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 || \ |
10068a0b |
19 | (cfg->proxy_dns == AUTO && \ |
20 | cfg->proxy_type != PROXY_SOCKS4 && \ |
21 | cfg->proxy_type != PROXY_SOCKS5)) |
b7a189f3 |
22 | |
8eebd221 |
23 | /* |
24 | * Call this when proxy negotiation is complete, so that this |
25 | * socket can begin working normally. |
26 | */ |
27 | void proxy_activate (Proxy_Socket p) |
28 | { |
29 | void *data; |
30 | int len; |
2d129d8e |
31 | long output_before, output_after; |
32 | |
8eebd221 |
33 | p->state = PROXY_STATE_ACTIVE; |
34 | |
2d129d8e |
35 | /* we want to ignore new receive events until we have sent |
36 | * all of our buffered receive data. |
37 | */ |
8eebd221 |
38 | sk_set_frozen(p->sub_socket, 1); |
39 | |
2d129d8e |
40 | /* how many bytes of output have we buffered? */ |
41 | output_before = bufchain_size(&p->pending_oob_output_data) + |
42 | bufchain_size(&p->pending_output_data); |
43 | /* and keep track of how many bytes do not get sent. */ |
44 | output_after = 0; |
45 | |
0e8f4cda |
46 | /* send buffered OOB writes */ |
8eebd221 |
47 | while (bufchain_size(&p->pending_oob_output_data) > 0) { |
48 | bufchain_prefix(&p->pending_oob_output_data, &data, &len); |
2d129d8e |
49 | output_after += sk_write_oob(p->sub_socket, data, len); |
8eebd221 |
50 | bufchain_consume(&p->pending_oob_output_data, len); |
51 | } |
8eebd221 |
52 | |
0e8f4cda |
53 | /* send buffered normal writes */ |
8eebd221 |
54 | while (bufchain_size(&p->pending_output_data) > 0) { |
55 | bufchain_prefix(&p->pending_output_data, &data, &len); |
2d129d8e |
56 | output_after += sk_write(p->sub_socket, data, len); |
8eebd221 |
57 | bufchain_consume(&p->pending_output_data, len); |
58 | } |
2d129d8e |
59 | |
60 | /* if we managed to send any data, let the higher levels know. */ |
61 | if (output_after < output_before) |
62 | plug_sent(p->plug, output_after); |
8eebd221 |
63 | |
0e8f4cda |
64 | /* if we were asked to flush the output during |
65 | * the proxy negotiation process, do so now. |
66 | */ |
8eebd221 |
67 | if (p->pending_flush) sk_flush(p->sub_socket); |
8eebd221 |
68 | |
2d129d8e |
69 | /* if the backend wanted the socket unfrozen, try to unfreeze. |
70 | * our set_frozen handler will flush buffered receive data before |
71 | * unfreezing the actual underlying socket. |
72 | */ |
73 | if (!p->freeze) |
74 | sk_set_frozen((Socket)p, 0); |
8eebd221 |
75 | } |
76 | |
77 | /* basic proxy socket functions */ |
78 | |
79 | static Plug sk_proxy_plug (Socket s, Plug p) |
80 | { |
81 | Proxy_Socket ps = (Proxy_Socket) s; |
82 | Plug ret = ps->plug; |
83 | if (p) |
84 | ps->plug = p; |
85 | return ret; |
86 | } |
87 | |
88 | static void sk_proxy_close (Socket s) |
89 | { |
90 | Proxy_Socket ps = (Proxy_Socket) s; |
91 | |
8eebd221 |
92 | sk_close(ps->sub_socket); |
93 | sfree(ps); |
94 | } |
95 | |
e0e7dff8 |
96 | static int sk_proxy_write (Socket s, const char *data, int len) |
8eebd221 |
97 | { |
98 | Proxy_Socket ps = (Proxy_Socket) s; |
99 | |
8eebd221 |
100 | if (ps->state != PROXY_STATE_ACTIVE) { |
101 | bufchain_add(&ps->pending_output_data, data, len); |
102 | return bufchain_size(&ps->pending_output_data); |
103 | } |
104 | return sk_write(ps->sub_socket, data, len); |
105 | } |
106 | |
e0e7dff8 |
107 | static int sk_proxy_write_oob (Socket s, const char *data, int len) |
8eebd221 |
108 | { |
109 | Proxy_Socket ps = (Proxy_Socket) s; |
110 | |
8eebd221 |
111 | if (ps->state != PROXY_STATE_ACTIVE) { |
112 | bufchain_clear(&ps->pending_output_data); |
113 | bufchain_clear(&ps->pending_oob_output_data); |
114 | bufchain_add(&ps->pending_oob_output_data, data, len); |
115 | return len; |
116 | } |
117 | return sk_write_oob(ps->sub_socket, data, len); |
118 | } |
119 | |
120 | static void sk_proxy_flush (Socket s) |
121 | { |
122 | Proxy_Socket ps = (Proxy_Socket) s; |
123 | |
8eebd221 |
124 | if (ps->state != PROXY_STATE_ACTIVE) { |
125 | ps->pending_flush = 1; |
126 | return; |
127 | } |
128 | sk_flush(ps->sub_socket); |
129 | } |
130 | |
131 | static void sk_proxy_set_private_ptr (Socket s, void *ptr) |
132 | { |
133 | Proxy_Socket ps = (Proxy_Socket) s; |
134 | sk_set_private_ptr(ps->sub_socket, ptr); |
135 | } |
136 | |
137 | static void * sk_proxy_get_private_ptr (Socket s) |
138 | { |
139 | Proxy_Socket ps = (Proxy_Socket) s; |
140 | return sk_get_private_ptr(ps->sub_socket); |
141 | } |
142 | |
143 | static void sk_proxy_set_frozen (Socket s, int is_frozen) |
144 | { |
145 | Proxy_Socket ps = (Proxy_Socket) s; |
146 | |
8eebd221 |
147 | if (ps->state != PROXY_STATE_ACTIVE) { |
148 | ps->freeze = is_frozen; |
149 | return; |
150 | } |
2d129d8e |
151 | |
152 | /* handle any remaining buffered recv data first */ |
153 | if (bufchain_size(&ps->pending_input_data) > 0) { |
154 | ps->freeze = is_frozen; |
155 | |
156 | /* loop while we still have buffered data, and while we are |
157 | * unfrozen. the plug_receive call in the loop could result |
158 | * in a call back into this function refreezing the socket, |
159 | * so we have to check each time. |
160 | */ |
161 | while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) { |
68a49acb |
162 | void *data; |
2d129d8e |
163 | int len; |
164 | bufchain_prefix(&ps->pending_input_data, &data, &len); |
165 | plug_receive(ps->plug, 0, data, len); |
166 | bufchain_consume(&ps->pending_input_data, len); |
167 | } |
168 | |
169 | /* if we're still frozen, we'll have to wait for another |
170 | * call from the backend to finish unbuffering the data. |
171 | */ |
172 | if (ps->freeze) return; |
173 | } |
174 | |
8eebd221 |
175 | sk_set_frozen(ps->sub_socket, is_frozen); |
176 | } |
177 | |
cbe2d68f |
178 | static const char * sk_proxy_socket_error (Socket s) |
8eebd221 |
179 | { |
180 | Proxy_Socket ps = (Proxy_Socket) s; |
181 | if (ps->error != NULL || ps->sub_socket == NULL) { |
182 | return ps->error; |
183 | } |
184 | return sk_socket_error(ps->sub_socket); |
185 | } |
186 | |
187 | /* basic proxy plug functions */ |
188 | |
cbe2d68f |
189 | static int plug_proxy_closing (Plug p, const char *error_msg, |
8eebd221 |
190 | int error_code, int calling_back) |
191 | { |
192 | Proxy_Plug pp = (Proxy_Plug) p; |
193 | Proxy_Socket ps = pp->proxy_socket; |
194 | |
8eebd221 |
195 | if (ps->state != PROXY_STATE_ACTIVE) { |
196 | ps->closing_error_msg = error_msg; |
197 | ps->closing_error_code = error_code; |
198 | ps->closing_calling_back = calling_back; |
199 | return ps->negotiate(ps, PROXY_CHANGE_CLOSING); |
200 | } |
201 | return plug_closing(ps->plug, error_msg, |
202 | error_code, calling_back); |
203 | } |
204 | |
205 | static int plug_proxy_receive (Plug p, int urgent, char *data, int len) |
206 | { |
207 | Proxy_Plug pp = (Proxy_Plug) p; |
208 | Proxy_Socket ps = pp->proxy_socket; |
209 | |
8eebd221 |
210 | if (ps->state != PROXY_STATE_ACTIVE) { |
211 | /* we will lose the urgentness of this data, but since most, |
212 | * if not all, of this data will be consumed by the negotiation |
213 | * process, hopefully it won't affect the protocol above us |
214 | */ |
215 | bufchain_add(&ps->pending_input_data, data, len); |
216 | ps->receive_urgent = urgent; |
217 | ps->receive_data = data; |
218 | ps->receive_len = len; |
219 | return ps->negotiate(ps, PROXY_CHANGE_RECEIVE); |
220 | } |
221 | return plug_receive(ps->plug, urgent, data, len); |
222 | } |
223 | |
224 | static void plug_proxy_sent (Plug p, int bufsize) |
225 | { |
226 | Proxy_Plug pp = (Proxy_Plug) p; |
227 | Proxy_Socket ps = pp->proxy_socket; |
228 | |
8eebd221 |
229 | if (ps->state != PROXY_STATE_ACTIVE) { |
230 | ps->sent_bufsize = bufsize; |
231 | ps->negotiate(ps, PROXY_CHANGE_SENT); |
232 | return; |
233 | } |
234 | plug_sent(ps->plug, bufsize); |
235 | } |
236 | |
f7f9fb5c |
237 | static int plug_proxy_accepting (Plug p, OSSocket sock) |
8eebd221 |
238 | { |
239 | Proxy_Plug pp = (Proxy_Plug) p; |
240 | Proxy_Socket ps = pp->proxy_socket; |
241 | |
8eebd221 |
242 | if (ps->state != PROXY_STATE_ACTIVE) { |
243 | ps->accepting_sock = sock; |
244 | return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING); |
245 | } |
246 | return plug_accepting(ps->plug, sock); |
247 | } |
248 | |
b7a189f3 |
249 | /* |
250 | * This function can accept a NULL pointer as `addr', in which case |
251 | * it will only check the host name. |
252 | */ |
e8fa8f62 |
253 | static int proxy_for_destination (SockAddr addr, char *hostname, int port, |
254 | const Config *cfg) |
8eebd221 |
255 | { |
256 | int s = 0, e = 0; |
257 | char hostip[64]; |
258 | int hostip_len, hostname_len; |
e8fa8f62 |
259 | const char *exclude_list; |
8eebd221 |
260 | |
b804e1e5 |
261 | /* |
262 | * Check the host name and IP against the hard-coded |
263 | * representations of `localhost'. |
264 | */ |
e8fa8f62 |
265 | if (!cfg->even_proxy_localhost && |
b7a189f3 |
266 | (sk_hostname_is_local(hostname) || |
267 | (addr && sk_address_is_local(addr)))) |
b804e1e5 |
268 | return 0; /* do not proxy */ |
269 | |
8eebd221 |
270 | /* we want a string representation of the IP address for comparisons */ |
b7a189f3 |
271 | if (addr) { |
272 | sk_getaddr(addr, hostip, 64); |
273 | hostip_len = strlen(hostip); |
7ffdbc1a |
274 | } else |
275 | hostip_len = 0; /* placate gcc; shouldn't be required */ |
8eebd221 |
276 | |
8eebd221 |
277 | hostname_len = strlen(hostname); |
278 | |
e8fa8f62 |
279 | exclude_list = cfg->proxy_exclude_list; |
8eebd221 |
280 | |
281 | /* now parse the exclude list, and see if either our IP |
282 | * or hostname matches anything in it. |
283 | */ |
284 | |
285 | while (exclude_list[s]) { |
286 | while (exclude_list[s] && |
e93ed432 |
287 | (isspace((unsigned char)exclude_list[s]) || |
8eebd221 |
288 | exclude_list[s] == ',')) s++; |
289 | |
290 | if (!exclude_list[s]) break; |
291 | |
292 | e = s; |
293 | |
294 | while (exclude_list[e] && |
e93ed432 |
295 | (isalnum((unsigned char)exclude_list[e]) || |
8eebd221 |
296 | exclude_list[e] == '-' || |
297 | exclude_list[e] == '.' || |
298 | exclude_list[e] == '*')) e++; |
299 | |
300 | if (exclude_list[s] == '*') { |
301 | /* wildcard at beginning of entry */ |
302 | |
b7a189f3 |
303 | if ((addr && strnicmp(hostip + hostip_len - (e - s - 1), |
304 | exclude_list + s + 1, e - s - 1) == 0) || |
8eebd221 |
305 | strnicmp(hostname + hostname_len - (e - s - 1), |
306 | exclude_list + s + 1, e - s - 1) == 0) |
307 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
308 | |
309 | } else if (exclude_list[e-1] == '*') { |
310 | /* wildcard at end of entry */ |
311 | |
b7a189f3 |
312 | if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) || |
8eebd221 |
313 | strnicmp(hostname, exclude_list + s, e - s - 1) == 0) |
314 | return 0; /* IP/hostname range excluded. do not use proxy. */ |
315 | |
316 | } else { |
317 | /* no wildcard at either end, so let's try an absolute |
318 | * match (ie. a specific IP) |
319 | */ |
320 | |
b7a189f3 |
321 | if (addr && stricmp(hostip, exclude_list + s) == 0) |
8eebd221 |
322 | return 0; /* IP/hostname excluded. do not use proxy. */ |
323 | if (stricmp(hostname, exclude_list + s) == 0) |
324 | return 0; /* IP/hostname excluded. do not use proxy. */ |
325 | } |
326 | |
327 | s = e; |
1b08e5d7 |
328 | |
329 | /* Make sure we really have reached the next comma or end-of-string */ |
330 | while (exclude_list[s] && |
e93ed432 |
331 | !isspace((unsigned char)exclude_list[s]) && |
1b08e5d7 |
332 | exclude_list[s] != ',') s++; |
8eebd221 |
333 | } |
334 | |
335 | /* no matches in the exclude list, so use the proxy */ |
336 | return 1; |
337 | } |
338 | |
e8fa8f62 |
339 | SockAddr name_lookup(char *host, int port, char **canonicalname, |
340 | const Config *cfg) |
b7a189f3 |
341 | { |
e8fa8f62 |
342 | if (cfg->proxy_type != PROXY_NONE && |
343 | do_proxy_dns(cfg) && |
344 | proxy_for_destination(NULL, host, port, cfg)) { |
b7a189f3 |
345 | *canonicalname = dupstr(host); |
346 | return sk_nonamelookup(host); |
347 | } |
348 | |
349 | return sk_namelookup(host, canonicalname); |
350 | } |
351 | |
0f0a2507 |
352 | Socket platform_new_connection(SockAddr addr, char *hostname, |
353 | int port, int privport, |
354 | int oobinline, int nodelay, Plug plug, |
355 | const Config *cfg); |
356 | |
8eebd221 |
357 | Socket new_connection(SockAddr addr, char *hostname, |
358 | int port, int privport, |
e8fa8f62 |
359 | int oobinline, int nodelay, Plug plug, |
360 | const Config *cfg) |
8eebd221 |
361 | { |
7b6c9b99 |
362 | static const struct socket_function_table socket_fn_table = { |
8eebd221 |
363 | sk_proxy_plug, |
364 | sk_proxy_close, |
365 | sk_proxy_write, |
366 | sk_proxy_write_oob, |
367 | sk_proxy_flush, |
368 | sk_proxy_set_private_ptr, |
369 | sk_proxy_get_private_ptr, |
370 | sk_proxy_set_frozen, |
371 | sk_proxy_socket_error |
372 | }; |
373 | |
7b6c9b99 |
374 | static const struct plug_function_table plug_fn_table = { |
8eebd221 |
375 | plug_proxy_closing, |
376 | plug_proxy_receive, |
377 | plug_proxy_sent, |
378 | plug_proxy_accepting |
379 | }; |
380 | |
e8fa8f62 |
381 | if (cfg->proxy_type != PROXY_NONE && |
382 | proxy_for_destination(addr, hostname, port, cfg)) |
8eebd221 |
383 | { |
384 | Proxy_Socket ret; |
385 | Proxy_Plug pplug; |
386 | SockAddr proxy_addr; |
cbe2d68f |
387 | char *proxy_canonical_name; |
0f0a2507 |
388 | Socket sret; |
389 | |
390 | if ( (sret = platform_new_connection(addr, hostname, port, privport, |
391 | oobinline, nodelay, plug, cfg)) ) |
392 | return sret; |
8eebd221 |
393 | |
3d88e64d |
394 | ret = snew(struct Socket_proxy_tag); |
8eebd221 |
395 | ret->fn = &socket_fn_table; |
e8fa8f62 |
396 | ret->cfg = *cfg; /* STRUCTURE COPY */ |
8eebd221 |
397 | ret->plug = plug; |
398 | ret->remote_addr = addr; |
399 | ret->remote_port = port; |
400 | |
65c78e88 |
401 | ret->error = NULL; |
402 | ret->pending_flush = 0; |
403 | ret->freeze = 0; |
404 | |
8eebd221 |
405 | bufchain_init(&ret->pending_input_data); |
406 | bufchain_init(&ret->pending_output_data); |
407 | bufchain_init(&ret->pending_oob_output_data); |
408 | |
8eebd221 |
409 | ret->sub_socket = NULL; |
410 | ret->state = PROXY_STATE_NEW; |
2d129d8e |
411 | ret->negotiate = NULL; |
412 | |
e8fa8f62 |
413 | if (cfg->proxy_type == PROXY_HTTP) { |
8eebd221 |
414 | ret->negotiate = proxy_http_negotiate; |
10068a0b |
415 | } else if (cfg->proxy_type == PROXY_SOCKS4) { |
416 | ret->negotiate = proxy_socks4_negotiate; |
417 | } else if (cfg->proxy_type == PROXY_SOCKS5) { |
418 | ret->negotiate = proxy_socks5_negotiate; |
e8fa8f62 |
419 | } else if (cfg->proxy_type == PROXY_TELNET) { |
8eebd221 |
420 | ret->negotiate = proxy_telnet_negotiate; |
421 | } else { |
7983f47e |
422 | ret->error = "Proxy error: Unknown proxy method"; |
8eebd221 |
423 | return (Socket) ret; |
424 | } |
425 | |
426 | /* create the proxy plug to map calls from the actual |
427 | * socket into our proxy socket layer */ |
3d88e64d |
428 | pplug = snew(struct Plug_proxy_tag); |
8eebd221 |
429 | pplug->fn = &plug_fn_table; |
430 | pplug->proxy_socket = ret; |
431 | |
432 | /* look-up proxy */ |
e8fa8f62 |
433 | proxy_addr = sk_namelookup(cfg->proxy_host, |
8eebd221 |
434 | &proxy_canonical_name); |
cbe2d68f |
435 | if (sk_addr_error(proxy_addr) != NULL) { |
42389a9e |
436 | ret->error = "Proxy error: Unable to resolve proxy host name"; |
437 | return (Socket)ret; |
438 | } |
8eebd221 |
439 | sfree(proxy_canonical_name); |
440 | |
441 | /* create the actual socket we will be using, |
442 | * connected to our proxy server and port. |
443 | */ |
e8fa8f62 |
444 | ret->sub_socket = sk_new(proxy_addr, cfg->proxy_port, |
8eebd221 |
445 | privport, oobinline, |
446 | nodelay, (Plug) pplug); |
447 | if (sk_socket_error(ret->sub_socket) != NULL) |
448 | return (Socket) ret; |
449 | |
450 | sk_addr_free(proxy_addr); |
451 | |
452 | /* start the proxy negotiation process... */ |
453 | sk_set_frozen(ret->sub_socket, 0); |
454 | ret->negotiate(ret, PROXY_CHANGE_NEW); |
455 | |
456 | return (Socket) ret; |
457 | } |
458 | |
459 | /* no proxy, so just return the direct socket */ |
460 | return sk_new(addr, port, privport, oobinline, nodelay, plug); |
461 | } |
462 | |
e8fa8f62 |
463 | Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only, |
464 | const Config *cfg) |
8eebd221 |
465 | { |
466 | /* TODO: SOCKS (and potentially others) support inbound |
467 | * TODO: connections via the proxy. support them. |
468 | */ |
469 | |
6ee9b735 |
470 | return sk_newlistener(srcaddr, port, plug, local_host_only); |
8eebd221 |
471 | } |
472 | |
473 | /* ---------------------------------------------------------------------- |
474 | * HTTP CONNECT proxy type. |
475 | */ |
476 | |
477 | static int get_line_end (char * data, int len) |
478 | { |
479 | int off = 0; |
480 | |
481 | while (off < len) |
482 | { |
483 | if (data[off] == '\n') { |
484 | /* we have a newline */ |
485 | off++; |
486 | |
487 | /* is that the only thing on this line? */ |
488 | if (off <= 2) return off; |
489 | |
490 | /* if not, then there is the possibility that this header |
491 | * continues onto the next line, if it starts with a space |
492 | * or a tab. |
493 | */ |
494 | |
495 | if (off + 1 < len && |
496 | data[off+1] != ' ' && |
497 | data[off+1] != '\t') return off; |
498 | |
499 | /* the line does continue, so we have to keep going |
500 | * until we see an the header's "real" end of line. |
501 | */ |
502 | off++; |
503 | } |
504 | |
505 | off++; |
506 | } |
507 | |
508 | return -1; |
509 | } |
510 | |
511 | int proxy_http_negotiate (Proxy_Socket p, int change) |
512 | { |
513 | if (p->state == PROXY_STATE_NEW) { |
514 | /* we are just beginning the proxy negotiate process, |
515 | * so we'll send off the initial bits of the request. |
516 | * for this proxy method, it's just a simple HTTP |
517 | * request |
518 | */ |
b7a189f3 |
519 | char *buf, dest[512]; |
8eebd221 |
520 | |
b7a189f3 |
521 | sk_getaddr(p->remote_addr, dest, lenof(dest)); |
8eebd221 |
522 | |
57356d63 |
523 | buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n", |
524 | dest, p->remote_port, dest, p->remote_port); |
8eebd221 |
525 | sk_write(p->sub_socket, buf, strlen(buf)); |
57356d63 |
526 | sfree(buf); |
8eebd221 |
527 | |
e8fa8f62 |
528 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
529 | char buf[sizeof(p->cfg.proxy_username)+sizeof(p->cfg.proxy_password)]; |
1549e076 |
530 | char buf2[sizeof(buf)*4/3 + 100]; |
531 | int i, j, len; |
e8fa8f62 |
532 | sprintf(buf, "%s:%s", p->cfg.proxy_username, p->cfg.proxy_password); |
1549e076 |
533 | len = strlen(buf); |
6c434e1f |
534 | sprintf(buf2, "Proxy-Authorization: Basic "); |
1549e076 |
535 | for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4) |
616a115c |
536 | base64_encode_atom((unsigned char *)(buf+i), |
537 | (len-i > 3 ? 3 : len-i), buf2+j); |
1549e076 |
538 | strcpy(buf2+j, "\r\n"); |
539 | sk_write(p->sub_socket, buf2, strlen(buf2)); |
540 | } |
541 | |
9ddf18a4 |
542 | sk_write(p->sub_socket, "\r\n", 2); |
1549e076 |
543 | |
8eebd221 |
544 | p->state = 1; |
8eebd221 |
545 | return 0; |
546 | } |
547 | |
548 | if (change == PROXY_CHANGE_CLOSING) { |
549 | /* if our proxy negotiation process involves closing and opening |
550 | * new sockets, then we would want to intercept this closing |
551 | * callback when we were expecting it. if we aren't anticipating |
552 | * a socket close, then some error must have occurred. we'll |
553 | * just pass those errors up to the backend. |
554 | */ |
555 | return plug_closing(p->plug, p->closing_error_msg, |
556 | p->closing_error_code, |
557 | p->closing_calling_back); |
558 | } |
559 | |
560 | if (change == PROXY_CHANGE_SENT) { |
561 | /* some (or all) of what we wrote to the proxy was sent. |
562 | * we don't do anything new, however, until we receive the |
563 | * proxy's response. we might want to set a timer so we can |
564 | * timeout the proxy negotiation after a while... |
565 | */ |
566 | return 0; |
567 | } |
568 | |
569 | if (change == PROXY_CHANGE_ACCEPTING) { |
570 | /* we should _never_ see this, as we are using our socket to |
571 | * connect to a proxy, not accepting inbound connections. |
572 | * what should we do? close the socket with an appropriate |
573 | * error message? |
574 | */ |
575 | return plug_accepting(p->plug, p->accepting_sock); |
576 | } |
577 | |
578 | if (change == PROXY_CHANGE_RECEIVE) { |
579 | /* we have received data from the underlying socket, which |
580 | * we'll need to parse, process, and respond to appropriately. |
581 | */ |
582 | |
7983f47e |
583 | char *data, *datap; |
8eebd221 |
584 | int len; |
585 | int eol; |
586 | |
587 | if (p->state == 1) { |
588 | |
589 | int min_ver, maj_ver, status; |
590 | |
591 | /* get the status line */ |
7983f47e |
592 | len = bufchain_size(&p->pending_input_data); |
593 | assert(len > 0); /* or we wouldn't be here */ |
3d88e64d |
594 | data = snewn(len, char); |
7983f47e |
595 | bufchain_fetch(&p->pending_input_data, data, len); |
596 | |
8eebd221 |
597 | eol = get_line_end(data, len); |
7983f47e |
598 | if (eol < 0) { |
599 | sfree(data); |
600 | return 1; |
601 | } |
8eebd221 |
602 | |
7983f47e |
603 | status = -1; |
604 | /* We can't rely on whether the %n incremented the sscanf return */ |
605 | if (sscanf((char *)data, "HTTP/%i.%i %n", |
606 | &maj_ver, &min_ver, &status) < 2 || status == -1) { |
607 | plug_closing(p->plug, "Proxy error: HTTP response was absent", |
608 | PROXY_ERROR_GENERAL, 0); |
609 | sfree(data); |
610 | return 1; |
611 | } |
8eebd221 |
612 | |
613 | /* remove the status line from the input buffer. */ |
614 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
615 | if (data[status] != '2') { |
8eebd221 |
616 | /* error */ |
57356d63 |
617 | char *buf; |
7983f47e |
618 | data[eol] = '\0'; |
619 | while (eol > status && |
620 | (data[eol-1] == '\r' || data[eol-1] == '\n')) |
621 | data[--eol] = '\0'; |
57356d63 |
622 | buf = dupprintf("Proxy error: %s", data+status); |
7983f47e |
623 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
57356d63 |
624 | sfree(buf); |
7983f47e |
625 | sfree(data); |
8eebd221 |
626 | return 1; |
627 | } |
628 | |
7983f47e |
629 | sfree(data); |
630 | |
8eebd221 |
631 | p->state = 2; |
632 | } |
633 | |
634 | if (p->state == 2) { |
635 | |
636 | /* get headers. we're done when we get a |
637 | * header of length 2, (ie. just "\r\n") |
638 | */ |
639 | |
7983f47e |
640 | len = bufchain_size(&p->pending_input_data); |
641 | assert(len > 0); /* or we wouldn't be here */ |
3d88e64d |
642 | data = snewn(len, char); |
7983f47e |
643 | datap = data; |
644 | bufchain_fetch(&p->pending_input_data, data, len); |
645 | |
646 | eol = get_line_end(datap, len); |
647 | if (eol < 0) { |
648 | sfree(data); |
649 | return 1; |
650 | } |
8eebd221 |
651 | while (eol > 2) |
652 | { |
8eebd221 |
653 | bufchain_consume(&p->pending_input_data, eol); |
7983f47e |
654 | datap += eol; |
9ddf18a4 |
655 | len -= eol; |
7983f47e |
656 | eol = get_line_end(datap, len); |
8eebd221 |
657 | } |
658 | |
659 | if (eol == 2) { |
660 | /* we're done */ |
661 | bufchain_consume(&p->pending_input_data, 2); |
662 | proxy_activate(p); |
663 | /* proxy activate will have dealt with |
664 | * whatever is left of the buffer */ |
7983f47e |
665 | sfree(data); |
8eebd221 |
666 | return 1; |
667 | } |
668 | |
7983f47e |
669 | sfree(data); |
8eebd221 |
670 | return 1; |
671 | } |
672 | } |
673 | |
7983f47e |
674 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
8eebd221 |
675 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
676 | return 1; |
8eebd221 |
677 | } |
678 | |
679 | /* ---------------------------------------------------------------------- |
6971bbe7 |
680 | * SOCKS proxy type. |
8eebd221 |
681 | */ |
682 | |
6971bbe7 |
683 | /* SOCKS version 4 */ |
684 | int proxy_socks4_negotiate (Proxy_Socket p, int change) |
8eebd221 |
685 | { |
6971bbe7 |
686 | if (p->state == PROXY_CHANGE_NEW) { |
687 | |
688 | /* request format: |
689 | * version number (1 byte) = 4 |
690 | * command code (1 byte) |
691 | * 1 = CONNECT |
692 | * 2 = BIND |
693 | * dest. port (2 bytes) [network order] |
694 | * dest. address (4 bytes) |
695 | * user ID (variable length, null terminated string) |
696 | */ |
697 | |
b7a189f3 |
698 | int length, type, namelen; |
699 | char *command, addr[4], hostname[512]; |
6971bbe7 |
700 | |
b7a189f3 |
701 | type = sk_addrtype(p->remote_addr); |
702 | if (type == ADDRTYPE_IPV6) { |
7983f47e |
703 | plug_closing(p->plug, "Proxy error: SOCKS version 4 does" |
704 | " not support IPv6", PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
705 | return 1; |
b7a189f3 |
706 | } else if (type == ADDRTYPE_IPV4) { |
707 | namelen = 0; |
708 | sk_addrcopy(p->remote_addr, addr); |
709 | } else { /* type == ADDRTYPE_NAME */ |
5e391f65 |
710 | assert(type == ADDRTYPE_NAME); |
b7a189f3 |
711 | sk_getaddr(p->remote_addr, hostname, lenof(hostname)); |
712 | namelen = strlen(hostname) + 1; /* include the NUL */ |
713 | addr[0] = addr[1] = addr[2] = 0; |
714 | addr[3] = 1; |
6971bbe7 |
715 | } |
716 | |
e8fa8f62 |
717 | length = strlen(p->cfg.proxy_username) + namelen + 9; |
3d88e64d |
718 | command = snewn(length, char); |
e8fa8f62 |
719 | strcpy(command + 8, p->cfg.proxy_username); |
6971bbe7 |
720 | |
721 | command[0] = 4; /* version 4 */ |
722 | command[1] = 1; /* CONNECT command */ |
723 | |
724 | /* port */ |
725 | command[2] = (char) (p->remote_port >> 8) & 0xff; |
726 | command[3] = (char) p->remote_port & 0xff; |
727 | |
728 | /* address */ |
b7a189f3 |
729 | memcpy(command + 4, addr, 4); |
730 | |
731 | /* hostname */ |
e8fa8f62 |
732 | memcpy(command + 8 + strlen(p->cfg.proxy_username) + 1, |
b7a189f3 |
733 | hostname, namelen); |
6971bbe7 |
734 | |
735 | sk_write(p->sub_socket, command, length); |
de9aaffb |
736 | sfree(command); |
6971bbe7 |
737 | |
738 | p->state = 1; |
739 | return 0; |
740 | } |
741 | |
742 | if (change == PROXY_CHANGE_CLOSING) { |
743 | /* if our proxy negotiation process involves closing and opening |
744 | * new sockets, then we would want to intercept this closing |
745 | * callback when we were expecting it. if we aren't anticipating |
746 | * a socket close, then some error must have occurred. we'll |
747 | * just pass those errors up to the backend. |
748 | */ |
749 | return plug_closing(p->plug, p->closing_error_msg, |
750 | p->closing_error_code, |
751 | p->closing_calling_back); |
752 | } |
753 | |
754 | if (change == PROXY_CHANGE_SENT) { |
755 | /* some (or all) of what we wrote to the proxy was sent. |
756 | * we don't do anything new, however, until we receive the |
757 | * proxy's response. we might want to set a timer so we can |
758 | * timeout the proxy negotiation after a while... |
759 | */ |
760 | return 0; |
761 | } |
762 | |
763 | if (change == PROXY_CHANGE_ACCEPTING) { |
764 | /* we should _never_ see this, as we are using our socket to |
765 | * connect to a proxy, not accepting inbound connections. |
766 | * what should we do? close the socket with an appropriate |
767 | * error message? |
768 | */ |
769 | return plug_accepting(p->plug, p->accepting_sock); |
770 | } |
771 | |
772 | if (change == PROXY_CHANGE_RECEIVE) { |
773 | /* we have received data from the underlying socket, which |
774 | * we'll need to parse, process, and respond to appropriately. |
775 | */ |
776 | |
777 | if (p->state == 1) { |
778 | /* response format: |
779 | * version number (1 byte) = 4 |
780 | * reply code (1 byte) |
781 | * 90 = request granted |
782 | * 91 = request rejected or failed |
783 | * 92 = request rejected due to lack of IDENTD on client |
784 | * 93 = request rejected due to difference in user ID |
785 | * (what we sent vs. what IDENTD said) |
786 | * dest. port (2 bytes) |
787 | * dest. address (4 bytes) |
788 | */ |
789 | |
7983f47e |
790 | char data[8]; |
6971bbe7 |
791 | |
7983f47e |
792 | if (bufchain_size(&p->pending_input_data) < 8) |
793 | return 1; /* not got anything yet */ |
794 | |
6971bbe7 |
795 | /* get the response */ |
7983f47e |
796 | bufchain_fetch(&p->pending_input_data, data, 8); |
6971bbe7 |
797 | |
798 | if (data[0] != 0) { |
7983f47e |
799 | plug_closing(p->plug, "Proxy error: SOCKS proxy responded with " |
6971bbe7 |
800 | "unexpected reply code version", |
801 | PROXY_ERROR_GENERAL, 0); |
802 | return 1; |
803 | } |
804 | |
805 | if (data[1] != 90) { |
806 | |
807 | switch (data[1]) { |
808 | case 92: |
7983f47e |
809 | plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client", |
6971bbe7 |
810 | PROXY_ERROR_GENERAL, 0); |
811 | break; |
812 | case 93: |
7983f47e |
813 | plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree", |
6971bbe7 |
814 | PROXY_ERROR_GENERAL, 0); |
815 | break; |
816 | case 91: |
817 | default: |
7983f47e |
818 | plug_closing(p->plug, "Proxy error: Error while communicating with proxy", |
6971bbe7 |
819 | PROXY_ERROR_GENERAL, 0); |
820 | break; |
821 | } |
822 | |
823 | return 1; |
824 | } |
7983f47e |
825 | bufchain_consume(&p->pending_input_data, 8); |
6971bbe7 |
826 | |
827 | /* we're done */ |
828 | proxy_activate(p); |
829 | /* proxy activate will have dealt with |
830 | * whatever is left of the buffer */ |
831 | return 1; |
832 | } |
833 | } |
834 | |
7983f47e |
835 | plug_closing(p->plug, "Proxy error: unexpected proxy error", |
6971bbe7 |
836 | PROXY_ERROR_UNEXPECTED, 0); |
837 | return 1; |
838 | } |
839 | |
840 | /* SOCKS version 5 */ |
841 | int proxy_socks5_negotiate (Proxy_Socket p, int change) |
842 | { |
843 | if (p->state == PROXY_CHANGE_NEW) { |
844 | |
845 | /* initial command: |
846 | * version number (1 byte) = 5 |
847 | * number of available authentication methods (1 byte) |
848 | * available authentication methods (1 byte * previous value) |
849 | * authentication methods: |
850 | * 0x00 = no authentication |
851 | * 0x01 = GSSAPI |
852 | * 0x02 = username/password |
853 | * 0x03 = CHAP |
854 | */ |
855 | |
aab91a3e |
856 | char command[4]; |
857 | int len; |
6971bbe7 |
858 | |
859 | command[0] = 5; /* version 5 */ |
e8fa8f62 |
860 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
aab91a3e |
861 | command[1] = 2; /* two methods supported: */ |
862 | command[2] = 0x00; /* no authentication */ |
863 | command[3] = 0x02; /* username/password */ |
864 | len = 4; |
865 | } else { |
866 | command[1] = 1; /* one methods supported: */ |
867 | command[2] = 0x00; /* no authentication */ |
868 | len = 3; |
869 | } |
6971bbe7 |
870 | |
aab91a3e |
871 | sk_write(p->sub_socket, command, len); |
6971bbe7 |
872 | |
873 | p->state = 1; |
874 | return 0; |
875 | } |
876 | |
877 | if (change == PROXY_CHANGE_CLOSING) { |
878 | /* if our proxy negotiation process involves closing and opening |
879 | * new sockets, then we would want to intercept this closing |
880 | * callback when we were expecting it. if we aren't anticipating |
881 | * a socket close, then some error must have occurred. we'll |
882 | * just pass those errors up to the backend. |
883 | */ |
884 | return plug_closing(p->plug, p->closing_error_msg, |
885 | p->closing_error_code, |
886 | p->closing_calling_back); |
887 | } |
888 | |
889 | if (change == PROXY_CHANGE_SENT) { |
890 | /* some (or all) of what we wrote to the proxy was sent. |
891 | * we don't do anything new, however, until we receive the |
892 | * proxy's response. we might want to set a timer so we can |
893 | * timeout the proxy negotiation after a while... |
894 | */ |
895 | return 0; |
896 | } |
897 | |
898 | if (change == PROXY_CHANGE_ACCEPTING) { |
899 | /* we should _never_ see this, as we are using our socket to |
900 | * connect to a proxy, not accepting inbound connections. |
901 | * what should we do? close the socket with an appropriate |
902 | * error message? |
903 | */ |
904 | return plug_accepting(p->plug, p->accepting_sock); |
905 | } |
906 | |
907 | if (change == PROXY_CHANGE_RECEIVE) { |
908 | /* we have received data from the underlying socket, which |
909 | * we'll need to parse, process, and respond to appropriately. |
910 | */ |
911 | |
6971bbe7 |
912 | if (p->state == 1) { |
913 | |
914 | /* initial response: |
915 | * version number (1 byte) = 5 |
916 | * authentication method (1 byte) |
917 | * authentication methods: |
918 | * 0x00 = no authentication |
919 | * 0x01 = GSSAPI |
920 | * 0x02 = username/password |
921 | * 0x03 = CHAP |
922 | * 0xff = no acceptable methods |
923 | */ |
7983f47e |
924 | char data[2]; |
925 | |
926 | if (bufchain_size(&p->pending_input_data) < 2) |
927 | return 1; /* not got anything yet */ |
6971bbe7 |
928 | |
929 | /* get the response */ |
7983f47e |
930 | bufchain_fetch(&p->pending_input_data, data, 2); |
6971bbe7 |
931 | |
932 | if (data[0] != 5) { |
7983f47e |
933 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version", |
6971bbe7 |
934 | PROXY_ERROR_GENERAL, 0); |
935 | return 1; |
936 | } |
937 | |
938 | if (data[1] == 0x00) p->state = 2; /* no authentication needed */ |
939 | else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */ |
940 | else if (data[1] == 0x02) p->state = 5; /* username/password authentication */ |
941 | else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */ |
942 | else { |
7983f47e |
943 | plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication", |
6971bbe7 |
944 | PROXY_ERROR_GENERAL, 0); |
945 | return 1; |
946 | } |
aab91a3e |
947 | bufchain_consume(&p->pending_input_data, 2); |
948 | } |
949 | |
950 | if (p->state == 7) { |
951 | |
952 | /* password authentication reply format: |
953 | * version number (1 bytes) = 1 |
954 | * reply code (1 byte) |
955 | * 0 = succeeded |
956 | * >0 = failed |
957 | */ |
7983f47e |
958 | char data[2]; |
959 | |
960 | if (bufchain_size(&p->pending_input_data) < 2) |
961 | return 1; /* not got anything yet */ |
aab91a3e |
962 | |
963 | /* get the response */ |
7983f47e |
964 | bufchain_fetch(&p->pending_input_data, data, 2); |
aab91a3e |
965 | |
966 | if (data[0] != 1) { |
7983f47e |
967 | plug_closing(p->plug, "Proxy error: SOCKS password " |
968 | "subnegotiation contained wrong version number", |
aab91a3e |
969 | PROXY_ERROR_GENERAL, 0); |
970 | return 1; |
971 | } |
972 | |
973 | if (data[1] != 0) { |
974 | |
7983f47e |
975 | plug_closing(p->plug, "Proxy error: SOCKS proxy refused" |
976 | " password authentication", |
aab91a3e |
977 | PROXY_ERROR_GENERAL, 0); |
978 | return 1; |
979 | } |
980 | |
981 | bufchain_consume(&p->pending_input_data, 2); |
982 | p->state = 2; /* now proceed as authenticated */ |
6971bbe7 |
983 | } |
984 | |
985 | if (p->state == 2) { |
986 | |
987 | /* request format: |
988 | * version number (1 byte) = 5 |
989 | * command code (1 byte) |
990 | * 1 = CONNECT |
991 | * 2 = BIND |
992 | * 3 = UDP ASSOCIATE |
993 | * reserved (1 byte) = 0x00 |
994 | * address type (1 byte) |
995 | * 1 = IPv4 |
996 | * 3 = domainname (first byte has length, no terminating null) |
997 | * 4 = IPv6 |
998 | * dest. address (variable) |
999 | * dest. port (2 bytes) [network order] |
1000 | */ |
1001 | |
b7a189f3 |
1002 | char command[512]; |
6971bbe7 |
1003 | int len; |
b7a189f3 |
1004 | int type; |
6971bbe7 |
1005 | |
b7a189f3 |
1006 | type = sk_addrtype(p->remote_addr); |
1007 | if (type == ADDRTYPE_IPV4) { |
1008 | len = 10; /* 4 hdr + 4 addr + 2 trailer */ |
6971bbe7 |
1009 | command[3] = 1; /* IPv4 */ |
b7a189f3 |
1010 | sk_addrcopy(p->remote_addr, command+4); |
1011 | } else if (type == ADDRTYPE_IPV6) { |
1012 | len = 22; /* 4 hdr + 16 addr + 2 trailer */ |
6971bbe7 |
1013 | command[3] = 4; /* IPv6 */ |
b7a189f3 |
1014 | sk_addrcopy(p->remote_addr, command+4); |
5e391f65 |
1015 | } else { |
1016 | assert(type == ADDRTYPE_NAME); |
b7a189f3 |
1017 | command[3] = 3; |
1018 | sk_getaddr(p->remote_addr, command+5, 256); |
1019 | command[4] = strlen(command+5); |
1020 | len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */ |
6971bbe7 |
1021 | } |
1022 | |
1023 | command[0] = 5; /* version 5 */ |
1024 | command[1] = 1; /* CONNECT command */ |
1025 | command[2] = 0x00; |
1026 | |
6971bbe7 |
1027 | /* port */ |
1028 | command[len-2] = (char) (p->remote_port >> 8) & 0xff; |
1029 | command[len-1] = (char) p->remote_port & 0xff; |
1030 | |
1031 | sk_write(p->sub_socket, command, len); |
1032 | |
1033 | p->state = 3; |
1034 | return 1; |
1035 | } |
1036 | |
1037 | if (p->state == 3) { |
1038 | |
1039 | /* reply format: |
1040 | * version number (1 bytes) = 5 |
1041 | * reply code (1 byte) |
1042 | * 0 = succeeded |
1043 | * 1 = general SOCKS server failure |
1044 | * 2 = connection not allowed by ruleset |
1045 | * 3 = network unreachable |
1046 | * 4 = host unreachable |
1047 | * 5 = connection refused |
1048 | * 6 = TTL expired |
1049 | * 7 = command not supported |
1050 | * 8 = address type not supported |
1051 | * reserved (1 byte) = x00 |
1052 | * address type (1 byte) |
1053 | * 1 = IPv4 |
1054 | * 3 = domainname (first byte has length, no terminating null) |
1055 | * 4 = IPv6 |
1056 | * server bound address (variable) |
1057 | * server bound port (2 bytes) [network order] |
1058 | */ |
7983f47e |
1059 | char data[5]; |
1060 | int len; |
1061 | |
1062 | /* First 5 bytes of packet are enough to tell its length. */ |
1063 | if (bufchain_size(&p->pending_input_data) < 5) |
1064 | return 1; /* not got anything yet */ |
6971bbe7 |
1065 | |
1066 | /* get the response */ |
7983f47e |
1067 | bufchain_fetch(&p->pending_input_data, data, 5); |
6971bbe7 |
1068 | |
1069 | if (data[0] != 5) { |
7983f47e |
1070 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number", |
6971bbe7 |
1071 | PROXY_ERROR_GENERAL, 0); |
1072 | return 1; |
1073 | } |
1074 | |
1075 | if (data[1] != 0) { |
7983f47e |
1076 | char buf[256]; |
1077 | |
1078 | strcpy(buf, "Proxy error: "); |
6971bbe7 |
1079 | |
1080 | switch (data[1]) { |
7983f47e |
1081 | case 1: strcat(buf, "General SOCKS server failure"); break; |
1082 | case 2: strcat(buf, "Connection not allowed by ruleset"); break; |
1083 | case 3: strcat(buf, "Network unreachable"); break; |
1084 | case 4: strcat(buf, "Host unreachable"); break; |
1085 | case 5: strcat(buf, "Connection refused"); break; |
1086 | case 6: strcat(buf, "TTL expired"); break; |
1087 | case 7: strcat(buf, "Command not supported"); break; |
1088 | case 8: strcat(buf, "Address type not supported"); break; |
1089 | default: sprintf(buf+strlen(buf), |
1090 | "Unrecognised SOCKS error code %d", |
1091 | data[1]); |
6971bbe7 |
1092 | break; |
1093 | } |
7983f47e |
1094 | plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); |
1095 | |
1096 | return 1; |
1097 | } |
6971bbe7 |
1098 | |
7983f47e |
1099 | /* |
1100 | * Eat the rest of the reply packet. |
1101 | */ |
1102 | len = 6; /* first 4 bytes, last 2 */ |
1103 | switch (data[3]) { |
1104 | case 1: len += 4; break; /* IPv4 address */ |
1105 | case 4: len += 16; break;/* IPv6 address */ |
1106 | case 3: len += (unsigned char)data[4]; break; /* domain name */ |
1107 | default: |
1108 | plug_closing(p->plug, "Proxy error: SOCKS proxy returned " |
1109 | "unrecognised address format", |
1110 | PROXY_ERROR_GENERAL, 0); |
6971bbe7 |
1111 | return 1; |
1112 | } |
7983f47e |
1113 | if (bufchain_size(&p->pending_input_data) < len) |
1114 | return 1; /* not got whole reply yet */ |
1115 | bufchain_consume(&p->pending_input_data, len); |
6971bbe7 |
1116 | |
1117 | /* we're done */ |
1118 | proxy_activate(p); |
6971bbe7 |
1119 | return 1; |
1120 | } |
1121 | |
1122 | if (p->state == 4) { |
1123 | /* TODO: Handle GSSAPI authentication */ |
2192a8e4 |
1124 | plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication", |
6971bbe7 |
1125 | PROXY_ERROR_GENERAL, 0); |
1126 | return 1; |
1127 | } |
1128 | |
1129 | if (p->state == 5) { |
e8fa8f62 |
1130 | if (p->cfg.proxy_username[0] || p->cfg.proxy_password[0]) { |
aab91a3e |
1131 | char userpwbuf[514]; |
1132 | int ulen, plen; |
e8fa8f62 |
1133 | ulen = strlen(p->cfg.proxy_username); |
aab91a3e |
1134 | if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1; |
e8fa8f62 |
1135 | plen = strlen(p->cfg.proxy_password); |
aab91a3e |
1136 | if (plen > 255) plen = 255; if (plen < 1) plen = 1; |
1137 | userpwbuf[0] = 1; /* version number of subnegotiation */ |
1138 | userpwbuf[1] = ulen; |
e8fa8f62 |
1139 | memcpy(userpwbuf+2, p->cfg.proxy_username, ulen); |
aab91a3e |
1140 | userpwbuf[ulen+2] = plen; |
e8fa8f62 |
1141 | memcpy(userpwbuf+ulen+3, p->cfg.proxy_password, plen); |
aab91a3e |
1142 | sk_write(p->sub_socket, userpwbuf, ulen + plen + 3); |
1143 | p->state = 7; |
1144 | } else |
2192a8e4 |
1145 | plug_closing(p->plug, "Proxy error: Server chose " |
aab91a3e |
1146 | "username/password authentication but we " |
1147 | "didn't offer it!", |
6971bbe7 |
1148 | PROXY_ERROR_GENERAL, 0); |
1149 | return 1; |
1150 | } |
1151 | |
1152 | if (p->state == 6) { |
1153 | /* TODO: Handle CHAP authentication */ |
2192a8e4 |
1154 | plug_closing(p->plug, "Proxy error: We don't support CHAP authentication", |
6971bbe7 |
1155 | PROXY_ERROR_GENERAL, 0); |
1156 | return 1; |
1157 | } |
aab91a3e |
1158 | |
6971bbe7 |
1159 | } |
1160 | |
2192a8e4 |
1161 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
6971bbe7 |
1162 | PROXY_ERROR_UNEXPECTED, 0); |
1163 | return 1; |
8eebd221 |
1164 | } |
1165 | |
1166 | /* ---------------------------------------------------------------------- |
0e8f4cda |
1167 | * `Telnet' proxy type. |
8eebd221 |
1168 | * |
1169 | * (This is for ad-hoc proxies where you connect to the proxy's |
1170 | * telnet port and send a command such as `connect host port'. The |
1171 | * command is configurable, since this proxy type is typically not |
1172 | * standardised or at all well-defined.) |
1173 | */ |
1174 | |
0f0a2507 |
1175 | char *format_telnet_command(SockAddr addr, int port, const Config *cfg) |
8eebd221 |
1176 | { |
0f0a2507 |
1177 | char *ret = NULL; |
1178 | int retlen = 0, retsize = 0; |
1179 | int so = 0, eo = 0; |
1180 | #define ENSURE(n) do { \ |
1181 | if (retsize < retlen + n) { \ |
1182 | retsize = retlen + n + 512; \ |
1183 | ret = sresize(ret, retsize, char); \ |
1184 | } \ |
1185 | } while (0) |
1186 | |
1187 | /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, |
1188 | * %%, %host, %port, %user, and %pass |
1189 | */ |
0e8f4cda |
1190 | |
0f0a2507 |
1191 | while (cfg->proxy_telnet_command[eo] != 0) { |
0e8f4cda |
1192 | |
0f0a2507 |
1193 | /* scan forward until we hit end-of-line, |
1194 | * or an escape character (\ or %) */ |
1195 | while (cfg->proxy_telnet_command[eo] != 0 && |
1196 | cfg->proxy_telnet_command[eo] != '%' && |
1197 | cfg->proxy_telnet_command[eo] != '\\') eo++; |
0e8f4cda |
1198 | |
0f0a2507 |
1199 | /* if we hit eol, break out of our escaping loop */ |
1200 | if (cfg->proxy_telnet_command[eo] == 0) break; |
0e8f4cda |
1201 | |
0f0a2507 |
1202 | /* if there was any unescaped text before the escape |
1203 | * character, send that now */ |
1204 | if (eo != so) { |
1205 | ENSURE(eo - so); |
1206 | memcpy(ret + retlen, cfg->proxy_telnet_command + so, eo - so); |
1207 | retlen += eo - so; |
1208 | } |
0e8f4cda |
1209 | |
0f0a2507 |
1210 | so = eo++; |
0e8f4cda |
1211 | |
0f0a2507 |
1212 | /* if the escape character was the last character of |
1213 | * the line, we'll just stop and send it. */ |
1214 | if (cfg->proxy_telnet_command[eo] == 0) break; |
0e8f4cda |
1215 | |
0f0a2507 |
1216 | if (cfg->proxy_telnet_command[so] == '\\') { |
0e8f4cda |
1217 | |
0f0a2507 |
1218 | /* we recognize \\, \%, \r, \n, \t, \x??. |
1219 | * anything else, we just send unescaped (including the \). |
1220 | */ |
0e8f4cda |
1221 | |
0f0a2507 |
1222 | switch (cfg->proxy_telnet_command[eo]) { |
1223 | |
1224 | case '\\': |
1225 | ENSURE(1); |
1226 | ret[retlen++] = '\\'; |
1227 | eo++; |
1228 | break; |
1229 | |
1230 | case '%': |
1231 | ENSURE(1); |
1232 | ret[retlen++] = '%'; |
1233 | eo++; |
1234 | break; |
1235 | |
1236 | case 'r': |
1237 | ENSURE(1); |
1238 | ret[retlen++] = '\r'; |
1239 | eo++; |
1240 | break; |
1241 | |
1242 | case 'n': |
1243 | ENSURE(1); |
1244 | ret[retlen++] = '\n'; |
1245 | eo++; |
1246 | break; |
1247 | |
1248 | case 't': |
1249 | ENSURE(1); |
1250 | ret[retlen++] = '\t'; |
1251 | eo++; |
1252 | break; |
1253 | |
1254 | case 'x': |
1255 | case 'X': |
1256 | { |
0e8f4cda |
1257 | /* escaped hexadecimal value (ie. \xff) */ |
1258 | unsigned char v = 0; |
1259 | int i = 0; |
1260 | |
1261 | for (;;) { |
1262 | eo++; |
0f0a2507 |
1263 | if (cfg->proxy_telnet_command[eo] >= '0' && |
1264 | cfg->proxy_telnet_command[eo] <= '9') |
1265 | v += cfg->proxy_telnet_command[eo] - '0'; |
1266 | else if (cfg->proxy_telnet_command[eo] >= 'a' && |
1267 | cfg->proxy_telnet_command[eo] <= 'f') |
1268 | v += cfg->proxy_telnet_command[eo] - 'a' + 10; |
1269 | else if (cfg->proxy_telnet_command[eo] >= 'A' && |
1270 | cfg->proxy_telnet_command[eo] <= 'F') |
1271 | v += cfg->proxy_telnet_command[eo] - 'A' + 10; |
0e8f4cda |
1272 | else { |
1273 | /* non hex character, so we abort and just |
1274 | * send the whole thing unescaped (including \x) |
1275 | */ |
0f0a2507 |
1276 | ENSURE(1); |
1277 | ret[retlen++] = '\\'; |
0e8f4cda |
1278 | eo = so + 1; |
1279 | break; |
1280 | } |
1281 | |
1282 | /* we only extract two hex characters */ |
1283 | if (i == 1) { |
0f0a2507 |
1284 | ENSURE(1); |
1285 | ret[retlen++] = v; |
0e8f4cda |
1286 | eo++; |
1287 | break; |
1288 | } |
1289 | |
1290 | i++; |
1291 | v <<= 4; |
1292 | } |
0e8f4cda |
1293 | } |
0f0a2507 |
1294 | break; |
0e8f4cda |
1295 | |
0f0a2507 |
1296 | default: |
1297 | ENSURE(2); |
1298 | memcpy(ret+retlen, cfg->proxy_telnet_command + so, 2); |
1299 | retlen += 2; |
1300 | eo++; |
1301 | break; |
0e8f4cda |
1302 | } |
0f0a2507 |
1303 | } else { |
0e8f4cda |
1304 | |
0f0a2507 |
1305 | /* % escape. we recognize %%, %host, %port, %user, %pass. |
1306 | * anything else, we just send unescaped (including the %). |
1307 | */ |
0e8f4cda |
1308 | |
0f0a2507 |
1309 | if (cfg->proxy_telnet_command[eo] == '%') { |
1310 | ENSURE(1); |
1311 | ret[retlen++] = '%'; |
1312 | eo++; |
1313 | } |
1314 | else if (strnicmp(cfg->proxy_telnet_command + eo, |
1315 | "host", 4) == 0) { |
1316 | char dest[512]; |
1317 | int destlen; |
1318 | sk_getaddr(addr, dest, lenof(dest)); |
1319 | destlen = strlen(dest); |
1320 | ENSURE(destlen); |
1321 | memcpy(ret+retlen, dest, destlen); |
1322 | retlen += destlen; |
1323 | eo += 4; |
1324 | } |
1325 | else if (strnicmp(cfg->proxy_telnet_command + eo, |
1326 | "port", 4) == 0) { |
1327 | char portstr[8], portlen; |
1328 | portlen = sprintf(portstr, "%i", port); |
1329 | ENSURE(portlen); |
1330 | memcpy(ret + retlen, portstr, portlen); |
1331 | retlen += portlen; |
1332 | eo += 4; |
1333 | } |
1334 | else if (strnicmp(cfg->proxy_telnet_command + eo, |
1335 | "user", 4) == 0) { |
1336 | int userlen = strlen(cfg->proxy_username); |
1337 | ENSURE(userlen); |
1338 | memcpy(ret+retlen, cfg->proxy_username, userlen); |
1339 | retlen += userlen; |
1340 | eo += 4; |
1341 | } |
1342 | else if (strnicmp(cfg->proxy_telnet_command + eo, |
1343 | "pass", 4) == 0) { |
1344 | int passlen = strlen(cfg->proxy_password); |
1345 | ENSURE(passlen); |
1346 | memcpy(ret+retlen, cfg->proxy_password, passlen); |
1347 | retlen += passlen; |
1348 | eo += 4; |
1349 | } |
1350 | else { |
1351 | /* we don't escape this, so send the % now, and |
1352 | * don't advance eo, so that we'll consider the |
1353 | * text immediately following the % as unescaped. |
1354 | */ |
1355 | ENSURE(1); |
1356 | ret[retlen++] = '%'; |
1357 | } |
0e8f4cda |
1358 | } |
1359 | |
0f0a2507 |
1360 | /* resume scanning for additional escapes after this one. */ |
1361 | so = eo; |
1362 | } |
1363 | |
1364 | /* if there is any unescaped text at the end of the line, send it */ |
1365 | if (eo != so) { |
1366 | ENSURE(eo - so); |
1367 | memcpy(ret + retlen, cfg->proxy_telnet_command + so, eo - so); |
1368 | retlen += eo - so; |
1369 | } |
1370 | |
1371 | ENSURE(1); |
1372 | ret[retlen] = '\0'; |
1373 | return ret; |
1374 | |
1375 | #undef ENSURE |
1376 | } |
1377 | |
1378 | int proxy_telnet_negotiate (Proxy_Socket p, int change) |
1379 | { |
1380 | if (p->state == PROXY_CHANGE_NEW) { |
1381 | char *formatted_cmd; |
1382 | |
1383 | formatted_cmd = format_telnet_command(p->remote_addr, p->remote_port, |
1384 | &p->cfg); |
1385 | |
1386 | sk_write(p->sub_socket, formatted_cmd, strlen(formatted_cmd)); |
1387 | sfree(formatted_cmd); |
1388 | |
0e8f4cda |
1389 | p->state = 1; |
0e8f4cda |
1390 | return 0; |
1391 | } |
1392 | |
1393 | if (change == PROXY_CHANGE_CLOSING) { |
1394 | /* if our proxy negotiation process involves closing and opening |
1395 | * new sockets, then we would want to intercept this closing |
1396 | * callback when we were expecting it. if we aren't anticipating |
1397 | * a socket close, then some error must have occurred. we'll |
1398 | * just pass those errors up to the backend. |
1399 | */ |
1400 | return plug_closing(p->plug, p->closing_error_msg, |
1401 | p->closing_error_code, |
1402 | p->closing_calling_back); |
1403 | } |
1404 | |
1405 | if (change == PROXY_CHANGE_SENT) { |
1406 | /* some (or all) of what we wrote to the proxy was sent. |
1407 | * we don't do anything new, however, until we receive the |
1408 | * proxy's response. we might want to set a timer so we can |
1409 | * timeout the proxy negotiation after a while... |
1410 | */ |
1411 | return 0; |
1412 | } |
1413 | |
1414 | if (change == PROXY_CHANGE_ACCEPTING) { |
1415 | /* we should _never_ see this, as we are using our socket to |
1416 | * connect to a proxy, not accepting inbound connections. |
1417 | * what should we do? close the socket with an appropriate |
1418 | * error message? |
1419 | */ |
1420 | return plug_accepting(p->plug, p->accepting_sock); |
1421 | } |
1422 | |
1423 | if (change == PROXY_CHANGE_RECEIVE) { |
1424 | /* we have received data from the underlying socket, which |
1425 | * we'll need to parse, process, and respond to appropriately. |
1426 | */ |
1427 | |
1428 | /* we're done */ |
1429 | proxy_activate(p); |
1430 | /* proxy activate will have dealt with |
1431 | * whatever is left of the buffer */ |
1432 | return 1; |
1433 | } |
1434 | |
2192a8e4 |
1435 | plug_closing(p->plug, "Proxy error: Unexpected proxy error", |
0e8f4cda |
1436 | PROXY_ERROR_UNEXPECTED, 0); |
6971bbe7 |
1437 | return 1; |
8eebd221 |
1438 | } |