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(cfg) \
18 (cfg->proxy_dns == FORCE_ON || \
19 (cfg->proxy_dns == AUTO && cfg->proxy_type != PROXY_SOCKS4))
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
);
91 sk_addr_free(ps
->remote_addr
);
95 static int sk_proxy_write (Socket s
, const char *data
, int len
)
97 Proxy_Socket ps
= (Proxy_Socket
) s
;
99 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
100 bufchain_add(&ps
->pending_output_data
, data
, len
);
101 return bufchain_size(&ps
->pending_output_data
);
103 return sk_write(ps
->sub_socket
, data
, len
);
106 static int sk_proxy_write_oob (Socket s
, const char *data
, int len
)
108 Proxy_Socket ps
= (Proxy_Socket
) s
;
110 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
111 bufchain_clear(&ps
->pending_output_data
);
112 bufchain_clear(&ps
->pending_oob_output_data
);
113 bufchain_add(&ps
->pending_oob_output_data
, data
, len
);
116 return sk_write_oob(ps
->sub_socket
, data
, len
);
119 static void sk_proxy_flush (Socket s
)
121 Proxy_Socket ps
= (Proxy_Socket
) s
;
123 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
124 ps
->pending_flush
= 1;
127 sk_flush(ps
->sub_socket
);
130 static void sk_proxy_set_private_ptr (Socket s
, void *ptr
)
132 Proxy_Socket ps
= (Proxy_Socket
) s
;
133 sk_set_private_ptr(ps
->sub_socket
, ptr
);
136 static void * sk_proxy_get_private_ptr (Socket s
)
138 Proxy_Socket ps
= (Proxy_Socket
) s
;
139 return sk_get_private_ptr(ps
->sub_socket
);
142 static void sk_proxy_set_frozen (Socket s
, int is_frozen
)
144 Proxy_Socket ps
= (Proxy_Socket
) s
;
146 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
147 ps
->freeze
= is_frozen
;
151 /* handle any remaining buffered recv data first */
152 if (bufchain_size(&ps
->pending_input_data
) > 0) {
153 ps
->freeze
= is_frozen
;
155 /* loop while we still have buffered data, and while we are
156 * unfrozen. the plug_receive call in the loop could result
157 * in a call back into this function refreezing the socket,
158 * so we have to check each time.
160 while (!ps
->freeze
&& bufchain_size(&ps
->pending_input_data
) > 0) {
164 bufchain_prefix(&ps
->pending_input_data
, &data
, &len
);
165 if (len
> lenof(databuf
))
166 len
= lenof(databuf
);
167 memcpy(databuf
, data
, len
);
168 bufchain_consume(&ps
->pending_input_data
, len
);
169 plug_receive(ps
->plug
, 0, databuf
, len
);
172 /* if we're still frozen, we'll have to wait for another
173 * call from the backend to finish unbuffering the data.
175 if (ps
->freeze
) return;
178 sk_set_frozen(ps
->sub_socket
, is_frozen
);
181 static const char * sk_proxy_socket_error (Socket s
)
183 Proxy_Socket ps
= (Proxy_Socket
) s
;
184 if (ps
->error
!= NULL
|| ps
->sub_socket
== NULL
) {
187 return sk_socket_error(ps
->sub_socket
);
190 /* basic proxy plug functions */
192 static void plug_proxy_log(Plug plug
, int type
, SockAddr addr
, int port
,
193 const char *error_msg
, int error_code
)
195 Proxy_Plug pp
= (Proxy_Plug
) plug
;
196 Proxy_Socket ps
= pp
->proxy_socket
;
198 plug_log(ps
->plug
, type
, addr
, port
, error_msg
, error_code
);
201 static int plug_proxy_closing (Plug p
, const char *error_msg
,
202 int error_code
, int calling_back
)
204 Proxy_Plug pp
= (Proxy_Plug
) p
;
205 Proxy_Socket ps
= pp
->proxy_socket
;
207 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
208 ps
->closing_error_msg
= error_msg
;
209 ps
->closing_error_code
= error_code
;
210 ps
->closing_calling_back
= calling_back
;
211 return ps
->negotiate(ps
, PROXY_CHANGE_CLOSING
);
213 return plug_closing(ps
->plug
, error_msg
,
214 error_code
, calling_back
);
217 static int plug_proxy_receive (Plug p
, int urgent
, char *data
, int len
)
219 Proxy_Plug pp
= (Proxy_Plug
) p
;
220 Proxy_Socket ps
= pp
->proxy_socket
;
222 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
223 /* we will lose the urgentness of this data, but since most,
224 * if not all, of this data will be consumed by the negotiation
225 * process, hopefully it won't affect the protocol above us
227 bufchain_add(&ps
->pending_input_data
, data
, len
);
228 ps
->receive_urgent
= urgent
;
229 ps
->receive_data
= data
;
230 ps
->receive_len
= len
;
231 return ps
->negotiate(ps
, PROXY_CHANGE_RECEIVE
);
233 return plug_receive(ps
->plug
, urgent
, data
, len
);
236 static void plug_proxy_sent (Plug p
, int bufsize
)
238 Proxy_Plug pp
= (Proxy_Plug
) p
;
239 Proxy_Socket ps
= pp
->proxy_socket
;
241 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
242 ps
->sent_bufsize
= bufsize
;
243 ps
->negotiate(ps
, PROXY_CHANGE_SENT
);
246 plug_sent(ps
->plug
, bufsize
);
249 static int plug_proxy_accepting (Plug p
, OSSocket sock
)
251 Proxy_Plug pp
= (Proxy_Plug
) p
;
252 Proxy_Socket ps
= pp
->proxy_socket
;
254 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
255 ps
->accepting_sock
= sock
;
256 return ps
->negotiate(ps
, PROXY_CHANGE_ACCEPTING
);
258 return plug_accepting(ps
->plug
, sock
);
262 * This function can accept a NULL pointer as `addr', in which case
263 * it will only check the host name.
265 static int proxy_for_destination (SockAddr addr
, char *hostname
, int port
,
270 int hostip_len
, hostname_len
;
271 const char *exclude_list
;
274 * Check the host name and IP against the hard-coded
275 * representations of `localhost'.
277 if (!cfg
->even_proxy_localhost
&&
278 (sk_hostname_is_local(hostname
) ||
279 (addr
&& sk_address_is_local(addr
))))
280 return 0; /* do not proxy */
282 /* we want a string representation of the IP address for comparisons */
284 sk_getaddr(addr
, hostip
, 64);
285 hostip_len
= strlen(hostip
);
287 hostip_len
= 0; /* placate gcc; shouldn't be required */
289 hostname_len
= strlen(hostname
);
291 exclude_list
= cfg
->proxy_exclude_list
;
293 /* now parse the exclude list, and see if either our IP
294 * or hostname matches anything in it.
297 while (exclude_list
[s
]) {
298 while (exclude_list
[s
] &&
299 (isspace((unsigned char)exclude_list
[s
]) ||
300 exclude_list
[s
] == ',')) s
++;
302 if (!exclude_list
[s
]) break;
306 while (exclude_list
[e
] &&
307 (isalnum((unsigned char)exclude_list
[e
]) ||
308 exclude_list
[e
] == '-' ||
309 exclude_list
[e
] == '.' ||
310 exclude_list
[e
] == '*')) e
++;
312 if (exclude_list
[s
] == '*') {
313 /* wildcard at beginning of entry */
315 if ((addr
&& strnicmp(hostip
+ hostip_len
- (e
- s
- 1),
316 exclude_list
+ s
+ 1, e
- s
- 1) == 0) ||
317 strnicmp(hostname
+ hostname_len
- (e
- s
- 1),
318 exclude_list
+ s
+ 1, e
- s
- 1) == 0)
319 return 0; /* IP/hostname range excluded. do not use proxy. */
321 } else if (exclude_list
[e
-1] == '*') {
322 /* wildcard at end of entry */
324 if ((addr
&& strnicmp(hostip
, exclude_list
+ s
, e
- s
- 1) == 0) ||
325 strnicmp(hostname
, exclude_list
+ s
, e
- s
- 1) == 0)
326 return 0; /* IP/hostname range excluded. do not use proxy. */
329 /* no wildcard at either end, so let's try an absolute
330 * match (ie. a specific IP)
333 if (addr
&& strnicmp(hostip
, exclude_list
+ s
, e
- s
) == 0)
334 return 0; /* IP/hostname excluded. do not use proxy. */
335 if (strnicmp(hostname
, exclude_list
+ s
, e
- s
) == 0)
336 return 0; /* IP/hostname excluded. do not use proxy. */
341 /* Make sure we really have reached the next comma or end-of-string */
342 while (exclude_list
[s
] &&
343 !isspace((unsigned char)exclude_list
[s
]) &&
344 exclude_list
[s
] != ',') s
++;
347 /* no matches in the exclude list, so use the proxy */
351 SockAddr
name_lookup(char *host
, int port
, char **canonicalname
,
352 const Config
*cfg
, int addressfamily
)
354 if (cfg
->proxy_type
!= PROXY_NONE
&&
356 proxy_for_destination(NULL
, host
, port
, cfg
)) {
357 *canonicalname
= dupstr(host
);
358 return sk_nonamelookup(host
);
361 return sk_namelookup(host
, canonicalname
, addressfamily
);
364 Socket
new_connection(SockAddr addr
, char *hostname
,
365 int port
, int privport
,
366 int oobinline
, int nodelay
, int keepalive
,
367 Plug plug
, const Config
*cfg
)
369 static const struct socket_function_table socket_fn_table
= {
375 sk_proxy_set_private_ptr
,
376 sk_proxy_get_private_ptr
,
378 sk_proxy_socket_error
381 static const struct plug_function_table plug_fn_table
= {
389 if (cfg
->proxy_type
!= PROXY_NONE
&&
390 proxy_for_destination(addr
, hostname
, port
, cfg
))
395 char *proxy_canonical_name
;
398 if ((sret
= platform_new_connection(addr
, hostname
, port
, privport
,
399 oobinline
, nodelay
, keepalive
,
404 ret
= snew(struct Socket_proxy_tag
);
405 ret
->fn
= &socket_fn_table
;
406 ret
->cfg
= *cfg
; /* STRUCTURE COPY */
408 ret
->remote_addr
= addr
; /* will need to be freed on close */
409 ret
->remote_port
= port
;
412 ret
->pending_flush
= 0;
415 bufchain_init(&ret
->pending_input_data
);
416 bufchain_init(&ret
->pending_output_data
);
417 bufchain_init(&ret
->pending_oob_output_data
);
419 ret
->sub_socket
= NULL
;
420 ret
->state
= PROXY_STATE_NEW
;
421 ret
->negotiate
= NULL
;
423 if (cfg
->proxy_type
== PROXY_HTTP
) {
424 ret
->negotiate
= proxy_http_negotiate
;
425 } else if (cfg
->proxy_type
== PROXY_SOCKS4
) {
426 ret
->negotiate
= proxy_socks4_negotiate
;
427 } else if (cfg
->proxy_type
== PROXY_SOCKS5
) {
428 ret
->negotiate
= proxy_socks5_negotiate
;
429 } else if (cfg
->proxy_type
== PROXY_TELNET
) {
430 ret
->negotiate
= proxy_telnet_negotiate
;
432 ret
->error
= "Proxy error: Unknown proxy method";
436 /* create the proxy plug to map calls from the actual
437 * socket into our proxy socket layer */
438 pplug
= snew(struct Plug_proxy_tag
);
439 pplug
->fn
= &plug_fn_table
;
440 pplug
->proxy_socket
= ret
;
443 proxy_addr
= sk_namelookup(cfg
->proxy_host
,
444 &proxy_canonical_name
, cfg
->addressfamily
);
445 if (sk_addr_error(proxy_addr
) != NULL
) {
446 ret
->error
= "Proxy error: Unable to resolve proxy host name";
449 sfree(proxy_canonical_name
);
451 /* create the actual socket we will be using,
452 * connected to our proxy server and port.
454 ret
->sub_socket
= sk_new(proxy_addr
, cfg
->proxy_port
,
456 nodelay
, keepalive
, (Plug
) pplug
);
457 if (sk_socket_error(ret
->sub_socket
) != NULL
)
460 /* start the proxy negotiation process... */
461 sk_set_frozen(ret
->sub_socket
, 0);
462 ret
->negotiate(ret
, PROXY_CHANGE_NEW
);
467 /* no proxy, so just return the direct socket */
468 return sk_new(addr
, port
, privport
, oobinline
, nodelay
, keepalive
, plug
);
471 Socket
new_listener(char *srcaddr
, int port
, Plug plug
, int local_host_only
,
472 const Config
*cfg
, int addressfamily
)
474 /* TODO: SOCKS (and potentially others) support inbound
475 * TODO: connections via the proxy. support them.
478 return sk_newlistener(srcaddr
, port
, plug
, local_host_only
, addressfamily
);
481 /* ----------------------------------------------------------------------
482 * HTTP CONNECT proxy type.
485 static int get_line_end (char * data
, int len
)
491 if (data
[off
] == '\n') {
492 /* we have a newline */
495 /* is that the only thing on this line? */
496 if (off
<= 2) return off
;
498 /* if not, then there is the possibility that this header
499 * continues onto the next line, if it starts with a space
504 data
[off
+1] != ' ' &&
505 data
[off
+1] != '\t') return off
;
507 /* the line does continue, so we have to keep going
508 * until we see an the header's "real" end of line.
519 int proxy_http_negotiate (Proxy_Socket p
, int change
)
521 if (p
->state
== PROXY_STATE_NEW
) {
522 /* we are just beginning the proxy negotiate process,
523 * so we'll send off the initial bits of the request.
524 * for this proxy method, it's just a simple HTTP
527 char *buf
, dest
[512];
529 sk_getaddr(p
->remote_addr
, dest
, lenof(dest
));
531 buf
= dupprintf("CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n",
532 dest
, p
->remote_port
, dest
, p
->remote_port
);
533 sk_write(p
->sub_socket
, buf
, strlen(buf
));
536 if (p
->cfg
.proxy_username
[0] || p
->cfg
.proxy_password
[0]) {
537 char buf
[sizeof(p
->cfg
.proxy_username
)+sizeof(p
->cfg
.proxy_password
)];
538 char buf2
[sizeof(buf
)*4/3 + 100];
540 sprintf(buf
, "%s:%s", p
->cfg
.proxy_username
, p
->cfg
.proxy_password
);
542 sprintf(buf2
, "Proxy-Authorization: Basic ");
543 for (i
= 0, j
= strlen(buf2
); i
< len
; i
+= 3, j
+= 4)
544 base64_encode_atom((unsigned char *)(buf
+i
),
545 (len
-i
> 3 ?
3 : len
-i
), buf2
+j
);
546 strcpy(buf2
+j
, "\r\n");
547 sk_write(p
->sub_socket
, buf2
, strlen(buf2
));
550 sk_write(p
->sub_socket
, "\r\n", 2);
556 if (change
== PROXY_CHANGE_CLOSING
) {
557 /* if our proxy negotiation process involves closing and opening
558 * new sockets, then we would want to intercept this closing
559 * callback when we were expecting it. if we aren't anticipating
560 * a socket close, then some error must have occurred. we'll
561 * just pass those errors up to the backend.
563 return plug_closing(p
->plug
, p
->closing_error_msg
,
564 p
->closing_error_code
,
565 p
->closing_calling_back
);
568 if (change
== PROXY_CHANGE_SENT
) {
569 /* some (or all) of what we wrote to the proxy was sent.
570 * we don't do anything new, however, until we receive the
571 * proxy's response. we might want to set a timer so we can
572 * timeout the proxy negotiation after a while...
577 if (change
== PROXY_CHANGE_ACCEPTING
) {
578 /* we should _never_ see this, as we are using our socket to
579 * connect to a proxy, not accepting inbound connections.
580 * what should we do? close the socket with an appropriate
583 return plug_accepting(p
->plug
, p
->accepting_sock
);
586 if (change
== PROXY_CHANGE_RECEIVE
) {
587 /* we have received data from the underlying socket, which
588 * we'll need to parse, process, and respond to appropriately.
597 int min_ver
, maj_ver
, status
;
599 /* get the status line */
600 len
= bufchain_size(&p
->pending_input_data
);
601 assert(len
> 0); /* or we wouldn't be here */
602 data
= snewn(len
+1, char);
603 bufchain_fetch(&p
->pending_input_data
, data
, len
);
605 * We must NUL-terminate this data, because Windows
606 * sscanf appears to require a NUL at the end of the
607 * string because it strlens it _first_. Sigh.
611 eol
= get_line_end(data
, len
);
618 /* We can't rely on whether the %n incremented the sscanf return */
619 if (sscanf((char *)data
, "HTTP/%i.%i %n",
620 &maj_ver
, &min_ver
, &status
) < 2 || status
== -1) {
621 plug_closing(p
->plug
, "Proxy error: HTTP response was absent",
622 PROXY_ERROR_GENERAL
, 0);
627 /* remove the status line from the input buffer. */
628 bufchain_consume(&p
->pending_input_data
, eol
);
629 if (data
[status
] != '2') {
633 while (eol
> status
&&
634 (data
[eol
-1] == '\r' || data
[eol
-1] == '\n'))
636 buf
= dupprintf("Proxy error: %s", data
+status
);
637 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
650 /* get headers. we're done when we get a
651 * header of length 2, (ie. just "\r\n")
654 len
= bufchain_size(&p
->pending_input_data
);
655 assert(len
> 0); /* or we wouldn't be here */
656 data
= snewn(len
, char);
658 bufchain_fetch(&p
->pending_input_data
, data
, len
);
660 eol
= get_line_end(datap
, len
);
667 bufchain_consume(&p
->pending_input_data
, eol
);
670 eol
= get_line_end(datap
, len
);
675 bufchain_consume(&p
->pending_input_data
, 2);
677 /* proxy activate will have dealt with
678 * whatever is left of the buffer */
688 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
689 PROXY_ERROR_UNEXPECTED
, 0);
693 /* ----------------------------------------------------------------------
697 /* SOCKS version 4 */
698 int proxy_socks4_negotiate (Proxy_Socket p
, int change
)
700 if (p
->state
== PROXY_CHANGE_NEW
) {
703 * version number (1 byte) = 4
704 * command code (1 byte)
707 * dest. port (2 bytes) [network order]
708 * dest. address (4 bytes)
709 * user ID (variable length, null terminated string)
712 int length
, type
, namelen
;
713 char *command
, addr
[4], hostname
[512];
715 type
= sk_addrtype(p
->remote_addr
);
716 if (type
== ADDRTYPE_IPV6
) {
717 plug_closing(p
->plug
, "Proxy error: SOCKS version 4 does"
718 " not support IPv6", PROXY_ERROR_GENERAL
, 0);
720 } else if (type
== ADDRTYPE_IPV4
) {
722 sk_addrcopy(p
->remote_addr
, addr
);
723 } else { /* type == ADDRTYPE_NAME */
724 assert(type
== ADDRTYPE_NAME
);
725 sk_getaddr(p
->remote_addr
, hostname
, lenof(hostname
));
726 namelen
= strlen(hostname
) + 1; /* include the NUL */
727 addr
[0] = addr
[1] = addr
[2] = 0;
731 length
= strlen(p
->cfg
.proxy_username
) + namelen
+ 9;
732 command
= snewn(length
, char);
733 strcpy(command
+ 8, p
->cfg
.proxy_username
);
735 command
[0] = 4; /* version 4 */
736 command
[1] = 1; /* CONNECT command */
739 command
[2] = (char) (p
->remote_port
>> 8) & 0xff;
740 command
[3] = (char) p
->remote_port
& 0xff;
743 memcpy(command
+ 4, addr
, 4);
746 memcpy(command
+ 8 + strlen(p
->cfg
.proxy_username
) + 1,
749 sk_write(p
->sub_socket
, command
, length
);
756 if (change
== PROXY_CHANGE_CLOSING
) {
757 /* if our proxy negotiation process involves closing and opening
758 * new sockets, then we would want to intercept this closing
759 * callback when we were expecting it. if we aren't anticipating
760 * a socket close, then some error must have occurred. we'll
761 * just pass those errors up to the backend.
763 return plug_closing(p
->plug
, p
->closing_error_msg
,
764 p
->closing_error_code
,
765 p
->closing_calling_back
);
768 if (change
== PROXY_CHANGE_SENT
) {
769 /* some (or all) of what we wrote to the proxy was sent.
770 * we don't do anything new, however, until we receive the
771 * proxy's response. we might want to set a timer so we can
772 * timeout the proxy negotiation after a while...
777 if (change
== PROXY_CHANGE_ACCEPTING
) {
778 /* we should _never_ see this, as we are using our socket to
779 * connect to a proxy, not accepting inbound connections.
780 * what should we do? close the socket with an appropriate
783 return plug_accepting(p
->plug
, p
->accepting_sock
);
786 if (change
== PROXY_CHANGE_RECEIVE
) {
787 /* we have received data from the underlying socket, which
788 * we'll need to parse, process, and respond to appropriately.
793 * version number (1 byte) = 4
794 * reply code (1 byte)
795 * 90 = request granted
796 * 91 = request rejected or failed
797 * 92 = request rejected due to lack of IDENTD on client
798 * 93 = request rejected due to difference in user ID
799 * (what we sent vs. what IDENTD said)
800 * dest. port (2 bytes)
801 * dest. address (4 bytes)
806 if (bufchain_size(&p
->pending_input_data
) < 8)
807 return 1; /* not got anything yet */
809 /* get the response */
810 bufchain_fetch(&p
->pending_input_data
, data
, 8);
813 plug_closing(p
->plug
, "Proxy error: SOCKS proxy responded with "
814 "unexpected reply code version",
815 PROXY_ERROR_GENERAL
, 0);
823 plug_closing(p
->plug
, "Proxy error: SOCKS server wanted IDENTD on client",
824 PROXY_ERROR_GENERAL
, 0);
827 plug_closing(p
->plug
, "Proxy error: Username and IDENTD on client don't agree",
828 PROXY_ERROR_GENERAL
, 0);
832 plug_closing(p
->plug
, "Proxy error: Error while communicating with proxy",
833 PROXY_ERROR_GENERAL
, 0);
839 bufchain_consume(&p
->pending_input_data
, 8);
843 /* proxy activate will have dealt with
844 * whatever is left of the buffer */
849 plug_closing(p
->plug
, "Proxy error: unexpected proxy error",
850 PROXY_ERROR_UNEXPECTED
, 0);
854 /* SOCKS version 5 */
855 int proxy_socks5_negotiate (Proxy_Socket p
, int change
)
857 if (p
->state
== PROXY_CHANGE_NEW
) {
860 * version number (1 byte) = 5
861 * number of available authentication methods (1 byte)
862 * available authentication methods (1 byte * previous value)
863 * authentication methods:
864 * 0x00 = no authentication
866 * 0x02 = username/password
873 command
[0] = 5; /* version 5 */
874 if (p
->cfg
.proxy_username
[0] || p
->cfg
.proxy_password
[0]) {
875 command
[2] = 0x00; /* no authentication */
877 proxy_socks5_offerencryptedauth (command
, &len
);
878 command
[len
++] = 0x02; /* username/password */
879 command
[1] = len
- 2; /* Number of methods supported */
881 command
[1] = 1; /* one methods supported: */
882 command
[2] = 0x00; /* no authentication */
886 sk_write(p
->sub_socket
, command
, len
);
892 if (change
== PROXY_CHANGE_CLOSING
) {
893 /* if our proxy negotiation process involves closing and opening
894 * new sockets, then we would want to intercept this closing
895 * callback when we were expecting it. if we aren't anticipating
896 * a socket close, then some error must have occurred. we'll
897 * just pass those errors up to the backend.
899 return plug_closing(p
->plug
, p
->closing_error_msg
,
900 p
->closing_error_code
,
901 p
->closing_calling_back
);
904 if (change
== PROXY_CHANGE_SENT
) {
905 /* some (or all) of what we wrote to the proxy was sent.
906 * we don't do anything new, however, until we receive the
907 * proxy's response. we might want to set a timer so we can
908 * timeout the proxy negotiation after a while...
913 if (change
== PROXY_CHANGE_ACCEPTING
) {
914 /* we should _never_ see this, as we are using our socket to
915 * connect to a proxy, not accepting inbound connections.
916 * what should we do? close the socket with an appropriate
919 return plug_accepting(p
->plug
, p
->accepting_sock
);
922 if (change
== PROXY_CHANGE_RECEIVE
) {
923 /* we have received data from the underlying socket, which
924 * we'll need to parse, process, and respond to appropriately.
930 * version number (1 byte) = 5
931 * authentication method (1 byte)
932 * authentication methods:
933 * 0x00 = no authentication
935 * 0x02 = username/password
937 * 0xff = no acceptable methods
941 if (bufchain_size(&p
->pending_input_data
) < 2)
942 return 1; /* not got anything yet */
944 /* get the response */
945 bufchain_fetch(&p
->pending_input_data
, data
, 2);
948 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned unexpected version",
949 PROXY_ERROR_GENERAL
, 0);
953 if (data
[1] == 0x00) p
->state
= 2; /* no authentication needed */
954 else if (data
[1] == 0x01) p
->state
= 4; /* GSSAPI authentication */
955 else if (data
[1] == 0x02) p
->state
= 5; /* username/password authentication */
956 else if (data
[1] == 0x03) p
->state
= 6; /* CHAP authentication */
958 plug_closing(p
->plug
, "Proxy error: SOCKS proxy did not accept our authentication",
959 PROXY_ERROR_GENERAL
, 0);
962 bufchain_consume(&p
->pending_input_data
, 2);
967 /* password authentication reply format:
968 * version number (1 bytes) = 1
969 * reply code (1 byte)
975 if (bufchain_size(&p
->pending_input_data
) < 2)
976 return 1; /* not got anything yet */
978 /* get the response */
979 bufchain_fetch(&p
->pending_input_data
, data
, 2);
982 plug_closing(p
->plug
, "Proxy error: SOCKS password "
983 "subnegotiation contained wrong version number",
984 PROXY_ERROR_GENERAL
, 0);
990 plug_closing(p
->plug
, "Proxy error: SOCKS proxy refused"
991 " password authentication",
992 PROXY_ERROR_GENERAL
, 0);
996 bufchain_consume(&p
->pending_input_data
, 2);
997 p
->state
= 2; /* now proceed as authenticated */
1000 if (p
->state
== 8) {
1002 ret
= proxy_socks5_handlechap(p
);
1003 if (ret
) return ret
;
1006 if (p
->state
== 2) {
1009 * version number (1 byte) = 5
1010 * command code (1 byte)
1014 * reserved (1 byte) = 0x00
1015 * address type (1 byte)
1017 * 3 = domainname (first byte has length, no terminating null)
1019 * dest. address (variable)
1020 * dest. port (2 bytes) [network order]
1027 type
= sk_addrtype(p
->remote_addr
);
1028 if (type
== ADDRTYPE_IPV4
) {
1029 len
= 10; /* 4 hdr + 4 addr + 2 trailer */
1030 command
[3] = 1; /* IPv4 */
1031 sk_addrcopy(p
->remote_addr
, command
+4);
1032 } else if (type
== ADDRTYPE_IPV6
) {
1033 len
= 22; /* 4 hdr + 16 addr + 2 trailer */
1034 command
[3] = 4; /* IPv6 */
1035 sk_addrcopy(p
->remote_addr
, command
+4);
1037 assert(type
== ADDRTYPE_NAME
);
1039 sk_getaddr(p
->remote_addr
, command
+5, 256);
1040 command
[4] = strlen(command
+5);
1041 len
= 7 + command
[4]; /* 4 hdr, 1 len, N addr, 2 trailer */
1044 command
[0] = 5; /* version 5 */
1045 command
[1] = 1; /* CONNECT command */
1049 command
[len
-2] = (char) (p
->remote_port
>> 8) & 0xff;
1050 command
[len
-1] = (char) p
->remote_port
& 0xff;
1052 sk_write(p
->sub_socket
, command
, len
);
1058 if (p
->state
== 3) {
1061 * version number (1 bytes) = 5
1062 * reply code (1 byte)
1064 * 1 = general SOCKS server failure
1065 * 2 = connection not allowed by ruleset
1066 * 3 = network unreachable
1067 * 4 = host unreachable
1068 * 5 = connection refused
1070 * 7 = command not supported
1071 * 8 = address type not supported
1072 * reserved (1 byte) = x00
1073 * address type (1 byte)
1075 * 3 = domainname (first byte has length, no terminating null)
1077 * server bound address (variable)
1078 * server bound port (2 bytes) [network order]
1083 /* First 5 bytes of packet are enough to tell its length. */
1084 if (bufchain_size(&p
->pending_input_data
) < 5)
1085 return 1; /* not got anything yet */
1087 /* get the response */
1088 bufchain_fetch(&p
->pending_input_data
, data
, 5);
1091 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned wrong version number",
1092 PROXY_ERROR_GENERAL
, 0);
1099 strcpy(buf
, "Proxy error: ");
1102 case 1: strcat(buf
, "General SOCKS server failure"); break;
1103 case 2: strcat(buf
, "Connection not allowed by ruleset"); break;
1104 case 3: strcat(buf
, "Network unreachable"); break;
1105 case 4: strcat(buf
, "Host unreachable"); break;
1106 case 5: strcat(buf
, "Connection refused"); break;
1107 case 6: strcat(buf
, "TTL expired"); break;
1108 case 7: strcat(buf
, "Command not supported"); break;
1109 case 8: strcat(buf
, "Address type not supported"); break;
1110 default: sprintf(buf
+strlen(buf
),
1111 "Unrecognised SOCKS error code %d",
1115 plug_closing(p
->plug
, buf
, PROXY_ERROR_GENERAL
, 0);
1121 * Eat the rest of the reply packet.
1123 len
= 6; /* first 4 bytes, last 2 */
1125 case 1: len
+= 4; break; /* IPv4 address */
1126 case 4: len
+= 16; break;/* IPv6 address */
1127 case 3: len
+= (unsigned char)data
[4]; break; /* domain name */
1129 plug_closing(p
->plug
, "Proxy error: SOCKS proxy returned "
1130 "unrecognised address format",
1131 PROXY_ERROR_GENERAL
, 0);
1134 if (bufchain_size(&p
->pending_input_data
) < len
)
1135 return 1; /* not got whole reply yet */
1136 bufchain_consume(&p
->pending_input_data
, len
);
1143 if (p
->state
== 4) {
1144 /* TODO: Handle GSSAPI authentication */
1145 plug_closing(p
->plug
, "Proxy error: We don't support GSSAPI authentication",
1146 PROXY_ERROR_GENERAL
, 0);
1150 if (p
->state
== 5) {
1151 if (p
->cfg
.proxy_username
[0] || p
->cfg
.proxy_password
[0]) {
1152 char userpwbuf
[514];
1154 ulen
= strlen(p
->cfg
.proxy_username
);
1155 if (ulen
> 255) ulen
= 255; if (ulen
< 1) ulen
= 1;
1156 plen
= strlen(p
->cfg
.proxy_password
);
1157 if (plen
> 255) plen
= 255; if (plen
< 1) plen
= 1;
1158 userpwbuf
[0] = 1; /* version number of subnegotiation */
1159 userpwbuf
[1] = ulen
;
1160 memcpy(userpwbuf
+2, p
->cfg
.proxy_username
, ulen
);
1161 userpwbuf
[ulen
+2] = plen
;
1162 memcpy(userpwbuf
+ulen
+3, p
->cfg
.proxy_password
, plen
);
1163 sk_write(p
->sub_socket
, userpwbuf
, ulen
+ plen
+ 3);
1166 plug_closing(p
->plug
, "Proxy error: Server chose "
1167 "username/password authentication but we "
1169 PROXY_ERROR_GENERAL
, 0);
1173 if (p
->state
== 6) {
1175 ret
= proxy_socks5_selectchap(p
);
1176 if (ret
) return ret
;
1181 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1182 PROXY_ERROR_UNEXPECTED
, 0);
1186 /* ----------------------------------------------------------------------
1187 * `Telnet' proxy type.
1189 * (This is for ad-hoc proxies where you connect to the proxy's
1190 * telnet port and send a command such as `connect host port'. The
1191 * command is configurable, since this proxy type is typically not
1192 * standardised or at all well-defined.)
1195 char *format_telnet_command(SockAddr addr
, int port
, const Config
*cfg
)
1198 int retlen
= 0, retsize
= 0;
1200 #define ENSURE(n) do { \
1201 if (retsize < retlen + n) { \
1202 retsize = retlen + n + 512; \
1203 ret = sresize(ret, retsize, char); \
1207 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
1208 * %%, %host, %port, %user, and %pass
1211 while (cfg
->proxy_telnet_command
[eo
] != 0) {
1213 /* scan forward until we hit end-of-line,
1214 * or an escape character (\ or %) */
1215 while (cfg
->proxy_telnet_command
[eo
] != 0 &&
1216 cfg
->proxy_telnet_command
[eo
] != '%' &&
1217 cfg
->proxy_telnet_command
[eo
] != '\\') eo
++;
1219 /* if we hit eol, break out of our escaping loop */
1220 if (cfg
->proxy_telnet_command
[eo
] == 0) break;
1222 /* if there was any unescaped text before the escape
1223 * character, send that now */
1226 memcpy(ret
+ retlen
, cfg
->proxy_telnet_command
+ so
, eo
- so
);
1232 /* if the escape character was the last character of
1233 * the line, we'll just stop and send it. */
1234 if (cfg
->proxy_telnet_command
[eo
] == 0) break;
1236 if (cfg
->proxy_telnet_command
[so
] == '\\') {
1238 /* we recognize \\, \%, \r, \n, \t, \x??.
1239 * anything else, we just send unescaped (including the \).
1242 switch (cfg
->proxy_telnet_command
[eo
]) {
1246 ret
[retlen
++] = '\\';
1252 ret
[retlen
++] = '%';
1258 ret
[retlen
++] = '\r';
1264 ret
[retlen
++] = '\n';
1270 ret
[retlen
++] = '\t';
1277 /* escaped hexadecimal value (ie. \xff) */
1278 unsigned char v
= 0;
1283 if (cfg
->proxy_telnet_command
[eo
] >= '0' &&
1284 cfg
->proxy_telnet_command
[eo
] <= '9')
1285 v
+= cfg
->proxy_telnet_command
[eo
] - '0';
1286 else if (cfg
->proxy_telnet_command
[eo
] >= 'a' &&
1287 cfg
->proxy_telnet_command
[eo
] <= 'f')
1288 v
+= cfg
->proxy_telnet_command
[eo
] - 'a' + 10;
1289 else if (cfg
->proxy_telnet_command
[eo
] >= 'A' &&
1290 cfg
->proxy_telnet_command
[eo
] <= 'F')
1291 v
+= cfg
->proxy_telnet_command
[eo
] - 'A' + 10;
1293 /* non hex character, so we abort and just
1294 * send the whole thing unescaped (including \x)
1297 ret
[retlen
++] = '\\';
1302 /* we only extract two hex characters */
1318 memcpy(ret
+retlen
, cfg
->proxy_telnet_command
+ so
, 2);
1325 /* % escape. we recognize %%, %host, %port, %user, %pass.
1326 * %proxyhost, %proxyport. Anything else we just send
1327 * unescaped (including the %).
1330 if (cfg
->proxy_telnet_command
[eo
] == '%') {
1332 ret
[retlen
++] = '%';
1335 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1339 sk_getaddr(addr
, dest
, lenof(dest
));
1340 destlen
= strlen(dest
);
1342 memcpy(ret
+retlen
, dest
, destlen
);
1346 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1348 char portstr
[8], portlen
;
1349 portlen
= sprintf(portstr
, "%i", port
);
1351 memcpy(ret
+ retlen
, portstr
, portlen
);
1355 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1357 int userlen
= strlen(cfg
->proxy_username
);
1359 memcpy(ret
+retlen
, cfg
->proxy_username
, userlen
);
1363 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1365 int passlen
= strlen(cfg
->proxy_password
);
1367 memcpy(ret
+retlen
, cfg
->proxy_password
, passlen
);
1371 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1372 "proxyhost", 9) == 0) {
1373 int phlen
= strlen(cfg
->proxy_host
);
1375 memcpy(ret
+retlen
, cfg
->proxy_host
, phlen
);
1379 else if (strnicmp(cfg
->proxy_telnet_command
+ eo
,
1380 "proxyport", 9) == 0) {
1383 sprintf(pport
, "%d", cfg
->proxy_port
);
1384 pplen
= strlen(pport
);
1386 memcpy(ret
+retlen
, pport
, pplen
);
1391 /* we don't escape this, so send the % now, and
1392 * don't advance eo, so that we'll consider the
1393 * text immediately following the % as unescaped.
1396 ret
[retlen
++] = '%';
1400 /* resume scanning for additional escapes after this one. */
1404 /* if there is any unescaped text at the end of the line, send it */
1407 memcpy(ret
+ retlen
, cfg
->proxy_telnet_command
+ so
, eo
- so
);
1418 int proxy_telnet_negotiate (Proxy_Socket p
, int change
)
1420 if (p
->state
== PROXY_CHANGE_NEW
) {
1421 char *formatted_cmd
;
1423 formatted_cmd
= format_telnet_command(p
->remote_addr
, p
->remote_port
,
1426 sk_write(p
->sub_socket
, formatted_cmd
, strlen(formatted_cmd
));
1427 sfree(formatted_cmd
);
1433 if (change
== PROXY_CHANGE_CLOSING
) {
1434 /* if our proxy negotiation process involves closing and opening
1435 * new sockets, then we would want to intercept this closing
1436 * callback when we were expecting it. if we aren't anticipating
1437 * a socket close, then some error must have occurred. we'll
1438 * just pass those errors up to the backend.
1440 return plug_closing(p
->plug
, p
->closing_error_msg
,
1441 p
->closing_error_code
,
1442 p
->closing_calling_back
);
1445 if (change
== PROXY_CHANGE_SENT
) {
1446 /* some (or all) of what we wrote to the proxy was sent.
1447 * we don't do anything new, however, until we receive the
1448 * proxy's response. we might want to set a timer so we can
1449 * timeout the proxy negotiation after a while...
1454 if (change
== PROXY_CHANGE_ACCEPTING
) {
1455 /* we should _never_ see this, as we are using our socket to
1456 * connect to a proxy, not accepting inbound connections.
1457 * what should we do? close the socket with an appropriate
1460 return plug_accepting(p
->plug
, p
->accepting_sock
);
1463 if (change
== PROXY_CHANGE_RECEIVE
) {
1464 /* we have received data from the underlying socket, which
1465 * we'll need to parse, process, and respond to appropriately.
1470 /* proxy activate will have dealt with
1471 * whatever is left of the buffer */
1475 plug_closing(p
->plug
, "Proxy error: Unexpected proxy error",
1476 PROXY_ERROR_UNEXPECTED
, 0);