2 * Network proxy abstraction in PuTTY
4 * A proxy layer, if necessary, wedges itself between the network
5 * code and the higher level backend.
12 #define DEFINE_PLUG_METHOD_MACROS
18 * Call this when proxy negotiation is complete, so that this
19 * socket can begin working normally.
21 void proxy_activate (Proxy_Socket p
)
26 p
->state
= PROXY_STATE_ACTIVE
;
28 /* let's try to keep extra receive events from coming through */
29 sk_set_frozen(p
->sub_socket
, 1);
31 /* send buffered OOB writes */
32 while (bufchain_size(&p
->pending_oob_output_data
) > 0) {
33 bufchain_prefix(&p
->pending_oob_output_data
, &data
, &len
);
34 sk_write_oob(p
->sub_socket
, data
, len
);
35 bufchain_consume(&p
->pending_oob_output_data
, len
);
37 bufchain_clear(&p
->pending_oob_output_data
);
39 /* send buffered normal writes */
40 while (bufchain_size(&p
->pending_output_data
) > 0) {
41 bufchain_prefix(&p
->pending_output_data
, &data
, &len
);
42 sk_write(p
->sub_socket
, data
, len
);
43 bufchain_consume(&p
->pending_output_data
, len
);
45 bufchain_clear(&p
->pending_output_data
);
47 /* if we were asked to flush the output during
48 * the proxy negotiation process, do so now.
50 if (p
->pending_flush
) sk_flush(p
->sub_socket
);
52 /* forward buffered recv data to the backend */
53 while (bufchain_size(&p
->pending_input_data
) > 0) {
54 bufchain_prefix(&p
->pending_input_data
, &data
, &len
);
55 plug_receive(p
->plug
, 0, data
, len
);
56 bufchain_consume(&p
->pending_input_data
, len
);
58 bufchain_clear(&p
->pending_input_data
);
60 /* now set the underlying socket to whatever freeze state they wanted */
61 sk_set_frozen(p
->sub_socket
, p
->freeze
);
64 /* basic proxy socket functions */
66 static Plug
sk_proxy_plug (Socket s
, Plug p
)
68 Proxy_Socket ps
= (Proxy_Socket
) s
;
75 static void sk_proxy_close (Socket s
)
77 Proxy_Socket ps
= (Proxy_Socket
) s
;
79 sk_close(ps
->sub_socket
);
83 static int sk_proxy_write (Socket s
, char *data
, int len
)
85 Proxy_Socket ps
= (Proxy_Socket
) s
;
87 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
88 bufchain_add(&ps
->pending_output_data
, data
, len
);
89 return bufchain_size(&ps
->pending_output_data
);
91 return sk_write(ps
->sub_socket
, data
, len
);
94 static int sk_proxy_write_oob (Socket s
, char *data
, int len
)
96 Proxy_Socket ps
= (Proxy_Socket
) s
;
98 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
99 bufchain_clear(&ps
->pending_output_data
);
100 bufchain_clear(&ps
->pending_oob_output_data
);
101 bufchain_add(&ps
->pending_oob_output_data
, data
, len
);
104 return sk_write_oob(ps
->sub_socket
, data
, len
);
107 static void sk_proxy_flush (Socket s
)
109 Proxy_Socket ps
= (Proxy_Socket
) s
;
111 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
112 ps
->pending_flush
= 1;
115 sk_flush(ps
->sub_socket
);
118 static void sk_proxy_set_private_ptr (Socket s
, void *ptr
)
120 Proxy_Socket ps
= (Proxy_Socket
) s
;
121 sk_set_private_ptr(ps
->sub_socket
, ptr
);
124 static void * sk_proxy_get_private_ptr (Socket s
)
126 Proxy_Socket ps
= (Proxy_Socket
) s
;
127 return sk_get_private_ptr(ps
->sub_socket
);
130 static void sk_proxy_set_frozen (Socket s
, int is_frozen
)
132 Proxy_Socket ps
= (Proxy_Socket
) s
;
134 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
135 ps
->freeze
= is_frozen
;
138 sk_set_frozen(ps
->sub_socket
, is_frozen
);
141 static char * sk_proxy_socket_error (Socket s
)
143 Proxy_Socket ps
= (Proxy_Socket
) s
;
144 if (ps
->error
!= NULL
|| ps
->sub_socket
== NULL
) {
147 return sk_socket_error(ps
->sub_socket
);
150 /* basic proxy plug functions */
152 static int plug_proxy_closing (Plug p
, char *error_msg
,
153 int error_code
, int calling_back
)
155 Proxy_Plug pp
= (Proxy_Plug
) p
;
156 Proxy_Socket ps
= pp
->proxy_socket
;
158 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
159 ps
->closing_error_msg
= error_msg
;
160 ps
->closing_error_code
= error_code
;
161 ps
->closing_calling_back
= calling_back
;
162 return ps
->negotiate(ps
, PROXY_CHANGE_CLOSING
);
164 return plug_closing(ps
->plug
, error_msg
,
165 error_code
, calling_back
);
168 static int plug_proxy_receive (Plug p
, int urgent
, char *data
, int len
)
170 Proxy_Plug pp
= (Proxy_Plug
) p
;
171 Proxy_Socket ps
= pp
->proxy_socket
;
173 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
174 /* we will lose the urgentness of this data, but since most,
175 * if not all, of this data will be consumed by the negotiation
176 * process, hopefully it won't affect the protocol above us
178 bufchain_add(&ps
->pending_input_data
, data
, len
);
179 ps
->receive_urgent
= urgent
;
180 ps
->receive_data
= data
;
181 ps
->receive_len
= len
;
182 return ps
->negotiate(ps
, PROXY_CHANGE_RECEIVE
);
184 return plug_receive(ps
->plug
, urgent
, data
, len
);
187 static void plug_proxy_sent (Plug p
, int bufsize
)
189 Proxy_Plug pp
= (Proxy_Plug
) p
;
190 Proxy_Socket ps
= pp
->proxy_socket
;
192 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
193 ps
->sent_bufsize
= bufsize
;
194 ps
->negotiate(ps
, PROXY_CHANGE_SENT
);
197 plug_sent(ps
->plug
, bufsize
);
200 static int plug_proxy_accepting (Plug p
, void *sock
)
202 Proxy_Plug pp
= (Proxy_Plug
) p
;
203 Proxy_Socket ps
= pp
->proxy_socket
;
205 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
206 ps
->accepting_sock
= sock
;
207 return ps
->negotiate(ps
, PROXY_CHANGE_ACCEPTING
);
209 return plug_accepting(ps
->plug
, sock
);
212 static int proxy_for_destination (SockAddr addr
, char * hostname
, int port
)
216 int hostip_len
, hostname_len
;
219 /* we want a string representation of the IP address for comparisons */
220 sk_getaddr(addr
, hostip
, 64);
222 hostip_len
= strlen(hostip
);
223 hostname_len
= strlen(hostname
);
225 exclude_list
= cfg
.proxy_exclude_list
;
227 /* now parse the exclude list, and see if either our IP
228 * or hostname matches anything in it.
231 while (exclude_list
[s
]) {
232 while (exclude_list
[s
] &&
233 (isspace(exclude_list
[s
]) ||
234 exclude_list
[s
] == ',')) s
++;
236 if (!exclude_list
[s
]) break;
240 while (exclude_list
[e
] &&
241 (isalnum(exclude_list
[e
]) ||
242 exclude_list
[e
] == '-' ||
243 exclude_list
[e
] == '.' ||
244 exclude_list
[e
] == '*')) e
++;
246 if (exclude_list
[s
] == '*') {
247 /* wildcard at beginning of entry */
249 if (strnicmp(hostip
+ hostip_len
- (e
- s
- 1),
250 exclude_list
+ s
+ 1, e
- s
- 1) == 0 ||
251 strnicmp(hostname
+ hostname_len
- (e
- s
- 1),
252 exclude_list
+ s
+ 1, e
- s
- 1) == 0)
253 return 0; /* IP/hostname range excluded. do not use proxy. */
255 } else if (exclude_list
[e
-1] == '*') {
256 /* wildcard at end of entry */
258 if (strnicmp(hostip
, exclude_list
+ s
, e
- s
- 1) == 0 ||
259 strnicmp(hostname
, exclude_list
+ s
, e
- s
- 1) == 0)
260 return 0; /* IP/hostname range excluded. do not use proxy. */
263 /* no wildcard at either end, so let's try an absolute
264 * match (ie. a specific IP)
267 if (stricmp(hostip
, exclude_list
+ s
) == 0)
268 return 0; /* IP/hostname excluded. do not use proxy. */
269 if (stricmp(hostname
, exclude_list
+ s
) == 0)
270 return 0; /* IP/hostname excluded. do not use proxy. */
276 /* no matches in the exclude list, so use the proxy */
280 Socket
new_connection(SockAddr addr
, char *hostname
,
281 int port
, int privport
,
282 int oobinline
, int nodelay
, Plug plug
)
284 static struct socket_function_table socket_fn_table
= {
290 sk_proxy_set_private_ptr
,
291 sk_proxy_get_private_ptr
,
293 sk_proxy_socket_error
296 static struct plug_function_table plug_fn_table
= {
303 if (cfg
.proxy_type
!= PROXY_NONE
&&
304 proxy_for_destination(addr
, hostname
, port
))
309 char * proxy_canonical_name
;
311 ret
= smalloc(sizeof(struct Socket_proxy_tag
));
312 ret
->fn
= &socket_fn_table
;
314 ret
->remote_addr
= addr
;
315 ret
->remote_port
= port
;
317 bufchain_init(&ret
->pending_input_data
);
318 bufchain_init(&ret
->pending_output_data
);
319 bufchain_init(&ret
->pending_oob_output_data
);
321 ret
->sub_socket
= NULL
;
322 ret
->state
= PROXY_STATE_NEW
;
324 if (cfg
.proxy_type
== PROXY_HTTP
) {
325 ret
->negotiate
= proxy_http_negotiate
;
326 } else if (cfg
.proxy_type
== PROXY_SOCKS
) {
327 if (cfg
.proxy_socks_version
== 4)
328 ret
->negotiate
= proxy_socks4_negotiate
;
330 ret
->negotiate
= proxy_socks5_negotiate
;
331 } else if (cfg
.proxy_type
== PROXY_TELNET
) {
332 ret
->negotiate
= proxy_telnet_negotiate
;
334 ret
->error
= "Proxy error: Unknown proxy method";
338 /* create the proxy plug to map calls from the actual
339 * socket into our proxy socket layer */
340 pplug
= smalloc(sizeof(struct Plug_proxy_tag
));
341 pplug
->fn
= &plug_fn_table
;
342 pplug
->proxy_socket
= ret
;
345 proxy_addr
= sk_namelookup(cfg
.proxy_host
,
346 &proxy_canonical_name
);
347 sfree(proxy_canonical_name
);
349 /* create the actual socket we will be using,
350 * connected to our proxy server and port.
352 ret
->sub_socket
= sk_new(proxy_addr
, cfg
.proxy_port
,
354 nodelay
, (Plug
) pplug
);
355 if (sk_socket_error(ret
->sub_socket
) != NULL
)
358 sk_addr_free(proxy_addr
);
360 /* start the proxy negotiation process... */
361 sk_set_frozen(ret
->sub_socket
, 0);
362 ret
->negotiate(ret
, PROXY_CHANGE_NEW
);
367 /* no proxy, so just return the direct socket */
368 return sk_new(addr
, port
, privport
, oobinline
, nodelay
, plug
);
371 Socket
new_listener(int port
, Plug plug
, int local_host_only
)
373 /* TODO: SOCKS (and potentially others) support inbound
374 * TODO: connections via the proxy. support them.
377 return sk_newlistener(port
, plug
, local_host_only
);
380 /* ----------------------------------------------------------------------
381 * HTTP CONNECT proxy type.
384 static int get_line_end (char * data
, int len
)
390 if (data
[off
] == '\n') {
391 /* we have a newline */
394 /* is that the only thing on this line? */
395 if (off
<= 2) return off
;
397 /* if not, then there is the possibility that this header
398 * continues onto the next line, if it starts with a space
403 data
[off
+1] != ' ' &&
404 data
[off
+1] != '\t') return off
;
406 /* the line does continue, so we have to keep going
407 * until we see an the header's "real" end of line.
418 int proxy_http_negotiate (Proxy_Socket p
, int change
)
420 if (p
->state
== PROXY_STATE_NEW
) {
421 /* we are just beginning the proxy negotiate process,
422 * so we'll send off the initial bits of the request.
423 * for this proxy method, it's just a simple HTTP
426 char buf
[256], dest
[64];
428 sk_getaddr(p
->remote_addr
, dest
, 64);
430 sprintf(buf
, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
431 dest
, p
->remote_port
, dest
, p
->remote_port
);
432 sk_write(p
->sub_socket
, buf
, strlen(buf
));
434 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
435 char buf
[sizeof(cfg
.proxy_username
)+sizeof(cfg
.proxy_password
)];
436 char buf2
[sizeof(buf
)*4/3 + 100];
438 sprintf(buf
, "%s:%s", cfg
.proxy_username
, cfg
.proxy_password
);
440 sprintf(buf2
, "Proxy-Authorization: basic ");
441 for (i
= 0, j
= strlen(buf2
); i
< len
; i
+= 3, j
+= 4)
442 base64_encode_atom(buf
+i
, (len
-i
> 3 ?
3 : len
-i
), buf2
+j
);
443 strcpy(buf2
+j
, "\r\n");
444 sk_write(p
->sub_socket
, buf2
, strlen(buf2
));
447 sprintf(buf
, "\r\n");
448 sk_write(p
->sub_socket
, buf
, strlen(buf
));
454 if (change
== PROXY_CHANGE_CLOSING
) {
455 /* if our proxy negotiation process involves closing and opening
456 * new sockets, then we would want to intercept this closing
457 * callback when we were expecting it. if we aren't anticipating
458 * a socket close, then some error must have occurred. we'll
459 * just pass those errors up to the backend.
461 return plug_closing(p
->plug
, p
->closing_error_msg
,
462 p
->closing_error_code
,
463 p
->closing_calling_back
);
466 if (change
== PROXY_CHANGE_SENT
) {
467 /* some (or all) of what we wrote to the proxy was sent.
468 * we don't do anything new, however, until we receive the
469 * proxy's response. we might want to set a timer so we can
470 * timeout the proxy negotiation after a while...
475 if (change
== PROXY_CHANGE_ACCEPTING
) {
476 /* we should _never_ see this, as we are using our socket to
477 * connect to a proxy, not accepting inbound connections.
478 * what should we do? close the socket with an appropriate
481 return plug_accepting(p
->plug
, p
->accepting_sock
);
484 if (change
== PROXY_CHANGE_RECEIVE
) {
485 /* we have received data from the underlying socket, which
486 * we'll need to parse, process, and respond to appropriately.
495 int min_ver
, maj_ver
, status
;
497 /* get the status line */
498 len
= bufchain_size(&p
->pending_input_data
);
499 assert(len
> 0); /* or we wouldn't be here */
501 bufchain_fetch(&p
->pending_input_data
, data
, len
);
503 eol
= get_line_end(data
, len
);
510 /* We can't rely on whether the %n incremented the sscanf return */
511 if (sscanf((char *)data
, "HTTP/%i.%i %n",
512 &maj_ver
, &min_ver
, &status
) < 2 || status
== -1) {
513 plug_closing(p
->plug
, "Proxy error: HTTP response was absent",
514 PROXY_ERROR_GENERAL
, 0);
519 /* remove the status line from the input buffer. */
520 bufchain_consume(&p
->pending_input_data
, eol
);
521 if (data
[status
] != '2') {
525 while (eol
> status
&&
526 (data
[eol
-1] == '\r' || data
[eol
-1] == '\n'))
528 sprintf(buf
, "Proxy error: %.900s",
530 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
542 /* get headers. we're done when we get a
543 * header of length 2, (ie. just "\r\n")
546 len
= bufchain_size(&p
->pending_input_data
);
547 assert(len
> 0); /* or we wouldn't be here */
550 bufchain_fetch(&p
->pending_input_data
, data
, len
);
552 eol
= get_line_end(datap
, len
);
559 bufchain_consume(&p
->pending_input_data
, eol
);
561 eol
= get_line_end(datap
, len
);
566 bufchain_consume(&p
->pending_input_data
, 2);
568 /* proxy activate will have dealt with
569 * whatever is left of the buffer */
579 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
580 PROXY_ERROR_UNEXPECTED
, 0);
584 /* ----------------------------------------------------------------------
588 /* SOCKS version 4 */
589 int proxy_socks4_negotiate (Proxy_Socket p
, int change
)
591 if (p
->state
== PROXY_CHANGE_NEW
) {
594 * version number (1 byte) = 4
595 * command code (1 byte)
598 * dest. port (2 bytes) [network order]
599 * dest. address (4 bytes)
600 * user ID (variable length, null terminated string)
606 if (sk_addrtype(p
->remote_addr
) != AF_INET
) {
607 plug_closing(p
->plug
, "Proxy error: SOCKS version 4 does"
608 " not support IPv6", PROXY_ERROR_GENERAL
, 0);
612 length
= strlen(cfg
.proxy_username
) + 9;
613 command
= (char*) malloc(length
);
614 strcpy(command
+ 8, cfg
.proxy_username
);
616 command
[0] = 4; /* version 4 */
617 command
[1] = 1; /* CONNECT command */
620 command
[2] = (char) (p
->remote_port
>> 8) & 0xff;
621 command
[3] = (char) p
->remote_port
& 0xff;
624 sk_addrcopy(p
->remote_addr
, command
+ 4);
626 sk_write(p
->sub_socket
, command
, length
);
633 if (change
== PROXY_CHANGE_CLOSING
) {
634 /* if our proxy negotiation process involves closing and opening
635 * new sockets, then we would want to intercept this closing
636 * callback when we were expecting it. if we aren't anticipating
637 * a socket close, then some error must have occurred. we'll
638 * just pass those errors up to the backend.
640 return plug_closing(p
->plug
, p
->closing_error_msg
,
641 p
->closing_error_code
,
642 p
->closing_calling_back
);
645 if (change
== PROXY_CHANGE_SENT
) {
646 /* some (or all) of what we wrote to the proxy was sent.
647 * we don't do anything new, however, until we receive the
648 * proxy's response. we might want to set a timer so we can
649 * timeout the proxy negotiation after a while...
654 if (change
== PROXY_CHANGE_ACCEPTING
) {
655 /* we should _never_ see this, as we are using our socket to
656 * connect to a proxy, not accepting inbound connections.
657 * what should we do? close the socket with an appropriate
660 return plug_accepting(p
->plug
, p
->accepting_sock
);
663 if (change
== PROXY_CHANGE_RECEIVE
) {
664 /* we have received data from the underlying socket, which
665 * we'll need to parse, process, and respond to appropriately.
670 * version number (1 byte) = 4
671 * reply code (1 byte)
672 * 90 = request granted
673 * 91 = request rejected or failed
674 * 92 = request rejected due to lack of IDENTD on client
675 * 93 = request rejected due to difference in user ID
676 * (what we sent vs. what IDENTD said)
677 * dest. port (2 bytes)
678 * dest. address (4 bytes)
683 if (bufchain_size(&p
->pending_input_data
) < 8)
684 return 1; /* not got anything yet */
686 /* get the response */
687 bufchain_fetch(&p
->pending_input_data
, data
, 8);
690 plug_closing(p
->plug
, "Proxy error: SOCKS proxy responded with "
691 "unexpected reply code version",
692 PROXY_ERROR_GENERAL
, 0);
700 plug_closing(p
->plug
, "Proxy error: SOCKS server wanted IDENTD on client",
701 PROXY_ERROR_GENERAL
, 0);
704 plug_closing(p
->plug
, "Proxy error: Username and IDENTD on client don't agree",
705 PROXY_ERROR_GENERAL
, 0);
709 plug_closing(p
->plug
, "Proxy error: Error while communicating with proxy",
710 PROXY_ERROR_GENERAL
, 0);
716 bufchain_consume(&p
->pending_input_data
, 8);
720 /* proxy activate will have dealt with
721 * whatever is left of the buffer */
726 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
727 PROXY_ERROR_UNEXPECTED
, 0);
731 /* SOCKS version 5 */
732 int proxy_socks5_negotiate (Proxy_Socket p
, int change
)
734 if (p
->state
== PROXY_CHANGE_NEW
) {
737 * version number (1 byte) = 5
738 * number of available authentication methods (1 byte)
739 * available authentication methods (1 byte * previous value)
740 * authentication methods:
741 * 0x00 = no authentication
743 * 0x02 = username/password
750 command
[0] = 5; /* version 5 */
751 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
752 command
[1] = 2; /* two methods supported: */
753 command
[2] = 0x00; /* no authentication */
754 command
[3] = 0x02; /* username/password */
757 command
[1] = 1; /* one methods supported: */
758 command
[2] = 0x00; /* no authentication */
762 sk_write(p
->sub_socket
, command
, len
);
768 if (change
== PROXY_CHANGE_CLOSING
) {
769 /* if our proxy negotiation process involves closing and opening
770 * new sockets, then we would want to intercept this closing
771 * callback when we were expecting it. if we aren't anticipating
772 * a socket close, then some error must have occurred. we'll
773 * just pass those errors up to the backend.
775 return plug_closing(p
->plug
, p
->closing_error_msg
,
776 p
->closing_error_code
,
777 p
->closing_calling_back
);
780 if (change
== PROXY_CHANGE_SENT
) {
781 /* some (or all) of what we wrote to the proxy was sent.
782 * we don't do anything new, however, until we receive the
783 * proxy's response. we might want to set a timer so we can
784 * timeout the proxy negotiation after a while...
789 if (change
== PROXY_CHANGE_ACCEPTING
) {
790 /* we should _never_ see this, as we are using our socket to
791 * connect to a proxy, not accepting inbound connections.
792 * what should we do? close the socket with an appropriate
795 return plug_accepting(p
->plug
, p
->accepting_sock
);
798 if (change
== PROXY_CHANGE_RECEIVE
) {
799 /* we have received data from the underlying socket, which
800 * we'll need to parse, process, and respond to appropriately.
806 * version number (1 byte) = 5
807 * authentication method (1 byte)
808 * authentication methods:
809 * 0x00 = no authentication
811 * 0x02 = username/password
813 * 0xff = no acceptable methods
817 if (bufchain_size(&p
->pending_input_data
) < 2)
818 return 1; /* not got anything yet */
820 /* get the response */
821 bufchain_fetch(&p
->pending_input_data
, data
, 2);
824 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned unexpected version",
825 PROXY_ERROR_GENERAL
, 0);
829 if (data
[1] == 0x00) p
->state
= 2; /* no authentication needed */
830 else if (data
[1] == 0x01) p
->state
= 4; /* GSSAPI authentication */
831 else if (data
[1] == 0x02) p
->state
= 5; /* username/password authentication */
832 else if (data
[1] == 0x03) p
->state
= 6; /* CHAP authentication */
834 plug_closing(p
->plug
, "Proxy error: SOCKS proxy did not accept our authentication",
835 PROXY_ERROR_GENERAL
, 0);
838 bufchain_consume(&p
->pending_input_data
, 2);
843 /* password authentication reply format:
844 * version number (1 bytes) = 1
845 * reply code (1 byte)
851 if (bufchain_size(&p
->pending_input_data
) < 2)
852 return 1; /* not got anything yet */
854 /* get the response */
855 bufchain_fetch(&p
->pending_input_data
, data
, 2);
858 plug_closing(p
->plug
, "Proxy error: SOCKS password "
859 "subnegotiation contained wrong version number",
860 PROXY_ERROR_GENERAL
, 0);
866 plug_closing(p
->plug
, "Proxy error: SOCKS proxy refused"
867 " password authentication",
868 PROXY_ERROR_GENERAL
, 0);
872 bufchain_consume(&p
->pending_input_data
, 2);
873 p
->state
= 2; /* now proceed as authenticated */
879 * version number (1 byte) = 5
880 * command code (1 byte)
884 * reserved (1 byte) = 0x00
885 * address type (1 byte)
887 * 3 = domainname (first byte has length, no terminating null)
889 * dest. address (variable)
890 * dest. port (2 bytes) [network order]
896 if (sk_addrtype(p
->remote_addr
) == AF_INET
) {
898 command
[3] = 1; /* IPv4 */
901 command
[3] = 4; /* IPv6 */
904 command
[0] = 5; /* version 5 */
905 command
[1] = 1; /* CONNECT command */
909 sk_addrcopy(p
->remote_addr
, command
+4);
912 command
[len
-2] = (char) (p
->remote_port
>> 8) & 0xff;
913 command
[len
-1] = (char) p
->remote_port
& 0xff;
915 sk_write(p
->sub_socket
, command
, len
);
924 * version number (1 bytes) = 5
925 * reply code (1 byte)
927 * 1 = general SOCKS server failure
928 * 2 = connection not allowed by ruleset
929 * 3 = network unreachable
930 * 4 = host unreachable
931 * 5 = connection refused
933 * 7 = command not supported
934 * 8 = address type not supported
935 * reserved (1 byte) = x00
936 * address type (1 byte)
938 * 3 = domainname (first byte has length, no terminating null)
940 * server bound address (variable)
941 * server bound port (2 bytes) [network order]
946 /* First 5 bytes of packet are enough to tell its length. */
947 if (bufchain_size(&p
->pending_input_data
) < 5)
948 return 1; /* not got anything yet */
950 /* get the response */
951 bufchain_fetch(&p
->pending_input_data
, data
, 5);
954 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned wrong version number",
955 PROXY_ERROR_GENERAL
, 0);
962 strcpy(buf
, "Proxy error: ");
965 case 1: strcat(buf
, "General SOCKS server failure"); break;
966 case 2: strcat(buf
, "Connection not allowed by ruleset"); break;
967 case 3: strcat(buf
, "Network unreachable"); break;
968 case 4: strcat(buf
, "Host unreachable"); break;
969 case 5: strcat(buf
, "Connection refused"); break;
970 case 6: strcat(buf
, "TTL expired"); break;
971 case 7: strcat(buf
, "Command not supported"); break;
972 case 8: strcat(buf
, "Address type not supported"); break;
973 default: sprintf(buf
+strlen(buf
),
974 "Unrecognised SOCKS error code %d",
978 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
984 * Eat the rest of the reply packet.
986 len
= 6; /* first 4 bytes, last 2 */
988 case 1: len
+= 4; break; /* IPv4 address */
989 case 4: len
+= 16; break;/* IPv6 address */
990 case 3: len
+= (unsigned char)data
[4]; break; /* domain name */
992 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned "
993 "unrecognised address format",
994 PROXY_ERROR_GENERAL
, 0);
997 if (bufchain_size(&p
->pending_input_data
) < len
)
998 return 1; /* not got whole reply yet */
999 bufchain_consume(&p
->pending_input_data
, len
);
1006 if (p
->state
== 4) {
1007 /* TODO: Handle GSSAPI authentication */
1008 plug_closing(p
->plug
, "Proxy error: We don't support GSSAPI authentication",
1009 PROXY_ERROR_GENERAL
, 0);
1013 if (p
->state
== 5) {
1014 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
1015 char userpwbuf
[514];
1017 ulen
= strlen(cfg
.proxy_username
);
1018 if (ulen
> 255) ulen
= 255; if (ulen
< 1) ulen
= 1;
1019 plen
= strlen(cfg
.proxy_password
);
1020 if (plen
> 255) plen
= 255; if (plen
< 1) plen
= 1;
1021 userpwbuf
[0] = 1; /* version number of subnegotiation */
1022 userpwbuf
[1] = ulen
;
1023 memcpy(userpwbuf
+2, cfg
.proxy_username
, ulen
);
1024 userpwbuf
[ulen
+2] = plen
;
1025 memcpy(userpwbuf
+ulen
+3, cfg
.proxy_password
, plen
);
1026 sk_write(p
->sub_socket
, userpwbuf
, ulen
+ plen
+ 3);
1029 plug_closing(p
->plug
, "Proxy error: Server chose "
1030 "username/password authentication but we "
1032 PROXY_ERROR_GENERAL
, 0);
1036 if (p
->state
== 6) {
1037 /* TODO: Handle CHAP authentication */
1038 plug_closing(p
->plug
, "Proxy error: We don't support CHAP authentication",
1039 PROXY_ERROR_GENERAL
, 0);
1045 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1046 PROXY_ERROR_UNEXPECTED
, 0);
1050 /* ----------------------------------------------------------------------
1051 * `Telnet' proxy type.
1053 * (This is for ad-hoc proxies where you connect to the proxy's
1054 * telnet port and send a command such as `connect host port'. The
1055 * command is configurable, since this proxy type is typically not
1056 * standardised or at all well-defined.)
1059 int proxy_telnet_negotiate (Proxy_Socket p
, int change
)
1061 if (p
->state
== PROXY_CHANGE_NEW
) {
1065 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
1066 * %%, %host, and %port
1069 while (cfg
.proxy_telnet_command
[eo
] != 0) {
1071 /* scan forward until we hit end-of-line,
1072 * or an escape character (\ or %) */
1073 while (cfg
.proxy_telnet_command
[eo
] != 0 &&
1074 cfg
.proxy_telnet_command
[eo
] != '%' &&
1075 cfg
.proxy_telnet_command
[eo
] != '\\') eo
++;
1077 /* if we hit eol, break out of our escaping loop */
1078 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
1080 /* if there was any unescaped text before the escape
1081 * character, send that now */
1083 sk_write(p
->sub_socket
,
1084 cfg
.proxy_telnet_command
+ so
, eo
- so
);
1089 /* if the escape character was the last character of
1090 * the line, we'll just stop and send it. */
1091 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
1093 if (cfg
.proxy_telnet_command
[so
] == '\\') {
1095 /* we recognize \\, \%, \r, \n, \t, \x??.
1096 * anything else, we just send unescaped (including the \).
1099 switch (cfg
.proxy_telnet_command
[eo
]) {
1102 sk_write(p
->sub_socket
, "\\", 1);
1107 sk_write(p
->sub_socket
, "%%", 1);
1112 sk_write(p
->sub_socket
, "\r", 1);
1117 sk_write(p
->sub_socket
, "\n", 1);
1122 sk_write(p
->sub_socket
, "\t", 1);
1129 /* escaped hexadecimal value (ie. \xff) */
1130 unsigned char v
= 0;
1135 if (cfg
.proxy_telnet_command
[eo
] >= '0' &&
1136 cfg
.proxy_telnet_command
[eo
] <= '9')
1137 v
+= cfg
.proxy_telnet_command
[eo
] - '0';
1138 else if (cfg
.proxy_telnet_command
[eo
] >= 'a' &&
1139 cfg
.proxy_telnet_command
[eo
] <= 'f')
1140 v
+= cfg
.proxy_telnet_command
[eo
] - 'a' + 10;
1141 else if (cfg
.proxy_telnet_command
[eo
] >= 'A' &&
1142 cfg
.proxy_telnet_command
[eo
] <= 'F')
1143 v
+= cfg
.proxy_telnet_command
[eo
] - 'A' + 10;
1145 /* non hex character, so we abort and just
1146 * send the whole thing unescaped (including \x)
1148 sk_write(p
->sub_socket
, "\\", 1);
1153 /* we only extract two hex characters */
1155 sk_write(p
->sub_socket
, &v
, 1);
1167 sk_write(p
->sub_socket
,
1168 cfg
.proxy_telnet_command
+ so
, 2);
1174 /* % escape. we recognize %%, %host, %port. anything else,
1175 * we just send unescaped (including the %). */
1177 if (cfg
.proxy_telnet_command
[eo
] == '%') {
1178 sk_write(p
->sub_socket
, "%", 1);
1181 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1184 sk_getaddr(p
->remote_addr
, dest
, 64);
1185 sk_write(p
->sub_socket
, dest
, strlen(dest
));
1188 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1191 sprintf(port
, "%i", p
->remote_port
);
1192 sk_write(p
->sub_socket
, port
, strlen(port
));
1196 /* we don't escape this, so send the % now, and
1197 * don't advance eo, so that we'll consider the
1198 * text immediately following the % as unescaped.
1200 sk_write(p
->sub_socket
, "%", 1);
1204 /* resume scanning for additional escapes after this one. */
1208 /* if there is any unescaped text at the end of the line, send it */
1210 sk_write(p
->sub_socket
, cfg
.proxy_telnet_command
+ so
, eo
- so
);
1217 if (change
== PROXY_CHANGE_CLOSING
) {
1218 /* if our proxy negotiation process involves closing and opening
1219 * new sockets, then we would want to intercept this closing
1220 * callback when we were expecting it. if we aren't anticipating
1221 * a socket close, then some error must have occurred. we'll
1222 * just pass those errors up to the backend.
1224 return plug_closing(p
->plug
, p
->closing_error_msg
,
1225 p
->closing_error_code
,
1226 p
->closing_calling_back
);
1229 if (change
== PROXY_CHANGE_SENT
) {
1230 /* some (or all) of what we wrote to the proxy was sent.
1231 * we don't do anything new, however, until we receive the
1232 * proxy's response. we might want to set a timer so we can
1233 * timeout the proxy negotiation after a while...
1238 if (change
== PROXY_CHANGE_ACCEPTING
) {
1239 /* we should _never_ see this, as we are using our socket to
1240 * connect to a proxy, not accepting inbound connections.
1241 * what should we do? close the socket with an appropriate
1244 return plug_accepting(p
->plug
, p
->accepting_sock
);
1247 if (change
== PROXY_CHANGE_RECEIVE
) {
1248 /* we have received data from the underlying socket, which
1249 * we'll need to parse, process, and respond to appropriately.
1254 /* proxy activate will have dealt with
1255 * whatever is left of the buffer */
1259 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1260 PROXY_ERROR_UNEXPECTED
, 0);