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) 2003-2011 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. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 | */ |
21 | |
31 | |
22 | // TODO: EDNS0 option to increase dns mtu? |
32 | // TODO: EDNS0 option to increase dns mtu? |
23 | // TODO: re-write dns packet parsing/creation using a safe mem-buffer |
33 | // TODO: re-write dns packet parsing/creation using a safe mem-buffer |
24 | // to ensure no buffer overflows or similar problems. |
34 | // to ensure no buffer overflows or similar problems. |
… | |
… | |
42 | #include <unistd.h> |
52 | #include <unistd.h> |
43 | #include <fcntl.h> |
53 | #include <fcntl.h> |
44 | |
54 | |
45 | #include <map> |
55 | #include <map> |
46 | |
56 | |
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57 | #include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */ |
47 | #include <gmp.h> |
58 | #include <gmp.h> |
48 | |
59 | |
49 | #include "netcompat.h" |
60 | #include "netcompat.h" |
50 | |
61 | |
51 | #include "vpn.h" |
62 | #include "vpn.h" |
52 | |
63 | |
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64 | #define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received |
53 | #define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data |
65 | #define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data |
54 | #define ACTIVITY_INTERVAL 5. |
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55 | |
66 | |
56 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
67 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
57 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
68 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
58 | |
69 | |
59 | #define MAX_SEND_INTERVAL 2. // optimistic? |
70 | #define MAX_SEND_INTERVAL 5. // optimistic? |
60 | |
71 | |
61 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
72 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
62 | #define MAX_BACKLOG (64*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 |
63 | |
74 | |
64 | #define MAX_DOMAIN_SIZE 240 // 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 |
… | |
… | |
72 | #define MAX_PKT_SIZE 512 |
83 | #define MAX_PKT_SIZE 512 |
73 | |
84 | |
74 | #define RR_TYPE_A 1 |
85 | #define RR_TYPE_A 1 |
75 | #define RR_TYPE_NULL 10 |
86 | #define RR_TYPE_NULL 10 |
76 | #define RR_TYPE_TXT 16 |
87 | #define RR_TYPE_TXT 16 |
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88 | #define RR_TYPE_AAAA 28 |
77 | #define RR_TYPE_ANY 255 |
89 | #define RR_TYPE_ANY 255 |
78 | |
90 | |
79 | #define RR_CLASS_IN 1 |
91 | #define RR_CLASS_IN 1 |
80 | |
92 | |
81 | #define CMD_IP_1 207 |
93 | #define CMD_IP_1 207 |
82 | #define CMD_IP_2 46 |
94 | #define CMD_IP_2 46 |
83 | #define CMD_IP_3 236 |
95 | #define CMD_IP_3 236 |
84 | #define CMD_IP_RST 29 |
96 | |
85 | #define CMD_IP_SYN 113 |
97 | #define CMD_IP_RST 29 // some error, reset and retry |
86 | #define CMD_IP_REJ 32 |
98 | #define CMD_IP_REJ 32 // do not want you |
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99 | #define CMD_IP_SYN 113 // connection established |
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100 | #define CMD_IP_CSE 213 // connection established, but likely case mismatch |
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101 | |
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102 | static bool |
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103 | is_uc (char c) |
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104 | { |
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105 | return 'A' <= c && c <= 'Z'; |
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106 | } |
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107 | |
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108 | static bool |
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109 | is_lc (char c) |
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110 | { |
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111 | return 'a' <= c && c <= 'z'; |
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112 | } |
87 | |
113 | |
88 | // works for cmaps up to 255 (not 256!) |
114 | // works for cmaps up to 255 (not 256!) |
89 | struct charmap |
115 | struct charmap |
90 | { |
116 | { |
91 | enum { INVALID = (u8)255 }; |
117 | enum { INVALID = (u8)255 }; |
… | |
… | |
105 | memset (enc, (char) 0, 256); |
131 | memset (enc, (char) 0, 256); |
106 | memset (dec, (char)INVALID, 256); |
132 | memset (dec, (char)INVALID, 256); |
107 | |
133 | |
108 | for (size = 0; cmap [size]; size++) |
134 | for (size = 0; cmap [size]; size++) |
109 | { |
135 | { |
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136 | char c = cmap [size]; |
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137 | |
110 | enc [size] = cmap [size]; |
138 | enc [size] = c; |
111 | dec [(u8)enc [size]] = size; |
139 | dec [(u8)c] = size; |
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140 | |
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141 | // allow lowercase/uppercase aliases if possible |
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142 | if (is_uc (c) && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size; |
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143 | if (is_lc (c) && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size; |
112 | } |
144 | } |
113 | |
145 | |
114 | assert (size < 256); |
146 | assert (size < 256); |
115 | } |
147 | } |
116 | |
148 | |
… | |
… | |
123 | { |
155 | { |
124 | charmap cmap; |
156 | charmap cmap; |
125 | unsigned int enc_len [MAX_DEC_LEN]; |
157 | unsigned int enc_len [MAX_DEC_LEN]; |
126 | unsigned int dec_len [MAX_ENC_LEN]; |
158 | unsigned int dec_len [MAX_ENC_LEN]; |
127 | |
159 | |
128 | unsigned int encode_len (unsigned int len); |
160 | unsigned int encode_len (unsigned int len) const; |
129 | unsigned int decode_len (unsigned int len); |
161 | unsigned int decode_len (unsigned int len) const; |
130 | |
162 | |
131 | unsigned int encode (char *dst, u8 *src, unsigned int len); |
163 | unsigned int encode (char *dst, u8 *src, unsigned int len) const; |
132 | unsigned int decode (u8 *dst, char *src, unsigned int len); |
164 | unsigned int decode (u8 *dst, char *src, unsigned int len) const; |
133 | |
165 | |
134 | basecoder (const char *cmap); |
166 | basecoder (const char *cmap); |
135 | }; |
167 | }; |
136 | |
168 | |
137 | basecoder::basecoder (const char *cmap) |
169 | basecoder::basecoder (const char *cmap) |
… | |
… | |
156 | enc_len [len] = n; |
188 | enc_len [len] = n; |
157 | dec_len [n] = len; |
189 | dec_len [n] = len; |
158 | } |
190 | } |
159 | } |
191 | } |
160 | |
192 | |
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193 | unsigned int |
161 | unsigned int basecoder::encode_len (unsigned int len) |
194 | basecoder::encode_len (unsigned int len) const |
162 | { |
195 | { |
163 | return enc_len [len]; |
196 | return enc_len [len]; |
164 | } |
197 | } |
165 | |
198 | |
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199 | unsigned int |
166 | unsigned int basecoder::decode_len (unsigned int len) |
200 | basecoder::decode_len (unsigned int len) const |
167 | { |
201 | { |
168 | while (len && !dec_len [len]) |
202 | while (len && !dec_len [len]) |
169 | --len; |
203 | --len; |
170 | |
204 | |
171 | return dec_len [len]; |
205 | return dec_len [len]; |
172 | } |
206 | } |
173 | |
207 | |
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208 | unsigned int |
174 | unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) |
209 | basecoder::encode (char *dst, u8 *src, unsigned int len) const |
175 | { |
210 | { |
176 | if (!len || len > MAX_DEC_LEN) |
211 | if (!len || len > MAX_DEC_LEN) |
177 | return 0; |
212 | return 0; |
178 | |
213 | |
179 | int elen = encode_len (len); |
214 | int elen = encode_len (len); |
… | |
… | |
198 | *dst++ = cmap.encode [dst_ [i]]; |
233 | *dst++ = cmap.encode [dst_ [i]]; |
199 | |
234 | |
200 | return elen; |
235 | return elen; |
201 | } |
236 | } |
202 | |
237 | |
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238 | unsigned int |
203 | unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) |
239 | basecoder::decode (u8 *dst, char *src, unsigned int len) const |
204 | { |
240 | { |
205 | if (!len || len > MAX_ENC_LEN) |
241 | if (!len || len > MAX_ENC_LEN) |
206 | return 0; |
242 | return 0; |
207 | |
243 | |
208 | u8 src_ [MAX_ENC_LEN]; |
244 | u8 src_ [MAX_ENC_LEN]; |
… | |
… | |
257 | } |
293 | } |
258 | abort (); |
294 | abort (); |
259 | } |
295 | } |
260 | #endif |
296 | #endif |
261 | |
297 | |
262 | //static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-"); |
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263 | //static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); |
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264 | static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); |
298 | static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9 |
265 | //static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet |
299 | static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers |
266 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
300 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z |
267 | |
301 | |
268 | ///////////////////////////////////////////////////////////////////////////// |
302 | ///////////////////////////////////////////////////////////////////////////// |
269 | |
303 | |
270 | #define HDRSIZE 6 |
304 | #define HDRSIZE 5 |
271 | |
305 | |
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306 | inline void |
272 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
307 | encode_header (char *data, int clientid, int seqno, int retry = 0) |
273 | { |
308 | { |
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309 | assert (clientid < 256); |
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310 | |
274 | seqno &= SEQNO_MASK; |
311 | seqno &= SEQNO_MASK; |
275 | |
312 | |
276 | u8 hdr[3] = { |
313 | u8 hdr[3] = { |
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314 | seqno, |
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315 | (seqno >> 8) | (retry << 6), |
277 | clientid, |
316 | clientid, |
278 | (seqno >> 8) | (retry << 6), |
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279 | seqno, |
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280 | }; |
317 | }; |
281 | |
318 | |
282 | assert (clientid < 256); |
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283 | |
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284 | cdc26.encode (data, hdr, 3); |
319 | cdc36.encode (data, hdr, 3); |
285 | } |
320 | } |
286 | |
321 | |
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322 | inline void |
287 | inline void decode_header (char *data, int &clientid, int &seqno) |
323 | decode_header (char *data, int &clientid, int &seqno) |
288 | { |
324 | { |
289 | u8 hdr[3]; |
325 | u8 hdr[3]; |
290 | |
326 | |
291 | cdc26.decode (hdr, data, HDRSIZE); |
327 | cdc36.decode (hdr, data, HDRSIZE); |
292 | |
328 | |
293 | clientid = hdr[0]; |
329 | clientid = hdr[2]; |
294 | seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; |
330 | seqno = ((hdr[1] << 8) | hdr[0]) & SEQNO_MASK; |
295 | } |
331 | } |
296 | |
332 | |
297 | ///////////////////////////////////////////////////////////////////////////// |
333 | ///////////////////////////////////////////////////////////////////////////// |
298 | |
334 | |
299 | struct byte_stream |
335 | struct byte_stream |
… | |
… | |
325 | byte_stream::~byte_stream () |
361 | byte_stream::~byte_stream () |
326 | { |
362 | { |
327 | delete data; |
363 | delete data; |
328 | } |
364 | } |
329 | |
365 | |
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366 | void |
330 | void byte_stream::remove (int count) |
367 | byte_stream::remove (int count) |
331 | { |
368 | { |
332 | if (count > fill) |
369 | if (count > fill) |
333 | assert (count <= fill); |
370 | assert (count <= fill); |
334 | |
371 | |
335 | memmove (data, data + count, fill -= count); |
372 | memmove (data, data + count, fill -= count); |
336 | } |
373 | } |
337 | |
374 | |
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375 | bool |
338 | bool byte_stream::put (u8 *data, unsigned int datalen) |
376 | byte_stream::put (u8 *data, unsigned int datalen) |
339 | { |
377 | { |
340 | if (maxsize - fill < datalen) |
378 | if (maxsize - fill < datalen) |
341 | return false; |
379 | return false; |
342 | |
380 | |
343 | memcpy (this->data + fill, data, datalen); fill += datalen; |
381 | memcpy (this->data + fill, data, datalen); fill += datalen; |
344 | |
382 | |
345 | return true; |
383 | return true; |
346 | } |
384 | } |
347 | |
385 | |
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386 | bool |
348 | bool byte_stream::put (vpn_packet *pkt) |
387 | byte_stream::put (vpn_packet *pkt) |
349 | { |
388 | { |
350 | if (maxsize - fill < pkt->len + 2) |
389 | if (maxsize - fill < pkt->len + 2) |
351 | return false; |
390 | return false; |
352 | |
391 | |
353 | data [fill++] = pkt->len >> 8; |
392 | data [fill++] = pkt->len >> 8; |
… | |
… | |
409 | |
448 | |
410 | struct dns_cfg |
449 | struct dns_cfg |
411 | { |
450 | { |
412 | static int next_uid; |
451 | static int next_uid; |
413 | |
452 | |
414 | u8 id1, id2, id3, id4; |
453 | u8 chksum; |
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454 | u8 rrtype; |
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455 | u16 uid; // to make request unique |
415 | |
456 | |
416 | u8 version; |
457 | u8 version; |
417 | u8 flags; |
458 | u8 flags; |
418 | u8 rrtype; |
459 | u16 max_size; |
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460 | |
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461 | u8 id1, id2, id3, id4; |
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462 | |
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463 | u16 client; |
419 | u8 def_ttl; |
464 | u8 def_ttl; |
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465 | u8 r0; |
420 | |
466 | |
421 | u16 client; |
467 | u8 syn_cdc; // cdc en/decoder for syn (A?) requests |
422 | u16 uid; // to make request unique |
468 | u8 hdr_cdc; // cdc en/decoder for regular request headers |
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469 | u8 req_cdc; // cdc en/decoder for regular (ANY?) request data |
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470 | u8 rep_cdc; // cdc en/decoder for regular (TXT) replies, 0 == 8 bit encoding |
423 | |
471 | |
424 | u16 max_size; |
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425 | u8 seq_cdc; |
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426 | u8 req_cdc; |
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427 | |
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428 | u8 rep_cdc; |
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429 | u8 delay; // time in 0.01s units that the server may delay replying packets |
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430 | u8 r3, r4; |
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431 | |
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432 | u8 r5, r6, r7, r8; |
472 | u8 r1, r2, r3, r4; |
433 | |
473 | |
434 | void reset (int clientid); |
474 | void reset (int clientid); |
435 | bool valid (); |
475 | bool valid (); |
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476 | u8 get_chksum (); |
436 | }; |
477 | }; |
437 | |
478 | |
438 | int dns_cfg::next_uid; |
479 | int dns_cfg::next_uid; |
439 | |
480 | |
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481 | void |
440 | void dns_cfg::reset (int clientid) |
482 | dns_cfg::reset (int clientid) |
441 | { |
483 | { |
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484 | // this ID must result in some mixed-case characters in cdc26-encoding |
442 | id1 = 'G'; |
485 | id1 = 'G'; |
443 | id2 = 'V'; |
486 | id2 = 'V'; |
444 | id3 = 'P'; |
487 | id3 = 'P'; |
445 | id4 = 'E'; |
488 | id4 = 'E'; |
446 | |
489 | |
447 | version = 1; |
490 | version = 2; |
448 | |
491 | |
449 | rrtype = RR_TYPE_TXT; |
492 | rrtype = RR_TYPE_TXT; |
450 | flags = 0; |
493 | flags = 0; |
451 | def_ttl = 0; |
494 | def_ttl = 0; |
452 | seq_cdc = 26; |
495 | syn_cdc = 26; |
453 | req_cdc = 62; |
496 | hdr_cdc = 36; |
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497 | req_cdc = conf.dns_case_preserving ? 62 : 36; |
454 | rep_cdc = 0; |
498 | rep_cdc = 0; |
455 | max_size = htons (MAX_PKT_SIZE); |
499 | max_size = htons (MAX_PKT_SIZE); |
456 | client = htons (clientid); |
500 | client = htons (clientid); |
457 | uid = next_uid++; |
501 | uid = ++next_uid; |
458 | delay = 0; |
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459 | |
502 | |
460 | r3 = r4 = 0; |
503 | r0 = r1 = r2 = r3 = r4 = 0; |
461 | r4 = r5 = r6 = r7 = 0; |
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462 | } |
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463 | |
504 | |
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505 | chksum = get_chksum (); |
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506 | } |
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507 | |
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508 | // simple but not trivial chksum |
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509 | u8 |
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510 | dns_cfg::get_chksum () |
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511 | { |
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512 | unsigned int sum = 0xff00; // only 16 bits required |
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513 | |
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514 | u8 old_chksum = chksum; |
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515 | chksum = 0; |
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516 | |
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517 | for (unsigned int i = 0; i < sizeof (*this); ++i) |
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518 | sum += ((u8 *)this)[i] * (i + 1); |
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519 | |
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520 | chksum = old_chksum; |
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521 | |
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522 | return sum + (sum >> 8); |
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523 | } |
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524 | |
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525 | bool |
464 | bool dns_cfg::valid () |
526 | dns_cfg::valid () |
465 | { |
527 | { |
466 | // although the protocol itself allows for some configurability, |
528 | // although the protocol itself allows for some configurability, |
467 | // only the following encoding/decoding settings are implemented. |
529 | // only the following encoding/decoding settings are implemented. |
468 | return id1 == 'G' |
530 | return id1 == 'G' |
469 | && id2 == 'V' |
531 | && id2 == 'V' |
470 | && id3 == 'P' |
532 | && id3 == 'P' |
471 | && id4 == 'E' |
533 | && id4 == 'E' |
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534 | && version == 2 |
472 | && seq_cdc == 26 |
535 | && syn_cdc == 26 |
473 | && req_cdc == 62 |
536 | && hdr_cdc == 36 |
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537 | && (req_cdc == 36 || req_cdc == 62) |
474 | && rep_cdc == 0 |
538 | && rep_cdc == 0 |
475 | && version == 1; |
539 | && chksum == get_chksum (); |
476 | } |
540 | } |
477 | |
541 | |
478 | struct dns_packet : net_packet |
542 | struct dns_packet : net_packet |
479 | { |
543 | { |
480 | u16 id; |
544 | u16 id; |
… | |
… | |
484 | u8 data [MAXSIZE - 6 * 2]; |
548 | u8 data [MAXSIZE - 6 * 2]; |
485 | |
549 | |
486 | int decode_label (char *data, int size, int &offs); |
550 | int decode_label (char *data, int size, int &offs); |
487 | }; |
551 | }; |
488 | |
552 | |
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553 | int |
489 | int dns_packet::decode_label (char *data, int size, int &offs) |
554 | dns_packet::decode_label (char *data, int size, int &offs) |
490 | { |
555 | { |
491 | char *orig = data; |
556 | char *orig = data; |
492 | |
557 | |
493 | memset (data, 0, size); |
558 | memset (data, 0, size); |
494 | |
559 | |
… | |
… | |
520 | return data - orig; |
585 | return data - orig; |
521 | } |
586 | } |
522 | |
587 | |
523 | ///////////////////////////////////////////////////////////////////////////// |
588 | ///////////////////////////////////////////////////////////////////////////// |
524 | |
589 | |
|
|
590 | static |
|
|
591 | u16 next_id () |
|
|
592 | { |
525 | static u16 dns_id = 0; // TODO: should be per-vpn |
593 | static u16 dns_id = 0; // TODO: should be per-vpn |
526 | |
594 | |
527 | static u16 next_id () |
|
|
528 | { |
|
|
529 | if (!dns_id) |
595 | if (!dns_id) |
530 | dns_id = time (0); |
596 | dns_id = time (0); |
531 | |
597 | |
532 | // the simplest lsfr with periodicity 65535 i could find |
598 | // the simplest lsfr with periodicity 65535 i could find |
533 | dns_id = (dns_id << 1) |
599 | dns_id = (dns_id << 1) |
… | |
… | |
548 | struct vpn *vpn; |
614 | struct vpn *vpn; |
549 | |
615 | |
550 | dns_cfg cfg; |
616 | dns_cfg cfg; |
551 | |
617 | |
552 | bool established; |
618 | bool established; |
|
|
619 | const basecoder *cdc; |
553 | |
620 | |
554 | tstamp last_received; |
621 | tstamp last_received; |
555 | tstamp last_sent; |
622 | tstamp last_sent; |
556 | double min_latency; |
623 | double min_latency; |
557 | double poll_interval, send_interval; |
624 | double poll_interval, send_interval; |
… | |
… | |
559 | vector<dns_rcv *> rcvpq; |
626 | vector<dns_rcv *> rcvpq; |
560 | |
627 | |
561 | byte_stream rcvdq; int rcvseq; int repseq; |
628 | byte_stream rcvdq; int rcvseq; int repseq; |
562 | byte_stream snddq; int sndseq; |
629 | byte_stream snddq; int sndseq; |
563 | |
630 | |
564 | void time_cb (ev::timer &w, int revents); ev::timer tw; |
631 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
565 | void receive_rep (dns_rcv *r); |
632 | void receive_rep (dns_rcv *r); |
|
|
633 | |
|
|
634 | void reset (); // quite like tcp RST |
|
|
635 | void set_cfg (); // to be called after any cfg changes |
566 | |
636 | |
567 | dns_connection (connection *c); |
637 | dns_connection (connection *c); |
568 | ~dns_connection (); |
638 | ~dns_connection (); |
569 | }; |
639 | }; |
570 | |
640 | |
… | |
… | |
588 | : dns (dns) |
658 | : dns (dns) |
589 | { |
659 | { |
590 | timeout = 0; |
660 | timeout = 0; |
591 | retry = 0; |
661 | retry = 0; |
592 | seqno = 0; |
662 | seqno = 0; |
593 | sent = ev::ev_now (); |
663 | sent = ev_now (); |
594 | stdhdr = false; |
664 | stdhdr = false; |
595 | |
665 | |
596 | pkt = new dns_packet; |
666 | pkt = new dns_packet; |
597 | |
667 | |
598 | pkt->id = next_id (); |
668 | pkt->id = next_id (); |
… | |
… | |
601 | dns_snd::~dns_snd () |
671 | dns_snd::~dns_snd () |
602 | { |
672 | { |
603 | delete pkt; |
673 | delete pkt; |
604 | } |
674 | } |
605 | |
675 | |
|
|
676 | static void |
606 | static void append_domain (dns_packet &pkt, int &offs, const char *domain) |
677 | append_domain (dns_packet &pkt, int &offs, const char *domain) |
607 | { |
678 | { |
608 | // add tunnel domain |
679 | // add tunnel domain |
609 | for (;;) |
680 | for (;;) |
610 | { |
681 | { |
611 | const char *end = strchr (domain, '.'); |
682 | const char *end = strchr (domain, '.'); |
… | |
… | |
624 | |
695 | |
625 | domain = end + 1; |
696 | domain = end + 1; |
626 | } |
697 | } |
627 | } |
698 | } |
628 | |
699 | |
|
|
700 | void |
629 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
701 | dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
630 | { |
702 | { |
631 | stdhdr = true; |
703 | stdhdr = true; |
632 | this->seqno = seqno; |
704 | this->seqno = seqno; |
633 | |
705 | |
634 | timeout = ev::ev_now () + INITIAL_TIMEOUT; |
706 | timeout = ev_now () + INITIAL_TIMEOUT; |
635 | |
707 | |
636 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
708 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
637 | pkt->qdcount = htons (1); |
709 | pkt->qdcount = htons (1); |
638 | |
710 | |
639 | int offs = 6*2; |
711 | int offs = 6*2; |
… | |
… | |
642 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
714 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
643 | |
715 | |
644 | char enc[256], *encp = enc; |
716 | char enc[256], *encp = enc; |
645 | encode_header (enc, THISNODE->id, seqno); |
717 | encode_header (enc, THISNODE->id, seqno); |
646 | |
718 | |
647 | int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); |
719 | int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); |
648 | |
720 | |
649 | if (datalen > stream.size ()) |
721 | if (datalen > stream.size ()) |
650 | datalen = stream.size (); |
722 | datalen = stream.size (); |
651 | |
723 | |
652 | int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
724 | int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
653 | stream.remove (datalen); |
725 | stream.remove (datalen); |
654 | |
726 | |
655 | while (enclen) |
727 | while (enclen) |
656 | { |
728 | { |
657 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
729 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
… | |
… | |
672 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
744 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
673 | |
745 | |
674 | pkt->len = offs; |
746 | pkt->len = offs; |
675 | } |
747 | } |
676 | |
748 | |
|
|
749 | void |
677 | void dns_snd::gen_syn_req () |
750 | dns_snd::gen_syn_req () |
678 | { |
751 | { |
679 | timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT; |
752 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
680 | |
753 | |
681 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
754 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
682 | pkt->qdcount = htons (1); |
755 | pkt->qdcount = htons (1); |
683 | |
756 | |
684 | int offs = 6 * 2; |
757 | int offs = 6 * 2; |
… | |
… | |
724 | |
797 | |
725 | dns_connection::dns_connection (connection *c) |
798 | dns_connection::dns_connection (connection *c) |
726 | : c (c) |
799 | : c (c) |
727 | , rcvdq (MAX_BACKLOG * 2) |
800 | , rcvdq (MAX_BACKLOG * 2) |
728 | , snddq (MAX_BACKLOG) |
801 | , snddq (MAX_BACKLOG) |
729 | , tw (this, &dns_connection::time_cb) |
|
|
730 | { |
802 | { |
|
|
803 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
|
|
804 | |
731 | vpn = c->vpn; |
805 | vpn = c->vpn; |
732 | |
806 | |
|
|
807 | reset (); |
|
|
808 | } |
|
|
809 | |
|
|
810 | dns_connection::~dns_connection () |
|
|
811 | { |
|
|
812 | reset (); |
|
|
813 | } |
|
|
814 | |
|
|
815 | void |
|
|
816 | dns_connection::reset () |
|
|
817 | { |
|
|
818 | while (!rcvpq.empty ()) |
|
|
819 | { |
|
|
820 | delete rcvpq.back (); |
|
|
821 | rcvpq.pop_back (); |
|
|
822 | } |
|
|
823 | |
|
|
824 | for (int i = vpn->dns_sndpq.size (); i--; ) |
|
|
825 | if (vpn->dns_sndpq [i]->dns == this) |
|
|
826 | { |
|
|
827 | vpn->dns_sndpq [i] = vpn->dns_sndpq.back (); |
|
|
828 | vpn->dns_sndpq.pop_back (); |
|
|
829 | } |
|
|
830 | |
733 | established = false; |
831 | established = false; |
734 | |
832 | |
735 | rcvseq = repseq = sndseq = 0; |
833 | rcvseq = repseq = sndseq = 0; |
736 | |
834 | |
737 | last_sent = last_received = 0; |
835 | last_sent = 0; |
738 | poll_interval = 0.5; // starting here |
836 | poll_interval = 0.5; // starting here |
739 | send_interval = 0.5; // starting rate |
837 | send_interval = 0.5; // starting rate |
740 | min_latency = INITIAL_TIMEOUT; |
838 | min_latency = INITIAL_TIMEOUT; |
741 | } |
839 | } |
742 | |
840 | |
743 | dns_connection::~dns_connection () |
841 | void |
|
|
842 | dns_connection::set_cfg () |
744 | { |
843 | { |
745 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
844 | cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62; |
746 | i != rcvpq.end (); |
|
|
747 | ++i) |
|
|
748 | delete *i; |
|
|
749 | } |
845 | } |
750 | |
846 | |
|
|
847 | void |
751 | void dns_connection::receive_rep (dns_rcv *r) |
848 | dns_connection::receive_rep (dns_rcv *r) |
752 | { |
849 | { |
753 | if (r->datalen) |
850 | if (r->datalen) |
754 | { |
851 | poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL); |
755 | last_received = ev::ev_now (); |
|
|
756 | tw (); |
|
|
757 | |
|
|
758 | poll_interval = send_interval; |
|
|
759 | } |
|
|
760 | else |
852 | else |
761 | { |
853 | poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL); |
762 | poll_interval *= 1.5; |
|
|
763 | |
|
|
764 | if (poll_interval > MAX_POLL_INTERVAL) |
|
|
765 | poll_interval = MAX_POLL_INTERVAL; |
|
|
766 | } |
|
|
767 | |
854 | |
768 | rcvpq.push_back (r); |
855 | rcvpq.push_back (r); |
769 | |
856 | |
770 | redo: |
857 | redo: |
771 | |
858 | |
… | |
… | |
789 | |
876 | |
790 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
877 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
791 | |
878 | |
792 | if (!rcvdq.put (r->data, r->datalen)) |
879 | if (!rcvdq.put (r->data, r->datalen)) |
793 | { |
880 | { |
|
|
881 | // MUST never overflow, can be caused by data corruption, TODO |
794 | slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); |
882 | slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)"); |
795 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
883 | reset (); |
|
|
884 | return; |
796 | } |
885 | } |
797 | |
886 | |
798 | while (vpn_packet *pkt = rcvdq.get ()) |
887 | while (vpn_packet *pkt = rcvdq.get ()) |
799 | { |
888 | { |
800 | sockinfo si; |
889 | sockinfo si; |
801 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
890 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
802 | |
891 | |
803 | vpn->recv_vpn_packet (pkt, si); |
892 | vpn->recv_vpn_packet (pkt, si); |
804 | |
|
|
805 | delete pkt; |
893 | delete pkt; |
806 | } |
894 | } |
807 | |
895 | |
808 | // check for further packets |
896 | // check for further packets |
809 | goto redo; |
897 | goto redo; |
… | |
… | |
852 | { |
940 | { |
853 | // correct class, domain: parse |
941 | // correct class, domain: parse |
854 | int client, seqno; |
942 | int client, seqno; |
855 | decode_header (qname, client, seqno); |
943 | decode_header (qname, client, seqno); |
856 | |
944 | |
857 | u8 data[MAXSIZE]; |
|
|
858 | int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
859 | |
|
|
860 | if (0 < client && client <= conns.size ()) |
945 | if (0 < client && client <= conns.size ()) |
861 | { |
946 | { |
862 | connection *c = conns [client - 1]; |
947 | connection *c = conns [client - 1]; |
863 | dns_connection *dns = c->dns; |
948 | dns_connection *dns = c->dns; |
864 | dns_rcv *rcv; |
949 | dns_rcv *rcv; |
865 | |
950 | |
866 | if (dns) |
951 | if (dns) |
867 | { |
952 | { |
|
|
953 | u8 data[MAXSIZE]; |
|
|
954 | int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
955 | |
868 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
956 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
869 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
957 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
870 | { |
958 | { |
871 | // already seen that request: simply reply with the cached reply |
959 | // already seen that request: simply reply with the cached reply |
872 | dns_rcv *r = *i; |
960 | dns_rcv *r = *i; |
… | |
… | |
973 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
1061 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
974 | pkt [offs++] = 0; pkt [offs++] = 0; |
1062 | pkt [offs++] = 0; pkt [offs++] = 0; |
975 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
1063 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
976 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
1064 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
977 | |
1065 | |
978 | slog (L_INFO, _("DNS: client %d connects"), client); |
|
|
979 | |
|
|
980 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
1066 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
981 | pkt [offs++] = CMD_IP_REJ; |
1067 | pkt [offs++] = CMD_IP_REJ; |
982 | |
1068 | |
983 | if (0 < client && client <= conns.size ()) |
1069 | if (0 < client && client <= conns.size ()) |
984 | { |
1070 | { |
985 | connection *c = conns [client - 1]; |
1071 | connection *c = conns [client - 1]; |
986 | |
1072 | |
987 | if (cfg.valid ()) |
1073 | if (cfg.valid ()) |
988 | { |
1074 | { |
989 | pkt [offs - 1] = CMD_IP_SYN; |
1075 | slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc); |
|
|
1076 | |
|
|
1077 | // check for any encoding mismatches - hints at a case problem |
|
|
1078 | char qname2 [MAX_ENC_LEN]; |
|
|
1079 | cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg)); |
990 | |
1080 | |
991 | delete c->dns; |
1081 | delete c->dns; |
|
|
1082 | |
|
|
1083 | pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg))) |
|
|
1084 | ? CMD_IP_CSE : CMD_IP_SYN; |
|
|
1085 | |
992 | c->dns = new dns_connection (c); |
1086 | c->dns = new dns_connection (c); |
993 | c->dns->cfg = cfg; |
1087 | c->dns->cfg = cfg; |
|
|
1088 | c->dns->set_cfg (); |
994 | } |
1089 | } |
995 | } |
1090 | } |
996 | } |
1091 | } |
997 | } |
1092 | } |
998 | |
1093 | |
… | |
… | |
1032 | #if 0 |
1127 | #if 0 |
1033 | dns->send_interval *= 0.999; |
1128 | dns->send_interval *= 0.999; |
1034 | #endif |
1129 | #endif |
1035 | // the latency surely puts an upper bound on |
1130 | // the latency surely puts an upper bound on |
1036 | // the minimum send interval |
1131 | // the minimum send interval |
1037 | double latency = ev::ev_now () - (*i)->sent; |
1132 | double latency = ev_now () - (*i)->sent; |
1038 | |
1133 | |
1039 | if (latency < dns->min_latency) |
1134 | if (latency < dns->min_latency) |
1040 | dns->min_latency = latency; |
1135 | dns->min_latency = latency; |
1041 | |
1136 | |
1042 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
1137 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
… | |
… | |
1069 | ttl |= pkt [offs++] << 16; |
1164 | ttl |= pkt [offs++] << 16; |
1070 | ttl |= pkt [offs++] << 8; |
1165 | ttl |= pkt [offs++] << 8; |
1071 | ttl |= pkt [offs++]; |
1166 | ttl |= pkt [offs++]; |
1072 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1167 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1073 | |
1168 | |
1074 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) |
1169 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype) |
1075 | { |
1170 | { |
1076 | if (rdlen <= MAXSIZE - offs) |
1171 | if (rdlen <= MAXSIZE - offs) |
1077 | { |
1172 | { |
1078 | // decode bytes, finally |
1173 | // decode bytes, finally |
1079 | |
1174 | |
… | |
… | |
1105 | { |
1200 | { |
1106 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1201 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1107 | |
1202 | |
1108 | if (ip [3] == CMD_IP_RST) |
1203 | if (ip [3] == CMD_IP_RST) |
1109 | { |
1204 | { |
1110 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1205 | slog (L_DEBUG, _("DNS: got tunnel RST request.")); |
1111 | |
1206 | |
1112 | delete dns; c->dns = 0; |
1207 | dns->reset (); |
1113 | |
|
|
1114 | return; |
1208 | return; |
1115 | } |
1209 | } |
1116 | else if (ip [3] == CMD_IP_SYN) |
1210 | else if (ip [3] == CMD_IP_SYN) |
1117 | { |
1211 | { |
1118 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1212 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1119 | dns->established = true; |
1213 | dns->established = true; |
1120 | } |
1214 | } |
|
|
1215 | else if (ip [3] == CMD_IP_CSE) |
|
|
1216 | { |
|
|
1217 | if (conf.dns_case_preserving) |
|
|
1218 | { |
|
|
1219 | slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol.")); |
|
|
1220 | conf.dns_case_preserving = false; |
|
|
1221 | dns->reset (); |
|
|
1222 | return; |
|
|
1223 | } |
|
|
1224 | else |
|
|
1225 | { |
|
|
1226 | slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us.")); |
|
|
1227 | dns->established = true; |
|
|
1228 | } |
|
|
1229 | } |
1121 | else if (ip [3] == CMD_IP_REJ) |
1230 | else if (ip [3] == CMD_IP_REJ) |
1122 | { |
1231 | { |
1123 | slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); |
1232 | slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us.")); |
1124 | abort (); |
1233 | dns->tw.start (60.); |
1125 | } |
1234 | } |
1126 | else |
1235 | else |
|
|
1236 | { |
1127 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1237 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
|
|
1238 | dns->tw.start (60.); |
|
|
1239 | } |
1128 | } |
1240 | } |
1129 | else |
1241 | else |
1130 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1242 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1131 | ip [0], ip [1], ip [2], ip [3]); |
1243 | ip [0], ip [1], ip [2], ip [3]); |
1132 | |
1244 | |
… | |
… | |
1194 | |
1306 | |
1195 | if (!c->dns) |
1307 | if (!c->dns) |
1196 | c->dns = new dns_connection (c); |
1308 | c->dns = new dns_connection (c); |
1197 | |
1309 | |
1198 | if (c->dns->snddq.put (pkt)) |
1310 | if (c->dns->snddq.put (pkt)) |
|
|
1311 | { |
|
|
1312 | min_it (c->dns->poll_interval, 0.25); |
1199 | c->dns->tw (); |
1313 | c->dns->tw (); |
|
|
1314 | } |
1200 | |
1315 | |
1201 | // always return true even if the buffer overflows |
1316 | // always return true even if the buffer overflows |
1202 | return true; |
1317 | return true; |
1203 | } |
1318 | } |
1204 | |
|
|
1205 | void |
|
|
1206 | connection::dnsv4_reset_connection () |
|
|
1207 | { |
|
|
1208 | //delete dns; dns = 0; //TODO |
|
|
1209 | } |
|
|
1210 | |
|
|
1211 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
|
|
1212 | |
1319 | |
1213 | void |
1320 | void |
1214 | dns_connection::time_cb (ev::timer &w, int revents) |
1321 | dns_connection::time_cb (ev::timer &w, int revents) |
1215 | { |
1322 | { |
1216 | // servers have to be polled |
1323 | // servers have to be polled |
1217 | if (THISNODE->dns_port) |
1324 | if (THISNODE->dns_port) |
1218 | return; |
1325 | return; |
1219 | |
1326 | |
1220 | // check for timeouts and (re)transmit |
1327 | // check for timeouts and (re)transmit |
1221 | tstamp next = ev::now () + poll_interval; |
1328 | tstamp next = 86400 * 365; |
1222 | dns_snd *send = 0; |
1329 | dns_snd *send = 0; |
1223 | |
1330 | |
1224 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1331 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1225 | i != vpn->dns_sndpq.end (); |
1332 | i != vpn->dns_sndpq.end (); |
1226 | ++i) |
1333 | ++i) |
1227 | { |
1334 | { |
1228 | dns_snd *r = *i; |
1335 | dns_snd *r = *i; |
1229 | |
1336 | |
1230 | if (r->timeout <= ev::ev_now ()) |
1337 | if (r->timeout <= ev_now ()) |
1231 | { |
1338 | { |
1232 | if (!send) |
1339 | if (!send) |
1233 | { |
1340 | { |
1234 | send = r; |
1341 | send = r; |
1235 | |
1342 | |
1236 | r->retry++; |
1343 | r->retry++; |
1237 | r->timeout = ev::ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); |
1344 | r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor; |
1238 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev::ev_now ());//D |
1345 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
1239 | |
1346 | |
1240 | // the following code changes the query section a bit, forcing |
1347 | // the following code changes the query section a bit, forcing |
1241 | // the forwarder to generate a new request |
1348 | // the forwarder to generate a new request |
1242 | if (r->stdhdr) |
1349 | if (r->stdhdr) |
1243 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1350 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1244 | } |
1351 | } |
1245 | } |
1352 | } |
1246 | else |
1353 | else |
1247 | NEXT (r->timeout); |
1354 | min_it (next, r->timeout - ev_now ()); |
1248 | } |
1355 | } |
1249 | |
1356 | |
1250 | if (!send) |
1357 | if (!send) |
1251 | { |
1358 | { |
1252 | // generate a new packet, if wise |
1359 | // generate a new packet, if wise |
… | |
… | |
1256 | if (vpn->dns_sndpq.empty ()) |
1363 | if (vpn->dns_sndpq.empty ()) |
1257 | { |
1364 | { |
1258 | send = new dns_snd (this); |
1365 | send = new dns_snd (this); |
1259 | |
1366 | |
1260 | cfg.reset (THISNODE->id); |
1367 | cfg.reset (THISNODE->id); |
|
|
1368 | set_cfg (); |
1261 | send->gen_syn_req (); |
1369 | send->gen_syn_req (); |
1262 | } |
1370 | } |
1263 | } |
1371 | } |
1264 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1372 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1265 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1373 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1266 | { |
1374 | { |
1267 | if (last_sent + send_interval <= ev::ev_now ()) |
1375 | if (last_sent + send_interval <= ev_now ()) |
1268 | { |
1376 | { |
1269 | //printf ("sending data request etc.\n"); //D |
1377 | //printf ("sending data request etc.\n"); //D |
1270 | if (!snddq.empty () || last_received + 1. > ev::ev_now ()) |
1378 | if (!snddq.empty ()) |
1271 | { |
|
|
1272 | poll_interval = send_interval; |
1379 | min_it (next, send_interval); |
1273 | NEXT (ev::ev_now () + send_interval); |
|
|
1274 | } |
|
|
1275 | |
1380 | |
1276 | send = new dns_snd (this); |
1381 | send = new dns_snd (this); |
1277 | send->gen_stream_req (sndseq, snddq); |
1382 | send->gen_stream_req (sndseq, snddq); |
1278 | send->timeout = ev::ev_now () + min_latency * conf.dns_timeout_factor; |
1383 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
1279 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev::ev_now (), min_latency, conf.dns_timeout_factor);//D |
1384 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
1280 | |
1385 | |
1281 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1386 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1282 | } |
1387 | } |
1283 | else |
1388 | else |
1284 | NEXT (last_sent + send_interval); |
1389 | min_it (next, last_sent + send_interval - ev_now ()); |
1285 | } |
1390 | } |
1286 | |
1391 | |
1287 | if (send) |
1392 | if (send) |
1288 | vpn->dns_sndpq.push_back (send); |
1393 | vpn->dns_sndpq.push_back (send); |
1289 | } |
1394 | } |
1290 | |
1395 | |
1291 | if (send) |
1396 | if (send) |
1292 | { |
1397 | { |
1293 | last_sent = ev::ev_now (); |
1398 | last_sent = ev_now (); |
1294 | sendto (vpn->dnsv4_fd, |
1399 | sendto (vpn->dnsv4_fd, |
1295 | send->pkt->at (0), send->pkt->len, 0, |
1400 | send->pkt->at (0), send->pkt->len, 0, |
1296 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1401 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1297 | } |
1402 | } |
1298 | |
1403 | |
|
|
1404 | min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ()); |
|
|
1405 | |
1299 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1406 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1300 | poll_interval, send_interval, next - ev::ev_now (), |
1407 | poll_interval, send_interval, next - ev_now (), |
1301 | vpn->dns_sndpq.size (), snddq.size (), |
1408 | vpn->dns_sndpq.size (), snddq.size (), |
1302 | rcvpq.size ()); |
1409 | rcvpq.size ()); |
1303 | |
1410 | |
1304 | // TODO: no idea when this happens, but when next < ev::ev_now (), we have a problem |
1411 | w.start (next); |
1305 | // doesn't seem to happen anymore |
|
|
1306 | if (next < ev::ev_now () + 0.001) |
|
|
1307 | next = ev::ev_now () + 0.1; |
|
|
1308 | |
|
|
1309 | w.start (next - ev::ev_now ()); |
|
|
1310 | } |
1412 | } |
1311 | |
1413 | |
1312 | #endif |
1414 | #endif |
1313 | |
1415 | |