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; | |
1bc09869 | 143 | do_gettimeofday(&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; | |
b6ee3d4a | 364 | const u32 elapsed_time = timeval_now_delta(&ap->dccpap_time) / 10; |
7c657876 ACM |
365 | unsigned char *to, *from; |
366 | ||
367 | if (elapsed_time != 0) | |
368 | dccp_insert_option_elapsed_time(sk, skb, elapsed_time); | |
369 | ||
370 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
371 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to " |
372 | "insert ACK Vector!\n"); | |
7c657876 ACM |
373 | return; |
374 | } | |
375 | ||
376 | /* | |
377 | * XXX: now we have just one ack vector sent record, so | |
378 | * we have to wait for it to be cleared. | |
379 | * | |
380 | * Of course this is not acceptable, but this is just for | |
381 | * basic testing now. | |
382 | */ | |
383 | if (ap->dccpap_ack_seqno != DCCP_MAX_SEQNO + 1) | |
384 | return; | |
385 | ||
386 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
387 | ||
388 | to = skb_push(skb, len); | |
389 | *to++ = DCCPO_ACK_VECTOR_0; | |
390 | *to++ = len; | |
391 | ||
392 | len = ap->dccpap_buf_vector_len; | |
393 | from = ap->dccpap_buf + ap->dccpap_buf_head; | |
394 | ||
395 | /* Check if buf_head wraps */ | |
396 | if (ap->dccpap_buf_head + len > ap->dccpap_buf_len) { | |
7690af3f ACM |
397 | const unsigned int tailsize = (ap->dccpap_buf_len - |
398 | ap->dccpap_buf_head); | |
7c657876 ACM |
399 | |
400 | memcpy(to, from, tailsize); | |
401 | to += tailsize; | |
402 | len -= tailsize; | |
403 | from = ap->dccpap_buf; | |
404 | } | |
405 | ||
406 | memcpy(to, from, len); | |
407 | /* | |
408 | * From draft-ietf-dccp-spec-11.txt: | |
409 | * | |
410 | * For each acknowledgement it sends, the HC-Receiver will add an | |
411 | * acknowledgement record. ack_seqno will equal the HC-Receiver | |
412 | * sequence number it used for the ack packet; ack_ptr will equal | |
7690af3f ACM |
413 | * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will |
414 | * equal buf_nonce. | |
7c657876 ACM |
415 | * |
416 | * This implemention uses just one ack record for now. | |
417 | */ | |
418 | ap->dccpap_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
419 | ap->dccpap_ack_ptr = ap->dccpap_buf_head; | |
420 | ap->dccpap_ack_ackno = ap->dccpap_buf_ackno; | |
421 | ap->dccpap_ack_nonce = ap->dccpap_buf_nonce; | |
422 | ap->dccpap_ack_vector_len = ap->dccpap_buf_vector_len; | |
423 | ||
7690af3f ACM |
424 | dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, " |
425 | "ack_ackno=%llu\n", | |
7c657876 | 426 | debug_prefix, ap->dccpap_ack_vector_len, |
f6ccf554 DM |
427 | (unsigned long long) ap->dccpap_ack_seqno, |
428 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
429 | } |
430 | ||
d4b81ff7 | 431 | void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 432 | { |
1bc09869 IM |
433 | struct timeval tv; |
434 | u32 now; | |
435 | ||
436 | do_gettimeofday(&tv); | |
437 | now = (tv.tv_sec * USEC_PER_SEC + tv.tv_usec) / 10; | |
438 | /* yes this will overflow but that is the point as we want a | |
439 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
440 | ||
441 | now = htonl(now); | |
7c657876 ACM |
442 | dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
443 | } | |
444 | ||
d4b81ff7 ACM |
445 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
446 | ||
7690af3f ACM |
447 | static void dccp_insert_option_timestamp_echo(struct sock *sk, |
448 | struct sk_buff *skb) | |
7c657876 ACM |
449 | { |
450 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 451 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
452 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
453 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
454 | #endif |
455 | u32 tstamp_echo; | |
b6ee3d4a ACM |
456 | const u32 elapsed_time = |
457 | timeval_now_delta(&dp->dccps_timestamp_time) / 10; | |
7c657876 ACM |
458 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
459 | const int len = 6 + elapsed_time_len; | |
460 | unsigned char *to; | |
461 | ||
462 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
463 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert " |
464 | "timestamp echo!\n"); | |
7c657876 ACM |
465 | return; |
466 | } | |
467 | ||
468 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
469 | ||
470 | to = skb_push(skb, len); | |
471 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
472 | *to++ = len; | |
473 | ||
474 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
475 | memcpy(to, &tstamp_echo, 4); | |
476 | to += 4; | |
1bc09869 IM |
477 | |
478 | if (elapsed_time_len == 2) { | |
479 | const u16 var16 = htons((u16)elapsed_time); | |
480 | memcpy(to, &var16, 2); | |
481 | } else if (elapsed_time_len == 4) { | |
482 | const u32 var32 = htonl(elapsed_time); | |
483 | memcpy(to, &var32, 4); | |
484 | } | |
7c657876 ACM |
485 | |
486 | dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n", | |
487 | debug_prefix, dp->dccps_timestamp_echo, | |
f6ccf554 DM |
488 | len, |
489 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); | |
7c657876 ACM |
490 | |
491 | dp->dccps_timestamp_echo = 0; | |
1bc09869 IM |
492 | dp->dccps_timestamp_time.tv_sec = 0; |
493 | dp->dccps_timestamp_time.tv_usec = 0; | |
7c657876 ACM |
494 | } |
495 | ||
496 | void dccp_insert_options(struct sock *sk, struct sk_buff *skb) | |
497 | { | |
498 | struct dccp_sock *dp = dccp_sk(sk); | |
499 | ||
500 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
501 | ||
502 | if (dp->dccps_options.dccpo_send_ndp_count) | |
503 | dccp_insert_option_ndp(sk, skb); | |
504 | ||
505 | if (!dccp_packet_without_ack(skb)) { | |
506 | if (dp->dccps_options.dccpo_send_ack_vector && | |
7690af3f ACM |
507 | (dp->dccps_hc_rx_ackpkts->dccpap_buf_ackno != |
508 | DCCP_MAX_SEQNO + 1)) | |
7c657876 | 509 | dccp_insert_option_ack_vector(sk, skb); |
7c657876 ACM |
510 | if (dp->dccps_timestamp_echo != 0) |
511 | dccp_insert_option_timestamp_echo(sk, skb); | |
512 | } | |
513 | ||
507d37cf ACM |
514 | if (dp->dccps_hc_rx_insert_options) { |
515 | ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb); | |
516 | dp->dccps_hc_rx_insert_options = 0; | |
517 | } | |
518 | if (dp->dccps_hc_tx_insert_options) { | |
519 | ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb); | |
520 | dp->dccps_hc_tx_insert_options = 0; | |
521 | } | |
7c657876 ACM |
522 | |
523 | /* XXX: insert other options when appropriate */ | |
524 | ||
525 | if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { | |
526 | /* The length of all options has to be a multiple of 4 */ | |
527 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
528 | ||
529 | if (padding != 0) { | |
530 | padding = 4 - padding; | |
531 | memset(skb_push(skb, padding), 0, padding); | |
532 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
533 | } | |
534 | } | |
535 | } | |
536 | ||
a1d3a355 ACM |
537 | struct dccp_ackpkts *dccp_ackpkts_alloc(const unsigned int len, |
538 | const unsigned int __nocast priority) | |
7c657876 ACM |
539 | { |
540 | struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority); | |
541 | ||
542 | if (ap != NULL) { | |
725ba8ee | 543 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
544 | memset(ap->dccpap_buf, 0xFF, len); |
545 | #endif | |
7690af3f ACM |
546 | ap->dccpap_buf_len = len; |
547 | ap->dccpap_buf_head = | |
548 | ap->dccpap_buf_tail = | |
549 | ap->dccpap_buf_len - 1; | |
550 | ap->dccpap_buf_ackno = | |
551 | ap->dccpap_ack_ackno = | |
552 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
553 | ap->dccpap_buf_nonce = ap->dccpap_buf_nonce = 0; | |
554 | ap->dccpap_ack_ptr = 0; | |
1bc09869 IM |
555 | ap->dccpap_time.tv_sec = 0; |
556 | ap->dccpap_time.tv_usec = 0; | |
7c657876 ACM |
557 | ap->dccpap_buf_vector_len = ap->dccpap_ack_vector_len = 0; |
558 | } | |
559 | ||
560 | return ap; | |
561 | } | |
562 | ||
563 | void dccp_ackpkts_free(struct dccp_ackpkts *ap) | |
564 | { | |
565 | if (ap != NULL) { | |
725ba8ee | 566 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
567 | memset(ap, 0xFF, sizeof(*ap) + ap->dccpap_buf_len); |
568 | #endif | |
569 | kfree(ap); | |
570 | } | |
571 | } | |
572 | ||
573 | static inline u8 dccp_ackpkts_state(const struct dccp_ackpkts *ap, | |
574 | const unsigned int index) | |
575 | { | |
576 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_STATE_MASK; | |
577 | } | |
578 | ||
579 | static inline u8 dccp_ackpkts_len(const struct dccp_ackpkts *ap, | |
580 | const unsigned int index) | |
581 | { | |
582 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_LEN_MASK; | |
583 | } | |
584 | ||
585 | /* | |
586 | * If several packets are missing, the HC-Receiver may prefer to enter multiple | |
587 | * bytes with run length 0, rather than a single byte with a larger run length; | |
588 | * this simplifies table updates if one of the missing packets arrives. | |
589 | */ | |
590 | static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap, | |
591 | const unsigned int packets, | |
592 | const unsigned char state) | |
593 | { | |
594 | unsigned int gap; | |
595 | signed long new_head; | |
596 | ||
597 | if (ap->dccpap_buf_vector_len + packets > ap->dccpap_buf_len) | |
598 | return -ENOBUFS; | |
599 | ||
600 | gap = packets - 1; | |
601 | new_head = ap->dccpap_buf_head - packets; | |
602 | ||
603 | if (new_head < 0) { | |
604 | if (gap > 0) { | |
605 | memset(ap->dccpap_buf, DCCP_ACKPKTS_STATE_NOT_RECEIVED, | |
606 | gap + new_head + 1); | |
607 | gap = -new_head; | |
608 | } | |
609 | new_head += ap->dccpap_buf_len; | |
610 | } | |
611 | ||
612 | ap->dccpap_buf_head = new_head; | |
613 | ||
614 | if (gap > 0) | |
615 | memset(ap->dccpap_buf + ap->dccpap_buf_head + 1, | |
616 | DCCP_ACKPKTS_STATE_NOT_RECEIVED, gap); | |
617 | ||
618 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
619 | ap->dccpap_buf_vector_len += packets; | |
620 | return 0; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Implements the draft-ietf-dccp-spec-11.txt Appendix A | |
625 | */ | |
626 | int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state) | |
627 | { | |
628 | /* | |
629 | * Check at the right places if the buffer is full, if it is, tell the | |
630 | * caller to start dropping packets till the HC-Sender acks our ACK | |
631 | * vectors, when we will free up space in dccpap_buf. | |
632 | * | |
633 | * We may well decide to do buffer compression, etc, but for now lets | |
634 | * just drop. | |
635 | * | |
636 | * From Appendix A: | |
637 | * | |
7690af3f ACM |
638 | * Of course, the circular buffer may overflow, either when the |
639 | * HC-Sender is sending data at a very high rate, when the | |
640 | * HC-Receiver's acknowledgements are not reaching the HC-Sender, | |
641 | * or when the HC-Sender is forgetting to acknowledge those acks | |
642 | * (so the HC-Receiver is unable to clean up old state). In this | |
643 | * case, the HC-Receiver should either compress the buffer (by | |
644 | * increasing run lengths when possible), transfer its state to | |
645 | * a larger buffer, or, as a last resort, drop all received | |
646 | * packets, without processing them whatsoever, until its buffer | |
647 | * shrinks again. | |
7c657876 ACM |
648 | */ |
649 | ||
650 | /* See if this is the first ackno being inserted */ | |
651 | if (ap->dccpap_buf_vector_len == 0) { | |
652 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
653 | ap->dccpap_buf_vector_len = 1; | |
654 | } else if (after48(ackno, ap->dccpap_buf_ackno)) { | |
7690af3f ACM |
655 | const u64 delta = dccp_delta_seqno(ap->dccpap_buf_ackno, |
656 | ackno); | |
7c657876 ACM |
657 | |
658 | /* | |
7690af3f ACM |
659 | * Look if the state of this packet is the same as the |
660 | * previous ackno and if so if we can bump the head len. | |
7c657876 ACM |
661 | */ |
662 | if (delta == 1 && | |
663 | dccp_ackpkts_state(ap, ap->dccpap_buf_head) == state && | |
7690af3f ACM |
664 | (dccp_ackpkts_len(ap, ap->dccpap_buf_head) < |
665 | DCCP_ACKPKTS_LEN_MASK)) | |
7c657876 ACM |
666 | ap->dccpap_buf[ap->dccpap_buf_head]++; |
667 | else if (dccp_ackpkts_set_buf_head_state(ap, delta, state)) | |
668 | return -ENOBUFS; | |
669 | } else { | |
670 | /* | |
671 | * A.1.2. Old Packets | |
672 | * | |
7690af3f ACM |
673 | * When a packet with Sequence Number S arrives, and |
674 | * S <= buf_ackno, the HC-Receiver will scan the table | |
675 | * for the byte corresponding to S. (Indexing structures | |
676 | * could reduce the complexity of this scan.) | |
7c657876 ACM |
677 | */ |
678 | u64 delta = dccp_delta_seqno(ackno, ap->dccpap_buf_ackno); | |
679 | unsigned int index = ap->dccpap_buf_head; | |
680 | ||
681 | while (1) { | |
682 | const u8 len = dccp_ackpkts_len(ap, index); | |
683 | const u8 state = dccp_ackpkts_state(ap, index); | |
684 | /* | |
7690af3f ACM |
685 | * valid packets not yet in dccpap_buf have a reserved |
686 | * entry, with a len equal to 0. | |
7c657876 ACM |
687 | */ |
688 | if (state == DCCP_ACKPKTS_STATE_NOT_RECEIVED && | |
7690af3f ACM |
689 | len == 0 && delta == 0) { /* Found our |
690 | reserved seat! */ | |
f6ccf554 DM |
691 | dccp_pr_debug("Found %llu reserved seat!\n", |
692 | (unsigned long long) ackno); | |
7c657876 ACM |
693 | ap->dccpap_buf[index] = state; |
694 | goto out; | |
695 | } | |
696 | /* len == 0 means one packet */ | |
697 | if (delta < len + 1) | |
698 | goto out_duplicate; | |
699 | ||
700 | delta -= len + 1; | |
701 | if (++index == ap->dccpap_buf_len) | |
702 | index = 0; | |
703 | } | |
704 | } | |
705 | ||
706 | ap->dccpap_buf_ackno = ackno; | |
1bc09869 | 707 | do_gettimeofday(&ap->dccpap_time); |
7c657876 ACM |
708 | out: |
709 | dccp_pr_debug(""); | |
710 | dccp_ackpkts_print(ap); | |
711 | return 0; | |
712 | ||
713 | out_duplicate: | |
714 | /* Duplicate packet */ | |
7690af3f ACM |
715 | dccp_pr_debug("Received a dup or already considered lost " |
716 | "packet: %llu\n", (unsigned long long) ackno); | |
7c657876 ACM |
717 | return -EILSEQ; |
718 | } | |
719 | ||
725ba8ee | 720 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
721 | void dccp_ackvector_print(const u64 ackno, const unsigned char *vector, |
722 | int len) | |
7c657876 ACM |
723 | { |
724 | if (!dccp_debug) | |
725 | return; | |
726 | ||
f6ccf554 DM |
727 | printk("ACK vector len=%d, ackno=%llu |", len, |
728 | (unsigned long long) ackno); | |
7c657876 ACM |
729 | |
730 | while (len--) { | |
731 | const u8 state = (*vector & DCCP_ACKPKTS_STATE_MASK) >> 6; | |
732 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
733 | ||
734 | printk("%d,%d|", state, rl); | |
735 | ++vector; | |
736 | } | |
737 | ||
738 | printk("\n"); | |
739 | } | |
740 | ||
741 | void dccp_ackpkts_print(const struct dccp_ackpkts *ap) | |
742 | { | |
743 | dccp_ackvector_print(ap->dccpap_buf_ackno, | |
744 | ap->dccpap_buf + ap->dccpap_buf_head, | |
745 | ap->dccpap_buf_vector_len); | |
746 | } | |
747 | #endif | |
748 | ||
749 | static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts *ap) | |
750 | { | |
751 | /* | |
752 | * As we're keeping track of the ack vector size | |
753 | * (dccpap_buf_vector_len) and the sent ack vector size | |
754 | * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but | |
7690af3f ACM |
755 | * keep this code here as in the future we'll implement a vector of |
756 | * ack records, as suggested in draft-ietf-dccp-spec-11.txt | |
757 | * Appendix A. -acme | |
7c657876 ACM |
758 | */ |
759 | #if 0 | |
760 | ap->dccpap_buf_tail = ap->dccpap_ack_ptr + 1; | |
761 | if (ap->dccpap_buf_tail >= ap->dccpap_buf_len) | |
762 | ap->dccpap_buf_tail -= ap->dccpap_buf_len; | |
763 | #endif | |
764 | ap->dccpap_buf_vector_len -= ap->dccpap_ack_vector_len; | |
765 | } | |
766 | ||
767 | void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap, struct sock *sk, | |
768 | u64 ackno) | |
769 | { | |
770 | /* Check if we actually sent an ACK vector */ | |
771 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
772 | return; | |
773 | ||
774 | if (ackno == ap->dccpap_ack_seqno) { | |
725ba8ee | 775 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 776 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
777 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
778 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 779 | #endif |
7690af3f ACM |
780 | dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, " |
781 | "ack_ackno=%llu, ACKED!\n", | |
7c657876 | 782 | debug_prefix, 1, |
f6ccf554 DM |
783 | (unsigned long long) ap->dccpap_ack_seqno, |
784 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
785 | dccp_ackpkts_trow_away_ack_record(ap); |
786 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
787 | } | |
788 | } | |
789 | ||
790 | static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap, | |
791 | struct sock *sk, u64 ackno, | |
792 | const unsigned char len, | |
793 | const unsigned char *vector) | |
794 | { | |
795 | unsigned char i; | |
796 | ||
797 | /* Check if we actually sent an ACK vector */ | |
798 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
799 | return; | |
800 | /* | |
7690af3f ACM |
801 | * We're in the receiver half connection, so if the received an ACK |
802 | * vector ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're | |
803 | * not interested. | |
7c657876 ACM |
804 | * |
805 | * Extra explanation with example: | |
806 | * | |
807 | * if we received an ACK vector with ackno 50, it can only be acking | |
808 | * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent). | |
809 | */ | |
7690af3f | 810 | /* dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno); */ |
7c657876 | 811 | if (before48(ackno, ap->dccpap_ack_seqno)) { |
7690af3f | 812 | /* dccp_pr_debug_cat("yes\n"); */ |
7c657876 ACM |
813 | return; |
814 | } | |
7690af3f | 815 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
816 | |
817 | i = len; | |
818 | while (i--) { | |
819 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
820 | u64 ackno_end_rl; | |
821 | ||
822 | dccp_set_seqno(&ackno_end_rl, ackno - rl); | |
823 | ||
7690af3f ACM |
824 | /* |
825 | * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, | |
826 | * ap->dccpap_ack_seqno, ackno); | |
827 | */ | |
7c657876 | 828 | if (between48(ap->dccpap_ack_seqno, ackno_end_rl, ackno)) { |
7690af3f ACM |
829 | const u8 state = (*vector & |
830 | DCCP_ACKPKTS_STATE_MASK) >> 6; | |
831 | /* dccp_pr_debug_cat("yes\n"); */ | |
7c657876 ACM |
832 | |
833 | if (state != DCCP_ACKPKTS_STATE_NOT_RECEIVED) { | |
725ba8ee | 834 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 835 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
836 | const char *debug_prefix = |
837 | dp->dccps_role == DCCP_ROLE_CLIENT ? | |
838 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 839 | #endif |
7690af3f ACM |
840 | dccp_pr_debug("%sACK vector 0, len=%d, " |
841 | "ack_seqno=%llu, ack_ackno=%llu, " | |
842 | "ACKED!\n", | |
7c657876 | 843 | debug_prefix, len, |
f6ccf554 DM |
844 | (unsigned long long) |
845 | ap->dccpap_ack_seqno, | |
846 | (unsigned long long) | |
847 | ap->dccpap_ack_ackno); | |
7c657876 ACM |
848 | dccp_ackpkts_trow_away_ack_record(ap); |
849 | } | |
850 | /* | |
7690af3f ACM |
851 | * If dccpap_ack_seqno was not received, no problem |
852 | * we'll send another ACK vector. | |
7c657876 ACM |
853 | */ |
854 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
855 | break; | |
856 | } | |
7690af3f | 857 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
858 | |
859 | dccp_set_seqno(&ackno, ackno_end_rl - 1); | |
860 | ++vector; | |
861 | } | |
862 | } |