Commit | Line | Data |
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7c657876 ACM |
1 | /* |
2 | * net/dccp/options.c | |
3 | * | |
4 | * An implementation of the DCCP protocol | |
5 | * Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> | |
6 | * Arnaldo Carvalho de Melo <acme@ghostprotocols.net> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | */ | |
13 | #include <linux/config.h> | |
14 | #include <linux/dccp.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/types.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/skbuff.h> | |
19 | ||
20 | #include "ccid.h" | |
21 | #include "dccp.h" | |
22 | ||
23 | static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap, | |
24 | struct sock *sk, | |
25 | const u64 ackno, | |
26 | const unsigned char len, | |
27 | const unsigned char *vector); | |
28 | ||
29 | /* stores the default values for new connection. may be changed with sysctl */ | |
30 | static const struct dccp_options dccpo_default_values = { | |
31 | .dccpo_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW, | |
32 | .dccpo_ccid = DCCPF_INITIAL_CCID, | |
33 | .dccpo_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR, | |
34 | .dccpo_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT, | |
35 | }; | |
36 | ||
37 | void dccp_options_init(struct dccp_options *dccpo) | |
38 | { | |
39 | memcpy(dccpo, &dccpo_default_values, sizeof(*dccpo)); | |
40 | } | |
41 | ||
42 | static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) | |
43 | { | |
44 | u32 value = 0; | |
45 | ||
46 | if (len > 3) | |
47 | value += *bf++ << 24; | |
48 | if (len > 2) | |
49 | value += *bf++ << 16; | |
50 | if (len > 1) | |
51 | value += *bf++ << 8; | |
52 | if (len > 0) | |
53 | value += *bf; | |
54 | ||
55 | return value; | |
56 | } | |
57 | ||
58 | int dccp_parse_options(struct sock *sk, struct sk_buff *skb) | |
59 | { | |
60 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 61 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
62 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
63 | "CLIENT rx opt: " : "server rx opt: "; | |
7c657876 ACM |
64 | #endif |
65 | const struct dccp_hdr *dh = dccp_hdr(skb); | |
66 | const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type; | |
67 | unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb); | |
68 | unsigned char *opt_ptr = options; | |
7690af3f ACM |
69 | const unsigned char *opt_end = (unsigned char *)dh + |
70 | (dh->dccph_doff * 4); | |
7c657876 ACM |
71 | struct dccp_options_received *opt_recv = &dp->dccps_options_received; |
72 | unsigned char opt, len; | |
73 | unsigned char *value; | |
74 | ||
75 | memset(opt_recv, 0, sizeof(*opt_recv)); | |
76 | ||
77 | while (opt_ptr != opt_end) { | |
78 | opt = *opt_ptr++; | |
79 | len = 0; | |
80 | value = NULL; | |
81 | ||
82 | /* Check if this isn't a single byte option */ | |
83 | if (opt > DCCPO_MAX_RESERVED) { | |
84 | if (opt_ptr == opt_end) | |
85 | goto out_invalid_option; | |
86 | ||
87 | len = *opt_ptr++; | |
88 | if (len < 3) | |
89 | goto out_invalid_option; | |
90 | /* | |
91 | * Remove the type and len fields, leaving | |
92 | * just the value size | |
93 | */ | |
94 | len -= 2; | |
95 | value = opt_ptr; | |
96 | opt_ptr += len; | |
97 | ||
98 | if (opt_ptr > opt_end) | |
99 | goto out_invalid_option; | |
100 | } | |
101 | ||
102 | switch (opt) { | |
103 | case DCCPO_PADDING: | |
104 | break; | |
105 | case DCCPO_NDP_COUNT: | |
106 | if (len > 3) | |
107 | goto out_invalid_option; | |
108 | ||
109 | opt_recv->dccpor_ndp = dccp_decode_value_var(value, len); | |
7690af3f ACM |
110 | dccp_pr_debug("%sNDP count=%d\n", debug_prefix, |
111 | opt_recv->dccpor_ndp); | |
7c657876 ACM |
112 | break; |
113 | case DCCPO_ACK_VECTOR_0: | |
114 | if (len > DCCP_MAX_ACK_VECTOR_LEN) | |
115 | goto out_invalid_option; | |
116 | ||
117 | if (pkt_type == DCCP_PKT_DATA) | |
118 | continue; | |
119 | ||
120 | opt_recv->dccpor_ack_vector_len = len; | |
121 | opt_recv->dccpor_ack_vector_idx = value - options; | |
122 | ||
123 | dccp_pr_debug("%sACK vector 0, len=%d, ack_ackno=%llu\n", | |
f6ccf554 DM |
124 | debug_prefix, len, |
125 | (unsigned long long) | |
126 | DCCP_SKB_CB(skb)->dccpd_ack_seq); | |
7c657876 ACM |
127 | dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, |
128 | value, len); | |
7690af3f ACM |
129 | dccp_ackpkts_check_rcv_ackvector(dp->dccps_hc_rx_ackpkts, |
130 | sk, | |
131 | DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
7c657876 ACM |
132 | len, value); |
133 | break; | |
134 | case DCCPO_TIMESTAMP: | |
135 | if (len != 4) | |
136 | goto out_invalid_option; | |
137 | ||
138 | opt_recv->dccpor_timestamp = ntohl(*(u32 *)value); | |
139 | ||
140 | dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp; | |
141 | dp->dccps_timestamp_time = jiffies; | |
142 | ||
143 | dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n", | |
144 | debug_prefix, opt_recv->dccpor_timestamp, | |
f6ccf554 | 145 | (unsigned long long) |
7c657876 ACM |
146 | DCCP_SKB_CB(skb)->dccpd_ack_seq); |
147 | break; | |
148 | case DCCPO_TIMESTAMP_ECHO: | |
149 | if (len < 4 || len > 8) | |
150 | goto out_invalid_option; | |
151 | ||
152 | opt_recv->dccpor_timestamp_echo = ntohl(*(u32 *)value); | |
153 | ||
7690af3f ACM |
154 | dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, " |
155 | "diff=%u\n", | |
156 | debug_prefix, | |
157 | opt_recv->dccpor_timestamp_echo, | |
f6ccf554 DM |
158 | len + 2, |
159 | (unsigned long long) | |
160 | DCCP_SKB_CB(skb)->dccpd_ack_seq, | |
7690af3f ACM |
161 | (tcp_time_stamp - |
162 | opt_recv->dccpor_timestamp_echo)); | |
163 | ||
164 | opt_recv->dccpor_elapsed_time = | |
165 | dccp_decode_value_var(value + 4, | |
166 | len - 4); | |
167 | dccp_pr_debug("%sTIMESTAMP_ECHO ELAPSED_TIME=%d\n", | |
168 | debug_prefix, | |
7c657876 ACM |
169 | opt_recv->dccpor_elapsed_time); |
170 | break; | |
171 | case DCCPO_ELAPSED_TIME: | |
172 | if (len > 4) | |
173 | goto out_invalid_option; | |
174 | ||
175 | if (pkt_type == DCCP_PKT_DATA) | |
176 | continue; | |
7690af3f ACM |
177 | opt_recv->dccpor_elapsed_time = |
178 | dccp_decode_value_var(value, len); | |
7c657876 ACM |
179 | dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix, |
180 | opt_recv->dccpor_elapsed_time); | |
181 | break; | |
182 | /* | |
183 | * From draft-ietf-dccp-spec-11.txt: | |
184 | * | |
7690af3f ACM |
185 | * Option numbers 128 through 191 are for |
186 | * options sent from the HC-Sender to the | |
187 | * HC-Receiver; option numbers 192 through 255 | |
188 | * are for options sent from the HC-Receiver to | |
189 | * the HC-Sender. | |
7c657876 ACM |
190 | */ |
191 | case 128 ... 191: { | |
192 | const u16 idx = value - options; | |
193 | ||
7690af3f ACM |
194 | if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk, |
195 | opt, len, idx, | |
196 | value) != 0) | |
7c657876 ACM |
197 | goto out_invalid_option; |
198 | } | |
199 | break; | |
200 | case 192 ... 255: { | |
201 | const u16 idx = value - options; | |
202 | ||
7690af3f ACM |
203 | if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk, |
204 | opt, len, idx, | |
205 | value) != 0) | |
7c657876 ACM |
206 | goto out_invalid_option; |
207 | } | |
208 | break; | |
209 | default: | |
7690af3f ACM |
210 | pr_info("DCCP(%p): option %d(len=%d) not " |
211 | "implemented, ignoring\n", | |
7c657876 ACM |
212 | sk, opt, len); |
213 | break; | |
214 | } | |
215 | } | |
216 | ||
217 | return 0; | |
218 | ||
219 | out_invalid_option: | |
220 | DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT); | |
221 | DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR; | |
222 | pr_info("DCCP(%p): invalid option %d, len=%d\n", sk, opt, len); | |
223 | return -1; | |
224 | } | |
225 | ||
226 | static void dccp_encode_value_var(const u32 value, unsigned char *to, | |
227 | const unsigned int len) | |
228 | { | |
229 | if (len > 3) | |
230 | *to++ = (value & 0xFF000000) >> 24; | |
231 | if (len > 2) | |
232 | *to++ = (value & 0xFF0000) >> 16; | |
233 | if (len > 1) | |
234 | *to++ = (value & 0xFF00) >> 8; | |
235 | if (len > 0) | |
236 | *to++ = (value & 0xFF); | |
237 | } | |
238 | ||
239 | static inline int dccp_ndp_len(const int ndp) | |
240 | { | |
241 | return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3; | |
242 | } | |
243 | ||
244 | void dccp_insert_option(struct sock *sk, struct sk_buff *skb, | |
245 | const unsigned char option, | |
246 | const void *value, const unsigned char len) | |
247 | { | |
248 | unsigned char *to; | |
249 | ||
250 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
251 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert " |
252 | "%d option!\n", option); | |
7c657876 ACM |
253 | return; |
254 | } | |
255 | ||
256 | DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2; | |
257 | ||
258 | to = skb_push(skb, len + 2); | |
259 | *to++ = option; | |
260 | *to++ = len + 2; | |
261 | ||
262 | memcpy(to, value, len); | |
263 | } | |
264 | ||
265 | EXPORT_SYMBOL_GPL(dccp_insert_option); | |
266 | ||
267 | static void dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb) | |
268 | { | |
269 | struct dccp_sock *dp = dccp_sk(sk); | |
270 | int ndp = dp->dccps_ndp_count; | |
271 | ||
272 | if (dccp_non_data_packet(skb)) | |
273 | ++dp->dccps_ndp_count; | |
274 | else | |
275 | dp->dccps_ndp_count = 0; | |
276 | ||
277 | if (ndp > 0) { | |
278 | unsigned char *ptr; | |
279 | const int ndp_len = dccp_ndp_len(ndp); | |
280 | const int len = ndp_len + 2; | |
281 | ||
282 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) | |
283 | return; | |
284 | ||
285 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
286 | ||
287 | ptr = skb_push(skb, len); | |
288 | *ptr++ = DCCPO_NDP_COUNT; | |
289 | *ptr++ = len; | |
290 | dccp_encode_value_var(ndp, ptr, ndp_len); | |
291 | } | |
292 | } | |
293 | ||
294 | static inline int dccp_elapsed_time_len(const u32 elapsed_time) | |
295 | { | |
b1c9fe7b | 296 | return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4; |
7c657876 ACM |
297 | } |
298 | ||
299 | void dccp_insert_option_elapsed_time(struct sock *sk, | |
300 | struct sk_buff *skb, | |
301 | u32 elapsed_time) | |
302 | { | |
725ba8ee | 303 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 304 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
305 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
306 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
307 | #endif |
308 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); | |
309 | const int len = 2 + elapsed_time_len; | |
310 | unsigned char *to; | |
311 | ||
312 | /* If elapsed_time == 0... */ | |
313 | if (elapsed_time_len == 2) | |
314 | return; | |
315 | ||
316 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
317 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to " |
318 | "insert elapsed time!\n"); | |
7c657876 ACM |
319 | return; |
320 | } | |
321 | ||
322 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
323 | ||
324 | to = skb_push(skb, len); | |
325 | *to++ = DCCPO_ELAPSED_TIME; | |
326 | *to++ = len; | |
327 | ||
328 | dccp_encode_value_var(elapsed_time, to, elapsed_time_len); | |
329 | ||
330 | dccp_pr_debug("%sELAPSED_TIME=%u, len=%d, seqno=%llu\n", | |
331 | debug_prefix, elapsed_time, | |
f6ccf554 DM |
332 | len, |
333 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); | |
7c657876 ACM |
334 | } |
335 | ||
336 | EXPORT_SYMBOL(dccp_insert_option_elapsed_time); | |
337 | ||
338 | static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb) | |
339 | { | |
340 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 341 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
342 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
343 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
344 | #endif |
345 | struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts; | |
346 | int len = ap->dccpap_buf_vector_len + 2; | |
347 | const u32 elapsed_time = jiffies_to_usecs(jiffies - ap->dccpap_time) / 10; | |
348 | unsigned char *to, *from; | |
349 | ||
350 | if (elapsed_time != 0) | |
351 | dccp_insert_option_elapsed_time(sk, skb, elapsed_time); | |
352 | ||
353 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
354 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to " |
355 | "insert ACK Vector!\n"); | |
7c657876 ACM |
356 | return; |
357 | } | |
358 | ||
359 | /* | |
360 | * XXX: now we have just one ack vector sent record, so | |
361 | * we have to wait for it to be cleared. | |
362 | * | |
363 | * Of course this is not acceptable, but this is just for | |
364 | * basic testing now. | |
365 | */ | |
366 | if (ap->dccpap_ack_seqno != DCCP_MAX_SEQNO + 1) | |
367 | return; | |
368 | ||
369 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
370 | ||
371 | to = skb_push(skb, len); | |
372 | *to++ = DCCPO_ACK_VECTOR_0; | |
373 | *to++ = len; | |
374 | ||
375 | len = ap->dccpap_buf_vector_len; | |
376 | from = ap->dccpap_buf + ap->dccpap_buf_head; | |
377 | ||
378 | /* Check if buf_head wraps */ | |
379 | if (ap->dccpap_buf_head + len > ap->dccpap_buf_len) { | |
7690af3f ACM |
380 | const unsigned int tailsize = (ap->dccpap_buf_len - |
381 | ap->dccpap_buf_head); | |
7c657876 ACM |
382 | |
383 | memcpy(to, from, tailsize); | |
384 | to += tailsize; | |
385 | len -= tailsize; | |
386 | from = ap->dccpap_buf; | |
387 | } | |
388 | ||
389 | memcpy(to, from, len); | |
390 | /* | |
391 | * From draft-ietf-dccp-spec-11.txt: | |
392 | * | |
393 | * For each acknowledgement it sends, the HC-Receiver will add an | |
394 | * acknowledgement record. ack_seqno will equal the HC-Receiver | |
395 | * sequence number it used for the ack packet; ack_ptr will equal | |
7690af3f ACM |
396 | * buf_head; ack_ackno will equal buf_ackno; and ack_nonce will |
397 | * equal buf_nonce. | |
7c657876 ACM |
398 | * |
399 | * This implemention uses just one ack record for now. | |
400 | */ | |
401 | ap->dccpap_ack_seqno = DCCP_SKB_CB(skb)->dccpd_seq; | |
402 | ap->dccpap_ack_ptr = ap->dccpap_buf_head; | |
403 | ap->dccpap_ack_ackno = ap->dccpap_buf_ackno; | |
404 | ap->dccpap_ack_nonce = ap->dccpap_buf_nonce; | |
405 | ap->dccpap_ack_vector_len = ap->dccpap_buf_vector_len; | |
406 | ||
7690af3f ACM |
407 | dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, " |
408 | "ack_ackno=%llu\n", | |
7c657876 | 409 | debug_prefix, ap->dccpap_ack_vector_len, |
f6ccf554 DM |
410 | (unsigned long long) ap->dccpap_ack_seqno, |
411 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
412 | } |
413 | ||
7690af3f ACM |
414 | static inline void dccp_insert_option_timestamp(struct sock *sk, |
415 | struct sk_buff *skb) | |
7c657876 ACM |
416 | { |
417 | const u32 now = htonl(tcp_time_stamp); | |
418 | dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now)); | |
419 | } | |
420 | ||
7690af3f ACM |
421 | static void dccp_insert_option_timestamp_echo(struct sock *sk, |
422 | struct sk_buff *skb) | |
7c657876 ACM |
423 | { |
424 | struct dccp_sock *dp = dccp_sk(sk); | |
725ba8ee | 425 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
426 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
427 | "CLIENT TX opt: " : "server TX opt: "; | |
7c657876 ACM |
428 | #endif |
429 | u32 tstamp_echo; | |
7690af3f ACM |
430 | const u32 elapsed_time = jiffies_to_usecs(jiffies - |
431 | dp->dccps_timestamp_time) / 10; | |
7c657876 ACM |
432 | const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time); |
433 | const int len = 6 + elapsed_time_len; | |
434 | unsigned char *to; | |
435 | ||
436 | if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { | |
7690af3f ACM |
437 | LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert " |
438 | "timestamp echo!\n"); | |
7c657876 ACM |
439 | return; |
440 | } | |
441 | ||
442 | DCCP_SKB_CB(skb)->dccpd_opt_len += len; | |
443 | ||
444 | to = skb_push(skb, len); | |
445 | *to++ = DCCPO_TIMESTAMP_ECHO; | |
446 | *to++ = len; | |
447 | ||
448 | tstamp_echo = htonl(dp->dccps_timestamp_echo); | |
449 | memcpy(to, &tstamp_echo, 4); | |
450 | to += 4; | |
451 | dccp_encode_value_var(elapsed_time, to, elapsed_time_len); | |
452 | ||
453 | dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, seqno=%llu\n", | |
454 | debug_prefix, dp->dccps_timestamp_echo, | |
f6ccf554 DM |
455 | len, |
456 | (unsigned long long) DCCP_SKB_CB(skb)->dccpd_seq); | |
7c657876 ACM |
457 | |
458 | dp->dccps_timestamp_echo = 0; | |
459 | dp->dccps_timestamp_time = 0; | |
460 | } | |
461 | ||
462 | void dccp_insert_options(struct sock *sk, struct sk_buff *skb) | |
463 | { | |
464 | struct dccp_sock *dp = dccp_sk(sk); | |
465 | ||
466 | DCCP_SKB_CB(skb)->dccpd_opt_len = 0; | |
467 | ||
468 | if (dp->dccps_options.dccpo_send_ndp_count) | |
469 | dccp_insert_option_ndp(sk, skb); | |
470 | ||
471 | if (!dccp_packet_without_ack(skb)) { | |
472 | if (dp->dccps_options.dccpo_send_ack_vector && | |
7690af3f ACM |
473 | (dp->dccps_hc_rx_ackpkts->dccpap_buf_ackno != |
474 | DCCP_MAX_SEQNO + 1)) | |
7c657876 ACM |
475 | dccp_insert_option_ack_vector(sk, skb); |
476 | ||
477 | dccp_insert_option_timestamp(sk, skb); | |
478 | if (dp->dccps_timestamp_echo != 0) | |
479 | dccp_insert_option_timestamp_echo(sk, skb); | |
480 | } | |
481 | ||
482 | ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb); | |
483 | ccid_hc_tx_insert_options(dp->dccps_hc_tx_ccid, sk, skb); | |
484 | ||
485 | /* XXX: insert other options when appropriate */ | |
486 | ||
487 | if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { | |
488 | /* The length of all options has to be a multiple of 4 */ | |
489 | int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4; | |
490 | ||
491 | if (padding != 0) { | |
492 | padding = 4 - padding; | |
493 | memset(skb_push(skb, padding), 0, padding); | |
494 | DCCP_SKB_CB(skb)->dccpd_opt_len += padding; | |
495 | } | |
496 | } | |
497 | } | |
498 | ||
a1d3a355 ACM |
499 | struct dccp_ackpkts *dccp_ackpkts_alloc(const unsigned int len, |
500 | const unsigned int __nocast priority) | |
7c657876 ACM |
501 | { |
502 | struct dccp_ackpkts *ap = kmalloc(sizeof(*ap) + len, priority); | |
503 | ||
504 | if (ap != NULL) { | |
725ba8ee | 505 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
506 | memset(ap->dccpap_buf, 0xFF, len); |
507 | #endif | |
7690af3f ACM |
508 | ap->dccpap_buf_len = len; |
509 | ap->dccpap_buf_head = | |
510 | ap->dccpap_buf_tail = | |
511 | ap->dccpap_buf_len - 1; | |
512 | ap->dccpap_buf_ackno = | |
513 | ap->dccpap_ack_ackno = | |
514 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
515 | ap->dccpap_buf_nonce = ap->dccpap_buf_nonce = 0; | |
516 | ap->dccpap_ack_ptr = 0; | |
517 | ap->dccpap_time = 0; | |
7c657876 ACM |
518 | ap->dccpap_buf_vector_len = ap->dccpap_ack_vector_len = 0; |
519 | } | |
520 | ||
521 | return ap; | |
522 | } | |
523 | ||
524 | void dccp_ackpkts_free(struct dccp_ackpkts *ap) | |
525 | { | |
526 | if (ap != NULL) { | |
725ba8ee | 527 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 ACM |
528 | memset(ap, 0xFF, sizeof(*ap) + ap->dccpap_buf_len); |
529 | #endif | |
530 | kfree(ap); | |
531 | } | |
532 | } | |
533 | ||
534 | static inline u8 dccp_ackpkts_state(const struct dccp_ackpkts *ap, | |
535 | const unsigned int index) | |
536 | { | |
537 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_STATE_MASK; | |
538 | } | |
539 | ||
540 | static inline u8 dccp_ackpkts_len(const struct dccp_ackpkts *ap, | |
541 | const unsigned int index) | |
542 | { | |
543 | return ap->dccpap_buf[index] & DCCP_ACKPKTS_LEN_MASK; | |
544 | } | |
545 | ||
546 | /* | |
547 | * If several packets are missing, the HC-Receiver may prefer to enter multiple | |
548 | * bytes with run length 0, rather than a single byte with a larger run length; | |
549 | * this simplifies table updates if one of the missing packets arrives. | |
550 | */ | |
551 | static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap, | |
552 | const unsigned int packets, | |
553 | const unsigned char state) | |
554 | { | |
555 | unsigned int gap; | |
556 | signed long new_head; | |
557 | ||
558 | if (ap->dccpap_buf_vector_len + packets > ap->dccpap_buf_len) | |
559 | return -ENOBUFS; | |
560 | ||
561 | gap = packets - 1; | |
562 | new_head = ap->dccpap_buf_head - packets; | |
563 | ||
564 | if (new_head < 0) { | |
565 | if (gap > 0) { | |
566 | memset(ap->dccpap_buf, DCCP_ACKPKTS_STATE_NOT_RECEIVED, | |
567 | gap + new_head + 1); | |
568 | gap = -new_head; | |
569 | } | |
570 | new_head += ap->dccpap_buf_len; | |
571 | } | |
572 | ||
573 | ap->dccpap_buf_head = new_head; | |
574 | ||
575 | if (gap > 0) | |
576 | memset(ap->dccpap_buf + ap->dccpap_buf_head + 1, | |
577 | DCCP_ACKPKTS_STATE_NOT_RECEIVED, gap); | |
578 | ||
579 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
580 | ap->dccpap_buf_vector_len += packets; | |
581 | return 0; | |
582 | } | |
583 | ||
584 | /* | |
585 | * Implements the draft-ietf-dccp-spec-11.txt Appendix A | |
586 | */ | |
587 | int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state) | |
588 | { | |
589 | /* | |
590 | * Check at the right places if the buffer is full, if it is, tell the | |
591 | * caller to start dropping packets till the HC-Sender acks our ACK | |
592 | * vectors, when we will free up space in dccpap_buf. | |
593 | * | |
594 | * We may well decide to do buffer compression, etc, but for now lets | |
595 | * just drop. | |
596 | * | |
597 | * From Appendix A: | |
598 | * | |
7690af3f ACM |
599 | * Of course, the circular buffer may overflow, either when the |
600 | * HC-Sender is sending data at a very high rate, when the | |
601 | * HC-Receiver's acknowledgements are not reaching the HC-Sender, | |
602 | * or when the HC-Sender is forgetting to acknowledge those acks | |
603 | * (so the HC-Receiver is unable to clean up old state). In this | |
604 | * case, the HC-Receiver should either compress the buffer (by | |
605 | * increasing run lengths when possible), transfer its state to | |
606 | * a larger buffer, or, as a last resort, drop all received | |
607 | * packets, without processing them whatsoever, until its buffer | |
608 | * shrinks again. | |
7c657876 ACM |
609 | */ |
610 | ||
611 | /* See if this is the first ackno being inserted */ | |
612 | if (ap->dccpap_buf_vector_len == 0) { | |
613 | ap->dccpap_buf[ap->dccpap_buf_head] = state; | |
614 | ap->dccpap_buf_vector_len = 1; | |
615 | } else if (after48(ackno, ap->dccpap_buf_ackno)) { | |
7690af3f ACM |
616 | const u64 delta = dccp_delta_seqno(ap->dccpap_buf_ackno, |
617 | ackno); | |
7c657876 ACM |
618 | |
619 | /* | |
7690af3f ACM |
620 | * Look if the state of this packet is the same as the |
621 | * previous ackno and if so if we can bump the head len. | |
7c657876 ACM |
622 | */ |
623 | if (delta == 1 && | |
624 | dccp_ackpkts_state(ap, ap->dccpap_buf_head) == state && | |
7690af3f ACM |
625 | (dccp_ackpkts_len(ap, ap->dccpap_buf_head) < |
626 | DCCP_ACKPKTS_LEN_MASK)) | |
7c657876 ACM |
627 | ap->dccpap_buf[ap->dccpap_buf_head]++; |
628 | else if (dccp_ackpkts_set_buf_head_state(ap, delta, state)) | |
629 | return -ENOBUFS; | |
630 | } else { | |
631 | /* | |
632 | * A.1.2. Old Packets | |
633 | * | |
7690af3f ACM |
634 | * When a packet with Sequence Number S arrives, and |
635 | * S <= buf_ackno, the HC-Receiver will scan the table | |
636 | * for the byte corresponding to S. (Indexing structures | |
637 | * could reduce the complexity of this scan.) | |
7c657876 ACM |
638 | */ |
639 | u64 delta = dccp_delta_seqno(ackno, ap->dccpap_buf_ackno); | |
640 | unsigned int index = ap->dccpap_buf_head; | |
641 | ||
642 | while (1) { | |
643 | const u8 len = dccp_ackpkts_len(ap, index); | |
644 | const u8 state = dccp_ackpkts_state(ap, index); | |
645 | /* | |
7690af3f ACM |
646 | * valid packets not yet in dccpap_buf have a reserved |
647 | * entry, with a len equal to 0. | |
7c657876 ACM |
648 | */ |
649 | if (state == DCCP_ACKPKTS_STATE_NOT_RECEIVED && | |
7690af3f ACM |
650 | len == 0 && delta == 0) { /* Found our |
651 | reserved seat! */ | |
f6ccf554 DM |
652 | dccp_pr_debug("Found %llu reserved seat!\n", |
653 | (unsigned long long) ackno); | |
7c657876 ACM |
654 | ap->dccpap_buf[index] = state; |
655 | goto out; | |
656 | } | |
657 | /* len == 0 means one packet */ | |
658 | if (delta < len + 1) | |
659 | goto out_duplicate; | |
660 | ||
661 | delta -= len + 1; | |
662 | if (++index == ap->dccpap_buf_len) | |
663 | index = 0; | |
664 | } | |
665 | } | |
666 | ||
667 | ap->dccpap_buf_ackno = ackno; | |
668 | ap->dccpap_time = jiffies; | |
669 | out: | |
670 | dccp_pr_debug(""); | |
671 | dccp_ackpkts_print(ap); | |
672 | return 0; | |
673 | ||
674 | out_duplicate: | |
675 | /* Duplicate packet */ | |
7690af3f ACM |
676 | dccp_pr_debug("Received a dup or already considered lost " |
677 | "packet: %llu\n", (unsigned long long) ackno); | |
7c657876 ACM |
678 | return -EILSEQ; |
679 | } | |
680 | ||
725ba8ee | 681 | #ifdef CONFIG_IP_DCCP_DEBUG |
7690af3f ACM |
682 | void dccp_ackvector_print(const u64 ackno, const unsigned char *vector, |
683 | int len) | |
7c657876 ACM |
684 | { |
685 | if (!dccp_debug) | |
686 | return; | |
687 | ||
f6ccf554 DM |
688 | printk("ACK vector len=%d, ackno=%llu |", len, |
689 | (unsigned long long) ackno); | |
7c657876 ACM |
690 | |
691 | while (len--) { | |
692 | const u8 state = (*vector & DCCP_ACKPKTS_STATE_MASK) >> 6; | |
693 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
694 | ||
695 | printk("%d,%d|", state, rl); | |
696 | ++vector; | |
697 | } | |
698 | ||
699 | printk("\n"); | |
700 | } | |
701 | ||
702 | void dccp_ackpkts_print(const struct dccp_ackpkts *ap) | |
703 | { | |
704 | dccp_ackvector_print(ap->dccpap_buf_ackno, | |
705 | ap->dccpap_buf + ap->dccpap_buf_head, | |
706 | ap->dccpap_buf_vector_len); | |
707 | } | |
708 | #endif | |
709 | ||
710 | static void dccp_ackpkts_trow_away_ack_record(struct dccp_ackpkts *ap) | |
711 | { | |
712 | /* | |
713 | * As we're keeping track of the ack vector size | |
714 | * (dccpap_buf_vector_len) and the sent ack vector size | |
715 | * (dccpap_ack_vector_len) we don't need dccpap_buf_tail at all, but | |
7690af3f ACM |
716 | * keep this code here as in the future we'll implement a vector of |
717 | * ack records, as suggested in draft-ietf-dccp-spec-11.txt | |
718 | * Appendix A. -acme | |
7c657876 ACM |
719 | */ |
720 | #if 0 | |
721 | ap->dccpap_buf_tail = ap->dccpap_ack_ptr + 1; | |
722 | if (ap->dccpap_buf_tail >= ap->dccpap_buf_len) | |
723 | ap->dccpap_buf_tail -= ap->dccpap_buf_len; | |
724 | #endif | |
725 | ap->dccpap_buf_vector_len -= ap->dccpap_ack_vector_len; | |
726 | } | |
727 | ||
728 | void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap, struct sock *sk, | |
729 | u64 ackno) | |
730 | { | |
731 | /* Check if we actually sent an ACK vector */ | |
732 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
733 | return; | |
734 | ||
735 | if (ackno == ap->dccpap_ack_seqno) { | |
725ba8ee | 736 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 737 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
738 | const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ? |
739 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 740 | #endif |
7690af3f ACM |
741 | dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, " |
742 | "ack_ackno=%llu, ACKED!\n", | |
7c657876 | 743 | debug_prefix, 1, |
f6ccf554 DM |
744 | (unsigned long long) ap->dccpap_ack_seqno, |
745 | (unsigned long long) ap->dccpap_ack_ackno); | |
7c657876 ACM |
746 | dccp_ackpkts_trow_away_ack_record(ap); |
747 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
748 | } | |
749 | } | |
750 | ||
751 | static void dccp_ackpkts_check_rcv_ackvector(struct dccp_ackpkts *ap, | |
752 | struct sock *sk, u64 ackno, | |
753 | const unsigned char len, | |
754 | const unsigned char *vector) | |
755 | { | |
756 | unsigned char i; | |
757 | ||
758 | /* Check if we actually sent an ACK vector */ | |
759 | if (ap->dccpap_ack_seqno == DCCP_MAX_SEQNO + 1) | |
760 | return; | |
761 | /* | |
7690af3f ACM |
762 | * We're in the receiver half connection, so if the received an ACK |
763 | * vector ackno (e.g. 50) before dccpap_ack_seqno (e.g. 52), we're | |
764 | * not interested. | |
7c657876 ACM |
765 | * |
766 | * Extra explanation with example: | |
767 | * | |
768 | * if we received an ACK vector with ackno 50, it can only be acking | |
769 | * 50, 49, 48, etc, not 52 (the seqno for the ACK vector we sent). | |
770 | */ | |
7690af3f | 771 | /* dccp_pr_debug("is %llu < %llu? ", ackno, ap->dccpap_ack_seqno); */ |
7c657876 | 772 | if (before48(ackno, ap->dccpap_ack_seqno)) { |
7690af3f | 773 | /* dccp_pr_debug_cat("yes\n"); */ |
7c657876 ACM |
774 | return; |
775 | } | |
7690af3f | 776 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
777 | |
778 | i = len; | |
779 | while (i--) { | |
780 | const u8 rl = (*vector & DCCP_ACKPKTS_LEN_MASK); | |
781 | u64 ackno_end_rl; | |
782 | ||
783 | dccp_set_seqno(&ackno_end_rl, ackno - rl); | |
784 | ||
7690af3f ACM |
785 | /* |
786 | * dccp_pr_debug("is %llu <= %llu <= %llu? ", ackno_end_rl, | |
787 | * ap->dccpap_ack_seqno, ackno); | |
788 | */ | |
7c657876 | 789 | if (between48(ap->dccpap_ack_seqno, ackno_end_rl, ackno)) { |
7690af3f ACM |
790 | const u8 state = (*vector & |
791 | DCCP_ACKPKTS_STATE_MASK) >> 6; | |
792 | /* dccp_pr_debug_cat("yes\n"); */ | |
7c657876 ACM |
793 | |
794 | if (state != DCCP_ACKPKTS_STATE_NOT_RECEIVED) { | |
725ba8ee | 795 | #ifdef CONFIG_IP_DCCP_DEBUG |
7c657876 | 796 | struct dccp_sock *dp = dccp_sk(sk); |
7690af3f ACM |
797 | const char *debug_prefix = |
798 | dp->dccps_role == DCCP_ROLE_CLIENT ? | |
799 | "CLIENT rx ack: " : "server rx ack: "; | |
7c657876 | 800 | #endif |
7690af3f ACM |
801 | dccp_pr_debug("%sACK vector 0, len=%d, " |
802 | "ack_seqno=%llu, ack_ackno=%llu, " | |
803 | "ACKED!\n", | |
7c657876 | 804 | debug_prefix, len, |
f6ccf554 DM |
805 | (unsigned long long) |
806 | ap->dccpap_ack_seqno, | |
807 | (unsigned long long) | |
808 | ap->dccpap_ack_ackno); | |
7c657876 ACM |
809 | dccp_ackpkts_trow_away_ack_record(ap); |
810 | } | |
811 | /* | |
7690af3f ACM |
812 | * If dccpap_ack_seqno was not received, no problem |
813 | * we'll send another ACK vector. | |
7c657876 ACM |
814 | */ |
815 | ap->dccpap_ack_seqno = DCCP_MAX_SEQNO + 1; | |
816 | break; | |
817 | } | |
7690af3f | 818 | /* dccp_pr_debug_cat("no\n"); */ |
7c657876 ACM |
819 | |
820 | dccp_set_seqno(&ackno, ackno_end_rl - 1); | |
821 | ++vector; | |
822 | } | |
823 | } |