
-out:
-        dccp_pr_debug("");
-        dccp_ackpkts_print(ap);
-        return 0;
-
-out_duplicate:
-        /* Duplicate packet */
-        dccp_pr_debug("Received a dup or already considered lost "
-                      "packet: %llu\n", (unsigned long long) ackno);
-        return -EILSEQ;
-}
-
-#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);
-
-        while (len--) {
-                const u8 state = (*vector & DCCP_ACKPKTS_STATE_MASK) >> 6;
-                const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK);
-
-                printk("%d,%d|", state, rl);
-                ++vector;
-        }
-
-        printk("\n");
-}
-
-void dccp_ackpkts_print(const struct dccp_ackpkts *ap)
-{
-        dccp_ackvector_print(ap->dccpap_buf_ackno,
-                             ap->dccpap_buf + ap->dccpap_buf_head,
-                             ap->dccpap_buf_vector_len);
-}
-#endif
-
-static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts *ap)
-{
-        /*
-         * As we're keeping track of the ack vector size
-         * (dccpap_buf_vector_len) and the sent ack vector size
-         * (dccpap_ack_vector_len) we don't need dccpap_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
-        ap->dccpap_buf_tail = ap->dccpap_ack_ptr + 1;
-        if (ap->dccpap_buf_tail >= ap->dccpap_buf_len)
-                ap->dccpap_buf_tail -= ap->dccpap_buf_len;
-#endif
-        ap->dccpap_buf_vector_len -= ap->dccpap_ack_vector_len;
-}
-
-void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap, struct sock *sk,
-                                 u64 ackno)
-{
-        /* Check if we actually sent an ACK vector */
-        if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1)
-                return;
-
-        if (ackno == ap->dccpap_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, "
-                              "ack_ackno=%llu, ACKED!\n",
-                              debug_prefix, 1,
-                              (unsigned long long) ap->dccpap_ack_seqno,
-                              (unsigned long long) ap->dccpap_ack_ackno);
-                dccp_ackpkts_trow_away_ack_record(ap);
-                ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
-        }
-}
-
-static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap,
-                                             struct sock *sk, u64 ackno,
-                                             const unsigned char len,
-                                             const unsigned char *vector)
-{
-        unsigned char i;
-
-        /* Check if we actually sent an ACK vector */
-        if (ap->dccpap_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 dccpap_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, ap->dccpap_ack_seqno); */
-        if (before48(ackno, ap->dccpap_ack_seqno)) {
-                /* dccp_pr_debug_cat("yes\n"); */
-                return;
-        }
-        /* dccp_pr_debug_cat("no\n"); */
-
-        i = len;
-        while (i--) {
-                const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK);
-                u64 ackno_end_rl;
-
-                dccp_set_seqno(&ackno_end_rl, ackno - rl);
-
-                /*
-                 * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl,
-                 * ap->dccpap_ack_seqno, ackno);
-                 */
-                if (between48(ap->dccpap_ack_seqno, ackno_end_rl, ackno)) {
-                        const u8 state = (*vector &
-                                          DCCP_ACKPKTS_STATE_MASK) >> 6;
-                        /* dccp_pr_debug_cat("yes\n"); */
-
-                        if (state != DCCP_ACKPKTS_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, "
-                                              "ack_seqno=%llu, ack_ackno=%llu, "
-                                              "ACKED!\n",
-                                              debug_prefix, len,
-                                              (unsigned long long)
-                                              ap->dccpap_ack_seqno,
-                                              (unsigned long long)
-                                              ap->dccpap_ack_ackno);
-                                dccp_ackpkts_trow_away_ack_record(ap);
-                        }
-                        /*
-                         * If dccpap_ack_seqno was not received, no problem
-                         * we'll send another ACK vector.
-                         */
-                        ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1;
-                        break;
-                }
-                /* dccp_pr_debug_cat("no\n"); */
-
-                dccp_set_seqno(&ackno, ackno_end_rl - 1);
-                ++vector;
-        }
-}