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