8eebd221 |
1 | /* |
2 | * Network proxy abstraction in PuTTY |
3 | * |
4 | * A proxy layer, if necessary, wedges itself between the network |
5 | * code and the higher level backend. |
6 | */ |
7 | |
7983f47e |
8 | #include <assert.h> |
de9aaffb |
9 | #include <ctype.h> |
10 | #include <string.h> |
7983f47e |
11 | |
8eebd221 |
12 | #define DEFINE_PLUG_METHOD_MACROS |
13 | #include "putty.h" |
14 | #include "network.h" |
15 | #include "proxy.h" |
16 | |
4a693cfc |
17 | #define do_proxy_dns(conf) \ |
18 | (conf_get_int(conf, CONF_proxy_dns) == FORCE_ON || \ |
19 | (conf_get_int(conf, CONF_proxy_dns) == AUTO && \ |
20 | conf_get_int(conf, CONF_proxy_type) != PROXY_SOCKS4)) |
b7a189f3 |
21 | |
8eebd221 |
22 | /* |
23 | * Call this when proxy negotiation is complete, so that this |
24 | * socket can begin working normally. |
25 | */ |
26 | void proxy_activate (Proxy_Socket p) |
27 | { |
28 | void *data; |
29 | int len; |
2d129d8e |
30 | long output_before, output_after; |
31 | |
8eebd221 |
32 | p->state = PROXY_STATE_ACTIVE; |
33 | |
2d129d8e |
34 | /* we want to ignore new receive events until we have sent |
35 | * all of our buffered receive data. |
36 | */ |
8eebd221 |
37 | sk_set_frozen(p->sub_socket, 1); |
38 | |
2d129d8e |
39 | /* how many bytes of output have we buffered? */ |
40 | output_before = bufchain_size(&p->pending_oob_output_data) + |
41 | bufchain_size(&p->pending_output_data); |
42 | /* and keep track of how many bytes do not get sent. */ |
43 | output_after = 0; |
44 | |
0e8f4cda |
45 | /* send buffered OOB writes */ |
8eebd221 |
46 | while (bufchain_size(&p->pending_oob_output_data) > 0) { |
47 | bufchain_prefix(&p->pending_oob_output_data, &data, &len); |
2d129d8e |
48 | output_after += sk_write_oob(p->sub_socket, data, len); |
8eebd221 |
49 | bufchain_consume(&p->pending_oob_output_data, len); |
50 | } |
8eebd221 |
51 | |
0e8f4cda |
52 | /* send buffered normal writes */ |
8eebd221 |
53 | while (bufchain_size(&p->pending_output_data) > 0) { |
54 | bufchain_prefix(&p->pending_output_data, &data, &len); |
2d129d8e |
55 | output_after += sk_write(p->sub_socket, data, len); |
8eebd221 |
56 | bufchain_consume(&p->pending_output_data, len); |
57 | } |
2d129d8e |
58 | |
59 | /* if we managed to send any data, let the higher levels know. */ |
60 | if (output_after < output_before) |
61 | plug_sent(p->plug, output_after); |
8eebd221 |
62 | |
0e8f4cda |
63 | /* if we were asked to flush the output during |
64 | * the proxy negotiation process, do so now. |
65 | */ |
8eebd221 |
66 | if (p->pending_flush) sk_flush(p->sub_socket); |
8eebd221 |
67 | |
bc06669b |
68 | /* if we have a pending EOF to send, send it */ |
69 | if (p->pending_eof) sk_write_eof(p->sub_socket); |
70 | |
2d129d8e |
71 | /* if the backend wanted the socket unfrozen, try to unfreeze. |
72 | * our set_frozen handler will flush buffered receive data before |
73 | * unfreezing the actual underlying socket. |
74 | */ |
75 | if (!p->freeze) |
76 | sk_set_frozen((Socket)p, 0); |
8eebd221 |
77 | } |
78 | |
79 | /* basic proxy socket functions */ |
80 | |
81 | static Plug sk_proxy_plug (Socket s, Plug p) |
82 | { |
83 | Proxy_Socket ps = (Proxy_Socket) s; |
84 | Plug ret = ps->plug; |
85 | if (p) |
86 | ps->plug = p; |
87 | return ret; |
88 | } |
89 | |
90 | static void sk_proxy_close (Socket s) |
91 | { |
92 | Proxy_Socket ps = (Proxy_Socket) s; |
93 | |
8eebd221 |
94 | sk_close(ps->sub_socket); |
f85e6f6e |
95 | sk_addr_free(ps->remote_addr); |
8eebd221 |
96 | sfree(ps); |
97 | } |
98 | |
e0e7dff8 |
99 | static int sk_proxy_write (Socket s, const char *data, int len) |
8eebd221 |
100 | { |
101 | Proxy_Socket ps = (Proxy_Socket) s; |
102 | |
8eebd221 |
103 | if (ps->state != PROXY_STATE_ACTIVE) { |
104 | bufchain_add(&ps->pending_output_data, data, len); |
105 | return bufchain_size(&ps->pending_output_data); |
106 | } |
107 | return sk_write(ps->sub_socket, data, len); |
108 | } |
109 | |
e0e7dff8 |
110 | static int sk_proxy_write_oob (Socket s, const char *data, int len) |
8eebd221 |
111 | { |
112 | Proxy_Socket ps = (Proxy_Socket) s; |
113 | |
8eebd221 |
114 | if (ps->state != PROXY_STATE_ACTIVE) { |
115 | bufchain_clear(&ps->pending_output_data); |
116 | bufchain_clear(&ps->pending_oob_output_data); |
117 | bufchain_add(&ps->pending_oob_output_data, data, len); |
118 | return len; |
119 | } |
120 | return sk_write_oob(ps->sub_socket, data, len); |
121 | } |
122 | |
bc06669b |
123 | static void sk_proxy_write_eof (Socket s) |
124 | { |
125 | Proxy_Socket ps = (Proxy_Socket) s; |
126 | |
127 | if (ps->state != PROXY_STATE_ACTIVE) { |
128 | ps->pending_eof = 1; |
129 | return; |
130 | } |
131 | sk_write_eof(ps->sub_socket); |
132 | } |
133 | |
8eebd221 |
134 | static void sk_proxy_flush (Socket s) |
135 | { |
136 | Proxy_Socket ps = (Proxy_Socket) s; |
137 | |
8eebd221 |
138 | if (ps->state != PROXY_STATE_ACTIVE) { |
139 | ps->pending_flush = 1; |
140 | return; |
141 | } |
142 | sk_flush(ps->sub_socket); |
143 | } |
144 | |
145 | static void sk_proxy_set_private_ptr (Socket s, void *ptr) |
146 | { |
147 | Proxy_Socket ps = (Proxy_Socket) s; |
148 | sk_set_private_ptr(ps->sub_socket, ptr); |
149 | } |
150 | |
151 | static void * sk_proxy_get_private_ptr (Socket s) |
152 | { |
153 | Proxy_Socket ps = (Proxy_Socket) s; |
154 | return sk_get_private_ptr(ps->sub_socket); |
155 | } |
156 | |
157 | static void sk_proxy_set_frozen (Socket s, int is_frozen) |
158 | { |
159 | Proxy_Socket ps = (Proxy_Socket) s; |
160 | |
8eebd221 |
161 | if (ps->state != PROXY_STATE_ACTIVE) { |
162 | ps->freeze = is_frozen; |
163 | return; |
164 | } |
2d129d8e |
165 | |
166 | /* handle any remaining buffered recv data first */ |
167 | if (bufchain_size(&ps->pending_input_data) > 0) { |
168 | ps->freeze = is_frozen; |
169 | |
170 | /* loop while we still have buffered data, and while we are |
171 | * unfrozen. the plug_receive call in the loop could result |
172 | * in a call back into this function refreezing the socket, |
173 | * so we have to check each time. |
174 | */ |
175 | while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) { |
68a49acb |
176 | void *data; |
d9d006d5 |
177 | char databuf[512]; |
2d129d8e |
178 | int len; |
179 | bufchain_prefix(&ps->pending_input_data, &data, &len); |
d9d006d5 |
180 | if (len > lenof(databuf)) |
181 | len = lenof(databuf); |
182 | memcpy(databuf, data, len); |
2d129d8e |
183 | bufchain_consume(&ps->pending_input_data, len); |
d9d006d5 |
184 | plug_receive(ps->plug, 0, databuf, len); |
2d129d8e |
185 | } |
186 | |
187 | /* if we're still frozen, we'll have to wait for another |
188 | * call from the backend to finish unbuffering the data. |
189 | */ |
190 | if (ps->freeze) return; |
191 | } |
192 | |
8eebd221 |
193 | sk_set_frozen(ps->sub_socket, is_frozen); |
194 | } |
195 | |
cbe2d68f |
196 | static const char * sk_proxy_socket_error (Socket s) |
8eebd221 |
197 | { |
198 | Proxy_Socket ps = (Proxy_Socket) s; |
199 | if (ps->error != NULL || ps->sub_socket == NULL) { |
200 | return ps->error; |
201 | } |
202 | return sk_socket_error(ps->sub_socket); |
203 | } |
204 | |
205 | /* basic proxy plug functions */ |
206 | |
7555d6a5 |
207 | static void plug_proxy_log(Plug plug, int type, SockAddr addr, int port, |
208 | const char *error_msg, int error_code) |
209 | { |
210 | Proxy_Plug pp = (Proxy_Plug) plug; |
211 | Proxy_Socket ps = pp->proxy_socket; |
212 | |
213 | plug_log(ps->plug, type, addr, port, error_msg, error_code); |
214 | } |
215 | |
cbe2d68f |
216 | static int plug_proxy_closing (Plug p, const char *error_msg, |
8eebd221 |
217 | int error_code, int calling_back) |
218 | { |
219 | Proxy_Plug pp = (Proxy_Plug) p; |
220 | Proxy_Socket ps = pp->proxy_socket; |
221 | |
8eebd221 |
222 | if (ps->state != PROXY_STATE_ACTIVE) { |
223 | ps->closing_error_msg = error_msg; |
224 | ps->closing_error_code = error_code; |
225 | ps->closing_calling_back = calling_back; |
226 | return ps->negotiate(ps, PROXY_CHANGE_CLOSING); |
227 | } |
228 | return plug_closing(ps->plug, error_msg, |
229 | error_code, calling_back); |
230 | } |
231 | |
232 | static int plug_proxy_receive (Plug p, int urgent, char *data, int len) |
233 | { |
234 | Proxy_Plug pp = (Proxy_Plug) p; |
235 | Proxy_Socket ps = pp->proxy_socket; |
236 | |
8eebd221 |
237 | if (ps->state != PROXY_STATE_ACTIVE) { |
238 | /* we will lose the urgentness of this data, but since most, |
239 | * if not all, of this data will be consumed by the negotiation |
240 | * process, hopefully it won't affect the protocol above us |
241 | */ |
242 | bufchain_add(&ps->pending_input_data, data, len); |
243 | ps->receive_urgent = urgent; |
244 | ps->receive_data = data; |
245 | ps->receive_len = len; |
246 | return ps->negotiate(ps, PROXY_CHANGE_RECEIVE); |
247 | } |
248 | return plug_receive(ps->plug, urgent, data, len); |
249 | } |
250 | |
251 | static void plug_proxy_sent (Plug p, int bufsize) |
252 | { |
253 | Proxy_Plug pp = (Proxy_Plug) p; |
254 | Proxy_Socket ps = pp->proxy_socket; |
255 | |
8eebd221 |
256 | if (ps->state != PROXY_STATE_ACTIVE) { |
257 | ps->sent_bufsize = bufsize; |
258 | ps->negotiate(ps, PROXY_CHANGE_SENT); |
259 | return; |
260 | } |
261 | plug_sent(ps->plug, bufsize); |
262 | } |
263 | |
f7f9fb5c |
264 | static int plug_proxy_accepting (Plug p, OSSocket sock) |
8eebd221 |
265 | { |
266 | Proxy_Plug pp = (Proxy_Plug) p; |
267 | Proxy_Socket ps = pp->proxy_socket; |
268 | |
8eebd221 |
269 | if (ps->state != PROXY_STATE_ACTIVE) { |
270 | ps->accepting_sock = sock; |
271 | return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING); |
272 | } |
273 | return plug_accepting(ps->plug, sock); |
274 | } |
275 | |
b7a189f3 |
276 | /* |
277 | * This function can accept a NULL pointer as `addr', in which case |
278 | * it will only check the host name. |
279 | */ |
e8fa8f62 |
280 | static int proxy_for_destination (SockAddr addr, char *hostname, int port, |
4a693cfc |
281 | Conf *conf) |
8eebd221 |
282 | { |
283 | int s = 0, e = 0; |
284 | char hostip[64]; |
285 | int hostip_len, hostname_len; |
e8fa8f62 |
286 | const char *exclude_list; |
8eebd221 |
287 | |
b804e1e5 |
288 | /* |
289 | * Check the host name and IP against the hard-coded |
290 | * representations of `localhost'. |
291 | */ |
4a693cfc |
292 | if (!conf_get_int(conf, CONF_even_proxy_localhost) && |
b7a189f3 |
293 | (sk_hostname_is_local(hostname) || |
294 | (addr && sk_address_is_local(addr)))) |
b804e1e5 |
295 | return 0; /* do not proxy */ |
296 | |
8eebd221 |
297 | /* we want a string representation of the IP address for comparisons */ |
b7a189f3 |
298 | if (addr) { |
299 | sk_getaddr(addr, hostip, 64); |
300 | hostip_len = strlen(hostip); |
7ffdbc1a |
301 | } else |
302 | hostip_len = 0; /* placate gcc; shouldn't be required */ |
8eebd221 |
303 | |
8eebd221 |
304 | hostname_len = strlen(hostname); |
305 | |
4a693cfc |
306 | exclude_list = conf_get_str(conf, CONF_proxy_exclude_list); |
8eebd221 |
307 | |
308 | /* now parse the exclude list, and see if either our IP |
309 | * or hostname matches anything in it. |
310 | */ |
311 | |
312 | while (exclude_list[s]) { |
313 | while (exclude_list[s] && |
e93ed432 |
314 | (isspace((unsigned char)exclude_list[s]) || |
8eebd221 |
315 | exclude_list[s] == ',')) s++; |
316 | |
317 | if (!exclude_list[s]) break; |
318 | |
319 | e = s; |
320 | |
321 | while (exclude_list[e] && |
e93ed432 |
322 | (isalnum((unsigned char)exclude_list[e]) || |
8eebd221 |
323 | exclude_list[e] == '-' || |
324 | exclude_list[e] == '.' || |
325 | exclude_list[e] == '*')) e++; |
326 | |
327 | if (exclude_list[s] == '*') { |
328 | /* wildcard at beginning of entry */ |
329 | |
b7a189f3 |
330 | if ((addr && strnicmp(hostip + hostip_len - (e - s - 1), |
331 | exclude_list + s + 1, e - s - 1) == 0) || |
8eebd221 |
332 | strnicmp(hostname + hostname_len - (e - s - 1), |
333 | exclude_list + s + 1, e - s - 1) == 0) |
334 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
335 | |
336 | } else if (exclude_list[e-1] == '*') { |
337 | /* wildcard at end of entry */ |
338 | |
b7a189f3 |
339 | if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) || |
8eebd221 |
340 | strnicmp(hostname, exclude_list + s, e - s - 1) == 0) |
341 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
342 | |
343 | } else { |
344 | /* no wildcard at either end, so let's try an absolute |
345 | * match (ie. a specific IP) |
346 | */ |
347 | |
d6f842e3 |
348 | if (addr && strnicmp(hostip, exclude_list + s, e - s) == 0) |
8eebd221 |
349 | return 0; /* IP/hostname excluded. do not use proxy. */ |
d6f842e3 |
350 | if (strnicmp(hostname, exclude_list + s, e - s) == 0) |
8eebd221 |
351 | return 0; /* IP/hostname excluded. do not use proxy. */ |
352 | } |
353 | |
354 | s = e; |
1b08e5d7 |
355 | |
356 | /* Make sure we really have reached the next comma or end-of-string */ |
357 | while (exclude_list[s] && |
e93ed432 |
358 | !isspace((unsigned char)exclude_list[s]) && |
1b08e5d7 |
359 | exclude_list[s] != ',') s++; |
8eebd221 |
360 | } |
361 | |
362 | /* no matches in the exclude list, so use the proxy */ |
363 | return 1; |
364 | } |
365 | |
e8fa8f62 |
366 | SockAddr name_lookup(char *host, int port, char **canonicalname, |
4a693cfc |
367 | Conf *conf, int addressfamily) |
b7a189f3 |
368 | { |
4a693cfc |
369 | if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE && |
370 | do_proxy_dns(conf) && |
371 | proxy_for_destination(NULL, host, port, conf)) { |
b7a189f3 |
372 | *canonicalname = dupstr(host); |
373 | return sk_nonamelookup(host); |
374 | } |
375 | |
05581745 |
376 | return sk_namelookup(host, canonicalname, addressfamily); |
b7a189f3 |
377 | } |
378 | |
8eebd221 |
379 | Socket new_connection(SockAddr addr, char *hostname, |
380 | int port, int privport, |
79bf227b |
381 | int oobinline, int nodelay, int keepalive, |
4a693cfc |
382 | Plug plug, Conf *conf) |
8eebd221 |
383 | { |
7b6c9b99 |
384 | static const struct socket_function_table socket_fn_table = { |
8eebd221 |
385 | sk_proxy_plug, |
386 | sk_proxy_close, |
387 | sk_proxy_write, |
388 | sk_proxy_write_oob, |
bc06669b |
389 | sk_proxy_write_eof, |
8eebd221 |
390 | sk_proxy_flush, |
391 | sk_proxy_set_private_ptr, |
392 | sk_proxy_get_private_ptr, |
393 | sk_proxy_set_frozen, |
394 | sk_proxy_socket_error |
395 | }; |
396 | |
7b6c9b99 |
397 | static const struct plug_function_table plug_fn_table = { |
7555d6a5 |
398 | plug_proxy_log, |
8eebd221 |
399 | plug_proxy_closing, |
400 | plug_proxy_receive, |
401 | plug_proxy_sent, |
402 | plug_proxy_accepting |
403 | }; |
404 | |
4a693cfc |
405 | if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE && |
406 | proxy_for_destination(addr, hostname, port, conf)) |
8eebd221 |
407 | { |
408 | Proxy_Socket ret; |
409 | Proxy_Plug pplug; |
410 | SockAddr proxy_addr; |
cbe2d68f |
411 | char *proxy_canonical_name; |
0f0a2507 |
412 | Socket sret; |
4a693cfc |
413 | int type; |
0f0a2507 |
414 | |
eba898cf |
415 | if ((sret = platform_new_connection(addr, hostname, port, privport, |
79bf227b |
416 | oobinline, nodelay, keepalive, |
4a693cfc |
417 | plug, conf)) != |
eba898cf |
418 | NULL) |
0f0a2507 |
419 | return sret; |
8eebd221 |
420 | |
3d88e64d |
421 | ret = snew(struct Socket_proxy_tag); |
8eebd221 |
422 | ret->fn = &socket_fn_table; |
4a693cfc |
423 | ret->conf = conf_copy(conf); |
8eebd221 |
424 | ret->plug = plug; |
f85e6f6e |
425 | ret->remote_addr = addr; /* will need to be freed on close */ |
8eebd221 |
426 | ret->remote_port = port; |
427 | |
65c78e88 |
428 | ret->error = NULL; |
429 | ret->pending_flush = 0; |
bc06669b |
430 | ret->pending_eof = 0; |
65c78e88 |
431 | ret->freeze = 0; |
432 | |
8eebd221 |
433 | bufchain_init(&ret->pending_input_data); |
434 | bufchain_init(&ret->pending_output_data); |
435 | bufchain_init(&ret->pending_oob_output_data); |
436 | |
8eebd221 |
437 | ret->sub_socket = NULL; |
438 | ret->state = PROXY_STATE_NEW; |
2d129d8e |
439 | ret->negotiate = NULL; |
4a693cfc |
440 | |
441 | type = conf_get_int(conf, CONF_proxy_type); |
442 | if (type == PROXY_HTTP) { |
8eebd221 |
443 | ret->negotiate = proxy_http_negotiate; |
4a693cfc |
444 | } else if (type == PROXY_SOCKS4) { |
10068a0b |
445 | ret->negotiate = proxy_socks4_negotiate; |
4a693cfc |
446 | } else if (type == PROXY_SOCKS5) { |
10068a0b |
447 | ret->negotiate = proxy_socks5_negotiate; |
4a693cfc |
448 | } else if (type == PROXY_TELNET) { |
8eebd221 |
449 | ret->negotiate = proxy_telnet_negotiate; |
450 | } else { |
7983f47e |
451 | ret->error = "Proxy error: Unknown proxy method"; |
8eebd221 |
452 | return (Socket) ret; |
453 | } |
454 | |
455 | /* create the proxy plug to map calls from the actual |
456 | * socket into our proxy socket layer */ |
3d88e64d |
457 | pplug = snew(struct Plug_proxy_tag); |
8eebd221 |
458 | pplug->fn = &plug_fn_table; |
459 | pplug->proxy_socket = ret; |
460 | |
461 | /* look-up proxy */ |
4a693cfc |
462 | proxy_addr = sk_namelookup(conf_get_str(conf, CONF_proxy_host), |
463 | &proxy_canonical_name, |
464 | conf_get_int(conf, CONF_addressfamily)); |
cbe2d68f |
465 | if (sk_addr_error(proxy_addr) != NULL) { |
42389a9e |
466 | ret->error = "Proxy error: Unable to resolve proxy host name"; |
467 | return (Socket)ret; |
468 | } |
8eebd221 |
469 | sfree(proxy_canonical_name); |
470 | |
471 | /* create the actual socket we will be using, |
472 | * connected to our proxy server and port. |
473 | */ |
4a693cfc |
474 | ret->sub_socket = sk_new(proxy_addr, |
475 | conf_get_int(conf, CONF_proxy_port), |
8eebd221 |
476 | privport, oobinline, |
79bf227b |
477 | nodelay, keepalive, (Plug) pplug); |
8eebd221 |
478 | if (sk_socket_error(ret->sub_socket) != NULL) |
479 | return (Socket) ret; |
480 | |
8eebd221 |
481 | /* start the proxy negotiation process... */ |
482 | sk_set_frozen(ret->sub_socket, 0); |
483 | ret->negotiate(ret, PROXY_CHANGE_NEW); |
484 | |
485 | return (Socket) ret; |
486 | } |
487 | |
488 | /* no proxy, so just return the direct socket */ |
79bf227b |
489 | return sk_new(addr, port, privport, oobinline, nodelay, keepalive, plug); |
8eebd221 |
490 | } |
491 | |
e8fa8f62 |
492 | Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only, |
4a693cfc |
493 | Conf *conf, int addressfamily) |
8eebd221 |
494 | { |
495 | /* TODO: SOCKS (and potentially others) support inbound |
496 | * TODO: connections via the proxy. support them. |
497 | */ |
498 | |
05581745 |
499 | return sk_newlistener(srcaddr, port, plug, local_host_only, addressfamily); |
8eebd221 |
500 | } |
501 | |
502 | /* ---------------------------------------------------------------------- |
503 | * HTTP CONNECT proxy type. |
504 | */ |
505 | |
506 | static int get_line_end (char * data, int len) |
507 | { |
508 | int off = 0; |
509 | |
510 | while (off < len) |
511 | { |
512 | if (data[off] == '\n') { |
513 | /* we have a newline */ |
514 | off++; |
515 | |
516 | /* is that the only thing on this line? */ |
517 | if (off <= 2) return off; |
518 | |
519 | /* if not, then there is the possibility that this header |
520 | * continues onto the next line, if it starts with a space |
521 | * or a tab. |
522 | */ |
523 | |
524 | if (off + 1 < len && |
525 | data[off+1] != ' ' && |
526 | data[off+1] != '\t') return off; |
527 | |
528 | /* the line does continue, so we have to keep going |
529 | * until we see an the header's "real" end of line. |
530 | */ |
531 | off++; |
532 | } |
533 | |
534 | off++; |
535 | } |
536 | |
537 | return -1; |
538 | } |
539 | |
540 | int proxy_http_negotiate (Proxy_Socket p, int change) |
541 | { |
542 | if (p->state == PROXY_STATE_NEW) { |
543 | /* we are just beginning the proxy negotiate process, |
544 | * so we'll send off the initial bits of the request. |
545 | * for this proxy method, it's just a simple HTTP |
546 | * request |
547 | */ |
b7a189f3 |
548 | char *buf, dest[512]; |
4a693cfc |
549 | char *username, *password; |
8eebd221 |
550 | |
b7a189f3 |
551 | sk_getaddr(p->remote_addr, dest, lenof(dest)); |
8eebd221 |
552 | |
57356d63 |
553 | buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n", |
554 | dest, p->remote_port, dest, p->remote_port); |
8eebd221 |
555 | sk_write(p->sub_socket, buf, strlen(buf)); |
57356d63 |
556 | sfree(buf); |
8eebd221 |
557 | |
4a693cfc |
558 | username = conf_get_str(p->conf, CONF_proxy_username); |
559 | password = conf_get_str(p->conf, CONF_proxy_password); |
560 | if (username[0] || password[0]) { |
561 | char *buf, *buf2; |
1549e076 |
562 | int i, j, len; |
4a693cfc |
563 | buf = dupprintf("%s:%s", username, password); |
1549e076 |
564 | len = strlen(buf); |
4a693cfc |
565 | buf2 = snewn(len * 4 / 3 + 100, char); |
6c434e1f |
566 | sprintf(buf2, "Proxy-Authorization: Basic "); |
1549e076 |
567 | for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4) |
616a115c |
568 | base64_encode_atom((unsigned char *)(buf+i), |
569 | (len-i > 3 ? 3 : len-i), buf2+j); |
1549e076 |
570 | strcpy(buf2+j, "\r\n"); |
571 | sk_write(p->sub_socket, buf2, strlen(buf2)); |
4a693cfc |
572 | sfree(buf); |
573 | sfree(buf2); |
1549e076 |
574 | } |
575 | |
9ddf18a4 |
576 | sk_write(p->sub_socket, "\r\n", 2); |
1549e076 |
577 | |
8eebd221 |
578 | p->state = 1; |
8eebd221 |
579 | return 0; |
580 | } |
581 | |
582 | if (change == PROXY_CHANGE_CLOSING) { |
583 | /* if our proxy negotiation process involves closing and opening |
584 | * new sockets, then we would want to intercept this closing |
585 | * callback when we were expecting it. if we aren't anticipating |
586 | * a socket close, then some error must have occurred. we'll |
587 | * just pass those errors up to the backend. |
588 | */ |
589 | return plug_closing(p->plug, p->closing_error_msg, |
590 | p->closing_error_code, |
591 | p->closing_calling_back); |
592 | } |
593 | |
594 | if (change == PROXY_CHANGE_SENT) { |
595 | /* some (or all) of what we wrote to the proxy was sent. |
596 | * we don't do anything new, however, until we receive the |
597 | * proxy's response. we might want to set a timer so we can |
598 | * timeout the proxy negotiation after a while... |
599 | */ |
600 | return 0; |
601 | } |
602 | |
603 | if (change == PROXY_CHANGE_ACCEPTING) { |
604 | /* we should _never_ see this, as we are using our socket to |
605 | * connect to a proxy, not accepting inbound connections. |
606 | * what should we do? close the socket with an appropriate |
607 | * error message? |
608 | */ |
609 | return plug_accepting(p->plug, p->accepting_sock); |
610 | } |
611 | |
612 | if (change == PROXY_CHANGE_RECEIVE) { |
613 | /* we have received data from the underlying socket, which |
614 | * we'll need to parse, process, and respond to appropriately. |
615 | */ |
616 | |
7983f47e |
617 | char *data, *datap; |
8eebd221 |
618 | int len; |
619 | int eol; |
620 | |
621 | if (p->state == 1) { |
622 | |
623 | int min_ver, maj_ver, status; |
624 | |
625 | /* get the status line */ |
7983f47e |
626 | len = bufchain_size(&p->pending_input_data); |
627 | assert(len > 0); /* or we wouldn't be here */ |
8d8af571 |
628 | data = snewn(len+1, char); |
7983f47e |
629 | bufchain_fetch(&p->pending_input_data, data, len); |
8d8af571 |
630 | /* |
631 | * We must NUL-terminate this data, because Windows |
632 | * sscanf appears to require a NUL at the end of the |
633 | * string because it strlens it _first_. Sigh. |
634 | */ |
635 | data[len] = '\0'; |
7983f47e |
636 | |
8eebd221 |
637 | eol = get_line_end(data, len); |
7983f47e |
638 | if (eol < 0) { |
639 | sfree(data); |
640 | return 1; |
641 | } |
8eebd221 |
642 | |
7983f47e |
643 | status = -1; |
644 | /* We can't rely on whether the %n incremented the sscanf return */ |
645 | if (sscanf((char *)data, "HTTP/%i.%i %n", |
646 | &maj_ver, &min_ver, &status) < 2 || status == -1) { |
647 | plug_closing(p->plug, "Proxy error: HTTP response was absent", |
648 | PROXY_ERROR_GENERAL, 0); |
649 | sfree(data); |
650 | return 1; |
651 | } |
8eebd221 |
652 | |
653 | /* remove the status line from the input buffer. */ |
654 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
655 | if (data[status] != '2') { |
8eebd221 |
656 | /* error */ |
57356d63 |
657 | char *buf; |
7983f47e |
658 | data[eol] = '\0'; |
659 | while (eol > status && |
660 | (data[eol-1] == '\r' || data[eol-1] == '\n')) |
661 | data[--eol] = '\0'; |
57356d63 |
662 | buf = dupprintf("Proxy error: %s", data+status); |
7983f47e |
663 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
57356d63 |
664 | sfree(buf); |
7983f47e |
665 | sfree(data); |
8eebd221 |
666 | return 1; |
667 | } |
668 | |
7983f47e |
669 | sfree(data); |
670 | |
8eebd221 |
671 | p->state = 2; |
672 | } |
673 | |
674 | if (p->state == 2) { |
675 | |
676 | /* get headers. we're done when we get a |
677 | * header of length 2, (ie. just "\r\n") |
678 | */ |
679 | |
7983f47e |
680 | len = bufchain_size(&p->pending_input_data); |
681 | assert(len > 0); /* or we wouldn't be here */ |
3d88e64d |
682 | data = snewn(len, char); |
7983f47e |
683 | datap = data; |
684 | bufchain_fetch(&p->pending_input_data, data, len); |
685 | |
686 | eol = get_line_end(datap, len); |
687 | if (eol < 0) { |
688 | sfree(data); |
689 | return 1; |
690 | } |
8eebd221 |
691 | while (eol > 2) |
692 | { |
8eebd221 |
693 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
694 | datap += eol; |
9ddf18a4 |
695 | len -= eol; |
7983f47e |
696 | eol = get_line_end(datap, len); |
8eebd221 |
697 | } |
698 | |
699 | if (eol == 2) { |
700 | /* we're done */ |
701 | bufchain_consume(&p->pending_input_data, 2); |
702 | proxy_activate(p); |
703 | /* proxy activate will have dealt with |
704 | * whatever is left of the buffer */ |
7983f47e |
705 | sfree(data); |
8eebd221 |
706 | return 1; |
707 | } |
708 | |
7983f47e |
709 | sfree(data); |
8eebd221 |
710 | return 1; |
711 | } |
712 | } |
713 | |
7983f47e |
714 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
8eebd221 |
715 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
716 | return 1; |
8eebd221 |
717 | } |
718 | |
719 | /* ---------------------------------------------------------------------- |
6971bbe7 |
720 | * SOCKS proxy type. |
8eebd221 |
721 | */ |
722 | |
6971bbe7 |
723 | /* SOCKS version 4 */ |
724 | int proxy_socks4_negotiate (Proxy_Socket p, int change) |
8eebd221 |
725 | { |
6971bbe7 |
726 | if (p->state == PROXY_CHANGE_NEW) { |
727 | |
728 | /* request format: |
729 | * version number (1 byte) = 4 |
730 | * command code (1 byte) |
731 | * 1 = CONNECT |
732 | * 2 = BIND |
733 | * dest. port (2 bytes) [network order] |
734 | * dest. address (4 bytes) |
735 | * user ID (variable length, null terminated string) |
736 | */ |
737 | |
b7a189f3 |
738 | int length, type, namelen; |
739 | char *command, addr[4], hostname[512]; |
4a693cfc |
740 | char *username; |
6971bbe7 |
741 | |
b7a189f3 |
742 | type = sk_addrtype(p->remote_addr); |
743 | if (type == ADDRTYPE_IPV6) { |
7983f47e |
744 | plug_closing(p->plug, "Proxy error: SOCKS version 4 does" |
745 | " not support IPv6", PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
746 | return 1; |
b7a189f3 |
747 | } else if (type == ADDRTYPE_IPV4) { |
748 | namelen = 0; |
749 | sk_addrcopy(p->remote_addr, addr); |
750 | } else { /* type == ADDRTYPE_NAME */ |
5e391f65 |
751 | assert(type == ADDRTYPE_NAME); |
b7a189f3 |
752 | sk_getaddr(p->remote_addr, hostname, lenof(hostname)); |
753 | namelen = strlen(hostname) + 1; /* include the NUL */ |
754 | addr[0] = addr[1] = addr[2] = 0; |
755 | addr[3] = 1; |
6971bbe7 |
756 | } |
757 | |
4a693cfc |
758 | username = conf_get_str(p->conf, CONF_proxy_username); |
759 | length = strlen(username) + namelen + 9; |
3d88e64d |
760 | command = snewn(length, char); |
4a693cfc |
761 | strcpy(command + 8, username); |
6971bbe7 |
762 | |
763 | command[0] = 4; /* version 4 */ |
764 | command[1] = 1; /* CONNECT command */ |
765 | |
766 | /* port */ |
767 | command[2] = (char) (p->remote_port >> 8) & 0xff; |
768 | command[3] = (char) p->remote_port & 0xff; |
769 | |
770 | /* address */ |
b7a189f3 |
771 | memcpy(command + 4, addr, 4); |
772 | |
773 | /* hostname */ |
4a693cfc |
774 | memcpy(command + 8 + strlen(username) + 1, |
b7a189f3 |
775 | hostname, namelen); |
6971bbe7 |
776 | |
777 | sk_write(p->sub_socket, command, length); |
4a693cfc |
778 | sfree(username); |
de9aaffb |
779 | sfree(command); |
6971bbe7 |
780 | |
781 | p->state = 1; |
782 | return 0; |
783 | } |
784 | |
785 | if (change == PROXY_CHANGE_CLOSING) { |
786 | /* if our proxy negotiation process involves closing and opening |
787 | * new sockets, then we would want to intercept this closing |
788 | * callback when we were expecting it. if we aren't anticipating |
789 | * a socket close, then some error must have occurred. we'll |
790 | * just pass those errors up to the backend. |
791 | */ |
792 | return plug_closing(p->plug, p->closing_error_msg, |
793 | p->closing_error_code, |
794 | p->closing_calling_back); |
795 | } |
796 | |
797 | if (change == PROXY_CHANGE_SENT) { |
798 | /* some (or all) of what we wrote to the proxy was sent. |
799 | * we don't do anything new, however, until we receive the |
800 | * proxy's response. we might want to set a timer so we can |
801 | * timeout the proxy negotiation after a while... |
802 | */ |
803 | return 0; |
804 | } |
805 | |
806 | if (change == PROXY_CHANGE_ACCEPTING) { |
807 | /* we should _never_ see this, as we are using our socket to |
808 | * connect to a proxy, not accepting inbound connections. |
809 | * what should we do? close the socket with an appropriate |
810 | * error message? |
811 | */ |
812 | return plug_accepting(p->plug, p->accepting_sock); |
813 | } |
814 | |
815 | if (change == PROXY_CHANGE_RECEIVE) { |
816 | /* we have received data from the underlying socket, which |
817 | * we'll need to parse, process, and respond to appropriately. |
818 | */ |
819 | |
820 | if (p->state == 1) { |
821 | /* response format: |
822 | * version number (1 byte) = 4 |
823 | * reply code (1 byte) |
824 | * 90 = request granted |
825 | * 91 = request rejected or failed |
826 | * 92 = request rejected due to lack of IDENTD on client |
827 | * 93 = request rejected due to difference in user ID |
828 | * (what we sent vs. what IDENTD said) |
829 | * dest. port (2 bytes) |
830 | * dest. address (4 bytes) |
831 | */ |
832 | |
7983f47e |
833 | char data[8]; |
6971bbe7 |
834 | |
7983f47e |
835 | if (bufchain_size(&p->pending_input_data) < 8) |
836 | return 1; /* not got anything yet */ |
837 | |
6971bbe7 |
838 | /* get the response */ |
7983f47e |
839 | bufchain_fetch(&p->pending_input_data, data, 8); |
6971bbe7 |
840 | |
841 | if (data[0] != 0) { |
7983f47e |
842 | plug_closing(p->plug, "Proxy error: SOCKS proxy responded with " |
6971bbe7 |
843 | "unexpected reply code version", |
844 | PROXY_ERROR_GENERAL, 0); |
845 | return 1; |
846 | } |
847 | |
848 | if (data[1] != 90) { |
849 | |
850 | switch (data[1]) { |
851 | case 92: |
7983f47e |
852 | plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client", |
6971bbe7 |
853 | PROXY_ERROR_GENERAL, 0); |
854 | break; |
855 | case 93: |
7983f47e |
856 | plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree", |
6971bbe7 |
857 | PROXY_ERROR_GENERAL, 0); |
858 | break; |
859 | case 91: |
860 | default: |
7983f47e |
861 | plug_closing(p->plug, "Proxy error: Error while communicating with proxy", |
6971bbe7 |
862 | PROXY_ERROR_GENERAL, 0); |
863 | break; |
864 | } |
865 | |
866 | return 1; |
867 | } |
7983f47e |
868 | bufchain_consume(&p->pending_input_data, 8); |
6971bbe7 |
869 | |
870 | /* we're done */ |
871 | proxy_activate(p); |
872 | /* proxy activate will have dealt with |
873 | * whatever is left of the buffer */ |
874 | return 1; |
875 | } |
876 | } |
877 | |
7983f47e |
878 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
6971bbe7 |
879 | PROXY_ERROR_UNEXPECTED, 0); |
880 | return 1; |
881 | } |
882 | |
883 | /* SOCKS version 5 */ |
884 | int proxy_socks5_negotiate (Proxy_Socket p, int change) |
885 | { |
886 | if (p->state == PROXY_CHANGE_NEW) { |
887 | |
888 | /* initial command: |
889 | * version number (1 byte) = 5 |
890 | * number of available authentication methods (1 byte) |
891 | * available authentication methods (1 byte * previous value) |
892 | * authentication methods: |
893 | * 0x00 = no authentication |
894 | * 0x01 = GSSAPI |
895 | * 0x02 = username/password |
896 | * 0x03 = CHAP |
897 | */ |
898 | |
f33ba69e |
899 | char command[5]; |
4a693cfc |
900 | char *username, *password; |
aab91a3e |
901 | int len; |
6971bbe7 |
902 | |
903 | command[0] = 5; /* version 5 */ |
4a693cfc |
904 | username = conf_get_str(p->conf, CONF_proxy_username); |
905 | password = conf_get_str(p->conf, CONF_proxy_password); |
906 | if (username[0] || password[0]) { |
aab91a3e |
907 | command[2] = 0x00; /* no authentication */ |
f33ba69e |
908 | len = 3; |
909 | proxy_socks5_offerencryptedauth (command, &len); |
910 | command[len++] = 0x02; /* username/password */ |
911 | command[1] = len - 2; /* Number of methods supported */ |
aab91a3e |
912 | } else { |
913 | command[1] = 1; /* one methods supported: */ |
914 | command[2] = 0x00; /* no authentication */ |
915 | len = 3; |
916 | } |
6971bbe7 |
917 | |
aab91a3e |
918 | sk_write(p->sub_socket, command, len); |
6971bbe7 |
919 | |
920 | p->state = 1; |
921 | return 0; |
922 | } |
923 | |
924 | if (change == PROXY_CHANGE_CLOSING) { |
925 | /* if our proxy negotiation process involves closing and opening |
926 | * new sockets, then we would want to intercept this closing |
927 | * callback when we were expecting it. if we aren't anticipating |
928 | * a socket close, then some error must have occurred. we'll |
929 | * just pass those errors up to the backend. |
930 | */ |
931 | return plug_closing(p->plug, p->closing_error_msg, |
932 | p->closing_error_code, |
933 | p->closing_calling_back); |
934 | } |
935 | |
936 | if (change == PROXY_CHANGE_SENT) { |
937 | /* some (or all) of what we wrote to the proxy was sent. |
938 | * we don't do anything new, however, until we receive the |
939 | * proxy's response. we might want to set a timer so we can |
940 | * timeout the proxy negotiation after a while... |
941 | */ |
942 | return 0; |
943 | } |
944 | |
945 | if (change == PROXY_CHANGE_ACCEPTING) { |
946 | /* we should _never_ see this, as we are using our socket to |
947 | * connect to a proxy, not accepting inbound connections. |
948 | * what should we do? close the socket with an appropriate |
949 | * error message? |
950 | */ |
951 | return plug_accepting(p->plug, p->accepting_sock); |
952 | } |
953 | |
954 | if (change == PROXY_CHANGE_RECEIVE) { |
955 | /* we have received data from the underlying socket, which |
956 | * we'll need to parse, process, and respond to appropriately. |
957 | */ |
958 | |
6971bbe7 |
959 | if (p->state == 1) { |
960 | |
961 | /* initial response: |
962 | * version number (1 byte) = 5 |
963 | * authentication method (1 byte) |
964 | * authentication methods: |
965 | * 0x00 = no authentication |
966 | * 0x01 = GSSAPI |
f33ba69e |
967 | * 0x02 = username/password |
6971bbe7 |
968 | * 0x03 = CHAP |
969 | * 0xff = no acceptable methods |
970 | */ |
7983f47e |
971 | char data[2]; |
972 | |
973 | if (bufchain_size(&p->pending_input_data) < 2) |
974 | return 1; /* not got anything yet */ |
6971bbe7 |
975 | |
976 | /* get the response */ |
7983f47e |
977 | bufchain_fetch(&p->pending_input_data, data, 2); |
6971bbe7 |
978 | |
979 | if (data[0] != 5) { |
7983f47e |
980 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version", |
6971bbe7 |
981 | PROXY_ERROR_GENERAL, 0); |
982 | return 1; |
983 | } |
984 | |
985 | if (data[1] == 0x00) p->state = 2; /* no authentication needed */ |
986 | else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */ |
987 | else if (data[1] == 0x02) p->state = 5; /* username/password authentication */ |
988 | else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */ |
989 | else { |
7983f47e |
990 | plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication", |
6971bbe7 |
991 | PROXY_ERROR_GENERAL, 0); |
992 | return 1; |
993 | } |
aab91a3e |
994 | bufchain_consume(&p->pending_input_data, 2); |
995 | } |
996 | |
997 | if (p->state == 7) { |
998 | |
999 | /* password authentication reply format: |
1000 | * version number (1 bytes) = 1 |
1001 | * reply code (1 byte) |
1002 | * 0 = succeeded |
1003 | * >0 = failed |
1004 | */ |
7983f47e |
1005 | char data[2]; |
1006 | |
1007 | if (bufchain_size(&p->pending_input_data) < 2) |
1008 | return 1; /* not got anything yet */ |
aab91a3e |
1009 | |
1010 | /* get the response */ |
7983f47e |
1011 | bufchain_fetch(&p->pending_input_data, data, 2); |
aab91a3e |
1012 | |
1013 | if (data[0] != 1) { |
7983f47e |
1014 | plug_closing(p->plug, "Proxy error: SOCKS password " |
1015 | "subnegotiation contained wrong version number", |
aab91a3e |
1016 | PROXY_ERROR_GENERAL, 0); |
1017 | return 1; |
1018 | } |
1019 | |
1020 | if (data[1] != 0) { |
1021 | |
7983f47e |
1022 | plug_closing(p->plug, "Proxy error: SOCKS proxy refused" |
1023 | " password authentication", |
aab91a3e |
1024 | PROXY_ERROR_GENERAL, 0); |
1025 | return 1; |
1026 | } |
1027 | |
1028 | bufchain_consume(&p->pending_input_data, 2); |
1029 | p->state = 2; /* now proceed as authenticated */ |
6971bbe7 |
1030 | } |
1031 | |
f33ba69e |
1032 | if (p->state == 8) { |
1033 | int ret; |
1034 | ret = proxy_socks5_handlechap(p); |
1035 | if (ret) return ret; |
1036 | } |
1037 | |
6971bbe7 |
1038 | if (p->state == 2) { |
1039 | |
1040 | /* request format: |
1041 | * version number (1 byte) = 5 |
1042 | * command code (1 byte) |
1043 | * 1 = CONNECT |
1044 | * 2 = BIND |
1045 | * 3 = UDP ASSOCIATE |
1046 | * reserved (1 byte) = 0x00 |
1047 | * address type (1 byte) |
1048 | * 1 = IPv4 |
1049 | * 3 = domainname (first byte has length, no terminating null) |
1050 | * 4 = IPv6 |
1051 | * dest. address (variable) |
1052 | * dest. port (2 bytes) [network order] |
1053 | */ |
1054 | |
b7a189f3 |
1055 | char command[512]; |
6971bbe7 |
1056 | int len; |
b7a189f3 |
1057 | int type; |
6971bbe7 |
1058 | |
b7a189f3 |
1059 | type = sk_addrtype(p->remote_addr); |
1060 | if (type == ADDRTYPE_IPV4) { |
1061 | len = 10; /* 4 hdr + 4 addr + 2 trailer */ |
6971bbe7 |
1062 | command[3] = 1; /* IPv4 */ |
b7a189f3 |
1063 | sk_addrcopy(p->remote_addr, command+4); |
1064 | } else if (type == ADDRTYPE_IPV6) { |
1065 | len = 22; /* 4 hdr + 16 addr + 2 trailer */ |
6971bbe7 |
1066 | command[3] = 4; /* IPv6 */ |
b7a189f3 |
1067 | sk_addrcopy(p->remote_addr, command+4); |
5e391f65 |
1068 | } else { |
1069 | assert(type == ADDRTYPE_NAME); |
b7a189f3 |
1070 | command[3] = 3; |
1071 | sk_getaddr(p->remote_addr, command+5, 256); |
1072 | command[4] = strlen(command+5); |
1073 | len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */ |
6971bbe7 |
1074 | } |
1075 | |
1076 | command[0] = 5; /* version 5 */ |
1077 | command[1] = 1; /* CONNECT command */ |
1078 | command[2] = 0x00; |
1079 | |
6971bbe7 |
1080 | /* port */ |
1081 | command[len-2] = (char) (p->remote_port >> 8) & 0xff; |
1082 | command[len-1] = (char) p->remote_port & 0xff; |
1083 | |
1084 | sk_write(p->sub_socket, command, len); |
1085 | |
1086 | p->state = 3; |
1087 | return 1; |
1088 | } |
1089 | |
1090 | if (p->state == 3) { |
1091 | |
1092 | /* reply format: |
1093 | * version number (1 bytes) = 5 |
1094 | * reply code (1 byte) |
1095 | * 0 = succeeded |
1096 | * 1 = general SOCKS server failure |
1097 | * 2 = connection not allowed by ruleset |
1098 | * 3 = network unreachable |
1099 | * 4 = host unreachable |
1100 | * 5 = connection refused |
1101 | * 6 = TTL expired |
1102 | * 7 = command not supported |
1103 | * 8 = address type not supported |
1104 | * reserved (1 byte) = x00 |
1105 | * address type (1 byte) |
1106 | * 1 = IPv4 |
1107 | * 3 = domainname (first byte has length, no terminating null) |
1108 | * 4 = IPv6 |
1109 | * server bound address (variable) |
1110 | * server bound port (2 bytes) [network order] |
1111 | */ |
7983f47e |
1112 | char data[5]; |
1113 | int len; |
1114 | |
1115 | /* First 5 bytes of packet are enough to tell its length. */ |
1116 | if (bufchain_size(&p->pending_input_data) < 5) |
1117 | return 1; /* not got anything yet */ |
6971bbe7 |
1118 | |
1119 | /* get the response */ |
7983f47e |
1120 | bufchain_fetch(&p->pending_input_data, data, 5); |
6971bbe7 |
1121 | |
1122 | if (data[0] != 5) { |
7983f47e |
1123 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number", |
6971bbe7 |
1124 | PROXY_ERROR_GENERAL, 0); |
1125 | return 1; |
1126 | } |
1127 | |
1128 | if (data[1] != 0) { |
7983f47e |
1129 | char buf[256]; |
1130 | |
1131 | strcpy(buf, "Proxy error: "); |
6971bbe7 |
1132 | |
1133 | switch (data[1]) { |
7983f47e |
1134 | case 1: strcat(buf, "General SOCKS server failure"); break; |
1135 | case 2: strcat(buf, "Connection not allowed by ruleset"); break; |
1136 | case 3: strcat(buf, "Network unreachable"); break; |
1137 | case 4: strcat(buf, "Host unreachable"); break; |
1138 | case 5: strcat(buf, "Connection refused"); break; |
1139 | case 6: strcat(buf, "TTL expired"); break; |
1140 | case 7: strcat(buf, "Command not supported"); break; |
1141 | case 8: strcat(buf, "Address type not supported"); break; |
1142 | default: sprintf(buf+strlen(buf), |
1143 | "Unrecognised SOCKS error code %d", |
1144 | data[1]); |
6971bbe7 |
1145 | break; |
1146 | } |
7983f47e |
1147 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
1148 | |
1149 | return 1; |
1150 | } |
6971bbe7 |
1151 | |
7983f47e |
1152 | /* |
1153 | * Eat the rest of the reply packet. |
1154 | */ |
1155 | len = 6; /* first 4 bytes, last 2 */ |
1156 | switch (data[3]) { |
1157 | case 1: len += 4; break; /* IPv4 address */ |
1158 | case 4: len += 16; break;/* IPv6 address */ |
1159 | case 3: len += (unsigned char)data[4]; break; /* domain name */ |
1160 | default: |
1161 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned " |
1162 | "unrecognised address format", |
1163 | PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
1164 | return 1; |
1165 | } |
7983f47e |
1166 | if (bufchain_size(&p->pending_input_data) < len) |
1167 | return 1; /* not got whole reply yet */ |
1168 | bufchain_consume(&p->pending_input_data, len); |
6971bbe7 |
1169 | |
1170 | /* we're done */ |
1171 | proxy_activate(p); |
6971bbe7 |
1172 | return 1; |
1173 | } |
1174 | |
1175 | if (p->state == 4) { |
1176 | /* TODO: Handle GSSAPI authentication */ |
2192a8e4 |
1177 | plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication", |
6971bbe7 |
1178 | PROXY_ERROR_GENERAL, 0); |
1179 | return 1; |
1180 | } |
1181 | |
1182 | if (p->state == 5) { |
4a693cfc |
1183 | char *username = conf_get_str(p->conf, CONF_proxy_username); |
1184 | char *password = conf_get_str(p->conf, CONF_proxy_password); |
1185 | if (username[0] || password[0]) { |
1186 | char userpwbuf[255 + 255 + 3]; |
aab91a3e |
1187 | int ulen, plen; |
4a693cfc |
1188 | ulen = strlen(username); |
aab91a3e |
1189 | if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1; |
4a693cfc |
1190 | plen = strlen(password); |
aab91a3e |
1191 | if (plen > 255) plen = 255; if (plen < 1) plen = 1; |
1192 | userpwbuf[0] = 1; /* version number of subnegotiation */ |
1193 | userpwbuf[1] = ulen; |
4a693cfc |
1194 | memcpy(userpwbuf+2, username, ulen); |
aab91a3e |
1195 | userpwbuf[ulen+2] = plen; |
4a693cfc |
1196 | memcpy(userpwbuf+ulen+3, password, plen); |
aab91a3e |
1197 | sk_write(p->sub_socket, userpwbuf, ulen + plen + 3); |
1198 | p->state = 7; |
1199 | } else |
2192a8e4 |
1200 | plug_closing(p->plug, "Proxy error: Server chose " |
aab91a3e |
1201 | "username/password authentication but we " |
1202 | "didn't offer it!", |
6971bbe7 |
1203 | PROXY_ERROR_GENERAL, 0); |
1204 | return 1; |
1205 | } |
1206 | |
1207 | if (p->state == 6) { |
f33ba69e |
1208 | int ret; |
1209 | ret = proxy_socks5_selectchap(p); |
1210 | if (ret) return ret; |
6971bbe7 |
1211 | } |
aab91a3e |
1212 | |
6971bbe7 |
1213 | } |
1214 | |
2192a8e4 |
1215 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
6971bbe7 |
1216 | PROXY_ERROR_UNEXPECTED, 0); |
1217 | return 1; |
8eebd221 |
1218 | } |
1219 | |
1220 | /* ---------------------------------------------------------------------- |
0e8f4cda |
1221 | * `Telnet' proxy type. |
8eebd221 |
1222 | * |
1223 | * (This is for ad-hoc proxies where you connect to the proxy's |
1224 | * telnet port and send a command such as `connect host port'. The |
1225 | * command is configurable, since this proxy type is typically not |
1226 | * standardised or at all well-defined.) |
1227 | */ |
1228 | |
4a693cfc |
1229 | char *format_telnet_command(SockAddr addr, int port, Conf *conf) |
8eebd221 |
1230 | { |
4a693cfc |
1231 | char *fmt = conf_get_str(conf, CONF_proxy_telnet_command); |
0f0a2507 |
1232 | char *ret = NULL; |
1233 | int retlen = 0, retsize = 0; |
1234 | int so = 0, eo = 0; |
1235 | #define ENSURE(n) do { \ |
1236 | if (retsize < retlen + n) { \ |
1237 | retsize = retlen + n + 512; \ |
1238 | ret = sresize(ret, retsize, char); \ |
1239 | } \ |
1240 | } while (0) |
1241 | |
1242 | /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, |
1243 | * %%, %host, %port, %user, and %pass |
1244 | */ |
0e8f4cda |
1245 | |
4a693cfc |
1246 | while (fmt[eo] != 0) { |
0e8f4cda |
1247 | |
0f0a2507 |
1248 | /* scan forward until we hit end-of-line, |
1249 | * or an escape character (\ or %) */ |
4a693cfc |
1250 | while (fmt[eo] != 0 && fmt[eo] != '%' && fmt[eo] != '\\') |
1251 | eo++; |
0e8f4cda |
1252 | |
0f0a2507 |
1253 | /* if we hit eol, break out of our escaping loop */ |
4a693cfc |
1254 | if (fmt[eo] == 0) break; |
0e8f4cda |
1255 | |
0f0a2507 |
1256 | /* if there was any unescaped text before the escape |
1257 | * character, send that now */ |
1258 | if (eo != so) { |
1259 | ENSURE(eo - so); |
4a693cfc |
1260 | memcpy(ret + retlen, fmt + so, eo - so); |
0f0a2507 |
1261 | retlen += eo - so; |
1262 | } |
0e8f4cda |
1263 | |
0f0a2507 |
1264 | so = eo++; |
0e8f4cda |
1265 | |
0f0a2507 |
1266 | /* if the escape character was the last character of |
1267 | * the line, we'll just stop and send it. */ |
4a693cfc |
1268 | if (fmt[eo] == 0) break; |
0e8f4cda |
1269 | |
4a693cfc |
1270 | if (fmt[so] == '\\') { |
0e8f4cda |
1271 | |
0f0a2507 |
1272 | /* we recognize \\, \%, \r, \n, \t, \x??. |
1273 | * anything else, we just send unescaped (including the \). |
1274 | */ |
0e8f4cda |
1275 | |
4a693cfc |
1276 | switch (fmt[eo]) { |
0f0a2507 |
1277 | |
1278 | case '\\': |
1279 | ENSURE(1); |
1280 | ret[retlen++] = '\\'; |
1281 | eo++; |
1282 | break; |
1283 | |
1284 | case '%': |
1285 | ENSURE(1); |
1286 | ret[retlen++] = '%'; |
1287 | eo++; |
1288 | break; |
1289 | |
1290 | case 'r': |
1291 | ENSURE(1); |
1292 | ret[retlen++] = '\r'; |
1293 | eo++; |
1294 | break; |
1295 | |
1296 | case 'n': |
1297 | ENSURE(1); |
1298 | ret[retlen++] = '\n'; |
1299 | eo++; |
1300 | break; |
1301 | |
1302 | case 't': |
1303 | ENSURE(1); |
1304 | ret[retlen++] = '\t'; |
1305 | eo++; |
1306 | break; |
1307 | |
1308 | case 'x': |
1309 | case 'X': |
1310 | { |
0e8f4cda |
1311 | /* escaped hexadecimal value (ie. \xff) */ |
1312 | unsigned char v = 0; |
1313 | int i = 0; |
1314 | |
1315 | for (;;) { |
1316 | eo++; |
4a693cfc |
1317 | if (fmt[eo] >= '0' && fmt[eo] <= '9') |
1318 | v += fmt[eo] - '0'; |
1319 | else if (fmt[eo] >= 'a' && fmt[eo] <= 'f') |
1320 | v += fmt[eo] - 'a' + 10; |
1321 | else if (fmt[eo] >= 'A' && fmt[eo] <= 'F') |
1322 | v += fmt[eo] - 'A' + 10; |
0e8f4cda |
1323 | else { |
1324 | /* non hex character, so we abort and just |
1325 | * send the whole thing unescaped (including \x) |
1326 | */ |
0f0a2507 |
1327 | ENSURE(1); |
1328 | ret[retlen++] = '\\'; |
0e8f4cda |
1329 | eo = so + 1; |
1330 | break; |
1331 | } |
1332 | |
1333 | /* we only extract two hex characters */ |
1334 | if (i == 1) { |
0f0a2507 |
1335 | ENSURE(1); |
1336 | ret[retlen++] = v; |
0e8f4cda |
1337 | eo++; |
1338 | break; |
1339 | } |
1340 | |
1341 | i++; |
1342 | v <<= 4; |
1343 | } |
0e8f4cda |
1344 | } |
0f0a2507 |
1345 | break; |
0e8f4cda |
1346 | |
0f0a2507 |
1347 | default: |
1348 | ENSURE(2); |
4a693cfc |
1349 | memcpy(ret+retlen, fmt + so, 2); |
0f0a2507 |
1350 | retlen += 2; |
1351 | eo++; |
1352 | break; |
0e8f4cda |
1353 | } |
0f0a2507 |
1354 | } else { |
0e8f4cda |
1355 | |
0f0a2507 |
1356 | /* % escape. we recognize %%, %host, %port, %user, %pass. |
c4190b30 |
1357 | * %proxyhost, %proxyport. Anything else we just send |
1358 | * unescaped (including the %). |
0f0a2507 |
1359 | */ |
0e8f4cda |
1360 | |
4a693cfc |
1361 | if (fmt[eo] == '%') { |
0f0a2507 |
1362 | ENSURE(1); |
1363 | ret[retlen++] = '%'; |
1364 | eo++; |
1365 | } |
4a693cfc |
1366 | else if (strnicmp(fmt + eo, "host", 4) == 0) { |
0f0a2507 |
1367 | char dest[512]; |
1368 | int destlen; |
1369 | sk_getaddr(addr, dest, lenof(dest)); |
1370 | destlen = strlen(dest); |
1371 | ENSURE(destlen); |
1372 | memcpy(ret+retlen, dest, destlen); |
1373 | retlen += destlen; |
1374 | eo += 4; |
1375 | } |
4a693cfc |
1376 | else if (strnicmp(fmt + eo, "port", 4) == 0) { |
0f0a2507 |
1377 | char portstr[8], portlen; |
1378 | portlen = sprintf(portstr, "%i", port); |
1379 | ENSURE(portlen); |
1380 | memcpy(ret + retlen, portstr, portlen); |
1381 | retlen += portlen; |
1382 | eo += 4; |
1383 | } |
4a693cfc |
1384 | else if (strnicmp(fmt + eo, "user", 4) == 0) { |
1385 | char *username = conf_get_str(conf, CONF_proxy_username); |
1386 | int userlen = strlen(username); |
0f0a2507 |
1387 | ENSURE(userlen); |
4a693cfc |
1388 | memcpy(ret+retlen, username, userlen); |
0f0a2507 |
1389 | retlen += userlen; |
1390 | eo += 4; |
1391 | } |
4a693cfc |
1392 | else if (strnicmp(fmt + eo, "pass", 4) == 0) { |
1393 | char *password = conf_get_str(conf, CONF_proxy_password); |
1394 | int passlen = strlen(password); |
0f0a2507 |
1395 | ENSURE(passlen); |
4a693cfc |
1396 | memcpy(ret+retlen, password, passlen); |
0f0a2507 |
1397 | retlen += passlen; |
1398 | eo += 4; |
1399 | } |
4a693cfc |
1400 | else if (strnicmp(fmt + eo, "proxyhost", 9) == 0) { |
1401 | char *host = conf_get_str(conf, CONF_proxy_host); |
1402 | int phlen = strlen(host); |
c4190b30 |
1403 | ENSURE(phlen); |
4a693cfc |
1404 | memcpy(ret+retlen, host, phlen); |
c4190b30 |
1405 | retlen += phlen; |
1406 | eo += 9; |
1407 | } |
4a693cfc |
1408 | else if (strnicmp(fmt + eo, "proxyport", 9) == 0) { |
1409 | int port = conf_get_int(conf, CONF_proxy_port); |
c4190b30 |
1410 | char pport[50]; |
1411 | int pplen; |
4a693cfc |
1412 | sprintf(pport, "%d", port); |
3d291a54 |
1413 | pplen = strlen(pport); |
c4190b30 |
1414 | ENSURE(pplen); |
1415 | memcpy(ret+retlen, pport, pplen); |
1416 | retlen += pplen; |
1417 | eo += 9; |
1418 | } |
0f0a2507 |
1419 | else { |
1420 | /* we don't escape this, so send the % now, and |
1421 | * don't advance eo, so that we'll consider the |
1422 | * text immediately following the % as unescaped. |
1423 | */ |
1424 | ENSURE(1); |
1425 | ret[retlen++] = '%'; |
1426 | } |
0e8f4cda |
1427 | } |
1428 | |
0f0a2507 |
1429 | /* resume scanning for additional escapes after this one. */ |
1430 | so = eo; |
1431 | } |
1432 | |
1433 | /* if there is any unescaped text at the end of the line, send it */ |
1434 | if (eo != so) { |
1435 | ENSURE(eo - so); |
4a693cfc |
1436 | memcpy(ret + retlen, fmt + so, eo - so); |
0f0a2507 |
1437 | retlen += eo - so; |
1438 | } |
1439 | |
1440 | ENSURE(1); |
1441 | ret[retlen] = '\0'; |
1442 | return ret; |
1443 | |
1444 | #undef ENSURE |
1445 | } |
1446 | |
1447 | int proxy_telnet_negotiate (Proxy_Socket p, int change) |
1448 | { |
1449 | if (p->state == PROXY_CHANGE_NEW) { |
1450 | char *formatted_cmd; |
1451 | |
1452 | formatted_cmd = format_telnet_command(p->remote_addr, p->remote_port, |
4a693cfc |
1453 | p->conf); |
0f0a2507 |
1454 | |
1455 | sk_write(p->sub_socket, formatted_cmd, strlen(formatted_cmd)); |
1456 | sfree(formatted_cmd); |
1457 | |
0e8f4cda |
1458 | p->state = 1; |
0e8f4cda |
1459 | return 0; |
1460 | } |
1461 | |
1462 | if (change == PROXY_CHANGE_CLOSING) { |
1463 | /* if our proxy negotiation process involves closing and opening |
1464 | * new sockets, then we would want to intercept this closing |
1465 | * callback when we were expecting it. if we aren't anticipating |
1466 | * a socket close, then some error must have occurred. we'll |
1467 | * just pass those errors up to the backend. |
1468 | */ |
1469 | return plug_closing(p->plug, p->closing_error_msg, |
1470 | p->closing_error_code, |
1471 | p->closing_calling_back); |
1472 | } |
1473 | |
1474 | if (change == PROXY_CHANGE_SENT) { |
1475 | /* some (or all) of what we wrote to the proxy was sent. |
1476 | * we don't do anything new, however, until we receive the |
1477 | * proxy's response. we might want to set a timer so we can |
1478 | * timeout the proxy negotiation after a while... |
1479 | */ |
1480 | return 0; |
1481 | } |
1482 | |
1483 | if (change == PROXY_CHANGE_ACCEPTING) { |
1484 | /* we should _never_ see this, as we are using our socket to |
1485 | * connect to a proxy, not accepting inbound connections. |
1486 | * what should we do? close the socket with an appropriate |
1487 | * error message? |
1488 | */ |
1489 | return plug_accepting(p->plug, p->accepting_sock); |
1490 | } |
1491 | |
1492 | if (change == PROXY_CHANGE_RECEIVE) { |
1493 | /* we have received data from the underlying socket, which |
1494 | * we'll need to parse, process, and respond to appropriately. |
1495 | */ |
1496 | |
1497 | /* we're done */ |
1498 | proxy_activate(p); |
1499 | /* proxy activate will have dealt with |
1500 | * whatever is left of the buffer */ |
1501 | return 1; |
1502 | } |
1503 | |
2192a8e4 |
1504 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
0e8f4cda |
1505 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
1506 | return 1; |
8eebd221 |
1507 | } |