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 | |
e8fa8f62 |
17 | #define do_proxy_dns(cfg) \ |
5ecd7ad0 |
18 | (cfg->proxy_dns == FORCE_ON || \ |
19 | (cfg->proxy_dns == AUTO && cfg->proxy_type != PROXY_SOCKS)) |
b7a189f3 |
20 | |
8eebd221 |
21 | /* |
22 | * Call this when proxy negotiation is complete, so that this |
23 | * socket can begin working normally. |
24 | */ |
25 | void proxy_activate (Proxy_Socket p) |
26 | { |
27 | void *data; |
28 | int len; |
2d129d8e |
29 | long output_before, output_after; |
30 | |
8eebd221 |
31 | p->state = PROXY_STATE_ACTIVE; |
32 | |
2d129d8e |
33 | /* we want to ignore new receive events until we have sent |
34 | * all of our buffered receive data. |
35 | */ |
8eebd221 |
36 | sk_set_frozen(p->sub_socket, 1); |
37 | |
2d129d8e |
38 | /* how many bytes of output have we buffered? */ |
39 | output_before = bufchain_size(&p->pending_oob_output_data) + |
40 | bufchain_size(&p->pending_output_data); |
41 | /* and keep track of how many bytes do not get sent. */ |
42 | output_after = 0; |
43 | |
0e8f4cda |
44 | /* send buffered OOB writes */ |
8eebd221 |
45 | while (bufchain_size(&p->pending_oob_output_data) > 0) { |
46 | bufchain_prefix(&p->pending_oob_output_data, &data, &len); |
2d129d8e |
47 | output_after += sk_write_oob(p->sub_socket, data, len); |
8eebd221 |
48 | bufchain_consume(&p->pending_oob_output_data, len); |
49 | } |
8eebd221 |
50 | |
0e8f4cda |
51 | /* send buffered normal writes */ |
8eebd221 |
52 | while (bufchain_size(&p->pending_output_data) > 0) { |
53 | bufchain_prefix(&p->pending_output_data, &data, &len); |
2d129d8e |
54 | output_after += sk_write(p->sub_socket, data, len); |
8eebd221 |
55 | bufchain_consume(&p->pending_output_data, len); |
56 | } |
2d129d8e |
57 | |
58 | /* if we managed to send any data, let the higher levels know. */ |
59 | if (output_after < output_before) |
60 | plug_sent(p->plug, output_after); |
8eebd221 |
61 | |
0e8f4cda |
62 | /* if we were asked to flush the output during |
63 | * the proxy negotiation process, do so now. |
64 | */ |
8eebd221 |
65 | if (p->pending_flush) sk_flush(p->sub_socket); |
8eebd221 |
66 | |
2d129d8e |
67 | /* if the backend wanted the socket unfrozen, try to unfreeze. |
68 | * our set_frozen handler will flush buffered receive data before |
69 | * unfreezing the actual underlying socket. |
70 | */ |
71 | if (!p->freeze) |
72 | sk_set_frozen((Socket)p, 0); |
8eebd221 |
73 | } |
74 | |
75 | /* basic proxy socket functions */ |
76 | |
77 | static Plug sk_proxy_plug (Socket s, Plug p) |
78 | { |
79 | Proxy_Socket ps = (Proxy_Socket) s; |
80 | Plug ret = ps->plug; |
81 | if (p) |
82 | ps->plug = p; |
83 | return ret; |
84 | } |
85 | |
86 | static void sk_proxy_close (Socket s) |
87 | { |
88 | Proxy_Socket ps = (Proxy_Socket) s; |
89 | |
8eebd221 |
90 | sk_close(ps->sub_socket); |
91 | sfree(ps); |
92 | } |
93 | |
e0e7dff8 |
94 | static int sk_proxy_write (Socket s, const char *data, int len) |
8eebd221 |
95 | { |
96 | Proxy_Socket ps = (Proxy_Socket) s; |
97 | |
8eebd221 |
98 | if (ps->state != PROXY_STATE_ACTIVE) { |
99 | bufchain_add(&ps->pending_output_data, data, len); |
100 | return bufchain_size(&ps->pending_output_data); |
101 | } |
102 | return sk_write(ps->sub_socket, data, len); |
103 | } |
104 | |
e0e7dff8 |
105 | static int sk_proxy_write_oob (Socket s, const char *data, int len) |
8eebd221 |
106 | { |
107 | Proxy_Socket ps = (Proxy_Socket) s; |
108 | |
8eebd221 |
109 | if (ps->state != PROXY_STATE_ACTIVE) { |
110 | bufchain_clear(&ps->pending_output_data); |
111 | bufchain_clear(&ps->pending_oob_output_data); |
112 | bufchain_add(&ps->pending_oob_output_data, data, len); |
113 | return len; |
114 | } |
115 | return sk_write_oob(ps->sub_socket, data, len); |
116 | } |
117 | |
118 | static void sk_proxy_flush (Socket s) |
119 | { |
120 | Proxy_Socket ps = (Proxy_Socket) s; |
121 | |
8eebd221 |
122 | if (ps->state != PROXY_STATE_ACTIVE) { |
123 | ps->pending_flush = 1; |
124 | return; |
125 | } |
126 | sk_flush(ps->sub_socket); |
127 | } |
128 | |
129 | static void sk_proxy_set_private_ptr (Socket s, void *ptr) |
130 | { |
131 | Proxy_Socket ps = (Proxy_Socket) s; |
132 | sk_set_private_ptr(ps->sub_socket, ptr); |
133 | } |
134 | |
135 | static void * sk_proxy_get_private_ptr (Socket s) |
136 | { |
137 | Proxy_Socket ps = (Proxy_Socket) s; |
138 | return sk_get_private_ptr(ps->sub_socket); |
139 | } |
140 | |
141 | static void sk_proxy_set_frozen (Socket s, int is_frozen) |
142 | { |
143 | Proxy_Socket ps = (Proxy_Socket) s; |
144 | |
8eebd221 |
145 | if (ps->state != PROXY_STATE_ACTIVE) { |
146 | ps->freeze = is_frozen; |
147 | return; |
148 | } |
2d129d8e |
149 | |
150 | /* handle any remaining buffered recv data first */ |
151 | if (bufchain_size(&ps->pending_input_data) > 0) { |
152 | ps->freeze = is_frozen; |
153 | |
154 | /* loop while we still have buffered data, and while we are |
155 | * unfrozen. the plug_receive call in the loop could result |
156 | * in a call back into this function refreezing the socket, |
157 | * so we have to check each time. |
158 | */ |
159 | while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) { |
68a49acb |
160 | void *data; |
2d129d8e |
161 | int len; |
162 | bufchain_prefix(&ps->pending_input_data, &data, &len); |
163 | plug_receive(ps->plug, 0, data, len); |
164 | bufchain_consume(&ps->pending_input_data, len); |
165 | } |
166 | |
167 | /* if we're still frozen, we'll have to wait for another |
168 | * call from the backend to finish unbuffering the data. |
169 | */ |
170 | if (ps->freeze) return; |
171 | } |
172 | |
8eebd221 |
173 | sk_set_frozen(ps->sub_socket, is_frozen); |
174 | } |
175 | |
176 | static char * sk_proxy_socket_error (Socket s) |
177 | { |
178 | Proxy_Socket ps = (Proxy_Socket) s; |
179 | if (ps->error != NULL || ps->sub_socket == NULL) { |
180 | return ps->error; |
181 | } |
182 | return sk_socket_error(ps->sub_socket); |
183 | } |
184 | |
185 | /* basic proxy plug functions */ |
186 | |
187 | static int plug_proxy_closing (Plug p, char *error_msg, |
188 | int error_code, int calling_back) |
189 | { |
190 | Proxy_Plug pp = (Proxy_Plug) p; |
191 | Proxy_Socket ps = pp->proxy_socket; |
192 | |
8eebd221 |
193 | if (ps->state != PROXY_STATE_ACTIVE) { |
194 | ps->closing_error_msg = error_msg; |
195 | ps->closing_error_code = error_code; |
196 | ps->closing_calling_back = calling_back; |
197 | return ps->negotiate(ps, PROXY_CHANGE_CLOSING); |
198 | } |
199 | return plug_closing(ps->plug, error_msg, |
200 | error_code, calling_back); |
201 | } |
202 | |
203 | static int plug_proxy_receive (Plug p, int urgent, char *data, int len) |
204 | { |
205 | Proxy_Plug pp = (Proxy_Plug) p; |
206 | Proxy_Socket ps = pp->proxy_socket; |
207 | |
8eebd221 |
208 | if (ps->state != PROXY_STATE_ACTIVE) { |
209 | /* we will lose the urgentness of this data, but since most, |
210 | * if not all, of this data will be consumed by the negotiation |
211 | * process, hopefully it won't affect the protocol above us |
212 | */ |
213 | bufchain_add(&ps->pending_input_data, data, len); |
214 | ps->receive_urgent = urgent; |
215 | ps->receive_data = data; |
216 | ps->receive_len = len; |
217 | return ps->negotiate(ps, PROXY_CHANGE_RECEIVE); |
218 | } |
219 | return plug_receive(ps->plug, urgent, data, len); |
220 | } |
221 | |
222 | static void plug_proxy_sent (Plug p, int bufsize) |
223 | { |
224 | Proxy_Plug pp = (Proxy_Plug) p; |
225 | Proxy_Socket ps = pp->proxy_socket; |
226 | |
8eebd221 |
227 | if (ps->state != PROXY_STATE_ACTIVE) { |
228 | ps->sent_bufsize = bufsize; |
229 | ps->negotiate(ps, PROXY_CHANGE_SENT); |
230 | return; |
231 | } |
232 | plug_sent(ps->plug, bufsize); |
233 | } |
234 | |
235 | static int plug_proxy_accepting (Plug p, void *sock) |
236 | { |
237 | Proxy_Plug pp = (Proxy_Plug) p; |
238 | Proxy_Socket ps = pp->proxy_socket; |
239 | |
8eebd221 |
240 | if (ps->state != PROXY_STATE_ACTIVE) { |
241 | ps->accepting_sock = sock; |
242 | return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING); |
243 | } |
244 | return plug_accepting(ps->plug, sock); |
245 | } |
246 | |
b7a189f3 |
247 | /* |
248 | * This function can accept a NULL pointer as `addr', in which case |
249 | * it will only check the host name. |
250 | */ |
e8fa8f62 |
251 | static int proxy_for_destination (SockAddr addr, char *hostname, int port, |
252 | const Config *cfg) |
8eebd221 |
253 | { |
254 | int s = 0, e = 0; |
255 | char hostip[64]; |
256 | int hostip_len, hostname_len; |
e8fa8f62 |
257 | const char *exclude_list; |
8eebd221 |
258 | |
b804e1e5 |
259 | /* |
260 | * Check the host name and IP against the hard-coded |
261 | * representations of `localhost'. |
262 | */ |
e8fa8f62 |
263 | if (!cfg->even_proxy_localhost && |
b7a189f3 |
264 | (sk_hostname_is_local(hostname) || |
265 | (addr && sk_address_is_local(addr)))) |
b804e1e5 |
266 | return 0; /* do not proxy */ |
267 | |
8eebd221 |
268 | /* we want a string representation of the IP address for comparisons */ |
b7a189f3 |
269 | if (addr) { |
270 | sk_getaddr(addr, hostip, 64); |
271 | hostip_len = strlen(hostip); |
272 | } |
8eebd221 |
273 | |
8eebd221 |
274 | hostname_len = strlen(hostname); |
275 | |
e8fa8f62 |
276 | exclude_list = cfg->proxy_exclude_list; |
8eebd221 |
277 | |
278 | /* now parse the exclude list, and see if either our IP |
279 | * or hostname matches anything in it. |
280 | */ |
281 | |
282 | while (exclude_list[s]) { |
283 | while (exclude_list[s] && |
e93ed432 |
284 | (isspace((unsigned char)exclude_list[s]) || |
8eebd221 |
285 | exclude_list[s] == ',')) s++; |
286 | |
287 | if (!exclude_list[s]) break; |
288 | |
289 | e = s; |
290 | |
291 | while (exclude_list[e] && |
e93ed432 |
292 | (isalnum((unsigned char)exclude_list[e]) || |
8eebd221 |
293 | exclude_list[e] == '-' || |
294 | exclude_list[e] == '.' || |
295 | exclude_list[e] == '*')) e++; |
296 | |
297 | if (exclude_list[s] == '*') { |
298 | /* wildcard at beginning of entry */ |
299 | |
b7a189f3 |
300 | if ((addr && strnicmp(hostip + hostip_len - (e - s - 1), |
301 | exclude_list + s + 1, e - s - 1) == 0) || |
8eebd221 |
302 | strnicmp(hostname + hostname_len - (e - s - 1), |
303 | exclude_list + s + 1, e - s - 1) == 0) |
304 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
305 | |
306 | } else if (exclude_list[e-1] == '*') { |
307 | /* wildcard at end of entry */ |
308 | |
b7a189f3 |
309 | if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) || |
8eebd221 |
310 | strnicmp(hostname, exclude_list + s, e - s - 1) == 0) |
311 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
312 | |
313 | } else { |
314 | /* no wildcard at either end, so let's try an absolute |
315 | * match (ie. a specific IP) |
316 | */ |
317 | |
b7a189f3 |
318 | if (addr && stricmp(hostip, exclude_list + s) == 0) |
8eebd221 |
319 | return 0; /* IP/hostname excluded. do not use proxy. */ |
320 | if (stricmp(hostname, exclude_list + s) == 0) |
321 | return 0; /* IP/hostname excluded. do not use proxy. */ |
322 | } |
323 | |
324 | s = e; |
1b08e5d7 |
325 | |
326 | /* Make sure we really have reached the next comma or end-of-string */ |
327 | while (exclude_list[s] && |
e93ed432 |
328 | !isspace((unsigned char)exclude_list[s]) && |
1b08e5d7 |
329 | exclude_list[s] != ',') s++; |
8eebd221 |
330 | } |
331 | |
332 | /* no matches in the exclude list, so use the proxy */ |
333 | return 1; |
334 | } |
335 | |
e8fa8f62 |
336 | SockAddr name_lookup(char *host, int port, char **canonicalname, |
337 | const Config *cfg) |
b7a189f3 |
338 | { |
e8fa8f62 |
339 | if (cfg->proxy_type != PROXY_NONE && |
340 | do_proxy_dns(cfg) && |
341 | proxy_for_destination(NULL, host, port, cfg)) { |
b7a189f3 |
342 | *canonicalname = dupstr(host); |
343 | return sk_nonamelookup(host); |
344 | } |
345 | |
346 | return sk_namelookup(host, canonicalname); |
347 | } |
348 | |
8eebd221 |
349 | Socket new_connection(SockAddr addr, char *hostname, |
350 | int port, int privport, |
e8fa8f62 |
351 | int oobinline, int nodelay, Plug plug, |
352 | const Config *cfg) |
8eebd221 |
353 | { |
7b6c9b99 |
354 | static const struct socket_function_table socket_fn_table = { |
8eebd221 |
355 | sk_proxy_plug, |
356 | sk_proxy_close, |
357 | sk_proxy_write, |
358 | sk_proxy_write_oob, |
359 | sk_proxy_flush, |
360 | sk_proxy_set_private_ptr, |
361 | sk_proxy_get_private_ptr, |
362 | sk_proxy_set_frozen, |
363 | sk_proxy_socket_error |
364 | }; |
365 | |
7b6c9b99 |
366 | static const struct plug_function_table plug_fn_table = { |
8eebd221 |
367 | plug_proxy_closing, |
368 | plug_proxy_receive, |
369 | plug_proxy_sent, |
370 | plug_proxy_accepting |
371 | }; |
372 | |
e8fa8f62 |
373 | if (cfg->proxy_type != PROXY_NONE && |
374 | proxy_for_destination(addr, hostname, port, cfg)) |
8eebd221 |
375 | { |
376 | Proxy_Socket ret; |
377 | Proxy_Plug pplug; |
378 | SockAddr proxy_addr; |
42389a9e |
379 | char *proxy_canonical_name, *err; |
8eebd221 |
380 | |
3d88e64d |
381 | ret = snew(struct Socket_proxy_tag); |
8eebd221 |
382 | ret->fn = &socket_fn_table; |
e8fa8f62 |
383 | ret->cfg = *cfg; /* STRUCTURE COPY */ |
8eebd221 |
384 | ret->plug = plug; |
385 | ret->remote_addr = addr; |
386 | ret->remote_port = port; |
387 | |
65c78e88 |
388 | ret->error = NULL; |
389 | ret->pending_flush = 0; |
390 | ret->freeze = 0; |
391 | |
8eebd221 |
392 | bufchain_init(&ret->pending_input_data); |
393 | bufchain_init(&ret->pending_output_data); |
394 | bufchain_init(&ret->pending_oob_output_data); |
395 | |
8eebd221 |
396 | ret->sub_socket = NULL; |
397 | ret->state = PROXY_STATE_NEW; |
2d129d8e |
398 | ret->negotiate = NULL; |
399 | |
e8fa8f62 |
400 | if (cfg->proxy_type == PROXY_HTTP) { |
8eebd221 |
401 | ret->negotiate = proxy_http_negotiate; |
e8fa8f62 |
402 | } else if (cfg->proxy_type == PROXY_SOCKS) { |
403 | if (cfg->proxy_socks_version == 4) |
6971bbe7 |
404 | ret->negotiate = proxy_socks4_negotiate; |
405 | else |
406 | ret->negotiate = proxy_socks5_negotiate; |
e8fa8f62 |
407 | } else if (cfg->proxy_type == PROXY_TELNET) { |
8eebd221 |
408 | ret->negotiate = proxy_telnet_negotiate; |
409 | } else { |
7983f47e |
410 | ret->error = "Proxy error: Unknown proxy method"; |
8eebd221 |
411 | return (Socket) ret; |
412 | } |
413 | |
414 | /* create the proxy plug to map calls from the actual |
415 | * socket into our proxy socket layer */ |
3d88e64d |
416 | pplug = snew(struct Plug_proxy_tag); |
8eebd221 |
417 | pplug->fn = &plug_fn_table; |
418 | pplug->proxy_socket = ret; |
419 | |
420 | /* look-up proxy */ |
e8fa8f62 |
421 | proxy_addr = sk_namelookup(cfg->proxy_host, |
8eebd221 |
422 | &proxy_canonical_name); |
616a115c |
423 | if ((err = sk_addr_error(proxy_addr)) != NULL) { |
42389a9e |
424 | ret->error = "Proxy error: Unable to resolve proxy host name"; |
425 | return (Socket)ret; |
426 | } |
8eebd221 |
427 | sfree(proxy_canonical_name); |
428 | |
429 | /* create the actual socket we will be using, |
430 | * connected to our proxy server and port. |
431 | */ |
e8fa8f62 |
432 | ret->sub_socket = sk_new(proxy_addr, cfg->proxy_port, |
8eebd221 |
433 | privport, oobinline, |
434 | nodelay, (Plug) pplug); |
435 | if (sk_socket_error(ret->sub_socket) != NULL) |
436 | return (Socket) ret; |
437 | |
438 | sk_addr_free(proxy_addr); |
439 | |
440 | /* start the proxy negotiation process... */ |
441 | sk_set_frozen(ret->sub_socket, 0); |
442 | ret->negotiate(ret, PROXY_CHANGE_NEW); |
443 | |
444 | return (Socket) ret; |
445 | } |
446 | |
447 | /* no proxy, so just return the direct socket */ |
448 | return sk_new(addr, port, privport, oobinline, nodelay, plug); |
449 | } |
450 | |
e8fa8f62 |
451 | Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only, |
452 | const Config *cfg) |
8eebd221 |
453 | { |
454 | /* TODO: SOCKS (and potentially others) support inbound |
455 | * TODO: connections via the proxy. support them. |
456 | */ |
457 | |
6ee9b735 |
458 | return sk_newlistener(srcaddr, port, plug, local_host_only); |
8eebd221 |
459 | } |
460 | |
461 | /* ---------------------------------------------------------------------- |
462 | * HTTP CONNECT proxy type. |
463 | */ |
464 | |
465 | static int get_line_end (char * data, int len) |
466 | { |
467 | int off = 0; |
468 | |
469 | while (off < len) |
470 | { |
471 | if (data[off] == '\n') { |
472 | /* we have a newline */ |
473 | off++; |
474 | |
475 | /* is that the only thing on this line? */ |
476 | if (off <= 2) return off; |
477 | |
478 | /* if not, then there is the possibility that this header |
479 | * continues onto the next line, if it starts with a space |
480 | * or a tab. |
481 | */ |
482 | |
483 | if (off + 1 < len && |
484 | data[off+1] != ' ' && |
485 | data[off+1] != '\t') return off; |
486 | |
487 | /* the line does continue, so we have to keep going |
488 | * until we see an the header's "real" end of line. |
489 | */ |
490 | off++; |
491 | } |
492 | |
493 | off++; |
494 | } |
495 | |
496 | return -1; |
497 | } |
498 | |
499 | int proxy_http_negotiate (Proxy_Socket p, int change) |
500 | { |
501 | if (p->state == PROXY_STATE_NEW) { |
502 | /* we are just beginning the proxy negotiate process, |
503 | * so we'll send off the initial bits of the request. |
504 | * for this proxy method, it's just a simple HTTP |
505 | * request |
506 | */ |
b7a189f3 |
507 | char *buf, dest[512]; |
8eebd221 |
508 | |
b7a189f3 |
509 | sk_getaddr(p->remote_addr, dest, lenof(dest)); |
8eebd221 |
510 | |
57356d63 |
511 | buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n", |
512 | dest, p->remote_port, dest, p->remote_port); |
8eebd221 |
513 | sk_write(p->sub_socket, buf, strlen(buf)); |
57356d63 |
514 | sfree(buf); |
8eebd221 |
515 | |
e8fa8f62 |
516 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
517 | char buf[sizeof(p->cfg.proxy_username)+sizeof(p->cfg.proxy_password)]; |
1549e076 |
518 | char buf2[sizeof(buf)*4/3 + 100]; |
519 | int i, j, len; |
e8fa8f62 |
520 | sprintf(buf, "%s:%s", p->cfg.proxy_username, p->cfg.proxy_password); |
1549e076 |
521 | len = strlen(buf); |
6c434e1f |
522 | sprintf(buf2, "Proxy-Authorization: Basic "); |
1549e076 |
523 | for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4) |
616a115c |
524 | base64_encode_atom((unsigned char *)(buf+i), |
525 | (len-i > 3 ? 3 : len-i), buf2+j); |
1549e076 |
526 | strcpy(buf2+j, "\r\n"); |
527 | sk_write(p->sub_socket, buf2, strlen(buf2)); |
528 | } |
529 | |
9ddf18a4 |
530 | sk_write(p->sub_socket, "\r\n", 2); |
1549e076 |
531 | |
8eebd221 |
532 | p->state = 1; |
8eebd221 |
533 | return 0; |
534 | } |
535 | |
536 | if (change == PROXY_CHANGE_CLOSING) { |
537 | /* if our proxy negotiation process involves closing and opening |
538 | * new sockets, then we would want to intercept this closing |
539 | * callback when we were expecting it. if we aren't anticipating |
540 | * a socket close, then some error must have occurred. we'll |
541 | * just pass those errors up to the backend. |
542 | */ |
543 | return plug_closing(p->plug, p->closing_error_msg, |
544 | p->closing_error_code, |
545 | p->closing_calling_back); |
546 | } |
547 | |
548 | if (change == PROXY_CHANGE_SENT) { |
549 | /* some (or all) of what we wrote to the proxy was sent. |
550 | * we don't do anything new, however, until we receive the |
551 | * proxy's response. we might want to set a timer so we can |
552 | * timeout the proxy negotiation after a while... |
553 | */ |
554 | return 0; |
555 | } |
556 | |
557 | if (change == PROXY_CHANGE_ACCEPTING) { |
558 | /* we should _never_ see this, as we are using our socket to |
559 | * connect to a proxy, not accepting inbound connections. |
560 | * what should we do? close the socket with an appropriate |
561 | * error message? |
562 | */ |
563 | return plug_accepting(p->plug, p->accepting_sock); |
564 | } |
565 | |
566 | if (change == PROXY_CHANGE_RECEIVE) { |
567 | /* we have received data from the underlying socket, which |
568 | * we'll need to parse, process, and respond to appropriately. |
569 | */ |
570 | |
7983f47e |
571 | char *data, *datap; |
8eebd221 |
572 | int len; |
573 | int eol; |
574 | |
575 | if (p->state == 1) { |
576 | |
577 | int min_ver, maj_ver, status; |
578 | |
579 | /* get the status line */ |
7983f47e |
580 | len = bufchain_size(&p->pending_input_data); |
581 | assert(len > 0); /* or we wouldn't be here */ |
3d88e64d |
582 | data = snewn(len, char); |
7983f47e |
583 | bufchain_fetch(&p->pending_input_data, data, len); |
584 | |
8eebd221 |
585 | eol = get_line_end(data, len); |
7983f47e |
586 | if (eol < 0) { |
587 | sfree(data); |
588 | return 1; |
589 | } |
8eebd221 |
590 | |
7983f47e |
591 | status = -1; |
592 | /* We can't rely on whether the %n incremented the sscanf return */ |
593 | if (sscanf((char *)data, "HTTP/%i.%i %n", |
594 | &maj_ver, &min_ver, &status) < 2 || status == -1) { |
595 | plug_closing(p->plug, "Proxy error: HTTP response was absent", |
596 | PROXY_ERROR_GENERAL, 0); |
597 | sfree(data); |
598 | return 1; |
599 | } |
8eebd221 |
600 | |
601 | /* remove the status line from the input buffer. */ |
602 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
603 | if (data[status] != '2') { |
8eebd221 |
604 | /* error */ |
57356d63 |
605 | char *buf; |
7983f47e |
606 | data[eol] = '\0'; |
607 | while (eol > status && |
608 | (data[eol-1] == '\r' || data[eol-1] == '\n')) |
609 | data[--eol] = '\0'; |
57356d63 |
610 | buf = dupprintf("Proxy error: %s", data+status); |
7983f47e |
611 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
57356d63 |
612 | sfree(buf); |
7983f47e |
613 | sfree(data); |
8eebd221 |
614 | return 1; |
615 | } |
616 | |
7983f47e |
617 | sfree(data); |
618 | |
8eebd221 |
619 | p->state = 2; |
620 | } |
621 | |
622 | if (p->state == 2) { |
623 | |
624 | /* get headers. we're done when we get a |
625 | * header of length 2, (ie. just "\r\n") |
626 | */ |
627 | |
7983f47e |
628 | len = bufchain_size(&p->pending_input_data); |
629 | assert(len > 0); /* or we wouldn't be here */ |
3d88e64d |
630 | data = snewn(len, char); |
7983f47e |
631 | datap = data; |
632 | bufchain_fetch(&p->pending_input_data, data, len); |
633 | |
634 | eol = get_line_end(datap, len); |
635 | if (eol < 0) { |
636 | sfree(data); |
637 | return 1; |
638 | } |
8eebd221 |
639 | while (eol > 2) |
640 | { |
8eebd221 |
641 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
642 | datap += eol; |
9ddf18a4 |
643 | len -= eol; |
7983f47e |
644 | eol = get_line_end(datap, len); |
8eebd221 |
645 | } |
646 | |
647 | if (eol == 2) { |
648 | /* we're done */ |
649 | bufchain_consume(&p->pending_input_data, 2); |
650 | proxy_activate(p); |
651 | /* proxy activate will have dealt with |
652 | * whatever is left of the buffer */ |
7983f47e |
653 | sfree(data); |
8eebd221 |
654 | return 1; |
655 | } |
656 | |
7983f47e |
657 | sfree(data); |
8eebd221 |
658 | return 1; |
659 | } |
660 | } |
661 | |
7983f47e |
662 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
8eebd221 |
663 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
664 | return 1; |
8eebd221 |
665 | } |
666 | |
667 | /* ---------------------------------------------------------------------- |
6971bbe7 |
668 | * SOCKS proxy type. |
8eebd221 |
669 | */ |
670 | |
6971bbe7 |
671 | /* SOCKS version 4 */ |
672 | int proxy_socks4_negotiate (Proxy_Socket p, int change) |
8eebd221 |
673 | { |
6971bbe7 |
674 | if (p->state == PROXY_CHANGE_NEW) { |
675 | |
676 | /* request format: |
677 | * version number (1 byte) = 4 |
678 | * command code (1 byte) |
679 | * 1 = CONNECT |
680 | * 2 = BIND |
681 | * dest. port (2 bytes) [network order] |
682 | * dest. address (4 bytes) |
683 | * user ID (variable length, null terminated string) |
684 | */ |
685 | |
b7a189f3 |
686 | int length, type, namelen; |
687 | char *command, addr[4], hostname[512]; |
6971bbe7 |
688 | |
b7a189f3 |
689 | type = sk_addrtype(p->remote_addr); |
690 | if (type == ADDRTYPE_IPV6) { |
7983f47e |
691 | plug_closing(p->plug, "Proxy error: SOCKS version 4 does" |
692 | " not support IPv6", PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
693 | return 1; |
b7a189f3 |
694 | } else if (type == ADDRTYPE_IPV4) { |
695 | namelen = 0; |
696 | sk_addrcopy(p->remote_addr, addr); |
697 | } else { /* type == ADDRTYPE_NAME */ |
698 | sk_getaddr(p->remote_addr, hostname, lenof(hostname)); |
699 | namelen = strlen(hostname) + 1; /* include the NUL */ |
700 | addr[0] = addr[1] = addr[2] = 0; |
701 | addr[3] = 1; |
6971bbe7 |
702 | } |
703 | |
e8fa8f62 |
704 | length = strlen(p->cfg.proxy_username) + namelen + 9; |
3d88e64d |
705 | command = snewn(length, char); |
e8fa8f62 |
706 | strcpy(command + 8, p->cfg.proxy_username); |
6971bbe7 |
707 | |
708 | command[0] = 4; /* version 4 */ |
709 | command[1] = 1; /* CONNECT command */ |
710 | |
711 | /* port */ |
712 | command[2] = (char) (p->remote_port >> 8) & 0xff; |
713 | command[3] = (char) p->remote_port & 0xff; |
714 | |
715 | /* address */ |
b7a189f3 |
716 | memcpy(command + 4, addr, 4); |
717 | |
718 | /* hostname */ |
e8fa8f62 |
719 | memcpy(command + 8 + strlen(p->cfg.proxy_username) + 1, |
b7a189f3 |
720 | hostname, namelen); |
6971bbe7 |
721 | |
722 | sk_write(p->sub_socket, command, length); |
de9aaffb |
723 | sfree(command); |
6971bbe7 |
724 | |
725 | p->state = 1; |
726 | return 0; |
727 | } |
728 | |
729 | if (change == PROXY_CHANGE_CLOSING) { |
730 | /* if our proxy negotiation process involves closing and opening |
731 | * new sockets, then we would want to intercept this closing |
732 | * callback when we were expecting it. if we aren't anticipating |
733 | * a socket close, then some error must have occurred. we'll |
734 | * just pass those errors up to the backend. |
735 | */ |
736 | return plug_closing(p->plug, p->closing_error_msg, |
737 | p->closing_error_code, |
738 | p->closing_calling_back); |
739 | } |
740 | |
741 | if (change == PROXY_CHANGE_SENT) { |
742 | /* some (or all) of what we wrote to the proxy was sent. |
743 | * we don't do anything new, however, until we receive the |
744 | * proxy's response. we might want to set a timer so we can |
745 | * timeout the proxy negotiation after a while... |
746 | */ |
747 | return 0; |
748 | } |
749 | |
750 | if (change == PROXY_CHANGE_ACCEPTING) { |
751 | /* we should _never_ see this, as we are using our socket to |
752 | * connect to a proxy, not accepting inbound connections. |
753 | * what should we do? close the socket with an appropriate |
754 | * error message? |
755 | */ |
756 | return plug_accepting(p->plug, p->accepting_sock); |
757 | } |
758 | |
759 | if (change == PROXY_CHANGE_RECEIVE) { |
760 | /* we have received data from the underlying socket, which |
761 | * we'll need to parse, process, and respond to appropriately. |
762 | */ |
763 | |
764 | if (p->state == 1) { |
765 | /* response format: |
766 | * version number (1 byte) = 4 |
767 | * reply code (1 byte) |
768 | * 90 = request granted |
769 | * 91 = request rejected or failed |
770 | * 92 = request rejected due to lack of IDENTD on client |
771 | * 93 = request rejected due to difference in user ID |
772 | * (what we sent vs. what IDENTD said) |
773 | * dest. port (2 bytes) |
774 | * dest. address (4 bytes) |
775 | */ |
776 | |
7983f47e |
777 | char data[8]; |
6971bbe7 |
778 | |
7983f47e |
779 | if (bufchain_size(&p->pending_input_data) < 8) |
780 | return 1; /* not got anything yet */ |
781 | |
6971bbe7 |
782 | /* get the response */ |
7983f47e |
783 | bufchain_fetch(&p->pending_input_data, data, 8); |
6971bbe7 |
784 | |
785 | if (data[0] != 0) { |
7983f47e |
786 | plug_closing(p->plug, "Proxy error: SOCKS proxy responded with " |
6971bbe7 |
787 | "unexpected reply code version", |
788 | PROXY_ERROR_GENERAL, 0); |
789 | return 1; |
790 | } |
791 | |
792 | if (data[1] != 90) { |
793 | |
794 | switch (data[1]) { |
795 | case 92: |
7983f47e |
796 | plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client", |
6971bbe7 |
797 | PROXY_ERROR_GENERAL, 0); |
798 | break; |
799 | case 93: |
7983f47e |
800 | plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree", |
6971bbe7 |
801 | PROXY_ERROR_GENERAL, 0); |
802 | break; |
803 | case 91: |
804 | default: |
7983f47e |
805 | plug_closing(p->plug, "Proxy error: Error while communicating with proxy", |
6971bbe7 |
806 | PROXY_ERROR_GENERAL, 0); |
807 | break; |
808 | } |
809 | |
810 | return 1; |
811 | } |
7983f47e |
812 | bufchain_consume(&p->pending_input_data, 8); |
6971bbe7 |
813 | |
814 | /* we're done */ |
815 | proxy_activate(p); |
816 | /* proxy activate will have dealt with |
817 | * whatever is left of the buffer */ |
818 | return 1; |
819 | } |
820 | } |
821 | |
7983f47e |
822 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
6971bbe7 |
823 | PROXY_ERROR_UNEXPECTED, 0); |
824 | return 1; |
825 | } |
826 | |
827 | /* SOCKS version 5 */ |
828 | int proxy_socks5_negotiate (Proxy_Socket p, int change) |
829 | { |
830 | if (p->state == PROXY_CHANGE_NEW) { |
831 | |
832 | /* initial command: |
833 | * version number (1 byte) = 5 |
834 | * number of available authentication methods (1 byte) |
835 | * available authentication methods (1 byte * previous value) |
836 | * authentication methods: |
837 | * 0x00 = no authentication |
838 | * 0x01 = GSSAPI |
839 | * 0x02 = username/password |
840 | * 0x03 = CHAP |
841 | */ |
842 | |
aab91a3e |
843 | char command[4]; |
844 | int len; |
6971bbe7 |
845 | |
846 | command[0] = 5; /* version 5 */ |
e8fa8f62 |
847 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
aab91a3e |
848 | command[1] = 2; /* two methods supported: */ |
849 | command[2] = 0x00; /* no authentication */ |
850 | command[3] = 0x02; /* username/password */ |
851 | len = 4; |
852 | } else { |
853 | command[1] = 1; /* one methods supported: */ |
854 | command[2] = 0x00; /* no authentication */ |
855 | len = 3; |
856 | } |
6971bbe7 |
857 | |
aab91a3e |
858 | sk_write(p->sub_socket, command, len); |
6971bbe7 |
859 | |
860 | p->state = 1; |
861 | return 0; |
862 | } |
863 | |
864 | if (change == PROXY_CHANGE_CLOSING) { |
865 | /* if our proxy negotiation process involves closing and opening |
866 | * new sockets, then we would want to intercept this closing |
867 | * callback when we were expecting it. if we aren't anticipating |
868 | * a socket close, then some error must have occurred. we'll |
869 | * just pass those errors up to the backend. |
870 | */ |
871 | return plug_closing(p->plug, p->closing_error_msg, |
872 | p->closing_error_code, |
873 | p->closing_calling_back); |
874 | } |
875 | |
876 | if (change == PROXY_CHANGE_SENT) { |
877 | /* some (or all) of what we wrote to the proxy was sent. |
878 | * we don't do anything new, however, until we receive the |
879 | * proxy's response. we might want to set a timer so we can |
880 | * timeout the proxy negotiation after a while... |
881 | */ |
882 | return 0; |
883 | } |
884 | |
885 | if (change == PROXY_CHANGE_ACCEPTING) { |
886 | /* we should _never_ see this, as we are using our socket to |
887 | * connect to a proxy, not accepting inbound connections. |
888 | * what should we do? close the socket with an appropriate |
889 | * error message? |
890 | */ |
891 | return plug_accepting(p->plug, p->accepting_sock); |
892 | } |
893 | |
894 | if (change == PROXY_CHANGE_RECEIVE) { |
895 | /* we have received data from the underlying socket, which |
896 | * we'll need to parse, process, and respond to appropriately. |
897 | */ |
898 | |
6971bbe7 |
899 | if (p->state == 1) { |
900 | |
901 | /* initial response: |
902 | * version number (1 byte) = 5 |
903 | * authentication method (1 byte) |
904 | * authentication methods: |
905 | * 0x00 = no authentication |
906 | * 0x01 = GSSAPI |
907 | * 0x02 = username/password |
908 | * 0x03 = CHAP |
909 | * 0xff = no acceptable methods |
910 | */ |
7983f47e |
911 | char data[2]; |
912 | |
913 | if (bufchain_size(&p->pending_input_data) < 2) |
914 | return 1; /* not got anything yet */ |
6971bbe7 |
915 | |
916 | /* get the response */ |
7983f47e |
917 | bufchain_fetch(&p->pending_input_data, data, 2); |
6971bbe7 |
918 | |
919 | if (data[0] != 5) { |
7983f47e |
920 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version", |
6971bbe7 |
921 | PROXY_ERROR_GENERAL, 0); |
922 | return 1; |
923 | } |
924 | |
925 | if (data[1] == 0x00) p->state = 2; /* no authentication needed */ |
926 | else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */ |
927 | else if (data[1] == 0x02) p->state = 5; /* username/password authentication */ |
928 | else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */ |
929 | else { |
7983f47e |
930 | plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication", |
6971bbe7 |
931 | PROXY_ERROR_GENERAL, 0); |
932 | return 1; |
933 | } |
aab91a3e |
934 | bufchain_consume(&p->pending_input_data, 2); |
935 | } |
936 | |
937 | if (p->state == 7) { |
938 | |
939 | /* password authentication reply format: |
940 | * version number (1 bytes) = 1 |
941 | * reply code (1 byte) |
942 | * 0 = succeeded |
943 | * >0 = failed |
944 | */ |
7983f47e |
945 | char data[2]; |
946 | |
947 | if (bufchain_size(&p->pending_input_data) < 2) |
948 | return 1; /* not got anything yet */ |
aab91a3e |
949 | |
950 | /* get the response */ |
7983f47e |
951 | bufchain_fetch(&p->pending_input_data, data, 2); |
aab91a3e |
952 | |
953 | if (data[0] != 1) { |
7983f47e |
954 | plug_closing(p->plug, "Proxy error: SOCKS password " |
955 | "subnegotiation contained wrong version number", |
aab91a3e |
956 | PROXY_ERROR_GENERAL, 0); |
957 | return 1; |
958 | } |
959 | |
960 | if (data[1] != 0) { |
961 | |
7983f47e |
962 | plug_closing(p->plug, "Proxy error: SOCKS proxy refused" |
963 | " password authentication", |
aab91a3e |
964 | PROXY_ERROR_GENERAL, 0); |
965 | return 1; |
966 | } |
967 | |
968 | bufchain_consume(&p->pending_input_data, 2); |
969 | p->state = 2; /* now proceed as authenticated */ |
6971bbe7 |
970 | } |
971 | |
972 | if (p->state == 2) { |
973 | |
974 | /* request format: |
975 | * version number (1 byte) = 5 |
976 | * command code (1 byte) |
977 | * 1 = CONNECT |
978 | * 2 = BIND |
979 | * 3 = UDP ASSOCIATE |
980 | * reserved (1 byte) = 0x00 |
981 | * address type (1 byte) |
982 | * 1 = IPv4 |
983 | * 3 = domainname (first byte has length, no terminating null) |
984 | * 4 = IPv6 |
985 | * dest. address (variable) |
986 | * dest. port (2 bytes) [network order] |
987 | */ |
988 | |
b7a189f3 |
989 | char command[512]; |
6971bbe7 |
990 | int len; |
b7a189f3 |
991 | int type; |
6971bbe7 |
992 | |
b7a189f3 |
993 | type = sk_addrtype(p->remote_addr); |
994 | if (type == ADDRTYPE_IPV4) { |
995 | len = 10; /* 4 hdr + 4 addr + 2 trailer */ |
6971bbe7 |
996 | command[3] = 1; /* IPv4 */ |
b7a189f3 |
997 | sk_addrcopy(p->remote_addr, command+4); |
998 | } else if (type == ADDRTYPE_IPV6) { |
999 | len = 22; /* 4 hdr + 16 addr + 2 trailer */ |
6971bbe7 |
1000 | command[3] = 4; /* IPv6 */ |
b7a189f3 |
1001 | sk_addrcopy(p->remote_addr, command+4); |
1002 | } else if (type == ADDRTYPE_NAME) { |
1003 | command[3] = 3; |
1004 | sk_getaddr(p->remote_addr, command+5, 256); |
1005 | command[4] = strlen(command+5); |
1006 | len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */ |
6971bbe7 |
1007 | } |
1008 | |
1009 | command[0] = 5; /* version 5 */ |
1010 | command[1] = 1; /* CONNECT command */ |
1011 | command[2] = 0x00; |
1012 | |
6971bbe7 |
1013 | /* port */ |
1014 | command[len-2] = (char) (p->remote_port >> 8) & 0xff; |
1015 | command[len-1] = (char) p->remote_port & 0xff; |
1016 | |
1017 | sk_write(p->sub_socket, command, len); |
1018 | |
1019 | p->state = 3; |
1020 | return 1; |
1021 | } |
1022 | |
1023 | if (p->state == 3) { |
1024 | |
1025 | /* reply format: |
1026 | * version number (1 bytes) = 5 |
1027 | * reply code (1 byte) |
1028 | * 0 = succeeded |
1029 | * 1 = general SOCKS server failure |
1030 | * 2 = connection not allowed by ruleset |
1031 | * 3 = network unreachable |
1032 | * 4 = host unreachable |
1033 | * 5 = connection refused |
1034 | * 6 = TTL expired |
1035 | * 7 = command not supported |
1036 | * 8 = address type not supported |
1037 | * reserved (1 byte) = x00 |
1038 | * address type (1 byte) |
1039 | * 1 = IPv4 |
1040 | * 3 = domainname (first byte has length, no terminating null) |
1041 | * 4 = IPv6 |
1042 | * server bound address (variable) |
1043 | * server bound port (2 bytes) [network order] |
1044 | */ |
7983f47e |
1045 | char data[5]; |
1046 | int len; |
1047 | |
1048 | /* First 5 bytes of packet are enough to tell its length. */ |
1049 | if (bufchain_size(&p->pending_input_data) < 5) |
1050 | return 1; /* not got anything yet */ |
6971bbe7 |
1051 | |
1052 | /* get the response */ |
7983f47e |
1053 | bufchain_fetch(&p->pending_input_data, data, 5); |
6971bbe7 |
1054 | |
1055 | if (data[0] != 5) { |
7983f47e |
1056 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number", |
6971bbe7 |
1057 | PROXY_ERROR_GENERAL, 0); |
1058 | return 1; |
1059 | } |
1060 | |
1061 | if (data[1] != 0) { |
7983f47e |
1062 | char buf[256]; |
1063 | |
1064 | strcpy(buf, "Proxy error: "); |
6971bbe7 |
1065 | |
1066 | switch (data[1]) { |
7983f47e |
1067 | case 1: strcat(buf, "General SOCKS server failure"); break; |
1068 | case 2: strcat(buf, "Connection not allowed by ruleset"); break; |
1069 | case 3: strcat(buf, "Network unreachable"); break; |
1070 | case 4: strcat(buf, "Host unreachable"); break; |
1071 | case 5: strcat(buf, "Connection refused"); break; |
1072 | case 6: strcat(buf, "TTL expired"); break; |
1073 | case 7: strcat(buf, "Command not supported"); break; |
1074 | case 8: strcat(buf, "Address type not supported"); break; |
1075 | default: sprintf(buf+strlen(buf), |
1076 | "Unrecognised SOCKS error code %d", |
1077 | data[1]); |
6971bbe7 |
1078 | break; |
1079 | } |
7983f47e |
1080 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
1081 | |
1082 | return 1; |
1083 | } |
6971bbe7 |
1084 | |
7983f47e |
1085 | /* |
1086 | * Eat the rest of the reply packet. |
1087 | */ |
1088 | len = 6; /* first 4 bytes, last 2 */ |
1089 | switch (data[3]) { |
1090 | case 1: len += 4; break; /* IPv4 address */ |
1091 | case 4: len += 16; break;/* IPv6 address */ |
1092 | case 3: len += (unsigned char)data[4]; break; /* domain name */ |
1093 | default: |
1094 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned " |
1095 | "unrecognised address format", |
1096 | PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
1097 | return 1; |
1098 | } |
7983f47e |
1099 | if (bufchain_size(&p->pending_input_data) < len) |
1100 | return 1; /* not got whole reply yet */ |
1101 | bufchain_consume(&p->pending_input_data, len); |
6971bbe7 |
1102 | |
1103 | /* we're done */ |
1104 | proxy_activate(p); |
6971bbe7 |
1105 | return 1; |
1106 | } |
1107 | |
1108 | if (p->state == 4) { |
1109 | /* TODO: Handle GSSAPI authentication */ |
2192a8e4 |
1110 | plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication", |
6971bbe7 |
1111 | PROXY_ERROR_GENERAL, 0); |
1112 | return 1; |
1113 | } |
1114 | |
1115 | if (p->state == 5) { |
e8fa8f62 |
1116 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
aab91a3e |
1117 | char userpwbuf[514]; |
1118 | int ulen, plen; |
e8fa8f62 |
1119 | ulen = strlen(p->cfg.proxy_username); |
aab91a3e |
1120 | if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1; |
e8fa8f62 |
1121 | plen = strlen(p->cfg.proxy_password); |
aab91a3e |
1122 | if (plen > 255) plen = 255; if (plen < 1) plen = 1; |
1123 | userpwbuf[0] = 1; /* version number of subnegotiation */ |
1124 | userpwbuf[1] = ulen; |
e8fa8f62 |
1125 | memcpy(userpwbuf+2, p->cfg.proxy_username, ulen); |
aab91a3e |
1126 | userpwbuf[ulen+2] = plen; |
e8fa8f62 |
1127 | memcpy(userpwbuf+ulen+3, p->cfg.proxy_password, plen); |
aab91a3e |
1128 | sk_write(p->sub_socket, userpwbuf, ulen + plen + 3); |
1129 | p->state = 7; |
1130 | } else |
2192a8e4 |
1131 | plug_closing(p->plug, "Proxy error: Server chose " |
aab91a3e |
1132 | "username/password authentication but we " |
1133 | "didn't offer it!", |
6971bbe7 |
1134 | PROXY_ERROR_GENERAL, 0); |
1135 | return 1; |
1136 | } |
1137 | |
1138 | if (p->state == 6) { |
1139 | /* TODO: Handle CHAP authentication */ |
2192a8e4 |
1140 | plug_closing(p->plug, "Proxy error: We don't support CHAP authentication", |
6971bbe7 |
1141 | PROXY_ERROR_GENERAL, 0); |
1142 | return 1; |
1143 | } |
aab91a3e |
1144 | |
6971bbe7 |
1145 | } |
1146 | |
2192a8e4 |
1147 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
6971bbe7 |
1148 | PROXY_ERROR_UNEXPECTED, 0); |
1149 | return 1; |
8eebd221 |
1150 | } |
1151 | |
1152 | /* ---------------------------------------------------------------------- |
0e8f4cda |
1153 | * `Telnet' proxy type. |
8eebd221 |
1154 | * |
1155 | * (This is for ad-hoc proxies where you connect to the proxy's |
1156 | * telnet port and send a command such as `connect host port'. The |
1157 | * command is configurable, since this proxy type is typically not |
1158 | * standardised or at all well-defined.) |
1159 | */ |
1160 | |
1161 | int proxy_telnet_negotiate (Proxy_Socket p, int change) |
1162 | { |
0e8f4cda |
1163 | if (p->state == PROXY_CHANGE_NEW) { |
1164 | |
1165 | int so = 0, eo = 0; |
1166 | |
1167 | /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, |
2d129d8e |
1168 | * %%, %host, %port, %user, and %pass |
0e8f4cda |
1169 | */ |
1170 | |
e8fa8f62 |
1171 | while (p->cfg.proxy_telnet_command[eo] != 0) { |
0e8f4cda |
1172 | |
1173 | /* scan forward until we hit end-of-line, |
1174 | * or an escape character (\ or %) */ |
e8fa8f62 |
1175 | while (p->cfg.proxy_telnet_command[eo] != 0 && |
1176 | p->cfg.proxy_telnet_command[eo] != '%' && |
1177 | p->cfg.proxy_telnet_command[eo] != '\\') eo++; |
0e8f4cda |
1178 | |
1179 | /* if we hit eol, break out of our escaping loop */ |
e8fa8f62 |
1180 | if (p->cfg.proxy_telnet_command[eo] == 0) break; |
0e8f4cda |
1181 | |
1182 | /* if there was any unescaped text before the escape |
1183 | * character, send that now */ |
1184 | if (eo != so) { |
1185 | sk_write(p->sub_socket, |
e8fa8f62 |
1186 | p->cfg.proxy_telnet_command + so, eo - so); |
0e8f4cda |
1187 | } |
1188 | |
1189 | so = eo++; |
1190 | |
1191 | /* if the escape character was the last character of |
1192 | * the line, we'll just stop and send it. */ |
e8fa8f62 |
1193 | if (p->cfg.proxy_telnet_command[eo] == 0) break; |
0e8f4cda |
1194 | |
e8fa8f62 |
1195 | if (p->cfg.proxy_telnet_command[so] == '\\') { |
0e8f4cda |
1196 | |
1197 | /* we recognize \\, \%, \r, \n, \t, \x??. |
1198 | * anything else, we just send unescaped (including the \). |
1199 | */ |
1200 | |
e8fa8f62 |
1201 | switch (p->cfg.proxy_telnet_command[eo]) { |
0e8f4cda |
1202 | |
1203 | case '\\': |
1204 | sk_write(p->sub_socket, "\\", 1); |
1205 | eo++; |
1206 | break; |
1207 | |
1208 | case '%': |
1209 | sk_write(p->sub_socket, "%%", 1); |
1210 | eo++; |
1211 | break; |
1212 | |
1213 | case 'r': |
1214 | sk_write(p->sub_socket, "\r", 1); |
1215 | eo++; |
1216 | break; |
1217 | |
1218 | case 'n': |
1219 | sk_write(p->sub_socket, "\n", 1); |
1220 | eo++; |
1221 | break; |
1222 | |
1223 | case 't': |
1224 | sk_write(p->sub_socket, "\t", 1); |
1225 | eo++; |
1226 | break; |
1227 | |
1228 | case 'x': |
1229 | case 'X': |
1230 | { |
1231 | /* escaped hexadecimal value (ie. \xff) */ |
1232 | unsigned char v = 0; |
1233 | int i = 0; |
1234 | |
1235 | for (;;) { |
1236 | eo++; |
e8fa8f62 |
1237 | if (p->cfg.proxy_telnet_command[eo] >= '0' && |
1238 | p->cfg.proxy_telnet_command[eo] <= '9') |
1239 | v += p->cfg.proxy_telnet_command[eo] - '0'; |
1240 | else if (p->cfg.proxy_telnet_command[eo] >= 'a' && |
1241 | p->cfg.proxy_telnet_command[eo] <= 'f') |
1242 | v += p->cfg.proxy_telnet_command[eo] - 'a' + 10; |
1243 | else if (p->cfg.proxy_telnet_command[eo] >= 'A' && |
1244 | p->cfg.proxy_telnet_command[eo] <= 'F') |
1245 | v += p->cfg.proxy_telnet_command[eo] - 'A' + 10; |
0e8f4cda |
1246 | else { |
1247 | /* non hex character, so we abort and just |
1248 | * send the whole thing unescaped (including \x) |
1249 | */ |
1250 | sk_write(p->sub_socket, "\\", 1); |
1251 | eo = so + 1; |
1252 | break; |
1253 | } |
1254 | |
1255 | /* we only extract two hex characters */ |
1256 | if (i == 1) { |
616a115c |
1257 | sk_write(p->sub_socket, (char *)&v, 1); |
0e8f4cda |
1258 | eo++; |
1259 | break; |
1260 | } |
1261 | |
1262 | i++; |
1263 | v <<= 4; |
1264 | } |
1265 | } |
1266 | break; |
1267 | |
1268 | default: |
1269 | sk_write(p->sub_socket, |
e8fa8f62 |
1270 | p->cfg.proxy_telnet_command + so, 2); |
0e8f4cda |
1271 | eo++; |
1272 | break; |
1273 | } |
1274 | } else { |
1275 | |
2d129d8e |
1276 | /* % escape. we recognize %%, %host, %port, %user, %pass. |
1277 | * anything else, we just send unescaped (including the %). |
1278 | */ |
0e8f4cda |
1279 | |
e8fa8f62 |
1280 | if (p->cfg.proxy_telnet_command[eo] == '%') { |
0e8f4cda |
1281 | sk_write(p->sub_socket, "%", 1); |
1282 | eo++; |
2d129d8e |
1283 | } |
e8fa8f62 |
1284 | else if (strnicmp(p->cfg.proxy_telnet_command + eo, |
0e8f4cda |
1285 | "host", 4) == 0) { |
b7a189f3 |
1286 | char dest[512]; |
1287 | sk_getaddr(p->remote_addr, dest, lenof(dest)); |
0e8f4cda |
1288 | sk_write(p->sub_socket, dest, strlen(dest)); |
1289 | eo += 4; |
2d129d8e |
1290 | } |
e8fa8f62 |
1291 | else if (strnicmp(p->cfg.proxy_telnet_command + eo, |
0e8f4cda |
1292 | "port", 4) == 0) { |
1293 | char port[8]; |
1294 | sprintf(port, "%i", p->remote_port); |
1295 | sk_write(p->sub_socket, port, strlen(port)); |
1296 | eo += 4; |
2d129d8e |
1297 | } |
e8fa8f62 |
1298 | else if (strnicmp(p->cfg.proxy_telnet_command + eo, |
2d129d8e |
1299 | "user", 4) == 0) { |
e8fa8f62 |
1300 | sk_write(p->sub_socket, p->cfg.proxy_username, |
1301 | strlen(p->cfg.proxy_username)); |
2d129d8e |
1302 | eo += 4; |
1303 | } |
e8fa8f62 |
1304 | else if (strnicmp(p->cfg.proxy_telnet_command + eo, |
2d129d8e |
1305 | "pass", 4) == 0) { |
e8fa8f62 |
1306 | sk_write(p->sub_socket, p->cfg.proxy_password, |
1307 | strlen(p->cfg.proxy_password)); |
2d129d8e |
1308 | eo += 4; |
1309 | } |
0e8f4cda |
1310 | else { |
1311 | /* we don't escape this, so send the % now, and |
1312 | * don't advance eo, so that we'll consider the |
1313 | * text immediately following the % as unescaped. |
1314 | */ |
1315 | sk_write(p->sub_socket, "%", 1); |
1316 | } |
1317 | } |
1318 | |
1319 | /* resume scanning for additional escapes after this one. */ |
1320 | so = eo; |
1321 | } |
1322 | |
1323 | /* if there is any unescaped text at the end of the line, send it */ |
1324 | if (eo != so) { |
e8fa8f62 |
1325 | sk_write(p->sub_socket, p->cfg.proxy_telnet_command + so, eo - so); |
0e8f4cda |
1326 | } |
1327 | |
1328 | p->state = 1; |
0e8f4cda |
1329 | return 0; |
1330 | } |
1331 | |
1332 | if (change == PROXY_CHANGE_CLOSING) { |
1333 | /* if our proxy negotiation process involves closing and opening |
1334 | * new sockets, then we would want to intercept this closing |
1335 | * callback when we were expecting it. if we aren't anticipating |
1336 | * a socket close, then some error must have occurred. we'll |
1337 | * just pass those errors up to the backend. |
1338 | */ |
1339 | return plug_closing(p->plug, p->closing_error_msg, |
1340 | p->closing_error_code, |
1341 | p->closing_calling_back); |
1342 | } |
1343 | |
1344 | if (change == PROXY_CHANGE_SENT) { |
1345 | /* some (or all) of what we wrote to the proxy was sent. |
1346 | * we don't do anything new, however, until we receive the |
1347 | * proxy's response. we might want to set a timer so we can |
1348 | * timeout the proxy negotiation after a while... |
1349 | */ |
1350 | return 0; |
1351 | } |
1352 | |
1353 | if (change == PROXY_CHANGE_ACCEPTING) { |
1354 | /* we should _never_ see this, as we are using our socket to |
1355 | * connect to a proxy, not accepting inbound connections. |
1356 | * what should we do? close the socket with an appropriate |
1357 | * error message? |
1358 | */ |
1359 | return plug_accepting(p->plug, p->accepting_sock); |
1360 | } |
1361 | |
1362 | if (change == PROXY_CHANGE_RECEIVE) { |
1363 | /* we have received data from the underlying socket, which |
1364 | * we'll need to parse, process, and respond to appropriately. |
1365 | */ |
1366 | |
1367 | /* we're done */ |
1368 | proxy_activate(p); |
1369 | /* proxy activate will have dealt with |
1370 | * whatever is left of the buffer */ |
1371 | return 1; |
1372 | } |
1373 | |
2192a8e4 |
1374 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
0e8f4cda |
1375 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
1376 | return 1; |
8eebd221 |
1377 | } |