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Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -07001/*
2 * net/dccp/ackvec.c
3 *
4 * An implementation of the DCCP protocol
5 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; version 2 of the License;
10 */
11
12#include "ackvec.h"
13#include "dccp.h"
14
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080015#include <linux/init.h>
16#include <linux/errno.h>
17#include <linux/kernel.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070018#include <linux/skbuff.h>
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080019#include <linux/slab.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070020
21#include <net/sock.h>
22
Christoph Lametere18b8902006-12-06 20:33:20 -080023static struct kmem_cache *dccp_ackvec_slab;
24static struct kmem_cache *dccp_ackvec_record_slab;
Andrea Bittau02bcf282006-03-20 17:19:55 -080025
26static struct dccp_ackvec_record *dccp_ackvec_record_new(void)
27{
28 struct dccp_ackvec_record *avr =
29 kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
30
31 if (avr != NULL)
Gerrit Renkera47c5102007-12-30 04:19:31 -080032 INIT_LIST_HEAD(&avr->avr_node);
Andrea Bittau02bcf282006-03-20 17:19:55 -080033
34 return avr;
35}
36
37static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr)
38{
39 if (unlikely(avr == NULL))
40 return;
41 /* Check if deleting a linked record */
Gerrit Renkera47c5102007-12-30 04:19:31 -080042 WARN_ON(!list_empty(&avr->avr_node));
Andrea Bittau02bcf282006-03-20 17:19:55 -080043 kmem_cache_free(dccp_ackvec_record_slab, avr);
44}
45
46static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
47 struct dccp_ackvec_record *avr)
48{
49 /*
50 * AVRs are sorted by seqno. Since we are sending them in order, we
51 * just add the AVR at the head of the list.
52 * -sorbo.
53 */
Gerrit Renkera47c5102007-12-30 04:19:31 -080054 if (!list_empty(&av->av_records)) {
Andrea Bittau02bcf282006-03-20 17:19:55 -080055 const struct dccp_ackvec_record *head =
Gerrit Renkera47c5102007-12-30 04:19:31 -080056 list_entry(av->av_records.next,
Andrea Bittau02bcf282006-03-20 17:19:55 -080057 struct dccp_ackvec_record,
Gerrit Renkera47c5102007-12-30 04:19:31 -080058 avr_node);
59 BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno));
Andrea Bittau02bcf282006-03-20 17:19:55 -080060 }
61
Gerrit Renkera47c5102007-12-30 04:19:31 -080062 list_add(&avr->avr_node, &av->av_records);
Andrea Bittau02bcf282006-03-20 17:19:55 -080063}
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080064
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070065int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
66{
67 struct dccp_sock *dp = dccp_sk(sk);
68 struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
Andrea Bittau522f1d02006-11-26 01:04:40 -020069 /* Figure out how many options do we need to represent the ackvec */
Gerrit Renkerb20a9c22008-11-23 16:02:31 -080070 const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
Gerrit Renkera47c5102007-12-30 04:19:31 -080071 u16 len = av->av_vec_len + 2 * nr_opts, i;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070072 u32 elapsed_time;
Andrea Bittau522f1d02006-11-26 01:04:40 -020073 const unsigned char *tail, *from;
74 unsigned char *to;
Andrea Bittau02bcf282006-03-20 17:19:55 -080075 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070076 suseconds_t delta;
Andrea Bittau02bcf282006-03-20 17:19:55 -080077
78 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
79 return -1;
80
Gerrit Renkera47c5102007-12-30 04:19:31 -080081 delta = ktime_us_delta(ktime_get_real(), av->av_time);
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070082 elapsed_time = delta / 10;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070083
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -080084 if (elapsed_time != 0 &&
85 dccp_insert_option_elapsed_time(sk, skb, elapsed_time))
86 return -1;
87
88 avr = dccp_ackvec_record_new();
89 if (avr == NULL)
90 return -1;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070091
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070092 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
93
Andrea Bittau522f1d02006-11-26 01:04:40 -020094 to = skb_push(skb, len);
Gerrit Renkera47c5102007-12-30 04:19:31 -080095 len = av->av_vec_len;
96 from = av->av_buf + av->av_buf_head;
97 tail = av->av_buf + DCCP_MAX_ACKVEC_LEN;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070098
Andrea Bittau522f1d02006-11-26 01:04:40 -020099 for (i = 0; i < nr_opts; ++i) {
100 int copylen = len;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700101
Gerrit Renkerb20a9c22008-11-23 16:02:31 -0800102 if (len > DCCP_SINGLE_OPT_MAXLEN)
103 copylen = DCCP_SINGLE_OPT_MAXLEN;
Andrea Bittau522f1d02006-11-26 01:04:40 -0200104
105 *to++ = DCCPO_ACK_VECTOR_0;
106 *to++ = copylen + 2;
107
108 /* Check if buf_head wraps */
109 if (from + copylen > tail) {
110 const u16 tailsize = tail - from;
111
112 memcpy(to, from, tailsize);
113 to += tailsize;
114 len -= tailsize;
115 copylen -= tailsize;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800116 from = av->av_buf;
Andrea Bittau522f1d02006-11-26 01:04:40 -0200117 }
118
119 memcpy(to, from, copylen);
120 from += copylen;
121 to += copylen;
122 len -= copylen;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700123 }
124
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700125 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700126 * From RFC 4340, A.2:
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700127 *
128 * For each acknowledgement it sends, the HC-Receiver will add an
129 * acknowledgement record. ack_seqno will equal the HC-Receiver
130 * sequence number it used for the ack packet; ack_ptr will equal
131 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will
132 * equal buf_nonce.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700133 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800134 avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
135 avr->avr_ack_ptr = av->av_buf_head;
136 avr->avr_ack_ackno = av->av_buf_ackno;
137 avr->avr_ack_nonce = av->av_buf_nonce;
138 avr->avr_sent_len = av->av_vec_len;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800139
140 dccp_ackvec_insert_avr(av, avr);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700141
Gerrit Renker09dbc382006-11-14 12:57:34 -0200142 dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700143 "ack_ackno=%llu\n",
Gerrit Renkera47c5102007-12-30 04:19:31 -0800144 dccp_role(sk), avr->avr_sent_len,
145 (unsigned long long)avr->avr_ack_seqno,
146 (unsigned long long)avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800147 return 0;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700148}
149
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800150struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700151{
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800152 struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700153
154 if (av != NULL) {
Gerrit Renkera47c5102007-12-30 04:19:31 -0800155 av->av_buf_head = DCCP_MAX_ACKVEC_LEN - 1;
156 av->av_buf_ackno = UINT48_MAX + 1;
157 av->av_buf_nonce = 0;
158 av->av_time = ktime_set(0, 0);
159 av->av_vec_len = 0;
160 INIT_LIST_HEAD(&av->av_records);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700161 }
162
163 return av;
164}
165
166void dccp_ackvec_free(struct dccp_ackvec *av)
167{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800168 if (unlikely(av == NULL))
169 return;
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800170
Gerrit Renkera47c5102007-12-30 04:19:31 -0800171 if (!list_empty(&av->av_records)) {
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800172 struct dccp_ackvec_record *avr, *next;
173
Gerrit Renkera47c5102007-12-30 04:19:31 -0800174 list_for_each_entry_safe(avr, next, &av->av_records, avr_node) {
175 list_del_init(&avr->avr_node);
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800176 dccp_ackvec_record_delete(avr);
177 }
178 }
179
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800180 kmem_cache_free(dccp_ackvec_slab, av);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700181}
182
183static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200184 const u32 index)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700185{
Gerrit Renkera47c5102007-12-30 04:19:31 -0800186 return av->av_buf[index] & DCCP_ACKVEC_STATE_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700187}
188
189static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200190 const u32 index)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700191{
Gerrit Renkera47c5102007-12-30 04:19:31 -0800192 return av->av_buf[index] & DCCP_ACKVEC_LEN_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700193}
194
195/*
196 * If several packets are missing, the HC-Receiver may prefer to enter multiple
197 * bytes with run length 0, rather than a single byte with a larger run length;
198 * this simplifies table updates if one of the missing packets arrives.
199 */
200static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
201 const unsigned int packets,
Arnaldo Carvalho de Meloe4dfd4492006-01-04 01:46:34 -0200202 const unsigned char state)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700203{
204 unsigned int gap;
Kris Katterjohna8fc3d82006-01-17 13:03:54 -0800205 long new_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700206
Gerrit Renkera47c5102007-12-30 04:19:31 -0800207 if (av->av_vec_len + packets > DCCP_MAX_ACKVEC_LEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700208 return -ENOBUFS;
209
210 gap = packets - 1;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800211 new_head = av->av_buf_head - packets;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700212
213 if (new_head < 0) {
214 if (gap > 0) {
Gerrit Renkera47c5102007-12-30 04:19:31 -0800215 memset(av->av_buf, DCCP_ACKVEC_STATE_NOT_RECEIVED,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700216 gap + new_head + 1);
217 gap = -new_head;
218 }
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800219 new_head += DCCP_MAX_ACKVEC_LEN;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200220 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700221
Gerrit Renkera47c5102007-12-30 04:19:31 -0800222 av->av_buf_head = new_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700223
224 if (gap > 0)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800225 memset(av->av_buf + av->av_buf_head + 1,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700226 DCCP_ACKVEC_STATE_NOT_RECEIVED, gap);
227
Gerrit Renkera47c5102007-12-30 04:19:31 -0800228 av->av_buf[av->av_buf_head] = state;
229 av->av_vec_len += packets;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700230 return 0;
231}
232
233/*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700234 * Implements the RFC 4340, Appendix A
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700235 */
236int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
237 const u64 ackno, const u8 state)
238{
239 /*
240 * Check at the right places if the buffer is full, if it is, tell the
241 * caller to start dropping packets till the HC-Sender acks our ACK
Gerrit Renkera47c5102007-12-30 04:19:31 -0800242 * vectors, when we will free up space in av_buf.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700243 *
244 * We may well decide to do buffer compression, etc, but for now lets
245 * just drop.
246 *
Gerrit Renker0e64e942006-10-24 16:17:51 -0700247 * From Appendix A.1.1 (`New Packets'):
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700248 *
249 * Of course, the circular buffer may overflow, either when the
250 * HC-Sender is sending data at a very high rate, when the
251 * HC-Receiver's acknowledgements are not reaching the HC-Sender,
252 * or when the HC-Sender is forgetting to acknowledge those acks
253 * (so the HC-Receiver is unable to clean up old state). In this
254 * case, the HC-Receiver should either compress the buffer (by
255 * increasing run lengths when possible), transfer its state to
256 * a larger buffer, or, as a last resort, drop all received
257 * packets, without processing them whatsoever, until its buffer
258 * shrinks again.
259 */
260
261 /* See if this is the first ackno being inserted */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800262 if (av->av_vec_len == 0) {
263 av->av_buf[av->av_buf_head] = state;
264 av->av_vec_len = 1;
265 } else if (after48(ackno, av->av_buf_ackno)) {
266 const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700267
268 /*
269 * Look if the state of this packet is the same as the
270 * previous ackno and if so if we can bump the head len.
271 */
272 if (delta == 1 &&
Gerrit Renkera47c5102007-12-30 04:19:31 -0800273 dccp_ackvec_state(av, av->av_buf_head) == state &&
274 dccp_ackvec_len(av, av->av_buf_head) < DCCP_ACKVEC_LEN_MASK)
275 av->av_buf[av->av_buf_head]++;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700276 else if (dccp_ackvec_set_buf_head_state(av, delta, state))
277 return -ENOBUFS;
278 } else {
279 /*
280 * A.1.2. Old Packets
281 *
Gerrit Renker0e64e942006-10-24 16:17:51 -0700282 * When a packet with Sequence Number S <= buf_ackno
283 * arrives, the HC-Receiver will scan the table for
284 * the byte corresponding to S. (Indexing structures
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700285 * could reduce the complexity of this scan.)
286 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800287 u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno);
288 u32 index = av->av_buf_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700289
290 while (1) {
291 const u8 len = dccp_ackvec_len(av, index);
Gerrit Renker1e2f0e52008-06-11 11:19:09 +0100292 const u8 av_state = dccp_ackvec_state(av, index);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700293 /*
Gerrit Renkera47c5102007-12-30 04:19:31 -0800294 * valid packets not yet in av_buf have a reserved
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700295 * entry, with a len equal to 0.
296 */
Gerrit Renker1e2f0e52008-06-11 11:19:09 +0100297 if (av_state == DCCP_ACKVEC_STATE_NOT_RECEIVED &&
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700298 len == 0 && delta == 0) { /* Found our
299 reserved seat! */
300 dccp_pr_debug("Found %llu reserved seat!\n",
301 (unsigned long long)ackno);
Gerrit Renkera47c5102007-12-30 04:19:31 -0800302 av->av_buf[index] = state;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700303 goto out;
304 }
305 /* len == 0 means one packet */
306 if (delta < len + 1)
307 goto out_duplicate;
308
309 delta -= len + 1;
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800310 if (++index == DCCP_MAX_ACKVEC_LEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700311 index = 0;
312 }
313 }
314
Gerrit Renkera47c5102007-12-30 04:19:31 -0800315 av->av_buf_ackno = ackno;
316 av->av_time = ktime_get_real();
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700317out:
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700318 return 0;
319
320out_duplicate:
321 /* Duplicate packet */
322 dccp_pr_debug("Received a dup or already considered lost "
323 "packet: %llu\n", (unsigned long long)ackno);
324 return -EILSEQ;
325}
326
Andrea Bittau02bcf282006-03-20 17:19:55 -0800327static void dccp_ackvec_throw_record(struct dccp_ackvec *av,
328 struct dccp_ackvec_record *avr)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700329{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800330 struct dccp_ackvec_record *next;
331
Andrea Bittau23d06e32006-09-19 13:04:54 -0700332 /* sort out vector length */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800333 if (av->av_buf_head <= avr->avr_ack_ptr)
334 av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head;
Andrea Bittau23d06e32006-09-19 13:04:54 -0700335 else
Gerrit Renkera47c5102007-12-30 04:19:31 -0800336 av->av_vec_len = DCCP_MAX_ACKVEC_LEN - 1 -
337 av->av_buf_head + avr->avr_ack_ptr;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800338
339 /* free records */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800340 list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) {
341 list_del_init(&avr->avr_node);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800342 dccp_ackvec_record_delete(avr);
343 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700344}
345
346void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
347 const u64 ackno)
348{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800349 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700350
Andrea Bittau02bcf282006-03-20 17:19:55 -0800351 /*
352 * If we traverse backwards, it should be faster when we have large
353 * windows. We will be receiving ACKs for stuff we sent a while back
354 * -sorbo.
355 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800356 list_for_each_entry_reverse(avr, &av->av_records, avr_node) {
357 if (ackno == avr->avr_ack_seqno) {
Gerrit Renker09dbc382006-11-14 12:57:34 -0200358 dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, "
Andrea Bittau02bcf282006-03-20 17:19:55 -0800359 "ack_ackno=%llu, ACKED!\n",
Gerrit Renker09dbc382006-11-14 12:57:34 -0200360 dccp_role(sk), 1,
Gerrit Renkera47c5102007-12-30 04:19:31 -0800361 (unsigned long long)avr->avr_ack_seqno,
362 (unsigned long long)avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800363 dccp_ackvec_throw_record(av, avr);
364 break;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800365 } else if (avr->avr_ack_seqno > ackno)
Andrea Bittaud23ca152006-11-14 13:19:45 -0200366 break; /* old news */
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700367 }
368}
369
370static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200371 struct sock *sk, u64 *ackno,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700372 const unsigned char len,
373 const unsigned char *vector)
374{
375 unsigned char i;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800376 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700377
378 /* Check if we actually sent an ACK vector */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800379 if (list_empty(&av->av_records))
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700380 return;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700381
382 i = len;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800383 /*
384 * XXX
385 * I think it might be more efficient to work backwards. See comment on
386 * rcv_ackno. -sorbo.
387 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800388 avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700389 while (i--) {
390 const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
391 u64 ackno_end_rl;
392
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200393 dccp_set_seqno(&ackno_end_rl, *ackno - rl);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700394
395 /*
Andrea Bittau02bcf282006-03-20 17:19:55 -0800396 * If our AVR sequence number is greater than the ack, go
397 * forward in the AVR list until it is not so.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700398 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800399 list_for_each_entry_from(avr, &av->av_records, avr_node) {
400 if (!after48(avr->avr_ack_seqno, *ackno))
Andrea Bittau02bcf282006-03-20 17:19:55 -0800401 goto found;
402 }
Gerrit Renkera47c5102007-12-30 04:19:31 -0800403 /* End of the av_records list, not found, exit */
Andrea Bittau02bcf282006-03-20 17:19:55 -0800404 break;
405found:
Gerrit Renkera47c5102007-12-30 04:19:31 -0800406 if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) {
Andrea Bittau8e27e462006-09-19 13:05:35 -0700407 const u8 state = *vector & DCCP_ACKVEC_STATE_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700408 if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {
Gerrit Renker09dbc382006-11-14 12:57:34 -0200409 dccp_pr_debug("%s ACK vector 0, len=%d, "
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700410 "ack_seqno=%llu, ack_ackno=%llu, "
411 "ACKED!\n",
Gerrit Renker09dbc382006-11-14 12:57:34 -0200412 dccp_role(sk), len,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700413 (unsigned long long)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800414 avr->avr_ack_seqno,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700415 (unsigned long long)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800416 avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800417 dccp_ackvec_throw_record(av, avr);
Andrea Bittauafec35e2006-06-11 20:58:33 -0700418 break;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700419 }
420 /*
Andrea Bittau02bcf282006-03-20 17:19:55 -0800421 * If it wasn't received, continue scanning... we might
422 * find another one.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700423 */
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700424 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700425
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200426 dccp_set_seqno(ackno, ackno_end_rl - 1);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700427 ++vector;
428 }
429}
430
431int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200432 u64 *ackno, const u8 opt, const u8 *value, const u8 len)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700433{
Gerrit Renkerb20a9c22008-11-23 16:02:31 -0800434 if (len > DCCP_SINGLE_OPT_MAXLEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700435 return -1;
436
437 /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */
438 dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200439 ackno, len, value);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700440 return 0;
441}
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800442
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800443int __init dccp_ackvec_init(void)
444{
445 dccp_ackvec_slab = kmem_cache_create("dccp_ackvec",
446 sizeof(struct dccp_ackvec), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +0900447 SLAB_HWCACHE_ALIGN, NULL);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800448 if (dccp_ackvec_slab == NULL)
449 goto out_err;
450
451 dccp_ackvec_record_slab =
452 kmem_cache_create("dccp_ackvec_record",
453 sizeof(struct dccp_ackvec_record),
Paul Mundt20c2df82007-07-20 10:11:58 +0900454 0, SLAB_HWCACHE_ALIGN, NULL);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800455 if (dccp_ackvec_record_slab == NULL)
456 goto out_destroy_slab;
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800457
458 return 0;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800459
460out_destroy_slab:
461 kmem_cache_destroy(dccp_ackvec_slab);
462 dccp_ackvec_slab = NULL;
463out_err:
Gerrit Renker59348b12006-11-20 18:39:23 -0200464 DCCP_CRIT("Unable to create Ack Vector slab cache");
Andrea Bittau02bcf282006-03-20 17:19:55 -0800465 return -ENOBUFS;
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800466}
467
468void dccp_ackvec_exit(void)
469{
470 if (dccp_ackvec_slab != NULL) {
471 kmem_cache_destroy(dccp_ackvec_slab);
472 dccp_ackvec_slab = NULL;
473 }
Andrea Bittau02bcf282006-03-20 17:19:55 -0800474 if (dccp_ackvec_record_slab != NULL) {
475 kmem_cache_destroy(dccp_ackvec_record_slab);
476 dccp_ackvec_record_slab = NULL;
477 }
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800478}