2 * Network proxy abstraction in PuTTY
4 * A proxy layer, if necessary, wedges itself between the network
5 * code and the higher level backend.
10 #define DEFINE_PLUG_METHOD_MACROS
16 * Call this when proxy negotiation is complete, so that this
17 * socket can begin working normally.
19 void proxy_activate (Proxy_Socket p)
24 p->state = PROXY_STATE_ACTIVE;
26 /* let's try to keep extra receive events from coming through */
27 sk_set_frozen(p->sub_socket, 1);
29 /* send buffered OOB writes */
30 while (bufchain_size(&p->pending_oob_output_data) > 0) {
31 bufchain_prefix(&p->pending_oob_output_data, &data, &len);
32 sk_write_oob(p->sub_socket, data, len);
33 bufchain_consume(&p->pending_oob_output_data, len);
35 bufchain_clear(&p->pending_oob_output_data);
37 /* send buffered normal writes */
38 while (bufchain_size(&p->pending_output_data) > 0) {
39 bufchain_prefix(&p->pending_output_data, &data, &len);
40 sk_write(p->sub_socket, data, len);
41 bufchain_consume(&p->pending_output_data, len);
43 bufchain_clear(&p->pending_output_data);
45 /* if we were asked to flush the output during
46 * the proxy negotiation process, do so now.
48 if (p->pending_flush) sk_flush(p->sub_socket);
50 /* forward buffered recv data to the backend */
51 while (bufchain_size(&p->pending_input_data) > 0) {
52 bufchain_prefix(&p->pending_input_data, &data, &len);
53 plug_receive(p->plug, 0, data, len);
54 bufchain_consume(&p->pending_input_data, len);
56 bufchain_clear(&p->pending_input_data);
58 /* now set the underlying socket to whatever freeze state they wanted */
59 sk_set_frozen(p->sub_socket, p->freeze);
62 /* basic proxy socket functions */
64 static Plug sk_proxy_plug (Socket s, Plug p)
66 Proxy_Socket ps = (Proxy_Socket) s;
73 static void sk_proxy_close (Socket s)
75 Proxy_Socket ps = (Proxy_Socket) s;
77 sk_close(ps->sub_socket);
81 static int sk_proxy_write (Socket s, char *data, int len)
83 Proxy_Socket ps = (Proxy_Socket) s;
85 if (ps->state != PROXY_STATE_ACTIVE) {
86 bufchain_add(&ps->pending_output_data, data, len);
87 return bufchain_size(&ps->pending_output_data);
89 return sk_write(ps->sub_socket, data, len);
92 static int sk_proxy_write_oob (Socket s, char *data, int len)
94 Proxy_Socket ps = (Proxy_Socket) s;
96 if (ps->state != PROXY_STATE_ACTIVE) {
97 bufchain_clear(&ps->pending_output_data);
98 bufchain_clear(&ps->pending_oob_output_data);
99 bufchain_add(&ps->pending_oob_output_data, data, len);
102 return sk_write_oob(ps->sub_socket, data, len);
105 static void sk_proxy_flush (Socket s)
107 Proxy_Socket ps = (Proxy_Socket) s;
109 if (ps->state != PROXY_STATE_ACTIVE) {
110 ps->pending_flush = 1;
113 sk_flush(ps->sub_socket);
116 static void sk_proxy_set_private_ptr (Socket s, void *ptr)
118 Proxy_Socket ps = (Proxy_Socket) s;
119 sk_set_private_ptr(ps->sub_socket, ptr);
122 static void * sk_proxy_get_private_ptr (Socket s)
124 Proxy_Socket ps = (Proxy_Socket) s;
125 return sk_get_private_ptr(ps->sub_socket);
128 static void sk_proxy_set_frozen (Socket s, int is_frozen)
130 Proxy_Socket ps = (Proxy_Socket) s;
132 if (ps->state != PROXY_STATE_ACTIVE) {
133 ps->freeze = is_frozen;
136 sk_set_frozen(ps->sub_socket, is_frozen);
139 static char * sk_proxy_socket_error (Socket s)
141 Proxy_Socket ps = (Proxy_Socket) s;
142 if (ps->error != NULL || ps->sub_socket == NULL) {
145 return sk_socket_error(ps->sub_socket);
148 /* basic proxy plug functions */
150 static int plug_proxy_closing (Plug p, char *error_msg,
151 int error_code, int calling_back)
153 Proxy_Plug pp = (Proxy_Plug) p;
154 Proxy_Socket ps = pp->proxy_socket;
156 if (ps->state != PROXY_STATE_ACTIVE) {
157 ps->closing_error_msg = error_msg;
158 ps->closing_error_code = error_code;
159 ps->closing_calling_back = calling_back;
160 return ps->negotiate(ps, PROXY_CHANGE_CLOSING);
162 return plug_closing(ps->plug, error_msg,
163 error_code, calling_back);
166 static int plug_proxy_receive (Plug p, int urgent, char *data, int len)
168 Proxy_Plug pp = (Proxy_Plug) p;
169 Proxy_Socket ps = pp->proxy_socket;
171 if (ps->state != PROXY_STATE_ACTIVE) {
172 /* we will lose the urgentness of this data, but since most,
173 * if not all, of this data will be consumed by the negotiation
174 * process, hopefully it won't affect the protocol above us
176 bufchain_add(&ps->pending_input_data, data, len);
177 ps->receive_urgent = urgent;
178 ps->receive_data = data;
179 ps->receive_len = len;
180 return ps->negotiate(ps, PROXY_CHANGE_RECEIVE);
182 return plug_receive(ps->plug, urgent, data, len);
185 static void plug_proxy_sent (Plug p, int bufsize)
187 Proxy_Plug pp = (Proxy_Plug) p;
188 Proxy_Socket ps = pp->proxy_socket;
190 if (ps->state != PROXY_STATE_ACTIVE) {
191 ps->sent_bufsize = bufsize;
192 ps->negotiate(ps, PROXY_CHANGE_SENT);
195 plug_sent(ps->plug, bufsize);
198 static int plug_proxy_accepting (Plug p, void *sock)
200 Proxy_Plug pp = (Proxy_Plug) p;
201 Proxy_Socket ps = pp->proxy_socket;
203 if (ps->state != PROXY_STATE_ACTIVE) {
204 ps->accepting_sock = sock;
205 return ps->negotiate(ps, PROXY_CHANGE_ACCEPTING);
207 return plug_accepting(ps->plug, sock);
210 static int proxy_for_destination (SockAddr addr, char * hostname, int port)
214 int hostip_len, hostname_len;
217 /* we want a string representation of the IP address for comparisons */
218 sk_getaddr(addr, hostip, 64);
220 hostip_len = strlen(hostip);
221 hostname_len = strlen(hostname);
223 exclude_list = cfg.proxy_exclude_list;
225 /* now parse the exclude list, and see if either our IP
226 * or hostname matches anything in it.
229 while (exclude_list[s]) {
230 while (exclude_list[s] &&
231 (isspace(exclude_list[s]) ||
232 exclude_list[s] == ',')) s++;
234 if (!exclude_list[s]) break;
238 while (exclude_list[e] &&
239 (isalnum(exclude_list[e]) ||
240 exclude_list[e] == '-' ||
241 exclude_list[e] == '.' ||
242 exclude_list[e] == '*')) e++;
244 if (exclude_list[s] == '*') {
245 /* wildcard at beginning of entry */
247 if (strnicmp(hostip + hostip_len - (e - s - 1),
248 exclude_list + s + 1, e - s - 1) == 0 ||
249 strnicmp(hostname + hostname_len - (e - s - 1),
250 exclude_list + s + 1, e - s - 1) == 0)
251 return 0; /* IP/hostname range excluded. do not use proxy. */
253 } else if (exclude_list[e-1] == '*') {
254 /* wildcard at end of entry */
256 if (strnicmp(hostip, exclude_list + s, e - s - 1) == 0 ||
257 strnicmp(hostname, exclude_list + s, e - s - 1) == 0)
258 return 0; /* IP/hostname range excluded. do not use proxy. */
261 /* no wildcard at either end, so let's try an absolute
262 * match (ie. a specific IP)
265 if (stricmp(hostip, exclude_list + s) == 0)
266 return 0; /* IP/hostname excluded. do not use proxy. */
267 if (stricmp(hostname, exclude_list + s) == 0)
268 return 0; /* IP/hostname excluded. do not use proxy. */
274 /* no matches in the exclude list, so use the proxy */
278 Socket new_connection(SockAddr addr, char *hostname,
279 int port, int privport,
280 int oobinline, int nodelay, Plug plug)
282 static struct socket_function_table socket_fn_table = {
288 sk_proxy_set_private_ptr,
289 sk_proxy_get_private_ptr,
291 sk_proxy_socket_error
294 static struct plug_function_table plug_fn_table = {
301 if (cfg.proxy_type != PROXY_NONE &&
302 proxy_for_destination(addr, hostname, port))
307 char * proxy_canonical_name;
309 ret = smalloc(sizeof(struct Socket_proxy_tag));
310 ret->fn = &socket_fn_table;
312 ret->remote_addr = addr;
313 ret->remote_port = port;
315 bufchain_init(&ret->pending_input_data);
316 bufchain_init(&ret->pending_output_data);
317 bufchain_init(&ret->pending_oob_output_data);
319 ret->sub_socket = NULL;
320 ret->state = PROXY_STATE_NEW;
322 if (cfg.proxy_type == PROXY_HTTP) {
323 ret->negotiate = proxy_http_negotiate;
324 } else if (cfg.proxy_type == PROXY_SOCKS) {
325 if (cfg.proxy_socks_version == 4)
326 ret->negotiate = proxy_socks4_negotiate;
328 ret->negotiate = proxy_socks5_negotiate;
329 } else if (cfg.proxy_type == PROXY_TELNET) {
330 ret->negotiate = proxy_telnet_negotiate;
332 ret->error = "Network error: Unknown proxy method";
336 /* create the proxy plug to map calls from the actual
337 * socket into our proxy socket layer */
338 pplug = smalloc(sizeof(struct Plug_proxy_tag));
339 pplug->fn = &plug_fn_table;
340 pplug->proxy_socket = ret;
343 proxy_addr = sk_namelookup(cfg.proxy_host,
344 &proxy_canonical_name);
345 sfree(proxy_canonical_name);
347 /* create the actual socket we will be using,
348 * connected to our proxy server and port.
350 ret->sub_socket = sk_new(proxy_addr, cfg.proxy_port,
352 nodelay, (Plug) pplug);
353 if (sk_socket_error(ret->sub_socket) != NULL)
356 sk_addr_free(proxy_addr);
358 /* start the proxy negotiation process... */
359 sk_set_frozen(ret->sub_socket, 0);
360 ret->negotiate(ret, PROXY_CHANGE_NEW);
365 /* no proxy, so just return the direct socket */
366 return sk_new(addr, port, privport, oobinline, nodelay, plug);
369 Socket new_listener(int port, Plug plug, int local_host_only)
371 /* TODO: SOCKS (and potentially others) support inbound
372 * TODO: connections via the proxy. support them.
375 return sk_newlistener(port, plug, local_host_only);
378 /* ----------------------------------------------------------------------
379 * HTTP CONNECT proxy type.
382 static int get_line_end (char * data, int len)
388 if (data[off] == '\n') {
389 /* we have a newline */
392 /* is that the only thing on this line? */
393 if (off <= 2) return off;
395 /* if not, then there is the possibility that this header
396 * continues onto the next line, if it starts with a space
401 data[off+1] != ' ' &&
402 data[off+1] != '\t') return off;
404 /* the line does continue, so we have to keep going
405 * until we see an the header's "real" end of line.
416 int proxy_http_negotiate (Proxy_Socket p, int change)
418 if (p->state == PROXY_STATE_NEW) {
419 /* we are just beginning the proxy negotiate process,
420 * so we'll send off the initial bits of the request.
421 * for this proxy method, it's just a simple HTTP
424 char buf[256], dest[64];
426 sk_getaddr(p->remote_addr, dest, 64);
428 sprintf(buf, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
429 dest, p->remote_port, dest, p->remote_port);
430 sk_write(p->sub_socket, buf, strlen(buf));
432 if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
433 char buf[sizeof(cfg.proxy_username)+sizeof(cfg.proxy_password)];
434 char buf2[sizeof(buf)*4/3 + 100];
436 sprintf(buf, "%s:%s", cfg.proxy_username, cfg.proxy_password);
438 sprintf(buf2, "Proxy-Authorization: basic ");
439 for (i = 0, j = strlen(buf2); i < len; i += 3, j += 4)
440 base64_encode_atom(buf+i, (len-i > 3 ? 3 : len-i), buf2+j);
441 strcpy(buf2+j, "\r\n");
442 sk_write(p->sub_socket, buf2, strlen(buf2));
445 sprintf(buf, "\r\n");
446 sk_write(p->sub_socket, buf, strlen(buf));
452 if (change == PROXY_CHANGE_CLOSING) {
453 /* if our proxy negotiation process involves closing and opening
454 * new sockets, then we would want to intercept this closing
455 * callback when we were expecting it. if we aren't anticipating
456 * a socket close, then some error must have occurred. we'll
457 * just pass those errors up to the backend.
459 return plug_closing(p->plug, p->closing_error_msg,
460 p->closing_error_code,
461 p->closing_calling_back);
464 if (change == PROXY_CHANGE_SENT) {
465 /* some (or all) of what we wrote to the proxy was sent.
466 * we don't do anything new, however, until we receive the
467 * proxy's response. we might want to set a timer so we can
468 * timeout the proxy negotiation after a while...
473 if (change == PROXY_CHANGE_ACCEPTING) {
474 /* we should _never_ see this, as we are using our socket to
475 * connect to a proxy, not accepting inbound connections.
476 * what should we do? close the socket with an appropriate
479 return plug_accepting(p->plug, p->accepting_sock);
482 if (change == PROXY_CHANGE_RECEIVE) {
483 /* we have received data from the underlying socket, which
484 * we'll need to parse, process, and respond to appropriately.
493 int min_ver, maj_ver, status;
495 /* get the status line */
496 bufchain_prefix(&p->pending_input_data, &data, &len);
497 eol = get_line_end(data, len);
498 if (eol < 0) return 1;
500 sscanf((char *)data, "HTTP/%i.%i %i", &maj_ver, &min_ver, &status);
502 /* remove the status line from the input buffer. */
503 bufchain_consume(&p->pending_input_data, eol);
505 /* TODO: we need to support Proxy-Auth headers */
507 if (status < 200 || status > 299) {
509 /* TODO: return a more specific error message,
510 * TODO: based on the status code.
512 plug_closing(p->plug, "Network error: Error while communicating with proxy",
513 PROXY_ERROR_GENERAL, 0);
522 /* get headers. we're done when we get a
523 * header of length 2, (ie. just "\r\n")
526 bufchain_prefix(&p->pending_input_data, &data, &len);
527 eol = get_line_end(data, len);
530 /* TODO: Proxy-Auth stuff. in some cases, we will
531 * TODO: need to extract information from headers.
533 bufchain_consume(&p->pending_input_data, eol);
534 bufchain_prefix(&p->pending_input_data, &data, &len);
535 eol = get_line_end(data, len);
540 bufchain_consume(&p->pending_input_data, 2);
542 /* proxy activate will have dealt with
543 * whatever is left of the buffer */
551 plug_closing(p->plug, "Network error: Unexpected proxy error",
552 PROXY_ERROR_UNEXPECTED, 0);
556 /* ----------------------------------------------------------------------
560 /* SOCKS version 4 */
561 int proxy_socks4_negotiate (Proxy_Socket p, int change)
563 if (p->state == PROXY_CHANGE_NEW) {
566 * version number (1 byte) = 4
567 * command code (1 byte)
570 * dest. port (2 bytes) [network order]
571 * dest. address (4 bytes)
572 * user ID (variable length, null terminated string)
578 if (sk_addrtype(p->remote_addr) != AF_INET) {
579 plug_closing(p->plug, "Network error: SOCKS version 4 does not support IPv6",
580 PROXY_ERROR_GENERAL, 0);
584 length = strlen(cfg.proxy_username) + 9;
585 command = (char*) malloc(length);
586 strcpy(command + 8, cfg.proxy_username);
588 command[0] = 4; /* version 4 */
589 command[1] = 1; /* CONNECT command */
592 command[2] = (char) (p->remote_port >> 8) & 0xff;
593 command[3] = (char) p->remote_port & 0xff;
596 sk_addrcopy(p->remote_addr, command + 4);
598 sk_write(p->sub_socket, command, length);
605 if (change == PROXY_CHANGE_CLOSING) {
606 /* if our proxy negotiation process involves closing and opening
607 * new sockets, then we would want to intercept this closing
608 * callback when we were expecting it. if we aren't anticipating
609 * a socket close, then some error must have occurred. we'll
610 * just pass those errors up to the backend.
612 return plug_closing(p->plug, p->closing_error_msg,
613 p->closing_error_code,
614 p->closing_calling_back);
617 if (change == PROXY_CHANGE_SENT) {
618 /* some (or all) of what we wrote to the proxy was sent.
619 * we don't do anything new, however, until we receive the
620 * proxy's response. we might want to set a timer so we can
621 * timeout the proxy negotiation after a while...
626 if (change == PROXY_CHANGE_ACCEPTING) {
627 /* we should _never_ see this, as we are using our socket to
628 * connect to a proxy, not accepting inbound connections.
629 * what should we do? close the socket with an appropriate
632 return plug_accepting(p->plug, p->accepting_sock);
635 if (change == PROXY_CHANGE_RECEIVE) {
636 /* we have received data from the underlying socket, which
637 * we'll need to parse, process, and respond to appropriately.
642 * version number (1 byte) = 4
643 * reply code (1 byte)
644 * 90 = request granted
645 * 91 = request rejected or failed
646 * 92 = request rejected due to lack of IDENTD on client
647 * 93 = request rejected due to difference in user ID
648 * (what we sent vs. what IDENTD said)
649 * dest. port (2 bytes)
650 * dest. address (4 bytes)
656 /* get the response */
657 bufchain_prefix(&p->pending_input_data, &data, &len);
660 plug_closing(p->plug, "Network error: SOCKS proxy responded with "
661 "unexpected reply code version",
662 PROXY_ERROR_GENERAL, 0);
670 plug_closing(p->plug, "Network error: SOCKS server wanted IDENTD on client",
671 PROXY_ERROR_GENERAL, 0);
674 plug_closing(p->plug, "Network error: Username and IDENTD on client don't agree",
675 PROXY_ERROR_GENERAL, 0);
679 plug_closing(p->plug, "Network error: Error while communicating with proxy",
680 PROXY_ERROR_GENERAL, 0);
686 bufchain_consume(&p->pending_input_data, 2);
690 /* proxy activate will have dealt with
691 * whatever is left of the buffer */
696 plug_closing(p->plug, "Network error: Unexpected proxy error",
697 PROXY_ERROR_UNEXPECTED, 0);
701 /* SOCKS version 5 */
702 int proxy_socks5_negotiate (Proxy_Socket p, int change)
704 if (p->state == PROXY_CHANGE_NEW) {
707 * version number (1 byte) = 5
708 * number of available authentication methods (1 byte)
709 * available authentication methods (1 byte * previous value)
710 * authentication methods:
711 * 0x00 = no authentication
713 * 0x02 = username/password
720 command[0] = 5; /* version 5 */
721 if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
722 command[1] = 2; /* two methods supported: */
723 command[2] = 0x00; /* no authentication */
724 command[3] = 0x02; /* username/password */
727 command[1] = 1; /* one methods supported: */
728 command[2] = 0x00; /* no authentication */
732 sk_write(p->sub_socket, command, len);
738 if (change == PROXY_CHANGE_CLOSING) {
739 /* if our proxy negotiation process involves closing and opening
740 * new sockets, then we would want to intercept this closing
741 * callback when we were expecting it. if we aren't anticipating
742 * a socket close, then some error must have occurred. we'll
743 * just pass those errors up to the backend.
745 return plug_closing(p->plug, p->closing_error_msg,
746 p->closing_error_code,
747 p->closing_calling_back);
750 if (change == PROXY_CHANGE_SENT) {
751 /* some (or all) of what we wrote to the proxy was sent.
752 * we don't do anything new, however, until we receive the
753 * proxy's response. we might want to set a timer so we can
754 * timeout the proxy negotiation after a while...
759 if (change == PROXY_CHANGE_ACCEPTING) {
760 /* we should _never_ see this, as we are using our socket to
761 * connect to a proxy, not accepting inbound connections.
762 * what should we do? close the socket with an appropriate
765 return plug_accepting(p->plug, p->accepting_sock);
768 if (change == PROXY_CHANGE_RECEIVE) {
769 /* we have received data from the underlying socket, which
770 * we'll need to parse, process, and respond to appropriately.
779 * version number (1 byte) = 5
780 * authentication method (1 byte)
781 * authentication methods:
782 * 0x00 = no authentication
784 * 0x02 = username/password
786 * 0xff = no acceptable methods
789 /* get the response */
790 bufchain_prefix(&p->pending_input_data, &data, &len);
793 plug_closing(p->plug, "Network error: Error while communicating with proxy",
794 PROXY_ERROR_GENERAL, 0);
798 if (data[1] == 0x00) p->state = 2; /* no authentication needed */
799 else if (data[1] == 0x01) p->state = 4; /* GSSAPI authentication */
800 else if (data[1] == 0x02) p->state = 5; /* username/password authentication */
801 else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */
803 plug_closing(p->plug, "Network error: We don't support any of the SOCKS "
804 "server's authentication methods",
805 PROXY_ERROR_GENERAL, 0);
808 bufchain_consume(&p->pending_input_data, 2);
813 /* password authentication reply format:
814 * version number (1 bytes) = 1
815 * reply code (1 byte)
820 /* get the response */
821 bufchain_prefix(&p->pending_input_data, &data, &len);
824 plug_closing(p->plug, "Network error: Error while communicating with proxy",
825 PROXY_ERROR_GENERAL, 0);
831 plug_closing(p->plug, "Network error: Proxy refused authentication",
832 PROXY_ERROR_GENERAL, 0);
836 bufchain_consume(&p->pending_input_data, 2);
837 p->state = 2; /* now proceed as authenticated */
843 * version number (1 byte) = 5
844 * command code (1 byte)
848 * reserved (1 byte) = 0x00
849 * address type (1 byte)
851 * 3 = domainname (first byte has length, no terminating null)
853 * dest. address (variable)
854 * dest. port (2 bytes) [network order]
860 if (sk_addrtype(p->remote_addr) == AF_INET) {
862 command[3] = 1; /* IPv4 */
865 command[3] = 4; /* IPv6 */
868 command[0] = 5; /* version 5 */
869 command[1] = 1; /* CONNECT command */
873 sk_addrcopy(p->remote_addr, command+4);
876 command[len-2] = (char) (p->remote_port >> 8) & 0xff;
877 command[len-1] = (char) p->remote_port & 0xff;
879 sk_write(p->sub_socket, command, len);
888 * version number (1 bytes) = 5
889 * reply code (1 byte)
891 * 1 = general SOCKS server failure
892 * 2 = connection not allowed by ruleset
893 * 3 = network unreachable
894 * 4 = host unreachable
895 * 5 = connection refused
897 * 7 = command not supported
898 * 8 = address type not supported
899 * reserved (1 byte) = x00
900 * address type (1 byte)
902 * 3 = domainname (first byte has length, no terminating null)
904 * server bound address (variable)
905 * server bound port (2 bytes) [network order]
908 /* get the response */
909 bufchain_prefix(&p->pending_input_data, &data, &len);
912 plug_closing(p->plug, "Network error: Error while communicating with proxy",
913 PROXY_ERROR_GENERAL, 0);
929 plug_closing(p->plug, "Network error: Error while communicating with proxy",
930 PROXY_ERROR_GENERAL, 0);
939 /* proxy activate will have dealt with
940 * whatever is left of the buffer */
945 /* TODO: Handle GSSAPI authentication */
946 plug_closing(p->plug, "Network error: We don't support GSSAPI authentication",
947 PROXY_ERROR_GENERAL, 0);
952 if (cfg.proxy_username[0] || cfg.proxy_password[0]) {
955 ulen = strlen(cfg.proxy_username);
956 if (ulen > 255) ulen = 255; if (ulen < 1) ulen = 1;
957 plen = strlen(cfg.proxy_password);
958 if (plen > 255) plen = 255; if (plen < 1) plen = 1;
959 userpwbuf[0] = 1; /* version number of subnegotiation */
961 memcpy(userpwbuf+2, cfg.proxy_username, ulen);
962 userpwbuf[ulen+2] = plen;
963 memcpy(userpwbuf+ulen+3, cfg.proxy_password, plen);
964 sk_write(p->sub_socket, userpwbuf, ulen + plen + 3);
967 plug_closing(p->plug, "Network error: Server chose "
968 "username/password authentication but we "
970 PROXY_ERROR_GENERAL, 0);
975 /* TODO: Handle CHAP authentication */
976 plug_closing(p->plug, "Network error: We don't support CHAP authentication",
977 PROXY_ERROR_GENERAL, 0);
983 plug_closing(p->plug, "Network error: Unexpected proxy error",
984 PROXY_ERROR_UNEXPECTED, 0);
988 /* ----------------------------------------------------------------------
989 * `Telnet' proxy type.
991 * (This is for ad-hoc proxies where you connect to the proxy's
992 * telnet port and send a command such as `connect host port'. The
993 * command is configurable, since this proxy type is typically not
994 * standardised or at all well-defined.)
997 int proxy_telnet_negotiate (Proxy_Socket p, int change)
999 if (p->state == PROXY_CHANGE_NEW) {
1003 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
1004 * %%, %host, and %port
1007 while (cfg.proxy_telnet_command[eo] != 0) {
1009 /* scan forward until we hit end-of-line,
1010 * or an escape character (\ or %) */
1011 while (cfg.proxy_telnet_command[eo] != 0 &&
1012 cfg.proxy_telnet_command[eo] != '%' &&
1013 cfg.proxy_telnet_command[eo] != '\\') eo++;
1015 /* if we hit eol, break out of our escaping loop */
1016 if (cfg.proxy_telnet_command[eo] == 0) break;
1018 /* if there was any unescaped text before the escape
1019 * character, send that now */
1021 sk_write(p->sub_socket,
1022 cfg.proxy_telnet_command + so, eo - so);
1027 /* if the escape character was the last character of
1028 * the line, we'll just stop and send it. */
1029 if (cfg.proxy_telnet_command[eo] == 0) break;
1031 if (cfg.proxy_telnet_command[so] == '\\') {
1033 /* we recognize \\, \%, \r, \n, \t, \x??.
1034 * anything else, we just send unescaped (including the \).
1037 switch (cfg.proxy_telnet_command[eo]) {
1040 sk_write(p->sub_socket, "\\", 1);
1045 sk_write(p->sub_socket, "%%", 1);
1050 sk_write(p->sub_socket, "\r", 1);
1055 sk_write(p->sub_socket, "\n", 1);
1060 sk_write(p->sub_socket, "\t", 1);
1067 /* escaped hexadecimal value (ie. \xff) */
1068 unsigned char v = 0;
1073 if (cfg.proxy_telnet_command[eo] >= '0' &&
1074 cfg.proxy_telnet_command[eo] <= '9')
1075 v += cfg.proxy_telnet_command[eo] - '0';
1076 else if (cfg.proxy_telnet_command[eo] >= 'a' &&
1077 cfg.proxy_telnet_command[eo] <= 'f')
1078 v += cfg.proxy_telnet_command[eo] - 'a' + 10;
1079 else if (cfg.proxy_telnet_command[eo] >= 'A' &&
1080 cfg.proxy_telnet_command[eo] <= 'F')
1081 v += cfg.proxy_telnet_command[eo] - 'A' + 10;
1083 /* non hex character, so we abort and just
1084 * send the whole thing unescaped (including \x)
1086 sk_write(p->sub_socket, "\\", 1);
1091 /* we only extract two hex characters */
1093 sk_write(p->sub_socket, &v, 1);
1105 sk_write(p->sub_socket,
1106 cfg.proxy_telnet_command + so, 2);
1112 /* % escape. we recognize %%, %host, %port. anything else,
1113 * we just send unescaped (including the %). */
1115 if (cfg.proxy_telnet_command[eo] == '%') {
1116 sk_write(p->sub_socket, "%", 1);
1119 else if (strnicmp(cfg.proxy_telnet_command + eo,
1122 sk_getaddr(p->remote_addr, dest, 64);
1123 sk_write(p->sub_socket, dest, strlen(dest));
1126 else if (strnicmp(cfg.proxy_telnet_command + eo,
1129 sprintf(port, "%i", p->remote_port);
1130 sk_write(p->sub_socket, port, strlen(port));
1134 /* we don't escape this, so send the % now, and
1135 * don't advance eo, so that we'll consider the
1136 * text immediately following the % as unescaped.
1138 sk_write(p->sub_socket, "%", 1);
1142 /* resume scanning for additional escapes after this one. */
1146 /* if there is any unescaped text at the end of the line, send it */
1148 sk_write(p->sub_socket, cfg.proxy_telnet_command + so, eo - so);
1155 if (change == PROXY_CHANGE_CLOSING) {
1156 /* if our proxy negotiation process involves closing and opening
1157 * new sockets, then we would want to intercept this closing
1158 * callback when we were expecting it. if we aren't anticipating
1159 * a socket close, then some error must have occurred. we'll
1160 * just pass those errors up to the backend.
1162 return plug_closing(p->plug, p->closing_error_msg,
1163 p->closing_error_code,
1164 p->closing_calling_back);
1167 if (change == PROXY_CHANGE_SENT) {
1168 /* some (or all) of what we wrote to the proxy was sent.
1169 * we don't do anything new, however, until we receive the
1170 * proxy's response. we might want to set a timer so we can
1171 * timeout the proxy negotiation after a while...
1176 if (change == PROXY_CHANGE_ACCEPTING) {
1177 /* we should _never_ see this, as we are using our socket to
1178 * connect to a proxy, not accepting inbound connections.
1179 * what should we do? close the socket with an appropriate
1182 return plug_accepting(p->plug, p->accepting_sock);
1185 if (change == PROXY_CHANGE_RECEIVE) {
1186 /* we have received data from the underlying socket, which
1187 * we'll need to parse, process, and respond to appropriately.
1192 /* proxy activate will have dealt with
1193 * whatever is left of the buffer */
1197 plug_closing(p->plug, "Network error: Unexpected proxy error",
1198 PROXY_ERROR_UNEXPECTED, 0);