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