Commit | Line | Data |
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2a91aa39 AB |
1 | /* |
2 | * net/dccp/ccids/ccid2.c | |
3 | * | |
4 | * Copyright (c) 2005, 2006 Andrea Bittau <a.bittau@cs.ucl.ac.uk> | |
5 | * | |
6 | * Changes to meet Linux coding standards, and DCCP infrastructure fixes. | |
7 | * | |
8 | * Copyright (c) 2006 Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License as published by | |
12 | * the Free Software Foundation; either version 2 of the License, or | |
13 | * (at your option) any later version. | |
14 | * | |
15 | * This program is distributed in the hope that it will be useful, | |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | * GNU General Public License for more details. | |
19 | * | |
20 | * You should have received a copy of the GNU General Public License | |
21 | * along with this program; if not, write to the Free Software | |
22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
23 | */ | |
24 | ||
25 | /* | |
0e64e94e | 26 | * This implementation should follow RFC 4341 |
2a91aa39 AB |
27 | */ |
28 | ||
2a91aa39 AB |
29 | #include "../ccid.h" |
30 | #include "../dccp.h" | |
31 | #include "ccid2.h" | |
32 | ||
2a91aa39 | 33 | |
8d424f6c | 34 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
84116716 GR |
35 | static int ccid2_debug; |
36 | #define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) | |
2a91aa39 | 37 | |
2a91aa39 AB |
38 | static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx) |
39 | { | |
40 | int len = 0; | |
2a91aa39 | 41 | int pipe = 0; |
c0c736db | 42 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqh; |
2a91aa39 AB |
43 | |
44 | /* there is data in the chain */ | |
45 | if (seqp != hctx->ccid2hctx_seqt) { | |
46 | seqp = seqp->ccid2s_prev; | |
47 | len++; | |
48 | if (!seqp->ccid2s_acked) | |
49 | pipe++; | |
50 | ||
51 | while (seqp != hctx->ccid2hctx_seqt) { | |
c0c736db | 52 | struct ccid2_seq *prev = seqp->ccid2s_prev; |
2a91aa39 | 53 | |
2a91aa39 AB |
54 | len++; |
55 | if (!prev->ccid2s_acked) | |
56 | pipe++; | |
57 | ||
58 | /* packets are sent sequentially */ | |
5e28599a GR |
59 | BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq, |
60 | prev->ccid2s_seq ) >= 0); | |
29651cda AB |
61 | BUG_ON(time_before(seqp->ccid2s_sent, |
62 | prev->ccid2s_sent)); | |
2a91aa39 AB |
63 | |
64 | seqp = prev; | |
65 | } | |
66 | } | |
67 | ||
68 | BUG_ON(pipe != hctx->ccid2hctx_pipe); | |
69 | ccid2_pr_debug("len of chain=%d\n", len); | |
70 | ||
71 | do { | |
72 | seqp = seqp->ccid2s_prev; | |
73 | len++; | |
c0c736db | 74 | } while (seqp != hctx->ccid2hctx_seqh); |
2a91aa39 | 75 | |
2a91aa39 | 76 | ccid2_pr_debug("total len=%d\n", len); |
07978aab | 77 | BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN); |
2a91aa39 AB |
78 | } |
79 | #else | |
84116716 GR |
80 | #define ccid2_pr_debug(format, a...) |
81 | #define ccid2_hc_tx_check_sanity(hctx) | |
2a91aa39 AB |
82 | #endif |
83 | ||
cd1f7d34 | 84 | static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) |
07978aab AB |
85 | { |
86 | struct ccid2_seq *seqp; | |
87 | int i; | |
88 | ||
89 | /* check if we have space to preserve the pointer to the buffer */ | |
90 | if (hctx->ccid2hctx_seqbufc >= (sizeof(hctx->ccid2hctx_seqbuf) / | |
91 | sizeof(struct ccid2_seq*))) | |
92 | return -ENOMEM; | |
93 | ||
94 | /* allocate buffer and initialize linked list */ | |
cd1f7d34 | 95 | seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any()); |
07978aab AB |
96 | if (seqp == NULL) |
97 | return -ENOMEM; | |
98 | ||
cd1f7d34 | 99 | for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) { |
07978aab AB |
100 | seqp[i].ccid2s_next = &seqp[i + 1]; |
101 | seqp[i + 1].ccid2s_prev = &seqp[i]; | |
102 | } | |
cd1f7d34 GR |
103 | seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp; |
104 | seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; | |
07978aab AB |
105 | |
106 | /* This is the first allocation. Initiate the head and tail. */ | |
107 | if (hctx->ccid2hctx_seqbufc == 0) | |
108 | hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqt = seqp; | |
109 | else { | |
110 | /* link the existing list with the one we just created */ | |
111 | hctx->ccid2hctx_seqh->ccid2s_next = seqp; | |
112 | seqp->ccid2s_prev = hctx->ccid2hctx_seqh; | |
113 | ||
cd1f7d34 GR |
114 | hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; |
115 | seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt; | |
07978aab AB |
116 | } |
117 | ||
118 | /* store the original pointer to the buffer so we can free it */ | |
119 | hctx->ccid2hctx_seqbuf[hctx->ccid2hctx_seqbufc] = seqp; | |
120 | hctx->ccid2hctx_seqbufc++; | |
121 | ||
122 | return 0; | |
123 | } | |
124 | ||
6b57c93d | 125 | static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
2a91aa39 | 126 | { |
6c583248 | 127 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
128 | |
129 | ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe, | |
130 | hctx->ccid2hctx_cwnd); | |
131 | ||
132 | if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { | |
133 | /* OK we can send... make sure previous packet was sent off */ | |
134 | if (!hctx->ccid2hctx_sendwait) { | |
135 | hctx->ccid2hctx_sendwait = 1; | |
136 | return 0; | |
137 | } | |
138 | } | |
139 | ||
446dec30 | 140 | return 1; /* XXX CCID should dequeue when ready instead of polling */ |
2a91aa39 AB |
141 | } |
142 | ||
143 | static void ccid2_change_l_ack_ratio(struct sock *sk, int val) | |
144 | { | |
145 | struct dccp_sock *dp = dccp_sk(sk); | |
146 | /* | |
147 | * XXX I don't really agree with val != 2. If cwnd is 1, ack ratio | |
148 | * should be 1... it shouldn't be allowed to become 2. | |
149 | * -sorbo. | |
150 | */ | |
151 | if (val != 2) { | |
c0c736db | 152 | const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
153 | int max = hctx->ccid2hctx_cwnd / 2; |
154 | ||
155 | /* round up */ | |
156 | if (hctx->ccid2hctx_cwnd & 1) | |
157 | max++; | |
158 | ||
159 | if (val > max) | |
160 | val = max; | |
161 | } | |
162 | ||
163 | ccid2_pr_debug("changing local ack ratio to %d\n", val); | |
164 | WARN_ON(val <= 0); | |
165 | dp->dccps_l_ack_ratio = val; | |
166 | } | |
167 | ||
ee196c21 | 168 | static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, u32 val) |
2a91aa39 | 169 | { |
2a91aa39 | 170 | /* XXX do we need to change ack ratio? */ |
ee196c21 GR |
171 | hctx->ccid2hctx_cwnd = val? : 1; |
172 | ccid2_pr_debug("changed cwnd to %u\n", hctx->ccid2hctx_cwnd); | |
2a91aa39 AB |
173 | } |
174 | ||
593f16aa AB |
175 | static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) |
176 | { | |
177 | ccid2_pr_debug("change SRTT to %ld\n", val); | |
178 | hctx->ccid2hctx_srtt = val; | |
179 | } | |
180 | ||
181 | static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val) | |
182 | { | |
183 | hctx->ccid2hctx_pipe = val; | |
184 | } | |
185 | ||
2a91aa39 AB |
186 | static void ccid2_start_rto_timer(struct sock *sk); |
187 | ||
188 | static void ccid2_hc_tx_rto_expire(unsigned long data) | |
189 | { | |
190 | struct sock *sk = (struct sock *)data; | |
191 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
192 | long s; | |
193 | ||
2a91aa39 AB |
194 | bh_lock_sock(sk); |
195 | if (sock_owned_by_user(sk)) { | |
196 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
197 | jiffies + HZ / 5); | |
198 | goto out; | |
199 | } | |
200 | ||
201 | ccid2_pr_debug("RTO_EXPIRE\n"); | |
202 | ||
203 | ccid2_hc_tx_check_sanity(hctx); | |
204 | ||
205 | /* back-off timer */ | |
206 | hctx->ccid2hctx_rto <<= 1; | |
207 | ||
208 | s = hctx->ccid2hctx_rto / HZ; | |
209 | if (s > 60) | |
210 | hctx->ccid2hctx_rto = 60 * HZ; | |
211 | ||
212 | ccid2_start_rto_timer(sk); | |
213 | ||
214 | /* adjust pipe, cwnd etc */ | |
593f16aa | 215 | ccid2_change_pipe(hctx, 0); |
2a91aa39 AB |
216 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
217 | if (hctx->ccid2hctx_ssthresh < 2) | |
218 | hctx->ccid2hctx_ssthresh = 2; | |
374bcf32 | 219 | ccid2_change_cwnd(hctx, 1); |
2a91aa39 AB |
220 | |
221 | /* clear state about stuff we sent */ | |
222 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; | |
223 | hctx->ccid2hctx_ssacks = 0; | |
224 | hctx->ccid2hctx_acks = 0; | |
225 | hctx->ccid2hctx_sent = 0; | |
226 | ||
227 | /* clear ack ratio state. */ | |
228 | hctx->ccid2hctx_arsent = 0; | |
229 | hctx->ccid2hctx_ackloss = 0; | |
230 | hctx->ccid2hctx_rpseq = 0; | |
231 | hctx->ccid2hctx_rpdupack = -1; | |
232 | ccid2_change_l_ack_ratio(sk, 1); | |
233 | ccid2_hc_tx_check_sanity(hctx); | |
234 | out: | |
235 | bh_unlock_sock(sk); | |
77ff72d5 | 236 | sock_put(sk); |
2a91aa39 AB |
237 | } |
238 | ||
239 | static void ccid2_start_rto_timer(struct sock *sk) | |
240 | { | |
241 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
242 | ||
243 | ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); | |
244 | ||
245 | BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); | |
246 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
247 | jiffies + hctx->ccid2hctx_rto); | |
248 | } | |
249 | ||
6b57c93d | 250 | static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) |
2a91aa39 AB |
251 | { |
252 | struct dccp_sock *dp = dccp_sk(sk); | |
253 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
07978aab | 254 | struct ccid2_seq *next; |
2a91aa39 AB |
255 | u64 seq; |
256 | ||
257 | ccid2_hc_tx_check_sanity(hctx); | |
258 | ||
259 | BUG_ON(!hctx->ccid2hctx_sendwait); | |
260 | hctx->ccid2hctx_sendwait = 0; | |
593f16aa | 261 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1); |
2a91aa39 AB |
262 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
263 | ||
264 | /* There is an issue. What if another packet is sent between | |
265 | * packet_send() and packet_sent(). Then the sequence number would be | |
266 | * wrong. | |
267 | * -sorbo. | |
268 | */ | |
269 | seq = dp->dccps_gss; | |
270 | ||
271 | hctx->ccid2hctx_seqh->ccid2s_seq = seq; | |
272 | hctx->ccid2hctx_seqh->ccid2s_acked = 0; | |
273 | hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; | |
2a91aa39 | 274 | |
07978aab AB |
275 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
276 | /* check if we need to alloc more space */ | |
277 | if (next == hctx->ccid2hctx_seqt) { | |
7d9e8931 GR |
278 | if (ccid2_hc_tx_alloc_seq(hctx)) { |
279 | DCCP_CRIT("packet history - out of memory!"); | |
280 | /* FIXME: find a more graceful way to bail out */ | |
281 | return; | |
282 | } | |
07978aab AB |
283 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
284 | BUG_ON(next == hctx->ccid2hctx_seqt); | |
2a91aa39 | 285 | } |
07978aab AB |
286 | hctx->ccid2hctx_seqh = next; |
287 | ||
288 | ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, | |
289 | hctx->ccid2hctx_pipe); | |
2a91aa39 AB |
290 | |
291 | hctx->ccid2hctx_sent++; | |
292 | ||
293 | /* Ack Ratio. Need to maintain a concept of how many windows we sent */ | |
294 | hctx->ccid2hctx_arsent++; | |
295 | /* We had an ack loss in this window... */ | |
296 | if (hctx->ccid2hctx_ackloss) { | |
297 | if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { | |
c0c736db ACM |
298 | hctx->ccid2hctx_arsent = 0; |
299 | hctx->ccid2hctx_ackloss = 0; | |
2a91aa39 | 300 | } |
c0c736db ACM |
301 | } else { |
302 | /* No acks lost up to now... */ | |
2a91aa39 AB |
303 | /* decrease ack ratio if enough packets were sent */ |
304 | if (dp->dccps_l_ack_ratio > 1) { | |
305 | /* XXX don't calculate denominator each time */ | |
c0c736db ACM |
306 | int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - |
307 | dp->dccps_l_ack_ratio; | |
2a91aa39 | 308 | |
2a91aa39 AB |
309 | denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; |
310 | ||
311 | if (hctx->ccid2hctx_arsent >= denom) { | |
312 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); | |
313 | hctx->ccid2hctx_arsent = 0; | |
314 | } | |
c0c736db ACM |
315 | } else { |
316 | /* we can't increase ack ratio further [1] */ | |
2a91aa39 AB |
317 | hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ |
318 | } | |
319 | } | |
320 | ||
321 | /* setup RTO timer */ | |
c0c736db | 322 | if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
2a91aa39 | 323 | ccid2_start_rto_timer(sk); |
c0c736db | 324 | |
8d424f6c | 325 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
2a91aa39 | 326 | ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
234af484 | 327 | ccid2_pr_debug("Sent: seq=%llu\n", (unsigned long long)seq); |
2a91aa39 AB |
328 | do { |
329 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; | |
330 | ||
331 | while (seqp != hctx->ccid2hctx_seqh) { | |
332 | ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", | |
8109b02b | 333 | (unsigned long long)seqp->ccid2s_seq, |
234af484 | 334 | seqp->ccid2s_acked, seqp->ccid2s_sent); |
2a91aa39 AB |
335 | seqp = seqp->ccid2s_next; |
336 | } | |
c0c736db | 337 | } while (0); |
2a91aa39 AB |
338 | ccid2_pr_debug("=========\n"); |
339 | ccid2_hc_tx_check_sanity(hctx); | |
340 | #endif | |
341 | } | |
342 | ||
343 | /* XXX Lame code duplication! | |
344 | * returns -1 if none was found. | |
345 | * else returns the next offset to use in the function call. | |
346 | */ | |
347 | static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, | |
348 | unsigned char **vec, unsigned char *veclen) | |
349 | { | |
c9eaf173 YH |
350 | const struct dccp_hdr *dh = dccp_hdr(skb); |
351 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
352 | unsigned char *opt_ptr; | |
353 | const unsigned char *opt_end = (unsigned char *)dh + | |
354 | (dh->dccph_doff * 4); | |
355 | unsigned char opt, len; | |
356 | unsigned char *value; | |
2a91aa39 AB |
357 | |
358 | BUG_ON(offset < 0); | |
359 | options += offset; | |
360 | opt_ptr = options; | |
361 | if (opt_ptr >= opt_end) | |
362 | return -1; | |
363 | ||
364 | while (opt_ptr != opt_end) { | |
c9eaf173 YH |
365 | opt = *opt_ptr++; |
366 | len = 0; | |
367 | value = NULL; | |
368 | ||
369 | /* Check if this isn't a single byte option */ | |
370 | if (opt > DCCPO_MAX_RESERVED) { | |
371 | if (opt_ptr == opt_end) | |
372 | goto out_invalid_option; | |
373 | ||
374 | len = *opt_ptr++; | |
375 | if (len < 3) | |
376 | goto out_invalid_option; | |
377 | /* | |
378 | * Remove the type and len fields, leaving | |
379 | * just the value size | |
380 | */ | |
381 | len -= 2; | |
382 | value = opt_ptr; | |
383 | opt_ptr += len; | |
384 | ||
385 | if (opt_ptr > opt_end) | |
386 | goto out_invalid_option; | |
387 | } | |
2a91aa39 AB |
388 | |
389 | switch (opt) { | |
390 | case DCCPO_ACK_VECTOR_0: | |
391 | case DCCPO_ACK_VECTOR_1: | |
392 | *vec = value; | |
393 | *veclen = len; | |
394 | return offset + (opt_ptr - options); | |
2a91aa39 AB |
395 | } |
396 | } | |
397 | ||
398 | return -1; | |
399 | ||
400 | out_invalid_option: | |
59348b19 | 401 | DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); |
2a91aa39 AB |
402 | return -1; |
403 | } | |
404 | ||
77ff72d5 | 405 | static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) |
2a91aa39 | 406 | { |
77ff72d5 AB |
407 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
408 | ||
409 | sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); | |
410 | ccid2_pr_debug("deleted RTO timer\n"); | |
2a91aa39 AB |
411 | } |
412 | ||
413 | static inline void ccid2_new_ack(struct sock *sk, | |
c9eaf173 | 414 | struct ccid2_seq *seqp, |
2a91aa39 AB |
415 | unsigned int *maxincr) |
416 | { | |
417 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
418 | ||
419 | /* slow start */ | |
420 | if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { | |
421 | hctx->ccid2hctx_acks = 0; | |
422 | ||
423 | /* We can increase cwnd at most maxincr [ack_ratio/2] */ | |
424 | if (*maxincr) { | |
425 | /* increase every 2 acks */ | |
426 | hctx->ccid2hctx_ssacks++; | |
427 | if (hctx->ccid2hctx_ssacks == 2) { | |
374bcf32 | 428 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd+1); |
2a91aa39 AB |
429 | hctx->ccid2hctx_ssacks = 0; |
430 | *maxincr = *maxincr - 1; | |
431 | } | |
c0c736db ACM |
432 | } else { |
433 | /* increased cwnd enough for this single ack */ | |
2a91aa39 AB |
434 | hctx->ccid2hctx_ssacks = 0; |
435 | } | |
c0c736db | 436 | } else { |
2a91aa39 AB |
437 | hctx->ccid2hctx_ssacks = 0; |
438 | hctx->ccid2hctx_acks++; | |
439 | ||
440 | if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { | |
374bcf32 | 441 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd + 1); |
2a91aa39 AB |
442 | hctx->ccid2hctx_acks = 0; |
443 | } | |
444 | } | |
445 | ||
446 | /* update RTO */ | |
447 | if (hctx->ccid2hctx_srtt == -1 || | |
29651cda AB |
448 | time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { |
449 | unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; | |
2a91aa39 AB |
450 | int s; |
451 | ||
452 | /* first measurement */ | |
453 | if (hctx->ccid2hctx_srtt == -1) { | |
454 | ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", | |
8109b02b | 455 | r, jiffies, |
234af484 | 456 | (unsigned long long)seqp->ccid2s_seq); |
593f16aa | 457 | ccid2_change_srtt(hctx, r); |
2a91aa39 | 458 | hctx->ccid2hctx_rttvar = r >> 1; |
c0c736db | 459 | } else { |
2a91aa39 AB |
460 | /* RTTVAR */ |
461 | long tmp = hctx->ccid2hctx_srtt - r; | |
593f16aa AB |
462 | long srtt; |
463 | ||
2a91aa39 AB |
464 | if (tmp < 0) |
465 | tmp *= -1; | |
466 | ||
467 | tmp >>= 2; | |
468 | hctx->ccid2hctx_rttvar *= 3; | |
469 | hctx->ccid2hctx_rttvar >>= 2; | |
470 | hctx->ccid2hctx_rttvar += tmp; | |
471 | ||
472 | /* SRTT */ | |
593f16aa AB |
473 | srtt = hctx->ccid2hctx_srtt; |
474 | srtt *= 7; | |
475 | srtt >>= 3; | |
2a91aa39 | 476 | tmp = r >> 3; |
593f16aa AB |
477 | srtt += tmp; |
478 | ccid2_change_srtt(hctx, srtt); | |
2a91aa39 AB |
479 | } |
480 | s = hctx->ccid2hctx_rttvar << 2; | |
481 | /* clock granularity is 1 when based on jiffies */ | |
482 | if (!s) | |
483 | s = 1; | |
484 | hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; | |
485 | ||
486 | /* must be at least a second */ | |
487 | s = hctx->ccid2hctx_rto / HZ; | |
488 | /* DCCP doesn't require this [but I like it cuz my code sux] */ | |
489 | #if 1 | |
490 | if (s < 1) | |
491 | hctx->ccid2hctx_rto = HZ; | |
492 | #endif | |
493 | /* max 60 seconds */ | |
494 | if (s > 60) | |
495 | hctx->ccid2hctx_rto = HZ * 60; | |
496 | ||
497 | hctx->ccid2hctx_lastrtt = jiffies; | |
498 | ||
499 | ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", | |
8109b02b ACM |
500 | hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, |
501 | hctx->ccid2hctx_rto, HZ, r); | |
2a91aa39 AB |
502 | hctx->ccid2hctx_sent = 0; |
503 | } | |
504 | ||
505 | /* we got a new ack, so re-start RTO timer */ | |
77ff72d5 | 506 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
507 | ccid2_start_rto_timer(sk); |
508 | } | |
509 | ||
77ff72d5 | 510 | static void ccid2_hc_tx_dec_pipe(struct sock *sk) |
2a91aa39 | 511 | { |
77ff72d5 AB |
512 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
513 | ||
593f16aa | 514 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1); |
2a91aa39 AB |
515 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
516 | ||
517 | if (hctx->ccid2hctx_pipe == 0) | |
77ff72d5 | 518 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
519 | } |
520 | ||
374bcf32 AB |
521 | static void ccid2_congestion_event(struct ccid2_hc_tx_sock *hctx, |
522 | struct ccid2_seq *seqp) | |
523 | { | |
524 | if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { | |
525 | ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); | |
526 | return; | |
527 | } | |
528 | ||
529 | hctx->ccid2hctx_last_cong = jiffies; | |
530 | ||
531 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1); | |
532 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; | |
533 | if (hctx->ccid2hctx_ssthresh < 2) | |
534 | hctx->ccid2hctx_ssthresh = 2; | |
535 | } | |
536 | ||
2a91aa39 AB |
537 | static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |
538 | { | |
539 | struct dccp_sock *dp = dccp_sk(sk); | |
540 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
541 | u64 ackno, seqno; | |
542 | struct ccid2_seq *seqp; | |
543 | unsigned char *vector; | |
544 | unsigned char veclen; | |
545 | int offset = 0; | |
546 | int done = 0; | |
2a91aa39 AB |
547 | unsigned int maxincr = 0; |
548 | ||
549 | ccid2_hc_tx_check_sanity(hctx); | |
550 | /* check reverse path congestion */ | |
551 | seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
552 | ||
553 | /* XXX this whole "algorithm" is broken. Need to fix it to keep track | |
554 | * of the seqnos of the dupacks so that rpseq and rpdupack are correct | |
555 | * -sorbo. | |
556 | */ | |
557 | /* need to bootstrap */ | |
558 | if (hctx->ccid2hctx_rpdupack == -1) { | |
559 | hctx->ccid2hctx_rpdupack = 0; | |
560 | hctx->ccid2hctx_rpseq = seqno; | |
c0c736db | 561 | } else { |
2a91aa39 | 562 | /* check if packet is consecutive */ |
5e28599a GR |
563 | if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1) |
564 | hctx->ccid2hctx_rpseq = seqno; | |
2a91aa39 AB |
565 | /* it's a later packet */ |
566 | else if (after48(seqno, hctx->ccid2hctx_rpseq)) { | |
567 | hctx->ccid2hctx_rpdupack++; | |
568 | ||
569 | /* check if we got enough dupacks */ | |
570 | if (hctx->ccid2hctx_rpdupack >= | |
571 | hctx->ccid2hctx_numdupack) { | |
2a91aa39 AB |
572 | hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
573 | hctx->ccid2hctx_rpseq = 0; | |
574 | ||
575 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1); | |
576 | } | |
577 | } | |
578 | } | |
579 | ||
580 | /* check forward path congestion */ | |
581 | /* still didn't send out new data packets */ | |
582 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) | |
583 | return; | |
584 | ||
585 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
586 | case DCCP_PKT_ACK: | |
587 | case DCCP_PKT_DATAACK: | |
588 | break; | |
2a91aa39 AB |
589 | default: |
590 | return; | |
591 | } | |
592 | ||
593 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
32aac18d AB |
594 | if (after48(ackno, hctx->ccid2hctx_high_ack)) |
595 | hctx->ccid2hctx_high_ack = ackno; | |
596 | ||
597 | seqp = hctx->ccid2hctx_seqt; | |
598 | while (before48(seqp->ccid2s_seq, ackno)) { | |
599 | seqp = seqp->ccid2s_next; | |
600 | if (seqp == hctx->ccid2hctx_seqh) { | |
601 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
602 | break; | |
603 | } | |
604 | } | |
2a91aa39 AB |
605 | |
606 | /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for | |
607 | * this single ack. I round up. | |
608 | * -sorbo. | |
609 | */ | |
610 | maxincr = dp->dccps_l_ack_ratio >> 1; | |
611 | maxincr++; | |
612 | ||
613 | /* go through all ack vectors */ | |
614 | while ((offset = ccid2_ackvector(sk, skb, offset, | |
615 | &vector, &veclen)) != -1) { | |
616 | /* go through this ack vector */ | |
617 | while (veclen--) { | |
618 | const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; | |
cfbbeabc | 619 | u64 ackno_end_rl = SUB48(ackno, rl); |
2a91aa39 | 620 | |
234af484 RD |
621 | ccid2_pr_debug("ackvec start:%llu end:%llu\n", |
622 | (unsigned long long)ackno, | |
623 | (unsigned long long)ackno_end_rl); | |
2a91aa39 AB |
624 | /* if the seqno we are analyzing is larger than the |
625 | * current ackno, then move towards the tail of our | |
626 | * seqnos. | |
627 | */ | |
628 | while (after48(seqp->ccid2s_seq, ackno)) { | |
629 | if (seqp == hctx->ccid2hctx_seqt) { | |
630 | done = 1; | |
631 | break; | |
632 | } | |
633 | seqp = seqp->ccid2s_prev; | |
634 | } | |
635 | if (done) | |
636 | break; | |
637 | ||
638 | /* check all seqnos in the range of the vector | |
639 | * run length | |
640 | */ | |
641 | while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { | |
8e27e465 AB |
642 | const u8 state = *vector & |
643 | DCCP_ACKVEC_STATE_MASK; | |
2a91aa39 AB |
644 | |
645 | /* new packet received or marked */ | |
646 | if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && | |
647 | !seqp->ccid2s_acked) { | |
8109b02b | 648 | if (state == |
2a91aa39 | 649 | DCCP_ACKVEC_STATE_ECN_MARKED) { |
8109b02b | 650 | ccid2_congestion_event(hctx, |
374bcf32 | 651 | seqp); |
c0c736db | 652 | } else |
2a91aa39 AB |
653 | ccid2_new_ack(sk, seqp, |
654 | &maxincr); | |
2a91aa39 AB |
655 | |
656 | seqp->ccid2s_acked = 1; | |
657 | ccid2_pr_debug("Got ack for %llu\n", | |
234af484 | 658 | (unsigned long long)seqp->ccid2s_seq); |
77ff72d5 | 659 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
660 | } |
661 | if (seqp == hctx->ccid2hctx_seqt) { | |
662 | done = 1; | |
663 | break; | |
664 | } | |
3de5489f | 665 | seqp = seqp->ccid2s_prev; |
2a91aa39 AB |
666 | } |
667 | if (done) | |
668 | break; | |
669 | ||
cfbbeabc | 670 | ackno = SUB48(ackno_end_rl, 1); |
2a91aa39 AB |
671 | vector++; |
672 | } | |
673 | if (done) | |
674 | break; | |
675 | } | |
676 | ||
677 | /* The state about what is acked should be correct now | |
678 | * Check for NUMDUPACK | |
679 | */ | |
32aac18d AB |
680 | seqp = hctx->ccid2hctx_seqt; |
681 | while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { | |
682 | seqp = seqp->ccid2s_next; | |
683 | if (seqp == hctx->ccid2hctx_seqh) { | |
684 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
685 | break; | |
686 | } | |
687 | } | |
2a91aa39 AB |
688 | done = 0; |
689 | while (1) { | |
690 | if (seqp->ccid2s_acked) { | |
691 | done++; | |
c0c736db | 692 | if (done == hctx->ccid2hctx_numdupack) |
2a91aa39 | 693 | break; |
2a91aa39 | 694 | } |
c0c736db | 695 | if (seqp == hctx->ccid2hctx_seqt) |
2a91aa39 | 696 | break; |
2a91aa39 AB |
697 | seqp = seqp->ccid2s_prev; |
698 | } | |
699 | ||
700 | /* If there are at least 3 acknowledgements, anything unacknowledged | |
701 | * below the last sequence number is considered lost | |
702 | */ | |
703 | if (done == hctx->ccid2hctx_numdupack) { | |
704 | struct ccid2_seq *last_acked = seqp; | |
705 | ||
706 | /* check for lost packets */ | |
707 | while (1) { | |
708 | if (!seqp->ccid2s_acked) { | |
374bcf32 | 709 | ccid2_pr_debug("Packet lost: %llu\n", |
234af484 | 710 | (unsigned long long)seqp->ccid2s_seq); |
374bcf32 AB |
711 | /* XXX need to traverse from tail -> head in |
712 | * order to detect multiple congestion events in | |
713 | * one ack vector. | |
714 | */ | |
715 | ccid2_congestion_event(hctx, seqp); | |
77ff72d5 | 716 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
717 | } |
718 | if (seqp == hctx->ccid2hctx_seqt) | |
719 | break; | |
720 | seqp = seqp->ccid2s_prev; | |
721 | } | |
722 | ||
723 | hctx->ccid2hctx_seqt = last_acked; | |
724 | } | |
725 | ||
726 | /* trim acked packets in tail */ | |
727 | while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { | |
728 | if (!hctx->ccid2hctx_seqt->ccid2s_acked) | |
729 | break; | |
730 | ||
731 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; | |
732 | } | |
733 | ||
2a91aa39 AB |
734 | ccid2_hc_tx_check_sanity(hctx); |
735 | } | |
736 | ||
91f0ebf7 | 737 | static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) |
2a91aa39 | 738 | { |
c9eaf173 | 739 | struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); |
2a91aa39 | 740 | |
374bcf32 | 741 | ccid2_change_cwnd(hctx, 1); |
d458c25c AB |
742 | /* Initialize ssthresh to infinity. This means that we will exit the |
743 | * initial slow-start after the first packet loss. This is what we | |
744 | * want. | |
745 | */ | |
746 | hctx->ccid2hctx_ssthresh = ~0; | |
2a91aa39 AB |
747 | hctx->ccid2hctx_numdupack = 3; |
748 | ||
749 | /* XXX init ~ to window size... */ | |
cd1f7d34 | 750 | if (ccid2_hc_tx_alloc_seq(hctx)) |
2a91aa39 | 751 | return -ENOMEM; |
91f0ebf7 | 752 | |
2a91aa39 | 753 | hctx->ccid2hctx_rto = 3 * HZ; |
593f16aa | 754 | ccid2_change_srtt(hctx, -1); |
2a91aa39 | 755 | hctx->ccid2hctx_rttvar = -1; |
2a91aa39 | 756 | hctx->ccid2hctx_rpdupack = -1; |
374bcf32 | 757 | hctx->ccid2hctx_last_cong = jiffies; |
b24b8a24 PE |
758 | setup_timer(&hctx->ccid2hctx_rtotimer, ccid2_hc_tx_rto_expire, |
759 | (unsigned long)sk); | |
2a91aa39 AB |
760 | |
761 | ccid2_hc_tx_check_sanity(hctx); | |
762 | return 0; | |
763 | } | |
764 | ||
765 | static void ccid2_hc_tx_exit(struct sock *sk) | |
766 | { | |
c9eaf173 | 767 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
07978aab | 768 | int i; |
2a91aa39 | 769 | |
77ff72d5 | 770 | ccid2_hc_tx_kill_rto_timer(sk); |
07978aab AB |
771 | |
772 | for (i = 0; i < hctx->ccid2hctx_seqbufc; i++) | |
773 | kfree(hctx->ccid2hctx_seqbuf[i]); | |
774 | hctx->ccid2hctx_seqbufc = 0; | |
2a91aa39 AB |
775 | } |
776 | ||
777 | static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
778 | { | |
779 | const struct dccp_sock *dp = dccp_sk(sk); | |
780 | struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk); | |
781 | ||
782 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
783 | case DCCP_PKT_DATA: | |
784 | case DCCP_PKT_DATAACK: | |
785 | hcrx->ccid2hcrx_data++; | |
786 | if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { | |
787 | dccp_send_ack(sk); | |
788 | hcrx->ccid2hcrx_data = 0; | |
789 | } | |
790 | break; | |
791 | } | |
792 | } | |
793 | ||
91f0ebf7 | 794 | static struct ccid_operations ccid2 = { |
3dd9a7c3 | 795 | .ccid_id = DCCPC_CCID2, |
2a91aa39 AB |
796 | .ccid_name = "ccid2", |
797 | .ccid_owner = THIS_MODULE, | |
91f0ebf7 | 798 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), |
2a91aa39 AB |
799 | .ccid_hc_tx_init = ccid2_hc_tx_init, |
800 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, | |
801 | .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, | |
802 | .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, | |
803 | .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, | |
91f0ebf7 | 804 | .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), |
2a91aa39 AB |
805 | .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, |
806 | }; | |
807 | ||
84116716 | 808 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
042d18f9 | 809 | module_param(ccid2_debug, bool, 0444); |
2a91aa39 | 810 | MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); |
84116716 | 811 | #endif |
2a91aa39 AB |
812 | |
813 | static __init int ccid2_module_init(void) | |
814 | { | |
815 | return ccid_register(&ccid2); | |
816 | } | |
817 | module_init(ccid2_module_init); | |
818 | ||
819 | static __exit void ccid2_module_exit(void) | |
820 | { | |
821 | ccid_unregister(&ccid2); | |
822 | } | |
823 | module_exit(ccid2_module_exit); | |
824 | ||
825 | MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); | |
c0c736db | 826 | MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); |
2a91aa39 AB |
827 | MODULE_LICENSE("GPL"); |
828 | MODULE_ALIAS("net-dccp-ccid-2"); |