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. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | |
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20 | Additional permission under GNU GPL version 3 section 7 |
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21 | |
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22 | If you modify this Program, or any covered work, by linking or |
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23 | combining it with the OpenSSL project's OpenSSL library (or a modified |
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24 | version of that library), containing parts covered by the terms of the |
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25 | OpenSSL or SSLeay licenses, the licensors of this Program grant you |
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26 | additional permission to convey the resulting work. Corresponding |
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27 | Source for a non-source form of such a combination shall include the |
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28 | source code for the parts of OpenSSL used as well as that of the |
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29 | covered work. |
20 | */ |
30 | */ |
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31 | |
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32 | // TODO: EDNS0 option to increase dns mtu? |
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33 | // TODO: re-write dns packet parsing/creation using a safe mem-buffer |
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34 | // to ensure no buffer overflows or similar problems. |
21 | |
35 | |
22 | #include "config.h" |
36 | #include "config.h" |
23 | |
37 | |
24 | #if ENABLE_DNS |
38 | #if ENABLE_DNS |
25 | |
39 | |
… | |
… | |
38 | #include <unistd.h> |
52 | #include <unistd.h> |
39 | #include <fcntl.h> |
53 | #include <fcntl.h> |
40 | |
54 | |
41 | #include <map> |
55 | #include <map> |
42 | |
56 | |
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57 | #include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */ |
43 | #include <gmp.h> |
58 | #include <gmp.h> |
44 | |
59 | |
45 | #include "netcompat.h" |
60 | #include "netcompat.h" |
46 | |
61 | |
47 | #include "vpn.h" |
62 | #include "vpn.h" |
48 | |
63 | |
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64 | #define MIN_POLL_INTERVAL 0.1 // poll at most this often when no data received |
49 | #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 |
50 | #define ACTIVITY_INTERVAL 5. |
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51 | |
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52 | #define TIMEOUT_FACTOR 2. |
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53 | |
66 | |
54 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
67 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
55 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
68 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
56 | |
69 | |
57 | #define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests |
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58 | #define MAX_SEND_INTERVAL 2. // optimistic? |
70 | #define MAX_SEND_INTERVAL 2. // optimistic? |
59 | |
71 | |
60 | #define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate |
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61 | #define MAX_OUTSTANDING 100 // max. outstanding requests |
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62 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
72 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
63 | #define MAX_BACKLOG (32*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 |
64 | |
74 | |
65 | #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 |
66 | // 240 leaves about 4 bytes of server reply data |
76 | // 240 leaves about 4 bytes of server reply data |
67 | // every two request bytes less give room for one reply byte |
77 | // every request byte less give room for two reply bytes |
68 | |
78 | |
69 | #define SEQNO_MASK 0x0fff |
79 | #define SEQNO_MASK 0x3fff |
70 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
80 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
71 | |
81 | |
72 | #define MAX_LBL_SIZE 63 |
82 | #define MAX_LBL_SIZE 63 |
73 | #define MAX_PKT_SIZE 512 |
83 | #define MAX_PKT_SIZE 512 |
74 | |
84 | |
75 | #define RR_TYPE_A 1 |
85 | #define RR_TYPE_A 1 |
76 | #define RR_TYPE_NULL 10 |
86 | #define RR_TYPE_NULL 10 |
77 | #define RR_TYPE_TXT 16 |
87 | #define RR_TYPE_TXT 16 |
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88 | #define RR_TYPE_AAAA 28 |
78 | #define RR_TYPE_ANY 255 |
89 | #define RR_TYPE_ANY 255 |
79 | |
90 | |
80 | #define RR_CLASS_IN 1 |
91 | #define RR_CLASS_IN 1 |
81 | |
92 | |
82 | #define CMD_IP_1 207 |
93 | #define CMD_IP_1 207 |
83 | #define CMD_IP_2 46 |
94 | #define CMD_IP_2 46 |
84 | #define CMD_IP_3 236 |
95 | #define CMD_IP_3 236 |
85 | #define CMD_IP_RST 29 |
96 | |
86 | #define CMD_IP_SYN 113 |
97 | #define CMD_IP_RST 29 // some error, reset and retry |
87 | #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 | } |
88 | |
113 | |
89 | // works for cmaps up to 255 (not 256!) |
114 | // works for cmaps up to 255 (not 256!) |
90 | struct charmap |
115 | struct charmap |
91 | { |
116 | { |
92 | enum { INVALID = (u8)255 }; |
117 | enum { INVALID = (u8)255 }; |
… | |
… | |
106 | memset (enc, (char) 0, 256); |
131 | memset (enc, (char) 0, 256); |
107 | memset (dec, (char)INVALID, 256); |
132 | memset (dec, (char)INVALID, 256); |
108 | |
133 | |
109 | for (size = 0; cmap [size]; size++) |
134 | for (size = 0; cmap [size]; size++) |
110 | { |
135 | { |
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136 | char c = cmap [size]; |
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137 | |
111 | enc [size] = cmap [size]; |
138 | enc [size] = c; |
112 | 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; |
113 | } |
144 | } |
114 | |
145 | |
115 | assert (size < 256); |
146 | assert (size < 256); |
116 | } |
147 | } |
117 | |
148 | |
… | |
… | |
124 | { |
155 | { |
125 | charmap cmap; |
156 | charmap cmap; |
126 | unsigned int enc_len [MAX_DEC_LEN]; |
157 | unsigned int enc_len [MAX_DEC_LEN]; |
127 | unsigned int dec_len [MAX_ENC_LEN]; |
158 | unsigned int dec_len [MAX_ENC_LEN]; |
128 | |
159 | |
129 | unsigned int encode_len (unsigned int len); |
160 | unsigned int encode_len (unsigned int len) const; |
130 | unsigned int decode_len (unsigned int len); |
161 | unsigned int decode_len (unsigned int len) const; |
131 | |
162 | |
132 | unsigned int encode (char *dst, u8 *src, unsigned int len); |
163 | unsigned int encode (char *dst, u8 *src, unsigned int len) const; |
133 | unsigned int decode (u8 *dst, char *src, unsigned int len); |
164 | unsigned int decode (u8 *dst, char *src, unsigned int len) const; |
134 | |
165 | |
135 | basecoder (const char *cmap); |
166 | basecoder (const char *cmap); |
136 | }; |
167 | }; |
137 | |
168 | |
138 | basecoder::basecoder (const char *cmap) |
169 | basecoder::basecoder (const char *cmap) |
… | |
… | |
157 | enc_len [len] = n; |
188 | enc_len [len] = n; |
158 | dec_len [n] = len; |
189 | dec_len [n] = len; |
159 | } |
190 | } |
160 | } |
191 | } |
161 | |
192 | |
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193 | unsigned int |
162 | unsigned int basecoder::encode_len (unsigned int len) |
194 | basecoder::encode_len (unsigned int len) const |
163 | { |
195 | { |
164 | return enc_len [len]; |
196 | return enc_len [len]; |
165 | } |
197 | } |
166 | |
198 | |
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199 | unsigned int |
167 | unsigned int basecoder::decode_len (unsigned int len) |
200 | basecoder::decode_len (unsigned int len) const |
168 | { |
201 | { |
169 | while (len && !dec_len [len]) |
202 | while (len && !dec_len [len]) |
170 | --len; |
203 | --len; |
171 | |
204 | |
172 | return dec_len [len]; |
205 | return dec_len [len]; |
173 | } |
206 | } |
174 | |
207 | |
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208 | unsigned int |
175 | unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) |
209 | basecoder::encode (char *dst, u8 *src, unsigned int len) const |
176 | { |
210 | { |
177 | if (!len || len > MAX_DEC_LEN) |
211 | if (!len || len > MAX_DEC_LEN) |
178 | return 0; |
212 | return 0; |
179 | |
213 | |
180 | int elen = encode_len (len); |
214 | int elen = encode_len (len); |
… | |
… | |
199 | *dst++ = cmap.encode [dst_ [i]]; |
233 | *dst++ = cmap.encode [dst_ [i]]; |
200 | |
234 | |
201 | return elen; |
235 | return elen; |
202 | } |
236 | } |
203 | |
237 | |
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238 | unsigned int |
204 | unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) |
239 | basecoder::decode (u8 *dst, char *src, unsigned int len) const |
205 | { |
240 | { |
206 | if (!len || len > MAX_ENC_LEN) |
241 | if (!len || len > MAX_ENC_LEN) |
207 | return 0; |
242 | return 0; |
208 | |
243 | |
209 | u8 src_ [MAX_ENC_LEN]; |
244 | u8 src_ [MAX_ENC_LEN]; |
… | |
… | |
258 | } |
293 | } |
259 | abort (); |
294 | abort (); |
260 | } |
295 | } |
261 | #endif |
296 | #endif |
262 | |
297 | |
263 | //static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-"); |
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264 | //static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); |
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265 | static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); |
298 | static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9 |
266 | //static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet |
299 | static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers |
267 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
300 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z |
268 | |
301 | |
269 | ///////////////////////////////////////////////////////////////////////////// |
302 | ///////////////////////////////////////////////////////////////////////////// |
270 | |
303 | |
271 | #define HDRSIZE 6 |
304 | #define HDRSIZE 5 |
272 | |
305 | |
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306 | inline void |
273 | 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) |
274 | { |
308 | { |
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309 | assert (clientid < 256); |
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310 | |
275 | seqno &= SEQNO_MASK; |
311 | seqno &= SEQNO_MASK; |
276 | |
312 | |
277 | u8 hdr[3] = { |
313 | u8 hdr[3] = { |
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314 | seqno, |
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315 | (seqno >> 8) | (retry << 6), |
278 | clientid, |
316 | clientid, |
279 | (seqno >> 8) | (retry << 6), |
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280 | seqno, |
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281 | }; |
317 | }; |
282 | |
318 | |
283 | assert (clientid < 256); |
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284 | |
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285 | cdc26.encode (data, hdr, 3); |
319 | cdc36.encode (data, hdr, 3); |
286 | } |
320 | } |
287 | |
321 | |
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322 | inline void |
288 | inline void decode_header (char *data, int &clientid, int &seqno) |
323 | decode_header (char *data, int &clientid, int &seqno) |
289 | { |
324 | { |
290 | u8 hdr[3]; |
325 | u8 hdr[3]; |
291 | |
326 | |
292 | cdc26.decode (hdr, data, HDRSIZE); |
327 | cdc36.decode (hdr, data, HDRSIZE); |
293 | |
328 | |
294 | clientid = hdr[0]; |
329 | clientid = hdr[2]; |
295 | seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; |
330 | seqno = ((hdr[1] << 8) | hdr[0]) & SEQNO_MASK; |
296 | } |
331 | } |
297 | |
332 | |
298 | ///////////////////////////////////////////////////////////////////////////// |
333 | ///////////////////////////////////////////////////////////////////////////// |
299 | |
334 | |
300 | struct byte_stream |
335 | struct byte_stream |
… | |
… | |
326 | byte_stream::~byte_stream () |
361 | byte_stream::~byte_stream () |
327 | { |
362 | { |
328 | delete data; |
363 | delete data; |
329 | } |
364 | } |
330 | |
365 | |
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366 | void |
331 | void byte_stream::remove (int count) |
367 | byte_stream::remove (int count) |
332 | { |
368 | { |
333 | if (count > fill) |
369 | if (count > fill) |
334 | assert (count <= fill); |
370 | assert (count <= fill); |
335 | |
371 | |
336 | memmove (data, data + count, fill -= count); |
372 | memmove (data, data + count, fill -= count); |
337 | } |
373 | } |
338 | |
374 | |
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375 | bool |
339 | bool byte_stream::put (u8 *data, unsigned int datalen) |
376 | byte_stream::put (u8 *data, unsigned int datalen) |
340 | { |
377 | { |
341 | if (maxsize - fill < datalen) |
378 | if (maxsize - fill < datalen) |
342 | return false; |
379 | return false; |
343 | |
380 | |
344 | memcpy (this->data + fill, data, datalen); fill += datalen; |
381 | memcpy (this->data + fill, data, datalen); fill += datalen; |
345 | |
382 | |
346 | return true; |
383 | return true; |
347 | } |
384 | } |
348 | |
385 | |
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386 | bool |
349 | bool byte_stream::put (vpn_packet *pkt) |
387 | byte_stream::put (vpn_packet *pkt) |
350 | { |
388 | { |
351 | if (maxsize - fill < pkt->len + 2) |
389 | if (maxsize - fill < pkt->len + 2) |
352 | return false; |
390 | return false; |
353 | |
391 | |
354 | data [fill++] = pkt->len >> 8; |
392 | data [fill++] = pkt->len >> 8; |
… | |
… | |
410 | |
448 | |
411 | struct dns_cfg |
449 | struct dns_cfg |
412 | { |
450 | { |
413 | static int next_uid; |
451 | static int next_uid; |
414 | |
452 | |
415 | 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 |
416 | |
456 | |
417 | u8 version; |
457 | u8 version; |
418 | u8 flags; |
458 | u8 flags; |
419 | 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; |
420 | u8 def_ttl; |
464 | u8 def_ttl; |
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465 | u8 r0; |
421 | |
466 | |
422 | u16 client; |
467 | u8 syn_cdc; // cdc en/decoder for syn (A?) requests |
423 | 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 |
424 | |
471 | |
425 | u16 max_size; |
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426 | u8 seq_cdc; |
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427 | u8 req_cdc; |
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428 | |
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429 | u8 rep_cdc; |
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430 | u8 delay; // time in 0.01s units that the server may delay replying packets |
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431 | u8 r3, r4; |
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432 | |
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433 | u8 r5, r6, r7, r8; |
472 | u8 r1, r2, r3, r4; |
434 | |
473 | |
435 | void reset (int clientid); |
474 | void reset (int clientid); |
436 | bool valid (); |
475 | bool valid (); |
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476 | u8 get_chksum (); |
437 | }; |
477 | }; |
438 | |
478 | |
439 | int dns_cfg::next_uid; |
479 | int dns_cfg::next_uid; |
440 | |
480 | |
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481 | void |
441 | void dns_cfg::reset (int clientid) |
482 | dns_cfg::reset (int clientid) |
442 | { |
483 | { |
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484 | // this ID must result in some mixed-case characters in cdc26-encoding |
443 | id1 = 'G'; |
485 | id1 = 'G'; |
444 | id2 = 'V'; |
486 | id2 = 'V'; |
445 | id3 = 'P'; |
487 | id3 = 'P'; |
446 | id4 = 'E'; |
488 | id4 = 'E'; |
447 | |
489 | |
448 | version = 1; |
490 | version = 2; |
449 | |
491 | |
450 | rrtype = RR_TYPE_TXT; |
492 | rrtype = RR_TYPE_TXT; |
451 | flags = 0; |
493 | flags = 0; |
452 | def_ttl = 0; |
494 | def_ttl = 0; |
453 | seq_cdc = 26; |
495 | syn_cdc = 26; |
454 | req_cdc = 62; |
496 | hdr_cdc = 36; |
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497 | req_cdc = conf.dns_case_preserving ? 62 : 36; |
455 | rep_cdc = 0; |
498 | rep_cdc = 0; |
456 | max_size = htons (MAX_PKT_SIZE); |
499 | max_size = htons (MAX_PKT_SIZE); |
457 | client = htons (clientid); |
500 | client = htons (clientid); |
458 | uid = next_uid++; |
501 | uid = ++next_uid; |
459 | delay = 0; |
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460 | |
502 | |
461 | r3 = r4 = 0; |
503 | r0 = r1 = r2 = r3 = r4 = 0; |
462 | r4 = r5 = r6 = r7 = 0; |
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463 | } |
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464 | |
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 |
465 | bool dns_cfg::valid () |
526 | dns_cfg::valid () |
466 | { |
527 | { |
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528 | // although the protocol itself allows for some configurability, |
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529 | // only the following encoding/decoding settings are implemented. |
467 | return id1 == 'G' |
530 | return id1 == 'G' |
468 | && id2 == 'V' |
531 | && id2 == 'V' |
469 | && id3 == 'P' |
532 | && id3 == 'P' |
470 | && id4 == 'E' |
533 | && id4 == 'E' |
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534 | && version == 2 |
471 | && seq_cdc == 26 |
535 | && syn_cdc == 26 |
472 | && req_cdc == 62 |
536 | && hdr_cdc == 36 |
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|
537 | && (req_cdc == 36 || req_cdc == 62) |
473 | && rep_cdc == 0 |
538 | && rep_cdc == 0 |
474 | && version == 1; |
539 | && chksum == get_chksum (); |
475 | } |
540 | } |
476 | |
541 | |
477 | struct dns_packet : net_packet |
542 | struct dns_packet : net_packet |
478 | { |
543 | { |
479 | u16 id; |
544 | u16 id; |
… | |
… | |
483 | u8 data [MAXSIZE - 6 * 2]; |
548 | u8 data [MAXSIZE - 6 * 2]; |
484 | |
549 | |
485 | int decode_label (char *data, int size, int &offs); |
550 | int decode_label (char *data, int size, int &offs); |
486 | }; |
551 | }; |
487 | |
552 | |
|
|
553 | int |
488 | int dns_packet::decode_label (char *data, int size, int &offs) |
554 | dns_packet::decode_label (char *data, int size, int &offs) |
489 | { |
555 | { |
490 | char *orig = data; |
556 | char *orig = data; |
491 | |
557 | |
492 | memset (data, 0, size); |
558 | memset (data, 0, size); |
493 | |
559 | |
… | |
… | |
519 | return data - orig; |
585 | return data - orig; |
520 | } |
586 | } |
521 | |
587 | |
522 | ///////////////////////////////////////////////////////////////////////////// |
588 | ///////////////////////////////////////////////////////////////////////////// |
523 | |
589 | |
|
|
590 | static |
|
|
591 | u16 next_id () |
|
|
592 | { |
524 | static u16 dns_id = 0; // TODO: should be per-vpn |
593 | static u16 dns_id = 0; // TODO: should be per-vpn |
525 | |
594 | |
526 | static u16 next_id () |
|
|
527 | { |
|
|
528 | if (!dns_id) |
595 | if (!dns_id) |
529 | dns_id = time (0); |
596 | dns_id = time (0); |
530 | |
597 | |
531 | // the simplest lsfr with periodicity 65535 i could find |
598 | // the simplest lsfr with periodicity 65535 i could find |
532 | dns_id = (dns_id << 1) |
599 | dns_id = (dns_id << 1) |
… | |
… | |
547 | struct vpn *vpn; |
614 | struct vpn *vpn; |
548 | |
615 | |
549 | dns_cfg cfg; |
616 | dns_cfg cfg; |
550 | |
617 | |
551 | bool established; |
618 | bool established; |
|
|
619 | const basecoder *cdc; |
552 | |
620 | |
553 | tstamp last_received; |
621 | tstamp last_received; |
554 | tstamp last_sent; |
622 | tstamp last_sent; |
555 | double min_latency; |
623 | double min_latency; |
556 | double poll_interval, send_interval; |
624 | double poll_interval, send_interval; |
… | |
… | |
558 | vector<dns_rcv *> rcvpq; |
626 | vector<dns_rcv *> rcvpq; |
559 | |
627 | |
560 | byte_stream rcvdq; int rcvseq; int repseq; |
628 | byte_stream rcvdq; int rcvseq; int repseq; |
561 | byte_stream snddq; int sndseq; |
629 | byte_stream snddq; int sndseq; |
562 | |
630 | |
563 | void time_cb (time_watcher &w); time_watcher tw; |
631 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
564 | 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 |
565 | |
636 | |
566 | dns_connection (connection *c); |
637 | dns_connection (connection *c); |
567 | ~dns_connection (); |
638 | ~dns_connection (); |
568 | }; |
639 | }; |
569 | |
640 | |
… | |
… | |
587 | : dns (dns) |
658 | : dns (dns) |
588 | { |
659 | { |
589 | timeout = 0; |
660 | timeout = 0; |
590 | retry = 0; |
661 | retry = 0; |
591 | seqno = 0; |
662 | seqno = 0; |
592 | sent = NOW; |
663 | sent = ev_now (); |
593 | stdhdr = false; |
664 | stdhdr = false; |
594 | |
665 | |
595 | pkt = new dns_packet; |
666 | pkt = new dns_packet; |
596 | |
667 | |
597 | pkt->id = next_id (); |
668 | pkt->id = next_id (); |
… | |
… | |
600 | dns_snd::~dns_snd () |
671 | dns_snd::~dns_snd () |
601 | { |
672 | { |
602 | delete pkt; |
673 | delete pkt; |
603 | } |
674 | } |
604 | |
675 | |
|
|
676 | static void |
605 | static void append_domain (dns_packet &pkt, int &offs, const char *domain) |
677 | append_domain (dns_packet &pkt, int &offs, const char *domain) |
606 | { |
678 | { |
607 | // add tunnel domain |
679 | // add tunnel domain |
608 | for (;;) |
680 | for (;;) |
609 | { |
681 | { |
610 | const char *end = strchr (domain, '.'); |
682 | const char *end = strchr (domain, '.'); |
… | |
… | |
623 | |
695 | |
624 | domain = end + 1; |
696 | domain = end + 1; |
625 | } |
697 | } |
626 | } |
698 | } |
627 | |
699 | |
|
|
700 | void |
628 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
701 | dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
629 | { |
702 | { |
630 | stdhdr = true; |
703 | stdhdr = true; |
631 | this->seqno = seqno; |
704 | this->seqno = seqno; |
632 | |
705 | |
633 | timeout = NOW + INITIAL_TIMEOUT; |
706 | timeout = ev_now () + INITIAL_TIMEOUT; |
634 | |
707 | |
635 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
708 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
636 | pkt->qdcount = htons (1); |
709 | pkt->qdcount = htons (1); |
637 | |
710 | |
638 | int offs = 6*2; |
711 | int offs = 6*2; |
… | |
… | |
641 | // 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 |
642 | |
715 | |
643 | char enc[256], *encp = enc; |
716 | char enc[256], *encp = enc; |
644 | encode_header (enc, THISNODE->id, seqno); |
717 | encode_header (enc, THISNODE->id, seqno); |
645 | |
718 | |
646 | 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); |
647 | |
720 | |
648 | if (datalen > stream.size ()) |
721 | if (datalen > stream.size ()) |
649 | datalen = stream.size (); |
722 | datalen = stream.size (); |
650 | |
723 | |
651 | int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
724 | int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; |
652 | stream.remove (datalen); |
725 | stream.remove (datalen); |
653 | |
726 | |
654 | while (enclen) |
727 | while (enclen) |
655 | { |
728 | { |
656 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
729 | int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; |
… | |
… | |
671 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
744 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
672 | |
745 | |
673 | pkt->len = offs; |
746 | pkt->len = offs; |
674 | } |
747 | } |
675 | |
748 | |
|
|
749 | void |
676 | void dns_snd::gen_syn_req () |
750 | dns_snd::gen_syn_req () |
677 | { |
751 | { |
678 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
752 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
679 | |
753 | |
680 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
754 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
681 | pkt->qdcount = htons (1); |
755 | pkt->qdcount = htons (1); |
682 | |
756 | |
683 | int offs = 6 * 2; |
757 | int offs = 6 * 2; |
… | |
… | |
723 | |
797 | |
724 | dns_connection::dns_connection (connection *c) |
798 | dns_connection::dns_connection (connection *c) |
725 | : c (c) |
799 | : c (c) |
726 | , rcvdq (MAX_BACKLOG * 2) |
800 | , rcvdq (MAX_BACKLOG * 2) |
727 | , snddq (MAX_BACKLOG) |
801 | , snddq (MAX_BACKLOG) |
728 | , tw (this, &dns_connection::time_cb) |
|
|
729 | { |
802 | { |
|
|
803 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
|
|
804 | |
730 | vpn = c->vpn; |
805 | vpn = c->vpn; |
|
|
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 | } |
731 | |
830 | |
732 | established = false; |
831 | established = false; |
733 | |
832 | |
734 | rcvseq = repseq = sndseq = 0; |
833 | rcvseq = repseq = sndseq = 0; |
735 | |
834 | |
… | |
… | |
737 | poll_interval = 0.5; // starting here |
836 | poll_interval = 0.5; // starting here |
738 | send_interval = 0.5; // starting rate |
837 | send_interval = 0.5; // starting rate |
739 | min_latency = INITIAL_TIMEOUT; |
838 | min_latency = INITIAL_TIMEOUT; |
740 | } |
839 | } |
741 | |
840 | |
742 | dns_connection::~dns_connection () |
841 | void |
|
|
842 | dns_connection::set_cfg () |
743 | { |
843 | { |
744 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
844 | cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62; |
745 | i != rcvpq.end (); |
|
|
746 | ++i) |
|
|
747 | delete *i; |
|
|
748 | } |
845 | } |
749 | |
846 | |
|
|
847 | void |
750 | void dns_connection::receive_rep (dns_rcv *r) |
848 | dns_connection::receive_rep (dns_rcv *r) |
751 | { |
849 | { |
752 | if (r->datalen) |
850 | if (r->datalen) |
753 | { |
851 | { |
754 | last_received = NOW; |
852 | last_received = ev_now (); |
755 | tw.trigger (); |
853 | tw (); |
756 | |
854 | |
757 | poll_interval = send_interval; |
855 | poll_interval = send_interval; |
758 | } |
856 | } |
759 | else |
857 | else |
760 | { |
858 | { |
… | |
… | |
770 | |
868 | |
771 | // find next packet |
869 | // find next packet |
772 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
870 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
773 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
871 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
774 | { |
872 | { |
|
|
873 | //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D |
775 | // enter the packet into our input stream |
874 | // enter the packet into our input stream |
776 | r = *i; |
875 | r = *i; |
777 | |
876 | |
778 | // remove the oldest packet, look forward, as it's oldest first |
877 | // remove the oldest packet, look forward, as it's oldest first |
779 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
878 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
780 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
879 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
781 | { |
880 | { |
|
|
881 | //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D |
782 | delete *j; |
882 | delete *j; |
783 | rcvpq.erase (j); |
883 | rcvpq.erase (j); |
784 | break; |
884 | break; |
785 | } |
885 | } |
786 | |
886 | |
787 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
887 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
788 | |
888 | |
789 | if (!rcvdq.put (r->data, r->datalen)) |
889 | if (!rcvdq.put (r->data, r->datalen)) |
790 | { |
890 | { |
|
|
891 | // MUST never overflow, can be caused by data corruption, TODO |
791 | slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); |
892 | slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)"); |
792 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
893 | reset (); |
|
|
894 | return; |
793 | } |
895 | } |
794 | |
896 | |
795 | while (vpn_packet *pkt = rcvdq.get ()) |
897 | while (vpn_packet *pkt = rcvdq.get ()) |
796 | { |
898 | { |
797 | sockinfo si; |
899 | sockinfo si; |
798 | si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; |
900 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
799 | |
901 | |
800 | vpn->recv_vpn_packet (pkt, si); |
902 | vpn->recv_vpn_packet (pkt, si); |
801 | |
|
|
802 | delete pkt; |
903 | delete pkt; |
803 | } |
904 | } |
804 | |
905 | |
805 | // check for further packets |
906 | // check for further packets |
806 | goto redo; |
907 | goto redo; |
… | |
… | |
849 | { |
950 | { |
850 | // correct class, domain: parse |
951 | // correct class, domain: parse |
851 | int client, seqno; |
952 | int client, seqno; |
852 | decode_header (qname, client, seqno); |
953 | decode_header (qname, client, seqno); |
853 | |
954 | |
854 | u8 data[MAXSIZE]; |
|
|
855 | int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
856 | |
|
|
857 | if (0 < client && client <= conns.size ()) |
955 | if (0 < client && client <= conns.size ()) |
858 | { |
956 | { |
859 | connection *c = conns [client - 1]; |
957 | connection *c = conns [client - 1]; |
860 | dns_connection *dns = c->dns; |
958 | dns_connection *dns = c->dns; |
861 | dns_rcv *rcv; |
959 | dns_rcv *rcv; |
862 | |
960 | |
863 | if (dns) |
961 | if (dns) |
864 | { |
962 | { |
|
|
963 | u8 data[MAXSIZE]; |
|
|
964 | int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE)); |
|
|
965 | |
865 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
966 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
866 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
967 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
867 | { |
968 | { |
868 | // already seen that request: simply reply with the cached reply |
969 | // already seen that request: simply reply with the cached reply |
869 | dns_rcv *r = *i; |
970 | dns_rcv *r = *i; |
… | |
… | |
970 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
1071 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
971 | pkt [offs++] = 0; pkt [offs++] = 0; |
1072 | pkt [offs++] = 0; pkt [offs++] = 0; |
972 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
1073 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
973 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
1074 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
974 | |
1075 | |
975 | slog (L_INFO, _("DNS: client %d connects"), client); |
|
|
976 | |
|
|
977 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
1076 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
978 | pkt [offs++] = CMD_IP_REJ; |
1077 | pkt [offs++] = CMD_IP_REJ; |
979 | |
1078 | |
980 | if (0 < client && client <= conns.size ()) |
1079 | if (0 < client && client <= conns.size ()) |
981 | { |
1080 | { |
982 | connection *c = conns [client - 1]; |
1081 | connection *c = conns [client - 1]; |
983 | |
1082 | |
984 | if (cfg.valid ()) |
1083 | if (cfg.valid ()) |
985 | { |
1084 | { |
986 | pkt [offs - 1] = CMD_IP_SYN; |
1085 | slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc); |
|
|
1086 | |
|
|
1087 | // check for any encoding mismatches - hints at a case problem |
|
|
1088 | char qname2 [MAX_ENC_LEN]; |
|
|
1089 | cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg)); |
987 | |
1090 | |
988 | delete c->dns; |
1091 | delete c->dns; |
|
|
1092 | |
|
|
1093 | pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg))) |
|
|
1094 | ? CMD_IP_CSE : CMD_IP_SYN; |
|
|
1095 | |
989 | c->dns = new dns_connection (c); |
1096 | c->dns = new dns_connection (c); |
990 | c->dns->cfg = cfg; |
1097 | c->dns->cfg = cfg; |
|
|
1098 | c->dns->set_cfg (); |
991 | } |
1099 | } |
992 | } |
1100 | } |
993 | } |
1101 | } |
994 | } |
1102 | } |
995 | |
1103 | |
… | |
… | |
1014 | { |
1122 | { |
1015 | dns_connection *dns = (*i)->dns; |
1123 | dns_connection *dns = (*i)->dns; |
1016 | connection *c = dns->c; |
1124 | connection *c = dns->c; |
1017 | int seqno = (*i)->seqno; |
1125 | int seqno = (*i)->seqno; |
1018 | u8 data[MAXSIZE], *datap = data; |
1126 | u8 data[MAXSIZE], *datap = data; |
|
|
1127 | //printf ("rcv pkt %x\n", seqno);//D |
|
|
1128 | bool back_off = (*i)->retry; |
1019 | |
1129 | |
1020 | if ((*i)->retry) |
1130 | if (back_off) |
1021 | { |
1131 | { |
1022 | dns->send_interval *= 1.01; |
1132 | dns->send_interval *= 1.01; |
1023 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1133 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1024 | dns->send_interval = MAX_SEND_INTERVAL; |
1134 | dns->send_interval = MAX_SEND_INTERVAL; |
1025 | } |
1135 | } |
… | |
… | |
1028 | #if 0 |
1138 | #if 0 |
1029 | dns->send_interval *= 0.999; |
1139 | dns->send_interval *= 0.999; |
1030 | #endif |
1140 | #endif |
1031 | // the latency surely puts an upper bound on |
1141 | // the latency surely puts an upper bound on |
1032 | // the minimum send interval |
1142 | // the minimum send interval |
1033 | double latency = NOW - (*i)->sent; |
1143 | double latency = ev_now () - (*i)->sent; |
1034 | |
1144 | |
1035 | if (latency < dns->min_latency) |
1145 | if (latency < dns->min_latency) |
1036 | dns->min_latency = latency; |
1146 | dns->min_latency = latency; |
1037 | |
1147 | |
1038 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1148 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
1039 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
1149 | dns->send_interval = dns->min_latency * conf.dns_overlap_factor; |
1040 | |
1150 | |
1041 | if (dns->send_interval < MIN_SEND_INTERVAL) |
1151 | if (dns->send_interval < conf.dns_send_interval) |
1042 | dns->send_interval = MIN_SEND_INTERVAL; |
1152 | dns->send_interval = conf.dns_send_interval; |
1043 | } |
1153 | } |
1044 | |
1154 | |
1045 | delete *i; |
1155 | delete *i; |
1046 | dns_sndpq.erase (i); |
1156 | dns_sndpq.erase (i); |
1047 | |
1157 | |
… | |
… | |
1065 | ttl |= pkt [offs++] << 16; |
1175 | ttl |= pkt [offs++] << 16; |
1066 | ttl |= pkt [offs++] << 8; |
1176 | ttl |= pkt [offs++] << 8; |
1067 | ttl |= pkt [offs++]; |
1177 | ttl |= pkt [offs++]; |
1068 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1178 | u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; |
1069 | |
1179 | |
1070 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) |
1180 | if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype) |
1071 | { |
1181 | { |
1072 | if (rdlen <= MAXSIZE - offs) |
1182 | if (rdlen <= MAXSIZE - offs) |
1073 | { |
1183 | { |
1074 | // decode bytes, finally |
1184 | // decode bytes, finally |
1075 | |
1185 | |
… | |
… | |
1101 | { |
1211 | { |
1102 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1212 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1103 | |
1213 | |
1104 | if (ip [3] == CMD_IP_RST) |
1214 | if (ip [3] == CMD_IP_RST) |
1105 | { |
1215 | { |
1106 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1216 | slog (L_DEBUG, _("DNS: got tunnel RST request.")); |
1107 | |
1217 | |
1108 | delete dns; c->dns = 0; |
1218 | dns->reset (); |
1109 | |
|
|
1110 | return; |
1219 | return; |
1111 | } |
1220 | } |
1112 | else if (ip [3] == CMD_IP_SYN) |
1221 | else if (ip [3] == CMD_IP_SYN) |
1113 | { |
1222 | { |
1114 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1223 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1115 | dns->established = true; |
1224 | dns->established = true; |
1116 | } |
1225 | } |
|
|
1226 | else if (ip [3] == CMD_IP_CSE) |
|
|
1227 | { |
|
|
1228 | if (conf.dns_case_preserving) |
|
|
1229 | { |
|
|
1230 | slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol.")); |
|
|
1231 | conf.dns_case_preserving = false; |
|
|
1232 | dns->reset (); |
|
|
1233 | return; |
|
|
1234 | } |
|
|
1235 | else |
|
|
1236 | { |
|
|
1237 | slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us.")); |
|
|
1238 | dns->established = true; |
|
|
1239 | } |
|
|
1240 | } |
1117 | else if (ip [3] == CMD_IP_REJ) |
1241 | else if (ip [3] == CMD_IP_REJ) |
1118 | { |
1242 | { |
1119 | slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); |
1243 | slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us.")); |
1120 | abort (); |
1244 | dns->tw.start (60.); |
1121 | } |
1245 | } |
1122 | else |
1246 | else |
|
|
1247 | { |
1123 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1248 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
|
|
1249 | dns->tw.start (60.); |
|
|
1250 | } |
1124 | } |
1251 | } |
1125 | else |
1252 | else |
1126 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1253 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1127 | ip [0], ip [1], ip [2], ip [3]); |
1254 | ip [0], ip [1], ip [2], ip [3]); |
1128 | |
1255 | |
… | |
… | |
1146 | } |
1273 | } |
1147 | |
1274 | |
1148 | // todo: pkt now used |
1275 | // todo: pkt now used |
1149 | if (datap) |
1276 | if (datap) |
1150 | dns->receive_rep (new dns_rcv (seqno, data, datap - data)); |
1277 | dns->receive_rep (new dns_rcv (seqno, data, datap - data)); |
|
|
1278 | else if (dns_sndpq.empty ()) // no data received, and nothing to send - idle |
|
|
1279 | { |
|
|
1280 | dns->send_interval *= 1.1; |
|
|
1281 | |
|
|
1282 | if (dns->send_interval < MIN_POLL_INTERVAL) |
|
|
1283 | dns->send_interval = MIN_POLL_INTERVAL; |
|
|
1284 | |
|
|
1285 | if (dns->send_interval > MAX_POLL_INTERVAL && !back_off) |
|
|
1286 | dns->send_interval = MAX_POLL_INTERVAL; |
|
|
1287 | } |
1151 | |
1288 | |
1152 | break; |
1289 | break; |
1153 | } |
1290 | } |
1154 | } |
1291 | } |
1155 | |
1292 | |
1156 | void |
1293 | void |
1157 | vpn::dnsv4_ev (io_watcher &w, short revents) |
1294 | vpn::dnsv4_ev (ev::io &w, int revents) |
1158 | { |
1295 | { |
1159 | if (revents & EVENT_READ) |
1296 | if (revents & EV_READ) |
1160 | { |
1297 | { |
1161 | dns_packet *pkt = new dns_packet; |
1298 | dns_packet *pkt = new dns_packet; |
1162 | struct sockaddr_in sa; |
1299 | struct sockaddr_in sa; |
1163 | socklen_t sa_len = sizeof (sa); |
1300 | socklen_t sa_len = sizeof (sa); |
1164 | |
1301 | |
… | |
… | |
1180 | } |
1317 | } |
1181 | |
1318 | |
1182 | bool |
1319 | bool |
1183 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1320 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1184 | { |
1321 | { |
1185 | int client = ntohs (si.port); |
1322 | int client = ntohl (si.host); |
1186 | |
1323 | |
1187 | assert (0 < client && client <= conns.size ()); |
1324 | assert (0 < client && client <= conns.size ()); |
1188 | |
1325 | |
1189 | connection *c = conns [client - 1]; |
1326 | connection *c = conns [client - 1]; |
1190 | |
1327 | |
1191 | if (!c->dns) |
1328 | if (!c->dns) |
1192 | c->dns = new dns_connection (c); |
1329 | c->dns = new dns_connection (c); |
1193 | |
1330 | |
1194 | if (c->dns->snddq.put (pkt)) |
1331 | if (c->dns->snddq.put (pkt)) |
1195 | c->dns->tw.trigger (); |
1332 | c->dns->tw (); |
1196 | |
1333 | |
1197 | // always return true even if the buffer overflows |
1334 | // always return true even if the buffer overflows |
1198 | return true; |
1335 | return true; |
1199 | } |
1336 | } |
1200 | |
1337 | |
|
|
1338 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
|
|
1339 | |
1201 | void |
1340 | void |
1202 | connection::dnsv4_reset_connection () |
1341 | dns_connection::time_cb (ev::timer &w, int revents) |
1203 | { |
|
|
1204 | //delete dns; dns = 0; //TODO |
|
|
1205 | } |
|
|
1206 | |
|
|
1207 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
|
|
1208 | |
|
|
1209 | void |
|
|
1210 | dns_connection::time_cb (time_watcher &w) |
|
|
1211 | { |
1342 | { |
1212 | // servers have to be polled |
1343 | // servers have to be polled |
1213 | if (THISNODE->dns_port) |
1344 | if (THISNODE->dns_port) |
1214 | return; |
1345 | return; |
1215 | |
1346 | |
1216 | // check for timeouts and (re)transmit |
1347 | // check for timeouts and (re)transmit |
1217 | tstamp next = NOW + poll_interval; |
1348 | tstamp next = ev::now () + poll_interval; |
1218 | dns_snd *send = 0; |
1349 | dns_snd *send = 0; |
1219 | |
1350 | |
1220 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1351 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1221 | i != vpn->dns_sndpq.end (); |
1352 | i != vpn->dns_sndpq.end (); |
1222 | ++i) |
1353 | ++i) |
1223 | { |
1354 | { |
1224 | dns_snd *r = *i; |
1355 | dns_snd *r = *i; |
1225 | |
1356 | |
1226 | if (r->timeout <= NOW) |
1357 | if (r->timeout <= ev_now ()) |
1227 | { |
1358 | { |
1228 | if (!send) |
1359 | if (!send) |
1229 | { |
1360 | { |
1230 | send = r; |
1361 | send = r; |
1231 | |
1362 | |
1232 | r->retry++; |
1363 | r->retry++; |
1233 | r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR); |
1364 | r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); |
|
|
1365 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
1234 | |
1366 | |
1235 | // the following code changes the query section a bit, forcing |
1367 | // the following code changes the query section a bit, forcing |
1236 | // the forwarder to generate a new request |
1368 | // the forwarder to generate a new request |
1237 | if (r->stdhdr) |
1369 | if (r->stdhdr) |
1238 | { |
|
|
1239 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
|
|
1240 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1370 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1241 | } |
|
|
1242 | } |
1371 | } |
1243 | } |
1372 | } |
1244 | else |
1373 | else |
1245 | NEXT (r->timeout); |
1374 | NEXT (r->timeout); |
1246 | } |
1375 | } |
… | |
… | |
1254 | if (vpn->dns_sndpq.empty ()) |
1383 | if (vpn->dns_sndpq.empty ()) |
1255 | { |
1384 | { |
1256 | send = new dns_snd (this); |
1385 | send = new dns_snd (this); |
1257 | |
1386 | |
1258 | cfg.reset (THISNODE->id); |
1387 | cfg.reset (THISNODE->id); |
|
|
1388 | set_cfg (); |
1259 | send->gen_syn_req (); |
1389 | send->gen_syn_req (); |
1260 | } |
1390 | } |
1261 | } |
1391 | } |
1262 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1392 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1263 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1393 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1264 | { |
1394 | { |
1265 | if (last_sent + send_interval <= NOW) |
1395 | if (last_sent + send_interval <= ev_now ()) |
1266 | { |
1396 | { |
1267 | //printf ("sending data request etc.\n"); //D |
1397 | //printf ("sending data request etc.\n"); //D |
1268 | if (!snddq.empty () || last_received + 1. > NOW) |
1398 | if (!snddq.empty () || last_received + 1. > ev_now ()) |
1269 | { |
1399 | { |
1270 | poll_interval = send_interval; |
1400 | poll_interval = send_interval; |
1271 | NEXT (NOW + send_interval); |
1401 | NEXT (ev_now () + send_interval); |
1272 | } |
1402 | } |
1273 | |
1403 | |
1274 | send = new dns_snd (this); |
1404 | send = new dns_snd (this); |
1275 | send->gen_stream_req (sndseq, snddq); |
1405 | send->gen_stream_req (sndseq, snddq); |
1276 | send->timeout = NOW + min_latency * TIMEOUT_FACTOR; |
1406 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
|
|
1407 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
1277 | |
1408 | |
1278 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1409 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1279 | } |
1410 | } |
1280 | else |
1411 | else |
1281 | NEXT (last_sent + send_interval); |
1412 | NEXT (last_sent + send_interval); |
… | |
… | |
1285 | vpn->dns_sndpq.push_back (send); |
1416 | vpn->dns_sndpq.push_back (send); |
1286 | } |
1417 | } |
1287 | |
1418 | |
1288 | if (send) |
1419 | if (send) |
1289 | { |
1420 | { |
1290 | last_sent = NOW; |
1421 | last_sent = ev_now (); |
1291 | if (rand () & 15 != 0)//D |
|
|
1292 | sendto (vpn->dnsv4_fd, |
1422 | sendto (vpn->dnsv4_fd, |
1293 | send->pkt->at (0), send->pkt->len, 0, |
1423 | send->pkt->at (0), send->pkt->len, 0, |
1294 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1424 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1295 | } |
1425 | } |
1296 | |
1426 | |
1297 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1427 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1298 | poll_interval, send_interval, next - NOW, |
1428 | poll_interval, send_interval, next - ev_now (), |
1299 | vpn->dns_sndpq.size (), snddq.size (), |
1429 | vpn->dns_sndpq.size (), snddq.size (), |
1300 | rcvpq.size ()); |
1430 | rcvpq.size ()); |
1301 | |
1431 | |
1302 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1432 | // TODO: no idea when this happens, but when next < ev_now (), we have a problem |
|
|
1433 | // doesn't seem to happen anymore |
1303 | if (next < NOW + 0.001) |
1434 | if (next < ev_now () + 0.001) |
1304 | next = NOW + 0.1; |
1435 | next = ev_now () + 0.1; |
1305 | |
1436 | |
1306 | w.start (next); |
1437 | w.start (next - ev_now ()); |
1307 | } |
1438 | } |
1308 | |
1439 | |
1309 | #endif |
1440 | #endif |
1310 | |
1441 | |