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Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/options.c | |
3 | * | |
4 | * An implementation of the DCCP protocol | |
1bc09869 IM |
5 | * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> |
6 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> | |
7 | * Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz> | |
7c657876 ACM |
8 | * |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License | |
11 | * as published by the Free Software Foundation; either version | |
12 | * 2 of the License, or (at your option) any later version. | |
13 | */ | |
14 | #include <linux/config.h> | |
15 | #include <linux/dccp.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/skbuff.h> | |
20 | ||
21 | #include "ccid.h" | |
22 | #include "dccp.h" | |
23 | ||
24 | static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap, | |
25 | struct sock *sk, | |
26 | const u64 ackno, | |
27 | const unsigned char len, | |
28 | const unsigned char *vector); | |
29 | ||
30 | /* stores the default values for new connection. may be changed with sysctl */ | |
31 | static const struct dccp_options dccpo_default_values = { | |
32 | .dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW, | |
33 | .dccpo_ccid = DCCPF_INITIAL_CCID, | |
34 | .dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR, | |
35 | .dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT, | |
36 | }; | |
37 | ||
38 | void dccp_options_init(struct dccp_options *dccpo) | |
39 | { | |
40 | memcpy(dccpo, &dccpo_default_values, sizeof(*dccpo)); | |
41 | } | |
42 | ||
43 | static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) | |
44 | { | |
45 | u32 value = 0; | |
46 | ||
47 | if (len > 3) | |
48 | value += *bf++ << 24; | |
49 | if (len > 2) | |
50 | value += *bf++ << 16; | |
51 | if (len > 1) | |
52 | value += *bf++ << 8; | |
53 | if (len > 0) | |
54 | value += *bf; | |
55 | ||
56 | return value; | |
57 | } | |
58 | ||
59 | int dccp_parse_options(struct sock *sk, struct sk_buff *skb) | |
60 | { | |
61 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 62 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
63 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
64 | "CLIENT rx opt: " : "server rx opt: "; | |
7c657876 ACM |
65 | #endif |
66 | const struct dccp_hdr *dh = dccp_hdr(skb); | |
67 | const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; | |
68 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
69 | unsigned char *opt_ptr = options; | |
7690af3f ACM |
70 | const unsigned char *opt_end = (unsigned char *)dh + |
71 | (dh->dccph_doff * 4); | |
7c657876 ACM |
72 | struct dccp_options_received *opt_recv = &dp->dccps_options_received; |
73 | unsigned char opt, len; | |
74 | unsigned char *value; | |
1c14ac0a | 75 | u32 elapsed_time; |
7c657876 ACM |
76 | |
77 | memset(opt_recv, 0, sizeof(*opt_recv)); | |
78 | ||
79 | while (opt_ptr != opt_end) { | |
80 | opt = *opt_ptr++; | |
81 | len = 0; | |
82 | value = NULL; | |
83 | ||
84 | /* Check if this isn't a single byte option */ | |
85 | if (opt > DCCPO_MAX_RESERVED) { | |
86 | if (opt_ptr == opt_end) | |
87 | goto out_invalid_option; | |
88 | ||
89 | len = *opt_ptr++; | |
90 | if (len < 3) | |
91 | goto out_invalid_option; | |
92 | /* | |
93 | * Remove the type and len fields, leaving | |
94 | * just the value size | |
95 | */ | |
96 | len -= 2; | |
97 | value = opt_ptr; | |
98 | opt_ptr += len; | |
99 | ||
100 | if (opt_ptr > opt_end) | |
101 | goto out_invalid_option; | |
102 | } | |
103 | ||
104 | switch (opt) { | |
105 | case DCCPO_PADDING: | |
106 | break; | |
107 | case DCCPO_NDP_COUNT: | |
108 | if (len > 3) | |
109 | goto out_invalid_option; | |
110 | ||
111 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
7690af3f ACM |
112 | dccp_pr_debug("%sNDP count=%d\n", debug_prefix, |
113 | opt_recv->dccpor_ndp); | |
7c657876 ACM |
114 | break; |
115 | case DCCPO_ACK_VECTOR_0: | |
116 | if (len > DCCP_MAX_ACK_VECTOR_LEN) | |
117 | goto out_invalid_option; | |
118 | ||
119 | if (pkt_type == DCCP_PKT_DATA) | |
120 | continue; | |
121 | ||
122 | opt_recv->dccpor_ack_vector_len = len; | |
123 | opt_recv->dccpor_ack_vector_idx = value - options; | |
124 | ||
125 | dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n", | |
f6ccf554 DM |
126 | debug_prefix, len, |
127 | (unsigned long long) | |
128 | DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
129 | dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
130 | value, len); | |
7690af3f ACM |
131 | dccp_ackpkts_check_rcv_ackvector(dp->dccps_hc_rx_ackpkts, |
132 | sk, | |
133 | DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
7c657876 ACM |
134 | len, value); |
135 | break; | |
136 | case DCCPO_TIMESTAMP: | |
137 | if (len != 4) | |
138 | goto out_invalid_option; | |
139 | ||
140 | opt_recv->dccpor_timestamp = ntohl(*(u32 *)value); | |
141 | ||
142 | dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp; | |
b0e56780 | 143 | dccp_timestamp(sk, &dp->dccps_timestamp_time); |
7c657876 ACM |
144 | |
145 | dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n", | |
146 | debug_prefix, opt_recv->dccpor_timestamp, | |
f6ccf554 | 147 | (unsigned long long) |
7c657876 ACM |
148 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
149 | break; | |
150 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 151 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
152 | goto out_invalid_option; |
153 | ||
154 | opt_recv->dccpor_timestamp_echo = ntohl(*(u32 *)value); | |
155 | ||
1bc09869 | 156 | dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ", |
7690af3f ACM |
157 | debug_prefix, |
158 | opt_recv->dccpor_timestamp_echo, | |
f6ccf554 DM |
159 | len + 2, |
160 | (unsigned long long) | |
1bc09869 IM |
161 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
162 | ||
1bc09869 | 163 | |
1c14ac0a ACM |
164 | if (len == 4) |
165 | break; | |
166 | ||
167 | if (len == 6) | |
168 | elapsed_time = ntohs(*(u16 *)(value + 4)); | |
169 | else | |
170 | elapsed_time = ntohl(*(u32 *)(value + 4)); | |
171 | ||
172 | /* Give precedence to the biggest ELAPSED_TIME */ | |
173 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
174 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
175 | break; |
176 | case DCCPO_ELAPSED_TIME: | |
1bc09869 | 177 | if (len != 2 && len != 4) |
7c657876 ACM |
178 | goto out_invalid_option; |
179 | ||
180 | if (pkt_type == DCCP_PKT_DATA) | |
181 | continue; | |
1bc09869 IM |
182 | |
183 | if (len == 2) | |
1c14ac0a | 184 | elapsed_time = ntohs(*(u16 *)value); |
1bc09869 | 185 | else |
1c14ac0a ACM |
186 | elapsed_time = ntohl(*(u32 *)value); |
187 | ||
188 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
189 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 190 | |
7c657876 | 191 | dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix, |
1c14ac0a | 192 | elapsed_time); |
7c657876 ACM |
193 | break; |
194 | /* | |
195 | * From draft-ietf-dccp-spec-11.txt: | |
196 | * | |
7690af3f ACM |
197 | * Option numbers 128 through 191 are for |
198 | * options sent from the HC-Sender to the | |
199 | * HC-Receiver; option numbers 192 through 255 | |
200 | * are for options sent from the HC-Receiver to | |
201 | * the HC-Sender. | |
7c657876 ACM |
202 | */ |
203 | case 128 ... 191: { | |
204 | const u16 idx = value - options; | |
205 | ||
7690af3f ACM |
206 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
207 | opt, len, idx, | |
208 | value) != 0) | |
7c657876 ACM |
209 | goto out_invalid_option; |
210 | } | |
211 | break; | |
212 | case 192 ... 255: { | |
213 | const u16 idx = value - options; | |
214 | ||
7690af3f ACM |
215 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
216 | opt, len, idx, | |
217 | value) != 0) | |
7c657876 ACM |
218 | goto out_invalid_option; |
219 | } | |
220 | break; | |
221 | default: | |
7690af3f ACM |
222 | pr_info("DCCP(%p): option %d(len=%d) not " |
223 | "implemented, ignoring\n", | |
7c657876 ACM |
224 | sk, opt, len); |
225 | break; | |
226 | } | |
227 | } | |
228 | ||
229 | return 0; | |
230 | ||
231 | out_invalid_option: | |
232 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
233 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR; | |
234 | pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len); | |
235 | return -1; | |
236 | } | |
237 | ||
238 | static void dccp_encode_value_var(const u32 value, unsigned char *to, | |
239 | const unsigned int len) | |
240 | { | |
241 | if (len > 3) | |
242 | *to++ = (value & 0xFF000000) >> 24; | |
243 | if (len > 2) | |
244 | *to++ = (value & 0xFF0000) >> 16; | |
245 | if (len > 1) | |
246 | *to++ = (value & 0xFF00) >> 8; | |
247 | if (len > 0) | |
248 | *to++ = (value & 0xFF); | |
249 | } | |
250 | ||
251 | static inline int dccp_ndp_len(const int ndp) | |
252 | { | |
253 | return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3; | |
254 | } | |
255 | ||
256 | void dccp_insert_option(struct sock *sk, struct sk_buff *skb, | |
257 | const unsigned char option, | |
258 | const void *value, const unsigned char len) | |
259 | { | |
260 | unsigned char *to; | |
261 | ||
262 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
263 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert " |
264 | "%d option!\n", option); | |
7c657876 ACM |
265 | return; |
266 | } | |
267 | ||
268 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
269 | ||
270 | to = skb_push(skb, len + 2); | |
271 | *to++ = option; | |
272 | *to++ = len + 2; | |
273 | ||
274 | memcpy(to, value, len); | |
275 | } | |
276 | ||
277 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
278 | ||
279 | static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) | |
280 | { | |
281 | struct dccp_sock *dp = dccp_sk(sk); | |
282 | int ndp = dp->dccps_ndp_count; | |
283 | ||
284 | if (dccp_non_data_packet(skb)) | |
285 | ++dp->dccps_ndp_count; | |
286 | else | |
287 | dp->dccps_ndp_count = 0; | |
288 | ||
289 | if (ndp > 0) { | |
290 | unsigned char *ptr; | |
291 | const int ndp_len = dccp_ndp_len(ndp); | |
292 | const int len = ndp_len + 2; | |
293 | ||
294 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
295 | return; | |
296 | ||
297 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
298 | ||
299 | ptr = skb_push(skb, len); | |
300 | *ptr++ = DCCPO_NDP_COUNT; | |
301 | *ptr++ = len; | |
302 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
303 | } | |
304 | } | |
305 | ||
306 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
307 | { | |
b1c9fe7b | 308 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
309 | } |
310 | ||
311 | void dccp_insert_option_elapsed_time(struct sock *sk, | |
312 | struct sk_buff *skb, | |
313 | u32 elapsed_time) | |
314 | { | |
725ba8ee | 315 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 316 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
317 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
318 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
319 | #endif |
320 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); | |
321 | const int len = 2 + elapsed_time_len; | |
322 | unsigned char *to; | |
323 | ||
1bc09869 | 324 | if (elapsed_time_len == 0) |
7c657876 ACM |
325 | return; |
326 | ||
327 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
328 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to " |
329 | "insert elapsed time!\n"); | |
7c657876 ACM |
330 | return; |
331 | } | |
332 | ||
333 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
334 | ||
335 | to = skb_push(skb, len); | |
336 | *to++ = DCCPO_ELAPSED_TIME; | |
337 | *to++ = len; | |
338 | ||
1bc09869 IM |
339 | if (elapsed_time_len == 2) { |
340 | const u16 var16 = htons((u16)elapsed_time); | |
341 | memcpy(to, &var16, 2); | |
342 | } else { | |
343 | const u32 var32 = htonl(elapsed_time); | |
344 | memcpy(to, &var32, 4); | |
345 | } | |
7c657876 ACM |
346 | |
347 | dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n", | |
348 | debug_prefix, elapsed_time, | |
f6ccf554 DM |
349 | len, |
350 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); | |
7c657876 ACM |
351 | } |
352 | ||
d4b81ff7 | 353 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 ACM |
354 | |
355 | static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb) | |
356 | { | |
357 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 358 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
359 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
360 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
361 | #endif |
362 | struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts; | |
363 | int len = ap->dccpap_buf_vector_len + 2; | |
b0e56780 ACM |
364 | struct timeval now; |
365 | u32 elapsed_time; | |
7c657876 ACM |
366 | unsigned char *to, *from; |
367 | ||
b0e56780 ACM |
368 | dccp_timestamp(sk, &now); |
369 | elapsed_time = timeval_delta(&now, &ap->dccpap_time) / 10; | |
370 | ||
7c657876 ACM |
371 | if (elapsed_time != 0) |
372 | dccp_insert_option_elapsed_time(sk, skb, elapsed_time); | |
373 | ||
374 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
375 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to " |
376 | "insert ACK Vector!\n"); | |
7c657876 ACM |
377 | return; |
378 | } | |
379 | ||
380 | /* | |
381 | * XXX: now we have just one ack vector sent record, so | |
382 | * we have to wait for it to be cleared. | |
383 | * | |
384 | * Of course this is not acceptable, but this is just for | |
385 | * basic testing now. | |
386 | */ | |
387 | if (ap->dccpap_ack_seqno != DCCP_MAX_SEQNO + 1) | |
388 | return; | |
389 | ||
390 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
391 | ||
392 | to = skb_push(skb, len); | |
393 | *to++ = DCCPO_ACK_VECTOR_0; | |
394 | *to++ = len; | |
395 | ||
396 | len = ap->dccpap_buf_vector_len; | |
397 | from = ap->dccpap_buf + ap->dccpap_buf_head; | |
398 | ||
399 | /* Check if buf_head wraps */ | |
400 | if (ap->dccpap_buf_head + len > ap->dccpap_buf_len) { | |
7690af3f ACM |
401 | const unsigned int tailsize = (ap->dccpap_buf_len - |
402 | ap->dccpap_buf_head); | |
7c657876 ACM |
403 | |
404 | memcpy(to, from, tailsize); | |
405 | to += tailsize; | |
406 | len -= tailsize; | |
407 | from = ap->dccpap_buf; | |
408 | } | |
409 | ||
410 | memcpy(to, from, len); | |
411 | /* | |
412 | * From draft-ietf-dccp-spec-11.txt: | |
413 | * | |
414 | * For each acknowledgement it sends, the HC-Receiver will add an | |
415 | * acknowledgement record. ack_seqno will equal the HC-Receiver | |
416 | * sequence number it used for the ack packet; ack_ptr will equal | |
7690af3f ACM |
417 | * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will |
418 | * equal buf_nonce. | |
7c657876 ACM |
419 | * |
420 | * This implemention uses just one ack record for now. | |
421 | */ | |
422 | ap->dccpap_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
423 | ap->dccpap_ack_ptr = ap->dccpap_buf_head; | |
424 | ap->dccpap_ack_ackno = ap->dccpap_buf_ackno; | |
425 | ap->dccpap_ack_nonce = ap->dccpap_buf_nonce; | |
426 | ap->dccpap_ack_vector_len = ap->dccpap_buf_vector_len; | |
427 | ||
7690af3f ACM |
428 | dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, " |
429 | "ack_ackno=%llu\n", | |
7c657876 | 430 | debug_prefix, ap->dccpap_ack_vector_len, |
f6ccf554 DM |
431 | (unsigned long long) ap->dccpap_ack_seqno, |
432 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
433 | } |
434 | ||
b0e56780 ACM |
435 | void dccp_timestamp(const struct sock *sk, struct timeval *tv) |
436 | { | |
437 | const struct dccp_sock *dp = dccp_sk(sk); | |
438 | ||
439 | do_gettimeofday(tv); | |
440 | tv->tv_sec -= dp->dccps_epoch.tv_sec; | |
441 | tv->tv_usec -= dp->dccps_epoch.tv_usec; | |
442 | ||
443 | while (tv->tv_usec < 0) { | |
444 | tv->tv_sec--; | |
445 | tv->tv_usec += USEC_PER_SEC; | |
446 | } | |
447 | } | |
448 | ||
449 | EXPORT_SYMBOL_GPL(dccp_timestamp); | |
450 | ||
d4b81ff7 | 451 | void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 452 | { |
1bc09869 IM |
453 | struct timeval tv; |
454 | u32 now; | |
455 | ||
b0e56780 ACM |
456 | dccp_timestamp(sk, &tv); |
457 | now = timeval_usecs(&tv) / 10; | |
1bc09869 IM |
458 | /* yes this will overflow but that is the point as we want a |
459 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
460 | ||
461 | now = htonl(now); | |
7c657876 ACM |
462 | dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
463 | } | |
464 | ||
d4b81ff7 ACM |
465 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
466 | ||
7690af3f ACM |
467 | static void dccp_insert_option_timestamp_echo(struct sock *sk, |
468 | struct sk_buff *skb) | |
7c657876 ACM |
469 | { |
470 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 471 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
472 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
473 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 | 474 | #endif |
b0e56780 | 475 | struct timeval now; |
7c657876 | 476 | u32 tstamp_echo; |
b0e56780 ACM |
477 | u32 elapsed_time; |
478 | int len, elapsed_time_len; | |
7c657876 ACM |
479 | unsigned char *to; |
480 | ||
b0e56780 ACM |
481 | dccp_timestamp(sk, &now); |
482 | elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10; | |
483 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); | |
484 | len = 6 + elapsed_time_len; | |
485 | ||
7c657876 | 486 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { |
7690af3f ACM |
487 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert " |
488 | "timestamp echo!\n"); | |
7c657876 ACM |
489 | return; |
490 | } | |
491 | ||
492 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
493 | ||
494 | to = skb_push(skb, len); | |
495 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
496 | *to++ = len; | |
497 | ||
498 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
499 | memcpy(to, &tstamp_echo, 4); | |
500 | to += 4; | |
1bc09869 IM |
501 | |
502 | if (elapsed_time_len == 2) { | |
503 | const u16 var16 = htons((u16)elapsed_time); | |
504 | memcpy(to, &var16, 2); | |
505 | } else if (elapsed_time_len == 4) { | |
506 | const u32 var32 = htonl(elapsed_time); | |
507 | memcpy(to, &var32, 4); | |
508 | } | |
7c657876 ACM |
509 | |
510 | dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n", | |
511 | debug_prefix, dp->dccps_timestamp_echo, | |
f6ccf554 DM |
512 | len, |
513 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); | |
7c657876 ACM |
514 | |
515 | dp->dccps_timestamp_echo = 0; | |
1bc09869 IM |
516 | dp->dccps_timestamp_time.tv_sec = 0; |
517 | dp->dccps_timestamp_time.tv_usec = 0; | |
7c657876 ACM |
518 | } |
519 | ||
520 | void dccp_insert_options(struct sock *sk, struct sk_buff *skb) | |
521 | { | |
522 | struct dccp_sock *dp = dccp_sk(sk); | |
523 | ||
524 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
525 | ||
526 | if (dp->dccps_options.dccpo_send_ndp_count) | |
527 | dccp_insert_option_ndp(sk, skb); | |
528 | ||
529 | if (!dccp_packet_without_ack(skb)) { | |
530 | if (dp->dccps_options.dccpo_send_ack_vector && | |
7690af3f ACM |
531 | (dp->dccps_hc_rx_ackpkts->dccpap_buf_ackno != |
532 | DCCP_MAX_SEQNO + 1)) | |
7c657876 | 533 | dccp_insert_option_ack_vector(sk, skb); |
7c657876 ACM |
534 | if (dp->dccps_timestamp_echo != 0) |
535 | dccp_insert_option_timestamp_echo(sk, skb); | |
536 | } | |
537 | ||
507d37cf ACM |
538 | if (dp->dccps_hc_rx_insert_options) { |
539 | ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb); | |
540 | dp->dccps_hc_rx_insert_options = 0; | |
541 | } | |
542 | if (dp->dccps_hc_tx_insert_options) { | |
543 | ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb); | |
544 | dp->dccps_hc_tx_insert_options = 0; | |
545 | } | |
7c657876 ACM |
546 | |
547 | /* XXX: insert other options when appropriate */ | |
548 | ||
549 | if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { | |
550 | /* The length of all options has to be a multiple of 4 */ | |
551 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
552 | ||
553 | if (padding != 0) { | |
554 | padding = 4 - padding; | |
555 | memset(skb_push(skb, padding), 0, padding); | |
556 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
557 | } | |
558 | } | |
559 | } | |
560 | ||
a1d3a355 ACM |
561 | struct dccp_ackpkts *dccp_ackpkts_alloc(const unsigned int len, |
562 | const unsigned int __nocast priority) | |
7c657876 ACM |
563 | { |
564 | struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority); | |
565 | ||
566 | if (ap != NULL) { | |
725ba8ee | 567 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
568 | memset(ap->dccpap_buf, 0xFF, len); |
569 | #endif | |
7690af3f ACM |
570 | ap->dccpap_buf_len = len; |
571 | ap->dccpap_buf_head = | |
572 | ap->dccpap_buf_tail = | |
573 | ap->dccpap_buf_len - 1; | |
574 | ap->dccpap_buf_ackno = | |
575 | ap->dccpap_ack_ackno = | |
576 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
577 | ap->dccpap_buf_nonce = ap->dccpap_buf_nonce = 0; | |
578 | ap->dccpap_ack_ptr = 0; | |
1bc09869 IM |
579 | ap->dccpap_time.tv_sec = 0; |
580 | ap->dccpap_time.tv_usec = 0; | |
7c657876 ACM |
581 | ap->dccpap_buf_vector_len = ap->dccpap_ack_vector_len = 0; |
582 | } | |
583 | ||
584 | return ap; | |
585 | } | |
586 | ||
587 | void dccp_ackpkts_free(struct dccp_ackpkts *ap) | |
588 | { | |
589 | if (ap != NULL) { | |
725ba8ee | 590 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
591 | memset(ap, 0xFF, sizeof(*ap) + ap->dccpap_buf_len); |
592 | #endif | |
593 | kfree(ap); | |
594 | } | |
595 | } | |
596 | ||
597 | static inline u8 dccp_ackpkts_state(const struct dccp_ackpkts *ap, | |
598 | const unsigned int index) | |
599 | { | |
600 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_STATE_MASK; | |
601 | } | |
602 | ||
603 | static inline u8 dccp_ackpkts_len(const struct dccp_ackpkts *ap, | |
604 | const unsigned int index) | |
605 | { | |
606 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_LEN_MASK; | |
607 | } | |
608 | ||
609 | /* | |
610 | * If several packets are missing, the HC-Receiver may prefer to enter multiple | |
611 | * bytes with run length 0, rather than a single byte with a larger run length; | |
612 | * this simplifies table updates if one of the missing packets arrives. | |
613 | */ | |
614 | static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap, | |
615 | const unsigned int packets, | |
616 | const unsigned char state) | |
617 | { | |
618 | unsigned int gap; | |
619 | signed long new_head; | |
620 | ||
621 | if (ap->dccpap_buf_vector_len + packets > ap->dccpap_buf_len) | |
622 | return -ENOBUFS; | |
623 | ||
624 | gap = packets - 1; | |
625 | new_head = ap->dccpap_buf_head - packets; | |
626 | ||
627 | if (new_head < 0) { | |
628 | if (gap > 0) { | |
629 | memset(ap->dccpap_buf, DCCP_ACKPKTS_STATE_NOT_RECEIVED, | |
630 | gap + new_head + 1); | |
631 | gap = -new_head; | |
632 | } | |
633 | new_head += ap->dccpap_buf_len; | |
634 | } | |
635 | ||
636 | ap->dccpap_buf_head = new_head; | |
637 | ||
638 | if (gap > 0) | |
639 | memset(ap->dccpap_buf + ap->dccpap_buf_head + 1, | |
640 | DCCP_ACKPKTS_STATE_NOT_RECEIVED, gap); | |
641 | ||
642 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
643 | ap->dccpap_buf_vector_len += packets; | |
644 | return 0; | |
645 | } | |
646 | ||
647 | /* | |
648 | * Implements the draft-ietf-dccp-spec-11.txt Appendix A | |
649 | */ | |
b0e56780 ACM |
650 | int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk, |
651 | u64 ackno, u8 state) | |
7c657876 ACM |
652 | { |
653 | /* | |
654 | * Check at the right places if the buffer is full, if it is, tell the | |
655 | * caller to start dropping packets till the HC-Sender acks our ACK | |
656 | * vectors, when we will free up space in dccpap_buf. | |
657 | * | |
658 | * We may well decide to do buffer compression, etc, but for now lets | |
659 | * just drop. | |
660 | * | |
661 | * From Appendix A: | |
662 | * | |
7690af3f ACM |
663 | * Of course, the circular buffer may overflow, either when the |
664 | * HC-Sender is sending data at a very high rate, when the | |
665 | * HC-Receiver's acknowledgements are not reaching the HC-Sender, | |
666 | * or when the HC-Sender is forgetting to acknowledge those acks | |
667 | * (so the HC-Receiver is unable to clean up old state). In this | |
668 | * case, the HC-Receiver should either compress the buffer (by | |
669 | * increasing run lengths when possible), transfer its state to | |
670 | * a larger buffer, or, as a last resort, drop all received | |
671 | * packets, without processing them whatsoever, until its buffer | |
672 | * shrinks again. | |
7c657876 ACM |
673 | */ |
674 | ||
675 | /* See if this is the first ackno being inserted */ | |
676 | if (ap->dccpap_buf_vector_len == 0) { | |
677 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
678 | ap->dccpap_buf_vector_len = 1; | |
679 | } else if (after48(ackno, ap->dccpap_buf_ackno)) { | |
7690af3f ACM |
680 | const u64 delta = dccp_delta_seqno(ap->dccpap_buf_ackno, |
681 | ackno); | |
7c657876 ACM |
682 | |
683 | /* | |
7690af3f ACM |
684 | * Look if the state of this packet is the same as the |
685 | * previous ackno and if so if we can bump the head len. | |
7c657876 ACM |
686 | */ |
687 | if (delta == 1 && | |
688 | dccp_ackpkts_state(ap, ap->dccpap_buf_head) == state && | |
7690af3f ACM |
689 | (dccp_ackpkts_len(ap, ap->dccpap_buf_head) < |
690 | DCCP_ACKPKTS_LEN_MASK)) | |
7c657876 ACM |
691 | ap->dccpap_buf[ap->dccpap_buf_head]++; |
692 | else if (dccp_ackpkts_set_buf_head_state(ap, delta, state)) | |
693 | return -ENOBUFS; | |
694 | } else { | |
695 | /* | |
696 | * A.1.2. Old Packets | |
697 | * | |
7690af3f ACM |
698 | * When a packet with Sequence Number S arrives, and |
699 | * S <= buf_ackno, the HC-Receiver will scan the table | |
700 | * for the byte corresponding to S. (Indexing structures | |
701 | * could reduce the complexity of this scan.) | |
7c657876 ACM |
702 | */ |
703 | u64 delta = dccp_delta_seqno(ackno, ap->dccpap_buf_ackno); | |
704 | unsigned int index = ap->dccpap_buf_head; | |
705 | ||
706 | while (1) { | |
707 | const u8 len = dccp_ackpkts_len(ap, index); | |
708 | const u8 state = dccp_ackpkts_state(ap, index); | |
709 | /* | |
7690af3f ACM |
710 | * valid packets not yet in dccpap_buf have a reserved |
711 | * entry, with a len equal to 0. | |
7c657876 ACM |
712 | */ |
713 | if (state == DCCP_ACKPKTS_STATE_NOT_RECEIVED && | |
7690af3f ACM |
714 | len == 0 && delta == 0) { /* Found our |
715 | reserved seat! */ | |
f6ccf554 DM |
716 | dccp_pr_debug("Found %llu reserved seat!\n", |
717 | (unsigned long long) ackno); | |
7c657876 ACM |
718 | ap->dccpap_buf[index] = state; |
719 | goto out; | |
720 | } | |
721 | /* len == 0 means one packet */ | |
722 | if (delta < len + 1) | |
723 | goto out_duplicate; | |
724 | ||
725 | delta -= len + 1; | |
726 | if (++index == ap->dccpap_buf_len) | |
727 | index = 0; | |
728 | } | |
729 | } | |
730 | ||
731 | ap->dccpap_buf_ackno = ackno; | |
b0e56780 | 732 | dccp_timestamp(sk, &ap->dccpap_time); |
7c657876 ACM |
733 | out: |
734 | dccp_pr_debug(""); | |
735 | dccp_ackpkts_print(ap); | |
736 | return 0; | |
737 | ||
738 | out_duplicate: | |
739 | /* Duplicate packet */ | |
7690af3f ACM |
740 | dccp_pr_debug("Received a dup or already considered lost " |
741 | "packet: %llu\n", (unsigned long long) ackno); | |
7c657876 ACM |
742 | return -EILSEQ; |
743 | } | |
744 | ||
725ba8ee | 745 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
746 | void dccp_ackvector_print(const u64 ackno, const unsigned char *vector, |
747 | int len) | |
7c657876 ACM |
748 | { |
749 | if (!dccp_debug) | |
750 | return; | |
751 | ||
f6ccf554 DM |
752 | printk("ACK vector len=%d, ackno=%llu |", len, |
753 | (unsigned long long) ackno); | |
7c657876 ACM |
754 | |
755 | while (len--) { | |
756 | const u8 state = (*vector & DCCP_ACKPKTS_STATE_MASK) >> 6; | |
757 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
758 | ||
759 | printk("%d,%d|", state, rl); | |
760 | ++vector; | |
761 | } | |
762 | ||
763 | printk("\n"); | |
764 | } | |
765 | ||
766 | void dccp_ackpkts_print(const struct dccp_ackpkts *ap) | |
767 | { | |
768 | dccp_ackvector_print(ap->dccpap_buf_ackno, | |
769 | ap->dccpap_buf + ap->dccpap_buf_head, | |
770 | ap->dccpap_buf_vector_len); | |
771 | } | |
772 | #endif | |
773 | ||
774 | static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts *ap) | |
775 | { | |
776 | /* | |
777 | * As we're keeping track of the ack vector size | |
778 | * (dccpap_buf_vector_len) and the sent ack vector size | |
779 | * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but | |
7690af3f ACM |
780 | * keep this code here as in the future we'll implement a vector of |
781 | * ack records, as suggested in draft-ietf-dccp-spec-11.txt | |
782 | * Appendix A. -acme | |
7c657876 ACM |
783 | */ |
784 | #if 0 | |
785 | ap->dccpap_buf_tail = ap->dccpap_ack_ptr + 1; | |
786 | if (ap->dccpap_buf_tail >= ap->dccpap_buf_len) | |
787 | ap->dccpap_buf_tail -= ap->dccpap_buf_len; | |
788 | #endif | |
789 | ap->dccpap_buf_vector_len -= ap->dccpap_ack_vector_len; | |
790 | } | |
791 | ||
792 | void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap, struct sock *sk, | |
793 | u64 ackno) | |
794 | { | |
795 | /* Check if we actually sent an ACK vector */ | |
796 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
797 | return; | |
798 | ||
799 | if (ackno == ap->dccpap_ack_seqno) { | |
725ba8ee | 800 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 801 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
802 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
803 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 804 | #endif |
7690af3f ACM |
805 | dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, " |
806 | "ack_ackno=%llu, ACKED!\n", | |
7c657876 | 807 | debug_prefix, 1, |
f6ccf554 DM |
808 | (unsigned long long) ap->dccpap_ack_seqno, |
809 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
810 | dccp_ackpkts_trow_away_ack_record(ap); |
811 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
812 | } | |
813 | } | |
814 | ||
815 | static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap, | |
816 | struct sock *sk, u64 ackno, | |
817 | const unsigned char len, | |
818 | const unsigned char *vector) | |
819 | { | |
820 | unsigned char i; | |
821 | ||
822 | /* Check if we actually sent an ACK vector */ | |
823 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
824 | return; | |
825 | /* | |
7690af3f ACM |
826 | * We're in the receiver half connection, so if the received an ACK |
827 | * vector ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're | |
828 | * not interested. | |
7c657876 ACM |
829 | * |
830 | * Extra explanation with example: | |
831 | * | |
832 | * if we received an ACK vector with ackno 50, it can only be acking | |
833 | * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent). | |
834 | */ | |
7690af3f | 835 | /* dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno); */ |
7c657876 | 836 | if (before48(ackno, ap->dccpap_ack_seqno)) { |
7690af3f | 837 | /* dccp_pr_debug_cat("yes\n"); */ |
7c657876 ACM |
838 | return; |
839 | } | |
7690af3f | 840 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
841 | |
842 | i = len; | |
843 | while (i--) { | |
844 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
845 | u64 ackno_end_rl; | |
846 | ||
847 | dccp_set_seqno(&ackno_end_rl, ackno - rl); | |
848 | ||
7690af3f ACM |
849 | /* |
850 | * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, | |
851 | * ap->dccpap_ack_seqno, ackno); | |
852 | */ | |
7c657876 | 853 | if (between48(ap->dccpap_ack_seqno, ackno_end_rl, ackno)) { |
7690af3f ACM |
854 | const u8 state = (*vector & |
855 | DCCP_ACKPKTS_STATE_MASK) >> 6; | |
856 | /* dccp_pr_debug_cat("yes\n"); */ | |
7c657876 ACM |
857 | |
858 | if (state != DCCP_ACKPKTS_STATE_NOT_RECEIVED) { | |
725ba8ee | 859 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 860 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
861 | const char *debug_prefix = |
862 | dp->dccps_role == DCCP_ROLE_CLIENT ? | |
863 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 864 | #endif |
7690af3f ACM |
865 | dccp_pr_debug("%sACK vector 0, len=%d, " |
866 | "ack_seqno=%llu, ack_ackno=%llu, " | |
867 | "ACKED!\n", | |
7c657876 | 868 | debug_prefix, len, |
f6ccf554 DM |
869 | (unsigned long long) |
870 | ap->dccpap_ack_seqno, | |
871 | (unsigned long long) | |
872 | ap->dccpap_ack_ackno); | |
7c657876 ACM |
873 | dccp_ackpkts_trow_away_ack_record(ap); |
874 | } | |
875 | /* | |
7690af3f ACM |
876 | * If dccpap_ack_seqno was not received, no problem |
877 | * we'll send another ACK vector. | |
7c657876 ACM |
878 | */ |
879 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
880 | break; | |
881 | } | |
7690af3f | 882 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
883 | |
884 | dccp_set_seqno(&ackno, ackno_end_rl - 1); | |
885 | ++vector; | |
886 | } | |
887 | } |