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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
15#include <linux/dccp.h>
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080016#include <linux/init.h>
17#include <linux/errno.h>
18#include <linux/kernel.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070019#include <linux/skbuff.h>
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080020#include <linux/slab.h>
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070021
22#include <net/sock.h>
23
Christoph Lametere18b8902006-12-06 20:33:20 -080024static struct kmem_cache *dccp_ackvec_slab;
25static struct kmem_cache *dccp_ackvec_record_slab;
Andrea Bittau02bcf282006-03-20 17:19:55 -080026
27static struct dccp_ackvec_record *dccp_ackvec_record_new(void)
28{
29 struct dccp_ackvec_record *avr =
30 kmem_cache_alloc(dccp_ackvec_record_slab, GFP_ATOMIC);
31
32 if (avr != NULL)
Gerrit Renkera47c5102007-12-30 04:19:31 -080033 INIT_LIST_HEAD(&avr->avr_node);
Andrea Bittau02bcf282006-03-20 17:19:55 -080034
35 return avr;
36}
37
38static void dccp_ackvec_record_delete(struct dccp_ackvec_record *avr)
39{
40 if (unlikely(avr == NULL))
41 return;
42 /* Check if deleting a linked record */
Gerrit Renkera47c5102007-12-30 04:19:31 -080043 WARN_ON(!list_empty(&avr->avr_node));
Andrea Bittau02bcf282006-03-20 17:19:55 -080044 kmem_cache_free(dccp_ackvec_record_slab, avr);
45}
46
47static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
48 struct dccp_ackvec_record *avr)
49{
50 /*
51 * AVRs are sorted by seqno. Since we are sending them in order, we
52 * just add the AVR at the head of the list.
53 * -sorbo.
54 */
Gerrit Renkera47c5102007-12-30 04:19:31 -080055 if (!list_empty(&av->av_records)) {
Andrea Bittau02bcf282006-03-20 17:19:55 -080056 const struct dccp_ackvec_record *head =
Gerrit Renkera47c5102007-12-30 04:19:31 -080057 list_entry(av->av_records.next,
Andrea Bittau02bcf282006-03-20 17:19:55 -080058 struct dccp_ackvec_record,
Gerrit Renkera47c5102007-12-30 04:19:31 -080059 avr_node);
60 BUG_ON(before48(avr->avr_ack_seqno, head->avr_ack_seqno));
Andrea Bittau02bcf282006-03-20 17:19:55 -080061 }
62
Gerrit Renkera47c5102007-12-30 04:19:31 -080063 list_add(&avr->avr_node, &av->av_records);
Andrea Bittau02bcf282006-03-20 17:19:55 -080064}
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -080065
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070066int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
67{
68 struct dccp_sock *dp = dccp_sk(sk);
69 struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
Andrea Bittau522f1d02006-11-26 01:04:40 -020070 /* Figure out how many options do we need to represent the ackvec */
Gerrit Renkera47c5102007-12-30 04:19:31 -080071 const u16 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_MAX_ACKVEC_OPT_LEN);
72 u16 len = av->av_vec_len + 2 * nr_opts, i;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070073 u32 elapsed_time;
Andrea Bittau522f1d02006-11-26 01:04:40 -020074 const unsigned char *tail, *from;
75 unsigned char *to;
Andrea Bittau02bcf282006-03-20 17:19:55 -080076 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070077 suseconds_t delta;
Andrea Bittau02bcf282006-03-20 17:19:55 -080078
79 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
80 return -1;
81
Gerrit Renkera47c5102007-12-30 04:19:31 -080082 delta = ktime_us_delta(ktime_get_real(), av->av_time);
Arnaldo Carvalho de Melob8bda9d2007-08-19 17:17:25 -070083 elapsed_time = delta / 10;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070084
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -080085 if (elapsed_time != 0 &&
86 dccp_insert_option_elapsed_time(sk, skb, elapsed_time))
87 return -1;
88
89 avr = dccp_ackvec_record_new();
90 if (avr == NULL)
91 return -1;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070092
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070093 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
94
Andrea Bittau522f1d02006-11-26 01:04:40 -020095 to = skb_push(skb, len);
Gerrit Renkera47c5102007-12-30 04:19:31 -080096 len = av->av_vec_len;
97 from = av->av_buf + av->av_buf_head;
98 tail = av->av_buf + DCCP_MAX_ACKVEC_LEN;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070099
Andrea Bittau522f1d02006-11-26 01:04:40 -0200100 for (i = 0; i < nr_opts; ++i) {
101 int copylen = len;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700102
Andrea Bittau522f1d02006-11-26 01:04:40 -0200103 if (len > DCCP_MAX_ACKVEC_OPT_LEN)
104 copylen = DCCP_MAX_ACKVEC_OPT_LEN;
105
106 *to++ = DCCPO_ACK_VECTOR_0;
107 *to++ = copylen + 2;
108
109 /* Check if buf_head wraps */
110 if (from + copylen > tail) {
111 const u16 tailsize = tail - from;
112
113 memcpy(to, from, tailsize);
114 to += tailsize;
115 len -= tailsize;
116 copylen -= tailsize;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800117 from = av->av_buf;
Andrea Bittau522f1d02006-11-26 01:04:40 -0200118 }
119
120 memcpy(to, from, copylen);
121 from += copylen;
122 to += copylen;
123 len -= copylen;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700124 }
125
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700126 /*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700127 * From RFC 4340, A.2:
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700128 *
129 * For each acknowledgement it sends, the HC-Receiver will add an
130 * acknowledgement record. ack_seqno will equal the HC-Receiver
131 * sequence number it used for the ack packet; ack_ptr will equal
132 * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will
133 * equal buf_nonce.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700134 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800135 avr->avr_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
136 avr->avr_ack_ptr = av->av_buf_head;
137 avr->avr_ack_ackno = av->av_buf_ackno;
138 avr->avr_ack_nonce = av->av_buf_nonce;
139 avr->avr_sent_len = av->av_vec_len;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800140
141 dccp_ackvec_insert_avr(av, avr);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700142
Gerrit Renker09dbc382006-11-14 12:57:34 -0200143 dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700144 "ack_ackno=%llu\n",
Gerrit Renkera47c5102007-12-30 04:19:31 -0800145 dccp_role(sk), avr->avr_sent_len,
146 (unsigned long long)avr->avr_ack_seqno,
147 (unsigned long long)avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800148 return 0;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700149}
150
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800151struct dccp_ackvec *dccp_ackvec_alloc(const gfp_t priority)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700152{
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800153 struct dccp_ackvec *av = kmem_cache_alloc(dccp_ackvec_slab, priority);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700154
155 if (av != NULL) {
Gerrit Renkera47c5102007-12-30 04:19:31 -0800156 av->av_buf_head = DCCP_MAX_ACKVEC_LEN - 1;
157 av->av_buf_ackno = UINT48_MAX + 1;
158 av->av_buf_nonce = 0;
159 av->av_time = ktime_set(0, 0);
160 av->av_vec_len = 0;
161 INIT_LIST_HEAD(&av->av_records);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700162 }
163
164 return av;
165}
166
167void dccp_ackvec_free(struct dccp_ackvec *av)
168{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800169 if (unlikely(av == NULL))
170 return;
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800171
Gerrit Renkera47c5102007-12-30 04:19:31 -0800172 if (!list_empty(&av->av_records)) {
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800173 struct dccp_ackvec_record *avr, *next;
174
Gerrit Renkera47c5102007-12-30 04:19:31 -0800175 list_for_each_entry_safe(avr, next, &av->av_records, avr_node) {
176 list_del_init(&avr->avr_node);
Arnaldo Carvalho de Melod5e9b2c2006-03-20 17:20:46 -0800177 dccp_ackvec_record_delete(avr);
178 }
179 }
180
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800181 kmem_cache_free(dccp_ackvec_slab, av);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700182}
183
184static inline u8 dccp_ackvec_state(const struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200185 const u32 index)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700186{
Gerrit Renkera47c5102007-12-30 04:19:31 -0800187 return av->av_buf[index] & DCCP_ACKVEC_STATE_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700188}
189
190static inline u8 dccp_ackvec_len(const struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200191 const u32 index)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700192{
Gerrit Renkera47c5102007-12-30 04:19:31 -0800193 return av->av_buf[index] & DCCP_ACKVEC_LEN_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700194}
195
196/*
197 * If several packets are missing, the HC-Receiver may prefer to enter multiple
198 * bytes with run length 0, rather than a single byte with a larger run length;
199 * this simplifies table updates if one of the missing packets arrives.
200 */
201static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
202 const unsigned int packets,
Arnaldo Carvalho de Meloe4dfd4492006-01-04 01:46:34 -0200203 const unsigned char state)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700204{
205 unsigned int gap;
Kris Katterjohna8fc3d82006-01-17 13:03:54 -0800206 long new_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700207
Gerrit Renkera47c5102007-12-30 04:19:31 -0800208 if (av->av_vec_len + packets > DCCP_MAX_ACKVEC_LEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700209 return -ENOBUFS;
210
211 gap = packets - 1;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800212 new_head = av->av_buf_head - packets;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700213
214 if (new_head < 0) {
215 if (gap > 0) {
Gerrit Renkera47c5102007-12-30 04:19:31 -0800216 memset(av->av_buf, DCCP_ACKVEC_STATE_NOT_RECEIVED,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700217 gap + new_head + 1);
218 gap = -new_head;
219 }
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800220 new_head += DCCP_MAX_ACKVEC_LEN;
Arnaldo Carvalho de Melo8109b022006-12-10 16:01:18 -0200221 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700222
Gerrit Renkera47c5102007-12-30 04:19:31 -0800223 av->av_buf_head = new_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700224
225 if (gap > 0)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800226 memset(av->av_buf + av->av_buf_head + 1,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700227 DCCP_ACKVEC_STATE_NOT_RECEIVED, gap);
228
Gerrit Renkera47c5102007-12-30 04:19:31 -0800229 av->av_buf[av->av_buf_head] = state;
230 av->av_vec_len += packets;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700231 return 0;
232}
233
234/*
Gerrit Renker0e64e942006-10-24 16:17:51 -0700235 * Implements the RFC 4340, Appendix A
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700236 */
237int dccp_ackvec_add(struct dccp_ackvec *av, const struct sock *sk,
238 const u64 ackno, const u8 state)
239{
240 /*
241 * Check at the right places if the buffer is full, if it is, tell the
242 * caller to start dropping packets till the HC-Sender acks our ACK
Gerrit Renkera47c5102007-12-30 04:19:31 -0800243 * vectors, when we will free up space in av_buf.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700244 *
245 * We may well decide to do buffer compression, etc, but for now lets
246 * just drop.
247 *
Gerrit Renker0e64e942006-10-24 16:17:51 -0700248 * From Appendix A.1.1 (`New Packets'):
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700249 *
250 * Of course, the circular buffer may overflow, either when the
251 * HC-Sender is sending data at a very high rate, when the
252 * HC-Receiver's acknowledgements are not reaching the HC-Sender,
253 * or when the HC-Sender is forgetting to acknowledge those acks
254 * (so the HC-Receiver is unable to clean up old state). In this
255 * case, the HC-Receiver should either compress the buffer (by
256 * increasing run lengths when possible), transfer its state to
257 * a larger buffer, or, as a last resort, drop all received
258 * packets, without processing them whatsoever, until its buffer
259 * shrinks again.
260 */
261
262 /* See if this is the first ackno being inserted */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800263 if (av->av_vec_len == 0) {
264 av->av_buf[av->av_buf_head] = state;
265 av->av_vec_len = 1;
266 } else if (after48(ackno, av->av_buf_ackno)) {
267 const u64 delta = dccp_delta_seqno(av->av_buf_ackno, ackno);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700268
269 /*
270 * Look if the state of this packet is the same as the
271 * previous ackno and if so if we can bump the head len.
272 */
273 if (delta == 1 &&
Gerrit Renkera47c5102007-12-30 04:19:31 -0800274 dccp_ackvec_state(av, av->av_buf_head) == state &&
275 dccp_ackvec_len(av, av->av_buf_head) < DCCP_ACKVEC_LEN_MASK)
276 av->av_buf[av->av_buf_head]++;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700277 else if (dccp_ackvec_set_buf_head_state(av, delta, state))
278 return -ENOBUFS;
279 } else {
280 /*
281 * A.1.2. Old Packets
282 *
Gerrit Renker0e64e942006-10-24 16:17:51 -0700283 * When a packet with Sequence Number S <= buf_ackno
284 * arrives, the HC-Receiver will scan the table for
285 * the byte corresponding to S. (Indexing structures
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700286 * could reduce the complexity of this scan.)
287 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800288 u64 delta = dccp_delta_seqno(ackno, av->av_buf_ackno);
289 u32 index = av->av_buf_head;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700290
291 while (1) {
292 const u8 len = dccp_ackvec_len(av, index);
Gerrit Renker1e2f0e52008-06-11 11:19:09 +0100293 const u8 av_state = dccp_ackvec_state(av, index);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700294 /*
Gerrit Renkera47c5102007-12-30 04:19:31 -0800295 * valid packets not yet in av_buf have a reserved
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700296 * entry, with a len equal to 0.
297 */
Gerrit Renker1e2f0e52008-06-11 11:19:09 +0100298 if (av_state == DCCP_ACKVEC_STATE_NOT_RECEIVED &&
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700299 len == 0 && delta == 0) { /* Found our
300 reserved seat! */
301 dccp_pr_debug("Found %llu reserved seat!\n",
302 (unsigned long long)ackno);
Gerrit Renkera47c5102007-12-30 04:19:31 -0800303 av->av_buf[index] = state;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700304 goto out;
305 }
306 /* len == 0 means one packet */
307 if (delta < len + 1)
308 goto out_duplicate;
309
310 delta -= len + 1;
Arnaldo Carvalho de Melo7400d782006-03-20 17:15:42 -0800311 if (++index == DCCP_MAX_ACKVEC_LEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700312 index = 0;
313 }
314 }
315
Gerrit Renkera47c5102007-12-30 04:19:31 -0800316 av->av_buf_ackno = ackno;
317 av->av_time = ktime_get_real();
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700318out:
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700319 return 0;
320
321out_duplicate:
322 /* Duplicate packet */
323 dccp_pr_debug("Received a dup or already considered lost "
324 "packet: %llu\n", (unsigned long long)ackno);
325 return -EILSEQ;
326}
327
Andrea Bittau02bcf282006-03-20 17:19:55 -0800328static void dccp_ackvec_throw_record(struct dccp_ackvec *av,
329 struct dccp_ackvec_record *avr)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700330{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800331 struct dccp_ackvec_record *next;
332
Andrea Bittau23d06e32006-09-19 13:04:54 -0700333 /* sort out vector length */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800334 if (av->av_buf_head <= avr->avr_ack_ptr)
335 av->av_vec_len = avr->avr_ack_ptr - av->av_buf_head;
Andrea Bittau23d06e32006-09-19 13:04:54 -0700336 else
Gerrit Renkera47c5102007-12-30 04:19:31 -0800337 av->av_vec_len = DCCP_MAX_ACKVEC_LEN - 1 -
338 av->av_buf_head + avr->avr_ack_ptr;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800339
340 /* free records */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800341 list_for_each_entry_safe_from(avr, next, &av->av_records, avr_node) {
342 list_del_init(&avr->avr_node);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800343 dccp_ackvec_record_delete(avr);
344 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700345}
346
347void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
348 const u64 ackno)
349{
Andrea Bittau02bcf282006-03-20 17:19:55 -0800350 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700351
Andrea Bittau02bcf282006-03-20 17:19:55 -0800352 /*
353 * If we traverse backwards, it should be faster when we have large
354 * windows. We will be receiving ACKs for stuff we sent a while back
355 * -sorbo.
356 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800357 list_for_each_entry_reverse(avr, &av->av_records, avr_node) {
358 if (ackno == avr->avr_ack_seqno) {
Gerrit Renker09dbc382006-11-14 12:57:34 -0200359 dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, "
Andrea Bittau02bcf282006-03-20 17:19:55 -0800360 "ack_ackno=%llu, ACKED!\n",
Gerrit Renker09dbc382006-11-14 12:57:34 -0200361 dccp_role(sk), 1,
Gerrit Renkera47c5102007-12-30 04:19:31 -0800362 (unsigned long long)avr->avr_ack_seqno,
363 (unsigned long long)avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800364 dccp_ackvec_throw_record(av, avr);
365 break;
Gerrit Renkera47c5102007-12-30 04:19:31 -0800366 } else if (avr->avr_ack_seqno > ackno)
Andrea Bittaud23ca152006-11-14 13:19:45 -0200367 break; /* old news */
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700368 }
369}
370
371static void dccp_ackvec_check_rcv_ackvector(struct dccp_ackvec *av,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200372 struct sock *sk, u64 *ackno,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700373 const unsigned char len,
374 const unsigned char *vector)
375{
376 unsigned char i;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800377 struct dccp_ackvec_record *avr;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700378
379 /* Check if we actually sent an ACK vector */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800380 if (list_empty(&av->av_records))
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700381 return;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700382
383 i = len;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800384 /*
385 * XXX
386 * I think it might be more efficient to work backwards. See comment on
387 * rcv_ackno. -sorbo.
388 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800389 avr = list_entry(av->av_records.next, struct dccp_ackvec_record, avr_node);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700390 while (i--) {
391 const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK;
392 u64 ackno_end_rl;
393
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200394 dccp_set_seqno(&ackno_end_rl, *ackno - rl);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700395
396 /*
Andrea Bittau02bcf282006-03-20 17:19:55 -0800397 * If our AVR sequence number is greater than the ack, go
398 * forward in the AVR list until it is not so.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700399 */
Gerrit Renkera47c5102007-12-30 04:19:31 -0800400 list_for_each_entry_from(avr, &av->av_records, avr_node) {
401 if (!after48(avr->avr_ack_seqno, *ackno))
Andrea Bittau02bcf282006-03-20 17:19:55 -0800402 goto found;
403 }
Gerrit Renkera47c5102007-12-30 04:19:31 -0800404 /* End of the av_records list, not found, exit */
Andrea Bittau02bcf282006-03-20 17:19:55 -0800405 break;
406found:
Gerrit Renkera47c5102007-12-30 04:19:31 -0800407 if (between48(avr->avr_ack_seqno, ackno_end_rl, *ackno)) {
Andrea Bittau8e27e462006-09-19 13:05:35 -0700408 const u8 state = *vector & DCCP_ACKVEC_STATE_MASK;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700409 if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {
Gerrit Renker09dbc382006-11-14 12:57:34 -0200410 dccp_pr_debug("%s ACK vector 0, len=%d, "
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700411 "ack_seqno=%llu, ack_ackno=%llu, "
412 "ACKED!\n",
Gerrit Renker09dbc382006-11-14 12:57:34 -0200413 dccp_role(sk), len,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700414 (unsigned long long)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800415 avr->avr_ack_seqno,
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700416 (unsigned long long)
Gerrit Renkera47c5102007-12-30 04:19:31 -0800417 avr->avr_ack_ackno);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800418 dccp_ackvec_throw_record(av, avr);
Andrea Bittauafec35e2006-06-11 20:58:33 -0700419 break;
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700420 }
421 /*
Andrea Bittau02bcf282006-03-20 17:19:55 -0800422 * If it wasn't received, continue scanning... we might
423 * find another one.
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700424 */
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700425 }
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700426
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200427 dccp_set_seqno(ackno, ackno_end_rl - 1);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700428 ++vector;
429 }
430}
431
432int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200433 u64 *ackno, const u8 opt, const u8 *value, const u8 len)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700434{
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200435 if (len > DCCP_MAX_ACKVEC_OPT_LEN)
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700436 return -1;
437
438 /* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */
439 dccp_ackvec_check_rcv_ackvector(dccp_sk(sk)->dccps_hc_rx_ackvec, sk,
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200440 ackno, len, value);
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700441 return 0;
442}
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800443
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800444int __init dccp_ackvec_init(void)
445{
446 dccp_ackvec_slab = kmem_cache_create("dccp_ackvec",
447 sizeof(struct dccp_ackvec), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +0900448 SLAB_HWCACHE_ALIGN, NULL);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800449 if (dccp_ackvec_slab == NULL)
450 goto out_err;
451
452 dccp_ackvec_record_slab =
453 kmem_cache_create("dccp_ackvec_record",
454 sizeof(struct dccp_ackvec_record),
Paul Mundt20c2df82007-07-20 10:11:58 +0900455 0, SLAB_HWCACHE_ALIGN, NULL);
Andrea Bittau02bcf282006-03-20 17:19:55 -0800456 if (dccp_ackvec_record_slab == NULL)
457 goto out_destroy_slab;
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800458
459 return 0;
Andrea Bittau02bcf282006-03-20 17:19:55 -0800460
461out_destroy_slab:
462 kmem_cache_destroy(dccp_ackvec_slab);
463 dccp_ackvec_slab = NULL;
464out_err:
Gerrit Renker59348b12006-11-20 18:39:23 -0200465 DCCP_CRIT("Unable to create Ack Vector slab cache");
Andrea Bittau02bcf282006-03-20 17:19:55 -0800466 return -ENOBUFS;
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800467}
468
469void dccp_ackvec_exit(void)
470{
471 if (dccp_ackvec_slab != NULL) {
472 kmem_cache_destroy(dccp_ackvec_slab);
473 dccp_ackvec_slab = NULL;
474 }
Andrea Bittau02bcf282006-03-20 17:19:55 -0800475 if (dccp_ackvec_record_slab != NULL) {
476 kmem_cache_destroy(dccp_ackvec_record_slab);
477 dccp_ackvec_record_slab = NULL;
478 }
Arnaldo Carvalho de Melo9b07ef52006-03-20 17:16:17 -0800479}