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 | |
02fa460e | 26 | u64 dccp_decode_value_var(const u8 *bf, const u8 len) |
7c657876 | 27 | { |
02fa460e | 28 | u64 value = 0; |
7c657876 | 29 | |
02fa460e 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) |
02fa460e | 35 | value += ((u64)*bf++) << 24; |
7c657876 | 36 | if (len > 2) |
02fa460e | 37 | value += ((u64)*bf++) << 16; |
7c657876 | 38 | if (len > 1) |
02fa460e | 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; | |
410e27a4 | 57 | u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; |
7c657876 ACM |
58 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); |
59 | unsigned char *opt_ptr = options; | |
7690af3f ACM |
60 | const unsigned char *opt_end = (unsigned char *)dh + |
61 | (dh->dccph_doff * 4); | |
7c657876 ACM |
62 | struct dccp_options_received *opt_recv = &dp->dccps_options_received; |
63 | unsigned char opt, len; | |
3ed7cc0f | 64 | unsigned char *uninitialized_var(value); |
1c14ac0a | 65 | u32 elapsed_time; |
76fd1e87 | 66 | __be32 opt_val; |
afe00251 AB |
67 | int rc; |
68 | int mandatory = 0; | |
7c657876 ACM |
69 | |
70 | memset(opt_recv, 0, sizeof(*opt_recv)); | |
71 | ||
fb950496 | 72 | opt = len = 0; |
7c657876 ACM |
73 | while (opt_ptr != opt_end) { |
74 | opt = *opt_ptr++; | |
75 | len = 0; | |
76 | value = NULL; | |
77 | ||
78 | /* Check if this isn't a single byte option */ | |
79 | if (opt > DCCPO_MAX_RESERVED) { | |
80 | if (opt_ptr == opt_end) | |
faf61c33 | 81 | goto out_nonsensical_length; |
7c657876 ACM |
82 | |
83 | len = *opt_ptr++; | |
faf61c33 GR |
84 | if (len < 2) |
85 | goto out_nonsensical_length; | |
7c657876 ACM |
86 | /* |
87 | * Remove the type and len fields, leaving | |
88 | * just the value size | |
89 | */ | |
90 | len -= 2; | |
91 | value = opt_ptr; | |
92 | opt_ptr += len; | |
93 | ||
94 | if (opt_ptr > opt_end) | |
faf61c33 | 95 | goto out_nonsensical_length; |
7c657876 ACM |
96 | } |
97 | ||
8b819412 | 98 | /* |
410e27a4 GR |
99 | * CCID-Specific Options (from RFC 4340, sec. 10.3): |
100 | * | |
101 | * Option numbers 128 through 191 are for options sent from the | |
102 | * HC-Sender to the HC-Receiver; option numbers 192 through 255 | |
103 | * are for options sent from the HC-Receiver to the HC-Sender. | |
104 | * | |
8b819412 GR |
105 | * CCID-specific options are ignored during connection setup, as |
106 | * negotiation may still be in progress (see RFC 4340, 10.3). | |
65907a43 | 107 | * The same applies to Ack Vectors, as these depend on the CCID. |
410e27a4 | 108 | * |
8b819412 | 109 | */ |
410e27a4 | 110 | if (dreq != NULL && (opt >= 128 || |
65907a43 | 111 | opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) |
8b819412 GR |
112 | goto ignore_option; |
113 | ||
7c657876 ACM |
114 | switch (opt) { |
115 | case DCCPO_PADDING: | |
116 | break; | |
afe00251 AB |
117 | case DCCPO_MANDATORY: |
118 | if (mandatory) | |
119 | goto out_invalid_option; | |
6df9424a ACM |
120 | if (pkt_type != DCCP_PKT_DATA) |
121 | mandatory = 1; | |
afe00251 | 122 | break; |
7c657876 | 123 | case DCCPO_NDP_COUNT: |
5b5d0e70 | 124 | if (len > 6) |
7c657876 ACM |
125 | goto out_invalid_option; |
126 | ||
127 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
5b5d0e70 GR |
128 | dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), |
129 | (unsigned long long)opt_recv->dccpor_ndp); | |
7c657876 | 130 | break; |
b1ad0042 GR |
131 | case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: |
132 | if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ | |
cf86314c | 133 | break; |
e77b8363 GR |
134 | rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, |
135 | *value, value + 1, len - 1); | |
136 | if (rc) | |
137 | goto out_featneg_failed; | |
410e27a4 | 138 | break; |
410e27a4 GR |
139 | case DCCPO_ACK_VECTOR_0: |
140 | case DCCPO_ACK_VECTOR_1: | |
141 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ | |
142 | break; | |
6fdd34d4 | 143 | if (dp->dccps_hc_rx_ackvec != NULL && |
410e27a4 GR |
144 | dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) |
145 | goto out_invalid_option; | |
afe00251 | 146 | break; |
7c657876 ACM |
147 | case DCCPO_TIMESTAMP: |
148 | if (len != 4) | |
149 | goto out_invalid_option; | |
b4d4f7c7 GR |
150 | /* |
151 | * RFC 4340 13.1: "The precise time corresponding to | |
152 | * Timestamp Value zero is not specified". We use | |
153 | * zero to indicate absence of a meaningful timestamp. | |
154 | */ | |
76fd1e87 | 155 | opt_val = get_unaligned((__be32 *)value); |
b4d4f7c7 GR |
156 | if (unlikely(opt_val == 0)) { |
157 | DCCP_WARN("Timestamp with zero value\n"); | |
158 | break; | |
159 | } | |
7c657876 | 160 | |
b4d4f7c7 GR |
161 | if (dreq != NULL) { |
162 | dreq->dreq_timestamp_echo = ntohl(opt_val); | |
163 | dreq->dreq_timestamp_time = dccp_timestamp(); | |
164 | } else { | |
165 | opt_recv->dccpor_timestamp = | |
166 | dp->dccps_timestamp_echo = ntohl(opt_val); | |
167 | dp->dccps_timestamp_time = dccp_timestamp(); | |
168 | } | |
09dbc389 | 169 | dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
b4d4f7c7 | 170 | dccp_role(sk), ntohl(opt_val), |
f6ccf554 | 171 | (unsigned long long) |
7c657876 ACM |
172 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
173 | break; | |
174 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 175 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
176 | goto out_invalid_option; |
177 | ||
76fd1e87 GR |
178 | opt_val = get_unaligned((__be32 *)value); |
179 | opt_recv->dccpor_timestamp_echo = ntohl(opt_val); | |
7c657876 | 180 | |
09dbc389 | 181 | dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
f73f7097 | 182 | "ackno=%llu", dccp_role(sk), |
7690af3f | 183 | opt_recv->dccpor_timestamp_echo, |
f6ccf554 DM |
184 | len + 2, |
185 | (unsigned long long) | |
1bc09869 IM |
186 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
187 | ||
76fd1e87 | 188 | value += 4; |
1bc09869 | 189 | |
76fd1e87 | 190 | if (len == 4) { /* no elapsed time included */ |
f73f7097 | 191 | dccp_pr_debug_cat("\n"); |
1c14ac0a | 192 | break; |
f73f7097 | 193 | } |
1c14ac0a | 194 | |
76fd1e87 GR |
195 | if (len == 6) { /* 2-byte elapsed time */ |
196 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
197 | elapsed_time = ntohs(opt_val2); | |
198 | } else { /* 4-byte elapsed time */ | |
199 | opt_val = get_unaligned((__be32 *)value); | |
200 | elapsed_time = ntohl(opt_val); | |
201 | } | |
1c14ac0a | 202 | |
dcad856f | 203 | dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); |
f73f7097 | 204 | |
1c14ac0a ACM |
205 | /* Give precedence to the biggest ELAPSED_TIME */ |
206 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
207 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
208 | break; |
209 | case DCCPO_ELAPSED_TIME: | |
c86ab2b6 GR |
210 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ |
211 | break; | |
1bc09869 | 212 | |
76fd1e87 GR |
213 | if (len == 2) { |
214 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
215 | elapsed_time = ntohs(opt_val2); | |
c86ab2b6 | 216 | } else if (len == 4) { |
76fd1e87 GR |
217 | opt_val = get_unaligned((__be32 *)value); |
218 | elapsed_time = ntohl(opt_val); | |
c86ab2b6 GR |
219 | } else { |
220 | goto out_invalid_option; | |
76fd1e87 | 221 | } |
1c14ac0a ACM |
222 | |
223 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
224 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 225 | |
09dbc389 GR |
226 | dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
227 | dccp_role(sk), elapsed_time); | |
7c657876 | 228 | break; |
4874c131 | 229 | case 128 ... 191: |
7690af3f | 230 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
4874c131 | 231 | pkt_type, opt, value, len)) |
7c657876 | 232 | goto out_invalid_option; |
7c657876 | 233 | break; |
4874c131 | 234 | case 192 ... 255: |
7690af3f | 235 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
4874c131 | 236 | pkt_type, opt, value, len)) |
7c657876 | 237 | goto out_invalid_option; |
7c657876 ACM |
238 | break; |
239 | default: | |
59348b19 GR |
240 | DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
241 | "implemented, ignoring", sk, opt, len); | |
7c657876 | 242 | break; |
c9eaf173 | 243 | } |
8b819412 | 244 | ignore_option: |
afe00251 AB |
245 | if (opt != DCCPO_MANDATORY) |
246 | mandatory = 0; | |
7c657876 ACM |
247 | } |
248 | ||
6df9424a ACM |
249 | /* mandatory was the last byte in option list -> reset connection */ |
250 | if (mandatory) | |
251 | goto out_invalid_option; | |
252 | ||
faf61c33 GR |
253 | out_nonsensical_length: |
254 | /* RFC 4340, 5.8: ignore option and all remaining option space */ | |
7c657876 ACM |
255 | return 0; |
256 | ||
257 | out_invalid_option: | |
258 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
e77b8363 GR |
259 | rc = DCCP_RESET_CODE_OPTION_ERROR; |
260 | out_featneg_failed: | |
261 | DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); | |
262 | DCCP_SKB_CB(skb)->dccpd_reset_code = rc; | |
eac7726b GR |
263 | DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; |
264 | DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; | |
265 | DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; | |
7c657876 ACM |
266 | return -1; |
267 | } | |
268 | ||
b61fafc4 ACM |
269 | EXPORT_SYMBOL_GPL(dccp_parse_options); |
270 | ||
02fa460e | 271 | void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) |
7c657876 | 272 | { |
02fa460e GR |
273 | if (len >= DCCP_OPTVAL_MAXLEN) |
274 | *to++ = (value & 0xFF0000000000ull) >> 40; | |
275 | if (len > 4) | |
276 | *to++ = (value & 0xFF00000000ull) >> 32; | |
7c657876 ACM |
277 | if (len > 3) |
278 | *to++ = (value & 0xFF000000) >> 24; | |
279 | if (len > 2) | |
280 | *to++ = (value & 0xFF0000) >> 16; | |
281 | if (len > 1) | |
282 | *to++ = (value & 0xFF00) >> 8; | |
283 | if (len > 0) | |
284 | *to++ = (value & 0xFF); | |
285 | } | |
286 | ||
5b5d0e70 | 287 | static inline u8 dccp_ndp_len(const u64 ndp) |
7c657876 | 288 | { |
5b5d0e70 GR |
289 | if (likely(ndp <= 0xFF)) |
290 | return 1; | |
4be929be | 291 | return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); |
7c657876 ACM |
292 | } |
293 | ||
a7d13fbf GR |
294 | int dccp_insert_option(struct sk_buff *skb, const unsigned char option, |
295 | const void *value, const unsigned char len) | |
7c657876 ACM |
296 | { |
297 | unsigned char *to; | |
298 | ||
2d0817d1 ACM |
299 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
300 | return -1; | |
7c657876 ACM |
301 | |
302 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
303 | ||
304 | to = skb_push(skb, len + 2); | |
305 | *to++ = option; | |
306 | *to++ = len + 2; | |
307 | ||
308 | memcpy(to, value, len); | |
2d0817d1 | 309 | return 0; |
7c657876 ACM |
310 | } |
311 | ||
312 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
313 | ||
2d0817d1 | 314 | static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
315 | { |
316 | struct dccp_sock *dp = dccp_sk(sk); | |
5b5d0e70 | 317 | u64 ndp = dp->dccps_ndp_count; |
7c657876 ACM |
318 | |
319 | if (dccp_non_data_packet(skb)) | |
320 | ++dp->dccps_ndp_count; | |
321 | else | |
322 | dp->dccps_ndp_count = 0; | |
323 | ||
324 | if (ndp > 0) { | |
325 | unsigned char *ptr; | |
326 | const int ndp_len = dccp_ndp_len(ndp); | |
327 | const int len = ndp_len + 2; | |
328 | ||
329 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
2d0817d1 | 330 | return -1; |
7c657876 ACM |
331 | |
332 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
333 | ||
334 | ptr = skb_push(skb, len); | |
335 | *ptr++ = DCCPO_NDP_COUNT; | |
336 | *ptr++ = len; | |
337 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
338 | } | |
2d0817d1 ACM |
339 | |
340 | return 0; | |
7c657876 ACM |
341 | } |
342 | ||
343 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
344 | { | |
b1c9fe7b | 345 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
346 | } |
347 | ||
a7d13fbf | 348 | int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time) |
7c657876 | 349 | { |
7c657876 ACM |
350 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
351 | const int len = 2 + elapsed_time_len; | |
352 | unsigned char *to; | |
353 | ||
1bc09869 | 354 | if (elapsed_time_len == 0) |
2d0817d1 | 355 | return 0; |
7c657876 | 356 | |
2d0817d1 ACM |
357 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
358 | return -1; | |
7c657876 ACM |
359 | |
360 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
361 | ||
362 | to = skb_push(skb, len); | |
363 | *to++ = DCCPO_ELAPSED_TIME; | |
364 | *to++ = len; | |
365 | ||
1bc09869 | 366 | if (elapsed_time_len == 2) { |
60fe62e7 | 367 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
368 | memcpy(to, &var16, 2); |
369 | } else { | |
60fe62e7 | 370 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
371 | memcpy(to, &var32, 4); |
372 | } | |
7c657876 | 373 | |
2d0817d1 | 374 | return 0; |
7c657876 ACM |
375 | } |
376 | ||
d4b81ff7 | 377 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 | 378 | |
a7d13fbf | 379 | int dccp_insert_option_timestamp(struct sk_buff *skb) |
7c657876 | 380 | { |
4c70f383 | 381 | __be32 now = htonl(dccp_timestamp()); |
1bc09869 IM |
382 | /* yes this will overflow but that is the point as we want a |
383 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
384 | ||
a7d13fbf | 385 | return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
7c657876 ACM |
386 | } |
387 | ||
d4b81ff7 ACM |
388 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
389 | ||
b4d4f7c7 GR |
390 | static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, |
391 | struct dccp_request_sock *dreq, | |
2d0817d1 | 392 | struct sk_buff *skb) |
7c657876 | 393 | { |
60fe62e7 | 394 | __be32 tstamp_echo; |
7c657876 | 395 | unsigned char *to; |
b4d4f7c7 GR |
396 | u32 elapsed_time, elapsed_time_len, len; |
397 | ||
398 | if (dreq != NULL) { | |
399 | elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; | |
400 | tstamp_echo = htonl(dreq->dreq_timestamp_echo); | |
401 | dreq->dreq_timestamp_echo = 0; | |
402 | } else { | |
403 | elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; | |
404 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
405 | dp->dccps_timestamp_echo = 0; | |
406 | } | |
407 | ||
b0e56780 ACM |
408 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
409 | len = 6 + elapsed_time_len; | |
410 | ||
2d0817d1 ACM |
411 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
412 | return -1; | |
7c657876 ACM |
413 | |
414 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
415 | ||
416 | to = skb_push(skb, len); | |
417 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
418 | *to++ = len; | |
419 | ||
7c657876 ACM |
420 | memcpy(to, &tstamp_echo, 4); |
421 | to += 4; | |
afe00251 | 422 | |
1bc09869 | 423 | if (elapsed_time_len == 2) { |
60fe62e7 | 424 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
425 | memcpy(to, &var16, 2); |
426 | } else if (elapsed_time_len == 4) { | |
60fe62e7 | 427 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
428 | memcpy(to, &var32, 4); |
429 | } | |
7c657876 | 430 | |
2d0817d1 | 431 | return 0; |
7c657876 ACM |
432 | } |
433 | ||
d3710566 GR |
434 | /** |
435 | * dccp_insert_option_mandatory - Mandatory option (5.8.2) | |
436 | * Note that since we are using skb_push, this function needs to be called | |
437 | * _after_ inserting the option it is supposed to influence (stack order). | |
438 | */ | |
439 | int dccp_insert_option_mandatory(struct sk_buff *skb) | |
440 | { | |
441 | if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) | |
442 | return -1; | |
443 | ||
444 | DCCP_SKB_CB(skb)->dccpd_opt_len++; | |
445 | *skb_push(skb, 1) = DCCPO_MANDATORY; | |
446 | return 0; | |
447 | } | |
448 | ||
8c862c23 GR |
449 | /** |
450 | * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb | |
451 | * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R | |
452 | * @feat: one out of %dccp_feature_numbers | |
453 | * @val: NN value or SP array (preferred element first) to copy | |
454 | * @len: true length of @val in bytes (excluding first element repetition) | |
455 | * @repeat_first: whether to copy the first element of @val twice | |
456 | * The last argument is used to construct Confirm options, where the preferred | |
457 | * value and the preference list appear separately (RFC 4340, 6.3.1). Preference | |
458 | * lists are kept such that the preferred entry is always first, so we only need | |
459 | * to copy twice, and avoid the overhead of cloning into a bigger array. | |
460 | */ | |
461 | int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, | |
462 | u8 *val, u8 len, bool repeat_first) | |
4829007c | 463 | { |
8c862c23 | 464 | u8 tot_len, *to; |
4829007c | 465 | |
8c862c23 GR |
466 | /* take the `Feature' field and possible repetition into account */ |
467 | if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { | |
468 | DCCP_WARN("length %u for feature %u too large\n", len, feat); | |
4829007c | 469 | return -1; |
c2f42077 | 470 | } |
4829007c | 471 | |
8c862c23 GR |
472 | if (unlikely(val == NULL || len == 0)) |
473 | len = repeat_first = 0; | |
474 | tot_len = 3 + repeat_first + len; | |
475 | ||
476 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { | |
477 | DCCP_WARN("packet too small for feature %d option!\n", feat); | |
478 | return -1; | |
479 | } | |
480 | DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; | |
4829007c | 481 | |
8c862c23 | 482 | to = skb_push(skb, tot_len); |
410e27a4 | 483 | *to++ = type; |
8c862c23 | 484 | *to++ = tot_len; |
410e27a4 | 485 | *to++ = feat; |
4829007c | 486 | |
8c862c23 GR |
487 | if (repeat_first) |
488 | *to++ = *val; | |
410e27a4 GR |
489 | if (len) |
490 | memcpy(to, val, len); | |
d0440ee6 GR |
491 | return 0; |
492 | } | |
493 | ||
af3b867e GR |
494 | /* The length of all options needs to be a multiple of 4 (5.8) */ |
495 | static void dccp_insert_option_padding(struct sk_buff *skb) | |
496 | { | |
497 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
498 | ||
499 | if (padding != 0) { | |
500 | padding = 4 - padding; | |
501 | memset(skb_push(skb, padding), 0, padding); | |
502 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
503 | } | |
504 | } | |
505 | ||
2d0817d1 | 506 | int dccp_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
507 | { |
508 | struct dccp_sock *dp = dccp_sk(sk); | |
509 | ||
510 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
511 | ||
4098dce5 | 512 | if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) |
2d0817d1 | 513 | return -1; |
7c657876 | 514 | |
8b7b6c75 GR |
515 | if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { |
516 | ||
517 | /* Feature Negotiation */ | |
518 | if (dccp_feat_insert_opts(dp, NULL, skb)) | |
2d0817d1 | 519 | return -1; |
8b7b6c75 GR |
520 | |
521 | if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { | |
522 | /* | |
523 | * Obtain RTT sample from Request/Response exchange. | |
59b80802 | 524 | * This is currently used for TFRC initialisation. |
8b7b6c75 | 525 | */ |
a7d13fbf | 526 | if (dccp_insert_option_timestamp(skb)) |
8b7b6c75 GR |
527 | return -1; |
528 | ||
6fdd34d4 | 529 | } else if (dp->dccps_hc_rx_ackvec != NULL && |
8b7b6c75 GR |
530 | dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && |
531 | dccp_insert_option_ackvec(sk, skb)) { | |
532 | return -1; | |
533 | } | |
7c657876 ACM |
534 | } |
535 | ||
507d37cf | 536 | if (dp->dccps_hc_rx_insert_options) { |
2d0817d1 ACM |
537 | if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
538 | return -1; | |
507d37cf ACM |
539 | dp->dccps_hc_rx_insert_options = 0; |
540 | } | |
7c657876 | 541 | |
b4d4f7c7 GR |
542 | if (dp->dccps_timestamp_echo != 0 && |
543 | dccp_insert_option_timestamp_echo(dp, NULL, skb)) | |
544 | return -1; | |
545 | ||
af3b867e GR |
546 | dccp_insert_option_padding(skb); |
547 | return 0; | |
548 | } | |
7c657876 | 549 | |
af3b867e GR |
550 | int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) |
551 | { | |
552 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
7c657876 | 553 | |
8b7b6c75 GR |
554 | if (dccp_feat_insert_opts(NULL, dreq, skb)) |
555 | return -1; | |
556 | ||
59b80802 GR |
557 | /* Obtain RTT sample from Response/Ack exchange (used by TFRC). */ |
558 | if (dccp_insert_option_timestamp(skb)) | |
559 | return -1; | |
560 | ||
af3b867e GR |
561 | if (dreq->dreq_timestamp_echo != 0 && |
562 | dccp_insert_option_timestamp_echo(NULL, dreq, skb)) | |
563 | return -1; | |
2d0817d1 | 564 | |
af3b867e | 565 | dccp_insert_option_padding(skb); |
2d0817d1 | 566 | return 0; |
7c657876 | 567 | } |