2 * Network proxy abstraction in PuTTY
4 * A proxy layer, if necessary, wedges itself between the network
5 * code and the higher level backend.
10 #define DEFINE_PLUG_METHOD_MACROS
16 * Call this when proxy negotiation is complete, so that this
17 * socket can begin working normally.
19 void proxy_activate (Proxy_Socket p
)
24 p
->state
= PROXY_STATE_ACTIVE
;
26 /* let's try to keep extra receive events from coming through */
27 sk_set_frozen(p
->sub_socket
, 1);
29 /* send buffered OOB writes */
30 while (bufchain_size(&p
->pending_oob_output_data
) > 0) {
31 bufchain_prefix(&p
->pending_oob_output_data
, &data
, &len
);
32 sk_write_oob(p
->sub_socket
, data
, len
);
33 bufchain_consume(&p
->pending_oob_output_data
, len
);
35 bufchain_clear(&p
->pending_oob_output_data
);
37 /* send buffered normal writes */
38 while (bufchain_size(&p
->pending_output_data
) > 0) {
39 bufchain_prefix(&p
->pending_output_data
, &data
, &len
);
40 sk_write(p
->sub_socket
, data
, len
);
41 bufchain_consume(&p
->pending_output_data
, len
);
43 bufchain_clear(&p
->pending_output_data
);
45 /* if we were asked to flush the output during
46 * the proxy negotiation process, do so now.
48 if (p
->pending_flush
) sk_flush(p
->sub_socket
);
50 /* forward buffered recv data to the backend */
51 while (bufchain_size(&p
->pending_input_data
) > 0) {
52 bufchain_prefix(&p
->pending_input_data
, &data
, &len
);
53 plug_receive(p
->plug
, 0, data
, len
);
54 bufchain_consume(&p
->pending_input_data
, len
);
56 bufchain_clear(&p
->pending_input_data
);
58 /* now set the underlying socket to whatever freeze state they wanted */
59 sk_set_frozen(p
->sub_socket
, p
->freeze
);
62 /* basic proxy socket functions */
64 static Plug
sk_proxy_plug (Socket s
, Plug p
)
66 Proxy_Socket ps
= (Proxy_Socket
) s
;
73 static void sk_proxy_close (Socket s
)
75 Proxy_Socket ps
= (Proxy_Socket
) s
;
77 sk_close(ps
->sub_socket
);
81 static int sk_proxy_write (Socket s
, char *data
, int len
)
83 Proxy_Socket ps
= (Proxy_Socket
) s
;
85 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
86 bufchain_add(&ps
->pending_output_data
, data
, len
);
87 return bufchain_size(&ps
->pending_output_data
);
89 return sk_write(ps
->sub_socket
, data
, len
);
92 static int sk_proxy_write_oob (Socket s
, char *data
, int len
)
94 Proxy_Socket ps
= (Proxy_Socket
) s
;
96 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
97 bufchain_clear(&ps
->pending_output_data
);
98 bufchain_clear(&ps
->pending_oob_output_data
);
99 bufchain_add(&ps
->pending_oob_output_data
, data
, len
);
102 return sk_write_oob(ps
->sub_socket
, data
, len
);
105 static void sk_proxy_flush (Socket s
)
107 Proxy_Socket ps
= (Proxy_Socket
) s
;
109 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
110 ps
->pending_flush
= 1;
113 sk_flush(ps
->sub_socket
);
116 static void sk_proxy_set_private_ptr (Socket s
, void *ptr
)
118 Proxy_Socket ps
= (Proxy_Socket
) s
;
119 sk_set_private_ptr(ps
->sub_socket
, ptr
);
122 static void * sk_proxy_get_private_ptr (Socket s
)
124 Proxy_Socket ps
= (Proxy_Socket
) s
;
125 return sk_get_private_ptr(ps
->sub_socket
);
128 static void sk_proxy_set_frozen (Socket s
, int is_frozen
)
130 Proxy_Socket ps
= (Proxy_Socket
) s
;
132 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
133 ps
->freeze
= is_frozen
;
136 sk_set_frozen(ps
->sub_socket
, is_frozen
);
139 static char * sk_proxy_socket_error (Socket s
)
141 Proxy_Socket ps
= (Proxy_Socket
) s
;
142 if (ps
->error
!= NULL
|| ps
->sub_socket
== NULL
) {
145 return sk_socket_error(ps
->sub_socket
);
148 /* basic proxy plug functions */
150 static int plug_proxy_closing (Plug p
, char *error_msg
,
151 int error_code
, int calling_back
)
153 Proxy_Plug pp
= (Proxy_Plug
) p
;
154 Proxy_Socket ps
= pp
->proxy_socket
;
156 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
157 ps
->closing_error_msg
= error_msg
;
158 ps
->closing_error_code
= error_code
;
159 ps
->closing_calling_back
= calling_back
;
160 return ps
->negotiate(ps
, PROXY_CHANGE_CLOSING
);
162 return plug_closing(ps
->plug
, error_msg
,
163 error_code
, calling_back
);
166 static int plug_proxy_receive (Plug p
, int urgent
, char *data
, int len
)
168 Proxy_Plug pp
= (Proxy_Plug
) p
;
169 Proxy_Socket ps
= pp
->proxy_socket
;
171 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
172 /* we will lose the urgentness of this data, but since most,
173 * if not all, of this data will be consumed by the negotiation
174 * process, hopefully it won't affect the protocol above us
176 bufchain_add(&ps
->pending_input_data
, data
, len
);
177 ps
->receive_urgent
= urgent
;
178 ps
->receive_data
= data
;
179 ps
->receive_len
= len
;
180 return ps
->negotiate(ps
, PROXY_CHANGE_RECEIVE
);
182 return plug_receive(ps
->plug
, urgent
, data
, len
);
185 static void plug_proxy_sent (Plug p
, int bufsize
)
187 Proxy_Plug pp
= (Proxy_Plug
) p
;
188 Proxy_Socket ps
= pp
->proxy_socket
;
190 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
191 ps
->sent_bufsize
= bufsize
;
192 ps
->negotiate(ps
, PROXY_CHANGE_SENT
);
195 plug_sent(ps
->plug
, bufsize
);
198 static int plug_proxy_accepting (Plug p
, void *sock
)
200 Proxy_Plug pp
= (Proxy_Plug
) p
;
201 Proxy_Socket ps
= pp
->proxy_socket
;
203 if (ps
->state
!= PROXY_STATE_ACTIVE
) {
204 ps
->accepting_sock
= sock
;
205 return ps
->negotiate(ps
, PROXY_CHANGE_ACCEPTING
);
207 return plug_accepting(ps
->plug
, sock
);
210 static int proxy_for_destination (SockAddr addr
, char * hostname
, int port
)
214 int hostip_len
, hostname_len
;
217 /* we want a string representation of the IP address for comparisons */
218 sk_getaddr(addr
, hostip
, 64);
220 hostip_len
= strlen(hostip
);
221 hostname_len
= strlen(hostname
);
223 exclude_list
= cfg
.proxy_exclude_list
;
225 /* now parse the exclude list, and see if either our IP
226 * or hostname matches anything in it.
229 while (exclude_list
[s
]) {
230 while (exclude_list
[s
] &&
231 (isspace(exclude_list
[s
]) ||
232 exclude_list
[s
] == ',')) s
++;
234 if (!exclude_list
[s
]) break;
238 while (exclude_list
[e
] &&
239 (isalnum(exclude_list
[e
]) ||
240 exclude_list
[e
] == '-' ||
241 exclude_list
[e
] == '.' ||
242 exclude_list
[e
] == '*')) e
++;
244 if (exclude_list
[s
] == '*') {
245 /* wildcard at beginning of entry */
247 if (strnicmp(hostip
+ hostip_len
- (e
- s
- 1),
248 exclude_list
+ s
+ 1, e
- s
- 1) == 0 ||
249 strnicmp(hostname
+ hostname_len
- (e
- s
- 1),
250 exclude_list
+ s
+ 1, e
- s
- 1) == 0)
251 return 0; /* IP/hostname range excluded. do not use proxy. */
253 } else if (exclude_list
[e
-1] == '*') {
254 /* wildcard at end of entry */
256 if (strnicmp(hostip
, exclude_list
+ s
, e
- s
- 1) == 0 ||
257 strnicmp(hostname
, exclude_list
+ s
, e
- s
- 1) == 0)
258 return 0; /* IP/hostname range excluded. do not use proxy. */
261 /* no wildcard at either end, so let's try an absolute
262 * match (ie. a specific IP)
265 if (stricmp(hostip
, exclude_list
+ s
) == 0)
266 return 0; /* IP/hostname excluded. do not use proxy. */
267 if (stricmp(hostname
, exclude_list
+ s
) == 0)
268 return 0; /* IP/hostname excluded. do not use proxy. */
274 /* no matches in the exclude list, so use the proxy */
278 Socket
new_connection(SockAddr addr
, char *hostname
,
279 int port
, int privport
,
280 int oobinline
, int nodelay
, Plug plug
)
282 static struct socket_function_table socket_fn_table
= {
288 sk_proxy_set_private_ptr
,
289 sk_proxy_get_private_ptr
,
291 sk_proxy_socket_error
294 static struct plug_function_table plug_fn_table
= {
301 if (cfg
.proxy_type
!= PROXY_NONE
&&
302 proxy_for_destination(addr
, hostname
, port
))
307 char * proxy_canonical_name
;
309 ret
= smalloc(sizeof(struct Socket_proxy_tag
));
310 ret
->fn
= &socket_fn_table
;
312 ret
->remote_addr
= addr
;
313 ret
->remote_port
= port
;
315 bufchain_init(&ret
->pending_input_data
);
316 bufchain_init(&ret
->pending_output_data
);
317 bufchain_init(&ret
->pending_oob_output_data
);
319 ret
->sub_socket
= NULL
;
320 ret
->state
= PROXY_STATE_NEW
;
322 if (cfg
.proxy_type
== PROXY_HTTP
) {
323 ret
->negotiate
= proxy_http_negotiate
;
324 } else if (cfg
.proxy_type
== PROXY_SOCKS
) {
325 ret
->negotiate
= proxy_socks_negotiate
;
326 } else if (cfg
.proxy_type
== PROXY_TELNET
) {
327 ret
->negotiate
= proxy_telnet_negotiate
;
329 ret
->error
= "Network error: Unknown proxy method";
333 /* create the proxy plug to map calls from the actual
334 * socket into our proxy socket layer */
335 pplug
= smalloc(sizeof(struct Plug_proxy_tag
));
336 pplug
->fn
= &plug_fn_table
;
337 pplug
->proxy_socket
= ret
;
340 proxy_addr
= sk_namelookup(cfg
.proxy_host
,
341 &proxy_canonical_name
);
342 sfree(proxy_canonical_name
);
344 /* create the actual socket we will be using,
345 * connected to our proxy server and port.
347 ret
->sub_socket
= sk_new(proxy_addr
, cfg
.proxy_port
,
349 nodelay
, (Plug
) pplug
);
350 if (sk_socket_error(ret
->sub_socket
) != NULL
)
353 sk_addr_free(proxy_addr
);
355 /* start the proxy negotiation process... */
356 sk_set_frozen(ret
->sub_socket
, 0);
357 ret
->negotiate(ret
, PROXY_CHANGE_NEW
);
362 /* no proxy, so just return the direct socket */
363 return sk_new(addr
, port
, privport
, oobinline
, nodelay
, plug
);
366 Socket
new_listener(int port
, Plug plug
, int local_host_only
)
368 /* TODO: SOCKS (and potentially others) support inbound
369 * TODO: connections via the proxy. support them.
372 return sk_newlistener(port
, plug
, local_host_only
);
375 /* ----------------------------------------------------------------------
376 * HTTP CONNECT proxy type.
379 static int get_line_end (char * data
, int len
)
385 if (data
[off
] == '\n') {
386 /* we have a newline */
389 /* is that the only thing on this line? */
390 if (off
<= 2) return off
;
392 /* if not, then there is the possibility that this header
393 * continues onto the next line, if it starts with a space
398 data
[off
+1] != ' ' &&
399 data
[off
+1] != '\t') return off
;
401 /* the line does continue, so we have to keep going
402 * until we see an the header's "real" end of line.
413 int proxy_http_negotiate (Proxy_Socket p
, int change
)
415 if (p
->state
== PROXY_STATE_NEW
) {
416 /* we are just beginning the proxy negotiate process,
417 * so we'll send off the initial bits of the request.
418 * for this proxy method, it's just a simple HTTP
421 char buf
[256], dest
[64];
423 sk_getaddr(p
->remote_addr
, dest
, 64);
425 sprintf(buf
, "CONNECT %s:%i HTTP/1.1\r\nHost: %s:%i\r\n\r\n",
426 dest
, p
->remote_port
, dest
, p
->remote_port
);
427 sk_write(p
->sub_socket
, buf
, strlen(buf
));
434 if (change
== PROXY_CHANGE_CLOSING
) {
435 /* if our proxy negotiation process involves closing and opening
436 * new sockets, then we would want to intercept this closing
437 * callback when we were expecting it. if we aren't anticipating
438 * a socket close, then some error must have occurred. we'll
439 * just pass those errors up to the backend.
441 return plug_closing(p
->plug
, p
->closing_error_msg
,
442 p
->closing_error_code
,
443 p
->closing_calling_back
);
446 if (change
== PROXY_CHANGE_SENT
) {
447 /* some (or all) of what we wrote to the proxy was sent.
448 * we don't do anything new, however, until we receive the
449 * proxy's response. we might want to set a timer so we can
450 * timeout the proxy negotiation after a while...
455 if (change
== PROXY_CHANGE_ACCEPTING
) {
456 /* we should _never_ see this, as we are using our socket to
457 * connect to a proxy, not accepting inbound connections.
458 * what should we do? close the socket with an appropriate
461 return plug_accepting(p
->plug
, p
->accepting_sock
);
464 if (change
== PROXY_CHANGE_RECEIVE
) {
465 /* we have received data from the underlying socket, which
466 * we'll need to parse, process, and respond to appropriately.
475 int min_ver
, maj_ver
, status
;
477 /* get the status line */
478 bufchain_prefix(&p
->pending_input_data
, &data
, &len
);
479 eol
= get_line_end(data
, len
);
480 if (eol
< 0) return 1;
482 sscanf((char *)data
, "HTTP/%i.%i %i", &maj_ver
, &min_ver
, &status
);
484 /* remove the status line from the input buffer. */
485 bufchain_consume(&p
->pending_input_data
, eol
);
487 /* TODO: we need to support Proxy-Auth headers */
489 if (status
< 200 || status
> 299) {
491 /* TODO: return a more specific error message,
492 * TODO: based on the status code.
494 plug_closing(p
->plug
, "Network error: Error while communicating with proxy",
495 PROXY_ERROR_GENERAL
, 0);
504 /* get headers. we're done when we get a
505 * header of length 2, (ie. just "\r\n")
508 bufchain_prefix(&p
->pending_input_data
, &data
, &len
);
509 eol
= get_line_end(data
, len
);
512 /* TODO: Proxy-Auth stuff. in some cases, we will
513 * TODO: need to extract information from headers.
515 bufchain_consume(&p
->pending_input_data
, eol
);
516 bufchain_prefix(&p
->pending_input_data
, &data
, &len
);
517 eol
= get_line_end(data
, len
);
522 bufchain_consume(&p
->pending_input_data
, 2);
524 /* proxy activate will have dealt with
525 * whatever is left of the buffer */
533 plug_closing(p
->plug
, "Network error: Unexpected proxy error",
534 PROXY_ERROR_UNEXPECTED
, 0);
538 /* ----------------------------------------------------------------------
539 * SOCKS proxy type (as yet unimplemented).
542 int proxy_socks_negotiate (Proxy_Socket p
, int change
)
544 p
->error
= "Network error: SOCKS proxy implementation is incomplete";
548 /* ----------------------------------------------------------------------
549 * `Telnet' proxy type.
551 * (This is for ad-hoc proxies where you connect to the proxy's
552 * telnet port and send a command such as `connect host port'. The
553 * command is configurable, since this proxy type is typically not
554 * standardised or at all well-defined.)
557 int proxy_telnet_negotiate (Proxy_Socket p
, int change
)
559 if (p
->state
== PROXY_CHANGE_NEW
) {
563 /* we need to escape \\, \%, \r, \n, \t, \x??, \0???,
564 * %%, %host, and %port
567 while (cfg
.proxy_telnet_command
[eo
] != 0) {
569 /* scan forward until we hit end-of-line,
570 * or an escape character (\ or %) */
571 while (cfg
.proxy_telnet_command
[eo
] != 0 &&
572 cfg
.proxy_telnet_command
[eo
] != '%' &&
573 cfg
.proxy_telnet_command
[eo
] != '\\') eo
++;
575 /* if we hit eol, break out of our escaping loop */
576 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
578 /* if there was any unescaped text before the escape
579 * character, send that now */
581 sk_write(p
->sub_socket
,
582 cfg
.proxy_telnet_command
+ so
, eo
- so
);
587 /* if the escape character was the last character of
588 * the line, we'll just stop and send it. */
589 if (cfg
.proxy_telnet_command
[eo
] == 0) break;
591 if (cfg
.proxy_telnet_command
[so
] == '\\') {
593 /* we recognize \\, \%, \r, \n, \t, \x??.
594 * anything else, we just send unescaped (including the \).
597 switch (cfg
.proxy_telnet_command
[eo
]) {
600 sk_write(p
->sub_socket
, "\\", 1);
605 sk_write(p
->sub_socket
, "%%", 1);
610 sk_write(p
->sub_socket
, "\r", 1);
615 sk_write(p
->sub_socket
, "\n", 1);
620 sk_write(p
->sub_socket
, "\t", 1);
627 /* escaped hexadecimal value (ie. \xff) */
633 if (cfg
.proxy_telnet_command
[eo
] >= '0' &&
634 cfg
.proxy_telnet_command
[eo
] <= '9')
635 v
+= cfg
.proxy_telnet_command
[eo
] - '0';
636 else if (cfg
.proxy_telnet_command
[eo
] >= 'a' &&
637 cfg
.proxy_telnet_command
[eo
] <= 'f')
638 v
+= cfg
.proxy_telnet_command
[eo
] - 'a' + 10;
639 else if (cfg
.proxy_telnet_command
[eo
] >= 'A' &&
640 cfg
.proxy_telnet_command
[eo
] <= 'F')
641 v
+= cfg
.proxy_telnet_command
[eo
] - 'A' + 10;
643 /* non hex character, so we abort and just
644 * send the whole thing unescaped (including \x)
646 sk_write(p
->sub_socket
, "\\", 1);
651 /* we only extract two hex characters */
653 sk_write(p
->sub_socket
, &v
, 1);
665 sk_write(p
->sub_socket
,
666 cfg
.proxy_telnet_command
+ so
, 2);
672 /* % escape. we recognize %%, %host, %port. anything else,
673 * we just send unescaped (including the %). */
675 if (cfg
.proxy_telnet_command
[eo
] == '%') {
676 sk_write(p
->sub_socket
, "%", 1);
679 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
682 sk_getaddr(p
->remote_addr
, dest
, 64);
683 sk_write(p
->sub_socket
, dest
, strlen(dest
));
686 else if (strnicmp(cfg
.proxy_telnet_command
+ eo
,
689 sprintf(port
, "%i", p
->remote_port
);
690 sk_write(p
->sub_socket
, port
, strlen(port
));
694 /* we don't escape this, so send the % now, and
695 * don't advance eo, so that we'll consider the
696 * text immediately following the % as unescaped.
698 sk_write(p
->sub_socket
, "%", 1);
702 /* resume scanning for additional escapes after this one. */
706 /* if there is any unescaped text at the end of the line, send it */
708 sk_write(p
->sub_socket
, cfg
.proxy_telnet_command
+ so
, eo
- so
);
716 if (change
== PROXY_CHANGE_CLOSING
) {
717 /* if our proxy negotiation process involves closing and opening
718 * new sockets, then we would want to intercept this closing
719 * callback when we were expecting it. if we aren't anticipating
720 * a socket close, then some error must have occurred. we'll
721 * just pass those errors up to the backend.
723 return plug_closing(p
->plug
, p
->closing_error_msg
,
724 p
->closing_error_code
,
725 p
->closing_calling_back
);
728 if (change
== PROXY_CHANGE_SENT
) {
729 /* some (or all) of what we wrote to the proxy was sent.
730 * we don't do anything new, however, until we receive the
731 * proxy's response. we might want to set a timer so we can
732 * timeout the proxy negotiation after a while...
737 if (change
== PROXY_CHANGE_ACCEPTING
) {
738 /* we should _never_ see this, as we are using our socket to
739 * connect to a proxy, not accepting inbound connections.
740 * what should we do? close the socket with an appropriate
743 return plug_accepting(p
->plug
, p
->accepting_sock
);
746 if (change
== PROXY_CHANGE_RECEIVE
) {
747 /* we have received data from the underlying socket, which
748 * we'll need to parse, process, and respond to appropriately.
753 /* proxy activate will have dealt with
754 * whatever is left of the buffer */
758 plug_closing(p
->plug
, "Network error: Unexpected proxy error",
759 PROXY_ERROR_UNEXPECTED
, 0);