dccp ccid-2: Remove old infrastructure
authorGerrit Renker <gerrit@erg.abdn.ac.uk>
Sun, 14 Nov 2010 16:26:02 +0000 (17:26 +0100)
committerGerrit Renker <gerrit@erg.abdn.ac.uk>
Mon, 15 Nov 2010 06:12:00 +0000 (07:12 +0100)
This removes
 * functions for which updates have been provided in the preceding patches and
 * the @av_vec_len field - it is no longer necessary since the buffer length is
   now always computed dynamically.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
net/dccp/ackvec.c
net/dccp/ackvec.h

index f7e647e608bbfe672abad27d9dd7327e65b179a0..66b8a51300c0cd3c18be3b340a38abfacfd71b0b 100644 (file)
@@ -9,18 +9,10 @@
  *      under the terms of the GNU General Public License as published by the
  *      Free Software Foundation; version 2 of the License;
  */
-
-#include "ackvec.h"
 #include "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 struct kmem_cache *dccp_ackvec_slab;
 static struct kmem_cache *dccp_ackvec_record_slab;
 
@@ -281,249 +273,6 @@ void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb)
        }
 }
 
-/*
- * 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_ackvec_set_buf_head_state(struct dccp_ackvec *av,
-                                                const unsigned int packets,
-                                                const unsigned char state)
-{
-       long gap;
-       long new_head;
-
-       if (av->av_vec_len + packets > DCCPAV_MAX_ACKVEC_LEN)
-               return -ENOBUFS;
-
-       gap      = packets - 1;
-       new_head = av->av_buf_head - packets;
-
-       if (new_head < 0) {
-               if (gap > 0) {
-                       memset(av->av_buf, DCCPAV_NOT_RECEIVED,
-                              gap + new_head + 1);
-                       gap = -new_head;
-               }
-               new_head += DCCPAV_MAX_ACKVEC_LEN;
-       }
-
-       av->av_buf_head = new_head;
-
-       if (gap > 0)
-               memset(av->av_buf + av->av_buf_head + 1,
-                      DCCPAV_NOT_RECEIVED, gap);
-
-       av->av_buf[av->av_buf_head] = state;
-       av->av_vec_len += packets;
-       return 0;
-}
-
-/*
- * Implements the RFC 4340, Appendix A
- */
-int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
-                   const u64 ackno, const u8 state)
-{
-       u8 *cur_head = av->av_buf + av->av_buf_head,
-          *buf_end  = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
-       /*
-        * 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 av_buf.
-        *
-        * We may well decide to do buffer compression, etc, but for now lets
-        * just drop.
-        *
-        * 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
-        *      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 (av->av_vec_len == 0) {
-               *cur_head = state;
-               av->av_vec_len = 1;
-       } else if (after48(ackno, av->av_buf_ackno)) {
-               const u64 delta = dccp_delta_seqno(av->av_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_ackvec_state(cur_head) == state &&
-                   dccp_ackvec_runlen(cur_head) < DCCPAV_MAX_RUNLEN)
-                       *cur_head += 1;
-               else if (dccp_ackvec_set_buf_head_state(av, delta, state))
-                       return -ENOBUFS;
-       } else {
-               /*
-                * A.1.2.  Old Packets
-                *
-                *      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->av_buf_ackno);
-
-               while (1) {
-                       const u8 len = dccp_ackvec_runlen(cur_head);
-                       /*
-                        * valid packets not yet in av_buf have a reserved
-                        * entry, with a len equal to 0.
-                        */
-                       if (*cur_head == DCCPAV_NOT_RECEIVED && delta == 0) {
-                               dccp_pr_debug("Found %llu reserved seat!\n",
-                                             (unsigned long long)ackno);
-                               *cur_head = state;
-                               goto out;
-                       }
-                       /* len == 0 means one packet */
-                       if (delta < len + 1)
-                               goto out_duplicate;
-
-                       delta -= len + 1;
-                       if (++cur_head == buf_end)
-                               cur_head = av->av_buf;
-               }
-       }
-
-       av->av_buf_ackno = ackno;
-out:
-       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;
-}
-
-static void dccp_ackvec_throw_record(struct dccp_ackvec *av,
-                                    struct dccp_ackvec_record *avr)
-{
-       struct dccp_ackvec_record *next;
-
-       /* sort out vector length */
-       if (av->av_buf_head <= avr->avr_ack_ptr)
-               av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head;
-       else
-               av->av_vec_len = DCCPAV_MAX_ACKVEC_LEN - 1 -
-                                av->av_buf_head + avr->avr_ack_ptr;
-
-       /* free records */
-       list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) {
-               list_del(&avr->avr_node);
-               kmem_cache_free(dccp_ackvec_record_slab, avr);
-       }
-}
-
-void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
-                                const u64 ackno)
-{
-       struct dccp_ackvec_record *avr;
-
-       /*
-        * 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->av_records, avr_node) {
-               if (ackno == avr->avr_ack_seqno) {
-                       dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, "
-                                     "ack_ackno=%llu, ACKED!\n",
-                                     dccp_role(sk), avr->avr_ack_runlen,
-                                     (unsigned long long)avr->avr_ack_seqno,
-                                     (unsigned long long)avr->avr_ack_ackno);
-                       dccp_ackvec_throw_record(av, avr);
-                       break;
-               } else if (avr->avr_ack_seqno > ackno)
-                       break; /* old news */
-       }
-}
-
-static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
-                                           struct sock *sk, u64 *ackno,
-                                           const unsigned char len,
-                                           const unsigned char *vector)
-{
-       unsigned char i;
-       struct dccp_ackvec_record *avr;
-
-       /* Check if we actually sent an ACK vector */
-       if (list_empty(&av->av_records))
-               return;
-
-       i = len;
-       /*
-        * XXX
-        * I think it might be more efficient to work backwards. See comment on
-        * rcv_ackno. -sorbo.
-        */
-       avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node);
-       while (i--) {
-               const u8 rl = dccp_ackvec_runlen(vector);
-               u64 ackno_end_rl;
-
-               dccp_set_seqno(&ackno_end_rl, *ackno - rl);
-
-               /*
-                * If our AVR sequence number is greater than the ack, go
-                * forward in the AVR list until it is not so.
-                */
-               list_for_each_entry_from(avr, &av->av_records, avr_node) {
-                       if (!after48(avr->avr_ack_seqno, *ackno))
-                               goto found;
-               }
-               /* End of the av_records list, not found, exit */
-               break;
-found:
-               if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) {
-                       if (dccp_ackvec_state(vector) != DCCPAV_NOT_RECEIVED) {
-                               dccp_pr_debug("%s ACK vector 0, len=%d, "
-                                             "ack_seqno=%llu, ack_ackno=%llu, "
-                                             "ACKED!\n",
-                                             dccp_role(sk), len,
-                                             (unsigned long long)
-                                             avr->avr_ack_seqno,
-                                             (unsigned long long)
-                                             avr->avr_ack_ackno);
-                               dccp_ackvec_throw_record(av, avr);
-                               break;
-                       }
-                       /*
-                        * If it wasn't received, continue scanning... we might
-                        * find another one.
-                        */
-               }
-
-               dccp_set_seqno(ackno, ackno_end_rl - 1);
-               ++vector;
-       }
-}
-
-int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
-                     u64 *ackno, const u8 opt, const u8 *value, const u8 len)
-{
-       if (len > DCCP_SINGLE_OPT_MAXLEN)
-               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,
-                                       ackno, len, value);
-       return 0;
-}
-
 /**
  * dccp_ackvec_clear_state  -  Perform house-keeping / garbage-collection
  * This routine is called when the peer acknowledges the receipt of Ack Vectors
index 21c4212d1be0c89a298a0b728107b19893d309f5..e19b8d5ee05f761b6c8f88af273e915b481cc2af 100644 (file)
@@ -64,7 +64,6 @@ static inline u8 dccp_ackvec_state(const u8 *cell)
  *                %DCCP_SINGLE_OPT_MAXLEN cells in the live portion of @av_buf
  * @av_overflow:   if 1 then buf_head == buf_tail indicates buffer wraparound
  * @av_records:           list of %dccp_ackvec_record (Ack Vectors sent previously)
- * @av_veclen:    length of the live portion of @av_buf
  */
 struct dccp_ackvec {
        u8                      av_buf[DCCPAV_MAX_ACKVEC_LEN];
@@ -75,7 +74,6 @@ struct dccp_ackvec {
        bool                    av_buf_nonce[DCCPAV_NUM_ACKVECS];
        u8                      av_overflow:1;
        struct list_head        av_records;
-       u16                     av_vec_len;
 };
 
 /** struct dccp_ackvec_record - Records information about sent Ack Vectors
@@ -101,24 +99,12 @@ struct dccp_ackvec_record {
        u8               avr_ack_nonce:1;
 };
 
-struct sock;
-struct sk_buff;
-
 extern int dccp_ackvec_init(void);
 extern void dccp_ackvec_exit(void);
 
 extern struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority);
 extern void dccp_ackvec_free(struct dccp_ackvec *av);
 
-extern int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
-                          const u64 ackno, const u8 state);
-
-extern void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av,
-                                       struct sock *sk, const u64 ackno);
-extern int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
-                            u64 *ackno, const u8 opt,
-                            const u8 *value, const u8 len);
-
 extern void dccp_ackvec_input(struct dccp_ackvec *av, struct sk_buff *skb);
 extern int  dccp_ackvec_update_records(struct dccp_ackvec *av, u64 seq, u8 sum);
 extern void dccp_ackvec_clear_state(struct dccp_ackvec *av, const u64 ackno);