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
17 #define do_proxy_dns \
18 (cfg.proxy_dns == 2 || \
19 (cfg.proxy_dns == 1 && cfg.proxy_type != PROXY_SOCKS))
22 * Call this when proxy negotiation is complete, so that this
23 * socket can begin working normally.
25 void proxy_activate (Proxy_Socket p
)
29 long output_before
, output_after
;
31 p
->state
= PROXY_STATE_ACTIVE
;
33 /* we want to ignore new receive events until we have sent
34 * all of our buffered receive data.
36 sk_set_frozen(p
->sub_socket
, 1);
38 /* how many bytes of output have we buffered? */
39 output_before
= bufchain_size(&p
->pending_oob_output_data
) +
40 bufchain_size(&p
->pending_output_data
);
41 /* and keep track of how many bytes do not get sent. */
44 /* send buffered OOB writes */
45 while (bufchain_size(&p
->pending_oob_output_data
) > 0) {
46 bufchain_prefix(&p
->pending_oob_output_data
, &data
, &len
);
47 output_after
+= sk_write_oob(p
->sub_socket
, data
, len
);
48 bufchain_consume(&p
->pending_oob_output_data
, len
);
51 /* send buffered normal writes */
52 while (bufchain_size(&p
->pending_output_data
) > 0) {
53 bufchain_prefix(&p
->pending_output_data
, &data
, &len
);
54 output_after
+= sk_write(p
->sub_socket
, data
, len
);
55 bufchain_consume(&p
->pending_output_data
, len
);
58 /* if we managed to send any data, let the higher levels know. */
59 if (output_after
< output_before
)
60 plug_sent(p
->plug
, output_after
);
62 /* if we were asked to flush the output during
63 * the proxy negotiation process, do so now.
65 if (p
->pending_flush
) sk_flush(p
->sub_socket
);
67 /* if the backend wanted the socket unfrozen, try to unfreeze.
68 * our set_frozen handler will flush buffered receive data before
69 * unfreezing the actual underlying socket.
72 sk_set_frozen((Socket
)p
, 0);
75 /* basic proxy socket functions */
77 static Plug
sk_proxy_plug (Socket s
, Plug p
)
79 Proxy_Socket ps
= (Proxy_Socket
) s
;
86 static void sk_proxy_close (Socket s
)
88 Proxy_Socket ps
= (Proxy_Socket
) s
;
90 sk_close(ps
->sub_socket
);
94 static int sk_proxy_write (Socket s
, char *data
, int len
)
96 Proxy_Socket ps
= (Proxy_Socket
) s
;
98 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
99 bufchain_add(&ps
->pending_output_data
, data
, len
);
100 return bufchain_size(&ps
->pending_output_data
);
102 return sk_write(ps
->sub_socket
, data
, len
);
105 static int sk_proxy_write_oob (Socket s
, char *data
, int len
)
107 Proxy_Socket ps
= (Proxy_Socket
) s
;
109 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
110 bufchain_clear(&ps
->pending_output_data
);
111 bufchain_clear(&ps
->pending_oob_output_data
);
112 bufchain_add(&ps
->pending_oob_output_data
, data
, len
);
115 return sk_write_oob(ps
->sub_socket
, data
, len
);
118 static void sk_proxy_flush (Socket s
)
120 Proxy_Socket ps
= (Proxy_Socket
) s
;
122 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
123 ps
->pending_flush
= 1;
126 sk_flush(ps
->sub_socket
);
129 static void sk_proxy_set_private_ptr (Socket s
, void *ptr
)
131 Proxy_Socket ps
= (Proxy_Socket
) s
;
132 sk_set_private_ptr(ps
->sub_socket
, ptr
);
135 static void * sk_proxy_get_private_ptr (Socket s
)
137 Proxy_Socket ps
= (Proxy_Socket
) s
;
138 return sk_get_private_ptr(ps
->sub_socket
);
141 static void sk_proxy_set_frozen (Socket s
, int is_frozen
)
143 Proxy_Socket ps
= (Proxy_Socket
) s
;
145 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
146 ps
->freeze
= is_frozen
;
150 /* handle any remaining buffered recv data first */
151 if (bufchain_size(&ps
->pending_input_data
) > 0) {
152 ps
->freeze
= is_frozen
;
154 /* loop while we still have buffered data, and while we are
155 * unfrozen. the plug_receive call in the loop could result
156 * in a call back into this function refreezing the socket,
157 * so we have to check each time.
159 while (!ps
->freeze
&& bufchain_size(&ps
->pending_input_data
) > 0) {
162 bufchain_prefix(&ps
->pending_input_data
, &data
, &len
);
163 plug_receive(ps
->plug
, 0, data
, len
);
164 bufchain_consume(&ps
->pending_input_data
, len
);
167 /* if we're still frozen, we'll have to wait for another
168 * call from the backend to finish unbuffering the data.
170 if (ps
->freeze
) return;
173 sk_set_frozen(ps
->sub_socket
, is_frozen
);
176 static char * sk_proxy_socket_error (Socket s
)
178 Proxy_Socket ps
= (Proxy_Socket
) s
;
179 if (ps
->error
!= NULL
|| ps
->sub_socket
== NULL
) {
182 return sk_socket_error(ps
->sub_socket
);
185 /* basic proxy plug functions */
187 static int plug_proxy_closing (Plug p
, char *error_msg
,
188 int error_code
, int calling_back
)
190 Proxy_Plug pp
= (Proxy_Plug
) p
;
191 Proxy_Socket ps
= pp
->proxy_socket
;
193 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
194 ps
->closing_error_msg
= error_msg
;
195 ps
->closing_error_code
= error_code
;
196 ps
->closing_calling_back
= calling_back
;
197 return ps
->negotiate(ps
, PROXY_CHANGE_CLOSING
);
199 return plug_closing(ps
->plug
, error_msg
,
200 error_code
, calling_back
);
203 static int plug_proxy_receive (Plug p
, int urgent
, char *data
, int len
)
205 Proxy_Plug pp
= (Proxy_Plug
) p
;
206 Proxy_Socket ps
= pp
->proxy_socket
;
208 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
209 /* we will lose the urgentness of this data, but since most,
210 * if not all, of this data will be consumed by the negotiation
211 * process, hopefully it won't affect the protocol above us
213 bufchain_add(&ps
->pending_input_data
, data
, len
);
214 ps
->receive_urgent
= urgent
;
215 ps
->receive_data
= data
;
216 ps
->receive_len
= len
;
217 return ps
->negotiate(ps
, PROXY_CHANGE_RECEIVE
);
219 return plug_receive(ps
->plug
, urgent
, data
, len
);
222 static void plug_proxy_sent (Plug p
, int bufsize
)
224 Proxy_Plug pp
= (Proxy_Plug
) p
;
225 Proxy_Socket ps
= pp
->proxy_socket
;
227 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
228 ps
->sent_bufsize
= bufsize
;
229 ps
->negotiate(ps
, PROXY_CHANGE_SENT
);
232 plug_sent(ps
->plug
, bufsize
);
235 static int plug_proxy_accepting (Plug p
, void *sock
)
237 Proxy_Plug pp
= (Proxy_Plug
) p
;
238 Proxy_Socket ps
= pp
->proxy_socket
;
240 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
241 ps
->accepting_sock
= sock
;
242 return ps
->negotiate(ps
, PROXY_CHANGE_ACCEPTING
);
244 return plug_accepting(ps
->plug
, sock
);
248 * This function can accept a NULL pointer as `addr', in which case
249 * it will only check the host name.
251 static int proxy_for_destination (SockAddr addr
, char * hostname
, int port
)
255 int hostip_len
, hostname_len
;
259 * Check the host name and IP against the hard-coded
260 * representations of `localhost'.
262 if (!cfg
.even_proxy_localhost
&&
263 (sk_hostname_is_local(hostname
) ||
264 (addr
&& sk_address_is_local(addr
))))
265 return 0; /* do not proxy */
267 /* we want a string representation of the IP address for comparisons */
269 sk_getaddr(addr
, hostip
, 64);
270 hostip_len
= strlen(hostip
);
273 hostname_len
= strlen(hostname
);
275 exclude_list
= cfg
.proxy_exclude_list
;
277 /* now parse the exclude list, and see if either our IP
278 * or hostname matches anything in it.
281 while (exclude_list
[s
]) {
282 while (exclude_list
[s
] &&
283 (isspace(exclude_list
[s
]) ||
284 exclude_list
[s
] == ',')) s
++;
286 if (!exclude_list
[s
]) break;
290 while (exclude_list
[e
] &&
291 (isalnum(exclude_list
[e
]) ||
292 exclude_list
[e
] == '-' ||
293 exclude_list
[e
] == '.' ||
294 exclude_list
[e
] == '*')) e
++;
296 if (exclude_list
[s
] == '*') {
297 /* wildcard at beginning of entry */
299 if ((addr
&& strnicmp(hostip
+ hostip_len
- (e
- s
- 1),
300 exclude_list
+ s
+ 1, e
- s
- 1) == 0) ||
301 strnicmp(hostname
+ hostname_len
- (e
- s
- 1),
302 exclude_list
+ s
+ 1, e
- s
- 1) == 0)
303 return 0; /* IP/hostname range excluded. do not use proxy. */
305 } else if (exclude_list
[e
-1] == '*') {
306 /* wildcard at end of entry */
308 if ((addr
&& strnicmp(hostip
, exclude_list
+ s
, e
- s
- 1) == 0) ||
309 strnicmp(hostname
, exclude_list
+ s
, e
- s
- 1) == 0)
310 return 0; /* IP/hostname range excluded. do not use proxy. */
313 /* no wildcard at either end, so let's try an absolute
314 * match (ie. a specific IP)
317 if (addr
&& stricmp(hostip
, exclude_list
+ s
) == 0)
318 return 0; /* IP/hostname excluded. do not use proxy. */
319 if (stricmp(hostname
, exclude_list
+ s
) == 0)
320 return 0; /* IP/hostname excluded. do not use proxy. */
326 /* no matches in the exclude list, so use the proxy */
330 SockAddr
name_lookup(char *host
, int port
, char **canonicalname
)
332 if (cfg
.proxy_type
!= PROXY_NONE
&&
333 do_proxy_dns
&& proxy_for_destination(NULL
, host
, port
)) {
334 *canonicalname
= dupstr(host
);
335 return sk_nonamelookup(host
);
338 return sk_namelookup(host
, canonicalname
);
341 Socket
new_connection(SockAddr addr
, char *hostname
,
342 int port
, int privport
,
343 int oobinline
, int nodelay
, Plug plug
)
345 static const struct socket_function_table socket_fn_table
= {
351 sk_proxy_set_private_ptr
,
352 sk_proxy_get_private_ptr
,
354 sk_proxy_socket_error
357 static const struct plug_function_table plug_fn_table
= {
364 if (cfg
.proxy_type
!= PROXY_NONE
&&
365 proxy_for_destination(addr
, hostname
, port
))
370 char *proxy_canonical_name
, *err
;
372 ret
= smalloc(sizeof(struct Socket_proxy_tag
));
373 ret
->fn
= &socket_fn_table
;
375 ret
->remote_addr
= addr
;
376 ret
->remote_port
= port
;
379 ret
->pending_flush
= 0;
382 bufchain_init(&ret
->pending_input_data
);
383 bufchain_init(&ret
->pending_output_data
);
384 bufchain_init(&ret
->pending_oob_output_data
);
386 ret
->sub_socket
= NULL
;
387 ret
->state
= PROXY_STATE_NEW
;
388 ret
->negotiate
= NULL
;
390 if (cfg
.proxy_type
== PROXY_HTTP
) {
391 ret
->negotiate
= proxy_http_negotiate
;
392 } else if (cfg
.proxy_type
== PROXY_SOCKS
) {
393 if (cfg
.proxy_socks_version
== 4)
394 ret
->negotiate
= proxy_socks4_negotiate
;
396 ret
->negotiate
= proxy_socks5_negotiate
;
397 } else if (cfg
.proxy_type
== PROXY_TELNET
) {
398 ret
->negotiate
= proxy_telnet_negotiate
;
400 ret
->error
= "Proxy error: Unknown proxy method";
404 /* create the proxy plug to map calls from the actual
405 * socket into our proxy socket layer */
406 pplug
= smalloc(sizeof(struct Plug_proxy_tag
));
407 pplug
->fn
= &plug_fn_table
;
408 pplug
->proxy_socket
= ret
;
411 proxy_addr
= sk_namelookup(cfg
.proxy_host
,
412 &proxy_canonical_name
);
413 if ((err
= sk_addr_error(proxy_addr
))) {
414 ret
->error
= "Proxy error: Unable to resolve proxy host name";
417 sfree(proxy_canonical_name
);
419 /* create the actual socket we will be using,
420 * connected to our proxy server and port.
422 ret
->sub_socket
= sk_new(proxy_addr
, cfg
.proxy_port
,
424 nodelay
, (Plug
) pplug
);
425 if (sk_socket_error(ret
->sub_socket
) != NULL
)
428 sk_addr_free(proxy_addr
);
430 /* start the proxy negotiation process... */
431 sk_set_frozen(ret
->sub_socket
, 0);
432 ret
->negotiate(ret
, PROXY_CHANGE_NEW
);
437 /* no proxy, so just return the direct socket */
438 return sk_new(addr
, port
, privport
, oobinline
, nodelay
, plug
);
441 Socket
new_listener(char *srcaddr
, int port
, Plug plug
, int local_host_only
)
443 /* TODO: SOCKS (and potentially others) support inbound
444 * TODO: connections via the proxy. support them.
447 return sk_newlistener(srcaddr
, port
, plug
, local_host_only
);
450 /* ----------------------------------------------------------------------
451 * HTTP CONNECT proxy type.
454 static int get_line_end (char * data
, int len
)
460 if (data
[off
] == '\n') {
461 /* we have a newline */
464 /* is that the only thing on this line? */
465 if (off
<= 2) return off
;
467 /* if not, then there is the possibility that this header
468 * continues onto the next line, if it starts with a space
473 data
[off
+1] != ' ' &&
474 data
[off
+1] != '\t') return off
;
476 /* the line does continue, so we have to keep going
477 * until we see an the header's "real" end of line.
488 int proxy_http_negotiate (Proxy_Socket p
, int change
)
490 if (p
->state
== PROXY_STATE_NEW
) {
491 /* we are just beginning the proxy negotiate process,
492 * so we'll send off the initial bits of the request.
493 * for this proxy method, it's just a simple HTTP
496 char *buf
, dest
[512];
498 sk_getaddr(p
->remote_addr
, dest
, lenof(dest
));
500 buf
= dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
501 dest
, p
->remote_port
, dest
, p
->remote_port
);
502 sk_write(p
->sub_socket
, buf
, strlen(buf
));
505 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
506 char buf
[sizeof(cfg
.proxy_username
)+sizeof(cfg
.proxy_password
)];
507 char buf2
[sizeof(buf
)*4/3 + 100];
509 sprintf(buf
, "%s:%s", cfg
.proxy_username
, cfg
.proxy_password
);
511 sprintf(buf2
, "Proxy-Authorization: basic ");
512 for (i
= 0, j
= strlen(buf2
); i
< len
; i
+= 3, j
+= 4)
513 base64_encode_atom(buf
+i
, (len
-i
> 3 ?
3 : len
-i
), buf2
+j
);
514 strcpy(buf2
+j
, "\r\n");
515 sk_write(p
->sub_socket
, buf2
, strlen(buf2
));
518 sk_write(p
->sub_socket
, "\r\n", 2);
524 if (change
== PROXY_CHANGE_CLOSING
) {
525 /* if our proxy negotiation process involves closing and opening
526 * new sockets, then we would want to intercept this closing
527 * callback when we were expecting it. if we aren't anticipating
528 * a socket close, then some error must have occurred. we'll
529 * just pass those errors up to the backend.
531 return plug_closing(p
->plug
, p
->closing_error_msg
,
532 p
->closing_error_code
,
533 p
->closing_calling_back
);
536 if (change
== PROXY_CHANGE_SENT
) {
537 /* some (or all) of what we wrote to the proxy was sent.
538 * we don't do anything new, however, until we receive the
539 * proxy's response. we might want to set a timer so we can
540 * timeout the proxy negotiation after a while...
545 if (change
== PROXY_CHANGE_ACCEPTING
) {
546 /* we should _never_ see this, as we are using our socket to
547 * connect to a proxy, not accepting inbound connections.
548 * what should we do? close the socket with an appropriate
551 return plug_accepting(p
->plug
, p
->accepting_sock
);
554 if (change
== PROXY_CHANGE_RECEIVE
) {
555 /* we have received data from the underlying socket, which
556 * we'll need to parse, process, and respond to appropriately.
565 int min_ver
, maj_ver
, status
;
567 /* get the status line */
568 len
= bufchain_size(&p
->pending_input_data
);
569 assert(len
> 0); /* or we wouldn't be here */
571 bufchain_fetch(&p
->pending_input_data
, data
, len
);
573 eol
= get_line_end(data
, len
);
580 /* We can't rely on whether the %n incremented the sscanf return */
581 if (sscanf((char *)data
, "HTTP/%i.%i %n",
582 &maj_ver
, &min_ver
, &status
) < 2 || status
== -1) {
583 plug_closing(p
->plug
, "Proxy error: HTTP response was absent",
584 PROXY_ERROR_GENERAL
, 0);
589 /* remove the status line from the input buffer. */
590 bufchain_consume(&p
->pending_input_data
, eol
);
591 if (data
[status
] != '2') {
595 while (eol
> status
&&
596 (data
[eol
-1] == '\r' || data
[eol
-1] == '\n'))
598 buf
= dupprintf("Proxy error: %s", data
+status
);
599 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
612 /* get headers. we're done when we get a
613 * header of length 2, (ie. just "\r\n")
616 len
= bufchain_size(&p
->pending_input_data
);
617 assert(len
> 0); /* or we wouldn't be here */
620 bufchain_fetch(&p
->pending_input_data
, data
, len
);
622 eol
= get_line_end(datap
, len
);
629 bufchain_consume(&p
->pending_input_data
, eol
);
632 eol
= get_line_end(datap
, len
);
637 bufchain_consume(&p
->pending_input_data
, 2);
639 /* proxy activate will have dealt with
640 * whatever is left of the buffer */
650 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
651 PROXY_ERROR_UNEXPECTED
, 0);
655 /* ----------------------------------------------------------------------
659 /* SOCKS version 4 */
660 int proxy_socks4_negotiate (Proxy_Socket p
, int change
)
662 if (p
->state
== PROXY_CHANGE_NEW
) {
665 * version number (1 byte) = 4
666 * command code (1 byte)
669 * dest. port (2 bytes) [network order]
670 * dest. address (4 bytes)
671 * user ID (variable length, null terminated string)
674 int length
, type
, namelen
;
675 char *command
, addr
[4], hostname
[512];
677 type
= sk_addrtype(p
->remote_addr
);
678 if (type
== ADDRTYPE_IPV6
) {
679 plug_closing(p
->plug
, "Proxy error: SOCKS version 4 does"
680 " not support IPv6", PROXY_ERROR_GENERAL
, 0);
682 } else if (type
== ADDRTYPE_IPV4
) {
684 sk_addrcopy(p
->remote_addr
, addr
);
685 } else { /* type == ADDRTYPE_NAME */
686 sk_getaddr(p
->remote_addr
, hostname
, lenof(hostname
));
687 namelen
= strlen(hostname
) + 1; /* include the NUL */
688 addr
[0] = addr
[1] = addr
[2] = 0;
692 length
= strlen(cfg
.proxy_username
) + namelen
+ 9;
693 command
= (char*) smalloc(length
);
694 strcpy(command
+ 8, cfg
.proxy_username
);
696 command
[0] = 4; /* version 4 */
697 command
[1] = 1; /* CONNECT command */
700 command
[2] = (char) (p
->remote_port
>> 8) & 0xff;
701 command
[3] = (char) p
->remote_port
& 0xff;
704 memcpy(command
+ 4, addr
, 4);
707 memcpy(command
+ 8 + strlen(cfg
.proxy_username
) + 1,
710 sk_write(p
->sub_socket
, command
, length
);
717 if (change
== PROXY_CHANGE_CLOSING
) {
718 /* if our proxy negotiation process involves closing and opening
719 * new sockets, then we would want to intercept this closing
720 * callback when we were expecting it. if we aren't anticipating
721 * a socket close, then some error must have occurred. we'll
722 * just pass those errors up to the backend.
724 return plug_closing(p
->plug
, p
->closing_error_msg
,
725 p
->closing_error_code
,
726 p
->closing_calling_back
);
729 if (change
== PROXY_CHANGE_SENT
) {
730 /* some (or all) of what we wrote to the proxy was sent.
731 * we don't do anything new, however, until we receive the
732 * proxy's response. we might want to set a timer so we can
733 * timeout the proxy negotiation after a while...
738 if (change
== PROXY_CHANGE_ACCEPTING
) {
739 /* we should _never_ see this, as we are using our socket to
740 * connect to a proxy, not accepting inbound connections.
741 * what should we do? close the socket with an appropriate
744 return plug_accepting(p
->plug
, p
->accepting_sock
);
747 if (change
== PROXY_CHANGE_RECEIVE
) {
748 /* we have received data from the underlying socket, which
749 * we'll need to parse, process, and respond to appropriately.
754 * version number (1 byte) = 4
755 * reply code (1 byte)
756 * 90 = request granted
757 * 91 = request rejected or failed
758 * 92 = request rejected due to lack of IDENTD on client
759 * 93 = request rejected due to difference in user ID
760 * (what we sent vs. what IDENTD said)
761 * dest. port (2 bytes)
762 * dest. address (4 bytes)
767 if (bufchain_size(&p
->pending_input_data
) < 8)
768 return 1; /* not got anything yet */
770 /* get the response */
771 bufchain_fetch(&p
->pending_input_data
, data
, 8);
774 plug_closing(p
->plug
, "Proxy error: SOCKS proxy responded with "
775 "unexpected reply code version",
776 PROXY_ERROR_GENERAL
, 0);
784 plug_closing(p
->plug
, "Proxy error: SOCKS server wanted IDENTD on client",
785 PROXY_ERROR_GENERAL
, 0);
788 plug_closing(p
->plug
, "Proxy error: Username and IDENTD on client don't agree",
789 PROXY_ERROR_GENERAL
, 0);
793 plug_closing(p
->plug
, "Proxy error: Error while communicating with proxy",
794 PROXY_ERROR_GENERAL
, 0);
800 bufchain_consume(&p
->pending_input_data
, 8);
804 /* proxy activate will have dealt with
805 * whatever is left of the buffer */
810 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
811 PROXY_ERROR_UNEXPECTED
, 0);
815 /* SOCKS version 5 */
816 int proxy_socks5_negotiate (Proxy_Socket p
, int change
)
818 if (p
->state
== PROXY_CHANGE_NEW
) {
821 * version number (1 byte) = 5
822 * number of available authentication methods (1 byte)
823 * available authentication methods (1 byte * previous value)
824 * authentication methods:
825 * 0x00 = no authentication
827 * 0x02 = username/password
834 command
[0] = 5; /* version 5 */
835 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
836 command
[1] = 2; /* two methods supported: */
837 command
[2] = 0x00; /* no authentication */
838 command
[3] = 0x02; /* username/password */
841 command
[1] = 1; /* one methods supported: */
842 command
[2] = 0x00; /* no authentication */
846 sk_write(p
->sub_socket
, command
, len
);
852 if (change
== PROXY_CHANGE_CLOSING
) {
853 /* if our proxy negotiation process involves closing and opening
854 * new sockets, then we would want to intercept this closing
855 * callback when we were expecting it. if we aren't anticipating
856 * a socket close, then some error must have occurred. we'll
857 * just pass those errors up to the backend.
859 return plug_closing(p
->plug
, p
->closing_error_msg
,
860 p
->closing_error_code
,
861 p
->closing_calling_back
);
864 if (change
== PROXY_CHANGE_SENT
) {
865 /* some (or all) of what we wrote to the proxy was sent.
866 * we don't do anything new, however, until we receive the
867 * proxy's response. we might want to set a timer so we can
868 * timeout the proxy negotiation after a while...
873 if (change
== PROXY_CHANGE_ACCEPTING
) {
874 /* we should _never_ see this, as we are using our socket to
875 * connect to a proxy, not accepting inbound connections.
876 * what should we do? close the socket with an appropriate
879 return plug_accepting(p
->plug
, p
->accepting_sock
);
882 if (change
== PROXY_CHANGE_RECEIVE
) {
883 /* we have received data from the underlying socket, which
884 * we'll need to parse, process, and respond to appropriately.
890 * version number (1 byte) = 5
891 * authentication method (1 byte)
892 * authentication methods:
893 * 0x00 = no authentication
895 * 0x02 = username/password
897 * 0xff = no acceptable methods
901 if (bufchain_size(&p
->pending_input_data
) < 2)
902 return 1; /* not got anything yet */
904 /* get the response */
905 bufchain_fetch(&p
->pending_input_data
, data
, 2);
908 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned unexpected version",
909 PROXY_ERROR_GENERAL
, 0);
913 if (data
[1] == 0x00) p
->state
= 2; /* no authentication needed */
914 else if (data
[1] == 0x01) p
->state
= 4; /* GSSAPI authentication */
915 else if (data
[1] == 0x02) p
->state
= 5; /* username/password authentication */
916 else if (data
[1] == 0x03) p
->state
= 6; /* CHAP authentication */
918 plug_closing(p
->plug
, "Proxy error: SOCKS proxy did not accept our authentication",
919 PROXY_ERROR_GENERAL
, 0);
922 bufchain_consume(&p
->pending_input_data
, 2);
927 /* password authentication reply format:
928 * version number (1 bytes) = 1
929 * reply code (1 byte)
935 if (bufchain_size(&p
->pending_input_data
) < 2)
936 return 1; /* not got anything yet */
938 /* get the response */
939 bufchain_fetch(&p
->pending_input_data
, data
, 2);
942 plug_closing(p
->plug
, "Proxy error: SOCKS password "
943 "subnegotiation contained wrong version number",
944 PROXY_ERROR_GENERAL
, 0);
950 plug_closing(p
->plug
, "Proxy error: SOCKS proxy refused"
951 " password authentication",
952 PROXY_ERROR_GENERAL
, 0);
956 bufchain_consume(&p
->pending_input_data
, 2);
957 p
->state
= 2; /* now proceed as authenticated */
963 * version number (1 byte) = 5
964 * command code (1 byte)
968 * reserved (1 byte) = 0x00
969 * address type (1 byte)
971 * 3 = domainname (first byte has length, no terminating null)
973 * dest. address (variable)
974 * dest. port (2 bytes) [network order]
981 type
= sk_addrtype(p
->remote_addr
);
982 if (type
== ADDRTYPE_IPV4
) {
983 len
= 10; /* 4 hdr + 4 addr + 2 trailer */
984 command
[3] = 1; /* IPv4 */
985 sk_addrcopy(p
->remote_addr
, command
+4);
986 } else if (type
== ADDRTYPE_IPV6
) {
987 len
= 22; /* 4 hdr + 16 addr + 2 trailer */
988 command
[3] = 4; /* IPv6 */
989 sk_addrcopy(p
->remote_addr
, command
+4);
990 } else if (type
== ADDRTYPE_NAME
) {
992 sk_getaddr(p
->remote_addr
, command
+5, 256);
993 command
[4] = strlen(command
+5);
994 len
= 7 + command
[4]; /* 4 hdr, 1 len, N addr, 2 trailer */
997 command
[0] = 5; /* version 5 */
998 command
[1] = 1; /* CONNECT command */
1002 command
[len
-2] = (char) (p
->remote_port
>> 8) & 0xff;
1003 command
[len
-1] = (char) p
->remote_port
& 0xff;
1005 sk_write(p
->sub_socket
, command
, len
);
1011 if (p
->state
== 3) {
1014 * version number (1 bytes) = 5
1015 * reply code (1 byte)
1017 * 1 = general SOCKS server failure
1018 * 2 = connection not allowed by ruleset
1019 * 3 = network unreachable
1020 * 4 = host unreachable
1021 * 5 = connection refused
1023 * 7 = command not supported
1024 * 8 = address type not supported
1025 * reserved (1 byte) = x00
1026 * address type (1 byte)
1028 * 3 = domainname (first byte has length, no terminating null)
1030 * server bound address (variable)
1031 * server bound port (2 bytes) [network order]
1036 /* First 5 bytes of packet are enough to tell its length. */
1037 if (bufchain_size(&p
->pending_input_data
) < 5)
1038 return 1; /* not got anything yet */
1040 /* get the response */
1041 bufchain_fetch(&p
->pending_input_data
, data
, 5);
1044 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned wrong version number",
1045 PROXY_ERROR_GENERAL
, 0);
1052 strcpy(buf
, "Proxy error: ");
1055 case 1: strcat(buf
, "General SOCKS server failure"); break;
1056 case 2: strcat(buf
, "Connection not allowed by ruleset"); break;
1057 case 3: strcat(buf
, "Network unreachable"); break;
1058 case 4: strcat(buf
, "Host unreachable"); break;
1059 case 5: strcat(buf
, "Connection refused"); break;
1060 case 6: strcat(buf
, "TTL expired"); break;
1061 case 7: strcat(buf
, "Command not supported"); break;
1062 case 8: strcat(buf
, "Address type not supported"); break;
1063 default: sprintf(buf
+strlen(buf
),
1064 "Unrecognised SOCKS error code %d",
1068 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
1074 * Eat the rest of the reply packet.
1076 len
= 6; /* first 4 bytes, last 2 */
1078 case 1: len
+= 4; break; /* IPv4 address */
1079 case 4: len
+= 16; break;/* IPv6 address */
1080 case 3: len
+= (unsigned char)data
[4]; break; /* domain name */
1082 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned "
1083 "unrecognised address format",
1084 PROXY_ERROR_GENERAL
, 0);
1087 if (bufchain_size(&p
->pending_input_data
) < len
)
1088 return 1; /* not got whole reply yet */
1089 bufchain_consume(&p
->pending_input_data
, len
);
1096 if (p
->state
== 4) {
1097 /* TODO: Handle GSSAPI authentication */
1098 plug_closing(p
->plug
, "Proxy error: We don't support GSSAPI authentication",
1099 PROXY_ERROR_GENERAL
, 0);
1103 if (p
->state
== 5) {
1104 if (cfg
.proxy_username
[0] || cfg
.proxy_password
[0]) {
1105 char userpwbuf
[514];
1107 ulen
= strlen(cfg
.proxy_username
);
1108 if (ulen
> 255) ulen
= 255; if (ulen
< 1) ulen
= 1;
1109 plen
= strlen(cfg
.proxy_password
);
1110 if (plen
> 255) plen
= 255; if (plen
< 1) plen
= 1;
1111 userpwbuf
[0] = 1; /* version number of subnegotiation */
1112 userpwbuf
[1] = ulen
;
1113 memcpy(userpwbuf
+2, cfg
.proxy_username
, ulen
);
1114 userpwbuf
[ulen
+2] = plen
;
1115 memcpy(userpwbuf
+ulen
+3, cfg
.proxy_password
, plen
);
1116 sk_write(p
->sub_socket
, userpwbuf
, ulen
+ plen
+ 3);
1119 plug_closing(p
->plug
, "Proxy error: Server chose "
1120 "username/password authentication but we "
1122 PROXY_ERROR_GENERAL
, 0);
1126 if (p
->state
== 6) {
1127 /* TODO: Handle CHAP authentication */
1128 plug_closing(p
->plug
, "Proxy error: We don't support CHAP authentication",
1129 PROXY_ERROR_GENERAL
, 0);
1135 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1136 PROXY_ERROR_UNEXPECTED
, 0);
1140 /* ----------------------------------------------------------------------
1141 * `Telnet' proxy type.
1143 * (This is for ad-hoc proxies where you connect to the proxy's
1144 * telnet port and send a command such as `connect host port'. The
1145 * command is configurable, since this proxy type is typically not
1146 * standardised or at all well-defined.)
1149 int proxy_telnet_negotiate (Proxy_Socket p
, int change
)
1151 if (p
->state
== PROXY_CHANGE_NEW
) {
1155 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
1156 * %%, %host, %port, %user, and %pass
1159 while (cfg
.proxy_telnet_command
[eo
] != 0) {
1161 /* scan forward until we hit end-of-line,
1162 * or an escape character (\ or %) */
1163 while (cfg
.proxy_telnet_command
[eo
] != 0 &&
1164 cfg
.proxy_telnet_command
[eo
] != '%' &&
1165 cfg
.proxy_telnet_command
[eo
] != '\\') eo
++;
1167 /* if we hit eol, break out of our escaping loop */
1168 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
1170 /* if there was any unescaped text before the escape
1171 * character, send that now */
1173 sk_write(p
->sub_socket
,
1174 cfg
.proxy_telnet_command
+ so
, eo
- so
);
1179 /* if the escape character was the last character of
1180 * the line, we'll just stop and send it. */
1181 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
1183 if (cfg
.proxy_telnet_command
[so
] == '\\') {
1185 /* we recognize \\, \%, \r, \n, \t, \x??.
1186 * anything else, we just send unescaped (including the \).
1189 switch (cfg
.proxy_telnet_command
[eo
]) {
1192 sk_write(p
->sub_socket
, "\\", 1);
1197 sk_write(p
->sub_socket
, "%%", 1);
1202 sk_write(p
->sub_socket
, "\r", 1);
1207 sk_write(p
->sub_socket
, "\n", 1);
1212 sk_write(p
->sub_socket
, "\t", 1);
1219 /* escaped hexadecimal value (ie. \xff) */
1220 unsigned char v
= 0;
1225 if (cfg
.proxy_telnet_command
[eo
] >= '0' &&
1226 cfg
.proxy_telnet_command
[eo
] <= '9')
1227 v
+= cfg
.proxy_telnet_command
[eo
] - '0';
1228 else if (cfg
.proxy_telnet_command
[eo
] >= 'a' &&
1229 cfg
.proxy_telnet_command
[eo
] <= 'f')
1230 v
+= cfg
.proxy_telnet_command
[eo
] - 'a' + 10;
1231 else if (cfg
.proxy_telnet_command
[eo
] >= 'A' &&
1232 cfg
.proxy_telnet_command
[eo
] <= 'F')
1233 v
+= cfg
.proxy_telnet_command
[eo
] - 'A' + 10;
1235 /* non hex character, so we abort and just
1236 * send the whole thing unescaped (including \x)
1238 sk_write(p
->sub_socket
, "\\", 1);
1243 /* we only extract two hex characters */
1245 sk_write(p
->sub_socket
, &v
, 1);
1257 sk_write(p
->sub_socket
,
1258 cfg
.proxy_telnet_command
+ so
, 2);
1264 /* % escape. we recognize %%, %host, %port, %user, %pass.
1265 * anything else, we just send unescaped (including the %).
1268 if (cfg
.proxy_telnet_command
[eo
] == '%') {
1269 sk_write(p
->sub_socket
, "%", 1);
1272 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1275 sk_getaddr(p
->remote_addr
, dest
, lenof(dest
));
1276 sk_write(p
->sub_socket
, dest
, strlen(dest
));
1279 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1282 sprintf(port
, "%i", p
->remote_port
);
1283 sk_write(p
->sub_socket
, port
, strlen(port
));
1286 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1288 sk_write(p
->sub_socket
, cfg
.proxy_username
,
1289 strlen(cfg
.proxy_username
));
1292 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
1294 sk_write(p
->sub_socket
, cfg
.proxy_password
,
1295 strlen(cfg
.proxy_password
));
1299 /* we don't escape this, so send the % now, and
1300 * don't advance eo, so that we'll consider the
1301 * text immediately following the % as unescaped.
1303 sk_write(p
->sub_socket
, "%", 1);
1307 /* resume scanning for additional escapes after this one. */
1311 /* if there is any unescaped text at the end of the line, send it */
1313 sk_write(p
->sub_socket
, cfg
.proxy_telnet_command
+ so
, eo
- so
);
1320 if (change
== PROXY_CHANGE_CLOSING
) {
1321 /* if our proxy negotiation process involves closing and opening
1322 * new sockets, then we would want to intercept this closing
1323 * callback when we were expecting it. if we aren't anticipating
1324 * a socket close, then some error must have occurred. we'll
1325 * just pass those errors up to the backend.
1327 return plug_closing(p
->plug
, p
->closing_error_msg
,
1328 p
->closing_error_code
,
1329 p
->closing_calling_back
);
1332 if (change
== PROXY_CHANGE_SENT
) {
1333 /* some (or all) of what we wrote to the proxy was sent.
1334 * we don't do anything new, however, until we receive the
1335 * proxy's response. we might want to set a timer so we can
1336 * timeout the proxy negotiation after a while...
1341 if (change
== PROXY_CHANGE_ACCEPTING
) {
1342 /* we should _never_ see this, as we are using our socket to
1343 * connect to a proxy, not accepting inbound connections.
1344 * what should we do? close the socket with an appropriate
1347 return plug_accepting(p
->plug
, p
->accepting_sock
);
1350 if (change
== PROXY_CHANGE_RECEIVE
) {
1351 /* we have received data from the underlying socket, which
1352 * we'll need to parse, process, and respond to appropriately.
1357 /* proxy activate will have dealt with
1358 * whatever is left of the buffer */
1362 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1363 PROXY_ERROR_UNEXPECTED
, 0);