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 | * BUGS: | |
29 | * - sequence number wrapping | |
2a91aa39 AB |
30 | */ |
31 | ||
2a91aa39 AB |
32 | #include "../ccid.h" |
33 | #include "../dccp.h" | |
34 | #include "ccid2.h" | |
35 | ||
2a91aa39 | 36 | |
8d424f6c | 37 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
84116716 GR |
38 | static int ccid2_debug; |
39 | #define ccid2_pr_debug(format, a...) DCCP_PR_DEBUG(ccid2_debug, format, ##a) | |
2a91aa39 | 40 | |
2a91aa39 AB |
41 | static void ccid2_hc_tx_check_sanity(const struct ccid2_hc_tx_sock *hctx) |
42 | { | |
43 | int len = 0; | |
2a91aa39 | 44 | int pipe = 0; |
c0c736db | 45 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqh; |
2a91aa39 AB |
46 | |
47 | /* there is data in the chain */ | |
48 | if (seqp != hctx->ccid2hctx_seqt) { | |
49 | seqp = seqp->ccid2s_prev; | |
50 | len++; | |
51 | if (!seqp->ccid2s_acked) | |
52 | pipe++; | |
53 | ||
54 | while (seqp != hctx->ccid2hctx_seqt) { | |
c0c736db | 55 | struct ccid2_seq *prev = seqp->ccid2s_prev; |
2a91aa39 | 56 | |
2a91aa39 AB |
57 | len++; |
58 | if (!prev->ccid2s_acked) | |
59 | pipe++; | |
60 | ||
61 | /* packets are sent sequentially */ | |
62 | BUG_ON(seqp->ccid2s_seq <= prev->ccid2s_seq); | |
29651cda AB |
63 | BUG_ON(time_before(seqp->ccid2s_sent, |
64 | prev->ccid2s_sent)); | |
2a91aa39 AB |
65 | |
66 | seqp = prev; | |
67 | } | |
68 | } | |
69 | ||
70 | BUG_ON(pipe != hctx->ccid2hctx_pipe); | |
71 | ccid2_pr_debug("len of chain=%d\n", len); | |
72 | ||
73 | do { | |
74 | seqp = seqp->ccid2s_prev; | |
75 | len++; | |
c0c736db | 76 | } while (seqp != hctx->ccid2hctx_seqh); |
2a91aa39 | 77 | |
2a91aa39 | 78 | ccid2_pr_debug("total len=%d\n", len); |
07978aab | 79 | BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN); |
2a91aa39 AB |
80 | } |
81 | #else | |
84116716 GR |
82 | #define ccid2_pr_debug(format, a...) |
83 | #define ccid2_hc_tx_check_sanity(hctx) | |
2a91aa39 AB |
84 | #endif |
85 | ||
07978aab AB |
86 | static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx, int num, |
87 | gfp_t gfp) | |
88 | { | |
89 | struct ccid2_seq *seqp; | |
90 | int i; | |
91 | ||
92 | /* check if we have space to preserve the pointer to the buffer */ | |
93 | if (hctx->ccid2hctx_seqbufc >= (sizeof(hctx->ccid2hctx_seqbuf) / | |
94 | sizeof(struct ccid2_seq*))) | |
95 | return -ENOMEM; | |
96 | ||
97 | /* allocate buffer and initialize linked list */ | |
98 | seqp = kmalloc(sizeof(*seqp) * num, gfp); | |
99 | if (seqp == NULL) | |
100 | return -ENOMEM; | |
101 | ||
102 | for (i = 0; i < (num - 1); i++) { | |
103 | seqp[i].ccid2s_next = &seqp[i + 1]; | |
104 | seqp[i + 1].ccid2s_prev = &seqp[i]; | |
105 | } | |
106 | seqp[num - 1].ccid2s_next = seqp; | |
107 | seqp->ccid2s_prev = &seqp[num - 1]; | |
108 | ||
109 | /* This is the first allocation. Initiate the head and tail. */ | |
110 | if (hctx->ccid2hctx_seqbufc == 0) | |
111 | hctx->ccid2hctx_seqh = hctx->ccid2hctx_seqt = seqp; | |
112 | else { | |
113 | /* link the existing list with the one we just created */ | |
114 | hctx->ccid2hctx_seqh->ccid2s_next = seqp; | |
115 | seqp->ccid2s_prev = hctx->ccid2hctx_seqh; | |
116 | ||
117 | hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[num - 1]; | |
118 | seqp[num - 1].ccid2s_next = hctx->ccid2hctx_seqt; | |
119 | } | |
120 | ||
121 | /* store the original pointer to the buffer so we can free it */ | |
122 | hctx->ccid2hctx_seqbuf[hctx->ccid2hctx_seqbufc] = seqp; | |
123 | hctx->ccid2hctx_seqbufc++; | |
124 | ||
125 | return 0; | |
126 | } | |
127 | ||
6b57c93d | 128 | static int ccid2_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb) |
2a91aa39 AB |
129 | { |
130 | struct ccid2_hc_tx_sock *hctx; | |
131 | ||
132 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
133 | case 0: /* XXX data packets from userland come through like this */ | |
134 | case DCCP_PKT_DATA: | |
135 | case DCCP_PKT_DATAACK: | |
136 | break; | |
137 | /* No congestion control on other packets */ | |
138 | default: | |
139 | return 0; | |
140 | } | |
141 | ||
c9eaf173 | 142 | hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
143 | |
144 | ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe, | |
145 | hctx->ccid2hctx_cwnd); | |
146 | ||
147 | if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { | |
148 | /* OK we can send... make sure previous packet was sent off */ | |
149 | if (!hctx->ccid2hctx_sendwait) { | |
150 | hctx->ccid2hctx_sendwait = 1; | |
151 | return 0; | |
152 | } | |
153 | } | |
154 | ||
446dec30 | 155 | return 1; /* XXX CCID should dequeue when ready instead of polling */ |
2a91aa39 AB |
156 | } |
157 | ||
158 | static void ccid2_change_l_ack_ratio(struct sock *sk, int val) | |
159 | { | |
160 | struct dccp_sock *dp = dccp_sk(sk); | |
161 | /* | |
162 | * XXX I don't really agree with val != 2. If cwnd is 1, ack ratio | |
163 | * should be 1... it shouldn't be allowed to become 2. | |
164 | * -sorbo. | |
165 | */ | |
166 | if (val != 2) { | |
c0c736db | 167 | const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
168 | int max = hctx->ccid2hctx_cwnd / 2; |
169 | ||
170 | /* round up */ | |
171 | if (hctx->ccid2hctx_cwnd & 1) | |
172 | max++; | |
173 | ||
174 | if (val > max) | |
175 | val = max; | |
176 | } | |
177 | ||
178 | ccid2_pr_debug("changing local ack ratio to %d\n", val); | |
179 | WARN_ON(val <= 0); | |
180 | dp->dccps_l_ack_ratio = val; | |
181 | } | |
182 | ||
374bcf32 | 183 | static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, int val) |
2a91aa39 | 184 | { |
2a91aa39 AB |
185 | if (val == 0) |
186 | val = 1; | |
187 | ||
188 | /* XXX do we need to change ack ratio? */ | |
189 | ccid2_pr_debug("change cwnd to %d\n", val); | |
190 | ||
191 | BUG_ON(val < 1); | |
192 | hctx->ccid2hctx_cwnd = val; | |
193 | } | |
194 | ||
593f16aa AB |
195 | static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) |
196 | { | |
197 | ccid2_pr_debug("change SRTT to %ld\n", val); | |
198 | hctx->ccid2hctx_srtt = val; | |
199 | } | |
200 | ||
201 | static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val) | |
202 | { | |
203 | hctx->ccid2hctx_pipe = val; | |
204 | } | |
205 | ||
2a91aa39 AB |
206 | static void ccid2_start_rto_timer(struct sock *sk); |
207 | ||
208 | static void ccid2_hc_tx_rto_expire(unsigned long data) | |
209 | { | |
210 | struct sock *sk = (struct sock *)data; | |
211 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
212 | long s; | |
213 | ||
2a91aa39 AB |
214 | bh_lock_sock(sk); |
215 | if (sock_owned_by_user(sk)) { | |
216 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
217 | jiffies + HZ / 5); | |
218 | goto out; | |
219 | } | |
220 | ||
221 | ccid2_pr_debug("RTO_EXPIRE\n"); | |
222 | ||
223 | ccid2_hc_tx_check_sanity(hctx); | |
224 | ||
225 | /* back-off timer */ | |
226 | hctx->ccid2hctx_rto <<= 1; | |
227 | ||
228 | s = hctx->ccid2hctx_rto / HZ; | |
229 | if (s > 60) | |
230 | hctx->ccid2hctx_rto = 60 * HZ; | |
231 | ||
232 | ccid2_start_rto_timer(sk); | |
233 | ||
234 | /* adjust pipe, cwnd etc */ | |
593f16aa | 235 | ccid2_change_pipe(hctx, 0); |
2a91aa39 AB |
236 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
237 | if (hctx->ccid2hctx_ssthresh < 2) | |
238 | hctx->ccid2hctx_ssthresh = 2; | |
374bcf32 | 239 | ccid2_change_cwnd(hctx, 1); |
2a91aa39 AB |
240 | |
241 | /* clear state about stuff we sent */ | |
242 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; | |
243 | hctx->ccid2hctx_ssacks = 0; | |
244 | hctx->ccid2hctx_acks = 0; | |
245 | hctx->ccid2hctx_sent = 0; | |
246 | ||
247 | /* clear ack ratio state. */ | |
248 | hctx->ccid2hctx_arsent = 0; | |
249 | hctx->ccid2hctx_ackloss = 0; | |
250 | hctx->ccid2hctx_rpseq = 0; | |
251 | hctx->ccid2hctx_rpdupack = -1; | |
252 | ccid2_change_l_ack_ratio(sk, 1); | |
253 | ccid2_hc_tx_check_sanity(hctx); | |
254 | out: | |
255 | bh_unlock_sock(sk); | |
77ff72d5 | 256 | sock_put(sk); |
2a91aa39 AB |
257 | } |
258 | ||
259 | static void ccid2_start_rto_timer(struct sock *sk) | |
260 | { | |
261 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
262 | ||
263 | ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); | |
264 | ||
265 | BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); | |
266 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
267 | jiffies + hctx->ccid2hctx_rto); | |
268 | } | |
269 | ||
6b57c93d | 270 | static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) |
2a91aa39 AB |
271 | { |
272 | struct dccp_sock *dp = dccp_sk(sk); | |
273 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
07978aab | 274 | struct ccid2_seq *next; |
2a91aa39 AB |
275 | u64 seq; |
276 | ||
277 | ccid2_hc_tx_check_sanity(hctx); | |
278 | ||
279 | BUG_ON(!hctx->ccid2hctx_sendwait); | |
280 | hctx->ccid2hctx_sendwait = 0; | |
593f16aa | 281 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1); |
2a91aa39 AB |
282 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
283 | ||
284 | /* There is an issue. What if another packet is sent between | |
285 | * packet_send() and packet_sent(). Then the sequence number would be | |
286 | * wrong. | |
287 | * -sorbo. | |
288 | */ | |
289 | seq = dp->dccps_gss; | |
290 | ||
291 | hctx->ccid2hctx_seqh->ccid2s_seq = seq; | |
292 | hctx->ccid2hctx_seqh->ccid2s_acked = 0; | |
293 | hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; | |
2a91aa39 | 294 | |
07978aab AB |
295 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
296 | /* check if we need to alloc more space */ | |
297 | if (next == hctx->ccid2hctx_seqt) { | |
298 | int rc; | |
2a91aa39 | 299 | |
07978aab | 300 | ccid2_pr_debug("allocating more space in history\n"); |
39dad26c | 301 | rc = ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, gfp_any()); |
07978aab AB |
302 | BUG_ON(rc); /* XXX what do we do? */ |
303 | ||
304 | next = hctx->ccid2hctx_seqh->ccid2s_next; | |
305 | BUG_ON(next == hctx->ccid2hctx_seqt); | |
2a91aa39 | 306 | } |
07978aab AB |
307 | hctx->ccid2hctx_seqh = next; |
308 | ||
309 | ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, | |
310 | hctx->ccid2hctx_pipe); | |
2a91aa39 AB |
311 | |
312 | hctx->ccid2hctx_sent++; | |
313 | ||
314 | /* Ack Ratio. Need to maintain a concept of how many windows we sent */ | |
315 | hctx->ccid2hctx_arsent++; | |
316 | /* We had an ack loss in this window... */ | |
317 | if (hctx->ccid2hctx_ackloss) { | |
318 | if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { | |
c0c736db ACM |
319 | hctx->ccid2hctx_arsent = 0; |
320 | hctx->ccid2hctx_ackloss = 0; | |
2a91aa39 | 321 | } |
c0c736db ACM |
322 | } else { |
323 | /* No acks lost up to now... */ | |
2a91aa39 AB |
324 | /* decrease ack ratio if enough packets were sent */ |
325 | if (dp->dccps_l_ack_ratio > 1) { | |
326 | /* XXX don't calculate denominator each time */ | |
c0c736db ACM |
327 | int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - |
328 | dp->dccps_l_ack_ratio; | |
2a91aa39 | 329 | |
2a91aa39 AB |
330 | denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; |
331 | ||
332 | if (hctx->ccid2hctx_arsent >= denom) { | |
333 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); | |
334 | hctx->ccid2hctx_arsent = 0; | |
335 | } | |
c0c736db ACM |
336 | } else { |
337 | /* we can't increase ack ratio further [1] */ | |
2a91aa39 AB |
338 | hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ |
339 | } | |
340 | } | |
341 | ||
342 | /* setup RTO timer */ | |
c0c736db | 343 | if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
2a91aa39 | 344 | ccid2_start_rto_timer(sk); |
c0c736db | 345 | |
8d424f6c | 346 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
2a91aa39 | 347 | ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
234af484 | 348 | ccid2_pr_debug("Sent: seq=%llu\n", (unsigned long long)seq); |
2a91aa39 AB |
349 | do { |
350 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; | |
351 | ||
352 | while (seqp != hctx->ccid2hctx_seqh) { | |
353 | ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", | |
8109b02b | 354 | (unsigned long long)seqp->ccid2s_seq, |
234af484 | 355 | seqp->ccid2s_acked, seqp->ccid2s_sent); |
2a91aa39 AB |
356 | seqp = seqp->ccid2s_next; |
357 | } | |
c0c736db | 358 | } while (0); |
2a91aa39 AB |
359 | ccid2_pr_debug("=========\n"); |
360 | ccid2_hc_tx_check_sanity(hctx); | |
361 | #endif | |
362 | } | |
363 | ||
364 | /* XXX Lame code duplication! | |
365 | * returns -1 if none was found. | |
366 | * else returns the next offset to use in the function call. | |
367 | */ | |
368 | static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, | |
369 | unsigned char **vec, unsigned char *veclen) | |
370 | { | |
c9eaf173 YH |
371 | const struct dccp_hdr *dh = dccp_hdr(skb); |
372 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
373 | unsigned char *opt_ptr; | |
374 | const unsigned char *opt_end = (unsigned char *)dh + | |
375 | (dh->dccph_doff * 4); | |
376 | unsigned char opt, len; | |
377 | unsigned char *value; | |
2a91aa39 AB |
378 | |
379 | BUG_ON(offset < 0); | |
380 | options += offset; | |
381 | opt_ptr = options; | |
382 | if (opt_ptr >= opt_end) | |
383 | return -1; | |
384 | ||
385 | while (opt_ptr != opt_end) { | |
c9eaf173 YH |
386 | opt = *opt_ptr++; |
387 | len = 0; | |
388 | value = NULL; | |
389 | ||
390 | /* Check if this isn't a single byte option */ | |
391 | if (opt > DCCPO_MAX_RESERVED) { | |
392 | if (opt_ptr == opt_end) | |
393 | goto out_invalid_option; | |
394 | ||
395 | len = *opt_ptr++; | |
396 | if (len < 3) | |
397 | goto out_invalid_option; | |
398 | /* | |
399 | * Remove the type and len fields, leaving | |
400 | * just the value size | |
401 | */ | |
402 | len -= 2; | |
403 | value = opt_ptr; | |
404 | opt_ptr += len; | |
405 | ||
406 | if (opt_ptr > opt_end) | |
407 | goto out_invalid_option; | |
408 | } | |
2a91aa39 AB |
409 | |
410 | switch (opt) { | |
411 | case DCCPO_ACK_VECTOR_0: | |
412 | case DCCPO_ACK_VECTOR_1: | |
413 | *vec = value; | |
414 | *veclen = len; | |
415 | return offset + (opt_ptr - options); | |
2a91aa39 AB |
416 | } |
417 | } | |
418 | ||
419 | return -1; | |
420 | ||
421 | out_invalid_option: | |
59348b19 | 422 | DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); |
2a91aa39 AB |
423 | return -1; |
424 | } | |
425 | ||
77ff72d5 | 426 | static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) |
2a91aa39 | 427 | { |
77ff72d5 AB |
428 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
429 | ||
430 | sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); | |
431 | ccid2_pr_debug("deleted RTO timer\n"); | |
2a91aa39 AB |
432 | } |
433 | ||
434 | static inline void ccid2_new_ack(struct sock *sk, | |
c9eaf173 | 435 | struct ccid2_seq *seqp, |
2a91aa39 AB |
436 | unsigned int *maxincr) |
437 | { | |
438 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
439 | ||
440 | /* slow start */ | |
441 | if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { | |
442 | hctx->ccid2hctx_acks = 0; | |
443 | ||
444 | /* We can increase cwnd at most maxincr [ack_ratio/2] */ | |
445 | if (*maxincr) { | |
446 | /* increase every 2 acks */ | |
447 | hctx->ccid2hctx_ssacks++; | |
448 | if (hctx->ccid2hctx_ssacks == 2) { | |
374bcf32 | 449 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd+1); |
2a91aa39 AB |
450 | hctx->ccid2hctx_ssacks = 0; |
451 | *maxincr = *maxincr - 1; | |
452 | } | |
c0c736db ACM |
453 | } else { |
454 | /* increased cwnd enough for this single ack */ | |
2a91aa39 AB |
455 | hctx->ccid2hctx_ssacks = 0; |
456 | } | |
c0c736db | 457 | } else { |
2a91aa39 AB |
458 | hctx->ccid2hctx_ssacks = 0; |
459 | hctx->ccid2hctx_acks++; | |
460 | ||
461 | if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { | |
374bcf32 | 462 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd + 1); |
2a91aa39 AB |
463 | hctx->ccid2hctx_acks = 0; |
464 | } | |
465 | } | |
466 | ||
467 | /* update RTO */ | |
468 | if (hctx->ccid2hctx_srtt == -1 || | |
29651cda AB |
469 | time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { |
470 | unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; | |
2a91aa39 AB |
471 | int s; |
472 | ||
473 | /* first measurement */ | |
474 | if (hctx->ccid2hctx_srtt == -1) { | |
475 | ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", | |
8109b02b | 476 | r, jiffies, |
234af484 | 477 | (unsigned long long)seqp->ccid2s_seq); |
593f16aa | 478 | ccid2_change_srtt(hctx, r); |
2a91aa39 | 479 | hctx->ccid2hctx_rttvar = r >> 1; |
c0c736db | 480 | } else { |
2a91aa39 AB |
481 | /* RTTVAR */ |
482 | long tmp = hctx->ccid2hctx_srtt - r; | |
593f16aa AB |
483 | long srtt; |
484 | ||
2a91aa39 AB |
485 | if (tmp < 0) |
486 | tmp *= -1; | |
487 | ||
488 | tmp >>= 2; | |
489 | hctx->ccid2hctx_rttvar *= 3; | |
490 | hctx->ccid2hctx_rttvar >>= 2; | |
491 | hctx->ccid2hctx_rttvar += tmp; | |
492 | ||
493 | /* SRTT */ | |
593f16aa AB |
494 | srtt = hctx->ccid2hctx_srtt; |
495 | srtt *= 7; | |
496 | srtt >>= 3; | |
2a91aa39 | 497 | tmp = r >> 3; |
593f16aa AB |
498 | srtt += tmp; |
499 | ccid2_change_srtt(hctx, srtt); | |
2a91aa39 AB |
500 | } |
501 | s = hctx->ccid2hctx_rttvar << 2; | |
502 | /* clock granularity is 1 when based on jiffies */ | |
503 | if (!s) | |
504 | s = 1; | |
505 | hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; | |
506 | ||
507 | /* must be at least a second */ | |
508 | s = hctx->ccid2hctx_rto / HZ; | |
509 | /* DCCP doesn't require this [but I like it cuz my code sux] */ | |
510 | #if 1 | |
511 | if (s < 1) | |
512 | hctx->ccid2hctx_rto = HZ; | |
513 | #endif | |
514 | /* max 60 seconds */ | |
515 | if (s > 60) | |
516 | hctx->ccid2hctx_rto = HZ * 60; | |
517 | ||
518 | hctx->ccid2hctx_lastrtt = jiffies; | |
519 | ||
520 | ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", | |
8109b02b ACM |
521 | hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, |
522 | hctx->ccid2hctx_rto, HZ, r); | |
2a91aa39 AB |
523 | hctx->ccid2hctx_sent = 0; |
524 | } | |
525 | ||
526 | /* we got a new ack, so re-start RTO timer */ | |
77ff72d5 | 527 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
528 | ccid2_start_rto_timer(sk); |
529 | } | |
530 | ||
77ff72d5 | 531 | static void ccid2_hc_tx_dec_pipe(struct sock *sk) |
2a91aa39 | 532 | { |
77ff72d5 AB |
533 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
534 | ||
593f16aa | 535 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1); |
2a91aa39 AB |
536 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
537 | ||
538 | if (hctx->ccid2hctx_pipe == 0) | |
77ff72d5 | 539 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
540 | } |
541 | ||
374bcf32 AB |
542 | static void ccid2_congestion_event(struct ccid2_hc_tx_sock *hctx, |
543 | struct ccid2_seq *seqp) | |
544 | { | |
545 | if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { | |
546 | ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); | |
547 | return; | |
548 | } | |
549 | ||
550 | hctx->ccid2hctx_last_cong = jiffies; | |
551 | ||
552 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1); | |
553 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; | |
554 | if (hctx->ccid2hctx_ssthresh < 2) | |
555 | hctx->ccid2hctx_ssthresh = 2; | |
556 | } | |
557 | ||
2a91aa39 AB |
558 | static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |
559 | { | |
560 | struct dccp_sock *dp = dccp_sk(sk); | |
561 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
562 | u64 ackno, seqno; | |
563 | struct ccid2_seq *seqp; | |
564 | unsigned char *vector; | |
565 | unsigned char veclen; | |
566 | int offset = 0; | |
567 | int done = 0; | |
2a91aa39 AB |
568 | unsigned int maxincr = 0; |
569 | ||
570 | ccid2_hc_tx_check_sanity(hctx); | |
571 | /* check reverse path congestion */ | |
572 | seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
573 | ||
574 | /* XXX this whole "algorithm" is broken. Need to fix it to keep track | |
575 | * of the seqnos of the dupacks so that rpseq and rpdupack are correct | |
576 | * -sorbo. | |
577 | */ | |
578 | /* need to bootstrap */ | |
579 | if (hctx->ccid2hctx_rpdupack == -1) { | |
580 | hctx->ccid2hctx_rpdupack = 0; | |
581 | hctx->ccid2hctx_rpseq = seqno; | |
c0c736db | 582 | } else { |
2a91aa39 | 583 | /* check if packet is consecutive */ |
c0c736db | 584 | if ((hctx->ccid2hctx_rpseq + 1) == seqno) |
2a91aa39 | 585 | hctx->ccid2hctx_rpseq++; |
2a91aa39 AB |
586 | /* it's a later packet */ |
587 | else if (after48(seqno, hctx->ccid2hctx_rpseq)) { | |
588 | hctx->ccid2hctx_rpdupack++; | |
589 | ||
590 | /* check if we got enough dupacks */ | |
591 | if (hctx->ccid2hctx_rpdupack >= | |
592 | hctx->ccid2hctx_numdupack) { | |
2a91aa39 AB |
593 | hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
594 | hctx->ccid2hctx_rpseq = 0; | |
595 | ||
596 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1); | |
597 | } | |
598 | } | |
599 | } | |
600 | ||
601 | /* check forward path congestion */ | |
602 | /* still didn't send out new data packets */ | |
603 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) | |
604 | return; | |
605 | ||
606 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
607 | case DCCP_PKT_ACK: | |
608 | case DCCP_PKT_DATAACK: | |
609 | break; | |
2a91aa39 AB |
610 | default: |
611 | return; | |
612 | } | |
613 | ||
614 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
32aac18d AB |
615 | if (after48(ackno, hctx->ccid2hctx_high_ack)) |
616 | hctx->ccid2hctx_high_ack = ackno; | |
617 | ||
618 | seqp = hctx->ccid2hctx_seqt; | |
619 | while (before48(seqp->ccid2s_seq, ackno)) { | |
620 | seqp = seqp->ccid2s_next; | |
621 | if (seqp == hctx->ccid2hctx_seqh) { | |
622 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
623 | break; | |
624 | } | |
625 | } | |
2a91aa39 AB |
626 | |
627 | /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for | |
628 | * this single ack. I round up. | |
629 | * -sorbo. | |
630 | */ | |
631 | maxincr = dp->dccps_l_ack_ratio >> 1; | |
632 | maxincr++; | |
633 | ||
634 | /* go through all ack vectors */ | |
635 | while ((offset = ccid2_ackvector(sk, skb, offset, | |
636 | &vector, &veclen)) != -1) { | |
637 | /* go through this ack vector */ | |
638 | while (veclen--) { | |
639 | const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; | |
640 | u64 ackno_end_rl; | |
641 | ||
642 | dccp_set_seqno(&ackno_end_rl, ackno - rl); | |
234af484 RD |
643 | ccid2_pr_debug("ackvec start:%llu end:%llu\n", |
644 | (unsigned long long)ackno, | |
645 | (unsigned long long)ackno_end_rl); | |
2a91aa39 AB |
646 | /* if the seqno we are analyzing is larger than the |
647 | * current ackno, then move towards the tail of our | |
648 | * seqnos. | |
649 | */ | |
650 | while (after48(seqp->ccid2s_seq, ackno)) { | |
651 | if (seqp == hctx->ccid2hctx_seqt) { | |
652 | done = 1; | |
653 | break; | |
654 | } | |
655 | seqp = seqp->ccid2s_prev; | |
656 | } | |
657 | if (done) | |
658 | break; | |
659 | ||
660 | /* check all seqnos in the range of the vector | |
661 | * run length | |
662 | */ | |
663 | while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { | |
8e27e465 AB |
664 | const u8 state = *vector & |
665 | DCCP_ACKVEC_STATE_MASK; | |
2a91aa39 AB |
666 | |
667 | /* new packet received or marked */ | |
668 | if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && | |
669 | !seqp->ccid2s_acked) { | |
8109b02b | 670 | if (state == |
2a91aa39 | 671 | DCCP_ACKVEC_STATE_ECN_MARKED) { |
8109b02b | 672 | ccid2_congestion_event(hctx, |
374bcf32 | 673 | seqp); |
c0c736db | 674 | } else |
2a91aa39 AB |
675 | ccid2_new_ack(sk, seqp, |
676 | &maxincr); | |
2a91aa39 AB |
677 | |
678 | seqp->ccid2s_acked = 1; | |
679 | ccid2_pr_debug("Got ack for %llu\n", | |
234af484 | 680 | (unsigned long long)seqp->ccid2s_seq); |
77ff72d5 | 681 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
682 | } |
683 | if (seqp == hctx->ccid2hctx_seqt) { | |
684 | done = 1; | |
685 | break; | |
686 | } | |
687 | seqp = seqp->ccid2s_next; | |
688 | } | |
689 | if (done) | |
690 | break; | |
691 | ||
692 | ||
693 | dccp_set_seqno(&ackno, ackno_end_rl - 1); | |
694 | vector++; | |
695 | } | |
696 | if (done) | |
697 | break; | |
698 | } | |
699 | ||
700 | /* The state about what is acked should be correct now | |
701 | * Check for NUMDUPACK | |
702 | */ | |
32aac18d AB |
703 | seqp = hctx->ccid2hctx_seqt; |
704 | while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { | |
705 | seqp = seqp->ccid2s_next; | |
706 | if (seqp == hctx->ccid2hctx_seqh) { | |
707 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
708 | break; | |
709 | } | |
710 | } | |
2a91aa39 AB |
711 | done = 0; |
712 | while (1) { | |
713 | if (seqp->ccid2s_acked) { | |
714 | done++; | |
c0c736db | 715 | if (done == hctx->ccid2hctx_numdupack) |
2a91aa39 | 716 | break; |
2a91aa39 | 717 | } |
c0c736db | 718 | if (seqp == hctx->ccid2hctx_seqt) |
2a91aa39 | 719 | break; |
2a91aa39 AB |
720 | seqp = seqp->ccid2s_prev; |
721 | } | |
722 | ||
723 | /* If there are at least 3 acknowledgements, anything unacknowledged | |
724 | * below the last sequence number is considered lost | |
725 | */ | |
726 | if (done == hctx->ccid2hctx_numdupack) { | |
727 | struct ccid2_seq *last_acked = seqp; | |
728 | ||
729 | /* check for lost packets */ | |
730 | while (1) { | |
731 | if (!seqp->ccid2s_acked) { | |
374bcf32 | 732 | ccid2_pr_debug("Packet lost: %llu\n", |
234af484 | 733 | (unsigned long long)seqp->ccid2s_seq); |
374bcf32 AB |
734 | /* XXX need to traverse from tail -> head in |
735 | * order to detect multiple congestion events in | |
736 | * one ack vector. | |
737 | */ | |
738 | ccid2_congestion_event(hctx, seqp); | |
77ff72d5 | 739 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
740 | } |
741 | if (seqp == hctx->ccid2hctx_seqt) | |
742 | break; | |
743 | seqp = seqp->ccid2s_prev; | |
744 | } | |
745 | ||
746 | hctx->ccid2hctx_seqt = last_acked; | |
747 | } | |
748 | ||
749 | /* trim acked packets in tail */ | |
750 | while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { | |
751 | if (!hctx->ccid2hctx_seqt->ccid2s_acked) | |
752 | break; | |
753 | ||
754 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; | |
755 | } | |
756 | ||
2a91aa39 AB |
757 | ccid2_hc_tx_check_sanity(hctx); |
758 | } | |
759 | ||
91f0ebf7 | 760 | static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) |
2a91aa39 | 761 | { |
c9eaf173 | 762 | struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); |
2a91aa39 | 763 | |
374bcf32 | 764 | ccid2_change_cwnd(hctx, 1); |
d458c25c AB |
765 | /* Initialize ssthresh to infinity. This means that we will exit the |
766 | * initial slow-start after the first packet loss. This is what we | |
767 | * want. | |
768 | */ | |
769 | hctx->ccid2hctx_ssthresh = ~0; | |
2a91aa39 | 770 | hctx->ccid2hctx_numdupack = 3; |
07978aab | 771 | hctx->ccid2hctx_seqbufc = 0; |
2a91aa39 AB |
772 | |
773 | /* XXX init ~ to window size... */ | |
07978aab | 774 | if (ccid2_hc_tx_alloc_seq(hctx, CCID2_SEQBUF_LEN, GFP_ATOMIC) != 0) |
2a91aa39 | 775 | return -ENOMEM; |
91f0ebf7 | 776 | |
2a91aa39 AB |
777 | hctx->ccid2hctx_sent = 0; |
778 | hctx->ccid2hctx_rto = 3 * HZ; | |
593f16aa | 779 | ccid2_change_srtt(hctx, -1); |
2a91aa39 AB |
780 | hctx->ccid2hctx_rttvar = -1; |
781 | hctx->ccid2hctx_lastrtt = 0; | |
782 | hctx->ccid2hctx_rpdupack = -1; | |
374bcf32 | 783 | hctx->ccid2hctx_last_cong = jiffies; |
32aac18d | 784 | hctx->ccid2hctx_high_ack = 0; |
2a91aa39 AB |
785 | |
786 | hctx->ccid2hctx_rtotimer.function = &ccid2_hc_tx_rto_expire; | |
787 | hctx->ccid2hctx_rtotimer.data = (unsigned long)sk; | |
788 | init_timer(&hctx->ccid2hctx_rtotimer); | |
789 | ||
790 | ccid2_hc_tx_check_sanity(hctx); | |
791 | return 0; | |
792 | } | |
793 | ||
794 | static void ccid2_hc_tx_exit(struct sock *sk) | |
795 | { | |
c9eaf173 | 796 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
07978aab | 797 | int i; |
2a91aa39 | 798 | |
77ff72d5 | 799 | ccid2_hc_tx_kill_rto_timer(sk); |
07978aab AB |
800 | |
801 | for (i = 0; i < hctx->ccid2hctx_seqbufc; i++) | |
802 | kfree(hctx->ccid2hctx_seqbuf[i]); | |
803 | hctx->ccid2hctx_seqbufc = 0; | |
2a91aa39 AB |
804 | } |
805 | ||
806 | static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
807 | { | |
808 | const struct dccp_sock *dp = dccp_sk(sk); | |
809 | struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk); | |
810 | ||
811 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
812 | case DCCP_PKT_DATA: | |
813 | case DCCP_PKT_DATAACK: | |
814 | hcrx->ccid2hcrx_data++; | |
815 | if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { | |
816 | dccp_send_ack(sk); | |
817 | hcrx->ccid2hcrx_data = 0; | |
818 | } | |
819 | break; | |
820 | } | |
821 | } | |
822 | ||
91f0ebf7 | 823 | static struct ccid_operations ccid2 = { |
3dd9a7c3 | 824 | .ccid_id = DCCPC_CCID2, |
2a91aa39 AB |
825 | .ccid_name = "ccid2", |
826 | .ccid_owner = THIS_MODULE, | |
91f0ebf7 | 827 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), |
2a91aa39 AB |
828 | .ccid_hc_tx_init = ccid2_hc_tx_init, |
829 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, | |
830 | .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, | |
831 | .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, | |
832 | .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, | |
91f0ebf7 | 833 | .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), |
2a91aa39 AB |
834 | .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, |
835 | }; | |
836 | ||
84116716 | 837 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
042d18f9 | 838 | module_param(ccid2_debug, bool, 0444); |
2a91aa39 | 839 | MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); |
84116716 | 840 | #endif |
2a91aa39 AB |
841 | |
842 | static __init int ccid2_module_init(void) | |
843 | { | |
844 | return ccid_register(&ccid2); | |
845 | } | |
846 | module_init(ccid2_module_init); | |
847 | ||
848 | static __exit void ccid2_module_exit(void) | |
849 | { | |
850 | ccid_unregister(&ccid2); | |
851 | } | |
852 | module_exit(ccid2_module_exit); | |
853 | ||
854 | MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); | |
c0c736db | 855 | MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); |
2a91aa39 AB |
856 | MODULE_LICENSE("GPL"); |
857 | MODULE_ALIAS("net-dccp-ccid-2"); |