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Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/options.c | |
3 | * | |
4 | * An implementation of the DCCP protocol | |
1bc09869 IM |
5 | * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> |
6 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> | |
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 | |
410e27a4 GR |
26 | int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW; |
27 | int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID; | |
28 | int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID; | |
410e27a4 GR |
29 | int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR; |
30 | int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT; | |
31 | ||
02fa460e | 32 | u64 dccp_decode_value_var(const u8 *bf, const u8 len) |
7c657876 | 33 | { |
02fa460e | 34 | u64 value = 0; |
7c657876 | 35 | |
02fa460e GR |
36 | if (len >= DCCP_OPTVAL_MAXLEN) |
37 | value += ((u64)*bf++) << 40; | |
38 | if (len > 4) | |
39 | value += ((u64)*bf++) << 32; | |
7c657876 | 40 | if (len > 3) |
02fa460e | 41 | value += ((u64)*bf++) << 24; |
7c657876 | 42 | if (len > 2) |
02fa460e | 43 | value += ((u64)*bf++) << 16; |
7c657876 | 44 | if (len > 1) |
02fa460e | 45 | value += ((u64)*bf++) << 8; |
7c657876 ACM |
46 | if (len > 0) |
47 | value += *bf; | |
48 | ||
49 | return value; | |
50 | } | |
51 | ||
8b819412 GR |
52 | /** |
53 | * dccp_parse_options - Parse DCCP options present in @skb | |
54 | * @sk: client|server|listening dccp socket (when @dreq != NULL) | |
55 | * @dreq: request socket to use during connection setup, or NULL | |
56 | */ | |
57 | int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, | |
58 | struct sk_buff *skb) | |
7c657876 ACM |
59 | { |
60 | struct dccp_sock *dp = dccp_sk(sk); | |
7c657876 ACM |
61 | const struct dccp_hdr *dh = dccp_hdr(skb); |
62 | const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; | |
410e27a4 | 63 | u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; |
7c657876 ACM |
64 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); |
65 | unsigned char *opt_ptr = options; | |
7690af3f ACM |
66 | const unsigned char *opt_end = (unsigned char *)dh + |
67 | (dh->dccph_doff * 4); | |
7c657876 ACM |
68 | struct dccp_options_received *opt_recv = &dp->dccps_options_received; |
69 | unsigned char opt, len; | |
70 | unsigned char *value; | |
1c14ac0a | 71 | u32 elapsed_time; |
76fd1e87 | 72 | __be32 opt_val; |
afe00251 AB |
73 | int rc; |
74 | int mandatory = 0; | |
7c657876 ACM |
75 | |
76 | memset(opt_recv, 0, sizeof(*opt_recv)); | |
77 | ||
fb950496 | 78 | opt = len = 0; |
7c657876 ACM |
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) | |
faf61c33 | 87 | goto out_nonsensical_length; |
7c657876 ACM |
88 | |
89 | len = *opt_ptr++; | |
faf61c33 GR |
90 | if (len < 2) |
91 | goto out_nonsensical_length; | |
7c657876 ACM |
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) | |
faf61c33 | 101 | goto out_nonsensical_length; |
7c657876 ACM |
102 | } |
103 | ||
8b819412 | 104 | /* |
410e27a4 GR |
105 | * CCID-Specific Options (from RFC 4340, sec. 10.3): |
106 | * | |
107 | * Option numbers 128 through 191 are for options sent from the | |
108 | * HC-Sender to the HC-Receiver; option numbers 192 through 255 | |
109 | * are for options sent from the HC-Receiver to the HC-Sender. | |
110 | * | |
8b819412 GR |
111 | * CCID-specific options are ignored during connection setup, as |
112 | * negotiation may still be in progress (see RFC 4340, 10.3). | |
65907a43 | 113 | * The same applies to Ack Vectors, as these depend on the CCID. |
410e27a4 | 114 | * |
8b819412 | 115 | */ |
410e27a4 | 116 | if (dreq != NULL && (opt >= 128 || |
65907a43 | 117 | opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1)) |
8b819412 GR |
118 | goto ignore_option; |
119 | ||
7c657876 ACM |
120 | switch (opt) { |
121 | case DCCPO_PADDING: | |
122 | break; | |
afe00251 AB |
123 | case DCCPO_MANDATORY: |
124 | if (mandatory) | |
125 | goto out_invalid_option; | |
6df9424a ACM |
126 | if (pkt_type != DCCP_PKT_DATA) |
127 | mandatory = 1; | |
afe00251 | 128 | break; |
7c657876 | 129 | case DCCPO_NDP_COUNT: |
5b5d0e70 | 130 | if (len > 6) |
7c657876 ACM |
131 | goto out_invalid_option; |
132 | ||
133 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
5b5d0e70 GR |
134 | dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk), |
135 | (unsigned long long)opt_recv->dccpor_ndp); | |
7c657876 | 136 | break; |
410e27a4 GR |
137 | case DCCPO_CHANGE_L: |
138 | /* fall through */ | |
139 | case DCCPO_CHANGE_R: | |
140 | if (pkt_type == DCCP_PKT_DATA) | |
cf86314c | 141 | break; |
410e27a4 GR |
142 | if (len < 2) |
143 | goto out_invalid_option; | |
144 | rc = dccp_feat_change_recv(sk, opt, *value, value + 1, | |
145 | len - 1); | |
146 | /* | |
147 | * When there is a change error, change_recv is | |
148 | * responsible for dealing with it. i.e. reply with an | |
149 | * empty confirm. | |
150 | * If the change was mandatory, then we need to die. | |
151 | */ | |
152 | if (rc && mandatory) | |
153 | goto out_invalid_option; | |
154 | break; | |
155 | case DCCPO_CONFIRM_L: | |
156 | /* fall through */ | |
157 | case DCCPO_CONFIRM_R: | |
158 | if (pkt_type == DCCP_PKT_DATA) | |
159 | break; | |
160 | if (len < 2) /* FIXME this disallows empty confirm */ | |
161 | goto out_invalid_option; | |
162 | if (dccp_feat_confirm_recv(sk, opt, *value, | |
163 | value + 1, len - 1)) | |
164 | goto out_invalid_option; | |
165 | break; | |
166 | case DCCPO_ACK_VECTOR_0: | |
167 | case DCCPO_ACK_VECTOR_1: | |
168 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ | |
169 | break; | |
170 | ||
171 | if (dccp_msk(sk)->dccpms_send_ack_vector && | |
172 | dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) | |
173 | goto out_invalid_option; | |
afe00251 | 174 | break; |
7c657876 ACM |
175 | case DCCPO_TIMESTAMP: |
176 | if (len != 4) | |
177 | goto out_invalid_option; | |
b4d4f7c7 GR |
178 | /* |
179 | * RFC 4340 13.1: "The precise time corresponding to | |
180 | * Timestamp Value zero is not specified". We use | |
181 | * zero to indicate absence of a meaningful timestamp. | |
182 | */ | |
76fd1e87 | 183 | opt_val = get_unaligned((__be32 *)value); |
b4d4f7c7 GR |
184 | if (unlikely(opt_val == 0)) { |
185 | DCCP_WARN("Timestamp with zero value\n"); | |
186 | break; | |
187 | } | |
7c657876 | 188 | |
b4d4f7c7 GR |
189 | if (dreq != NULL) { |
190 | dreq->dreq_timestamp_echo = ntohl(opt_val); | |
191 | dreq->dreq_timestamp_time = dccp_timestamp(); | |
192 | } else { | |
193 | opt_recv->dccpor_timestamp = | |
194 | dp->dccps_timestamp_echo = ntohl(opt_val); | |
195 | dp->dccps_timestamp_time = dccp_timestamp(); | |
196 | } | |
09dbc389 | 197 | dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
b4d4f7c7 | 198 | dccp_role(sk), ntohl(opt_val), |
f6ccf554 | 199 | (unsigned long long) |
7c657876 ACM |
200 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
201 | break; | |
202 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 203 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
204 | goto out_invalid_option; |
205 | ||
76fd1e87 GR |
206 | opt_val = get_unaligned((__be32 *)value); |
207 | opt_recv->dccpor_timestamp_echo = ntohl(opt_val); | |
7c657876 | 208 | |
09dbc389 | 209 | dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
f73f7097 | 210 | "ackno=%llu", dccp_role(sk), |
7690af3f | 211 | opt_recv->dccpor_timestamp_echo, |
f6ccf554 DM |
212 | len + 2, |
213 | (unsigned long long) | |
1bc09869 IM |
214 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
215 | ||
76fd1e87 | 216 | value += 4; |
1bc09869 | 217 | |
76fd1e87 | 218 | if (len == 4) { /* no elapsed time included */ |
f73f7097 | 219 | dccp_pr_debug_cat("\n"); |
1c14ac0a | 220 | break; |
f73f7097 | 221 | } |
1c14ac0a | 222 | |
76fd1e87 GR |
223 | if (len == 6) { /* 2-byte elapsed time */ |
224 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
225 | elapsed_time = ntohs(opt_val2); | |
226 | } else { /* 4-byte elapsed time */ | |
227 | opt_val = get_unaligned((__be32 *)value); | |
228 | elapsed_time = ntohl(opt_val); | |
229 | } | |
1c14ac0a | 230 | |
dcad856f | 231 | dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); |
f73f7097 | 232 | |
1c14ac0a ACM |
233 | /* Give precedence to the biggest ELAPSED_TIME */ |
234 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
235 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
236 | break; |
237 | case DCCPO_ELAPSED_TIME: | |
c86ab2b6 GR |
238 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ |
239 | break; | |
1bc09869 | 240 | |
76fd1e87 GR |
241 | if (len == 2) { |
242 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
243 | elapsed_time = ntohs(opt_val2); | |
c86ab2b6 | 244 | } else if (len == 4) { |
76fd1e87 GR |
245 | opt_val = get_unaligned((__be32 *)value); |
246 | elapsed_time = ntohl(opt_val); | |
c86ab2b6 GR |
247 | } else { |
248 | goto out_invalid_option; | |
76fd1e87 | 249 | } |
1c14ac0a ACM |
250 | |
251 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
252 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 253 | |
09dbc389 GR |
254 | dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
255 | dccp_role(sk), elapsed_time); | |
7c657876 | 256 | break; |
410e27a4 GR |
257 | case 128 ... 191: { |
258 | const u16 idx = value - options; | |
259 | ||
7690af3f | 260 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
410e27a4 GR |
261 | opt, len, idx, |
262 | value) != 0) | |
7c657876 | 263 | goto out_invalid_option; |
410e27a4 | 264 | } |
7c657876 | 265 | break; |
410e27a4 GR |
266 | case 192 ... 255: { |
267 | const u16 idx = value - options; | |
268 | ||
7690af3f | 269 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
410e27a4 GR |
270 | opt, len, idx, |
271 | value) != 0) | |
7c657876 | 272 | goto out_invalid_option; |
410e27a4 | 273 | } |
7c657876 ACM |
274 | break; |
275 | default: | |
59348b19 GR |
276 | DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
277 | "implemented, ignoring", sk, opt, len); | |
7c657876 | 278 | break; |
c9eaf173 | 279 | } |
8b819412 | 280 | ignore_option: |
afe00251 AB |
281 | if (opt != DCCPO_MANDATORY) |
282 | mandatory = 0; | |
7c657876 ACM |
283 | } |
284 | ||
6df9424a ACM |
285 | /* mandatory was the last byte in option list -> reset connection */ |
286 | if (mandatory) | |
287 | goto out_invalid_option; | |
288 | ||
faf61c33 GR |
289 | out_nonsensical_length: |
290 | /* RFC 4340, 5.8: ignore option and all remaining option space */ | |
7c657876 ACM |
291 | return 0; |
292 | ||
293 | out_invalid_option: | |
294 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
410e27a4 GR |
295 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR; |
296 | DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len); | |
eac7726b GR |
297 | DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; |
298 | DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; | |
299 | DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; | |
7c657876 ACM |
300 | return -1; |
301 | } | |
302 | ||
b61fafc4 ACM |
303 | EXPORT_SYMBOL_GPL(dccp_parse_options); |
304 | ||
02fa460e | 305 | void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) |
7c657876 | 306 | { |
02fa460e GR |
307 | if (len >= DCCP_OPTVAL_MAXLEN) |
308 | *to++ = (value & 0xFF0000000000ull) >> 40; | |
309 | if (len > 4) | |
310 | *to++ = (value & 0xFF00000000ull) >> 32; | |
7c657876 ACM |
311 | if (len > 3) |
312 | *to++ = (value & 0xFF000000) >> 24; | |
313 | if (len > 2) | |
314 | *to++ = (value & 0xFF0000) >> 16; | |
315 | if (len > 1) | |
316 | *to++ = (value & 0xFF00) >> 8; | |
317 | if (len > 0) | |
318 | *to++ = (value & 0xFF); | |
319 | } | |
320 | ||
5b5d0e70 | 321 | static inline u8 dccp_ndp_len(const u64 ndp) |
7c657876 | 322 | { |
5b5d0e70 GR |
323 | if (likely(ndp <= 0xFF)) |
324 | return 1; | |
325 | return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); | |
7c657876 ACM |
326 | } |
327 | ||
2d0817d1 | 328 | int dccp_insert_option(struct sock *sk, struct sk_buff *skb, |
7c657876 ACM |
329 | const unsigned char option, |
330 | const void *value, const unsigned char len) | |
331 | { | |
332 | unsigned char *to; | |
333 | ||
2d0817d1 ACM |
334 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
335 | return -1; | |
7c657876 ACM |
336 | |
337 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
338 | ||
339 | to = skb_push(skb, len + 2); | |
340 | *to++ = option; | |
341 | *to++ = len + 2; | |
342 | ||
343 | memcpy(to, value, len); | |
2d0817d1 | 344 | return 0; |
7c657876 ACM |
345 | } |
346 | ||
347 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
348 | ||
2d0817d1 | 349 | static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
350 | { |
351 | struct dccp_sock *dp = dccp_sk(sk); | |
5b5d0e70 | 352 | u64 ndp = dp->dccps_ndp_count; |
7c657876 ACM |
353 | |
354 | if (dccp_non_data_packet(skb)) | |
355 | ++dp->dccps_ndp_count; | |
356 | else | |
357 | dp->dccps_ndp_count = 0; | |
358 | ||
359 | if (ndp > 0) { | |
360 | unsigned char *ptr; | |
361 | const int ndp_len = dccp_ndp_len(ndp); | |
362 | const int len = ndp_len + 2; | |
363 | ||
364 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
2d0817d1 | 365 | return -1; |
7c657876 ACM |
366 | |
367 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
368 | ||
369 | ptr = skb_push(skb, len); | |
370 | *ptr++ = DCCPO_NDP_COUNT; | |
371 | *ptr++ = len; | |
372 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
373 | } | |
2d0817d1 ACM |
374 | |
375 | return 0; | |
7c657876 ACM |
376 | } |
377 | ||
378 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
379 | { | |
b1c9fe7b | 380 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
381 | } |
382 | ||
2d0817d1 ACM |
383 | int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb, |
384 | u32 elapsed_time) | |
7c657876 | 385 | { |
7c657876 ACM |
386 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
387 | const int len = 2 + elapsed_time_len; | |
388 | unsigned char *to; | |
389 | ||
1bc09869 | 390 | if (elapsed_time_len == 0) |
2d0817d1 | 391 | return 0; |
7c657876 | 392 | |
2d0817d1 ACM |
393 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
394 | return -1; | |
7c657876 ACM |
395 | |
396 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
397 | ||
398 | to = skb_push(skb, len); | |
399 | *to++ = DCCPO_ELAPSED_TIME; | |
400 | *to++ = len; | |
401 | ||
1bc09869 | 402 | if (elapsed_time_len == 2) { |
60fe62e7 | 403 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
404 | memcpy(to, &var16, 2); |
405 | } else { | |
60fe62e7 | 406 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
407 | memcpy(to, &var32, 4); |
408 | } | |
7c657876 | 409 | |
2d0817d1 | 410 | return 0; |
7c657876 ACM |
411 | } |
412 | ||
d4b81ff7 | 413 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 | 414 | |
2d0817d1 | 415 | int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 416 | { |
4c70f383 | 417 | __be32 now = htonl(dccp_timestamp()); |
1bc09869 IM |
418 | /* yes this will overflow but that is the point as we want a |
419 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
420 | ||
2d0817d1 | 421 | return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
7c657876 ACM |
422 | } |
423 | ||
d4b81ff7 ACM |
424 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
425 | ||
b4d4f7c7 GR |
426 | static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, |
427 | struct dccp_request_sock *dreq, | |
2d0817d1 | 428 | struct sk_buff *skb) |
7c657876 | 429 | { |
60fe62e7 | 430 | __be32 tstamp_echo; |
7c657876 | 431 | unsigned char *to; |
b4d4f7c7 GR |
432 | u32 elapsed_time, elapsed_time_len, len; |
433 | ||
434 | if (dreq != NULL) { | |
435 | elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; | |
436 | tstamp_echo = htonl(dreq->dreq_timestamp_echo); | |
437 | dreq->dreq_timestamp_echo = 0; | |
438 | } else { | |
439 | elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; | |
440 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
441 | dp->dccps_timestamp_echo = 0; | |
442 | } | |
443 | ||
b0e56780 ACM |
444 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
445 | len = 6 + elapsed_time_len; | |
446 | ||
2d0817d1 ACM |
447 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
448 | return -1; | |
7c657876 ACM |
449 | |
450 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
451 | ||
452 | to = skb_push(skb, len); | |
453 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
454 | *to++ = len; | |
455 | ||
7c657876 ACM |
456 | memcpy(to, &tstamp_echo, 4); |
457 | to += 4; | |
afe00251 | 458 | |
1bc09869 | 459 | if (elapsed_time_len == 2) { |
60fe62e7 | 460 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
461 | memcpy(to, &var16, 2); |
462 | } else if (elapsed_time_len == 4) { | |
60fe62e7 | 463 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
464 | memcpy(to, &var32, 4); |
465 | } | |
7c657876 | 466 | |
2d0817d1 | 467 | return 0; |
7c657876 ACM |
468 | } |
469 | ||
d3710566 GR |
470 | /** |
471 | * dccp_insert_option_mandatory - Mandatory option (5.8.2) | |
472 | * Note that since we are using skb_push, this function needs to be called | |
473 | * _after_ inserting the option it is supposed to influence (stack order). | |
474 | */ | |
475 | int dccp_insert_option_mandatory(struct sk_buff *skb) | |
476 | { | |
477 | if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) | |
478 | return -1; | |
479 | ||
480 | DCCP_SKB_CB(skb)->dccpd_opt_len++; | |
481 | *skb_push(skb, 1) = DCCPO_MANDATORY; | |
482 | return 0; | |
483 | } | |
484 | ||
8c862c23 GR |
485 | /** |
486 | * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb | |
487 | * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R | |
488 | * @feat: one out of %dccp_feature_numbers | |
489 | * @val: NN value or SP array (preferred element first) to copy | |
490 | * @len: true length of @val in bytes (excluding first element repetition) | |
491 | * @repeat_first: whether to copy the first element of @val twice | |
492 | * The last argument is used to construct Confirm options, where the preferred | |
493 | * value and the preference list appear separately (RFC 4340, 6.3.1). Preference | |
494 | * lists are kept such that the preferred entry is always first, so we only need | |
495 | * to copy twice, and avoid the overhead of cloning into a bigger array. | |
496 | */ | |
497 | int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, | |
498 | u8 *val, u8 len, bool repeat_first) | |
4829007c | 499 | { |
8c862c23 | 500 | u8 tot_len, *to; |
4829007c | 501 | |
8c862c23 GR |
502 | /* take the `Feature' field and possible repetition into account */ |
503 | if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { | |
504 | DCCP_WARN("length %u for feature %u too large\n", len, feat); | |
4829007c | 505 | return -1; |
c2f42077 | 506 | } |
4829007c | 507 | |
8c862c23 GR |
508 | if (unlikely(val == NULL || len == 0)) |
509 | len = repeat_first = 0; | |
510 | tot_len = 3 + repeat_first + len; | |
511 | ||
512 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { | |
513 | DCCP_WARN("packet too small for feature %d option!\n", feat); | |
514 | return -1; | |
515 | } | |
516 | DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; | |
4829007c | 517 | |
8c862c23 | 518 | to = skb_push(skb, tot_len); |
410e27a4 | 519 | *to++ = type; |
8c862c23 | 520 | *to++ = tot_len; |
410e27a4 | 521 | *to++ = feat; |
4829007c | 522 | |
8c862c23 GR |
523 | if (repeat_first) |
524 | *to++ = *val; | |
410e27a4 GR |
525 | if (len) |
526 | memcpy(to, val, len); | |
d0440ee6 | 527 | |
410e27a4 GR |
528 | dccp_pr_debug("%s(%s (%d), ...), length %d\n", |
529 | dccp_feat_typename(type), | |
530 | dccp_feat_name(feat), feat, len); | |
d0440ee6 GR |
531 | return 0; |
532 | } | |
533 | ||
af3b867e GR |
534 | /* The length of all options needs to be a multiple of 4 (5.8) */ |
535 | static void dccp_insert_option_padding(struct sk_buff *skb) | |
536 | { | |
537 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
538 | ||
539 | if (padding != 0) { | |
540 | padding = 4 - padding; | |
541 | memset(skb_push(skb, padding), 0, padding); | |
542 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
543 | } | |
544 | } | |
545 | ||
2d0817d1 | 546 | int dccp_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
547 | { |
548 | struct dccp_sock *dp = dccp_sk(sk); | |
410e27a4 | 549 | struct dccp_minisock *dmsk = dccp_msk(sk); |
7c657876 ACM |
550 | |
551 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
552 | ||
410e27a4 GR |
553 | if (dmsk->dccpms_send_ndp_count && |
554 | dccp_insert_option_ndp(sk, skb)) | |
2d0817d1 | 555 | return -1; |
7c657876 | 556 | |
410e27a4 GR |
557 | if (!dccp_packet_without_ack(skb)) { |
558 | if (dmsk->dccpms_send_ack_vector && | |
559 | dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && | |
560 | dccp_insert_option_ackvec(sk, skb)) | |
2d0817d1 | 561 | return -1; |
7c657876 ACM |
562 | } |
563 | ||
507d37cf | 564 | if (dp->dccps_hc_rx_insert_options) { |
2d0817d1 ACM |
565 | if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
566 | return -1; | |
507d37cf ACM |
567 | dp->dccps_hc_rx_insert_options = 0; |
568 | } | |
7c657876 | 569 | |
410e27a4 GR |
570 | /* |
571 | * Obtain RTT sample from Request/Response exchange. | |
572 | * This is currently used in CCID 3 initialisation. | |
573 | */ | |
574 | if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST && | |
575 | dccp_insert_option_timestamp(sk, skb)) | |
576 | return -1; | |
577 | ||
b4d4f7c7 GR |
578 | if (dp->dccps_timestamp_echo != 0 && |
579 | dccp_insert_option_timestamp_echo(dp, NULL, skb)) | |
580 | return -1; | |
581 | ||
af3b867e GR |
582 | dccp_insert_option_padding(skb); |
583 | return 0; | |
584 | } | |
7c657876 | 585 | |
af3b867e GR |
586 | int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) |
587 | { | |
588 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
7c657876 | 589 | |
af3b867e GR |
590 | if (dreq->dreq_timestamp_echo != 0 && |
591 | dccp_insert_option_timestamp_echo(NULL, dreq, skb)) | |
592 | return -1; | |
2d0817d1 | 593 | |
af3b867e | 594 | dccp_insert_option_padding(skb); |
2d0817d1 | 595 | return 0; |
7c657876 | 596 | } |