1 | /* |
1 | /* |
2 | vpn_dns.C -- handle the dns tunnel part of the protocol. |
2 | vpn_dns.C -- handle the dns tunnel part of the protocol. |
3 | Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> |
3 | Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de> |
4 | |
4 | |
5 | This file is part of GVPE. |
5 | This file is part of GVPE. |
6 | |
6 | |
7 | GVPE is free software; you can redistribute it and/or modify |
7 | GVPE is free software; you can redistribute it and/or modify it |
8 | it under the terms of the GNU General Public License as published by |
8 | under the terms of the GNU General Public License as published by the |
9 | the Free Software Foundation; either version 2 of the License, or |
9 | Free Software Foundation; either version 3 of the License, or (at your |
10 | (at your option) any later version. |
10 | option) any later version. |
11 | |
11 | |
12 | This program is distributed in the hope that it will be useful, |
12 | This program is distributed in the hope that it will be useful, but |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
15 | GNU General Public License for more details. |
15 | Public License for more details. |
16 | |
16 | |
17 | You should have received a copy of the GNU General Public License |
17 | You should have received a copy of the GNU General Public License along |
18 | along with gvpe; if not, write to the Free Software |
18 | with this program; if not, see <http://www.gnu.org/licenses/>. |
19 | Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | |
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20 | Additional permission under GNU GPL version 3 section 7 |
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21 | |
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22 | If you modify this Program, or any covered work, by linking or |
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23 | combining it with the OpenSSL project's OpenSSL library (or a modified |
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24 | version of that library), containing parts covered by the terms of the |
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25 | OpenSSL or SSLeay licenses, the licensors of this Program grant you |
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26 | additional permission to convey the resulting work. Corresponding |
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27 | Source for a non-source form of such a combination shall include the |
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28 | source code for the parts of OpenSSL used as well as that of the |
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29 | covered work. |
20 | */ |
30 | */ |
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31 | |
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32 | // TODO: EDNS0 option to increase dns mtu? |
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33 | // TODO: re-write dns packet parsing/creation using a safe mem-buffer |
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34 | // to ensure no buffer overflows or similar problems. |
21 | |
35 | |
22 | #include "config.h" |
36 | #include "config.h" |
23 | |
37 | |
24 | #if ENABLE_DNS |
38 | #if ENABLE_DNS |
25 | |
39 | |
… | |
… | |
38 | #include <unistd.h> |
52 | #include <unistd.h> |
39 | #include <fcntl.h> |
53 | #include <fcntl.h> |
40 | |
54 | |
41 | #include <map> |
55 | #include <map> |
42 | |
56 | |
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57 | #include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */ |
43 | #include <gmp.h> |
58 | #include <gmp.h> |
44 | |
59 | |
45 | #include "netcompat.h" |
60 | #include "netcompat.h" |
46 | |
61 | |
47 | #include "vpn.h" |
62 | #include "vpn.h" |
48 | |
63 | |
49 | #define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data |
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50 | #define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data |
64 | #define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data |
51 | #define ACTIVITY_INTERVAL 5. |
65 | #define ACTIVITY_INTERVAL 5. |
52 | |
66 | |
53 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
67 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
54 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
68 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
55 | |
69 | |
56 | #define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests |
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57 | #define MAX_SEND_INTERVAL 0.5 // optimistic? |
70 | #define MAX_SEND_INTERVAL 2. // optimistic? |
58 | |
71 | |
59 | #define MAX_OUTSTANDING 10 // max. outstanding requests |
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60 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
72 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
61 | #define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
73 | #define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
62 | |
74 | |
63 | #define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well |
75 | #define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well |
64 | // 240 leaves about 4 bytes of server reply data |
76 | // 240 leaves about 4 bytes of server reply data |
65 | // every two request bytes less give room for one reply byte |
77 | // every request byte less give room for two reply bytes |
66 | |
78 | |
67 | #define SEQNO_MASK 0x3fff |
79 | #define SEQNO_MASK 0x3fff |
68 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
80 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
69 | |
81 | |
70 | #define MAX_LBL_SIZE 63 |
82 | #define MAX_LBL_SIZE 63 |
71 | #define MAX_PKT_SIZE 512 |
83 | #define MAX_PKT_SIZE 512 |
72 | |
84 | |
73 | #define RR_TYPE_A 1 |
85 | #define RR_TYPE_A 1 |
74 | #define RR_TYPE_NULL 10 |
86 | #define RR_TYPE_NULL 10 |
75 | #define RR_TYPE_TXT 16 |
87 | #define RR_TYPE_TXT 16 |
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88 | #define RR_TYPE_AAAA 28 |
76 | #define RR_TYPE_ANY 255 |
89 | #define RR_TYPE_ANY 255 |
77 | |
90 | |
78 | #define RR_CLASS_IN 1 |
91 | #define RR_CLASS_IN 1 |
79 | |
92 | |
80 | #define CMD_IP_1 207 |
93 | #define CMD_IP_1 207 |
… | |
… | |
104 | memset (enc, (char) 0, 256); |
117 | memset (enc, (char) 0, 256); |
105 | memset (dec, (char)INVALID, 256); |
118 | memset (dec, (char)INVALID, 256); |
106 | |
119 | |
107 | for (size = 0; cmap [size]; size++) |
120 | for (size = 0; cmap [size]; size++) |
108 | { |
121 | { |
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122 | char c = cmap [size]; |
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123 | |
109 | enc [size] = cmap [size]; |
124 | enc [size] = c; |
110 | dec [(u8)enc [size]] = size; |
125 | dec [(u8)c] = size; |
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126 | |
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127 | // allow lowercase/uppercase aliases if possible |
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128 | if (c >= 'A' && c <= 'Z' && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size; |
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129 | if (c >= 'a' && c <= 'z' && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size; |
111 | } |
130 | } |
112 | |
131 | |
113 | assert (size < 256); |
132 | assert (size < 256); |
114 | } |
133 | } |
115 | |
134 | |
… | |
… | |
155 | enc_len [len] = n; |
174 | enc_len [len] = n; |
156 | dec_len [n] = len; |
175 | dec_len [n] = len; |
157 | } |
176 | } |
158 | } |
177 | } |
159 | |
178 | |
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179 | unsigned int |
160 | unsigned int basecoder::encode_len (unsigned int len) |
180 | basecoder::encode_len (unsigned int len) |
161 | { |
181 | { |
162 | return enc_len [len]; |
182 | return enc_len [len]; |
163 | } |
183 | } |
164 | |
184 | |
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185 | unsigned int |
165 | unsigned int basecoder::decode_len (unsigned int len) |
186 | basecoder::decode_len (unsigned int len) |
166 | { |
187 | { |
167 | while (len && !dec_len [len]) |
188 | while (len && !dec_len [len]) |
168 | --len; |
189 | --len; |
169 | |
190 | |
170 | return dec_len [len]; |
191 | return dec_len [len]; |
171 | } |
192 | } |
172 | |
193 | |
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194 | unsigned int |
173 | unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) |
195 | basecoder::encode (char *dst, u8 *src, unsigned int len) |
174 | { |
196 | { |
175 | if (!len || len > MAX_DEC_LEN) |
197 | if (!len || len > MAX_DEC_LEN) |
176 | return 0; |
198 | return 0; |
177 | |
199 | |
178 | int elen = encode_len (len); |
200 | int elen = encode_len (len); |
… | |
… | |
197 | *dst++ = cmap.encode [dst_ [i]]; |
219 | *dst++ = cmap.encode [dst_ [i]]; |
198 | |
220 | |
199 | return elen; |
221 | return elen; |
200 | } |
222 | } |
201 | |
223 | |
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224 | unsigned int |
202 | unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) |
225 | basecoder::decode (u8 *dst, char *src, unsigned int len) |
203 | { |
226 | { |
204 | if (!len || len > MAX_ENC_LEN) |
227 | if (!len || len > MAX_ENC_LEN) |
205 | return 0; |
228 | return 0; |
206 | |
229 | |
207 | u8 src_ [MAX_ENC_LEN]; |
230 | u8 src_ [MAX_ENC_LEN]; |
… | |
… | |
265 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
288 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
266 | |
289 | |
267 | ///////////////////////////////////////////////////////////////////////////// |
290 | ///////////////////////////////////////////////////////////////////////////// |
268 | |
291 | |
269 | #define HDRSIZE 6 |
292 | #define HDRSIZE 6 |
270 | |
293 | |
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294 | inline void |
271 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
295 | encode_header (char *data, int clientid, int seqno, int retry = 0) |
272 | { |
296 | { |
273 | seqno &= SEQNO_MASK; |
297 | seqno &= SEQNO_MASK; |
274 | |
298 | |
275 | u8 hdr[3] = { |
299 | u8 hdr[3] = { |
276 | clientid, |
300 | clientid, |
… | |
… | |
281 | assert (clientid < 256); |
305 | assert (clientid < 256); |
282 | |
306 | |
283 | cdc26.encode (data, hdr, 3); |
307 | cdc26.encode (data, hdr, 3); |
284 | } |
308 | } |
285 | |
309 | |
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310 | inline void |
286 | inline void decode_header (char *data, int &clientid, int &seqno) |
311 | decode_header (char *data, int &clientid, int &seqno) |
287 | { |
312 | { |
288 | u8 hdr[3]; |
313 | u8 hdr[3]; |
289 | |
314 | |
290 | cdc26.decode (hdr, data, HDRSIZE); |
315 | cdc26.decode (hdr, data, HDRSIZE); |
291 | |
316 | |
… | |
… | |
324 | byte_stream::~byte_stream () |
349 | byte_stream::~byte_stream () |
325 | { |
350 | { |
326 | delete data; |
351 | delete data; |
327 | } |
352 | } |
328 | |
353 | |
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354 | void |
329 | void byte_stream::remove (int count) |
355 | byte_stream::remove (int count) |
330 | { |
356 | { |
331 | if (count > fill) |
357 | if (count > fill) |
332 | assert (count <= fill); |
358 | assert (count <= fill); |
333 | |
359 | |
334 | memmove (data, data + count, fill -= count); |
360 | memmove (data, data + count, fill -= count); |
335 | } |
361 | } |
336 | |
362 | |
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363 | bool |
337 | bool byte_stream::put (u8 *data, unsigned int datalen) |
364 | byte_stream::put (u8 *data, unsigned int datalen) |
338 | { |
365 | { |
339 | if (maxsize - fill < datalen) |
366 | if (maxsize - fill < datalen) |
340 | return false; |
367 | return false; |
341 | |
368 | |
342 | memcpy (this->data + fill, data, datalen); fill += datalen; |
369 | memcpy (this->data + fill, data, datalen); fill += datalen; |
343 | |
370 | |
344 | return true; |
371 | return true; |
345 | } |
372 | } |
346 | |
373 | |
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374 | bool |
347 | bool byte_stream::put (vpn_packet *pkt) |
375 | byte_stream::put (vpn_packet *pkt) |
348 | { |
376 | { |
349 | if (maxsize - fill < pkt->len + 2) |
377 | if (maxsize - fill < pkt->len + 2) |
350 | return false; |
378 | return false; |
351 | |
379 | |
352 | data [fill++] = pkt->len >> 8; |
380 | data [fill++] = pkt->len >> 8; |
… | |
… | |
409 | struct dns_cfg |
437 | struct dns_cfg |
410 | { |
438 | { |
411 | static int next_uid; |
439 | static int next_uid; |
412 | |
440 | |
413 | u8 id1, id2, id3, id4; |
441 | u8 id1, id2, id3, id4; |
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442 | |
414 | u8 version; |
443 | u8 version; |
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444 | u8 flags; |
415 | u8 rrtype; |
445 | u8 rrtype; |
416 | u8 flags; |
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417 | u8 def_ttl; |
446 | u8 def_ttl; |
418 | u8 rcv_cdc; |
447 | |
419 | u8 snd_cdc; |
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420 | u16 max_size; |
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421 | u16 client; |
448 | u16 client; |
422 | u16 uid; // to make request unique |
449 | u16 uid; // to make request unique |
423 | |
450 | |
424 | u8 reserved[8]; |
451 | u16 max_size; |
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452 | u8 seq_cdc; |
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453 | u8 req_cdc; |
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454 | |
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455 | u8 rep_cdc; |
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456 | u8 delay; // time in 0.01s units that the server may delay replying packets |
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457 | u8 r3, r4; |
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458 | |
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459 | u8 r5, r6, r7, r8; |
425 | |
460 | |
426 | void reset (int clientid); |
461 | void reset (int clientid); |
427 | bool valid (); |
462 | bool valid (); |
428 | }; |
463 | }; |
429 | |
464 | |
430 | int dns_cfg::next_uid; |
465 | int dns_cfg::next_uid; |
431 | |
466 | |
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467 | void |
432 | void dns_cfg::reset (int clientid) |
468 | dns_cfg::reset (int clientid) |
433 | { |
469 | { |
434 | id1 = 'G'; |
470 | id1 = 'G'; |
435 | id2 = 'V'; |
471 | id2 = 'V'; |
436 | id3 = 'P'; |
472 | id3 = 'P'; |
437 | id4 = 'E'; |
473 | id4 = 'E'; |
438 | |
474 | |
439 | version = 1; |
475 | version = 1; |
440 | |
476 | |
441 | rrtype = RR_TYPE_TXT; |
477 | rrtype = RR_TYPE_TXT; |
442 | flags = 0; |
478 | flags = 0; |
443 | def_ttl = 1; |
479 | def_ttl = 0; |
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480 | seq_cdc = 26; |
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481 | req_cdc = 62; |
444 | rcv_cdc = 0; |
482 | rep_cdc = 0; |
445 | snd_cdc = 62; |
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446 | max_size = ntohs (MAX_PKT_SIZE); |
483 | max_size = htons (MAX_PKT_SIZE); |
447 | client = ntohs (clientid); |
484 | client = htons (clientid); |
448 | uid = next_uid++; |
485 | uid = next_uid++; |
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486 | delay = 0; |
449 | |
487 | |
450 | memset (reserved, 0, 8); |
488 | r3 = r4 = 0; |
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489 | r4 = r5 = r6 = r7 = 0; |
451 | } |
490 | } |
452 | |
491 | |
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492 | bool |
453 | bool dns_cfg::valid () |
493 | dns_cfg::valid () |
454 | { |
494 | { |
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495 | // although the protocol itself allows for some configurability, |
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496 | // only the following encoding/decoding settings are implemented. |
455 | return id1 == 'G' |
497 | return id1 == 'G' |
456 | && id2 == 'V' |
498 | && id2 == 'V' |
457 | && id3 == 'P' |
499 | && id3 == 'P' |
458 | && id4 == 'E' |
500 | && id4 == 'E' |
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501 | && seq_cdc == 26 |
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502 | && req_cdc == 62 |
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503 | && rep_cdc == 0 |
459 | && version == 1 |
504 | && version == 1; |
460 | && flags == 0 |
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461 | && rcv_cdc == 0 |
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462 | && snd_cdc == 62 |
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463 | && max_size == ntohs (MAX_PKT_SIZE); |
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464 | } |
505 | } |
465 | |
506 | |
466 | struct dns_packet : net_packet |
507 | struct dns_packet : net_packet |
467 | { |
508 | { |
468 | u16 id; |
509 | u16 id; |
469 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
510 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
470 | u16 qdcount, ancount, nscount, arcount; |
511 | u16 qdcount, ancount, nscount, arcount; |
471 | |
512 | |
472 | u8 data[MAXSIZE - 6 * 2]; |
513 | u8 data [MAXSIZE - 6 * 2]; |
473 | |
514 | |
474 | int decode_label (char *data, int size, int &offs); |
515 | int decode_label (char *data, int size, int &offs); |
475 | }; |
516 | }; |
476 | |
517 | |
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518 | int |
477 | int dns_packet::decode_label (char *data, int size, int &offs) |
519 | dns_packet::decode_label (char *data, int size, int &offs) |
478 | { |
520 | { |
479 | char *orig = data; |
521 | char *orig = data; |
480 | |
522 | |
481 | memset (data, 0, size); |
523 | memset (data, 0, size); |
482 | |
524 | |
… | |
… | |
508 | return data - orig; |
550 | return data - orig; |
509 | } |
551 | } |
510 | |
552 | |
511 | ///////////////////////////////////////////////////////////////////////////// |
553 | ///////////////////////////////////////////////////////////////////////////// |
512 | |
554 | |
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555 | static |
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556 | u16 next_id () |
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557 | { |
513 | static u16 dns_id = 0; // TODO: should be per-vpn |
558 | static u16 dns_id = 0; // TODO: should be per-vpn |
514 | |
559 | |
515 | static u16 next_id () |
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516 | { |
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517 | if (!dns_id) |
560 | if (!dns_id) |
518 | dns_id = time (0); |
561 | dns_id = time (0); |
519 | |
562 | |
520 | // the simplest lsfr with periodicity 65535 i could find |
563 | // the simplest lsfr with periodicity 65535 i could find |
521 | dns_id = (dns_id << 1) |
564 | dns_id = (dns_id << 1) |
… | |
… | |
539 | |
582 | |
540 | bool established; |
583 | bool established; |
541 | |
584 | |
542 | tstamp last_received; |
585 | tstamp last_received; |
543 | tstamp last_sent; |
586 | tstamp last_sent; |
544 | double last_latency; |
587 | double min_latency; |
545 | double poll_interval, send_interval; |
588 | double poll_interval, send_interval; |
546 | |
589 | |
547 | vector<dns_rcv *> rcvpq; |
590 | vector<dns_rcv *> rcvpq; |
548 | |
591 | |
549 | byte_stream rcvdq; int rcvseq; |
592 | byte_stream rcvdq; int rcvseq; int repseq; |
550 | byte_stream snddq; int sndseq; |
593 | byte_stream snddq; int sndseq; |
551 | |
594 | |
552 | void time_cb (time_watcher &w); time_watcher tw; |
595 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
553 | void receive_rep (dns_rcv *r); |
596 | void receive_rep (dns_rcv *r); |
554 | |
597 | |
555 | dns_connection (connection *c); |
598 | dns_connection (connection *c); |
556 | ~dns_connection (); |
599 | ~dns_connection (); |
557 | }; |
600 | }; |
… | |
… | |
576 | : dns (dns) |
619 | : dns (dns) |
577 | { |
620 | { |
578 | timeout = 0; |
621 | timeout = 0; |
579 | retry = 0; |
622 | retry = 0; |
580 | seqno = 0; |
623 | seqno = 0; |
581 | sent = NOW; |
624 | sent = ev_now (); |
582 | stdhdr = false; |
625 | stdhdr = false; |
583 | |
626 | |
584 | pkt = new dns_packet; |
627 | pkt = new dns_packet; |
585 | |
628 | |
586 | pkt->id = next_id (); |
629 | pkt->id = next_id (); |
… | |
… | |
589 | dns_snd::~dns_snd () |
632 | dns_snd::~dns_snd () |
590 | { |
633 | { |
591 | delete pkt; |
634 | delete pkt; |
592 | } |
635 | } |
593 | |
636 | |
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637 | static void |
594 | static void append_domain (dns_packet &pkt, int &offs, const char *domain) |
638 | append_domain (dns_packet &pkt, int &offs, const char *domain) |
595 | { |
639 | { |
596 | // add tunnel domain |
640 | // add tunnel domain |
597 | for (;;) |
641 | for (;;) |
598 | { |
642 | { |
599 | const char *end = strchr (domain, '.'); |
643 | const char *end = strchr (domain, '.'); |
… | |
… | |
612 | |
656 | |
613 | domain = end + 1; |
657 | domain = end + 1; |
614 | } |
658 | } |
615 | } |
659 | } |
616 | |
660 | |
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661 | void |
617 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
662 | dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
618 | { |
663 | { |
619 | stdhdr = true; |
664 | stdhdr = true; |
620 | this->seqno = seqno; |
665 | this->seqno = seqno; |
621 | |
666 | |
622 | timeout = NOW + INITIAL_TIMEOUT; |
667 | timeout = ev_now () + INITIAL_TIMEOUT; |
623 | |
668 | |
624 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
669 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
625 | pkt->qdcount = htons (1); |
670 | pkt->qdcount = htons (1); |
626 | |
671 | |
627 | int offs = 6*2; |
672 | int offs = 6*2; |
… | |
… | |
660 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
705 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
661 | |
706 | |
662 | pkt->len = offs; |
707 | pkt->len = offs; |
663 | } |
708 | } |
664 | |
709 | |
|
|
710 | void |
665 | void dns_snd::gen_syn_req () |
711 | dns_snd::gen_syn_req () |
666 | { |
712 | { |
667 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
713 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
668 | |
|
|
669 | printf ("send syn\n");//D |
|
|
670 | |
714 | |
671 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
715 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
672 | pkt->qdcount = htons (1); |
716 | pkt->qdcount = htons (1); |
673 | |
717 | |
674 | int offs = 6 * 2; |
718 | int offs = 6 * 2; |
… | |
… | |
713 | ///////////////////////////////////////////////////////////////////////////// |
757 | ///////////////////////////////////////////////////////////////////////////// |
714 | |
758 | |
715 | dns_connection::dns_connection (connection *c) |
759 | dns_connection::dns_connection (connection *c) |
716 | : c (c) |
760 | : c (c) |
717 | , rcvdq (MAX_BACKLOG * 2) |
761 | , rcvdq (MAX_BACKLOG * 2) |
718 | , snddq (MAX_BACKLOG * 2) |
762 | , snddq (MAX_BACKLOG) |
719 | , tw (this, &dns_connection::time_cb) |
|
|
720 | { |
763 | { |
|
|
764 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
|
|
765 | |
721 | vpn = c->vpn; |
766 | vpn = c->vpn; |
722 | |
767 | |
723 | established = false; |
768 | established = false; |
724 | |
769 | |
725 | rcvseq = sndseq = 0; |
770 | rcvseq = repseq = sndseq = 0; |
726 | |
771 | |
727 | last_sent = last_received = 0; |
772 | last_sent = last_received = 0; |
728 | poll_interval = MIN_POLL_INTERVAL; |
773 | poll_interval = 0.5; // starting here |
729 | send_interval = 0.5; // starting rate |
774 | send_interval = 0.5; // starting rate |
730 | last_latency = INITIAL_TIMEOUT; |
775 | min_latency = INITIAL_TIMEOUT; |
731 | } |
776 | } |
732 | |
777 | |
733 | dns_connection::~dns_connection () |
778 | dns_connection::~dns_connection () |
734 | { |
779 | { |
735 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
780 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
736 | i != rcvpq.end (); |
781 | i != rcvpq.end (); |
737 | ++i) |
782 | ++i) |
738 | delete *i; |
783 | delete *i; |
739 | } |
784 | } |
740 | |
785 | |
|
|
786 | void |
741 | void dns_connection::receive_rep (dns_rcv *r) |
787 | dns_connection::receive_rep (dns_rcv *r) |
742 | { |
788 | { |
743 | if (r->datalen) |
789 | if (r->datalen) |
744 | { |
790 | { |
745 | last_received = NOW; |
791 | last_received = ev_now (); |
746 | tw.trigger (); |
792 | tw (); |
747 | |
793 | |
748 | poll_interval = send_interval; |
794 | poll_interval = send_interval; |
749 | } |
795 | } |
750 | else |
796 | else |
751 | { |
797 | { |
752 | poll_interval *= 1.5; |
798 | poll_interval *= 1.5; |
|
|
799 | |
753 | if (poll_interval > MAX_POLL_INTERVAL) |
800 | if (poll_interval > MAX_POLL_INTERVAL) |
754 | poll_interval = MAX_POLL_INTERVAL; |
801 | poll_interval = MAX_POLL_INTERVAL; |
755 | } |
802 | } |
756 | |
803 | |
757 | rcvpq.push_back (r); |
804 | rcvpq.push_back (r); |
… | |
… | |
760 | |
807 | |
761 | // find next packet |
808 | // find next packet |
762 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
809 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
763 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
810 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
764 | { |
811 | { |
|
|
812 | //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D |
765 | // enter the packet into our input stream |
813 | // enter the packet into our input stream |
766 | r = *i; |
814 | r = *i; |
767 | |
815 | |
768 | // remove the oldest packet, look forward, as it's oldest first |
816 | // remove the oldest packet, look forward, as it's oldest first |
769 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
817 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
770 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
818 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
771 | { |
819 | { |
|
|
820 | //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D |
772 | delete *j; |
821 | delete *j; |
773 | rcvpq.erase (j); |
822 | rcvpq.erase (j); |
774 | break; |
823 | break; |
775 | } |
824 | } |
776 | |
825 | |
777 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
826 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
778 | |
827 | |
779 | if (!rcvdq.put (r->data, r->datalen)) |
828 | if (!rcvdq.put (r->data, r->datalen)) |
780 | { |
829 | { |
|
|
830 | // MUST never overflow, can be caused by data corruption, TODO |
781 | slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); |
831 | slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)"); |
782 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
832 | c->dnsv4_reset_connection (); |
|
|
833 | return; |
783 | } |
834 | } |
784 | |
835 | |
785 | while (vpn_packet *pkt = rcvdq.get ()) |
836 | while (vpn_packet *pkt = rcvdq.get ()) |
786 | { |
837 | { |
787 | sockinfo si; |
838 | sockinfo si; |
788 | si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; |
839 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
789 | |
840 | |
790 | vpn->recv_vpn_packet (pkt, si); |
841 | vpn->recv_vpn_packet (pkt, si); |
791 | |
|
|
792 | delete pkt; |
842 | delete pkt; |
793 | } |
843 | } |
794 | |
844 | |
795 | // check for further packets |
845 | // check for further packets |
796 | goto redo; |
846 | goto redo; |
… | |
… | |
807 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
857 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
808 | |
858 | |
809 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
859 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
810 | && pkt.qdcount == htons (1)) |
860 | && pkt.qdcount == htons (1)) |
811 | { |
861 | { |
812 | char qname[MAXSIZE]; |
862 | char qname [MAXSIZE]; |
813 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
863 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
814 | |
864 | |
815 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
865 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
816 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
866 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
817 | |
867 | |
… | |
… | |
824 | |
874 | |
825 | int dlen = strlen (THISNODE->domain); |
875 | int dlen = strlen (THISNODE->domain); |
826 | |
876 | |
827 | if (qclass == RR_CLASS_IN |
877 | if (qclass == RR_CLASS_IN |
828 | && qlen > dlen + 1 |
878 | && qlen > dlen + 1 |
829 | && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) |
879 | && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen)) |
830 | { |
880 | { |
831 | // now generate reply |
881 | // now generate reply |
832 | pkt.ancount = htons (1); // one answer RR |
882 | pkt.ancount = htons (1); // one answer RR |
833 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
883 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
834 | |
884 | |
… | |
… | |
847 | if (0 < client && client <= conns.size ()) |
897 | if (0 < client && client <= conns.size ()) |
848 | { |
898 | { |
849 | connection *c = conns [client - 1]; |
899 | connection *c = conns [client - 1]; |
850 | dns_connection *dns = c->dns; |
900 | dns_connection *dns = c->dns; |
851 | dns_rcv *rcv; |
901 | dns_rcv *rcv; |
852 | bool in_seq; |
|
|
853 | |
902 | |
854 | if (dns) |
903 | if (dns) |
855 | { |
904 | { |
856 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
905 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
857 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
906 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
… | |
… | |
868 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
917 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
869 | |
918 | |
870 | goto duplicate_request; |
919 | goto duplicate_request; |
871 | } |
920 | } |
872 | |
921 | |
873 | in_seq = dns->rcvseq == seqno; |
|
|
874 | |
|
|
875 | // new packet, queue |
922 | // new packet, queue |
876 | rcv = new dns_rcv (seqno, data, datalen); |
923 | rcv = new dns_rcv (seqno, data, datalen); |
877 | dns->receive_rep (rcv); |
924 | dns->receive_rep (rcv); |
878 | } |
925 | } |
879 | |
926 | |
|
|
927 | { |
880 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
928 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
881 | |
929 | |
882 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
930 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
883 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
931 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
884 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
932 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
885 | pkt [offs++] = 0; pkt [offs++] = 0; |
933 | pkt [offs++] = 0; pkt [offs++] = 0; |
886 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
934 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
887 | |
935 | |
888 | int rdlen_offs = offs += 2; |
936 | int rdlen_offs = offs += 2; |
889 | |
937 | |
|
|
938 | if (dns) |
|
|
939 | { |
890 | int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; |
940 | int dlen = ntohs (dns->cfg.max_size) - offs; |
|
|
941 | |
891 | // bind doesn't compress well, so reduce further by one label length |
942 | // bind doesn't compress well, so reduce further by one label length |
892 | dlen -= qlen; |
943 | dlen -= qlen; |
893 | |
944 | |
894 | if (dns) |
|
|
895 | { |
|
|
896 | // only put data into in-order sequence packets, if |
945 | // only put data into in-order sequence packets, if |
897 | // we receive out-of-order packets we generate empty |
946 | // we receive out-of-order packets we generate empty |
898 | // replies |
947 | // replies |
899 | while (dlen > 1 && !dns->snddq.empty () && in_seq) |
948 | //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D |
|
|
949 | if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW) |
900 | { |
950 | { |
|
|
951 | dns->repseq = seqno; |
|
|
952 | |
|
|
953 | while (dlen > 1 && !dns->snddq.empty ()) |
|
|
954 | { |
901 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
955 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
902 | |
956 | |
903 | if (txtlen > dns->snddq.size ()) |
957 | if (txtlen > dns->snddq.size ()) |
904 | txtlen = dns->snddq.size (); |
958 | txtlen = dns->snddq.size (); |
905 | |
959 | |
906 | pkt[offs++] = txtlen; |
960 | pkt[offs++] = txtlen; |
907 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
961 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
908 | offs += txtlen; |
962 | offs += txtlen; |
909 | dns->snddq.remove (txtlen); |
963 | dns->snddq.remove (txtlen); |
910 | |
964 | |
911 | dlen -= txtlen + 1; |
965 | dlen -= txtlen + 1; |
|
|
966 | } |
912 | } |
967 | } |
913 | |
968 | |
914 | // avoid empty TXT rdata |
969 | // avoid completely empty TXT rdata |
915 | if (offs == rdlen_offs) |
970 | if (offs == rdlen_offs) |
916 | pkt[offs++] = 0; |
971 | pkt[offs++] = 0; |
917 | |
972 | |
918 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
973 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
919 | } |
974 | } |
920 | else |
975 | else |
921 | { |
976 | { |
922 | // send RST |
977 | // send RST |
923 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
978 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
924 | pkt [offs++] = CMD_IP_RST; |
979 | pkt [offs++] = CMD_IP_RST; |
925 | } |
980 | } |
926 | |
981 | |
927 | int rdlen = offs - rdlen_offs; |
982 | int rdlen = offs - rdlen_offs; |
928 | |
983 | |
929 | pkt [rdlen_offs - 2] = rdlen >> 8; |
984 | pkt [rdlen_offs - 2] = rdlen >> 8; |
930 | pkt [rdlen_offs - 1] = rdlen; |
985 | pkt [rdlen_offs - 1] = rdlen; |
931 | |
986 | |
932 | if (dns) |
987 | if (dns) |
933 | { |
988 | { |
934 | // now update dns_rcv copy |
989 | // now update dns_rcv copy |
935 | rcv->pkt->len = offs; |
990 | rcv->pkt->len = offs; |
936 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
991 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
937 | } |
992 | } |
|
|
993 | } |
938 | |
994 | |
939 | duplicate_request: ; |
995 | duplicate_request: ; |
940 | } |
996 | } |
941 | else |
997 | else |
942 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
998 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
… | |
… | |
954 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
1010 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
955 | pkt [offs++] = 0; pkt [offs++] = 0; |
1011 | pkt [offs++] = 0; pkt [offs++] = 0; |
956 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
1012 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
957 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
1013 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
958 | |
1014 | |
959 | slog (L_INFO, _("DNS: client %d tries to connect"), client); |
1015 | slog (L_INFO, _("DNS: client %d connects"), client); |
960 | |
1016 | |
961 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
1017 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
962 | pkt [offs++] = CMD_IP_REJ; |
1018 | pkt [offs++] = CMD_IP_REJ; |
963 | |
1019 | |
964 | if (0 < client && client <= conns.size ()) |
1020 | if (0 < client && client <= conns.size ()) |
… | |
… | |
998 | { |
1054 | { |
999 | dns_connection *dns = (*i)->dns; |
1055 | dns_connection *dns = (*i)->dns; |
1000 | connection *c = dns->c; |
1056 | connection *c = dns->c; |
1001 | int seqno = (*i)->seqno; |
1057 | int seqno = (*i)->seqno; |
1002 | u8 data[MAXSIZE], *datap = data; |
1058 | u8 data[MAXSIZE], *datap = data; |
|
|
1059 | //printf ("rcv pkt %x\n", seqno);//D |
1003 | |
1060 | |
1004 | if ((*i)->retry) |
1061 | if ((*i)->retry) |
1005 | { |
1062 | { |
1006 | dns->send_interval *= 1.01; |
1063 | dns->send_interval *= 1.01; |
1007 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1064 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1008 | dns->send_interval = MAX_SEND_INTERVAL; |
1065 | dns->send_interval = MAX_SEND_INTERVAL; |
1009 | } |
1066 | } |
1010 | else |
1067 | else |
1011 | { |
1068 | { |
1012 | #if 1 |
1069 | #if 0 |
1013 | dns->send_interval *= 0.999; |
1070 | dns->send_interval *= 0.999; |
1014 | #endif |
1071 | #endif |
1015 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
1016 | dns->send_interval = MIN_SEND_INTERVAL; |
|
|
1017 | |
|
|
1018 | // the latency surely puts an upper bound on |
1072 | // the latency surely puts an upper bound on |
1019 | // the minimum send interval |
1073 | // the minimum send interval |
1020 | double latency = NOW - (*i)->sent; |
1074 | double latency = ev_now () - (*i)->sent; |
|
|
1075 | |
|
|
1076 | if (latency < dns->min_latency) |
1021 | dns->last_latency = latency; |
1077 | dns->min_latency = latency; |
1022 | |
1078 | |
1023 | if (dns->send_interval > latency) |
1079 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
|
|
1080 | dns->send_interval = dns->min_latency * conf.dns_overlap_factor; |
|
|
1081 | |
|
|
1082 | if (dns->send_interval < conf.dns_send_interval) |
1024 | dns->send_interval = latency; |
1083 | dns->send_interval = conf.dns_send_interval; |
1025 | } |
1084 | } |
1026 | |
1085 | |
1027 | delete *i; |
1086 | delete *i; |
1028 | dns_sndpq.erase (i); |
1087 | dns_sndpq.erase (i); |
1029 | |
1088 | |
… | |
… | |
1085 | |
1144 | |
1086 | if (ip [3] == CMD_IP_RST) |
1145 | if (ip [3] == CMD_IP_RST) |
1087 | { |
1146 | { |
1088 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1147 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1089 | |
1148 | |
1090 | delete dns; c->dns = 0; |
1149 | c->dnsv4_reset_connection (); |
1091 | |
|
|
1092 | return; |
|
|
1093 | } |
1150 | } |
1094 | else if (ip [3] == CMD_IP_SYN) |
1151 | else if (ip [3] == CMD_IP_SYN) |
1095 | { |
1152 | { |
1096 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1153 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1097 | dns->established = true; |
1154 | dns->established = true; |
1098 | } |
1155 | } |
1099 | else if (ip [3] == CMD_IP_REJ) |
1156 | else if (ip [3] == CMD_IP_REJ) |
1100 | { |
|
|
1101 | slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); |
1157 | slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us.")); |
1102 | abort (); |
|
|
1103 | } |
|
|
1104 | else |
1158 | else |
1105 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1159 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1106 | } |
1160 | } |
1107 | else |
1161 | else |
1108 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1162 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
… | |
… | |
1134 | break; |
1188 | break; |
1135 | } |
1189 | } |
1136 | } |
1190 | } |
1137 | |
1191 | |
1138 | void |
1192 | void |
1139 | vpn::dnsv4_ev (io_watcher &w, short revents) |
1193 | vpn::dnsv4_ev (ev::io &w, int revents) |
1140 | { |
1194 | { |
1141 | if (revents & EVENT_READ) |
1195 | if (revents & EV_READ) |
1142 | { |
1196 | { |
1143 | dns_packet *pkt = new dns_packet; |
1197 | dns_packet *pkt = new dns_packet; |
1144 | struct sockaddr_in sa; |
1198 | struct sockaddr_in sa; |
1145 | socklen_t sa_len = sizeof (sa); |
1199 | socklen_t sa_len = sizeof (sa); |
1146 | |
1200 | |
1147 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1201 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1148 | |
1202 | |
1149 | if (pkt->len > 0) |
1203 | if (pkt->len > 0) |
1150 | { |
1204 | { |
1151 | if (THISNODE->dns_port) |
1205 | if (ntohs (pkt->flags) & FLAG_RESPONSE) |
|
|
1206 | dnsv4_client (*pkt); |
|
|
1207 | else |
1152 | { |
1208 | { |
1153 | dnsv4_server (*pkt); |
1209 | dnsv4_server (*pkt); |
1154 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1210 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1155 | } |
1211 | } |
1156 | else |
|
|
1157 | dnsv4_client (*pkt); |
|
|
1158 | |
1212 | |
1159 | delete pkt; |
1213 | delete pkt; |
1160 | } |
1214 | } |
1161 | } |
1215 | } |
1162 | } |
1216 | } |
1163 | |
1217 | |
1164 | bool |
1218 | bool |
1165 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1219 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1166 | { |
1220 | { |
1167 | int client = ntohs (si.port); |
1221 | int client = ntohl (si.host); |
1168 | |
1222 | |
1169 | assert (0 < client && client <= conns.size ()); |
1223 | assert (0 < client && client <= conns.size ()); |
1170 | |
1224 | |
1171 | connection *c = conns [client - 1]; |
1225 | connection *c = conns [client - 1]; |
1172 | |
1226 | |
1173 | if (!c->dns) |
1227 | if (!c->dns) |
1174 | c->dns = new dns_connection (c); |
1228 | c->dns = new dns_connection (c); |
1175 | |
1229 | |
1176 | if (!c->dns->snddq.put (pkt)) |
1230 | if (c->dns->snddq.put (pkt)) |
1177 | return false; |
|
|
1178 | |
|
|
1179 | c->dns->tw.trigger (); |
1231 | c->dns->tw (); |
1180 | |
1232 | |
|
|
1233 | // always return true even if the buffer overflows |
1181 | return true; |
1234 | return true; |
1182 | } |
1235 | } |
1183 | |
1236 | |
1184 | void |
1237 | void |
1185 | connection::dnsv4_reset_connection () |
1238 | connection::dnsv4_reset_connection () |
… | |
… | |
1188 | } |
1241 | } |
1189 | |
1242 | |
1190 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
1243 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
1191 | |
1244 | |
1192 | void |
1245 | void |
1193 | dns_connection::time_cb (time_watcher &w) |
1246 | dns_connection::time_cb (ev::timer &w, int revents) |
1194 | { |
1247 | { |
1195 | // servers have to be polled |
1248 | // servers have to be polled |
1196 | if (THISNODE->dns_port) |
1249 | if (THISNODE->dns_port) |
1197 | return; |
1250 | return; |
1198 | |
1251 | |
1199 | // check for timeouts and (re)transmit |
1252 | // check for timeouts and (re)transmit |
1200 | tstamp next = NOW + poll_interval; |
1253 | tstamp next = ev::now () + poll_interval; |
1201 | dns_snd *send = 0; |
1254 | dns_snd *send = 0; |
1202 | |
1255 | |
1203 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1256 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1204 | i != vpn->dns_sndpq.end (); |
1257 | i != vpn->dns_sndpq.end (); |
1205 | ++i) |
1258 | ++i) |
1206 | { |
1259 | { |
1207 | dns_snd *r = *i; |
1260 | dns_snd *r = *i; |
1208 | |
1261 | |
1209 | if (r->timeout <= NOW) |
1262 | if (r->timeout <= ev_now ()) |
1210 | { |
1263 | { |
1211 | if (!send) |
1264 | if (!send) |
1212 | { |
1265 | { |
1213 | send = r; |
1266 | send = r; |
1214 | |
1267 | |
1215 | r->retry++; |
1268 | r->retry++; |
1216 | r->timeout = NOW + (r->retry * last_latency * 8.); |
1269 | r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); |
|
|
1270 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
1217 | |
1271 | |
1218 | // the following code changes the query section a bit, forcing |
1272 | // the following code changes the query section a bit, forcing |
1219 | // the forwarder to generate a new request |
1273 | // the forwarder to generate a new request |
1220 | if (r->stdhdr) |
1274 | if (r->stdhdr) |
1221 | { |
|
|
1222 | //printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
|
|
1223 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1275 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1224 | } |
|
|
1225 | } |
1276 | } |
1226 | } |
1277 | } |
1227 | else |
1278 | else |
1228 | NEXT (r->timeout); |
1279 | NEXT (r->timeout); |
1229 | } |
1280 | } |
1230 | |
1281 | |
1231 | if (last_sent + send_interval <= NOW) |
|
|
1232 | { |
|
|
1233 | if (!send) |
1282 | if (!send) |
|
|
1283 | { |
|
|
1284 | // generate a new packet, if wise |
|
|
1285 | |
|
|
1286 | if (!established) |
1234 | { |
1287 | { |
1235 | // generate a new packet, if wise |
1288 | if (vpn->dns_sndpq.empty ()) |
1236 | |
|
|
1237 | if (!established) |
|
|
1238 | { |
1289 | { |
1239 | if (vpn->dns_sndpq.empty ()) |
|
|
1240 | { |
|
|
1241 | send = new dns_snd (this); |
1290 | send = new dns_snd (this); |
1242 | |
1291 | |
1243 | printf ("new conn %p %d\n", this, c->conf->id);//D |
|
|
1244 | cfg.reset (THISNODE->id); |
1292 | cfg.reset (THISNODE->id); |
1245 | send->gen_syn_req (); |
1293 | send->gen_syn_req (); |
1246 | } |
|
|
1247 | } |
1294 | } |
1248 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1295 | } |
|
|
1296 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1249 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1297 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
|
|
1298 | { |
|
|
1299 | if (last_sent + send_interval <= ev_now ()) |
1250 | { |
1300 | { |
1251 | //printf ("sending data request etc.\n"); //D |
1301 | //printf ("sending data request etc.\n"); //D |
1252 | if (!snddq.empty ()) |
1302 | if (!snddq.empty () || last_received + 1. > ev_now ()) |
1253 | { |
1303 | { |
1254 | poll_interval = send_interval; |
1304 | poll_interval = send_interval; |
1255 | NEXT (NOW + send_interval); |
1305 | NEXT (ev_now () + send_interval); |
1256 | } |
1306 | } |
1257 | |
1307 | |
1258 | send = new dns_snd (this); |
1308 | send = new dns_snd (this); |
1259 | send->gen_stream_req (sndseq, snddq); |
1309 | send->gen_stream_req (sndseq, snddq); |
1260 | send->timeout = NOW + last_latency * 8.; |
1310 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
|
|
1311 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
1261 | |
1312 | |
1262 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1313 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1263 | } |
1314 | } |
1264 | |
1315 | else |
1265 | if (send) |
1316 | NEXT (last_sent + send_interval); |
1266 | vpn->dns_sndpq.push_back (send); |
|
|
1267 | } |
1317 | } |
1268 | |
1318 | |
1269 | if (send) |
1319 | if (send) |
1270 | { |
1320 | vpn->dns_sndpq.push_back (send); |
1271 | last_sent = NOW; |
1321 | } |
|
|
1322 | |
|
|
1323 | if (send) |
|
|
1324 | { |
|
|
1325 | last_sent = ev_now (); |
1272 | sendto (vpn->dnsv4_fd, |
1326 | sendto (vpn->dnsv4_fd, |
1273 | send->pkt->at (0), send->pkt->len, 0, |
1327 | send->pkt->at (0), send->pkt->len, 0, |
1274 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1328 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1275 | } |
|
|
1276 | } |
1329 | } |
1277 | else |
|
|
1278 | NEXT (last_sent + send_interval); |
|
|
1279 | |
1330 | |
1280 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", |
1331 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1281 | poll_interval, send_interval, next - NOW, |
1332 | poll_interval, send_interval, next - ev_now (), |
1282 | vpn->dns_sndpq.size (), snddq.size ()); |
1333 | vpn->dns_sndpq.size (), snddq.size (), |
|
|
1334 | rcvpq.size ()); |
1283 | |
1335 | |
1284 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1336 | // TODO: no idea when this happens, but when next < ev_now (), we have a problem |
|
|
1337 | // doesn't seem to happen anymore |
1285 | if (next < NOW + 0.0001) |
1338 | if (next < ev_now () + 0.001) |
1286 | next = NOW + 0.1; |
1339 | next = ev_now () + 0.1; |
1287 | |
1340 | |
1288 | w.start (next); |
1341 | w.start (next - ev_now ()); |
1289 | } |
1342 | } |
1290 | |
1343 | |
1291 | #endif |
1344 | #endif |
1292 | |
1345 | |