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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; | |
3ed7cc0f | 70 | unsigned char *uninitialized_var(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; |
b1ad0042 GR |
137 | case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: |
138 | if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ | |
cf86314c | 139 | break; |
e77b8363 GR |
140 | rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, |
141 | *value, value + 1, len - 1); | |
142 | if (rc) | |
143 | goto out_featneg_failed; | |
410e27a4 | 144 | break; |
410e27a4 GR |
145 | case DCCPO_ACK_VECTOR_0: |
146 | case DCCPO_ACK_VECTOR_1: | |
147 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */ | |
148 | break; | |
149 | ||
150 | if (dccp_msk(sk)->dccpms_send_ack_vector && | |
151 | dccp_ackvec_parse(sk, skb, &ackno, opt, value, len)) | |
152 | goto out_invalid_option; | |
afe00251 | 153 | break; |
7c657876 ACM |
154 | case DCCPO_TIMESTAMP: |
155 | if (len != 4) | |
156 | goto out_invalid_option; | |
b4d4f7c7 GR |
157 | /* |
158 | * RFC 4340 13.1: "The precise time corresponding to | |
159 | * Timestamp Value zero is not specified". We use | |
160 | * zero to indicate absence of a meaningful timestamp. | |
161 | */ | |
76fd1e87 | 162 | opt_val = get_unaligned((__be32 *)value); |
b4d4f7c7 GR |
163 | if (unlikely(opt_val == 0)) { |
164 | DCCP_WARN("Timestamp with zero value\n"); | |
165 | break; | |
166 | } | |
7c657876 | 167 | |
b4d4f7c7 GR |
168 | if (dreq != NULL) { |
169 | dreq->dreq_timestamp_echo = ntohl(opt_val); | |
170 | dreq->dreq_timestamp_time = dccp_timestamp(); | |
171 | } else { | |
172 | opt_recv->dccpor_timestamp = | |
173 | dp->dccps_timestamp_echo = ntohl(opt_val); | |
174 | dp->dccps_timestamp_time = dccp_timestamp(); | |
175 | } | |
09dbc389 | 176 | dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n", |
b4d4f7c7 | 177 | dccp_role(sk), ntohl(opt_val), |
f6ccf554 | 178 | (unsigned long long) |
7c657876 ACM |
179 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
180 | break; | |
181 | case DCCPO_TIMESTAMP_ECHO: | |
1bc09869 | 182 | if (len != 4 && len != 6 && len != 8) |
7c657876 ACM |
183 | goto out_invalid_option; |
184 | ||
76fd1e87 GR |
185 | opt_val = get_unaligned((__be32 *)value); |
186 | opt_recv->dccpor_timestamp_echo = ntohl(opt_val); | |
7c657876 | 187 | |
09dbc389 | 188 | dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, " |
f73f7097 | 189 | "ackno=%llu", dccp_role(sk), |
7690af3f | 190 | opt_recv->dccpor_timestamp_echo, |
f6ccf554 DM |
191 | len + 2, |
192 | (unsigned long long) | |
1bc09869 IM |
193 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
194 | ||
76fd1e87 | 195 | value += 4; |
1bc09869 | 196 | |
76fd1e87 | 197 | if (len == 4) { /* no elapsed time included */ |
f73f7097 | 198 | dccp_pr_debug_cat("\n"); |
1c14ac0a | 199 | break; |
f73f7097 | 200 | } |
1c14ac0a | 201 | |
76fd1e87 GR |
202 | if (len == 6) { /* 2-byte elapsed time */ |
203 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
204 | elapsed_time = ntohs(opt_val2); | |
205 | } else { /* 4-byte elapsed time */ | |
206 | opt_val = get_unaligned((__be32 *)value); | |
207 | elapsed_time = ntohl(opt_val); | |
208 | } | |
1c14ac0a | 209 | |
dcad856f | 210 | dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time); |
f73f7097 | 211 | |
1c14ac0a ACM |
212 | /* Give precedence to the biggest ELAPSED_TIME */ |
213 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
214 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
7c657876 ACM |
215 | break; |
216 | case DCCPO_ELAPSED_TIME: | |
c86ab2b6 GR |
217 | if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */ |
218 | break; | |
1bc09869 | 219 | |
76fd1e87 GR |
220 | if (len == 2) { |
221 | __be16 opt_val2 = get_unaligned((__be16 *)value); | |
222 | elapsed_time = ntohs(opt_val2); | |
c86ab2b6 | 223 | } else if (len == 4) { |
76fd1e87 GR |
224 | opt_val = get_unaligned((__be32 *)value); |
225 | elapsed_time = ntohl(opt_val); | |
c86ab2b6 GR |
226 | } else { |
227 | goto out_invalid_option; | |
76fd1e87 | 228 | } |
1c14ac0a ACM |
229 | |
230 | if (elapsed_time > opt_recv->dccpor_elapsed_time) | |
231 | opt_recv->dccpor_elapsed_time = elapsed_time; | |
1bc09869 | 232 | |
09dbc389 GR |
233 | dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n", |
234 | dccp_role(sk), elapsed_time); | |
7c657876 | 235 | break; |
410e27a4 GR |
236 | case 128 ... 191: { |
237 | const u16 idx = value - options; | |
238 | ||
7690af3f | 239 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
410e27a4 GR |
240 | opt, len, idx, |
241 | value) != 0) | |
7c657876 | 242 | goto out_invalid_option; |
410e27a4 | 243 | } |
7c657876 | 244 | break; |
410e27a4 GR |
245 | case 192 ... 255: { |
246 | const u16 idx = value - options; | |
247 | ||
7690af3f | 248 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
410e27a4 GR |
249 | opt, len, idx, |
250 | value) != 0) | |
7c657876 | 251 | goto out_invalid_option; |
410e27a4 | 252 | } |
7c657876 ACM |
253 | break; |
254 | default: | |
59348b19 GR |
255 | DCCP_CRIT("DCCP(%p): option %d(len=%d) not " |
256 | "implemented, ignoring", sk, opt, len); | |
7c657876 | 257 | break; |
c9eaf173 | 258 | } |
8b819412 | 259 | ignore_option: |
afe00251 AB |
260 | if (opt != DCCPO_MANDATORY) |
261 | mandatory = 0; | |
7c657876 ACM |
262 | } |
263 | ||
6df9424a ACM |
264 | /* mandatory was the last byte in option list -> reset connection */ |
265 | if (mandatory) | |
266 | goto out_invalid_option; | |
267 | ||
faf61c33 GR |
268 | out_nonsensical_length: |
269 | /* RFC 4340, 5.8: ignore option and all remaining option space */ | |
7c657876 ACM |
270 | return 0; |
271 | ||
272 | out_invalid_option: | |
273 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
e77b8363 GR |
274 | rc = DCCP_RESET_CODE_OPTION_ERROR; |
275 | out_featneg_failed: | |
276 | DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc); | |
277 | DCCP_SKB_CB(skb)->dccpd_reset_code = rc; | |
eac7726b GR |
278 | DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt; |
279 | DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0; | |
280 | DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0; | |
7c657876 ACM |
281 | return -1; |
282 | } | |
283 | ||
b61fafc4 ACM |
284 | EXPORT_SYMBOL_GPL(dccp_parse_options); |
285 | ||
02fa460e | 286 | void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) |
7c657876 | 287 | { |
02fa460e GR |
288 | if (len >= DCCP_OPTVAL_MAXLEN) |
289 | *to++ = (value & 0xFF0000000000ull) >> 40; | |
290 | if (len > 4) | |
291 | *to++ = (value & 0xFF00000000ull) >> 32; | |
7c657876 ACM |
292 | if (len > 3) |
293 | *to++ = (value & 0xFF000000) >> 24; | |
294 | if (len > 2) | |
295 | *to++ = (value & 0xFF0000) >> 16; | |
296 | if (len > 1) | |
297 | *to++ = (value & 0xFF00) >> 8; | |
298 | if (len > 0) | |
299 | *to++ = (value & 0xFF); | |
300 | } | |
301 | ||
5b5d0e70 | 302 | static inline u8 dccp_ndp_len(const u64 ndp) |
7c657876 | 303 | { |
5b5d0e70 GR |
304 | if (likely(ndp <= 0xFF)) |
305 | return 1; | |
306 | return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6); | |
7c657876 ACM |
307 | } |
308 | ||
2d0817d1 | 309 | int dccp_insert_option(struct sock *sk, struct sk_buff *skb, |
7c657876 ACM |
310 | const unsigned char option, |
311 | const void *value, const unsigned char len) | |
312 | { | |
313 | unsigned char *to; | |
314 | ||
2d0817d1 ACM |
315 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) |
316 | return -1; | |
7c657876 ACM |
317 | |
318 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
319 | ||
320 | to = skb_push(skb, len + 2); | |
321 | *to++ = option; | |
322 | *to++ = len + 2; | |
323 | ||
324 | memcpy(to, value, len); | |
2d0817d1 | 325 | return 0; |
7c657876 ACM |
326 | } |
327 | ||
328 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
329 | ||
2d0817d1 | 330 | static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
331 | { |
332 | struct dccp_sock *dp = dccp_sk(sk); | |
5b5d0e70 | 333 | u64 ndp = dp->dccps_ndp_count; |
7c657876 ACM |
334 | |
335 | if (dccp_non_data_packet(skb)) | |
336 | ++dp->dccps_ndp_count; | |
337 | else | |
338 | dp->dccps_ndp_count = 0; | |
339 | ||
340 | if (ndp > 0) { | |
341 | unsigned char *ptr; | |
342 | const int ndp_len = dccp_ndp_len(ndp); | |
343 | const int len = ndp_len + 2; | |
344 | ||
345 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
2d0817d1 | 346 | return -1; |
7c657876 ACM |
347 | |
348 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
349 | ||
350 | ptr = skb_push(skb, len); | |
351 | *ptr++ = DCCPO_NDP_COUNT; | |
352 | *ptr++ = len; | |
353 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
354 | } | |
2d0817d1 ACM |
355 | |
356 | return 0; | |
7c657876 ACM |
357 | } |
358 | ||
359 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
360 | { | |
b1c9fe7b | 361 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
362 | } |
363 | ||
2d0817d1 ACM |
364 | int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb, |
365 | u32 elapsed_time) | |
7c657876 | 366 | { |
7c657876 ACM |
367 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
368 | const int len = 2 + elapsed_time_len; | |
369 | unsigned char *to; | |
370 | ||
1bc09869 | 371 | if (elapsed_time_len == 0) |
2d0817d1 | 372 | return 0; |
7c657876 | 373 | |
2d0817d1 ACM |
374 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
375 | return -1; | |
7c657876 ACM |
376 | |
377 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
378 | ||
379 | to = skb_push(skb, len); | |
380 | *to++ = DCCPO_ELAPSED_TIME; | |
381 | *to++ = len; | |
382 | ||
1bc09869 | 383 | if (elapsed_time_len == 2) { |
60fe62e7 | 384 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
385 | memcpy(to, &var16, 2); |
386 | } else { | |
60fe62e7 | 387 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
388 | memcpy(to, &var32, 4); |
389 | } | |
7c657876 | 390 | |
2d0817d1 | 391 | return 0; |
7c657876 ACM |
392 | } |
393 | ||
d4b81ff7 | 394 | EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time); |
7c657876 | 395 | |
2d0817d1 | 396 | int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb) |
7c657876 | 397 | { |
4c70f383 | 398 | __be32 now = htonl(dccp_timestamp()); |
1bc09869 IM |
399 | /* yes this will overflow but that is the point as we want a |
400 | * 10 usec 32 bit timer which mean it wraps every 11.9 hours */ | |
401 | ||
2d0817d1 | 402 | return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); |
7c657876 ACM |
403 | } |
404 | ||
d4b81ff7 ACM |
405 | EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp); |
406 | ||
b4d4f7c7 GR |
407 | static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp, |
408 | struct dccp_request_sock *dreq, | |
2d0817d1 | 409 | struct sk_buff *skb) |
7c657876 | 410 | { |
60fe62e7 | 411 | __be32 tstamp_echo; |
7c657876 | 412 | unsigned char *to; |
b4d4f7c7 GR |
413 | u32 elapsed_time, elapsed_time_len, len; |
414 | ||
415 | if (dreq != NULL) { | |
416 | elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time; | |
417 | tstamp_echo = htonl(dreq->dreq_timestamp_echo); | |
418 | dreq->dreq_timestamp_echo = 0; | |
419 | } else { | |
420 | elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time; | |
421 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
422 | dp->dccps_timestamp_echo = 0; | |
423 | } | |
424 | ||
b0e56780 ACM |
425 | elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
426 | len = 6 + elapsed_time_len; | |
427 | ||
2d0817d1 ACM |
428 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) |
429 | return -1; | |
7c657876 ACM |
430 | |
431 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
432 | ||
433 | to = skb_push(skb, len); | |
434 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
435 | *to++ = len; | |
436 | ||
7c657876 ACM |
437 | memcpy(to, &tstamp_echo, 4); |
438 | to += 4; | |
afe00251 | 439 | |
1bc09869 | 440 | if (elapsed_time_len == 2) { |
60fe62e7 | 441 | const __be16 var16 = htons((u16)elapsed_time); |
1bc09869 IM |
442 | memcpy(to, &var16, 2); |
443 | } else if (elapsed_time_len == 4) { | |
60fe62e7 | 444 | const __be32 var32 = htonl(elapsed_time); |
1bc09869 IM |
445 | memcpy(to, &var32, 4); |
446 | } | |
7c657876 | 447 | |
2d0817d1 | 448 | return 0; |
7c657876 ACM |
449 | } |
450 | ||
d3710566 GR |
451 | /** |
452 | * dccp_insert_option_mandatory - Mandatory option (5.8.2) | |
453 | * Note that since we are using skb_push, this function needs to be called | |
454 | * _after_ inserting the option it is supposed to influence (stack order). | |
455 | */ | |
456 | int dccp_insert_option_mandatory(struct sk_buff *skb) | |
457 | { | |
458 | if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN) | |
459 | return -1; | |
460 | ||
461 | DCCP_SKB_CB(skb)->dccpd_opt_len++; | |
462 | *skb_push(skb, 1) = DCCPO_MANDATORY; | |
463 | return 0; | |
464 | } | |
465 | ||
8c862c23 GR |
466 | /** |
467 | * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb | |
468 | * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R | |
469 | * @feat: one out of %dccp_feature_numbers | |
470 | * @val: NN value or SP array (preferred element first) to copy | |
471 | * @len: true length of @val in bytes (excluding first element repetition) | |
472 | * @repeat_first: whether to copy the first element of @val twice | |
473 | * The last argument is used to construct Confirm options, where the preferred | |
474 | * value and the preference list appear separately (RFC 4340, 6.3.1). Preference | |
475 | * lists are kept such that the preferred entry is always first, so we only need | |
476 | * to copy twice, and avoid the overhead of cloning into a bigger array. | |
477 | */ | |
478 | int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat, | |
479 | u8 *val, u8 len, bool repeat_first) | |
4829007c | 480 | { |
8c862c23 | 481 | u8 tot_len, *to; |
4829007c | 482 | |
8c862c23 GR |
483 | /* take the `Feature' field and possible repetition into account */ |
484 | if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) { | |
485 | DCCP_WARN("length %u for feature %u too large\n", len, feat); | |
4829007c | 486 | return -1; |
c2f42077 | 487 | } |
4829007c | 488 | |
8c862c23 GR |
489 | if (unlikely(val == NULL || len == 0)) |
490 | len = repeat_first = 0; | |
491 | tot_len = 3 + repeat_first + len; | |
492 | ||
493 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) { | |
494 | DCCP_WARN("packet too small for feature %d option!\n", feat); | |
495 | return -1; | |
496 | } | |
497 | DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len; | |
4829007c | 498 | |
8c862c23 | 499 | to = skb_push(skb, tot_len); |
410e27a4 | 500 | *to++ = type; |
8c862c23 | 501 | *to++ = tot_len; |
410e27a4 | 502 | *to++ = feat; |
4829007c | 503 | |
8c862c23 GR |
504 | if (repeat_first) |
505 | *to++ = *val; | |
410e27a4 GR |
506 | if (len) |
507 | memcpy(to, val, len); | |
d0440ee6 | 508 | |
410e27a4 GR |
509 | dccp_pr_debug("%s(%s (%d), ...), length %d\n", |
510 | dccp_feat_typename(type), | |
511 | dccp_feat_name(feat), feat, len); | |
d0440ee6 GR |
512 | return 0; |
513 | } | |
514 | ||
af3b867e GR |
515 | /* The length of all options needs to be a multiple of 4 (5.8) */ |
516 | static void dccp_insert_option_padding(struct sk_buff *skb) | |
517 | { | |
518 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
519 | ||
520 | if (padding != 0) { | |
521 | padding = 4 - padding; | |
522 | memset(skb_push(skb, padding), 0, padding); | |
523 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
524 | } | |
525 | } | |
526 | ||
2d0817d1 | 527 | int dccp_insert_options(struct sock *sk, struct sk_buff *skb) |
7c657876 ACM |
528 | { |
529 | struct dccp_sock *dp = dccp_sk(sk); | |
410e27a4 | 530 | struct dccp_minisock *dmsk = dccp_msk(sk); |
7c657876 ACM |
531 | |
532 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
533 | ||
410e27a4 GR |
534 | if (dmsk->dccpms_send_ndp_count && |
535 | dccp_insert_option_ndp(sk, skb)) | |
2d0817d1 | 536 | return -1; |
7c657876 | 537 | |
8b7b6c75 GR |
538 | if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) { |
539 | ||
540 | /* Feature Negotiation */ | |
541 | if (dccp_feat_insert_opts(dp, NULL, skb)) | |
2d0817d1 | 542 | return -1; |
8b7b6c75 GR |
543 | |
544 | if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) { | |
545 | /* | |
546 | * Obtain RTT sample from Request/Response exchange. | |
547 | * This is currently used in CCID 3 initialisation. | |
548 | */ | |
549 | if (dccp_insert_option_timestamp(sk, skb)) | |
550 | return -1; | |
551 | ||
552 | } else if (dmsk->dccpms_send_ack_vector && | |
553 | dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) && | |
554 | dccp_insert_option_ackvec(sk, skb)) { | |
555 | return -1; | |
556 | } | |
7c657876 ACM |
557 | } |
558 | ||
507d37cf | 559 | if (dp->dccps_hc_rx_insert_options) { |
2d0817d1 ACM |
560 | if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb)) |
561 | return -1; | |
507d37cf ACM |
562 | dp->dccps_hc_rx_insert_options = 0; |
563 | } | |
7c657876 | 564 | |
b4d4f7c7 GR |
565 | if (dp->dccps_timestamp_echo != 0 && |
566 | dccp_insert_option_timestamp_echo(dp, NULL, skb)) | |
567 | return -1; | |
568 | ||
af3b867e GR |
569 | dccp_insert_option_padding(skb); |
570 | return 0; | |
571 | } | |
7c657876 | 572 | |
af3b867e GR |
573 | int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb) |
574 | { | |
575 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
7c657876 | 576 | |
8b7b6c75 GR |
577 | if (dccp_feat_insert_opts(NULL, dreq, skb)) |
578 | return -1; | |
579 | ||
af3b867e GR |
580 | if (dreq->dreq_timestamp_echo != 0 && |
581 | dccp_insert_option_timestamp_echo(NULL, dreq, skb)) | |
582 | return -1; | |
2d0817d1 | 583 | |
af3b867e | 584 | dccp_insert_option_padding(skb); |
2d0817d1 | 585 | return 0; |
7c657876 | 586 | } |