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