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; | |
bdf13d20 | 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; | |
64 | unsigned char *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 | /* |
8b819412 GR |
99 | * CCID-specific options are ignored during connection setup, as |
100 | * negotiation may still be in progress (see RFC 4340, 10.3). | |
65907a43 | 101 | * The same applies to Ack Vectors, as these depend on the CCID. |
8b819412 | 102 | */ |
f10ecaee | 103 | if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC || |
65907a43 | 104 | opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) |
8b819412 GR |
105 | goto ignore_option; |
106 | ||
7c657876 ACM |
107 | switch (opt) { |
108 | case DCCPO_PADDING: | |
109 | break; | |
afe00251 AB |
110 | case DCCPO_MANDATORY: |
111 | if (mandatory) | |
112 | goto out_invalid_option; | |
6df9424a ACM |
113 | if (pkt_type != DCCP_PKT_DATA) |
114 | mandatory = 1; | |
afe00251 | 115 | break; |
7c657876 | 116 | case DCCPO_NDP_COUNT: |
5b5d0e70 | 117 | if (len > 6) |
7c657876 ACM |
118 | goto out_invalid_option; |
119 | ||
120 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
5b5d0e70 GR |
121 | dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), |
122 | (unsigned long long)opt_recv->dccpor_ndp); | |
7c657876 | 123 | break; |
d2150b7b GR |
124 | case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: |
125 | if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ | |
cf86314c | 126 | break; |
5a146b97 GR |
127 | rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, |
128 | *value, value + 1, len - 1); | |
129 | if (rc) | |
130 | goto out_featneg_failed; | |
afe00251 | 131 | break; |
7c657876 | 132 | case DCCPO_ACK_VECTOR_0: |
ae31c339 | 133 | case DCCPO_ACK_VECTOR_1: |
c86ab2b6 | 134 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ |
e5a6de91 | 135 | break; |
b235dc4a | 136 | if (dp->dccps_hc_rx_ackvec != NULL && |
bdf13d20 | 137 | dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) |
ae31c339 | 138 | goto out_invalid_option; |
7c657876 ACM |
139 | break; |
140 | case DCCPO_TIMESTAMP: | |
141 | if (len != 4) | |
142 | goto out_invalid_option; | |
b4d4f7c7 GR |
143 | /* |
144 | * RFC 4340 13.1: "The precise time corresponding to | |
145 | * Timestamp Value zero is not specified". We use | |
146 | * zero to indicate absence of a meaningful timestamp. | |
147 | */ | |
76fd1e87 | 148 | opt_val = get_unaligned((__be32 *)value); |
b4d4f7c7 GR |
149 | if (unlikely(opt_val == 0)) { |
150 | DCCP_WARN("Timestamp with zero value\n"); | |
151 | break; | |
152 | } | |
7c657876 | 153 | |
b4d4f7c7 GR |
154 | if (dreq != NULL) { |
155 | dreq->dreq_timestamp_echo = ntohl(opt_val); | |
156 | dreq->dreq_timestamp_time = dccp_timestamp(); | |
157 | } else { | |
158 | opt_recv->dccpor_timestamp = | |
159 | dp->dccps_timestamp_echo = ntohl(opt_val); | |
160 | dp->dccps_timestamp_time = dccp_timestamp(); | |
161 | } | |
09dbc389 | 162 | dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
b4d4f7c7 | 163 | dccp_role(sk), ntohl(opt_val), |
f6ccf554 | 164 | (unsigned long long) |
7c657876 | 165 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
2975abd2 GR |
166 | /* schedule an Ack in case this sender is quiescent */ |
167 | inet_csk_schedule_ack(sk); | |
7c657876 ACM |
168 | break; |
169 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 170 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
171 | goto out_invalid_option; |
172 | ||
76fd1e87 GR |
173 | opt_val = get_unaligned((__be32 *)value); |
174 | opt_recv->dccpor_timestamp_echo = ntohl(opt_val); | |
7c657876 | 175 | |
09dbc389 | 176 | dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
f73f7097 | 177 | "ackno=%llu", dccp_role(sk), |
7690af3f | 178 | opt_recv->dccpor_timestamp_echo, |
f6ccf554 DM |
179 | len + 2, |
180 | (unsigned long long) | |
1bc09869 IM |
181 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
182 | ||
76fd1e87 | 183 | value += 4; |
1bc09869 | 184 | |
76fd1e87 | 185 | if (len == 4) { /* no elapsed time included */ |
f73f7097 | 186 | dccp_pr_debug_cat("\n"); |
1c14ac0a | 187 | break; |
f73f7097 | 188 | } |
1c14ac0a | 189 | |
76fd1e87 GR |
190 | if (len == 6) { /* 2-byte elapsed time */ |
191 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
192 | elapsed_time = ntohs(opt_val2); | |
193 | } else { /* 4-byte elapsed time */ | |
194 | opt_val = get_unaligned((__be32 *)value); | |
195 | elapsed_time = ntohl(opt_val); | |
196 | } | |
1c14ac0a | 197 | |
dcad856f | 198 | dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); |
f73f7097 | 199 | |
1c14ac0a ACM |
200 | /* Give precedence to the biggest ELAPSED_TIME */ |
201 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
202 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
203 | break; |
204 | case DCCPO_ELAPSED_TIME: | |
c86ab2b6 GR |
205 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ |
206 | break; | |
1bc09869 | 207 | |
76fd1e87 GR |
208 | if (len == 2) { |
209 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
210 | elapsed_time = ntohs(opt_val2); | |
c86ab2b6 | 211 | } else if (len == 4) { |
76fd1e87 GR |
212 | opt_val = get_unaligned((__be32 *)value); |
213 | elapsed_time = ntohl(opt_val); | |
c86ab2b6 GR |
214 | } else { |
215 | goto out_invalid_option; | |
76fd1e87 | 216 | } |
1c14ac0a ACM |
217 | |
218 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
219 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 220 | |
09dbc389 GR |
221 | dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
222 | dccp_role(sk), elapsed_time); | |
7c657876 | 223 | break; |
f10ecaee | 224 | case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC: |
7690af3f | 225 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
3306c781 | 226 | pkt_type, opt, value, len)) |
7c657876 | 227 | goto out_invalid_option; |
7c657876 | 228 | break; |
f10ecaee | 229 | case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC: |
7690af3f | 230 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
3306c781 | 231 | pkt_type, opt, value, len)) |
7c657876 | 232 | goto out_invalid_option; |
7c657876 ACM |
233 | break; |
234 | default: | |
59348b19 GR |
235 | DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
236 | "implemented, ignoring", sk, opt, len); | |
7c657876 | 237 | break; |
c9eaf173 | 238 | } |
8b819412 | 239 | ignore_option: |
afe00251 AB |
240 | if (opt != DCCPO_MANDATORY) |
241 | mandatory = 0; | |
7c657876 ACM |
242 | } |
243 | ||
6df9424a ACM |
244 | /* mandatory was the last byte in option list -> reset connection */ |
245 | if (mandatory) | |
246 | goto out_invalid_option; | |
247 | ||
faf61c33 GR |
248 | out_nonsensical_length: |
249 | /* RFC 4340, 5.8: ignore option and all remaining option space */ | |
7c657876 ACM |
250 | return 0; |
251 | ||
252 | out_invalid_option: | |
253 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
5a146b97 GR |
254 | rc = DCCP_RESET_CODE_OPTION_ERROR; |
255 | out_featneg_failed: | |
256 | DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); | |
257 | DCCP_SKB_CB(skb)->dccpd_reset_code = rc; | |
eac7726b GR |
258 | DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; |
259 | DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; | |
260 | DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; | |
7c657876 ACM |
261 | return -1; |
262 | } | |
263 | ||
b61fafc4 ACM |
264 | EXPORT_SYMBOL_GPL(dccp_parse_options); |
265 | ||
b9aaac1c | 266 | void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) |
7c657876 | 267 | { |
b9aaac1c GR |
268 | if (len >= DCCP_OPTVAL_MAXLEN) |
269 | *to++ = (value & 0xFF0000000000ull) >> 40; | |
270 | if (len > 4) | |
271 | *to++ = (value & 0xFF00000000ull) >> 32; | |
7c657876 ACM |
272 | if (len > 3) |
273 | *to++ = (value & 0xFF000000) >> 24; | |
274 | if (len > 2) | |
275 | *to++ = (value & 0xFF0000) >> 16; | |
276 | if (len > 1) | |
277 | *to++ = (value & 0xFF00) >> 8; | |
278 | if (len > 0) | |
279 | *to++ = (value & 0xFF); | |
280 | } | |
281 | ||
5b5d0e70 | 282 | static inline u8 dccp_ndp_len(const u64 ndp) |
7c657876 | 283 | { |
5b5d0e70 GR |
284 | if (likely(ndp <= 0xFF)) |
285 | return 1; | |
286 | return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); | |
7c657876 ACM |
287 | } |
288 | ||
2d0817d1 | 289 | int dccp_insert_option(struct sock *sk, struct sk_buff *skb, |
7c657876 ACM |
290 | const unsigned char option, |
291 | const void *value, const unsigned char len) | |
292 | { | |
293 | unsigned char *to; | |
294 | ||
2d0817d1 ACM |
295 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
296 | return -1; | |
7c657876 ACM |
297 | |
298 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
299 | ||
300 | to = skb_push(skb, len + 2); | |
301 | *to++ = option; | |
302 | *to++ = len + 2; | |
303 | ||
304 | memcpy(to, value, len); | |
2d0817d1 | 305 | return 0; |
7c657876 ACM |
306 | } |
307 | ||
308 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
309 | ||
2d0817d1 | 310 | static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
311 | { |
312 | struct dccp_sock *dp = dccp_sk(sk); | |
5b5d0e70 | 313 | u64 ndp = dp->dccps_ndp_count; |
7c657876 ACM |
314 | |
315 | if (dccp_non_data_packet(skb)) | |
316 | ++dp->dccps_ndp_count; | |
317 | else | |
318 | dp->dccps_ndp_count = 0; | |
319 | ||
320 | if (ndp > 0) { | |
321 | unsigned char *ptr; | |
322 | const int ndp_len = dccp_ndp_len(ndp); | |
323 | const int len = ndp_len + 2; | |
324 | ||
325 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
2d0817d1 | 326 | return -1; |
7c657876 ACM |
327 | |
328 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
329 | ||
330 | ptr = skb_push(skb, len); | |
331 | *ptr++ = DCCPO_NDP_COUNT; | |
332 | *ptr++ = len; | |
333 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
334 | } | |
2d0817d1 ACM |
335 | |
336 | return 0; | |
7c657876 ACM |
337 | } |
338 | ||
339 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
340 | { | |
b1c9fe7b | 341 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
342 | } |
343 | ||
2d0817d1 ACM |
344 | int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb, |
345 | u32 elapsed_time) | |
7c657876 | 346 | { |
7c657876 ACM |
347 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
348 | const int len = 2 + elapsed_time_len; | |
349 | unsigned char *to; | |
350 | ||
1bc09869 | 351 | if (elapsed_time_len == 0) |
2d0817d1 | 352 | return 0; |
7c657876 | 353 | |
2d0817d1 ACM |
354 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
355 | return -1; | |
7c657876 ACM |
356 | |
357 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
358 | ||
359 | to = skb_push(skb, len); | |
360 | *to++ = DCCPO_ELAPSED_TIME; | |
361 | *to++ = len; | |
362 | ||
1bc09869 | 363 | if (elapsed_time_len == 2) { |
60fe62e7 | 364 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
365 | memcpy(to, &var16, 2); |
366 | } else { | |
60fe62e7 | 367 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
368 | memcpy(to, &var32, 4); |
369 | } | |
7c657876 | 370 | |
2d0817d1 | 371 | return 0; |
7c657876 ACM |
372 | } |
373 | ||
d4b81ff7 | 374 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 | 375 | |
2d0817d1 | 376 | int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 377 | { |
4c70f383 | 378 | __be32 now = htonl(dccp_timestamp()); |
1bc09869 IM |
379 | /* yes this will overflow but that is the point as we want a |
380 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
381 | ||
2d0817d1 | 382 | return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
7c657876 ACM |
383 | } |
384 | ||
d4b81ff7 ACM |
385 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
386 | ||
b4d4f7c7 GR |
387 | static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, |
388 | struct dccp_request_sock *dreq, | |
2d0817d1 | 389 | struct sk_buff *skb) |
7c657876 | 390 | { |
60fe62e7 | 391 | __be32 tstamp_echo; |
7c657876 | 392 | unsigned char *to; |
b4d4f7c7 GR |
393 | u32 elapsed_time, elapsed_time_len, len; |
394 | ||
395 | if (dreq != NULL) { | |
396 | elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; | |
397 | tstamp_echo = htonl(dreq->dreq_timestamp_echo); | |
398 | dreq->dreq_timestamp_echo = 0; | |
399 | } else { | |
400 | elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; | |
401 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
402 | dp->dccps_timestamp_echo = 0; | |
403 | } | |
404 | ||
b0e56780 ACM |
405 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
406 | len = 6 + elapsed_time_len; | |
407 | ||
2d0817d1 ACM |
408 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
409 | return -1; | |
7c657876 ACM |
410 | |
411 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
412 | ||
413 | to = skb_push(skb, len); | |
414 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
415 | *to++ = len; | |
416 | ||
7c657876 ACM |
417 | memcpy(to, &tstamp_echo, 4); |
418 | to += 4; | |
afe00251 | 419 | |
1bc09869 | 420 | if (elapsed_time_len == 2) { |
60fe62e7 | 421 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
422 | memcpy(to, &var16, 2); |
423 | } else if (elapsed_time_len == 4) { | |
60fe62e7 | 424 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
425 | memcpy(to, &var32, 4); |
426 | } | |
7c657876 | 427 | |
2d0817d1 | 428 | return 0; |
7c657876 ACM |
429 | } |
430 | ||
d0440ee6 GR |
431 | /** |
432 | * dccp_insert_option_mandatory - Mandatory option (5.8.2) | |
433 | * Note that since we are using skb_push, this function needs to be called | |
434 | * _after_ inserting the option it is supposed to influence (stack order). | |
435 | */ | |
436 | int dccp_insert_option_mandatory(struct sk_buff *skb) | |
437 | { | |
438 | if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) | |
439 | return -1; | |
440 | ||
441 | DCCP_SKB_CB(skb)->dccpd_opt_len++; | |
442 | *skb_push(skb, 1) = DCCPO_MANDATORY; | |
443 | return 0; | |
444 | } | |
445 | ||
cf9ddf73 GR |
446 | /** |
447 | * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb | |
448 | * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R | |
449 | * @feat: one out of %dccp_feature_numbers | |
450 | * @val: NN value or SP array (preferred element first) to copy | |
451 | * @len: true length of @val in bytes (excluding first element repetition) | |
452 | * @repeat_first: whether to copy the first element of @val twice | |
453 | * The last argument is used to construct Confirm options, where the preferred | |
454 | * value and the preference list appear separately (RFC 4340, 6.3.1). Preference | |
455 | * lists are kept such that the preferred entry is always first, so we only need | |
456 | * to copy twice, and avoid the overhead of cloning into a bigger array. | |
457 | */ | |
458 | int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, | |
459 | u8 *val, u8 len, bool repeat_first) | |
afe00251 | 460 | { |
cf9ddf73 | 461 | u8 tot_len, *to; |
afe00251 | 462 | |
cf9ddf73 GR |
463 | /* take the `Feature' field and possible repetition into account */ |
464 | if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { | |
465 | DCCP_WARN("length %u for feature %u too large\n", len, feat); | |
afe00251 AB |
466 | return -1; |
467 | } | |
468 | ||
cf9ddf73 GR |
469 | if (unlikely(val == NULL || len == 0)) |
470 | len = repeat_first = 0; | |
471 | tot_len = 3 + repeat_first + len; | |
472 | ||
473 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { | |
474 | DCCP_WARN("packet too small for feature %d option!\n", feat); | |
475 | return -1; | |
476 | } | |
477 | DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; | |
afe00251 | 478 | |
cf9ddf73 | 479 | to = skb_push(skb, tot_len); |
afe00251 | 480 | *to++ = type; |
cf9ddf73 | 481 | *to++ = tot_len; |
afe00251 AB |
482 | *to++ = feat; |
483 | ||
cf9ddf73 GR |
484 | if (repeat_first) |
485 | *to++ = *val; | |
afe00251 AB |
486 | if (len) |
487 | memcpy(to, val, len); | |
afe00251 AB |
488 | return 0; |
489 | } | |
490 | ||
af3b867e GR |
491 | /* The length of all options needs to be a multiple of 4 (5.8) */ |
492 | static void dccp_insert_option_padding(struct sk_buff *skb) | |
493 | { | |
494 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
495 | ||
496 | if (padding != 0) { | |
497 | padding = 4 - padding; | |
498 | memset(skb_push(skb, padding), 0, padding); | |
499 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
500 | } | |
501 | } | |
502 | ||
2d0817d1 | 503 | int dccp_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
504 | { |
505 | struct dccp_sock *dp = dccp_sk(sk); | |
506 | ||
507 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
508 | ||
68e074bf | 509 | if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb)) |
2d0817d1 | 510 | return -1; |
7c657876 | 511 | |
f8a644c0 GR |
512 | if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { |
513 | ||
514 | /* Feature Negotiation */ | |
515 | if (dccp_feat_insert_opts(dp, NULL, skb)) | |
2d0817d1 | 516 | return -1; |
f8a644c0 GR |
517 | |
518 | if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { | |
519 | /* | |
520 | * Obtain RTT sample from Request/Response exchange. | |
521 | * This is currently used in CCID 3 initialisation. | |
522 | */ | |
523 | if (dccp_insert_option_timestamp(sk, skb)) | |
524 | return -1; | |
525 | ||
b235dc4a | 526 | } else if (dp->dccps_hc_rx_ackvec != NULL && |
f8a644c0 GR |
527 | dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && |
528 | dccp_insert_option_ackvec(sk, skb)) { | |
529 | return -1; | |
530 | } | |
7c657876 ACM |
531 | } |
532 | ||
507d37cf | 533 | if (dp->dccps_hc_rx_insert_options) { |
2d0817d1 ACM |
534 | if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
535 | return -1; | |
507d37cf ACM |
536 | dp->dccps_hc_rx_insert_options = 0; |
537 | } | |
7c657876 | 538 | |
b4d4f7c7 GR |
539 | if (dp->dccps_timestamp_echo != 0 && |
540 | dccp_insert_option_timestamp_echo(dp, NULL, skb)) | |
541 | return -1; | |
542 | ||
af3b867e GR |
543 | dccp_insert_option_padding(skb); |
544 | return 0; | |
545 | } | |
7c657876 | 546 | |
af3b867e GR |
547 | int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) |
548 | { | |
549 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
7c657876 | 550 | |
f8a644c0 GR |
551 | if (dccp_feat_insert_opts(NULL, dreq, skb)) |
552 | return -1; | |
553 | ||
af3b867e GR |
554 | if (dreq->dreq_timestamp_echo != 0 && |
555 | dccp_insert_option_timestamp_echo(NULL, dreq, skb)) | |
556 | return -1; | |
2d0817d1 | 557 | |
af3b867e | 558 | dccp_insert_option_padding(skb); |
2d0817d1 | 559 | return 0; |
7c657876 | 560 | } |