| blob | 7a479132379ee8499e3e9234438830f7f2c27835 |
1 /*\r
2 * Network proxy abstraction in PuTTY\r
3 *\r
4 * A proxy layer, if necessary, wedges itself between the network\r
5 * code and the higher level backend.\r
6 */\r
7 \r
8 #include <assert.h>\r
9 #include <ctype.h>\r
10 #include <string.h>\r
11 \r
12 #define DEFINE_PLUG_METHOD_MACROS\r
13 #include "putty.h"\r
14 #include "network.h"\r
15 #include "proxy.h"\r
16 \r
17 #define do_proxy_dns(conf) \\r
18 (conf_get_int(conf, CONF_proxy_dns) == FORCE_ON || \\r
19 (conf_get_int(conf, CONF_proxy_dns) == AUTO && \\r
20 conf_get_int(conf, CONF_proxy_type) != PROXY_SOCKS4))\r
21 \r
22 /*\r
23 * Call this when proxy negotiation is complete, so that this\r
24 * socket can begin working normally.\r
25 */\r
26 void proxy_activate (Proxy_Socket p)\r
27 {\r
28 void *data;\r
29 int len;\r
30 long output_before, output_after;\r
31 \r
32 p->state = PROXY_STATE_ACTIVE;\r
33 \r
34 /* we want to ignore new receive events until we have sent\r
35 * all of our buffered receive data.\r
36 */\r
37 sk_set_frozen(p->sub_socket, 1);\r
38 \r
39 /* how many bytes of output have we buffered? */\r
40 output_before = bufchain_size(&p->pending_oob_output_data) +\r
41 bufchain_size(&p->pending_output_data);\r
42 /* and keep track of how many bytes do not get sent. */\r
43 output_after = 0;\r
44 \r
45 /* send buffered OOB writes */\r
46 while (bufchain_size(&p->pending_oob_output_data) > 0) {\r
47 bufchain_prefix(&p->pending_oob_output_data, &data, &len);\r
48 output_after += sk_write_oob(p->sub_socket, data, len);\r
49 bufchain_consume(&p->pending_oob_output_data, len);\r
50 }\r
51 \r
52 /* send buffered normal writes */\r
53 while (bufchain_size(&p->pending_output_data) > 0) {\r
54 bufchain_prefix(&p->pending_output_data, &data, &len);\r
55 output_after += sk_write(p->sub_socket, data, len);\r
56 bufchain_consume(&p->pending_output_data, len);\r
57 }\r
58 \r
59 /* if we managed to send any data, let the higher levels know. */\r
60 if (output_after < output_before)\r
61 plug_sent(p->plug, output_after);\r
62 \r
63 /* if we were asked to flush the output during\r
64 * the proxy negotiation process, do so now.\r
65 */\r
66 if (p->pending_flush) sk_flush(p->sub_socket);\r
67 \r
68 /* if we have a pending EOF to send, send it */\r
69 if (p->pending_eof) sk_write_eof(p->sub_socket);\r
70 \r
71 /* if the backend wanted the socket unfrozen, try to unfreeze.\r
72 * our set_frozen handler will flush buffered receive data before\r
73 * unfreezing the actual underlying socket.\r
74 */\r
75 if (!p->freeze)\r
76 sk_set_frozen((Socket)p, 0);\r
77 }\r
78 \r
79 /* basic proxy socket functions */\r
80 \r
81 static Plug sk_proxy_plug (Socket s, Plug p)\r
82 {\r
83 Proxy_Socket ps = (Proxy_Socket) s;\r
84 Plug ret = ps->plug;\r
85 if (p)\r
86 ps->plug = p;\r
87 return ret;\r
88 }\r
89 \r
90 static void sk_proxy_close (Socket s)\r
91 {\r
92 Proxy_Socket ps = (Proxy_Socket) s;\r
93 \r
94 sk_close(ps->sub_socket);\r
95 sk_addr_free(ps->remote_addr);\r
96 sfree(ps);\r
97 }\r
98 \r
99 static int sk_proxy_write (Socket s, const char *data, int len)\r
100 {\r
101 Proxy_Socket ps = (Proxy_Socket) s;\r
102 \r
103 if (ps->state != PROXY_STATE_ACTIVE) {\r
104 bufchain_add(&ps->pending_output_data, data, len);\r
105 return bufchain_size(&ps->pending_output_data);\r
106 }\r
107 return sk_write(ps->sub_socket, data, len);\r
108 }\r
109 \r
110 static int sk_proxy_write_oob (Socket s, const char *data, int len)\r
111 {\r
112 Proxy_Socket ps = (Proxy_Socket) s;\r
113 \r
114 if (ps->state != PROXY_STATE_ACTIVE) {\r
115 bufchain_clear(&ps->pending_output_data);\r
116 bufchain_clear(&ps->pending_oob_output_data);\r
117 bufchain_add(&ps->pending_oob_output_data, data, len);\r
118 return len;\r
119 }\r
120 return sk_write_oob(ps->sub_socket, data, len);\r
121 }\r
122 \r
123 static void sk_proxy_write_eof (Socket s)\r
124 {\r
125 Proxy_Socket ps = (Proxy_Socket) s;\r
126 \r
127 if (ps->state != PROXY_STATE_ACTIVE) {\r
128 ps->pending_eof = 1;\r
129 return;\r
130 }\r
131 sk_write_eof(ps->sub_socket);\r
132 }\r
133 \r
134 static void sk_proxy_flush (Socket s)\r
135 {\r
136 Proxy_Socket ps = (Proxy_Socket) s;\r
137 \r
138 if (ps->state != PROXY_STATE_ACTIVE) {\r
139 ps->pending_flush = 1;\r
140 return;\r
141 }\r
142 sk_flush(ps->sub_socket);\r
143 }\r
144 \r
145 static void sk_proxy_set_frozen (Socket s, int is_frozen)\r
146 {\r
147 Proxy_Socket ps = (Proxy_Socket) s;\r
148 \r
149 if (ps->state != PROXY_STATE_ACTIVE) {\r
150 ps->freeze = is_frozen;\r
151 return;\r
152 }\r
153 \r
154 /* handle any remaining buffered recv data first */\r
155 if (bufchain_size(&ps->pending_input_data) > 0) {\r
156 ps->freeze = is_frozen;\r
157 \r
158 /* loop while we still have buffered data, and while we are\r
159 * unfrozen. the plug_receive call in the loop could result \r
160 * in a call back into this function refreezing the socket, \r
161 * so we have to check each time.\r
162 */\r
163 while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) {\r
164 void *data;\r
165 char databuf[512];\r
166 int len;\r
167 bufchain_prefix(&ps->pending_input_data, &data, &len);\r
168 if (len > lenof(databuf))\r
169 len = lenof(databuf);\r
170 memcpy(databuf, data, len);\r
171 bufchain_consume(&ps->pending_input_data, len);\r
172 plug_receive(ps->plug, 0, databuf, len);\r
173 }\r
174 \r
175 /* if we're still frozen, we'll have to wait for another\r
176 * call from the backend to finish unbuffering the data.\r
177 */\r
178 if (ps->freeze) return;\r
179 }\r
180 \r
181 sk_set_frozen(ps->sub_socket, is_frozen);\r
182 }\r
183 \r
184 static const char * sk_proxy_socket_error (Socket s)\r
185 {\r
186 Proxy_Socket ps = (Proxy_Socket) s;\r
187 if (ps->error != NULL || ps->sub_socket == NULL) {\r
188 return ps->error;\r
189 }\r
190 return sk_socket_error(ps->sub_socket);\r
191 }\r
192 \r
193 /* basic proxy plug functions */\r
194 \r
195 static void plug_proxy_log(Plug plug, int type, SockAddr addr, int port,\r
196 const char *error_msg, int error_code)\r
197 {\r
198 Proxy_Plug pp = (Proxy_Plug) plug;\r
199 Proxy_Socket ps = pp->proxy_socket;\r
200 \r
201 plug_log(ps->plug, type, addr, port, error_msg, error_code);\r
202 }\r
203 \r
204 static int plug_proxy_closing (Plug p, const char *error_msg,\r
205 int error_code, int calling_back)\r
206 {\r
207 Proxy_Plug pp = (Proxy_Plug) p;\r
208 Proxy_Socket ps = pp->proxy_socket;\r
209 \r
210 if (ps->state != PROXY_STATE_ACTIVE) {\r
211 ps->closing_error_msg = error_msg;\r
212 ps->closing_error_code = error_code;\r
213 ps->closing_calling_back = calling_back;\r
214 return ps->negotiate(ps, PROXY_CHANGE_CLOSING);\r
215 }\r
216 return plug_closing(ps->plug, error_msg,\r
217 error_code, calling_back);\r
218 }\r
219 \r
220 static int plug_proxy_receive (Plug p, int urgent, char *data, int len)\r
221 {\r
222 Proxy_Plug pp = (Proxy_Plug) p;\r
223 Proxy_Socket ps = pp->proxy_socket;\r
224 \r
225 if (ps->state != PROXY_STATE_ACTIVE) {\r
226 /* we will lose the urgentness of this data, but since most,\r
227 * if not all, of this data will be consumed by the negotiation\r
228 * process, hopefully it won't affect the protocol above us\r
229 */\r
230 bufchain_add(&ps->pending_input_data, data, len);\r
231 ps->receive_urgent = urgent;\r
232 ps->receive_data = data;\r
233 ps->receive_len = len;\r
234 return ps->negotiate(ps, PROXY_CHANGE_RECEIVE);\r
235 }\r
236 return plug_receive(ps->plug, urgent, data, len);\r
237 }\r
238 \r
239 static void plug_proxy_sent (Plug p, int bufsize)\r
240 {\r
241 Proxy_Plug pp = (Proxy_Plug) p;\r
242 Proxy_Socket ps = pp->proxy_socket;\r
243 \r
244 if (ps->state != PROXY_STATE_ACTIVE) {\r
245 ps->sent_bufsize = bufsize;\r
246 ps->negotiate(ps, PROXY_CHANGE_SENT);\r
247 return;\r
248 }\r
249 plug_sent(ps->plug, bufsize);\r
250 }\r
251 \r
252 static int plug_proxy_accepting(Plug p,\r
253 accept_fn_t constructor, accept_ctx_t ctx)\r
254 {\r
255 Proxy_Plug pp = (Proxy_Plug) p;\r
256 Proxy_Socket ps = pp->proxy_socket;\r
257 \r
258 if (ps->state != PROXY_STATE_ACTIVE) {\r
259 ps->accepting_constructor = constructor;\r
260 ps->accepting_ctx = ctx;\r
261 return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING);\r
262 }\r
263 return plug_accepting(ps->plug, constructor, ctx);\r
264 }\r
265 \r
266 /*\r
267 * This function can accept a NULL pointer as `addr', in which case\r
268 * it will only check the host name.\r
269 */\r
270 int proxy_for_destination (SockAddr addr, const char *hostname,\r
271 int port, Conf *conf)\r
272 {\r
273 int s = 0, e = 0;\r
274 char hostip[64];\r
275 int hostip_len, hostname_len;\r
276 const char *exclude_list;\r
277 \r
278 /*\r
279 * Special local connections such as Unix-domain sockets\r
280 * unconditionally cannot be proxied, even in proxy-localhost\r
281 * mode. There just isn't any way to ask any known proxy type for\r
282 * them.\r
283 */\r
284 if (addr && sk_address_is_special_local(addr))\r
285 return 0; /* do not proxy */\r
286 \r
287 /*\r
288 * Check the host name and IP against the hard-coded\r
289 * representations of `localhost'.\r
290 */\r
291 if (!conf_get_int(conf, CONF_even_proxy_localhost) &&\r
292 (sk_hostname_is_local(hostname) ||\r
293 (addr && sk_address_is_local(addr))))\r
294 return 0; /* do not proxy */\r
295 \r
296 /* we want a string representation of the IP address for comparisons */\r
297 if (addr) {\r
298 sk_getaddr(addr, hostip, 64);\r
299 hostip_len = strlen(hostip);\r
300 } else\r
301 hostip_len = 0; /* placate gcc; shouldn't be required */\r
302 \r
303 hostname_len = strlen(hostname);\r
304 \r
305 exclude_list = conf_get_str(conf, CONF_proxy_exclude_list);\r
306 \r
307 /* now parse the exclude list, and see if either our IP\r
308 * or hostname matches anything in it.\r
309 */\r
310 \r
311 while (exclude_list[s]) {\r
312 while (exclude_list[s] &&\r
313 (isspace((unsigned char)exclude_list[s]) ||\r
314 exclude_list[s] == ',')) s++;\r
315 \r
316 if (!exclude_list[s]) break;\r
317 \r
318 e = s;\r
319 \r
320 while (exclude_list[e] &&\r
321 (isalnum((unsigned char)exclude_list[e]) ||\r
322 exclude_list[e] == '-' ||\r
323 exclude_list[e] == '.' ||\r
324 exclude_list[e] == '*')) e++;\r
325 \r
326 if (exclude_list[s] == '*') {\r
327 /* wildcard at beginning of entry */\r
328 \r
329 if ((addr && strnicmp(hostip + hostip_len - (e - s - 1),\r
330 exclude_list + s + 1, e - s - 1) == 0) ||\r
331 strnicmp(hostname + hostname_len - (e - s - 1),\r
332 exclude_list + s + 1, e - s - 1) == 0)\r
333 return 0; /* IP/hostname range excluded. do not use proxy. */\r
334 \r
335 } else if (exclude_list[e-1] == '*') {\r
336 /* wildcard at end of entry */\r
337 \r
338 if ((addr && strnicmp(hostip, exclude_list + s, e - s - 1) == 0) ||\r
339 strnicmp(hostname, exclude_list + s, e - s - 1) == 0)\r
340 return 0; /* IP/hostname range excluded. do not use proxy. */\r
341 \r
342 } else {\r
343 /* no wildcard at either end, so let's try an absolute\r
344 * match (ie. a specific IP)\r
345 */\r
346 \r
347 if (addr && strnicmp(hostip, exclude_list + s, e - s) == 0)\r
348 return 0; /* IP/hostname excluded. do not use proxy. */\r
349 if (strnicmp(hostname, exclude_list + s, e - s) == 0)\r
350 return 0; /* IP/hostname excluded. do not use proxy. */\r
351 }\r
352 \r
353 s = e;\r
354 \r
355 /* Make sure we really have reached the next comma or end-of-string */\r
356 while (exclude_list[s] &&\r
357 !isspace((unsigned char)exclude_list[s]) &&\r
358 exclude_list[s] != ',') s++;\r
359 }\r
360 \r
361 /* no matches in the exclude list, so use the proxy */\r
362 return 1;\r
363 }\r
364 \r
365 SockAddr name_lookup(char *host, int port, char **canonicalname,\r
366 Conf *conf, int addressfamily)\r
367 {\r
368 if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE &&\r
369 do_proxy_dns(conf) &&\r
370 proxy_for_destination(NULL, host, port, conf)) {\r
371 *canonicalname = dupstr(host);\r
372 return sk_nonamelookup(host);\r
373 }\r
374 \r
375 return sk_namelookup(host, canonicalname, addressfamily);\r
376 }\r
377 \r
378 Socket new_connection(SockAddr addr, char *hostname,\r
379 int port, int privport,\r
380 int oobinline, int nodelay, int keepalive,\r
381 Plug plug, Conf *conf)\r
382 {\r
383 static const struct socket_function_table socket_fn_table = {\r
384 sk_proxy_plug,\r
385 sk_proxy_close,\r
386 sk_proxy_write,\r
387 sk_proxy_write_oob,\r
388 sk_proxy_write_eof,\r
389 sk_proxy_flush,\r
390 sk_proxy_set_frozen,\r
391 sk_proxy_socket_error\r
392 };\r
393 \r
394 static const struct plug_function_table plug_fn_table = {\r
395 plug_proxy_log,\r
396 plug_proxy_closing,\r
397 plug_proxy_receive,\r
398 plug_proxy_sent,\r
399 plug_proxy_accepting\r
400 };\r
401 \r
402 if (conf_get_int(conf, CONF_proxy_type) != PROXY_NONE &&\r
403 proxy_for_destination(addr, hostname, port, conf))\r
404 {\r
405 Proxy_Socket ret;\r
406 Proxy_Plug pplug;\r
407 SockAddr proxy_addr;\r
408 char *proxy_canonical_name;\r
409 Socket sret;\r
410 int type;\r
411 \r
412 if ((sret = platform_new_connection(addr, hostname, port, privport,\r
413 oobinline, nodelay, keepalive,\r
414 plug, conf)) !=\r
415 NULL)\r
416 return sret;\r
417 \r
418 ret = snew(struct Socket_proxy_tag);\r
419 ret->fn = &socket_fn_table;\r
420 ret->conf = conf_copy(conf);\r
421 ret->plug = plug;\r
422 ret->remote_addr = addr; /* will need to be freed on close */\r
423 ret->remote_port = port;\r
424 \r
425 ret->error = NULL;\r
426 ret->pending_flush = 0;\r
427 ret->pending_eof = 0;\r
428 ret->freeze = 0;\r
429 \r
430 bufchain_init(&ret->pending_input_data);\r
431 bufchain_init(&ret->pending_output_data);\r
432 bufchain_init(&ret->pending_oob_output_data);\r
433 \r
434 ret->sub_socket = NULL;\r
435 ret->state = PROXY_STATE_NEW;\r
436 ret->negotiate = NULL;\r
437 \r
438 type = conf_get_int(conf, CONF_proxy_type);\r
439 if (type == PROXY_HTTP) {\r
440 ret->negotiate = proxy_http_negotiate;\r
441 } else if (type == PROXY_SOCKS4) {\r
442 ret->negotiate = proxy_socks4_negotiate;\r
443 } else if (type == PROXY_SOCKS5) {\r
444 ret->negotiate = proxy_socks5_negotiate;\r
445 } else if (type == PROXY_TELNET) {\r
446 ret->negotiate = proxy_telnet_negotiate;\r
447 } else {\r
448 ret->error = "Proxy error: Unknown proxy method";\r
449 return (Socket) ret;\r
450 }\r
451 \r
452 /* create the proxy plug to map calls from the actual\r
453 * socket into our proxy socket layer */\r
454 pplug = snew(struct Plug_proxy_tag);\r
455 pplug->fn = &plug_fn_table;\r
456 pplug->proxy_socket = ret;\r
457 \r
458 /* look-up proxy */\r
459 proxy_addr = sk_namelookup(conf_get_str(conf, CONF_proxy_host),\r
460 &proxy_canonical_name,\r
461 conf_get_int(conf, CONF_addressfamily));\r
462 if (sk_addr_error(proxy_addr) != NULL) {\r
463 ret->error = "Proxy error: Unable to resolve proxy host name";\r
464 sfree(pplug);\r
465 sk_addr_free(proxy_addr);\r
466 return (Socket)ret;\r
467 }\r
468 sfree(proxy_canonical_name);\r
469 \r
470 /* create the actual socket we will be using,\r
471 * connected to our proxy server and port.\r
472 */\r
473 ret->sub_socket = sk_new(proxy_addr,\r
474 conf_get_int(conf, CONF_proxy_port),\r
475 privport, oobinline,\r
476 nodelay, keepalive, (Plug) pplug);\r
477 if (sk_socket_error(ret->sub_socket) != NULL)\r
478 return (Socket) ret;\r
479 \r
480 /* start the proxy negotiation process... */\r
481 sk_set_frozen(ret->sub_socket, 0);\r
482 ret->negotiate(ret, PROXY_CHANGE_NEW);\r
483 \r
484 return (Socket) ret;\r
485 }\r
486 \r
487 /* no proxy, so just return the direct socket */\r
488 return sk_new(addr, port, privport, oobinline, nodelay, keepalive, plug);\r
489 }\r
490 \r
491 Socket new_listener(char *srcaddr, int port, Plug plug, int local_host_only,\r
492 Conf *conf, int addressfamily)\r
493 {\r
494 /* TODO: SOCKS (and potentially others) support inbound\r
495 * TODO: connections via the proxy. support them.\r
496 */\r
497 \r
498 return sk_newlistener(srcaddr, port, plug, local_host_only, addressfamily);\r
499 }\r
500 \r
501 /* ----------------------------------------------------------------------\r
502 * HTTP CONNECT proxy type.\r
503 */\r
504 \r
505 static int get_line_end (char * data, int len)\r
506 {\r
507 int off = 0;\r
508 \r
509 while (off < len)\r
510 {\r
511 if (data[off] == '\n') {\r
512 /* we have a newline */\r
513 off++;\r
514 \r
515 /* is that the only thing on this line? */\r
516 if (off <= 2) return off;\r
517 \r
518 /* if not, then there is the possibility that this header\r
519 * continues onto the next line, if it starts with a space\r
520 * or a tab.\r
521 */\r
522 \r
523 if (off + 1 < len &&\r
524 data[off+1] != ' ' &&\r
525 data[off+1] != '\t') return off;\r
526 \r
527 /* the line does continue, so we have to keep going\r
528 * until we see an the header's "real" end of line.\r
529 */\r
530 off++;\r
531 }\r
532 \r
533 off++;\r
534 }\r
535 \r
536 return -1;\r
537 }\r
538 \r
539 int proxy_http_negotiate (Proxy_Socket p, int change)\r
540 {\r
541 if (p->state == PROXY_STATE_NEW) {\r
542 /* we are just beginning the proxy negotiate process,\r
543 * so we'll send off the initial bits of the request.\r
544 * for this proxy method, it's just a simple HTTP\r
545 * request\r
546 */\r
547 char *buf, dest[512];\r
548 char *username, *password;\r
549 \r
550 sk_getaddr(p->remote_addr, dest, lenof(dest));\r
551 \r
552 buf = dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",\r
553 dest, p->remote_port, dest, p->remote_port);\r
554 sk_write(p->sub_socket, buf, strlen(buf));\r
555 sfree(buf);\r
556 \r
557 username = conf_get_str(p->conf, CONF_proxy_username);\r
558 password = conf_get_str(p->conf, CONF_proxy_password);\r
559 if (username[0] || password[0]) {\r
560 char *buf, *buf2;\r
561 int i, j, len;\r
562 buf = dupprintf("%s:%s", username, password);\r
563 len = strlen(buf);\r
564 buf2 = snewn(len * 4 / 3 + 100, char);\r
565 sprintf(buf2, "Proxy-Authorization: Basic ");\r
566 for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4)\r
567 base64_encode_atom((unsigned char *)(buf+i),\r
568 (len-i > 3 ? 3 : len-i), buf2+j);\r
569 strcpy(buf2+j, "\r\n");\r
570 sk_write(p->sub_socket, buf2, strlen(buf2));\r
571 sfree(buf);\r
572 sfree(buf2);\r
573 }\r
574 \r
575 sk_write(p->sub_socket, "\r\n", 2);\r
576 \r
577 p->state = 1;\r
578 return 0;\r
579 }\r
580 \r
581 if (change == PROXY_CHANGE_CLOSING) {\r
582 /* if our proxy negotiation process involves closing and opening\r
583 * new sockets, then we would want to intercept this closing\r
584 * callback when we were expecting it. if we aren't anticipating\r
585 * a socket close, then some error must have occurred. we'll\r
586 * just pass those errors up to the backend.\r
587 */\r
588 return plug_closing(p->plug, p->closing_error_msg,\r
589 p->closing_error_code,\r
590 p->closing_calling_back);\r
591 }\r
592 \r
593 if (change == PROXY_CHANGE_SENT) {\r
594 /* some (or all) of what we wrote to the proxy was sent.\r
595 * we don't do anything new, however, until we receive the\r
596 * proxy's response. we might want to set a timer so we can\r
597 * timeout the proxy negotiation after a while...\r
598 */\r
599 return 0;\r
600 }\r
601 \r
602 if (change == PROXY_CHANGE_ACCEPTING) {\r
603 /* we should _never_ see this, as we are using our socket to\r
604 * connect to a proxy, not accepting inbound connections.\r
605 * what should we do? close the socket with an appropriate\r
606 * error message?\r
607 */\r
608 return plug_accepting(p->plug,\r
609 p->accepting_constructor, p->accepting_ctx);\r
610 }\r
611 \r
612 if (change == PROXY_CHANGE_RECEIVE) {\r
613 /* we have received data from the underlying socket, which\r
614 * we'll need to parse, process, and respond to appropriately.\r
615 */\r
616 \r
617 char *data, *datap;\r
618 int len;\r
619 int eol;\r
620 \r
621 if (p->state == 1) {\r
622 \r
623 int min_ver, maj_ver, status;\r
624 \r
625 /* get the status line */\r
626 len = bufchain_size(&p->pending_input_data);\r
627 assert(len > 0); /* or we wouldn't be here */\r
628 data = snewn(len+1, char);\r
629 bufchain_fetch(&p->pending_input_data, data, len);\r
630 /*\r
631 * We must NUL-terminate this data, because Windows\r
632 * sscanf appears to require a NUL at the end of the\r
633 * string because it strlens it _first_. Sigh.\r
634 */\r
635 data[len] = '\0';\r
636 \r
637 eol = get_line_end(data, len);\r
638 if (eol < 0) {\r
639 sfree(data);\r
640 return 1;\r
641 }\r
642 \r
643 status = -1;\r
644 /* We can't rely on whether the %n incremented the sscanf return */\r
645 if (sscanf((char *)data, "HTTP/%i.%i %n",\r
646 &maj_ver, &min_ver, &status) < 2 || status == -1) {\r
647 plug_closing(p->plug, "Proxy error: HTTP response was absent",\r
648 PROXY_ERROR_GENERAL, 0);\r
649 sfree(data);\r
650 return 1;\r
651 }\r
652 \r
653 /* remove the status line from the input buffer. */\r
654 bufchain_consume(&p->pending_input_data, eol);\r
655 if (data[status] != '2') {\r
656 /* error */\r
657 char *buf;\r
658 data[eol] = '\0';\r
659 while (eol > status &&\r
660 (data[eol-1] == '\r' || data[eol-1] == '\n'))\r
661 data[--eol] = '\0';\r
662 buf = dupprintf("Proxy error: %s", data+status);\r
663 plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);\r
664 sfree(buf);\r
665 sfree(data);\r
666 return 1;\r
667 }\r
668 \r
669 sfree(data);\r
670 \r
671 p->state = 2;\r
672 }\r
673 \r
674 if (p->state == 2) {\r
675 \r
676 /* get headers. we're done when we get a\r
677 * header of length 2, (ie. just "\r\n")\r
678 */\r
679 \r
680 len = bufchain_size(&p->pending_input_data);\r
681 assert(len > 0); /* or we wouldn't be here */\r
682 data = snewn(len, char);\r
683 datap = data;\r
684 bufchain_fetch(&p->pending_input_data, data, len);\r
685 \r
686 eol = get_line_end(datap, len);\r
687 if (eol < 0) {\r
688 sfree(data);\r
689 return 1;\r
690 }\r
691 while (eol > 2)\r
692 {\r
693 bufchain_consume(&p->pending_input_data, eol);\r
694 datap += eol;\r
695 len -= eol;\r
696 eol = get_line_end(datap, len);\r
697 }\r
698 \r
699 if (eol == 2) {\r
700 /* we're done */\r
701 bufchain_consume(&p->pending_input_data, 2);\r
702 proxy_activate(p);\r
703 /* proxy activate will have dealt with\r
704 * whatever is left of the buffer */\r
705 sfree(data);\r
706 return 1;\r
707 }\r
708 \r
709 sfree(data);\r
710 return 1;\r
711 }\r
712 }\r
713 \r
714 plug_closing(p->plug, "Proxy error: unexpected proxy error",\r
715 PROXY_ERROR_UNEXPECTED, 0);\r
716 return 1;\r
717 }\r
718 \r
719 /* ----------------------------------------------------------------------\r
720 * SOCKS proxy type.\r
721 */\r
722 \r
723 /* SOCKS version 4 */\r
724 int proxy_socks4_negotiate (Proxy_Socket p, int change)\r
725 {\r
726 if (p->state == PROXY_CHANGE_NEW) {\r
727 \r
728 /* request format:\r
729 * version number (1 byte) = 4\r
730 * command code (1 byte)\r
731 * 1 = CONNECT\r
732 * 2 = BIND\r
733 * dest. port (2 bytes) [network order]\r
734 * dest. address (4 bytes)\r
735 * user ID (variable length, null terminated string)\r
736 */\r
737 \r
738 int length, type, namelen;\r
739 char *command, addr[4], hostname[512];\r
740 char *username;\r
741 \r
742 type = sk_addrtype(p->remote_addr);\r
743 if (type == ADDRTYPE_IPV6) {\r
744 p->error = "Proxy error: SOCKS version 4 does not support IPv6";\r
745 return 1;\r
746 } else if (type == ADDRTYPE_IPV4) {\r
747 namelen = 0;\r
748 sk_addrcopy(p->remote_addr, addr);\r
749 } else { /* type == ADDRTYPE_NAME */\r
750 assert(type == ADDRTYPE_NAME);\r
751 sk_getaddr(p->remote_addr, hostname, lenof(hostname));\r
752 namelen = strlen(hostname) + 1; /* include the NUL */\r
753 addr[0] = addr[1] = addr[2] = 0;\r
754 addr[3] = 1;\r
755 }\r
756 \r
757 username = conf_get_str(p->conf, CONF_proxy_username);\r
758 length = strlen(username) + namelen + 9;\r
759 command = snewn(length, char);\r
760 strcpy(command + 8, username);\r
761 \r
762 command[0] = 4; /* version 4 */\r
763 command[1] = 1; /* CONNECT command */\r
764 \r
765 /* port */\r
766 command[2] = (char) (p->remote_port >> 8) & 0xff;\r
767 command[3] = (char) p->remote_port & 0xff;\r
768 \r
769 /* address */\r
770 memcpy(command + 4, addr, 4);\r
771 \r
772 /* hostname */\r
773 memcpy(command + 8 + strlen(username) + 1,\r
774 hostname, namelen);\r
775 \r
776 sk_write(p->sub_socket, command, length);\r
777 sfree(username);\r
778 sfree(command);\r
779 \r
780 p->state = 1;\r
781 return 0;\r
782 }\r
783 \r
784 if (change == PROXY_CHANGE_CLOSING) {\r
785 /* if our proxy negotiation process involves closing and opening\r
786 * new sockets, then we would want to intercept this closing\r
787 * callback when we were expecting it. if we aren't anticipating\r
788 * a socket close, then some error must have occurred. we'll\r
789 * just pass those errors up to the backend.\r
790 */\r
791 return plug_closing(p->plug, p->closing_error_msg,\r
792 p->closing_error_code,\r
793 p->closing_calling_back);\r
794 }\r
795 \r
796 if (change == PROXY_CHANGE_SENT) {\r
797 /* some (or all) of what we wrote to the proxy was sent.\r
798 * we don't do anything new, however, until we receive the\r
799 * proxy's response. we might want to set a timer so we can\r
800 * timeout the proxy negotiation after a while...\r
801 */\r
802 return 0;\r
803 }\r
804 \r
805 if (change == PROXY_CHANGE_ACCEPTING) {\r
806 /* we should _never_ see this, as we are using our socket to\r
807 * connect to a proxy, not accepting inbound connections.\r
808 * what should we do? close the socket with an appropriate\r
809 * error message?\r
810 */\r
811 return plug_accepting(p->plug,\r
812 p->accepting_constructor, p->accepting_ctx);\r
813 }\r
814 \r
815 if (change == PROXY_CHANGE_RECEIVE) {\r
816 /* we have received data from the underlying socket, which\r
817 * we'll need to parse, process, and respond to appropriately.\r
818 */\r
819 \r
820 if (p->state == 1) {\r
821 /* response format:\r
822 * version number (1 byte) = 4\r
823 * reply code (1 byte)\r
824 * 90 = request granted\r
825 * 91 = request rejected or failed\r
826 * 92 = request rejected due to lack of IDENTD on client\r
827 * 93 = request rejected due to difference in user ID \r
828 * (what we sent vs. what IDENTD said)\r
829 * dest. port (2 bytes)\r
830 * dest. address (4 bytes)\r
831 */\r
832 \r
833 char data[8];\r
834 \r
835 if (bufchain_size(&p->pending_input_data) < 8)\r
836 return 1; /* not got anything yet */\r
837 \r
838 /* get the response */\r
839 bufchain_fetch(&p->pending_input_data, data, 8);\r
840 \r
841 if (data[0] != 0) {\r
842 plug_closing(p->plug, "Proxy error: SOCKS proxy responded with "\r
843 "unexpected reply code version",\r
844 PROXY_ERROR_GENERAL, 0);\r
845 return 1;\r
846 }\r
847 \r
848 if (data[1] != 90) {\r
849 \r
850 switch (data[1]) {\r
851 case 92:\r
852 plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client",\r
853 PROXY_ERROR_GENERAL, 0);\r
854 break;\r
855 case 93:\r
856 plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree",\r
857 PROXY_ERROR_GENERAL, 0);\r
858 break;\r
859 case 91:\r
860 default:\r
861 plug_closing(p->plug, "Proxy error: Error while communicating with proxy",\r
862 PROXY_ERROR_GENERAL, 0);\r
863 break;\r
864 }\r
865 \r
866 return 1;\r
867 }\r
868 bufchain_consume(&p->pending_input_data, 8);\r
869 \r
870 /* we're done */\r
871 proxy_activate(p);\r
872 /* proxy activate will have dealt with\r
873 * whatever is left of the buffer */\r
874 return 1;\r
875 }\r
876 }\r
877 \r
878 plug_closing(p->plug, "Proxy error: unexpected proxy error",\r
879 PROXY_ERROR_UNEXPECTED, 0);\r
880 return 1;\r
881 }\r
882 \r
883 /* SOCKS version 5 */\r
884 int proxy_socks5_negotiate (Proxy_Socket p, int change)\r
885 {\r
886 if (p->state == PROXY_CHANGE_NEW) {\r
887 \r
888 /* initial command:\r
889 * version number (1 byte) = 5\r
890 * number of available authentication methods (1 byte)\r
891 * available authentication methods (1 byte * previous value)\r
892 * authentication methods:\r
893 * 0x00 = no authentication\r
894 * 0x01 = GSSAPI\r
895 * 0x02 = username/password\r
896 * 0x03 = CHAP\r
897 */\r
898 \r
899 char command[5];\r
900 char *username, *password;\r
901 int len;\r
902 \r
903 command[0] = 5; /* version 5 */\r
904 username = conf_get_str(p->conf, CONF_proxy_username);\r
905 password = conf_get_str(p->conf, CONF_proxy_password);\r
906 if (username[0] || password[0]) {\r
907 command[2] = 0x00; /* no authentication */\r
908 len = 3;\r
909 proxy_socks5_offerencryptedauth (command, &len);\r
910 command[len++] = 0x02; /* username/password */\r
911 command[1] = len - 2; /* Number of methods supported */\r
912 } else {\r
913 command[1] = 1; /* one methods supported: */\r
914 command[2] = 0x00; /* no authentication */\r
915 len = 3;\r
916 }\r
917 \r
918 sk_write(p->sub_socket, command, len);\r
919 \r
920 p->state = 1;\r
921 return 0;\r
922 }\r
923 \r
924 if (change == PROXY_CHANGE_CLOSING) {\r
925 /* if our proxy negotiation process involves closing and opening\r
926 * new sockets, then we would want to intercept this closing\r
927 * callback when we were expecting it. if we aren't anticipating\r
928 * a socket close, then some error must have occurred. we'll\r
929 * just pass those errors up to the backend.\r
930 */\r
931 return plug_closing(p->plug, p->closing_error_msg,\r
932 p->closing_error_code,\r
933 p->closing_calling_back);\r
934 }\r
935 \r
936 if (change == PROXY_CHANGE_SENT) {\r
937 /* some (or all) of what we wrote to the proxy was sent.\r
938 * we don't do anything new, however, until we receive the\r
939 * proxy's response. we might want to set a timer so we can\r
940 * timeout the proxy negotiation after a while...\r
941 */\r
942 return 0;\r
943 }\r
944 \r
945 if (change == PROXY_CHANGE_ACCEPTING) {\r
946 /* we should _never_ see this, as we are using our socket to\r
947 * connect to a proxy, not accepting inbound connections.\r
948 * what should we do? close the socket with an appropriate\r
949 * error message?\r
950 */\r
951 return plug_accepting(p->plug,\r
952 p->accepting_constructor, p->accepting_ctx);\r
953 }\r
954 \r
955 if (change == PROXY_CHANGE_RECEIVE) {\r
956 /* we have received data from the underlying socket, which\r
957 * we'll need to parse, process, and respond to appropriately.\r
958 */\r
959 \r
960 if (p->state == 1) {\r
961 \r
962 /* initial response:\r
963 * version number (1 byte) = 5\r
964 * authentication method (1 byte)\r
965 * authentication methods:\r
966 * 0x00 = no authentication\r
967 * 0x01 = GSSAPI\r
968 * 0x02 = username/password\r
969 * 0x03 = CHAP\r
970 * 0xff = no acceptable methods\r
971 */\r
972 char data[2];\r
973 \r
974 if (bufchain_size(&p->pending_input_data) < 2)\r
975 return 1; /* not got anything yet */\r
976 \r
977 /* get the response */\r
978 bufchain_fetch(&p->pending_input_data, data, 2);\r
979 \r
980 if (data[0] != 5) {\r
981 plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version",\r
982 PROXY_ERROR_GENERAL, 0);\r
983 return 1;\r
984 }\r
985 \r
986 if (data[1] == 0x00) p->state = 2; /* no authentication needed */\r
987 else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */\r
988 else if (data[1] == 0x02) p->state = 5; /* username/password authentication */\r
989 else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */\r
990 else {\r
991 plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication",\r
992 PROXY_ERROR_GENERAL, 0);\r
993 return 1;\r
994 }\r
995 bufchain_consume(&p->pending_input_data, 2);\r
996 }\r
997 \r
998 if (p->state == 7) {\r
999 \r
1000 /* password authentication reply format:\r
1001 * version number (1 bytes) = 1\r
1002 * reply code (1 byte)\r
1003 * 0 = succeeded\r
1004 * >0 = failed\r
1005 */\r
1006 char data[2];\r
1007 \r
1008 if (bufchain_size(&p->pending_input_data) < 2)\r
1009 return 1; /* not got anything yet */\r
1010 \r
1011 /* get the response */\r
1012 bufchain_fetch(&p->pending_input_data, data, 2);\r
1013 \r
1014 if (data[0] != 1) {\r
1015 plug_closing(p->plug, "Proxy error: SOCKS password "\r
1016 "subnegotiation contained wrong version number",\r
1017 PROXY_ERROR_GENERAL, 0);\r
1018 return 1;\r
1019 }\r
1020 \r
1021 if (data[1] != 0) {\r
1022 \r
1023 plug_closing(p->plug, "Proxy error: SOCKS proxy refused"\r
1024 " password authentication",\r
1025 PROXY_ERROR_GENERAL, 0);\r
1026 return 1;\r
1027 }\r
1028 \r
1029 bufchain_consume(&p->pending_input_data, 2);\r
1030 p->state = 2; /* now proceed as authenticated */\r
1031 }\r
1032 \r
1033 if (p->state == 8) {\r
1034 int ret;\r
1035 ret = proxy_socks5_handlechap(p);\r
1036 if (ret) return ret;\r
1037 }\r
1038 \r
1039 if (p->state == 2) {\r
1040 \r
1041 /* request format:\r
1042 * version number (1 byte) = 5\r
1043 * command code (1 byte)\r
1044 * 1 = CONNECT\r
1045 * 2 = BIND\r
1046 * 3 = UDP ASSOCIATE\r
1047 * reserved (1 byte) = 0x00\r
1048 * address type (1 byte)\r
1049 * 1 = IPv4\r
1050 * 3 = domainname (first byte has length, no terminating null)\r
1051 * 4 = IPv6\r
1052 * dest. address (variable)\r
1053 * dest. port (2 bytes) [network order]\r
1054 */\r
1055 \r
1056 char command[512];\r
1057 int len;\r
1058 int type;\r
1059 \r
1060 type = sk_addrtype(p->remote_addr);\r
1061 if (type == ADDRTYPE_IPV4) {\r
1062 len = 10; /* 4 hdr + 4 addr + 2 trailer */\r
1063 command[3] = 1; /* IPv4 */\r
1064 sk_addrcopy(p->remote_addr, command+4);\r
1065 } else if (type == ADDRTYPE_IPV6) {\r
1066 len = 22; /* 4 hdr + 16 addr + 2 trailer */\r
1067 command[3] = 4; /* IPv6 */\r
1068 sk_addrcopy(p->remote_addr, command+4);\r
1069 } else {\r
1070 assert(type == ADDRTYPE_NAME);\r
1071 command[3] = 3;\r
1072 sk_getaddr(p->remote_addr, command+5, 256);\r
1073 command[4] = strlen(command+5);\r
1074 len = 7 + command[4]; /* 4 hdr, 1 len, N addr, 2 trailer */\r
1075 }\r
1076 \r
1077 command[0] = 5; /* version 5 */\r
1078 command[1] = 1; /* CONNECT command */\r
1079 command[2] = 0x00;\r
1080 \r
1081 /* port */\r
1082 command[len-2] = (char) (p->remote_port >> 8) & 0xff;\r
1083 command[len-1] = (char) p->remote_port & 0xff;\r
1084 \r
1085 sk_write(p->sub_socket, command, len);\r
1086 \r
1087 p->state = 3;\r
1088 return 1;\r
1089 }\r
1090 \r
1091 if (p->state == 3) {\r
1092 \r
1093 /* reply format:\r
1094 * version number (1 bytes) = 5\r
1095 * reply code (1 byte)\r
1096 * 0 = succeeded\r
1097 * 1 = general SOCKS server failure\r
1098 * 2 = connection not allowed by ruleset\r
1099 * 3 = network unreachable\r
1100 * 4 = host unreachable\r
1101 * 5 = connection refused\r
1102 * 6 = TTL expired\r
1103 * 7 = command not supported\r
1104 * 8 = address type not supported\r
1105 * reserved (1 byte) = x00\r
1106 * address type (1 byte)\r
1107 * 1 = IPv4\r
1108 * 3 = domainname (first byte has length, no terminating null)\r
1109 * 4 = IPv6\r
1110 * server bound address (variable)\r
1111 * server bound port (2 bytes) [network order]\r
1112 */\r
1113 char data[5];\r
1114 int len;\r
1115 \r
1116 /* First 5 bytes of packet are enough to tell its length. */ \r
1117 if (bufchain_size(&p->pending_input_data) < 5)\r
1118 return 1; /* not got anything yet */\r
1119 \r
1120 /* get the response */\r
1121 bufchain_fetch(&p->pending_input_data, data, 5);\r
1122 \r
1123 if (data[0] != 5) {\r
1124 plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number",\r
1125 PROXY_ERROR_GENERAL, 0);\r
1126 return 1;\r
1127 }\r
1128 \r
1129 if (data[1] != 0) {\r
1130 char buf[256];\r
1131 \r
1132 strcpy(buf, "Proxy error: ");\r
1133 \r
1134 switch (data[1]) {\r
1135 case 1: strcat(buf, "General SOCKS server failure"); break;\r
1136 case 2: strcat(buf, "Connection not allowed by ruleset"); break;\r
1137 case 3: strcat(buf, "Network unreachable"); break;\r
1138 case 4: strcat(buf, "Host unreachable"); break;\r
1139 case 5: strcat(buf, "Connection refused"); break;\r
1140 case 6: strcat(buf, "TTL expired"); break;\r
1141 case 7: strcat(buf, "Command not supported"); break;\r
1142 case 8: strcat(buf, "Address type not supported"); break;\r
1143 default: sprintf(buf+strlen(buf),\r
1144 "Unrecognised SOCKS error code %d",\r
1145 data[1]);\r
1146 break;\r
1147 }\r
1148 plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0);\r
1149 \r
1150 return 1;\r
1151 }\r
1152 \r
1153 /*\r
1154 * Eat the rest of the reply packet.\r
1155 */\r
1156 len = 6; /* first 4 bytes, last 2 */\r
1157 switch (data[3]) {\r
1158 case 1: len += 4; break; /* IPv4 address */\r
1159 case 4: len += 16; break;/* IPv6 address */\r
1160 case 3: len += (unsigned char)data[4]; break; /* domain name */\r
1161 default:\r
1162 plug_closing(p->plug, "Proxy error: SOCKS proxy returned "\r
1163 "unrecognised address format",\r
1164 PROXY_ERROR_GENERAL, 0);\r
1165 return 1;\r
1166 }\r
1167 if (bufchain_size(&p->pending_input_data) < len)\r
1168 return 1; /* not got whole reply yet */\r
1169 bufchain_consume(&p->pending_input_data, len);\r
1170 \r
1171 /* we're done */\r
1172 proxy_activate(p);\r
1173 return 1;\r
1174 }\r
1175 \r
1176 if (p->state == 4) {\r
1177 /* TODO: Handle GSSAPI authentication */\r
1178 plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication",\r
1179 PROXY_ERROR_GENERAL, 0);\r
1180 return 1;\r
1181 }\r
1182 \r
1183 if (p->state == 5) {\r
1184 char *username = conf_get_str(p->conf, CONF_proxy_username);\r
1185 char *password = conf_get_str(p->conf, CONF_proxy_password);\r
1186 if (username[0] || password[0]) {\r
1187 char userpwbuf[255 + 255 + 3];\r
1188 int ulen, plen;\r
1189 ulen = strlen(username);\r
1190 if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1;\r
1191 plen = strlen(password);\r
1192 if (plen > 255) plen = 255; if (plen < 1) plen = 1;\r
1193 userpwbuf[0] = 1; /* version number of subnegotiation */\r
1194 userpwbuf[1] = ulen;\r
1195 memcpy(userpwbuf+2, username, ulen);\r
1196 userpwbuf[ulen+2] = plen;\r
1197 memcpy(userpwbuf+ulen+3, password, plen);\r
1198 sk_write(p->sub_socket, userpwbuf, ulen + plen + 3);\r
1199 p->state = 7;\r
1200 } else \r
1201 plug_closing(p->plug, "Proxy error: Server chose "\r
1202 "username/password authentication but we "\r
1203 "didn't offer it!",\r
1204 PROXY_ERROR_GENERAL, 0);\r
1205 return 1;\r
1206 }\r
1207 \r
1208 if (p->state == 6) {\r
1209 int ret;\r
1210 ret = proxy_socks5_selectchap(p);\r
1211 if (ret) return ret;\r
1212 }\r
1213 \r
1214 }\r
1215 \r
1216 plug_closing(p->plug, "Proxy error: Unexpected proxy error",\r
1217 PROXY_ERROR_UNEXPECTED, 0);\r
1218 return 1;\r
1219 }\r
1220 \r
1221 /* ----------------------------------------------------------------------\r
1222 * `Telnet' proxy type.\r
1223 *\r
1224 * (This is for ad-hoc proxies where you connect to the proxy's\r
1225 * telnet port and send a command such as `connect host port'. The\r
1226 * command is configurable, since this proxy type is typically not\r
1227 * standardised or at all well-defined.)\r
1228 */\r
1229 \r
1230 char *format_telnet_command(SockAddr addr, int port, Conf *conf)\r
1231 {\r
1232 char *fmt = conf_get_str(conf, CONF_proxy_telnet_command);\r
1233 char *ret = NULL;\r
1234 int retlen = 0, retsize = 0;\r
1235 int so = 0, eo = 0;\r
1236 #define ENSURE(n) do { \\r
1237 if (retsize < retlen + n) { \\r
1238 retsize = retlen + n + 512; \\r
1239 ret = sresize(ret, retsize, char); \\r
1240 } \\r
1241 } while (0)\r
1242 \r
1243 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, \r
1244 * %%, %host, %port, %user, and %pass\r
1245 */\r
1246 \r
1247 while (fmt[eo] != 0) {\r
1248 \r
1249 /* scan forward until we hit end-of-line,\r
1250 * or an escape character (\ or %) */\r
1251 while (fmt[eo] != 0 && fmt[eo] != '%' && fmt[eo] != '\\')\r
1252 eo++;\r
1253 \r
1254 /* if we hit eol, break out of our escaping loop */\r
1255 if (fmt[eo] == 0) break;\r
1256 \r
1257 /* if there was any unescaped text before the escape\r
1258 * character, send that now */\r
1259 if (eo != so) {\r
1260 ENSURE(eo - so);\r
1261 memcpy(ret + retlen, fmt + so, eo - so);\r
1262 retlen += eo - so;\r
1263 }\r
1264 \r
1265 so = eo++;\r
1266 \r
1267 /* if the escape character was the last character of\r
1268 * the line, we'll just stop and send it. */\r
1269 if (fmt[eo] == 0) break;\r
1270 \r
1271 if (fmt[so] == '\\') {\r
1272 \r
1273 /* we recognize \\, \%, \r, \n, \t, \x??.\r
1274 * anything else, we just send unescaped (including the \).\r
1275 */\r
1276 \r
1277 switch (fmt[eo]) {\r
1278 \r
1279 case '\\':\r
1280 ENSURE(1);\r
1281 ret[retlen++] = '\\';\r
1282 eo++;\r
1283 break;\r
1284 \r
1285 case '%':\r
1286 ENSURE(1);\r
1287 ret[retlen++] = '%';\r
1288 eo++;\r
1289 break;\r
1290 \r
1291 case 'r':\r
1292 ENSURE(1);\r
1293 ret[retlen++] = '\r';\r
1294 eo++;\r
1295 break;\r
1296 \r
1297 case 'n':\r
1298 ENSURE(1);\r
1299 ret[retlen++] = '\n';\r
1300 eo++;\r
1301 break;\r
1302 \r
1303 case 't':\r
1304 ENSURE(1);\r
1305 ret[retlen++] = '\t';\r
1306 eo++;\r
1307 break;\r
1308 \r
1309 case 'x':\r
1310 case 'X':\r
1311 {\r
1312 /* escaped hexadecimal value (ie. \xff) */\r
1313 unsigned char v = 0;\r
1314 int i = 0;\r
1315 \r
1316 for (;;) {\r
1317 eo++;\r
1318 if (fmt[eo] >= '0' && fmt[eo] <= '9')\r
1319 v += fmt[eo] - '0';\r
1320 else if (fmt[eo] >= 'a' && fmt[eo] <= 'f')\r
1321 v += fmt[eo] - 'a' + 10;\r
1322 else if (fmt[eo] >= 'A' && fmt[eo] <= 'F')\r
1323 v += fmt[eo] - 'A' + 10;\r
1324 else {\r
1325 /* non hex character, so we abort and just\r
1326 * send the whole thing unescaped (including \x)\r
1327 */\r
1328 ENSURE(1);\r
1329 ret[retlen++] = '\\';\r
1330 eo = so + 1;\r
1331 break;\r
1332 }\r
1333 \r
1334 /* we only extract two hex characters */\r
1335 if (i == 1) {\r
1336 ENSURE(1);\r
1337 ret[retlen++] = v;\r
1338 eo++;\r
1339 break;\r
1340 }\r
1341 \r
1342 i++;\r
1343 v <<= 4;\r
1344 }\r
1345 }\r
1346 break;\r
1347 \r
1348 default:\r
1349 ENSURE(2);\r
1350 memcpy(ret+retlen, fmt + so, 2);\r
1351 retlen += 2;\r
1352 eo++;\r
1353 break;\r
1354 }\r
1355 } else {\r
1356 \r
1357 /* % escape. we recognize %%, %host, %port, %user, %pass.\r
1358 * %proxyhost, %proxyport. Anything else we just send\r
1359 * unescaped (including the %).\r
1360 */\r
1361 \r
1362 if (fmt[eo] == '%') {\r
1363 ENSURE(1);\r
1364 ret[retlen++] = '%';\r
1365 eo++;\r
1366 }\r
1367 else if (strnicmp(fmt + eo, "host", 4) == 0) {\r
1368 char dest[512];\r
1369 int destlen;\r
1370 sk_getaddr(addr, dest, lenof(dest));\r
1371 destlen = strlen(dest);\r
1372 ENSURE(destlen);\r
1373 memcpy(ret+retlen, dest, destlen);\r
1374 retlen += destlen;\r
1375 eo += 4;\r
1376 }\r
1377 else if (strnicmp(fmt + eo, "port", 4) == 0) {\r
1378 char portstr[8], portlen;\r
1379 portlen = sprintf(portstr, "%i", port);\r
1380 ENSURE(portlen);\r
1381 memcpy(ret + retlen, portstr, portlen);\r
1382 retlen += portlen;\r
1383 eo += 4;\r
1384 }\r
1385 else if (strnicmp(fmt + eo, "user", 4) == 0) {\r
1386 char *username = conf_get_str(conf, CONF_proxy_username);\r
1387 int userlen = strlen(username);\r
1388 ENSURE(userlen);\r
1389 memcpy(ret+retlen, username, userlen);\r
1390 retlen += userlen;\r
1391 eo += 4;\r
1392 }\r
1393 else if (strnicmp(fmt + eo, "pass", 4) == 0) {\r
1394 char *password = conf_get_str(conf, CONF_proxy_password);\r
1395 int passlen = strlen(password);\r
1396 ENSURE(passlen);\r
1397 memcpy(ret+retlen, password, passlen);\r
1398 retlen += passlen;\r
1399 eo += 4;\r
1400 }\r
1401 else if (strnicmp(fmt + eo, "proxyhost", 9) == 0) {\r
1402 char *host = conf_get_str(conf, CONF_proxy_host);\r
1403 int phlen = strlen(host);\r
1404 ENSURE(phlen);\r
1405 memcpy(ret+retlen, host, phlen);\r
1406 retlen += phlen;\r
1407 eo += 9;\r
1408 }\r
1409 else if (strnicmp(fmt + eo, "proxyport", 9) == 0) {\r
1410 int port = conf_get_int(conf, CONF_proxy_port);\r
1411 char pport[50];\r
1412 int pplen;\r
1413 sprintf(pport, "%d", port);\r
1414 pplen = strlen(pport);\r
1415 ENSURE(pplen);\r
1416 memcpy(ret+retlen, pport, pplen);\r
1417 retlen += pplen;\r
1418 eo += 9;\r
1419 }\r
1420 else {\r
1421 /* we don't escape this, so send the % now, and\r
1422 * don't advance eo, so that we'll consider the\r
1423 * text immediately following the % as unescaped.\r
1424 */\r
1425 ENSURE(1);\r
1426 ret[retlen++] = '%';\r
1427 }\r
1428 }\r
1429 \r
1430 /* resume scanning for additional escapes after this one. */\r
1431 so = eo;\r
1432 }\r
1433 \r
1434 /* if there is any unescaped text at the end of the line, send it */\r
1435 if (eo != so) {\r
1436 ENSURE(eo - so);\r
1437 memcpy(ret + retlen, fmt + so, eo - so);\r
1438 retlen += eo - so;\r
1439 }\r
1440 \r
1441 ENSURE(1);\r
1442 ret[retlen] = '\0';\r
1443 return ret;\r
1444 \r
1445 #undef ENSURE\r
1446 }\r
1447 \r
1448 int proxy_telnet_negotiate (Proxy_Socket p, int change)\r
1449 {\r
1450 if (p->state == PROXY_CHANGE_NEW) {\r
1451 char *formatted_cmd;\r
1452 \r
1453 formatted_cmd = format_telnet_command(p->remote_addr, p->remote_port,\r
1454 p->conf);\r
1455 \r
1456 sk_write(p->sub_socket, formatted_cmd, strlen(formatted_cmd));\r
1457 sfree(formatted_cmd);\r
1458 \r
1459 p->state = 1;\r
1460 return 0;\r
1461 }\r
1462 \r
1463 if (change == PROXY_CHANGE_CLOSING) {\r
1464 /* if our proxy negotiation process involves closing and opening\r
1465 * new sockets, then we would want to intercept this closing\r
1466 * callback when we were expecting it. if we aren't anticipating\r
1467 * a socket close, then some error must have occurred. we'll\r
1468 * just pass those errors up to the backend.\r
1469 */\r
1470 return plug_closing(p->plug, p->closing_error_msg,\r
1471 p->closing_error_code,\r
1472 p->closing_calling_back);\r
1473 }\r
1474 \r
1475 if (change == PROXY_CHANGE_SENT) {\r
1476 /* some (or all) of what we wrote to the proxy was sent.\r
1477 * we don't do anything new, however, until we receive the\r
1478 * proxy's response. we might want to set a timer so we can\r
1479 * timeout the proxy negotiation after a while...\r
1480 */\r
1481 return 0;\r
1482 }\r
1483 \r
1484 if (change == PROXY_CHANGE_ACCEPTING) {\r
1485 /* we should _never_ see this, as we are using our socket to\r
1486 * connect to a proxy, not accepting inbound connections.\r
1487 * what should we do? close the socket with an appropriate\r
1488 * error message?\r
1489 */\r
1490 return plug_accepting(p->plug,\r
1491 p->accepting_constructor, p->accepting_ctx);\r
1492 }\r
1493 \r
1494 if (change == PROXY_CHANGE_RECEIVE) {\r
1495 /* we have received data from the underlying socket, which\r
1496 * we'll need to parse, process, and respond to appropriately.\r
1497 */\r
1498 \r
1499 /* we're done */\r
1500 proxy_activate(p);\r
1501 /* proxy activate will have dealt with\r
1502 * whatever is left of the buffer */\r
1503 return 1;\r
1504 }\r
1505 \r
1506 plug_closing(p->plug, "Proxy error: Unexpected proxy error",\r
1507 PROXY_ERROR_UNEXPECTED, 0);\r
1508 return 1;\r
1509 }\r