Commit | Line | Data |
---|---|---|
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> | |
e6bccd35 | 7 | * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.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 | */ | |
7c657876 ACM |
14 | #include <linux/dccp.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/types.h> | |
76fd1e87 | 17 | #include <asm/unaligned.h> |
7c657876 ACM |
18 | #include <linux/kernel.h> |
19 | #include <linux/skbuff.h> | |
20 | ||
ae31c339 | 21 | #include "ackvec.h" |
7c657876 ACM |
22 | #include "ccid.h" |
23 | #include "dccp.h" | |
afe00251 | 24 | #include "feat.h" |
7c657876 | 25 | |
b9aaac1c | 26 | u64 dccp_decode_value_var(const u8 *bf, const u8 len) |
7c657876 | 27 | { |
b9aaac1c | 28 | u64 value = 0; |
7c657876 | 29 | |
b9aaac1c GR |
30 | if (len >= DCCP_OPTVAL_MAXLEN) |
31 | value += ((u64)*bf++) << 40; | |
32 | if (len > 4) | |
33 | value += ((u64)*bf++) << 32; | |
7c657876 | 34 | if (len > 3) |
b9aaac1c | 35 | value += ((u64)*bf++) << 24; |
7c657876 | 36 | if (len > 2) |
b9aaac1c | 37 | value += ((u64)*bf++) << 16; |
7c657876 | 38 | if (len > 1) |
b9aaac1c | 39 | value += ((u64)*bf++) << 8; |
7c657876 ACM |
40 | if (len > 0) |
41 | value += *bf; | |
42 | ||
43 | return value; | |
44 | } | |
45 | ||
8b819412 GR |
46 | /** |
47 | * dccp_parse_options - Parse DCCP options present in @skb | |
48 | * @sk: client|server|listening dccp socket (when @dreq != NULL) | |
49 | * @dreq: request socket to use during connection setup, or NULL | |
50 | */ | |
51 | int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, | |
52 | struct sk_buff *skb) | |
7c657876 ACM |
53 | { |
54 | struct dccp_sock *dp = dccp_sk(sk); | |
7c657876 ACM |
55 | const struct dccp_hdr *dh = dccp_hdr(skb); |
56 | const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; | |
57 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
58 | unsigned char *opt_ptr = options; | |
7690af3f ACM |
59 | const unsigned char *opt_end = (unsigned char *)dh + |
60 | (dh->dccph_doff * 4); | |
7c657876 ACM |
61 | struct dccp_options_received *opt_recv = &dp->dccps_options_received; |
62 | unsigned char opt, len; | |
63 | unsigned char *value; | |
1c14ac0a | 64 | u32 elapsed_time; |
76fd1e87 | 65 | __be32 opt_val; |
afe00251 AB |
66 | int rc; |
67 | int mandatory = 0; | |
7c657876 ACM |
68 | |
69 | memset(opt_recv, 0, sizeof(*opt_recv)); | |
70 | ||
fb950496 | 71 | opt = len = 0; |
7c657876 ACM |
72 | while (opt_ptr != opt_end) { |
73 | opt = *opt_ptr++; | |
74 | len = 0; | |
75 | value = NULL; | |
76 | ||
77 | /* Check if this isn't a single byte option */ | |
78 | if (opt > DCCPO_MAX_RESERVED) { | |
79 | if (opt_ptr == opt_end) | |
faf61c33 | 80 | goto out_nonsensical_length; |
7c657876 ACM |
81 | |
82 | len = *opt_ptr++; | |
faf61c33 GR |
83 | if (len < 2) |
84 | goto out_nonsensical_length; | |
7c657876 ACM |
85 | /* |
86 | * Remove the type and len fields, leaving | |
87 | * just the value size | |
88 | */ | |
89 | len -= 2; | |
90 | value = opt_ptr; | |
91 | opt_ptr += len; | |
92 | ||
93 | if (opt_ptr > opt_end) | |
faf61c33 | 94 | goto out_nonsensical_length; |
7c657876 ACM |
95 | } |
96 | ||
8b819412 | 97 | /* |
8b819412 GR |
98 | * CCID-specific options are ignored during connection setup, as |
99 | * negotiation may still be in progress (see RFC 4340, 10.3). | |
65907a43 | 100 | * The same applies to Ack Vectors, as these depend on the CCID. |
8b819412 | 101 | */ |
f10ecaee | 102 | if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC || |
65907a43 | 103 | opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) |
8b819412 GR |
104 | goto ignore_option; |
105 | ||
7c657876 ACM |
106 | switch (opt) { |
107 | case DCCPO_PADDING: | |
108 | break; | |
afe00251 AB |
109 | case DCCPO_MANDATORY: |
110 | if (mandatory) | |
111 | goto out_invalid_option; | |
6df9424a ACM |
112 | if (pkt_type != DCCP_PKT_DATA) |
113 | mandatory = 1; | |
afe00251 | 114 | break; |
7c657876 | 115 | case DCCPO_NDP_COUNT: |
5b5d0e70 | 116 | if (len > 6) |
7c657876 ACM |
117 | goto out_invalid_option; |
118 | ||
119 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
5b5d0e70 GR |
120 | dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), |
121 | (unsigned long long)opt_recv->dccpor_ndp); | |
7c657876 | 122 | break; |
d2150b7b GR |
123 | case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: |
124 | if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ | |
cf86314c | 125 | break; |
5a146b97 GR |
126 | rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, |
127 | *value, value + 1, len - 1); | |
128 | if (rc) | |
129 | goto out_featneg_failed; | |
afe00251 | 130 | break; |
7c657876 | 131 | case DCCPO_ACK_VECTOR_0: |
ae31c339 | 132 | case DCCPO_ACK_VECTOR_1: |
c86ab2b6 | 133 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ |
e5a6de91 | 134 | break; |
68b1de15 GR |
135 | dccp_pr_debug("%s Ack Vector (len=%u)\n", dccp_role(sk), |
136 | len); | |
7c657876 ACM |
137 | break; |
138 | case DCCPO_TIMESTAMP: | |
139 | if (len != 4) | |
140 | goto out_invalid_option; | |
b4d4f7c7 GR |
141 | /* |
142 | * RFC 4340 13.1: "The precise time corresponding to | |
143 | * Timestamp Value zero is not specified". We use | |
144 | * zero to indicate absence of a meaningful timestamp. | |
145 | */ | |
76fd1e87 | 146 | opt_val = get_unaligned((__be32 *)value); |
b4d4f7c7 GR |
147 | if (unlikely(opt_val == 0)) { |
148 | DCCP_WARN("Timestamp with zero value\n"); | |
149 | break; | |
150 | } | |
7c657876 | 151 | |
b4d4f7c7 GR |
152 | if (dreq != NULL) { |
153 | dreq->dreq_timestamp_echo = ntohl(opt_val); | |
154 | dreq->dreq_timestamp_time = dccp_timestamp(); | |
155 | } else { | |
156 | opt_recv->dccpor_timestamp = | |
157 | dp->dccps_timestamp_echo = ntohl(opt_val); | |
158 | dp->dccps_timestamp_time = dccp_timestamp(); | |
159 | } | |
09dbc389 | 160 | dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
b4d4f7c7 | 161 | dccp_role(sk), ntohl(opt_val), |
f6ccf554 | 162 | (unsigned long long) |
7c657876 | 163 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
2975abd2 GR |
164 | /* schedule an Ack in case this sender is quiescent */ |
165 | inet_csk_schedule_ack(sk); | |
7c657876 ACM |
166 | break; |
167 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 168 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
169 | goto out_invalid_option; |
170 | ||
76fd1e87 GR |
171 | opt_val = get_unaligned((__be32 *)value); |
172 | opt_recv->dccpor_timestamp_echo = ntohl(opt_val); | |
7c657876 | 173 | |
09dbc389 | 174 | dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
f73f7097 | 175 | "ackno=%llu", dccp_role(sk), |
7690af3f | 176 | opt_recv->dccpor_timestamp_echo, |
f6ccf554 DM |
177 | len + 2, |
178 | (unsigned long long) | |
1bc09869 IM |
179 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
180 | ||
76fd1e87 | 181 | value += 4; |
1bc09869 | 182 | |
76fd1e87 | 183 | if (len == 4) { /* no elapsed time included */ |
f73f7097 | 184 | dccp_pr_debug_cat("\n"); |
1c14ac0a | 185 | break; |
f73f7097 | 186 | } |
1c14ac0a | 187 | |
76fd1e87 GR |
188 | if (len == 6) { /* 2-byte elapsed time */ |
189 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
190 | elapsed_time = ntohs(opt_val2); | |
191 | } else { /* 4-byte elapsed time */ | |
192 | opt_val = get_unaligned((__be32 *)value); | |
193 | elapsed_time = ntohl(opt_val); | |
194 | } | |
1c14ac0a | 195 | |
dcad856f | 196 | dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); |
f73f7097 | 197 | |
1c14ac0a ACM |
198 | /* Give precedence to the biggest ELAPSED_TIME */ |
199 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
200 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
201 | break; |
202 | case DCCPO_ELAPSED_TIME: | |
c86ab2b6 GR |
203 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ |
204 | break; | |
1bc09869 | 205 | |
76fd1e87 GR |
206 | if (len == 2) { |
207 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
208 | elapsed_time = ntohs(opt_val2); | |
c86ab2b6 | 209 | } else if (len == 4) { |
76fd1e87 GR |
210 | opt_val = get_unaligned((__be32 *)value); |
211 | elapsed_time = ntohl(opt_val); | |
c86ab2b6 GR |
212 | } else { |
213 | goto out_invalid_option; | |
76fd1e87 | 214 | } |
1c14ac0a ACM |
215 | |
216 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
217 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 218 | |
09dbc389 GR |
219 | dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
220 | dccp_role(sk), elapsed_time); | |
7c657876 | 221 | break; |
f10ecaee | 222 | case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC: |
7690af3f | 223 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
3306c781 | 224 | pkt_type, opt, value, len)) |
7c657876 | 225 | goto out_invalid_option; |
7c657876 | 226 | break; |
f10ecaee | 227 | case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC: |
7690af3f | 228 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
3306c781 | 229 | pkt_type, opt, value, len)) |
7c657876 | 230 | goto out_invalid_option; |
7c657876 ACM |
231 | break; |
232 | default: | |
59348b19 GR |
233 | DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
234 | "implemented, ignoring", sk, opt, len); | |
7c657876 | 235 | break; |
c9eaf173 | 236 | } |
8b819412 | 237 | ignore_option: |
afe00251 AB |
238 | if (opt != DCCPO_MANDATORY) |
239 | mandatory = 0; | |
7c657876 ACM |
240 | } |
241 | ||
6df9424a ACM |
242 | /* mandatory was the last byte in option list -> reset connection */ |
243 | if (mandatory) | |
244 | goto out_invalid_option; | |
245 | ||
faf61c33 GR |
246 | out_nonsensical_length: |
247 | /* RFC 4340, 5.8: ignore option and all remaining option space */ | |
7c657876 ACM |
248 | return 0; |
249 | ||
250 | out_invalid_option: | |
251 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
5a146b97 GR |
252 | rc = DCCP_RESET_CODE_OPTION_ERROR; |
253 | out_featneg_failed: | |
254 | DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); | |
255 | DCCP_SKB_CB(skb)->dccpd_reset_code = rc; | |
eac7726b GR |
256 | DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; |
257 | DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; | |
258 | DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; | |
7c657876 ACM |
259 | return -1; |
260 | } | |
261 | ||
b61fafc4 ACM |
262 | EXPORT_SYMBOL_GPL(dccp_parse_options); |
263 | ||
b9aaac1c | 264 | void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) |
7c657876 | 265 | { |
b9aaac1c GR |
266 | if (len >= DCCP_OPTVAL_MAXLEN) |
267 | *to++ = (value & 0xFF0000000000ull) >> 40; | |
268 | if (len > 4) | |
269 | *to++ = (value & 0xFF00000000ull) >> 32; | |
7c657876 ACM |
270 | if (len > 3) |
271 | *to++ = (value & 0xFF000000) >> 24; | |
272 | if (len > 2) | |
273 | *to++ = (value & 0xFF0000) >> 16; | |
274 | if (len > 1) | |
275 | *to++ = (value & 0xFF00) >> 8; | |
276 | if (len > 0) | |
277 | *to++ = (value & 0xFF); | |
278 | } | |
279 | ||
5b5d0e70 | 280 | static inline u8 dccp_ndp_len(const u64 ndp) |
7c657876 | 281 | { |
5b5d0e70 GR |
282 | if (likely(ndp <= 0xFF)) |
283 | return 1; | |
284 | return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); | |
7c657876 ACM |
285 | } |
286 | ||
2d0817d1 | 287 | int dccp_insert_option(struct sock *sk, struct sk_buff *skb, |
7c657876 ACM |
288 | const unsigned char option, |
289 | const void *value, const unsigned char len) | |
290 | { | |
291 | unsigned char *to; | |
292 | ||
2d0817d1 ACM |
293 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
294 | return -1; | |
7c657876 ACM |
295 | |
296 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
297 | ||
298 | to = skb_push(skb, len + 2); | |
299 | *to++ = option; | |
300 | *to++ = len + 2; | |
301 | ||
302 | memcpy(to, value, len); | |
2d0817d1 | 303 | return 0; |
7c657876 ACM |
304 | } |
305 | ||
306 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
307 | ||
2d0817d1 | 308 | static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
309 | { |
310 | struct dccp_sock *dp = dccp_sk(sk); | |
5b5d0e70 | 311 | u64 ndp = dp->dccps_ndp_count; |
7c657876 ACM |
312 | |
313 | if (dccp_non_data_packet(skb)) | |
314 | ++dp->dccps_ndp_count; | |
315 | else | |
316 | dp->dccps_ndp_count = 0; | |
317 | ||
318 | if (ndp > 0) { | |
319 | unsigned char *ptr; | |
320 | const int ndp_len = dccp_ndp_len(ndp); | |
321 | const int len = ndp_len + 2; | |
322 | ||
323 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
2d0817d1 | 324 | return -1; |
7c657876 ACM |
325 | |
326 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
327 | ||
328 | ptr = skb_push(skb, len); | |
329 | *ptr++ = DCCPO_NDP_COUNT; | |
330 | *ptr++ = len; | |
331 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
332 | } | |
2d0817d1 ACM |
333 | |
334 | return 0; | |
7c657876 ACM |
335 | } |
336 | ||
337 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
338 | { | |
b1c9fe7b | 339 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
340 | } |
341 | ||
2d0817d1 ACM |
342 | int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb, |
343 | u32 elapsed_time) | |
7c657876 | 344 | { |
7c657876 ACM |
345 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
346 | const int len = 2 + elapsed_time_len; | |
347 | unsigned char *to; | |
348 | ||
1bc09869 | 349 | if (elapsed_time_len == 0) |
2d0817d1 | 350 | return 0; |
7c657876 | 351 | |
2d0817d1 ACM |
352 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
353 | return -1; | |
7c657876 ACM |
354 | |
355 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
356 | ||
357 | to = skb_push(skb, len); | |
358 | *to++ = DCCPO_ELAPSED_TIME; | |
359 | *to++ = len; | |
360 | ||
1bc09869 | 361 | if (elapsed_time_len == 2) { |
60fe62e7 | 362 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
363 | memcpy(to, &var16, 2); |
364 | } else { | |
60fe62e7 | 365 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
366 | memcpy(to, &var32, 4); |
367 | } | |
7c657876 | 368 | |
2d0817d1 | 369 | return 0; |
7c657876 ACM |
370 | } |
371 | ||
d4b81ff7 | 372 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 | 373 | |
2d0817d1 | 374 | int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 375 | { |
4c70f383 | 376 | __be32 now = htonl(dccp_timestamp()); |
1bc09869 IM |
377 | /* yes this will overflow but that is the point as we want a |
378 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
379 | ||
2d0817d1 | 380 | return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
7c657876 ACM |
381 | } |
382 | ||
d4b81ff7 ACM |
383 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
384 | ||
b4d4f7c7 GR |
385 | static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, |
386 | struct dccp_request_sock *dreq, | |
2d0817d1 | 387 | struct sk_buff *skb) |
7c657876 | 388 | { |
60fe62e7 | 389 | __be32 tstamp_echo; |
7c657876 | 390 | unsigned char *to; |
b4d4f7c7 GR |
391 | u32 elapsed_time, elapsed_time_len, len; |
392 | ||
393 | if (dreq != NULL) { | |
394 | elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; | |
395 | tstamp_echo = htonl(dreq->dreq_timestamp_echo); | |
396 | dreq->dreq_timestamp_echo = 0; | |
397 | } else { | |
398 | elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; | |
399 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
400 | dp->dccps_timestamp_echo = 0; | |
401 | } | |
402 | ||
b0e56780 ACM |
403 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
404 | len = 6 + elapsed_time_len; | |
405 | ||
2d0817d1 ACM |
406 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
407 | return -1; | |
7c657876 ACM |
408 | |
409 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
410 | ||
411 | to = skb_push(skb, len); | |
412 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
413 | *to++ = len; | |
414 | ||
7c657876 ACM |
415 | memcpy(to, &tstamp_echo, 4); |
416 | to += 4; | |
afe00251 | 417 | |
1bc09869 | 418 | if (elapsed_time_len == 2) { |
60fe62e7 | 419 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
420 | memcpy(to, &var16, 2); |
421 | } else if (elapsed_time_len == 4) { | |
60fe62e7 | 422 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
423 | memcpy(to, &var32, 4); |
424 | } | |
7c657876 | 425 | |
2d0817d1 | 426 | return 0; |
7c657876 ACM |
427 | } |
428 | ||
4829007c GR |
429 | static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) |
430 | { | |
431 | struct dccp_sock *dp = dccp_sk(sk); | |
432 | struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec; | |
d7dc7e5f | 433 | const u16 buflen = dccp_ackvec_buflen(av); |
4829007c | 434 | /* Figure out how many options do we need to represent the ackvec */ |
d7dc7e5f GR |
435 | const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN); |
436 | u16 len = buflen + 2 * nr_opts; | |
4829007c GR |
437 | u8 i, nonce = 0; |
438 | const unsigned char *tail, *from; | |
439 | unsigned char *to; | |
440 | ||
441 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
442 | return -1; | |
443 | ||
444 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
445 | ||
446 | to = skb_push(skb, len); | |
d7dc7e5f | 447 | len = buflen; |
4829007c GR |
448 | from = av->av_buf + av->av_buf_head; |
449 | tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN; | |
450 | ||
451 | for (i = 0; i < nr_opts; ++i) { | |
452 | int copylen = len; | |
453 | ||
454 | if (len > DCCP_SINGLE_OPT_MAXLEN) | |
455 | copylen = DCCP_SINGLE_OPT_MAXLEN; | |
456 | ||
457 | /* | |
458 | * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via | |
459 | * its type; ack_nonce is the sum of all individual buf_nonce's. | |
460 | */ | |
461 | nonce ^= av->av_buf_nonce[i]; | |
462 | ||
463 | *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i]; | |
464 | *to++ = copylen + 2; | |
465 | ||
466 | /* Check if buf_head wraps */ | |
467 | if (from + copylen > tail) { | |
468 | const u16 tailsize = tail - from; | |
469 | ||
470 | memcpy(to, from, tailsize); | |
471 | to += tailsize; | |
472 | len -= tailsize; | |
473 | copylen -= tailsize; | |
474 | from = av->av_buf; | |
475 | } | |
476 | ||
477 | memcpy(to, from, copylen); | |
478 | from += copylen; | |
479 | to += copylen; | |
480 | len -= copylen; | |
481 | } | |
482 | /* | |
483 | * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340. | |
484 | */ | |
485 | if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce)) | |
486 | return -ENOBUFS; | |
487 | return 0; | |
488 | } | |
489 | ||
d0440ee6 GR |
490 | /** |
491 | * dccp_insert_option_mandatory - Mandatory option (5.8.2) | |
492 | * Note that since we are using skb_push, this function needs to be called | |
493 | * _after_ inserting the option it is supposed to influence (stack order). | |
494 | */ | |
495 | int dccp_insert_option_mandatory(struct sk_buff *skb) | |
496 | { | |
497 | if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) | |
498 | return -1; | |
499 | ||
500 | DCCP_SKB_CB(skb)->dccpd_opt_len++; | |
501 | *skb_push(skb, 1) = DCCPO_MANDATORY; | |
502 | return 0; | |
503 | } | |
504 | ||
cf9ddf73 GR |
505 | /** |
506 | * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb | |
507 | * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R | |
508 | * @feat: one out of %dccp_feature_numbers | |
509 | * @val: NN value or SP array (preferred element first) to copy | |
510 | * @len: true length of @val in bytes (excluding first element repetition) | |
511 | * @repeat_first: whether to copy the first element of @val twice | |
512 | * The last argument is used to construct Confirm options, where the preferred | |
513 | * value and the preference list appear separately (RFC 4340, 6.3.1). Preference | |
514 | * lists are kept such that the preferred entry is always first, so we only need | |
515 | * to copy twice, and avoid the overhead of cloning into a bigger array. | |
516 | */ | |
517 | int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, | |
518 | u8 *val, u8 len, bool repeat_first) | |
afe00251 | 519 | { |
cf9ddf73 | 520 | u8 tot_len, *to; |
afe00251 | 521 | |
cf9ddf73 GR |
522 | /* take the `Feature' field and possible repetition into account */ |
523 | if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { | |
524 | DCCP_WARN("length %u for feature %u too large\n", len, feat); | |
afe00251 AB |
525 | return -1; |
526 | } | |
527 | ||
cf9ddf73 GR |
528 | if (unlikely(val == NULL || len == 0)) |
529 | len = repeat_first = 0; | |
530 | tot_len = 3 + repeat_first + len; | |
531 | ||
532 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { | |
533 | DCCP_WARN("packet too small for feature %d option!\n", feat); | |
534 | return -1; | |
535 | } | |
536 | DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; | |
afe00251 | 537 | |
cf9ddf73 | 538 | to = skb_push(skb, tot_len); |
afe00251 | 539 | *to++ = type; |
cf9ddf73 | 540 | *to++ = tot_len; |
afe00251 AB |
541 | *to++ = feat; |
542 | ||
cf9ddf73 GR |
543 | if (repeat_first) |
544 | *to++ = *val; | |
afe00251 AB |
545 | if (len) |
546 | memcpy(to, val, len); | |
afe00251 AB |
547 | return 0; |
548 | } | |
549 | ||
af3b867e GR |
550 | /* The length of all options needs to be a multiple of 4 (5.8) */ |
551 | static void dccp_insert_option_padding(struct sk_buff *skb) | |
552 | { | |
553 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
554 | ||
555 | if (padding != 0) { | |
556 | padding = 4 - padding; | |
557 | memset(skb_push(skb, padding), 0, padding); | |
558 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
559 | } | |
560 | } | |
561 | ||
2d0817d1 | 562 | int dccp_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
563 | { |
564 | struct dccp_sock *dp = dccp_sk(sk); | |
565 | ||
566 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
567 | ||
68e074bf | 568 | if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) |
2d0817d1 | 569 | return -1; |
7c657876 | 570 | |
f8a644c0 GR |
571 | if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { |
572 | ||
573 | /* Feature Negotiation */ | |
574 | if (dccp_feat_insert_opts(dp, NULL, skb)) | |
2d0817d1 | 575 | return -1; |
f8a644c0 GR |
576 | |
577 | if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { | |
578 | /* | |
579 | * Obtain RTT sample from Request/Response exchange. | |
580 | * This is currently used in CCID 3 initialisation. | |
581 | */ | |
582 | if (dccp_insert_option_timestamp(sk, skb)) | |
583 | return -1; | |
584 | ||
d7dc7e5f | 585 | } else if (dccp_ackvec_pending(sk) && |
f8a644c0 GR |
586 | dccp_insert_option_ackvec(sk, skb)) { |
587 | return -1; | |
588 | } | |
7c657876 ACM |
589 | } |
590 | ||
507d37cf | 591 | if (dp->dccps_hc_rx_insert_options) { |
2d0817d1 ACM |
592 | if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
593 | return -1; | |
507d37cf ACM |
594 | dp->dccps_hc_rx_insert_options = 0; |
595 | } | |
7c657876 | 596 | |
b4d4f7c7 GR |
597 | if (dp->dccps_timestamp_echo != 0 && |
598 | dccp_insert_option_timestamp_echo(dp, NULL, skb)) | |
599 | return -1; | |
600 | ||
af3b867e GR |
601 | dccp_insert_option_padding(skb); |
602 | return 0; | |
603 | } | |
7c657876 | 604 | |
af3b867e GR |
605 | int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) |
606 | { | |
607 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
7c657876 | 608 | |
f8a644c0 GR |
609 | if (dccp_feat_insert_opts(NULL, dreq, skb)) |
610 | return -1; | |
611 | ||
af3b867e GR |
612 | if (dreq->dreq_timestamp_echo != 0 && |
613 | dccp_insert_option_timestamp_echo(NULL, dreq, skb)) | |
614 | return -1; | |
2d0817d1 | 615 | |
af3b867e | 616 | dccp_insert_option_padding(skb); |
2d0817d1 | 617 | return 0; |
7c657876 | 618 | } |