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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 */ | |
5e28599a GR |
62 | BUG_ON(dccp_delta_seqno(seqp->ccid2s_seq, |
63 | prev->ccid2s_seq ) >= 0); | |
29651cda AB |
64 | BUG_ON(time_before(seqp->ccid2s_sent, |
65 | prev->ccid2s_sent)); | |
2a91aa39 AB |
66 | |
67 | seqp = prev; | |
68 | } | |
69 | } | |
70 | ||
71 | BUG_ON(pipe != hctx->ccid2hctx_pipe); | |
72 | ccid2_pr_debug("len of chain=%d\n", len); | |
73 | ||
74 | do { | |
75 | seqp = seqp->ccid2s_prev; | |
76 | len++; | |
c0c736db | 77 | } while (seqp != hctx->ccid2hctx_seqh); |
2a91aa39 | 78 | |
2a91aa39 | 79 | ccid2_pr_debug("total len=%d\n", len); |
07978aab | 80 | BUG_ON(len != hctx->ccid2hctx_seqbufc * CCID2_SEQBUF_LEN); |
2a91aa39 AB |
81 | } |
82 | #else | |
84116716 GR |
83 | #define ccid2_pr_debug(format, a...) |
84 | #define ccid2_hc_tx_check_sanity(hctx) | |
2a91aa39 AB |
85 | #endif |
86 | ||
cd1f7d34 | 87 | static int ccid2_hc_tx_alloc_seq(struct ccid2_hc_tx_sock *hctx) |
07978aab AB |
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 */ | |
cd1f7d34 | 98 | seqp = kmalloc(CCID2_SEQBUF_LEN * sizeof(struct ccid2_seq), gfp_any()); |
07978aab AB |
99 | if (seqp == NULL) |
100 | return -ENOMEM; | |
101 | ||
cd1f7d34 | 102 | for (i = 0; i < (CCID2_SEQBUF_LEN - 1); i++) { |
07978aab AB |
103 | seqp[i].ccid2s_next = &seqp[i + 1]; |
104 | seqp[i + 1].ccid2s_prev = &seqp[i]; | |
105 | } | |
cd1f7d34 GR |
106 | seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = seqp; |
107 | seqp->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; | |
07978aab AB |
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 | ||
cd1f7d34 GR |
117 | hctx->ccid2hctx_seqt->ccid2s_prev = &seqp[CCID2_SEQBUF_LEN - 1]; |
118 | seqp[CCID2_SEQBUF_LEN - 1].ccid2s_next = hctx->ccid2hctx_seqt; | |
07978aab AB |
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 | 129 | { |
6c583248 | 130 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
131 | |
132 | ccid2_pr_debug("pipe=%d cwnd=%d\n", hctx->ccid2hctx_pipe, | |
133 | hctx->ccid2hctx_cwnd); | |
134 | ||
135 | if (hctx->ccid2hctx_pipe < hctx->ccid2hctx_cwnd) { | |
136 | /* OK we can send... make sure previous packet was sent off */ | |
137 | if (!hctx->ccid2hctx_sendwait) { | |
138 | hctx->ccid2hctx_sendwait = 1; | |
139 | return 0; | |
140 | } | |
141 | } | |
142 | ||
446dec30 | 143 | return 1; /* XXX CCID should dequeue when ready instead of polling */ |
2a91aa39 AB |
144 | } |
145 | ||
146 | static void ccid2_change_l_ack_ratio(struct sock *sk, int val) | |
147 | { | |
148 | struct dccp_sock *dp = dccp_sk(sk); | |
149 | /* | |
150 | * XXX I don't really agree with val != 2. If cwnd is 1, ack ratio | |
151 | * should be 1... it shouldn't be allowed to become 2. | |
152 | * -sorbo. | |
153 | */ | |
154 | if (val != 2) { | |
c0c736db | 155 | const struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
2a91aa39 AB |
156 | int max = hctx->ccid2hctx_cwnd / 2; |
157 | ||
158 | /* round up */ | |
159 | if (hctx->ccid2hctx_cwnd & 1) | |
160 | max++; | |
161 | ||
162 | if (val > max) | |
163 | val = max; | |
164 | } | |
165 | ||
166 | ccid2_pr_debug("changing local ack ratio to %d\n", val); | |
167 | WARN_ON(val <= 0); | |
168 | dp->dccps_l_ack_ratio = val; | |
169 | } | |
170 | ||
ee196c21 | 171 | static void ccid2_change_cwnd(struct ccid2_hc_tx_sock *hctx, u32 val) |
2a91aa39 | 172 | { |
2a91aa39 | 173 | /* XXX do we need to change ack ratio? */ |
ee196c21 GR |
174 | hctx->ccid2hctx_cwnd = val? : 1; |
175 | ccid2_pr_debug("changed cwnd to %u\n", hctx->ccid2hctx_cwnd); | |
2a91aa39 AB |
176 | } |
177 | ||
593f16aa AB |
178 | static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) |
179 | { | |
180 | ccid2_pr_debug("change SRTT to %ld\n", val); | |
181 | hctx->ccid2hctx_srtt = val; | |
182 | } | |
183 | ||
184 | static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val) | |
185 | { | |
186 | hctx->ccid2hctx_pipe = val; | |
187 | } | |
188 | ||
2a91aa39 AB |
189 | static void ccid2_start_rto_timer(struct sock *sk); |
190 | ||
191 | static void ccid2_hc_tx_rto_expire(unsigned long data) | |
192 | { | |
193 | struct sock *sk = (struct sock *)data; | |
194 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
195 | long s; | |
196 | ||
2a91aa39 AB |
197 | bh_lock_sock(sk); |
198 | if (sock_owned_by_user(sk)) { | |
199 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
200 | jiffies + HZ / 5); | |
201 | goto out; | |
202 | } | |
203 | ||
204 | ccid2_pr_debug("RTO_EXPIRE\n"); | |
205 | ||
206 | ccid2_hc_tx_check_sanity(hctx); | |
207 | ||
208 | /* back-off timer */ | |
209 | hctx->ccid2hctx_rto <<= 1; | |
210 | ||
211 | s = hctx->ccid2hctx_rto / HZ; | |
212 | if (s > 60) | |
213 | hctx->ccid2hctx_rto = 60 * HZ; | |
214 | ||
215 | ccid2_start_rto_timer(sk); | |
216 | ||
217 | /* adjust pipe, cwnd etc */ | |
593f16aa | 218 | ccid2_change_pipe(hctx, 0); |
2a91aa39 AB |
219 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
220 | if (hctx->ccid2hctx_ssthresh < 2) | |
221 | hctx->ccid2hctx_ssthresh = 2; | |
374bcf32 | 222 | ccid2_change_cwnd(hctx, 1); |
2a91aa39 AB |
223 | |
224 | /* clear state about stuff we sent */ | |
225 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; | |
226 | hctx->ccid2hctx_ssacks = 0; | |
227 | hctx->ccid2hctx_acks = 0; | |
228 | hctx->ccid2hctx_sent = 0; | |
229 | ||
230 | /* clear ack ratio state. */ | |
231 | hctx->ccid2hctx_arsent = 0; | |
232 | hctx->ccid2hctx_ackloss = 0; | |
233 | hctx->ccid2hctx_rpseq = 0; | |
234 | hctx->ccid2hctx_rpdupack = -1; | |
235 | ccid2_change_l_ack_ratio(sk, 1); | |
236 | ccid2_hc_tx_check_sanity(hctx); | |
237 | out: | |
238 | bh_unlock_sock(sk); | |
77ff72d5 | 239 | sock_put(sk); |
2a91aa39 AB |
240 | } |
241 | ||
242 | static void ccid2_start_rto_timer(struct sock *sk) | |
243 | { | |
244 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
245 | ||
246 | ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); | |
247 | ||
248 | BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); | |
249 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
250 | jiffies + hctx->ccid2hctx_rto); | |
251 | } | |
252 | ||
6b57c93d | 253 | static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) |
2a91aa39 AB |
254 | { |
255 | struct dccp_sock *dp = dccp_sk(sk); | |
256 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
07978aab | 257 | struct ccid2_seq *next; |
2a91aa39 AB |
258 | u64 seq; |
259 | ||
260 | ccid2_hc_tx_check_sanity(hctx); | |
261 | ||
262 | BUG_ON(!hctx->ccid2hctx_sendwait); | |
263 | hctx->ccid2hctx_sendwait = 0; | |
593f16aa | 264 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1); |
2a91aa39 AB |
265 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
266 | ||
267 | /* There is an issue. What if another packet is sent between | |
268 | * packet_send() and packet_sent(). Then the sequence number would be | |
269 | * wrong. | |
270 | * -sorbo. | |
271 | */ | |
272 | seq = dp->dccps_gss; | |
273 | ||
274 | hctx->ccid2hctx_seqh->ccid2s_seq = seq; | |
275 | hctx->ccid2hctx_seqh->ccid2s_acked = 0; | |
276 | hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; | |
2a91aa39 | 277 | |
07978aab AB |
278 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
279 | /* check if we need to alloc more space */ | |
280 | if (next == hctx->ccid2hctx_seqt) { | |
7d9e8931 GR |
281 | if (ccid2_hc_tx_alloc_seq(hctx)) { |
282 | DCCP_CRIT("packet history - out of memory!"); | |
283 | /* FIXME: find a more graceful way to bail out */ | |
284 | return; | |
285 | } | |
07978aab AB |
286 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
287 | BUG_ON(next == hctx->ccid2hctx_seqt); | |
2a91aa39 | 288 | } |
07978aab AB |
289 | hctx->ccid2hctx_seqh = next; |
290 | ||
291 | ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, | |
292 | hctx->ccid2hctx_pipe); | |
2a91aa39 AB |
293 | |
294 | hctx->ccid2hctx_sent++; | |
295 | ||
296 | /* Ack Ratio. Need to maintain a concept of how many windows we sent */ | |
297 | hctx->ccid2hctx_arsent++; | |
298 | /* We had an ack loss in this window... */ | |
299 | if (hctx->ccid2hctx_ackloss) { | |
300 | if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { | |
c0c736db ACM |
301 | hctx->ccid2hctx_arsent = 0; |
302 | hctx->ccid2hctx_ackloss = 0; | |
2a91aa39 | 303 | } |
c0c736db ACM |
304 | } else { |
305 | /* No acks lost up to now... */ | |
2a91aa39 AB |
306 | /* decrease ack ratio if enough packets were sent */ |
307 | if (dp->dccps_l_ack_ratio > 1) { | |
308 | /* XXX don't calculate denominator each time */ | |
c0c736db ACM |
309 | int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - |
310 | dp->dccps_l_ack_ratio; | |
2a91aa39 | 311 | |
2a91aa39 AB |
312 | denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; |
313 | ||
314 | if (hctx->ccid2hctx_arsent >= denom) { | |
315 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); | |
316 | hctx->ccid2hctx_arsent = 0; | |
317 | } | |
c0c736db ACM |
318 | } else { |
319 | /* we can't increase ack ratio further [1] */ | |
2a91aa39 AB |
320 | hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ |
321 | } | |
322 | } | |
323 | ||
324 | /* setup RTO timer */ | |
c0c736db | 325 | if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
2a91aa39 | 326 | ccid2_start_rto_timer(sk); |
c0c736db | 327 | |
8d424f6c | 328 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
2a91aa39 | 329 | ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
234af484 | 330 | ccid2_pr_debug("Sent: seq=%llu\n", (unsigned long long)seq); |
2a91aa39 AB |
331 | do { |
332 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; | |
333 | ||
334 | while (seqp != hctx->ccid2hctx_seqh) { | |
335 | ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", | |
8109b02b | 336 | (unsigned long long)seqp->ccid2s_seq, |
234af484 | 337 | seqp->ccid2s_acked, seqp->ccid2s_sent); |
2a91aa39 AB |
338 | seqp = seqp->ccid2s_next; |
339 | } | |
c0c736db | 340 | } while (0); |
2a91aa39 AB |
341 | ccid2_pr_debug("=========\n"); |
342 | ccid2_hc_tx_check_sanity(hctx); | |
343 | #endif | |
344 | } | |
345 | ||
346 | /* XXX Lame code duplication! | |
347 | * returns -1 if none was found. | |
348 | * else returns the next offset to use in the function call. | |
349 | */ | |
350 | static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, | |
351 | unsigned char **vec, unsigned char *veclen) | |
352 | { | |
c9eaf173 YH |
353 | const struct dccp_hdr *dh = dccp_hdr(skb); |
354 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
355 | unsigned char *opt_ptr; | |
356 | const unsigned char *opt_end = (unsigned char *)dh + | |
357 | (dh->dccph_doff * 4); | |
358 | unsigned char opt, len; | |
359 | unsigned char *value; | |
2a91aa39 AB |
360 | |
361 | BUG_ON(offset < 0); | |
362 | options += offset; | |
363 | opt_ptr = options; | |
364 | if (opt_ptr >= opt_end) | |
365 | return -1; | |
366 | ||
367 | while (opt_ptr != opt_end) { | |
c9eaf173 YH |
368 | opt = *opt_ptr++; |
369 | len = 0; | |
370 | value = NULL; | |
371 | ||
372 | /* Check if this isn't a single byte option */ | |
373 | if (opt > DCCPO_MAX_RESERVED) { | |
374 | if (opt_ptr == opt_end) | |
375 | goto out_invalid_option; | |
376 | ||
377 | len = *opt_ptr++; | |
378 | if (len < 3) | |
379 | goto out_invalid_option; | |
380 | /* | |
381 | * Remove the type and len fields, leaving | |
382 | * just the value size | |
383 | */ | |
384 | len -= 2; | |
385 | value = opt_ptr; | |
386 | opt_ptr += len; | |
387 | ||
388 | if (opt_ptr > opt_end) | |
389 | goto out_invalid_option; | |
390 | } | |
2a91aa39 AB |
391 | |
392 | switch (opt) { | |
393 | case DCCPO_ACK_VECTOR_0: | |
394 | case DCCPO_ACK_VECTOR_1: | |
395 | *vec = value; | |
396 | *veclen = len; | |
397 | return offset + (opt_ptr - options); | |
2a91aa39 AB |
398 | } |
399 | } | |
400 | ||
401 | return -1; | |
402 | ||
403 | out_invalid_option: | |
59348b19 | 404 | DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); |
2a91aa39 AB |
405 | return -1; |
406 | } | |
407 | ||
77ff72d5 | 408 | static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) |
2a91aa39 | 409 | { |
77ff72d5 AB |
410 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
411 | ||
412 | sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); | |
413 | ccid2_pr_debug("deleted RTO timer\n"); | |
2a91aa39 AB |
414 | } |
415 | ||
416 | static inline void ccid2_new_ack(struct sock *sk, | |
c9eaf173 | 417 | struct ccid2_seq *seqp, |
2a91aa39 AB |
418 | unsigned int *maxincr) |
419 | { | |
420 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
421 | ||
422 | /* slow start */ | |
423 | if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { | |
424 | hctx->ccid2hctx_acks = 0; | |
425 | ||
426 | /* We can increase cwnd at most maxincr [ack_ratio/2] */ | |
427 | if (*maxincr) { | |
428 | /* increase every 2 acks */ | |
429 | hctx->ccid2hctx_ssacks++; | |
430 | if (hctx->ccid2hctx_ssacks == 2) { | |
374bcf32 | 431 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd+1); |
2a91aa39 AB |
432 | hctx->ccid2hctx_ssacks = 0; |
433 | *maxincr = *maxincr - 1; | |
434 | } | |
c0c736db ACM |
435 | } else { |
436 | /* increased cwnd enough for this single ack */ | |
2a91aa39 AB |
437 | hctx->ccid2hctx_ssacks = 0; |
438 | } | |
c0c736db | 439 | } else { |
2a91aa39 AB |
440 | hctx->ccid2hctx_ssacks = 0; |
441 | hctx->ccid2hctx_acks++; | |
442 | ||
443 | if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { | |
374bcf32 | 444 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd + 1); |
2a91aa39 AB |
445 | hctx->ccid2hctx_acks = 0; |
446 | } | |
447 | } | |
448 | ||
449 | /* update RTO */ | |
450 | if (hctx->ccid2hctx_srtt == -1 || | |
29651cda AB |
451 | time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { |
452 | unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; | |
2a91aa39 AB |
453 | int s; |
454 | ||
455 | /* first measurement */ | |
456 | if (hctx->ccid2hctx_srtt == -1) { | |
457 | ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", | |
8109b02b | 458 | r, jiffies, |
234af484 | 459 | (unsigned long long)seqp->ccid2s_seq); |
593f16aa | 460 | ccid2_change_srtt(hctx, r); |
2a91aa39 | 461 | hctx->ccid2hctx_rttvar = r >> 1; |
c0c736db | 462 | } else { |
2a91aa39 AB |
463 | /* RTTVAR */ |
464 | long tmp = hctx->ccid2hctx_srtt - r; | |
593f16aa AB |
465 | long srtt; |
466 | ||
2a91aa39 AB |
467 | if (tmp < 0) |
468 | tmp *= -1; | |
469 | ||
470 | tmp >>= 2; | |
471 | hctx->ccid2hctx_rttvar *= 3; | |
472 | hctx->ccid2hctx_rttvar >>= 2; | |
473 | hctx->ccid2hctx_rttvar += tmp; | |
474 | ||
475 | /* SRTT */ | |
593f16aa AB |
476 | srtt = hctx->ccid2hctx_srtt; |
477 | srtt *= 7; | |
478 | srtt >>= 3; | |
2a91aa39 | 479 | tmp = r >> 3; |
593f16aa AB |
480 | srtt += tmp; |
481 | ccid2_change_srtt(hctx, srtt); | |
2a91aa39 AB |
482 | } |
483 | s = hctx->ccid2hctx_rttvar << 2; | |
484 | /* clock granularity is 1 when based on jiffies */ | |
485 | if (!s) | |
486 | s = 1; | |
487 | hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; | |
488 | ||
489 | /* must be at least a second */ | |
490 | s = hctx->ccid2hctx_rto / HZ; | |
491 | /* DCCP doesn't require this [but I like it cuz my code sux] */ | |
492 | #if 1 | |
493 | if (s < 1) | |
494 | hctx->ccid2hctx_rto = HZ; | |
495 | #endif | |
496 | /* max 60 seconds */ | |
497 | if (s > 60) | |
498 | hctx->ccid2hctx_rto = HZ * 60; | |
499 | ||
500 | hctx->ccid2hctx_lastrtt = jiffies; | |
501 | ||
502 | ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", | |
8109b02b ACM |
503 | hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, |
504 | hctx->ccid2hctx_rto, HZ, r); | |
2a91aa39 AB |
505 | hctx->ccid2hctx_sent = 0; |
506 | } | |
507 | ||
508 | /* we got a new ack, so re-start RTO timer */ | |
77ff72d5 | 509 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
510 | ccid2_start_rto_timer(sk); |
511 | } | |
512 | ||
77ff72d5 | 513 | static void ccid2_hc_tx_dec_pipe(struct sock *sk) |
2a91aa39 | 514 | { |
77ff72d5 AB |
515 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
516 | ||
593f16aa | 517 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1); |
2a91aa39 AB |
518 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
519 | ||
520 | if (hctx->ccid2hctx_pipe == 0) | |
77ff72d5 | 521 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
522 | } |
523 | ||
374bcf32 AB |
524 | static void ccid2_congestion_event(struct ccid2_hc_tx_sock *hctx, |
525 | struct ccid2_seq *seqp) | |
526 | { | |
527 | if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { | |
528 | ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); | |
529 | return; | |
530 | } | |
531 | ||
532 | hctx->ccid2hctx_last_cong = jiffies; | |
533 | ||
534 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1); | |
535 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; | |
536 | if (hctx->ccid2hctx_ssthresh < 2) | |
537 | hctx->ccid2hctx_ssthresh = 2; | |
538 | } | |
539 | ||
2a91aa39 AB |
540 | static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |
541 | { | |
542 | struct dccp_sock *dp = dccp_sk(sk); | |
543 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
544 | u64 ackno, seqno; | |
545 | struct ccid2_seq *seqp; | |
546 | unsigned char *vector; | |
547 | unsigned char veclen; | |
548 | int offset = 0; | |
549 | int done = 0; | |
2a91aa39 AB |
550 | unsigned int maxincr = 0; |
551 | ||
552 | ccid2_hc_tx_check_sanity(hctx); | |
553 | /* check reverse path congestion */ | |
554 | seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
555 | ||
556 | /* XXX this whole "algorithm" is broken. Need to fix it to keep track | |
557 | * of the seqnos of the dupacks so that rpseq and rpdupack are correct | |
558 | * -sorbo. | |
559 | */ | |
560 | /* need to bootstrap */ | |
561 | if (hctx->ccid2hctx_rpdupack == -1) { | |
562 | hctx->ccid2hctx_rpdupack = 0; | |
563 | hctx->ccid2hctx_rpseq = seqno; | |
c0c736db | 564 | } else { |
2a91aa39 | 565 | /* check if packet is consecutive */ |
5e28599a GR |
566 | if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1) |
567 | hctx->ccid2hctx_rpseq = seqno; | |
2a91aa39 AB |
568 | /* it's a later packet */ |
569 | else if (after48(seqno, hctx->ccid2hctx_rpseq)) { | |
570 | hctx->ccid2hctx_rpdupack++; | |
571 | ||
572 | /* check if we got enough dupacks */ | |
573 | if (hctx->ccid2hctx_rpdupack >= | |
574 | hctx->ccid2hctx_numdupack) { | |
2a91aa39 AB |
575 | hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
576 | hctx->ccid2hctx_rpseq = 0; | |
577 | ||
578 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio << 1); | |
579 | } | |
580 | } | |
581 | } | |
582 | ||
583 | /* check forward path congestion */ | |
584 | /* still didn't send out new data packets */ | |
585 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) | |
586 | return; | |
587 | ||
588 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
589 | case DCCP_PKT_ACK: | |
590 | case DCCP_PKT_DATAACK: | |
591 | break; | |
2a91aa39 AB |
592 | default: |
593 | return; | |
594 | } | |
595 | ||
596 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
32aac18d AB |
597 | if (after48(ackno, hctx->ccid2hctx_high_ack)) |
598 | hctx->ccid2hctx_high_ack = ackno; | |
599 | ||
600 | seqp = hctx->ccid2hctx_seqt; | |
601 | while (before48(seqp->ccid2s_seq, ackno)) { | |
602 | seqp = seqp->ccid2s_next; | |
603 | if (seqp == hctx->ccid2hctx_seqh) { | |
604 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
605 | break; | |
606 | } | |
607 | } | |
2a91aa39 AB |
608 | |
609 | /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for | |
610 | * this single ack. I round up. | |
611 | * -sorbo. | |
612 | */ | |
613 | maxincr = dp->dccps_l_ack_ratio >> 1; | |
614 | maxincr++; | |
615 | ||
616 | /* go through all ack vectors */ | |
617 | while ((offset = ccid2_ackvector(sk, skb, offset, | |
618 | &vector, &veclen)) != -1) { | |
619 | /* go through this ack vector */ | |
620 | while (veclen--) { | |
621 | const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; | |
622 | u64 ackno_end_rl; | |
623 | ||
624 | dccp_set_seqno(&ackno_end_rl, ackno - rl); | |
234af484 RD |
625 | ccid2_pr_debug("ackvec start:%llu end:%llu\n", |
626 | (unsigned long long)ackno, | |
627 | (unsigned long long)ackno_end_rl); | |
2a91aa39 AB |
628 | /* if the seqno we are analyzing is larger than the |
629 | * current ackno, then move towards the tail of our | |
630 | * seqnos. | |
631 | */ | |
632 | while (after48(seqp->ccid2s_seq, ackno)) { | |
633 | if (seqp == hctx->ccid2hctx_seqt) { | |
634 | done = 1; | |
635 | break; | |
636 | } | |
637 | seqp = seqp->ccid2s_prev; | |
638 | } | |
639 | if (done) | |
640 | break; | |
641 | ||
642 | /* check all seqnos in the range of the vector | |
643 | * run length | |
644 | */ | |
645 | while (between48(seqp->ccid2s_seq,ackno_end_rl,ackno)) { | |
8e27e465 AB |
646 | const u8 state = *vector & |
647 | DCCP_ACKVEC_STATE_MASK; | |
2a91aa39 AB |
648 | |
649 | /* new packet received or marked */ | |
650 | if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED && | |
651 | !seqp->ccid2s_acked) { | |
8109b02b | 652 | if (state == |
2a91aa39 | 653 | DCCP_ACKVEC_STATE_ECN_MARKED) { |
8109b02b | 654 | ccid2_congestion_event(hctx, |
374bcf32 | 655 | seqp); |
c0c736db | 656 | } else |
2a91aa39 AB |
657 | ccid2_new_ack(sk, seqp, |
658 | &maxincr); | |
2a91aa39 AB |
659 | |
660 | seqp->ccid2s_acked = 1; | |
661 | ccid2_pr_debug("Got ack for %llu\n", | |
234af484 | 662 | (unsigned long long)seqp->ccid2s_seq); |
77ff72d5 | 663 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
664 | } |
665 | if (seqp == hctx->ccid2hctx_seqt) { | |
666 | done = 1; | |
667 | break; | |
668 | } | |
3de5489f | 669 | seqp = seqp->ccid2s_prev; |
2a91aa39 AB |
670 | } |
671 | if (done) | |
672 | break; | |
673 | ||
674 | ||
675 | dccp_set_seqno(&ackno, ackno_end_rl - 1); | |
676 | vector++; | |
677 | } | |
678 | if (done) | |
679 | break; | |
680 | } | |
681 | ||
682 | /* The state about what is acked should be correct now | |
683 | * Check for NUMDUPACK | |
684 | */ | |
32aac18d AB |
685 | seqp = hctx->ccid2hctx_seqt; |
686 | while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { | |
687 | seqp = seqp->ccid2s_next; | |
688 | if (seqp == hctx->ccid2hctx_seqh) { | |
689 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
690 | break; | |
691 | } | |
692 | } | |
2a91aa39 AB |
693 | done = 0; |
694 | while (1) { | |
695 | if (seqp->ccid2s_acked) { | |
696 | done++; | |
c0c736db | 697 | if (done == hctx->ccid2hctx_numdupack) |
2a91aa39 | 698 | break; |
2a91aa39 | 699 | } |
c0c736db | 700 | if (seqp == hctx->ccid2hctx_seqt) |
2a91aa39 | 701 | break; |
2a91aa39 AB |
702 | seqp = seqp->ccid2s_prev; |
703 | } | |
704 | ||
705 | /* If there are at least 3 acknowledgements, anything unacknowledged | |
706 | * below the last sequence number is considered lost | |
707 | */ | |
708 | if (done == hctx->ccid2hctx_numdupack) { | |
709 | struct ccid2_seq *last_acked = seqp; | |
710 | ||
711 | /* check for lost packets */ | |
712 | while (1) { | |
713 | if (!seqp->ccid2s_acked) { | |
374bcf32 | 714 | ccid2_pr_debug("Packet lost: %llu\n", |
234af484 | 715 | (unsigned long long)seqp->ccid2s_seq); |
374bcf32 AB |
716 | /* XXX need to traverse from tail -> head in |
717 | * order to detect multiple congestion events in | |
718 | * one ack vector. | |
719 | */ | |
720 | ccid2_congestion_event(hctx, seqp); | |
77ff72d5 | 721 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
722 | } |
723 | if (seqp == hctx->ccid2hctx_seqt) | |
724 | break; | |
725 | seqp = seqp->ccid2s_prev; | |
726 | } | |
727 | ||
728 | hctx->ccid2hctx_seqt = last_acked; | |
729 | } | |
730 | ||
731 | /* trim acked packets in tail */ | |
732 | while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { | |
733 | if (!hctx->ccid2hctx_seqt->ccid2s_acked) | |
734 | break; | |
735 | ||
736 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; | |
737 | } | |
738 | ||
2a91aa39 AB |
739 | ccid2_hc_tx_check_sanity(hctx); |
740 | } | |
741 | ||
91f0ebf7 | 742 | static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) |
2a91aa39 | 743 | { |
c9eaf173 | 744 | struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); |
2a91aa39 | 745 | |
374bcf32 | 746 | ccid2_change_cwnd(hctx, 1); |
d458c25c AB |
747 | /* Initialize ssthresh to infinity. This means that we will exit the |
748 | * initial slow-start after the first packet loss. This is what we | |
749 | * want. | |
750 | */ | |
751 | hctx->ccid2hctx_ssthresh = ~0; | |
2a91aa39 AB |
752 | hctx->ccid2hctx_numdupack = 3; |
753 | ||
754 | /* XXX init ~ to window size... */ | |
cd1f7d34 | 755 | if (ccid2_hc_tx_alloc_seq(hctx)) |
2a91aa39 | 756 | return -ENOMEM; |
91f0ebf7 | 757 | |
2a91aa39 | 758 | hctx->ccid2hctx_rto = 3 * HZ; |
593f16aa | 759 | ccid2_change_srtt(hctx, -1); |
2a91aa39 | 760 | hctx->ccid2hctx_rttvar = -1; |
2a91aa39 | 761 | hctx->ccid2hctx_rpdupack = -1; |
374bcf32 | 762 | hctx->ccid2hctx_last_cong = jiffies; |
b24b8a24 PE |
763 | setup_timer(&hctx->ccid2hctx_rtotimer, ccid2_hc_tx_rto_expire, |
764 | (unsigned long)sk); | |
2a91aa39 AB |
765 | |
766 | ccid2_hc_tx_check_sanity(hctx); | |
767 | return 0; | |
768 | } | |
769 | ||
770 | static void ccid2_hc_tx_exit(struct sock *sk) | |
771 | { | |
c9eaf173 | 772 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
07978aab | 773 | int i; |
2a91aa39 | 774 | |
77ff72d5 | 775 | ccid2_hc_tx_kill_rto_timer(sk); |
07978aab AB |
776 | |
777 | for (i = 0; i < hctx->ccid2hctx_seqbufc; i++) | |
778 | kfree(hctx->ccid2hctx_seqbuf[i]); | |
779 | hctx->ccid2hctx_seqbufc = 0; | |
2a91aa39 AB |
780 | } |
781 | ||
782 | static void ccid2_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) | |
783 | { | |
784 | const struct dccp_sock *dp = dccp_sk(sk); | |
785 | struct ccid2_hc_rx_sock *hcrx = ccid2_hc_rx_sk(sk); | |
786 | ||
787 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
788 | case DCCP_PKT_DATA: | |
789 | case DCCP_PKT_DATAACK: | |
790 | hcrx->ccid2hcrx_data++; | |
791 | if (hcrx->ccid2hcrx_data >= dp->dccps_r_ack_ratio) { | |
792 | dccp_send_ack(sk); | |
793 | hcrx->ccid2hcrx_data = 0; | |
794 | } | |
795 | break; | |
796 | } | |
797 | } | |
798 | ||
91f0ebf7 | 799 | static struct ccid_operations ccid2 = { |
3dd9a7c3 | 800 | .ccid_id = DCCPC_CCID2, |
2a91aa39 AB |
801 | .ccid_name = "ccid2", |
802 | .ccid_owner = THIS_MODULE, | |
91f0ebf7 | 803 | .ccid_hc_tx_obj_size = sizeof(struct ccid2_hc_tx_sock), |
2a91aa39 AB |
804 | .ccid_hc_tx_init = ccid2_hc_tx_init, |
805 | .ccid_hc_tx_exit = ccid2_hc_tx_exit, | |
806 | .ccid_hc_tx_send_packet = ccid2_hc_tx_send_packet, | |
807 | .ccid_hc_tx_packet_sent = ccid2_hc_tx_packet_sent, | |
808 | .ccid_hc_tx_packet_recv = ccid2_hc_tx_packet_recv, | |
91f0ebf7 | 809 | .ccid_hc_rx_obj_size = sizeof(struct ccid2_hc_rx_sock), |
2a91aa39 AB |
810 | .ccid_hc_rx_packet_recv = ccid2_hc_rx_packet_recv, |
811 | }; | |
812 | ||
84116716 | 813 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
042d18f9 | 814 | module_param(ccid2_debug, bool, 0444); |
2a91aa39 | 815 | MODULE_PARM_DESC(ccid2_debug, "Enable debug messages"); |
84116716 | 816 | #endif |
2a91aa39 AB |
817 | |
818 | static __init int ccid2_module_init(void) | |
819 | { | |
820 | return ccid_register(&ccid2); | |
821 | } | |
822 | module_init(ccid2_module_init); | |
823 | ||
824 | static __exit void ccid2_module_exit(void) | |
825 | { | |
826 | ccid_unregister(&ccid2); | |
827 | } | |
828 | module_exit(ccid2_module_exit); | |
829 | ||
830 | MODULE_AUTHOR("Andrea Bittau <a.bittau@cs.ucl.ac.uk>"); | |
c0c736db | 831 | MODULE_DESCRIPTION("DCCP TCP-Like (CCID2) CCID"); |
2a91aa39 AB |
832 | MODULE_LICENSE("GPL"); |
833 | MODULE_ALIAS("net-dccp-ccid-2"); |