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 235 // 255 is legal limit, but bind doesn't compress well |
65 | // 240 leaves about 4 bytes of server reply data |
76 | // 240 leaves about 4 bytes of server reply data |
66 | // every request byte less give room for two reply bytes |
77 | // every request byte less give room for two reply bytes |
67 | |
78 | |
68 | #define SEQNO_MASK 0x3fff |
79 | #define SEQNO_MASK 0x3fff |
69 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
80 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
… | |
… | |
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 | |
|
|
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 () |
595 | #if 1 |
528 | { |
|
|
529 | if (!dns_id) |
596 | if (!dns_id) |
530 | dns_id = time (0); |
597 | dns_id = time (0); |
531 | |
598 | |
532 | // the simplest lsfr with periodicity 65535 i could find |
599 | // the simplest lsfr with periodicity 65535 i could find |
533 | dns_id = (dns_id << 1) |
600 | dns_id = (dns_id << 1) |
… | |
… | |
535 | ^ (dns_id >> 2) |
602 | ^ (dns_id >> 2) |
536 | ^ (dns_id >> 4) |
603 | ^ (dns_id >> 4) |
537 | ^ (dns_id >> 15)) & 1); |
604 | ^ (dns_id >> 15)) & 1); |
538 | |
605 | |
539 | return dns_id; |
606 | return dns_id; |
|
|
607 | #else |
|
|
608 | dns_id++;//D |
|
|
609 | |
|
|
610 | return htons (dns_id); |
|
|
611 | #endif |
540 | } |
612 | } |
541 | |
613 | |
542 | struct dns_rcv; |
614 | struct dns_rcv; |
543 | struct dns_snd; |
615 | struct dns_snd; |
544 | |
616 | |
… | |
… | |
548 | struct vpn *vpn; |
620 | struct vpn *vpn; |
549 | |
621 | |
550 | dns_cfg cfg; |
622 | dns_cfg cfg; |
551 | |
623 | |
552 | bool established; |
624 | bool established; |
|
|
625 | const basecoder *cdc; |
553 | |
626 | |
554 | tstamp last_received; |
627 | tstamp last_received; |
555 | tstamp last_sent; |
628 | tstamp last_sent; |
556 | double min_latency; |
629 | double min_latency; |
557 | double poll_interval, send_interval; |
630 | double poll_interval, send_interval; |
… | |
… | |
559 | vector<dns_rcv *> rcvpq; |
632 | vector<dns_rcv *> rcvpq; |
560 | |
633 | |
561 | byte_stream rcvdq; int rcvseq; int repseq; |
634 | byte_stream rcvdq; int rcvseq; int repseq; |
562 | byte_stream snddq; int sndseq; |
635 | byte_stream snddq; int sndseq; |
563 | |
636 | |
564 | void time_cb (time_watcher &w); time_watcher tw; |
637 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
565 | void receive_rep (dns_rcv *r); |
638 | void receive_rep (dns_rcv *r); |
|
|
639 | |
|
|
640 | void reset (); // quite like tcp RST |
|
|
641 | void set_cfg (); // to be called after any cfg changes |
566 | |
642 | |
567 | dns_connection (connection *c); |
643 | dns_connection (connection *c); |
568 | ~dns_connection (); |
644 | ~dns_connection (); |
569 | }; |
645 | }; |
570 | |
646 | |
… | |
… | |
588 | : dns (dns) |
664 | : dns (dns) |
589 | { |
665 | { |
590 | timeout = 0; |
666 | timeout = 0; |
591 | retry = 0; |
667 | retry = 0; |
592 | seqno = 0; |
668 | seqno = 0; |
593 | sent = NOW; |
669 | sent = ev_now (); |
594 | stdhdr = false; |
670 | stdhdr = false; |
595 | |
671 | |
596 | pkt = new dns_packet; |
672 | pkt = new dns_packet; |
597 | |
673 | |
598 | pkt->id = next_id (); |
674 | pkt->id = next_id (); |
… | |
… | |
601 | dns_snd::~dns_snd () |
677 | dns_snd::~dns_snd () |
602 | { |
678 | { |
603 | delete pkt; |
679 | delete pkt; |
604 | } |
680 | } |
605 | |
681 | |
|
|
682 | static void |
606 | static void append_domain (dns_packet &pkt, int &offs, const char *domain) |
683 | append_domain (dns_packet &pkt, int &offs, const char *domain) |
607 | { |
684 | { |
608 | // add tunnel domain |
685 | // add tunnel domain |
609 | for (;;) |
686 | for (;;) |
610 | { |
687 | { |
611 | const char *end = strchr (domain, '.'); |
688 | const char *end = strchr (domain, '.'); |
… | |
… | |
624 | |
701 | |
625 | domain = end + 1; |
702 | domain = end + 1; |
626 | } |
703 | } |
627 | } |
704 | } |
628 | |
705 | |
|
|
706 | void |
629 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
707 | dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
630 | { |
708 | { |
631 | stdhdr = true; |
709 | stdhdr = true; |
632 | this->seqno = seqno; |
710 | this->seqno = seqno; |
633 | |
711 | |
634 | timeout = NOW + INITIAL_TIMEOUT; |
712 | timeout = ev_now () + INITIAL_TIMEOUT; |
635 | |
713 | |
636 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
714 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
637 | pkt->qdcount = htons (1); |
715 | pkt->qdcount = htons (1); |
638 | |
716 | |
639 | int offs = 6*2; |
717 | int offs = 6*2; |
… | |
… | |
642 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
720 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
643 | |
721 | |
644 | char enc[256], *encp = enc; |
722 | char enc[256], *encp = enc; |
645 | encode_header (enc, THISNODE->id, seqno); |
723 | encode_header (enc, THISNODE->id, seqno); |
646 | |
724 | |
647 | int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); |
725 | int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); |
648 | |
726 | |
649 | if (datalen > stream.size ()) |
727 | if (datalen > stream.size ()) |
650 | datalen = stream.size (); |
728 | datalen = stream.size (); |
651 | |
729 | |
652 | int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
730 | int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
653 | stream.remove (datalen); |
731 | stream.remove (datalen); |
654 | |
732 | |
655 | while (enclen) |
733 | while (enclen) |
656 | { |
734 | { |
657 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
735 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
… | |
… | |
672 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
750 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
673 | |
751 | |
674 | pkt->len = offs; |
752 | pkt->len = offs; |
675 | } |
753 | } |
676 | |
754 | |
|
|
755 | void |
677 | void dns_snd::gen_syn_req () |
756 | dns_snd::gen_syn_req () |
678 | { |
757 | { |
679 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
758 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
680 | |
759 | |
681 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
760 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
682 | pkt->qdcount = htons (1); |
761 | pkt->qdcount = htons (1); |
683 | |
762 | |
684 | int offs = 6 * 2; |
763 | int offs = 6 * 2; |
… | |
… | |
724 | |
803 | |
725 | dns_connection::dns_connection (connection *c) |
804 | dns_connection::dns_connection (connection *c) |
726 | : c (c) |
805 | : c (c) |
727 | , rcvdq (MAX_BACKLOG * 2) |
806 | , rcvdq (MAX_BACKLOG * 2) |
728 | , snddq (MAX_BACKLOG) |
807 | , snddq (MAX_BACKLOG) |
729 | , tw (this, &dns_connection::time_cb) |
|
|
730 | { |
808 | { |
|
|
809 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
|
|
810 | |
731 | vpn = c->vpn; |
811 | vpn = c->vpn; |
732 | |
812 | |
|
|
813 | reset (); |
|
|
814 | } |
|
|
815 | |
|
|
816 | dns_connection::~dns_connection () |
|
|
817 | { |
|
|
818 | reset (); |
|
|
819 | } |
|
|
820 | |
|
|
821 | void |
|
|
822 | dns_connection::reset () |
|
|
823 | { |
|
|
824 | while (!rcvpq.empty ()) |
|
|
825 | { |
|
|
826 | delete rcvpq.back (); |
|
|
827 | rcvpq.pop_back (); |
|
|
828 | } |
|
|
829 | |
|
|
830 | for (int i = vpn->dns_sndpq.size (); i--; ) |
|
|
831 | if (vpn->dns_sndpq [i]->dns == this) |
|
|
832 | { |
|
|
833 | vpn->dns_sndpq [i] = vpn->dns_sndpq.back (); |
|
|
834 | vpn->dns_sndpq.pop_back (); |
|
|
835 | } |
|
|
836 | |
733 | established = false; |
837 | established = false; |
734 | |
838 | |
735 | rcvseq = repseq = sndseq = 0; |
839 | rcvseq = repseq = sndseq = 0; |
736 | |
840 | |
737 | last_sent = last_received = 0; |
841 | last_sent = 0; |
738 | poll_interval = 0.5; // starting here |
842 | poll_interval = 0.5; // starting here |
739 | send_interval = 0.5; // starting rate |
843 | send_interval = 0.5; // starting rate |
740 | min_latency = INITIAL_TIMEOUT; |
844 | min_latency = INITIAL_TIMEOUT; |
741 | } |
845 | } |
742 | |
846 | |
743 | dns_connection::~dns_connection () |
847 | void |
|
|
848 | dns_connection::set_cfg () |
744 | { |
849 | { |
745 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
850 | cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62; |
746 | i != rcvpq.end (); |
|
|
747 | ++i) |
|
|
748 | delete *i; |
|
|
749 | } |
851 | } |
750 | |
852 | |
|
|
853 | void |
751 | void dns_connection::receive_rep (dns_rcv *r) |
854 | dns_connection::receive_rep (dns_rcv *r) |
752 | { |
855 | { |
753 | if (r->datalen) |
856 | if (r->datalen) |
754 | { |
857 | poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL); |
755 | last_received = NOW; |
|
|
756 | tw.trigger (); |
|
|
757 | |
|
|
758 | poll_interval = send_interval; |
|
|
759 | } |
|
|
760 | else |
858 | else |
761 | { |
859 | 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 | |
860 | |
768 | rcvpq.push_back (r); |
861 | rcvpq.push_back (r); |
769 | |
862 | |
770 | redo: |
863 | redo: |
771 | |
864 | |
772 | // find next packet |
865 | // find next packet |
773 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
866 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
774 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
867 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
775 | { |
868 | { |
|
|
869 | //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D |
776 | // enter the packet into our input stream |
870 | // enter the packet into our input stream |
777 | r = *i; |
871 | r = *i; |
778 | |
872 | |
779 | // remove the oldest packet, look forward, as it's oldest first |
873 | // remove the oldest packet, look forward, as it's oldest first |
780 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
874 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
781 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
875 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
782 | { |
876 | { |
|
|
877 | //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D |
783 | delete *j; |
878 | delete *j; |
784 | rcvpq.erase (j); |
879 | rcvpq.erase (j); |
785 | break; |
880 | break; |
786 | } |
881 | } |
787 | |
882 | |
788 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
883 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
789 | |
884 | |
790 | if (!rcvdq.put (r->data, r->datalen)) |
885 | if (!rcvdq.put (r->data, r->datalen)) |
791 | { |
886 | { |
|
|
887 | // MUST never overflow, can be caused by data corruption, TODO |
792 | slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); |
888 | slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)"); |
793 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
889 | reset (); |
|
|
890 | return; |
794 | } |
891 | } |
795 | |
892 | |
796 | while (vpn_packet *pkt = rcvdq.get ()) |
893 | while (vpn_packet *pkt = rcvdq.get ()) |
797 | { |
894 | { |
798 | sockinfo si; |
895 | sockinfo si; |
799 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
896 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
800 | |
897 | |
801 | vpn->recv_vpn_packet (pkt, si); |
898 | vpn->recv_vpn_packet (pkt, si); |
802 | |
|
|
803 | delete pkt; |
899 | delete pkt; |
804 | } |
900 | } |
805 | |
901 | |
806 | // check for further packets |
902 | // check for further packets |
807 | goto redo; |
903 | goto redo; |
… | |
… | |
850 | { |
946 | { |
851 | // correct class, domain: parse |
947 | // correct class, domain: parse |
852 | int client, seqno; |
948 | int client, seqno; |
853 | decode_header (qname, client, seqno); |
949 | decode_header (qname, client, seqno); |
854 | |
950 | |
855 | u8 data[MAXSIZE]; |
|
|
856 | int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
857 | |
|
|
858 | if (0 < client && client <= conns.size ()) |
951 | if (0 < client && client <= conns.size ()) |
859 | { |
952 | { |
860 | connection *c = conns [client - 1]; |
953 | connection *c = conns [client - 1]; |
861 | dns_connection *dns = c->dns; |
954 | dns_connection *dns = c->dns; |
862 | dns_rcv *rcv; |
955 | dns_rcv *rcv; |
863 | |
956 | |
864 | if (dns) |
957 | if (dns) |
865 | { |
958 | { |
|
|
959 | u8 data[MAXSIZE]; |
|
|
960 | int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
961 | |
866 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
962 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
867 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
963 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
868 | { |
964 | { |
869 | // already seen that request: simply reply with the cached reply |
965 | // already seen that request: simply reply with the cached reply |
870 | dns_rcv *r = *i; |
966 | dns_rcv *r = *i; |
… | |
… | |
971 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
1067 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
972 | pkt [offs++] = 0; pkt [offs++] = 0; |
1068 | pkt [offs++] = 0; pkt [offs++] = 0; |
973 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
1069 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
974 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
1070 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
975 | |
1071 | |
976 | slog (L_INFO, _("DNS: client %d connects"), client); |
|
|
977 | |
|
|
978 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
1072 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
979 | pkt [offs++] = CMD_IP_REJ; |
1073 | pkt [offs++] = CMD_IP_REJ; |
980 | |
1074 | |
981 | if (0 < client && client <= conns.size ()) |
1075 | if (0 < client && client <= conns.size ()) |
982 | { |
1076 | { |
983 | connection *c = conns [client - 1]; |
1077 | connection *c = conns [client - 1]; |
984 | |
1078 | |
985 | if (cfg.valid ()) |
1079 | if (cfg.valid ()) |
986 | { |
1080 | { |
987 | pkt [offs - 1] = CMD_IP_SYN; |
1081 | slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc); |
|
|
1082 | |
|
|
1083 | // check for any encoding mismatches - hints at a case problem |
|
|
1084 | char qname2 [MAX_ENC_LEN]; |
|
|
1085 | cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg)); |
988 | |
1086 | |
989 | delete c->dns; |
1087 | delete c->dns; |
|
|
1088 | |
|
|
1089 | pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg))) |
|
|
1090 | ? CMD_IP_CSE : CMD_IP_SYN; |
|
|
1091 | |
990 | c->dns = new dns_connection (c); |
1092 | c->dns = new dns_connection (c); |
991 | c->dns->cfg = cfg; |
1093 | c->dns->cfg = cfg; |
|
|
1094 | c->dns->set_cfg (); |
992 | } |
1095 | } |
993 | } |
1096 | } |
994 | } |
1097 | } |
995 | } |
1098 | } |
996 | |
1099 | |
… | |
… | |
1015 | { |
1118 | { |
1016 | dns_connection *dns = (*i)->dns; |
1119 | dns_connection *dns = (*i)->dns; |
1017 | connection *c = dns->c; |
1120 | connection *c = dns->c; |
1018 | int seqno = (*i)->seqno; |
1121 | int seqno = (*i)->seqno; |
1019 | u8 data[MAXSIZE], *datap = data; |
1122 | u8 data[MAXSIZE], *datap = data; |
|
|
1123 | //printf ("rcv pkt %x\n", seqno);//D |
1020 | |
1124 | |
1021 | if ((*i)->retry) |
1125 | if ((*i)->retry) |
1022 | { |
1126 | { |
1023 | dns->send_interval *= 1.01; |
1127 | dns->send_interval *= 1.01; |
1024 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1128 | if (dns->send_interval > MAX_SEND_INTERVAL) |
… | |
… | |
1029 | #if 0 |
1133 | #if 0 |
1030 | dns->send_interval *= 0.999; |
1134 | dns->send_interval *= 0.999; |
1031 | #endif |
1135 | #endif |
1032 | // the latency surely puts an upper bound on |
1136 | // the latency surely puts an upper bound on |
1033 | // the minimum send interval |
1137 | // the minimum send interval |
1034 | double latency = NOW - (*i)->sent; |
1138 | double latency = ev_now () - (*i)->sent; |
1035 | |
1139 | |
1036 | if (latency < dns->min_latency) |
1140 | if (latency < dns->min_latency) |
1037 | dns->min_latency = latency; |
1141 | dns->min_latency = latency; |
1038 | |
1142 | |
1039 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
1143 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
… | |
… | |
1066 | ttl |= pkt [offs++] << 16; |
1170 | ttl |= pkt [offs++] << 16; |
1067 | ttl |= pkt [offs++] << 8; |
1171 | ttl |= pkt [offs++] << 8; |
1068 | ttl |= pkt [offs++]; |
1172 | ttl |= pkt [offs++]; |
1069 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1173 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1070 | |
1174 | |
1071 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) |
1175 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype) |
1072 | { |
1176 | { |
1073 | if (rdlen <= MAXSIZE - offs) |
1177 | if (rdlen <= MAXSIZE - offs) |
1074 | { |
1178 | { |
1075 | // decode bytes, finally |
1179 | // decode bytes, finally |
1076 | |
1180 | |
… | |
… | |
1102 | { |
1206 | { |
1103 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1207 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1104 | |
1208 | |
1105 | if (ip [3] == CMD_IP_RST) |
1209 | if (ip [3] == CMD_IP_RST) |
1106 | { |
1210 | { |
1107 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1211 | slog (L_DEBUG, _("DNS: got tunnel RST request.")); |
1108 | |
1212 | |
1109 | delete dns; c->dns = 0; |
1213 | dns->reset (); |
1110 | |
|
|
1111 | return; |
1214 | return; |
1112 | } |
1215 | } |
1113 | else if (ip [3] == CMD_IP_SYN) |
1216 | else if (ip [3] == CMD_IP_SYN) |
1114 | { |
1217 | { |
1115 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1218 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1116 | dns->established = true; |
1219 | dns->established = true; |
1117 | } |
1220 | } |
|
|
1221 | else if (ip [3] == CMD_IP_CSE) |
|
|
1222 | { |
|
|
1223 | if (conf.dns_case_preserving) |
|
|
1224 | { |
|
|
1225 | slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol.")); |
|
|
1226 | conf.dns_case_preserving = false; |
|
|
1227 | dns->reset (); |
|
|
1228 | return; |
|
|
1229 | } |
|
|
1230 | else |
|
|
1231 | { |
|
|
1232 | slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us.")); |
|
|
1233 | dns->established = true; |
|
|
1234 | } |
|
|
1235 | } |
1118 | else if (ip [3] == CMD_IP_REJ) |
1236 | else if (ip [3] == CMD_IP_REJ) |
1119 | { |
1237 | { |
1120 | slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); |
1238 | slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us.")); |
1121 | abort (); |
1239 | dns->tw.start (60.); |
1122 | } |
1240 | } |
1123 | else |
1241 | else |
|
|
1242 | { |
1124 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1243 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
|
|
1244 | dns->tw.start (60.); |
|
|
1245 | } |
1125 | } |
1246 | } |
1126 | else |
1247 | else |
1127 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1248 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1128 | ip [0], ip [1], ip [2], ip [3]); |
1249 | ip [0], ip [1], ip [2], ip [3]); |
1129 | |
1250 | |
… | |
… | |
1153 | break; |
1274 | break; |
1154 | } |
1275 | } |
1155 | } |
1276 | } |
1156 | |
1277 | |
1157 | void |
1278 | void |
1158 | vpn::dnsv4_ev (io_watcher &w, short revents) |
1279 | vpn::dnsv4_ev (ev::io &w, int revents) |
1159 | { |
1280 | { |
1160 | if (revents & EVENT_READ) |
1281 | if (revents & EV_READ) |
1161 | { |
1282 | { |
1162 | dns_packet *pkt = new dns_packet; |
1283 | dns_packet *pkt = new dns_packet; |
1163 | struct sockaddr_in sa; |
1284 | struct sockaddr_in sa; |
1164 | socklen_t sa_len = sizeof (sa); |
1285 | socklen_t sa_len = sizeof (sa); |
1165 | |
1286 | |
… | |
… | |
1191 | |
1312 | |
1192 | if (!c->dns) |
1313 | if (!c->dns) |
1193 | c->dns = new dns_connection (c); |
1314 | c->dns = new dns_connection (c); |
1194 | |
1315 | |
1195 | if (c->dns->snddq.put (pkt)) |
1316 | if (c->dns->snddq.put (pkt)) |
|
|
1317 | { |
|
|
1318 | min_it (c->dns->poll_interval, 0.25); |
1196 | c->dns->tw.trigger (); |
1319 | c->dns->tw (); |
|
|
1320 | } |
1197 | |
1321 | |
1198 | // always return true even if the buffer overflows |
1322 | // always return true even if the buffer overflows |
1199 | return true; |
1323 | return true; |
1200 | } |
1324 | } |
1201 | |
1325 | |
1202 | void |
1326 | void |
1203 | connection::dnsv4_reset_connection () |
1327 | dns_connection::time_cb (ev::timer &w, int revents) |
1204 | { |
|
|
1205 | //delete dns; dns = 0; //TODO |
|
|
1206 | } |
|
|
1207 | |
|
|
1208 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
|
|
1209 | |
|
|
1210 | void |
|
|
1211 | dns_connection::time_cb (time_watcher &w) |
|
|
1212 | { |
1328 | { |
1213 | // servers have to be polled |
1329 | // servers have to be polled |
1214 | if (THISNODE->dns_port) |
1330 | if (THISNODE->dns_port) |
1215 | return; |
1331 | return; |
1216 | |
1332 | |
1217 | // check for timeouts and (re)transmit |
1333 | // check for timeouts and (re)transmit |
1218 | tstamp next = NOW + poll_interval; |
1334 | tstamp next = 86400 * 365; |
1219 | dns_snd *send = 0; |
1335 | dns_snd *send = 0; |
1220 | |
1336 | |
1221 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1337 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1222 | i != vpn->dns_sndpq.end (); |
1338 | i != vpn->dns_sndpq.end (); |
1223 | ++i) |
1339 | ++i) |
1224 | { |
1340 | { |
1225 | dns_snd *r = *i; |
1341 | dns_snd *r = *i; |
1226 | |
1342 | |
1227 | if (r->timeout <= NOW) |
1343 | if (r->timeout <= ev_now ()) |
1228 | { |
1344 | { |
1229 | if (!send) |
1345 | if (!send) |
1230 | { |
1346 | { |
1231 | send = r; |
1347 | send = r; |
1232 | |
1348 | |
1233 | r->retry++; |
1349 | r->retry++; |
1234 | r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor); |
1350 | r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor; |
|
|
1351 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
1235 | |
1352 | |
1236 | // the following code changes the query section a bit, forcing |
1353 | // the following code changes the query section a bit, forcing |
1237 | // the forwarder to generate a new request |
1354 | // the forwarder to generate a new request |
1238 | if (r->stdhdr) |
1355 | if (r->stdhdr) |
1239 | { |
|
|
1240 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
|
|
1241 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1356 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1242 | } |
|
|
1243 | } |
1357 | } |
1244 | } |
1358 | } |
1245 | else |
1359 | else |
1246 | NEXT (r->timeout); |
1360 | min_it (next, r->timeout - ev_now ()); |
1247 | } |
1361 | } |
1248 | |
1362 | |
1249 | if (!send) |
1363 | if (!send) |
1250 | { |
1364 | { |
1251 | // generate a new packet, if wise |
1365 | // generate a new packet, if wise |
… | |
… | |
1255 | if (vpn->dns_sndpq.empty ()) |
1369 | if (vpn->dns_sndpq.empty ()) |
1256 | { |
1370 | { |
1257 | send = new dns_snd (this); |
1371 | send = new dns_snd (this); |
1258 | |
1372 | |
1259 | cfg.reset (THISNODE->id); |
1373 | cfg.reset (THISNODE->id); |
|
|
1374 | set_cfg (); |
1260 | send->gen_syn_req (); |
1375 | send->gen_syn_req (); |
1261 | } |
1376 | } |
1262 | } |
1377 | } |
1263 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1378 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1264 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1379 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1265 | { |
1380 | { |
1266 | if (last_sent + send_interval <= NOW) |
1381 | if (last_sent + send_interval <= ev_now ()) |
1267 | { |
1382 | { |
1268 | //printf ("sending data request etc.\n"); //D |
1383 | //printf ("sending data request etc.\n"); //D |
1269 | if (!snddq.empty () || last_received + 1. > NOW) |
1384 | if (!snddq.empty ()) |
1270 | { |
|
|
1271 | poll_interval = send_interval; |
|
|
1272 | NEXT (NOW + send_interval); |
1385 | min_it (next, send_interval); |
1273 | } |
|
|
1274 | |
1386 | |
1275 | send = new dns_snd (this); |
1387 | send = new dns_snd (this); |
1276 | send->gen_stream_req (sndseq, snddq); |
1388 | send->gen_stream_req (sndseq, snddq); |
1277 | send->timeout = NOW + min_latency * conf.dns_timeout_factor; |
1389 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
|
|
1390 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
1278 | |
1391 | |
1279 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1392 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1280 | } |
1393 | } |
1281 | else |
1394 | else |
1282 | NEXT (last_sent + send_interval); |
1395 | min_it (next, last_sent + send_interval - ev_now ()); |
1283 | } |
1396 | } |
1284 | |
1397 | |
1285 | if (send) |
1398 | if (send) |
1286 | vpn->dns_sndpq.push_back (send); |
1399 | vpn->dns_sndpq.push_back (send); |
1287 | } |
1400 | } |
1288 | |
1401 | |
1289 | if (send) |
1402 | if (send) |
1290 | { |
1403 | { |
1291 | last_sent = NOW; |
1404 | last_sent = ev_now (); |
1292 | sendto (vpn->dnsv4_fd, |
1405 | sendto (vpn->dnsv4_fd, |
1293 | send->pkt->at (0), send->pkt->len, 0, |
1406 | send->pkt->at (0), send->pkt->len, 0, |
1294 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1407 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1295 | } |
1408 | } |
1296 | |
1409 | |
|
|
1410 | min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ()); |
|
|
1411 | |
1297 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1412 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1298 | poll_interval, send_interval, next - NOW, |
1413 | poll_interval, send_interval, next - ev_now (), |
1299 | vpn->dns_sndpq.size (), snddq.size (), |
1414 | vpn->dns_sndpq.size (), snddq.size (), |
1300 | rcvpq.size ()); |
1415 | rcvpq.size ()); |
1301 | |
1416 | |
1302 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
|
|
1303 | // doesn't seem to happen anymore |
|
|
1304 | if (next < NOW + 0.001) |
|
|
1305 | next = NOW + 0.1; |
|
|
1306 | |
|
|
1307 | w.start (next); |
1417 | w.start (next); |
1308 | } |
1418 | } |
1309 | |
1419 | |
1310 | #endif |
1420 | #endif |
1311 | |
1421 | |