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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 | ||
df054e1d | 143 | static void ccid2_change_l_ack_ratio(struct sock *sk, u32 val) |
2a91aa39 AB |
144 | { |
145 | struct dccp_sock *dp = dccp_sk(sk); | |
d50ad163 GR |
146 | u32 max_ratio = DIV_ROUND_UP(ccid2_hc_tx_sk(sk)->ccid2hctx_cwnd, 2); |
147 | ||
2a91aa39 | 148 | /* |
d50ad163 GR |
149 | * Ensure that Ack Ratio does not exceed ceil(cwnd/2), which is (2) from |
150 | * RFC 4341, 6.1.2. We ignore the statement that Ack Ratio 2 is always | |
151 | * acceptable since this causes starvation/deadlock whenever cwnd < 2. | |
152 | * The same problem arises when Ack Ratio is 0 (ie. Ack Ratio disabled). | |
2a91aa39 | 153 | */ |
d50ad163 GR |
154 | if (val == 0 || val > max_ratio) { |
155 | DCCP_WARN("Limiting Ack Ratio (%u) to %u\n", val, max_ratio); | |
156 | val = max_ratio; | |
2a91aa39 | 157 | } |
df054e1d GR |
158 | if (val > 0xFFFF) /* RFC 4340, 11.3 */ |
159 | val = 0xFFFF; | |
2a91aa39 | 160 | |
d50ad163 GR |
161 | if (val == dp->dccps_l_ack_ratio) |
162 | return; | |
163 | ||
df054e1d | 164 | ccid2_pr_debug("changing local ack ratio to %u\n", val); |
2a91aa39 AB |
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 | { |
ee196c21 GR |
170 | hctx->ccid2hctx_cwnd = val? : 1; |
171 | ccid2_pr_debug("changed cwnd to %u\n", hctx->ccid2hctx_cwnd); | |
2a91aa39 AB |
172 | } |
173 | ||
593f16aa AB |
174 | static void ccid2_change_srtt(struct ccid2_hc_tx_sock *hctx, long val) |
175 | { | |
176 | ccid2_pr_debug("change SRTT to %ld\n", val); | |
177 | hctx->ccid2hctx_srtt = val; | |
178 | } | |
179 | ||
180 | static void ccid2_change_pipe(struct ccid2_hc_tx_sock *hctx, long val) | |
181 | { | |
182 | hctx->ccid2hctx_pipe = val; | |
183 | } | |
184 | ||
2a91aa39 AB |
185 | static void ccid2_start_rto_timer(struct sock *sk); |
186 | ||
187 | static void ccid2_hc_tx_rto_expire(unsigned long data) | |
188 | { | |
189 | struct sock *sk = (struct sock *)data; | |
190 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
191 | long s; | |
192 | ||
2a91aa39 AB |
193 | bh_lock_sock(sk); |
194 | if (sock_owned_by_user(sk)) { | |
195 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
196 | jiffies + HZ / 5); | |
197 | goto out; | |
198 | } | |
199 | ||
200 | ccid2_pr_debug("RTO_EXPIRE\n"); | |
201 | ||
202 | ccid2_hc_tx_check_sanity(hctx); | |
203 | ||
204 | /* back-off timer */ | |
205 | hctx->ccid2hctx_rto <<= 1; | |
206 | ||
207 | s = hctx->ccid2hctx_rto / HZ; | |
208 | if (s > 60) | |
209 | hctx->ccid2hctx_rto = 60 * HZ; | |
210 | ||
211 | ccid2_start_rto_timer(sk); | |
212 | ||
213 | /* adjust pipe, cwnd etc */ | |
593f16aa | 214 | ccid2_change_pipe(hctx, 0); |
2a91aa39 AB |
215 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd >> 1; |
216 | if (hctx->ccid2hctx_ssthresh < 2) | |
217 | hctx->ccid2hctx_ssthresh = 2; | |
374bcf32 | 218 | ccid2_change_cwnd(hctx, 1); |
2a91aa39 AB |
219 | |
220 | /* clear state about stuff we sent */ | |
221 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqh; | |
222 | hctx->ccid2hctx_ssacks = 0; | |
223 | hctx->ccid2hctx_acks = 0; | |
2a91aa39 AB |
224 | |
225 | /* clear ack ratio state. */ | |
2a91aa39 AB |
226 | hctx->ccid2hctx_rpseq = 0; |
227 | hctx->ccid2hctx_rpdupack = -1; | |
228 | ccid2_change_l_ack_ratio(sk, 1); | |
229 | ccid2_hc_tx_check_sanity(hctx); | |
230 | out: | |
231 | bh_unlock_sock(sk); | |
77ff72d5 | 232 | sock_put(sk); |
2a91aa39 AB |
233 | } |
234 | ||
235 | static void ccid2_start_rto_timer(struct sock *sk) | |
236 | { | |
237 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
238 | ||
239 | ccid2_pr_debug("setting RTO timeout=%ld\n", hctx->ccid2hctx_rto); | |
240 | ||
241 | BUG_ON(timer_pending(&hctx->ccid2hctx_rtotimer)); | |
242 | sk_reset_timer(sk, &hctx->ccid2hctx_rtotimer, | |
243 | jiffies + hctx->ccid2hctx_rto); | |
244 | } | |
245 | ||
6b57c93d | 246 | static void ccid2_hc_tx_packet_sent(struct sock *sk, int more, unsigned int len) |
2a91aa39 AB |
247 | { |
248 | struct dccp_sock *dp = dccp_sk(sk); | |
249 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
07978aab | 250 | struct ccid2_seq *next; |
2a91aa39 AB |
251 | u64 seq; |
252 | ||
253 | ccid2_hc_tx_check_sanity(hctx); | |
254 | ||
255 | BUG_ON(!hctx->ccid2hctx_sendwait); | |
256 | hctx->ccid2hctx_sendwait = 0; | |
593f16aa | 257 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe + 1); |
2a91aa39 AB |
258 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
259 | ||
260 | /* There is an issue. What if another packet is sent between | |
261 | * packet_send() and packet_sent(). Then the sequence number would be | |
262 | * wrong. | |
263 | * -sorbo. | |
264 | */ | |
265 | seq = dp->dccps_gss; | |
266 | ||
267 | hctx->ccid2hctx_seqh->ccid2s_seq = seq; | |
268 | hctx->ccid2hctx_seqh->ccid2s_acked = 0; | |
269 | hctx->ccid2hctx_seqh->ccid2s_sent = jiffies; | |
2a91aa39 | 270 | |
07978aab AB |
271 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
272 | /* check if we need to alloc more space */ | |
273 | if (next == hctx->ccid2hctx_seqt) { | |
7d9e8931 GR |
274 | if (ccid2_hc_tx_alloc_seq(hctx)) { |
275 | DCCP_CRIT("packet history - out of memory!"); | |
276 | /* FIXME: find a more graceful way to bail out */ | |
277 | return; | |
278 | } | |
07978aab AB |
279 | next = hctx->ccid2hctx_seqh->ccid2s_next; |
280 | BUG_ON(next == hctx->ccid2hctx_seqt); | |
2a91aa39 | 281 | } |
07978aab AB |
282 | hctx->ccid2hctx_seqh = next; |
283 | ||
284 | ccid2_pr_debug("cwnd=%d pipe=%d\n", hctx->ccid2hctx_cwnd, | |
285 | hctx->ccid2hctx_pipe); | |
2a91aa39 | 286 | |
900bfed4 GR |
287 | /* |
288 | * FIXME: The code below is broken and the variables have been removed | |
289 | * from the socket struct. The `ackloss' variable was always set to 0, | |
290 | * and with arsent there are several problems: | |
291 | * (i) it doesn't just count the number of Acks, but all sent packets; | |
292 | * (ii) it is expressed in # of packets, not # of windows, so the | |
293 | * comparison below uses the wrong formula: Appendix A of RFC 4341 | |
294 | * comes up with the number K = cwnd / (R^2 - R) of consecutive windows | |
295 | * of data with no lost or marked Ack packets. If arsent were the # of | |
296 | * consecutive Acks received without loss, then Ack Ratio needs to be | |
297 | * decreased by 1 when | |
298 | * arsent >= K * cwnd / R = cwnd^2 / (R^3 - R^2) | |
299 | * where cwnd / R is the number of Acks received per window of data | |
300 | * (cf. RFC 4341, App. A). The problems are that | |
301 | * - arsent counts other packets as well; | |
302 | * - the comparison uses a formula different from RFC 4341; | |
303 | * - computing a cubic/quadratic equation each time is too complicated. | |
304 | * Hence a different algorithm is needed. | |
305 | */ | |
306 | #if 0 | |
2a91aa39 AB |
307 | /* Ack Ratio. Need to maintain a concept of how many windows we sent */ |
308 | hctx->ccid2hctx_arsent++; | |
309 | /* We had an ack loss in this window... */ | |
310 | if (hctx->ccid2hctx_ackloss) { | |
311 | if (hctx->ccid2hctx_arsent >= hctx->ccid2hctx_cwnd) { | |
c0c736db ACM |
312 | hctx->ccid2hctx_arsent = 0; |
313 | hctx->ccid2hctx_ackloss = 0; | |
2a91aa39 | 314 | } |
c0c736db ACM |
315 | } else { |
316 | /* No acks lost up to now... */ | |
2a91aa39 AB |
317 | /* decrease ack ratio if enough packets were sent */ |
318 | if (dp->dccps_l_ack_ratio > 1) { | |
319 | /* XXX don't calculate denominator each time */ | |
c0c736db ACM |
320 | int denom = dp->dccps_l_ack_ratio * dp->dccps_l_ack_ratio - |
321 | dp->dccps_l_ack_ratio; | |
2a91aa39 | 322 | |
2a91aa39 AB |
323 | denom = hctx->ccid2hctx_cwnd * hctx->ccid2hctx_cwnd / denom; |
324 | ||
325 | if (hctx->ccid2hctx_arsent >= denom) { | |
326 | ccid2_change_l_ack_ratio(sk, dp->dccps_l_ack_ratio - 1); | |
327 | hctx->ccid2hctx_arsent = 0; | |
328 | } | |
c0c736db ACM |
329 | } else { |
330 | /* we can't increase ack ratio further [1] */ | |
2a91aa39 AB |
331 | hctx->ccid2hctx_arsent = 0; /* or maybe set it to cwnd*/ |
332 | } | |
333 | } | |
900bfed4 | 334 | #endif |
2a91aa39 AB |
335 | |
336 | /* setup RTO timer */ | |
c0c736db | 337 | if (!timer_pending(&hctx->ccid2hctx_rtotimer)) |
2a91aa39 | 338 | ccid2_start_rto_timer(sk); |
c0c736db | 339 | |
8d424f6c | 340 | #ifdef CONFIG_IP_DCCP_CCID2_DEBUG |
2a91aa39 | 341 | ccid2_pr_debug("pipe=%d\n", hctx->ccid2hctx_pipe); |
234af484 | 342 | ccid2_pr_debug("Sent: seq=%llu\n", (unsigned long long)seq); |
2a91aa39 AB |
343 | do { |
344 | struct ccid2_seq *seqp = hctx->ccid2hctx_seqt; | |
345 | ||
346 | while (seqp != hctx->ccid2hctx_seqh) { | |
347 | ccid2_pr_debug("out seq=%llu acked=%d time=%lu\n", | |
8109b02b | 348 | (unsigned long long)seqp->ccid2s_seq, |
234af484 | 349 | seqp->ccid2s_acked, seqp->ccid2s_sent); |
2a91aa39 AB |
350 | seqp = seqp->ccid2s_next; |
351 | } | |
c0c736db | 352 | } while (0); |
2a91aa39 AB |
353 | ccid2_pr_debug("=========\n"); |
354 | ccid2_hc_tx_check_sanity(hctx); | |
355 | #endif | |
356 | } | |
357 | ||
358 | /* XXX Lame code duplication! | |
359 | * returns -1 if none was found. | |
360 | * else returns the next offset to use in the function call. | |
361 | */ | |
362 | static int ccid2_ackvector(struct sock *sk, struct sk_buff *skb, int offset, | |
363 | unsigned char **vec, unsigned char *veclen) | |
364 | { | |
c9eaf173 YH |
365 | const struct dccp_hdr *dh = dccp_hdr(skb); |
366 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
367 | unsigned char *opt_ptr; | |
368 | const unsigned char *opt_end = (unsigned char *)dh + | |
369 | (dh->dccph_doff * 4); | |
370 | unsigned char opt, len; | |
371 | unsigned char *value; | |
2a91aa39 AB |
372 | |
373 | BUG_ON(offset < 0); | |
374 | options += offset; | |
375 | opt_ptr = options; | |
376 | if (opt_ptr >= opt_end) | |
377 | return -1; | |
378 | ||
379 | while (opt_ptr != opt_end) { | |
c9eaf173 YH |
380 | opt = *opt_ptr++; |
381 | len = 0; | |
382 | value = NULL; | |
383 | ||
384 | /* Check if this isn't a single byte option */ | |
385 | if (opt > DCCPO_MAX_RESERVED) { | |
386 | if (opt_ptr == opt_end) | |
387 | goto out_invalid_option; | |
388 | ||
389 | len = *opt_ptr++; | |
390 | if (len < 3) | |
391 | goto out_invalid_option; | |
392 | /* | |
393 | * Remove the type and len fields, leaving | |
394 | * just the value size | |
395 | */ | |
396 | len -= 2; | |
397 | value = opt_ptr; | |
398 | opt_ptr += len; | |
399 | ||
400 | if (opt_ptr > opt_end) | |
401 | goto out_invalid_option; | |
402 | } | |
2a91aa39 AB |
403 | |
404 | switch (opt) { | |
405 | case DCCPO_ACK_VECTOR_0: | |
406 | case DCCPO_ACK_VECTOR_1: | |
407 | *vec = value; | |
408 | *veclen = len; | |
409 | return offset + (opt_ptr - options); | |
2a91aa39 AB |
410 | } |
411 | } | |
412 | ||
413 | return -1; | |
414 | ||
415 | out_invalid_option: | |
59348b19 | 416 | DCCP_BUG("Invalid option - this should not happen (previous parsing)!"); |
2a91aa39 AB |
417 | return -1; |
418 | } | |
419 | ||
77ff72d5 | 420 | static void ccid2_hc_tx_kill_rto_timer(struct sock *sk) |
2a91aa39 | 421 | { |
77ff72d5 AB |
422 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
423 | ||
424 | sk_stop_timer(sk, &hctx->ccid2hctx_rtotimer); | |
425 | ccid2_pr_debug("deleted RTO timer\n"); | |
2a91aa39 AB |
426 | } |
427 | ||
428 | static inline void ccid2_new_ack(struct sock *sk, | |
c9eaf173 | 429 | struct ccid2_seq *seqp, |
2a91aa39 AB |
430 | unsigned int *maxincr) |
431 | { | |
432 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
433 | ||
434 | /* slow start */ | |
435 | if (hctx->ccid2hctx_cwnd < hctx->ccid2hctx_ssthresh) { | |
436 | hctx->ccid2hctx_acks = 0; | |
437 | ||
438 | /* We can increase cwnd at most maxincr [ack_ratio/2] */ | |
439 | if (*maxincr) { | |
440 | /* increase every 2 acks */ | |
441 | hctx->ccid2hctx_ssacks++; | |
442 | if (hctx->ccid2hctx_ssacks == 2) { | |
374bcf32 | 443 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd+1); |
2a91aa39 AB |
444 | hctx->ccid2hctx_ssacks = 0; |
445 | *maxincr = *maxincr - 1; | |
446 | } | |
c0c736db ACM |
447 | } else { |
448 | /* increased cwnd enough for this single ack */ | |
2a91aa39 AB |
449 | hctx->ccid2hctx_ssacks = 0; |
450 | } | |
c0c736db | 451 | } else { |
2a91aa39 AB |
452 | hctx->ccid2hctx_ssacks = 0; |
453 | hctx->ccid2hctx_acks++; | |
454 | ||
455 | if (hctx->ccid2hctx_acks >= hctx->ccid2hctx_cwnd) { | |
374bcf32 | 456 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd + 1); |
2a91aa39 AB |
457 | hctx->ccid2hctx_acks = 0; |
458 | } | |
459 | } | |
460 | ||
461 | /* update RTO */ | |
462 | if (hctx->ccid2hctx_srtt == -1 || | |
29651cda AB |
463 | time_after(jiffies, hctx->ccid2hctx_lastrtt + hctx->ccid2hctx_srtt)) { |
464 | unsigned long r = (long)jiffies - (long)seqp->ccid2s_sent; | |
2a91aa39 AB |
465 | int s; |
466 | ||
467 | /* first measurement */ | |
468 | if (hctx->ccid2hctx_srtt == -1) { | |
469 | ccid2_pr_debug("R: %lu Time=%lu seq=%llu\n", | |
8109b02b | 470 | r, jiffies, |
234af484 | 471 | (unsigned long long)seqp->ccid2s_seq); |
593f16aa | 472 | ccid2_change_srtt(hctx, r); |
2a91aa39 | 473 | hctx->ccid2hctx_rttvar = r >> 1; |
c0c736db | 474 | } else { |
2a91aa39 AB |
475 | /* RTTVAR */ |
476 | long tmp = hctx->ccid2hctx_srtt - r; | |
593f16aa AB |
477 | long srtt; |
478 | ||
2a91aa39 AB |
479 | if (tmp < 0) |
480 | tmp *= -1; | |
481 | ||
482 | tmp >>= 2; | |
483 | hctx->ccid2hctx_rttvar *= 3; | |
484 | hctx->ccid2hctx_rttvar >>= 2; | |
485 | hctx->ccid2hctx_rttvar += tmp; | |
486 | ||
487 | /* SRTT */ | |
593f16aa AB |
488 | srtt = hctx->ccid2hctx_srtt; |
489 | srtt *= 7; | |
490 | srtt >>= 3; | |
2a91aa39 | 491 | tmp = r >> 3; |
593f16aa AB |
492 | srtt += tmp; |
493 | ccid2_change_srtt(hctx, srtt); | |
2a91aa39 AB |
494 | } |
495 | s = hctx->ccid2hctx_rttvar << 2; | |
496 | /* clock granularity is 1 when based on jiffies */ | |
497 | if (!s) | |
498 | s = 1; | |
499 | hctx->ccid2hctx_rto = hctx->ccid2hctx_srtt + s; | |
500 | ||
501 | /* must be at least a second */ | |
502 | s = hctx->ccid2hctx_rto / HZ; | |
503 | /* DCCP doesn't require this [but I like it cuz my code sux] */ | |
504 | #if 1 | |
505 | if (s < 1) | |
506 | hctx->ccid2hctx_rto = HZ; | |
507 | #endif | |
508 | /* max 60 seconds */ | |
509 | if (s > 60) | |
510 | hctx->ccid2hctx_rto = HZ * 60; | |
511 | ||
512 | hctx->ccid2hctx_lastrtt = jiffies; | |
513 | ||
514 | ccid2_pr_debug("srtt: %ld rttvar: %ld rto: %ld (HZ=%d) R=%lu\n", | |
8109b02b ACM |
515 | hctx->ccid2hctx_srtt, hctx->ccid2hctx_rttvar, |
516 | hctx->ccid2hctx_rto, HZ, r); | |
2a91aa39 AB |
517 | } |
518 | ||
519 | /* we got a new ack, so re-start RTO timer */ | |
77ff72d5 | 520 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
521 | ccid2_start_rto_timer(sk); |
522 | } | |
523 | ||
77ff72d5 | 524 | static void ccid2_hc_tx_dec_pipe(struct sock *sk) |
2a91aa39 | 525 | { |
77ff72d5 AB |
526 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
527 | ||
593f16aa | 528 | ccid2_change_pipe(hctx, hctx->ccid2hctx_pipe-1); |
2a91aa39 AB |
529 | BUG_ON(hctx->ccid2hctx_pipe < 0); |
530 | ||
531 | if (hctx->ccid2hctx_pipe == 0) | |
77ff72d5 | 532 | ccid2_hc_tx_kill_rto_timer(sk); |
2a91aa39 AB |
533 | } |
534 | ||
d50ad163 | 535 | static void ccid2_congestion_event(struct sock *sk, struct ccid2_seq *seqp) |
374bcf32 | 536 | { |
d50ad163 GR |
537 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); |
538 | ||
374bcf32 AB |
539 | if (time_before(seqp->ccid2s_sent, hctx->ccid2hctx_last_cong)) { |
540 | ccid2_pr_debug("Multiple losses in an RTT---treating as one\n"); | |
541 | return; | |
542 | } | |
543 | ||
544 | hctx->ccid2hctx_last_cong = jiffies; | |
545 | ||
546 | ccid2_change_cwnd(hctx, hctx->ccid2hctx_cwnd >> 1); | |
547 | hctx->ccid2hctx_ssthresh = hctx->ccid2hctx_cwnd; | |
548 | if (hctx->ccid2hctx_ssthresh < 2) | |
549 | hctx->ccid2hctx_ssthresh = 2; | |
d50ad163 GR |
550 | |
551 | /* Avoid spurious timeouts resulting from Ack Ratio > cwnd */ | |
552 | if (dccp_sk(sk)->dccps_l_ack_ratio > hctx->ccid2hctx_cwnd) | |
553 | ccid2_change_l_ack_ratio(sk, hctx->ccid2hctx_cwnd); | |
374bcf32 AB |
554 | } |
555 | ||
2a91aa39 AB |
556 | static void ccid2_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) |
557 | { | |
558 | struct dccp_sock *dp = dccp_sk(sk); | |
559 | struct ccid2_hc_tx_sock *hctx = ccid2_hc_tx_sk(sk); | |
560 | u64 ackno, seqno; | |
561 | struct ccid2_seq *seqp; | |
562 | unsigned char *vector; | |
563 | unsigned char veclen; | |
564 | int offset = 0; | |
565 | int done = 0; | |
2a91aa39 AB |
566 | unsigned int maxincr = 0; |
567 | ||
568 | ccid2_hc_tx_check_sanity(hctx); | |
569 | /* check reverse path congestion */ | |
570 | seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
571 | ||
572 | /* XXX this whole "algorithm" is broken. Need to fix it to keep track | |
573 | * of the seqnos of the dupacks so that rpseq and rpdupack are correct | |
574 | * -sorbo. | |
575 | */ | |
576 | /* need to bootstrap */ | |
577 | if (hctx->ccid2hctx_rpdupack == -1) { | |
578 | hctx->ccid2hctx_rpdupack = 0; | |
579 | hctx->ccid2hctx_rpseq = seqno; | |
c0c736db | 580 | } else { |
2a91aa39 | 581 | /* check if packet is consecutive */ |
5e28599a GR |
582 | if (dccp_delta_seqno(hctx->ccid2hctx_rpseq, seqno) == 1) |
583 | hctx->ccid2hctx_rpseq = seqno; | |
2a91aa39 AB |
584 | /* it's a later packet */ |
585 | else if (after48(seqno, hctx->ccid2hctx_rpseq)) { | |
586 | hctx->ccid2hctx_rpdupack++; | |
587 | ||
588 | /* check if we got enough dupacks */ | |
589 | if (hctx->ccid2hctx_rpdupack >= | |
590 | hctx->ccid2hctx_numdupack) { | |
2a91aa39 AB |
591 | hctx->ccid2hctx_rpdupack = -1; /* XXX lame */ |
592 | hctx->ccid2hctx_rpseq = 0; | |
593 | ||
df054e1d | 594 | ccid2_change_l_ack_ratio(sk, 2 * dp->dccps_l_ack_ratio); |
2a91aa39 AB |
595 | } |
596 | } | |
597 | } | |
598 | ||
599 | /* check forward path congestion */ | |
600 | /* still didn't send out new data packets */ | |
601 | if (hctx->ccid2hctx_seqh == hctx->ccid2hctx_seqt) | |
602 | return; | |
603 | ||
604 | switch (DCCP_SKB_CB(skb)->dccpd_type) { | |
605 | case DCCP_PKT_ACK: | |
606 | case DCCP_PKT_DATAACK: | |
607 | break; | |
2a91aa39 AB |
608 | default: |
609 | return; | |
610 | } | |
611 | ||
612 | ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; | |
32aac18d AB |
613 | if (after48(ackno, hctx->ccid2hctx_high_ack)) |
614 | hctx->ccid2hctx_high_ack = ackno; | |
615 | ||
616 | seqp = hctx->ccid2hctx_seqt; | |
617 | while (before48(seqp->ccid2s_seq, ackno)) { | |
618 | seqp = seqp->ccid2s_next; | |
619 | if (seqp == hctx->ccid2hctx_seqh) { | |
620 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
621 | break; | |
622 | } | |
623 | } | |
2a91aa39 AB |
624 | |
625 | /* If in slow-start, cwnd can increase at most Ack Ratio / 2 packets for | |
626 | * this single ack. I round up. | |
627 | * -sorbo. | |
628 | */ | |
629 | maxincr = dp->dccps_l_ack_ratio >> 1; | |
630 | maxincr++; | |
631 | ||
632 | /* go through all ack vectors */ | |
633 | while ((offset = ccid2_ackvector(sk, skb, offset, | |
634 | &vector, &veclen)) != -1) { | |
635 | /* go through this ack vector */ | |
636 | while (veclen--) { | |
637 | const u8 rl = *vector & DCCP_ACKVEC_LEN_MASK; | |
cfbbeabc | 638 | u64 ackno_end_rl = SUB48(ackno, rl); |
2a91aa39 | 639 | |
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) { | |
8109b02b | 667 | if (state == |
2a91aa39 | 668 | DCCP_ACKVEC_STATE_ECN_MARKED) { |
d50ad163 | 669 | ccid2_congestion_event(sk, |
374bcf32 | 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 | } | |
3de5489f | 684 | seqp = seqp->ccid2s_prev; |
2a91aa39 AB |
685 | } |
686 | if (done) | |
687 | break; | |
688 | ||
cfbbeabc | 689 | ackno = SUB48(ackno_end_rl, 1); |
2a91aa39 AB |
690 | vector++; |
691 | } | |
692 | if (done) | |
693 | break; | |
694 | } | |
695 | ||
696 | /* The state about what is acked should be correct now | |
697 | * Check for NUMDUPACK | |
698 | */ | |
32aac18d AB |
699 | seqp = hctx->ccid2hctx_seqt; |
700 | while (before48(seqp->ccid2s_seq, hctx->ccid2hctx_high_ack)) { | |
701 | seqp = seqp->ccid2s_next; | |
702 | if (seqp == hctx->ccid2hctx_seqh) { | |
703 | seqp = hctx->ccid2hctx_seqh->ccid2s_prev; | |
704 | break; | |
705 | } | |
706 | } | |
2a91aa39 AB |
707 | done = 0; |
708 | while (1) { | |
709 | if (seqp->ccid2s_acked) { | |
710 | done++; | |
c0c736db | 711 | if (done == hctx->ccid2hctx_numdupack) |
2a91aa39 | 712 | break; |
2a91aa39 | 713 | } |
c0c736db | 714 | if (seqp == hctx->ccid2hctx_seqt) |
2a91aa39 | 715 | break; |
2a91aa39 AB |
716 | seqp = seqp->ccid2s_prev; |
717 | } | |
718 | ||
719 | /* If there are at least 3 acknowledgements, anything unacknowledged | |
720 | * below the last sequence number is considered lost | |
721 | */ | |
722 | if (done == hctx->ccid2hctx_numdupack) { | |
723 | struct ccid2_seq *last_acked = seqp; | |
724 | ||
725 | /* check for lost packets */ | |
726 | while (1) { | |
727 | if (!seqp->ccid2s_acked) { | |
374bcf32 | 728 | ccid2_pr_debug("Packet lost: %llu\n", |
234af484 | 729 | (unsigned long long)seqp->ccid2s_seq); |
374bcf32 AB |
730 | /* XXX need to traverse from tail -> head in |
731 | * order to detect multiple congestion events in | |
732 | * one ack vector. | |
733 | */ | |
d50ad163 | 734 | ccid2_congestion_event(sk, seqp); |
77ff72d5 | 735 | ccid2_hc_tx_dec_pipe(sk); |
2a91aa39 AB |
736 | } |
737 | if (seqp == hctx->ccid2hctx_seqt) | |
738 | break; | |
739 | seqp = seqp->ccid2s_prev; | |
740 | } | |
741 | ||
742 | hctx->ccid2hctx_seqt = last_acked; | |
743 | } | |
744 | ||
745 | /* trim acked packets in tail */ | |
746 | while (hctx->ccid2hctx_seqt != hctx->ccid2hctx_seqh) { | |
747 | if (!hctx->ccid2hctx_seqt->ccid2s_acked) | |
748 | break; | |
749 | ||
750 | hctx->ccid2hctx_seqt = hctx->ccid2hctx_seqt->ccid2s_next; | |
751 | } | |
752 | ||
2a91aa39 AB |
753 | ccid2_hc_tx_check_sanity(hctx); |
754 | } | |
755 | ||
91f0ebf7 | 756 | static int ccid2_hc_tx_init(struct ccid *ccid, struct sock *sk) |
2a91aa39 | 757 | { |
c9eaf173 | 758 | struct ccid2_hc_tx_sock *hctx = ccid_priv(ccid); |
b00d2bbc GR |
759 | struct dccp_sock *dp = dccp_sk(sk); |
760 | u32 max_ratio; | |
2a91aa39 | 761 | |
b00d2bbc | 762 | /* RFC 4341, 5: initialise ssthresh to arbitrarily high (max) value */ |
d458c25c | 763 | hctx->ccid2hctx_ssthresh = ~0; |
2a91aa39 AB |
764 | hctx->ccid2hctx_numdupack = 3; |
765 | ||
b00d2bbc GR |
766 | /* |
767 | * RFC 4341, 5: "The cwnd parameter is initialized to at most four | |
768 | * packets for new connections, following the rules from [RFC3390]". | |
769 | * We need to convert the bytes of RFC3390 into the packets of RFC 4341. | |
770 | */ | |
771 | hctx->ccid2hctx_cwnd = min(4U, max(2U, 4380U / dp->dccps_mss_cache)); | |
772 | ||
773 | /* Make sure that Ack Ratio is enabled and within bounds. */ | |
774 | max_ratio = DIV_ROUND_UP(hctx->ccid2hctx_cwnd, 2); | |
775 | if (dp->dccps_l_ack_ratio == 0 || dp->dccps_l_ack_ratio > max_ratio) | |
776 | dp->dccps_l_ack_ratio = max_ratio; | |
777 | ||
2a91aa39 | 778 | /* XXX init ~ to window size... */ |
cd1f7d34 | 779 | if (ccid2_hc_tx_alloc_seq(hctx)) |
2a91aa39 | 780 | return -ENOMEM; |
91f0ebf7 | 781 | |
2a91aa39 | 782 | hctx->ccid2hctx_rto = 3 * HZ; |
593f16aa | 783 | ccid2_change_srtt(hctx, -1); |
2a91aa39 | 784 | hctx->ccid2hctx_rttvar = -1; |
2a91aa39 | 785 | hctx->ccid2hctx_rpdupack = -1; |
374bcf32 | 786 | hctx->ccid2hctx_last_cong = jiffies; |
b24b8a24 PE |
787 | setup_timer(&hctx->ccid2hctx_rtotimer, ccid2_hc_tx_rto_expire, |
788 | (unsigned long)sk); | |
2a91aa39 AB |
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"); |