socks.c@ 94601

Last change on this file since 94601 was 85671, checked in by vboxsync, 4 years ago
Export out internal curl copy to make it a lot simpler to build VBox (OSE) on Windows. bugref:9814
Property svn:eol-style set to `native`
File size: 25.3 KB

Line
1	/***************************************************************************
2	* _ _ ____ _
3	* Project ___\| \| \| \| _ \\| \|
4	* / __\| \| \| \| \|_) \| \|
5	* \| (__\| \|_\| \| _ <\| \|___
6	* \___\|\___/\|_\| \_\_____\|
7	*
8	* Copyright (C) 1998 - 2018, Daniel Stenberg, <[email protected]>, et al.
9	*
10	* This software is licensed as described in the file COPYING, which
11	* you should have received as part of this distribution. The terms
12	* are also available at https://curl.haxx.se/docs/copyright.html.
13	*
14	* You may opt to use, copy, modify, merge, publish, distribute and/or sell
15	* copies of the Software, and permit persons to whom the Software is
16	* furnished to do so, under the terms of the COPYING file.
17	*
18	* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19	* KIND, either express or implied.
20	*
21	***************************************************************************/
22
23	#include "curl_setup.h"
24
25	#if !defined(CURL_DISABLE_PROXY)
26
27	#ifdef HAVE_NETINET_IN_H
28	#include <netinet/in.h>
29	#endif
30	#ifdef HAVE_ARPA_INET_H
31	#include <arpa/inet.h>
32	#endif
33
34	#include "urldata.h"
35	#include "sendf.h"
36	#include "select.h"
37	#include "connect.h"
38	#include "timeval.h"
39	#include "socks.h"
40
41	/* The last #include file should be: */
42	#include "memdebug.h"
43
44	/*
45	* Helper read-from-socket functions. Does the same as Curl_read() but it
46	* blocks until all bytes amount of buffersize will be read. No more, no less.
47	*
48	* This is STUPID BLOCKING behaviour which we frown upon, but right now this
49	* is what we have...
50	*/
51	int Curl_blockread_all(struct connectdata conn, / connection data */
52	curl_socket_t sockfd, /* read from this socket */
53	char buf, / store read data here */
54	ssize_t buffersize, /* max amount to read */
55	ssize_t n) / amount bytes read */
56	{
57	ssize_t nread;
58	ssize_t allread = 0;
59	int result;
60	*n = 0;
61	for(;;) {
62	timediff_t timeleft = Curl_timeleft(conn->data, NULL, TRUE);
63	if(timeleft < 0) {
64	/* we already got the timeout */
65	result = CURLE_OPERATION_TIMEDOUT;
66	break;
67	}
68	if(SOCKET_READABLE(sockfd, timeleft) <= 0) {
69	result = ~CURLE_OK;
70	break;
71	}
72	result = Curl_read_plain(sockfd, buf, buffersize, &nread);
73	if(CURLE_AGAIN == result)
74	continue;
75	if(result)
76	break;
77
78	if(buffersize == nread) {
79	allread += nread;
80	*n = allread;
81	result = CURLE_OK;
82	break;
83	}
84	if(!nread) {
85	result = ~CURLE_OK;
86	break;
87	}
88
89	buffersize -= nread;
90	buf += nread;
91	allread += nread;
92	}
93	return result;
94	}
95
96	/*
97	* This function logs in to a SOCKS4 proxy and sends the specifics to the final
98	* destination server.
99	*
100	* Reference :
101	* https://www.openssh.com/txt/socks4.protocol
102	*
103	* Note :
104	* Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
105	* Nonsupport "Identification Protocol (RFC1413)"
106	*/
107	CURLcode Curl_SOCKS4(const char *proxy_user,
108	const char *hostname,
109	int remote_port,
110	int sockindex,
111	struct connectdata *conn)
112	{
113	const bool protocol4a =
114	(conn->socks_proxy.proxytype == CURLPROXY_SOCKS4A) ? TRUE : FALSE;
115	#define SOCKS4REQLEN 262
116	unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user
117	id */
118	CURLcode code;
119	curl_socket_t sock = conn->sock[sockindex];
120	struct Curl_easy *data = conn->data;
121
122	if(Curl_timeleft(data, NULL, TRUE) < 0) {
123	/* time-out, bail out, go home */
124	failf(data, "Connection time-out");
125	return CURLE_OPERATION_TIMEDOUT;
126	}
127
128	if(conn->bits.httpproxy)
129	infof(conn->data, "SOCKS4%s: connecting to HTTP proxy %s port %d\n",
130	protocol4a ? "a" : "", hostname, remote_port);
131
132	(void)curlx_nonblock(sock, FALSE);
133
134	infof(data, "SOCKS4 communication to %s:%d\n", hostname, remote_port);
135
136	/*
137	* Compose socks4 request
138	*
139	* Request format
140	*
141	* +----+----+----+----+----+----+----+----+----+----+....+----+
142	* \| VN \| CD \| DSTPORT \| DSTIP \| USERID \|NULL\|
143	* +----+----+----+----+----+----+----+----+----+----+....+----+
144	* # of bytes: 1 1 2 4 variable 1
145	*/
146
147	socksreq[0] = 4; /* version (SOCKS4) */
148	socksreq[1] = 1; /* connect */
149	socksreq[2] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */
150	socksreq[3] = (unsigned char)(remote_port & 0xff); /* PORT LSB */
151
152	/* DNS resolve only for SOCKS4, not SOCKS4a */
153	if(!protocol4a) {
154	struct Curl_dns_entry *dns;
155	Curl_addrinfo *hp = NULL;
156	int rc;
157
158	rc = Curl_resolv(conn, hostname, remote_port, &dns);
159
160	if(rc == CURLRESOLV_ERROR)
161	return CURLE_COULDNT_RESOLVE_PROXY;
162
163	if(rc == CURLRESOLV_PENDING)
164	/* ignores the return code, but 'dns' remains NULL on failure */
165	(void)Curl_resolver_wait_resolv(conn, &dns);
166
167	/*
168	* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
169	* returns a Curl_addrinfo pointer that may not always look the same.
170	*/
171	if(dns)
172	hp = dns->addr;
173	if(hp) {
174	char buf[64];
175	Curl_printable_address(hp, buf, sizeof(buf));
176
177	if(hp->ai_family == AF_INET) {
178	struct sockaddr_in *saddr_in;
179
180	saddr_in = (struct sockaddr_in )(void )hp->ai_addr;
181	socksreq[4] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[0];
182	socksreq[5] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[1];
183	socksreq[6] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[2];
184	socksreq[7] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[3];
185
186	infof(data, "SOCKS4 connect to IPv4 %s (locally resolved)\n", buf);
187	}
188	else {
189	hp = NULL; /* fail! */
190
191	failf(data, "SOCKS4 connection to %s not supported\n", buf);
192	}
193
194	Curl_resolv_unlock(data, dns); /* not used anymore from now on */
195	}
196	if(!hp) {
197	failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
198	hostname);
199	return CURLE_COULDNT_RESOLVE_HOST;
200	}
201	}
202
203	/*
204	* This is currently not supporting "Identification Protocol (RFC1413)".
205	*/
206	socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
207	if(proxy_user) {
208	size_t plen = strlen(proxy_user);
209	if(plen >= sizeof(socksreq) - 8) {
210	failf(data, "Too long SOCKS proxy name, can't use!\n");
211	return CURLE_COULDNT_CONNECT;
212	}
213	/* copy the proxy name WITH trailing zero */
214	memcpy(socksreq + 8, proxy_user, plen + 1);
215	}
216
217	/*
218	* Make connection
219	*/
220	{
221	int result;
222	ssize_t actualread;
223	ssize_t written;
224	ssize_t hostnamelen = 0;
225	ssize_t packetsize = 9 +
226	strlen((char )socksreq + 8); / size including NUL */
227
228	/* If SOCKS4a, set special invalid IP address 0.0.0.x */
229	if(protocol4a) {
230	socksreq[4] = 0;
231	socksreq[5] = 0;
232	socksreq[6] = 0;
233	socksreq[7] = 1;
234	/* If still enough room in buffer, also append hostname */
235	hostnamelen = (ssize_t)strlen(hostname) + 1; /* length including NUL */
236	if(packetsize + hostnamelen <= SOCKS4REQLEN)
237	strcpy((char *)socksreq + packetsize, hostname);
238	else
239	hostnamelen = 0; /* Flag: hostname did not fit in buffer */
240	}
241
242	/* Send request */
243	code = Curl_write_plain(conn, sock, (char *)socksreq,
244	packetsize + hostnamelen,
245	&written);
246	if(code \|\| (written != packetsize + hostnamelen)) {
247	failf(data, "Failed to send SOCKS4 connect request.");
248	return CURLE_COULDNT_CONNECT;
249	}
250	if(protocol4a && hostnamelen == 0) {
251	/* SOCKS4a with very long hostname - send that name separately */
252	hostnamelen = (ssize_t)strlen(hostname) + 1;
253	code = Curl_write_plain(conn, sock, (char *)hostname, hostnamelen,
254	&written);
255	if(code \|\| (written != hostnamelen)) {
256	failf(data, "Failed to send SOCKS4 connect request.");
257	return CURLE_COULDNT_CONNECT;
258	}
259	}
260
261	packetsize = 8; /* receive data size */
262
263	/* Receive response */
264	result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
265	&actualread);
266	if(result \|\| (actualread != packetsize)) {
267	failf(data, "Failed to receive SOCKS4 connect request ack.");
268	return CURLE_COULDNT_CONNECT;
269	}
270
271	/*
272	* Response format
273	*
274	* +----+----+----+----+----+----+----+----+
275	* \| VN \| CD \| DSTPORT \| DSTIP \|
276	* +----+----+----+----+----+----+----+----+
277	* # of bytes: 1 1 2 4
278	*
279	* VN is the version of the reply code and should be 0. CD is the result
280	* code with one of the following values:
281	*
282	* 90: request granted
283	* 91: request rejected or failed
284	* 92: request rejected because SOCKS server cannot connect to
285	* identd on the client
286	* 93: request rejected because the client program and identd
287	* report different user-ids
288	*/
289
290	/* wrong version ? */
291	if(socksreq[0] != 0) {
292	failf(data,
293	"SOCKS4 reply has wrong version, version should be 4.");
294	return CURLE_COULDNT_CONNECT;
295	}
296
297	/* Result */
298	switch(socksreq[1]) {
299	case 90:
300	infof(data, "SOCKS4%s request granted.\n", protocol4a?"a":"");
301	break;
302	case 91:
303	failf(data,
304	"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
305	", request rejected or failed.",
306	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
307	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
308	(((unsigned char)socksreq[2] << 8) \| (unsigned char)socksreq[3]),
309	(unsigned char)socksreq[1]);
310	return CURLE_COULDNT_CONNECT;
311	case 92:
312	failf(data,
313	"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
314	", request rejected because SOCKS server cannot connect to "
315	"identd on the client.",
316	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
317	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
318	(((unsigned char)socksreq[2] << 8) \| (unsigned char)socksreq[3]),
319	(unsigned char)socksreq[1]);
320	return CURLE_COULDNT_CONNECT;
321	case 93:
322	failf(data,
323	"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
324	", request rejected because the client program and identd "
325	"report different user-ids.",
326	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
327	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
328	(((unsigned char)socksreq[2] << 8) \| (unsigned char)socksreq[3]),
329	(unsigned char)socksreq[1]);
330	return CURLE_COULDNT_CONNECT;
331	default:
332	failf(data,
333	"Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
334	", Unknown.",
335	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
336	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
337	(((unsigned char)socksreq[2] << 8) \| (unsigned char)socksreq[3]),
338	(unsigned char)socksreq[1]);
339	return CURLE_COULDNT_CONNECT;
340	}
341	}
342
343	(void)curlx_nonblock(sock, TRUE);
344
345	return CURLE_OK; /* Proxy was successful! */
346	}
347
348	/*
349	* This function logs in to a SOCKS5 proxy and sends the specifics to the final
350	* destination server.
351	*/
352	CURLcode Curl_SOCKS5(const char *proxy_user,
353	const char *proxy_password,
354	const char *hostname,
355	int remote_port,
356	int sockindex,
357	struct connectdata *conn)
358	{
359	/*
360	According to the RFC1928, section "6. Replies". This is what a SOCK5
361	replies:
362
363	+----+-----+-------+------+----------+----------+
364	\|VER \| REP \| RSV \| ATYP \| BND.ADDR \| BND.PORT \|
365	+----+-----+-------+------+----------+----------+
366	\| 1 \| 1 \| X'00' \| 1 \| Variable \| 2 \|
367	+----+-----+-------+------+----------+----------+
368
369	Where:
370
371	o VER protocol version: X'05'
372	o REP Reply field:
373	o X'00' succeeded
374	*/
375
376	unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
377	int idx;
378	ssize_t actualread;
379	ssize_t written;
380	int result;
381	CURLcode code;
382	curl_socket_t sock = conn->sock[sockindex];
383	struct Curl_easy *data = conn->data;
384	timediff_t timeout;
385	bool socks5_resolve_local =
386	(conn->socks_proxy.proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE;
387	const size_t hostname_len = strlen(hostname);
388	ssize_t len = 0;
389	const unsigned long auth = data->set.socks5auth;
390	bool allow_gssapi = FALSE;
391
392	if(conn->bits.httpproxy)
393	infof(conn->data, "SOCKS5: connecting to HTTP proxy %s port %d\n",
394	hostname, remote_port);
395
396	/* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */
397	if(!socks5_resolve_local && hostname_len > 255) {
398	infof(conn->data, "SOCKS5: server resolving disabled for hostnames of "
399	"length > 255 [actual len=%zu]\n", hostname_len);
400	socks5_resolve_local = TRUE;
401	}
402
403	/* get timeout */
404	timeout = Curl_timeleft(data, NULL, TRUE);
405
406	if(timeout < 0) {
407	/* time-out, bail out, go home */
408	failf(data, "Connection time-out");
409	return CURLE_OPERATION_TIMEDOUT;
410	}
411
412	(void)curlx_nonblock(sock, TRUE);
413
414	/* wait until socket gets connected */
415	result = SOCKET_WRITABLE(sock, timeout);
416
417	if(-1 == result) {
418	failf(conn->data, "SOCKS5: no connection here");
419	return CURLE_COULDNT_CONNECT;
420	}
421	if(0 == result) {
422	failf(conn->data, "SOCKS5: connection timeout");
423	return CURLE_OPERATION_TIMEDOUT;
424	}
425
426	if(result & CURL_CSELECT_ERR) {
427	failf(conn->data, "SOCKS5: error occurred during connection");
428	return CURLE_COULDNT_CONNECT;
429	}
430
431	if(auth & ~(CURLAUTH_BASIC \| CURLAUTH_GSSAPI))
432	infof(conn->data,
433	"warning: unsupported value passed to CURLOPT_SOCKS5_AUTH: %lu\n",
434	auth);
435	if(!(auth & CURLAUTH_BASIC))
436	/* disable username/password auth */
437	proxy_user = NULL;
438	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
439	if(auth & CURLAUTH_GSSAPI)
440	allow_gssapi = TRUE;
441	#endif
442
443	idx = 0;
444	socksreq[idx++] = 5; /* version */
445	idx++; /* reserve for the number of authentication methods */
446	socksreq[idx++] = 0; /* no authentication */
447	if(allow_gssapi)
448	socksreq[idx++] = 1; /* GSS-API */
449	if(proxy_user)
450	socksreq[idx++] = 2; /* username/password */
451	/* write the number of authentication methods */
452	socksreq[1] = (unsigned char) (idx - 2);
453
454	(void)curlx_nonblock(sock, FALSE);
455
456	infof(data, "SOCKS5 communication to %s:%d\n", hostname, remote_port);
457
458	code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
459	&written);
460	if(code \|\| (written != (2 + (int)socksreq[1]))) {
461	failf(data, "Unable to send initial SOCKS5 request.");
462	return CURLE_COULDNT_CONNECT;
463	}
464
465	(void)curlx_nonblock(sock, TRUE);
466
467	result = SOCKET_READABLE(sock, timeout);
468
469	if(-1 == result) {
470	failf(conn->data, "SOCKS5 nothing to read");
471	return CURLE_COULDNT_CONNECT;
472	}
473	if(0 == result) {
474	failf(conn->data, "SOCKS5 read timeout");
475	return CURLE_OPERATION_TIMEDOUT;
476	}
477
478	if(result & CURL_CSELECT_ERR) {
479	failf(conn->data, "SOCKS5 read error occurred");
480	return CURLE_RECV_ERROR;
481	}
482
483	(void)curlx_nonblock(sock, FALSE);
484
485	result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread);
486	if(result \|\| (actualread != 2)) {
487	failf(data, "Unable to receive initial SOCKS5 response.");
488	return CURLE_COULDNT_CONNECT;
489	}
490
491	if(socksreq[0] != 5) {
492	failf(data, "Received invalid version in initial SOCKS5 response.");
493	return CURLE_COULDNT_CONNECT;
494	}
495	if(socksreq[1] == 0) {
496	/* Nothing to do, no authentication needed */
497	;
498	}
499	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
500	else if(allow_gssapi && (socksreq[1] == 1)) {
501	code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn);
502	if(code) {
503	failf(data, "Unable to negotiate SOCKS5 GSS-API context.");
504	return CURLE_COULDNT_CONNECT;
505	}
506	}
507	#endif
508	else if(socksreq[1] == 2) {
509	/* Needs user name and password */
510	size_t proxy_user_len, proxy_password_len;
511	if(proxy_user && proxy_password) {
512	proxy_user_len = strlen(proxy_user);
513	proxy_password_len = strlen(proxy_password);
514	}
515	else {
516	proxy_user_len = 0;
517	proxy_password_len = 0;
518	}
519
520	/* username/password request looks like
521	* +----+------+----------+------+----------+
522	* \|VER \| ULEN \| UNAME \| PLEN \| PASSWD \|
523	* +----+------+----------+------+----------+
524	* \| 1 \| 1 \| 1 to 255 \| 1 \| 1 to 255 \|
525	* +----+------+----------+------+----------+
526	*/
527	len = 0;
528	socksreq[len++] = 1; /* username/pw subnegotiation version */
529	socksreq[len++] = (unsigned char) proxy_user_len;
530	if(proxy_user && proxy_user_len)
531	memcpy(socksreq + len, proxy_user, proxy_user_len);
532	len += proxy_user_len;
533	socksreq[len++] = (unsigned char) proxy_password_len;
534	if(proxy_password && proxy_password_len)
535	memcpy(socksreq + len, proxy_password, proxy_password_len);
536	len += proxy_password_len;
537
538	code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written);
539	if(code \|\| (len != written)) {
540	failf(data, "Failed to send SOCKS5 sub-negotiation request.");
541	return CURLE_COULDNT_CONNECT;
542	}
543
544	result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread);
545	if(result \|\| (actualread != 2)) {
546	failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
547	return CURLE_COULDNT_CONNECT;
548	}
549
550	/* ignore the first (VER) byte */
551	if(socksreq[1] != 0) { /* status */
552	failf(data, "User was rejected by the SOCKS5 server (%d %d).",
553	socksreq[0], socksreq[1]);
554	return CURLE_COULDNT_CONNECT;
555	}
556
557	/* Everything is good so far, user was authenticated! */
558	}
559	else {
560	/* error */
561	if(!allow_gssapi && (socksreq[1] == 1)) {
562	failf(data,
563	"SOCKS5 GSSAPI per-message authentication is not supported.");
564	return CURLE_COULDNT_CONNECT;
565	}
566	if(socksreq[1] == 255) {
567	if(!proxy_user \|\| !*proxy_user) {
568	failf(data,
569	"No authentication method was acceptable. (It is quite likely"
570	" that the SOCKS5 server wanted a username/password, since none"
571	" was supplied to the server on this connection.)");
572	}
573	else {
574	failf(data, "No authentication method was acceptable.");
575	}
576	return CURLE_COULDNT_CONNECT;
577	}
578	else {
579	failf(data,
580	"Undocumented SOCKS5 mode attempted to be used by server.");
581	return CURLE_COULDNT_CONNECT;
582	}
583	}
584
585	/* Authentication is complete, now specify destination to the proxy */
586	len = 0;
587	socksreq[len++] = 5; /* version (SOCKS5) */
588	socksreq[len++] = 1; /* connect */
589	socksreq[len++] = 0; /* must be zero */
590
591	if(!socks5_resolve_local) {
592	socksreq[len++] = 3; /* ATYP: domain name = 3 */
593	socksreq[len++] = (char) hostname_len; /* address length */
594	memcpy(&socksreq[len], hostname, hostname_len); /* address str w/o NULL */
595	len += hostname_len;
596	}
597	else {
598	struct Curl_dns_entry *dns;
599	Curl_addrinfo *hp = NULL;
600	int rc = Curl_resolv(conn, hostname, remote_port, &dns);
601
602	if(rc == CURLRESOLV_ERROR)
603	return CURLE_COULDNT_RESOLVE_HOST;
604
605	if(rc == CURLRESOLV_PENDING) {
606	/* this requires that we're in "wait for resolve" state */
607	code = Curl_resolver_wait_resolv(conn, &dns);
608	if(code)
609	return code;
610	}
611
612	/*
613	* We cannot use 'hostent' as a struct that Curl_resolv() returns. It
614	* returns a Curl_addrinfo pointer that may not always look the same.
615	*/
616	if(dns)
617	hp = dns->addr;
618	if(hp) {
619	char buf[64];
620	Curl_printable_address(hp, buf, sizeof(buf));
621
622	if(hp->ai_family == AF_INET) {
623	int i;
624	struct sockaddr_in *saddr_in;
625	socksreq[len++] = 1; /* ATYP: IPv4 = 1 */
626
627	saddr_in = (struct sockaddr_in )(void )hp->ai_addr;
628	for(i = 0; i < 4; i++) {
629	socksreq[len++] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[i];
630	}
631
632	infof(data, "SOCKS5 connect to IPv4 %s (locally resolved)\n", buf);
633	}
634	#ifdef ENABLE_IPV6
635	else if(hp->ai_family == AF_INET6) {
636	int i;
637	struct sockaddr_in6 *saddr_in6;
638	socksreq[len++] = 4; /* ATYP: IPv6 = 4 */
639
640	saddr_in6 = (struct sockaddr_in6 )(void )hp->ai_addr;
641	for(i = 0; i < 16; i++) {
642	socksreq[len++] =
643	((unsigned char *)&saddr_in6->sin6_addr.s6_addr)[i];
644	}
645
646	infof(data, "SOCKS5 connect to IPv6 %s (locally resolved)\n", buf);
647	}
648	#endif
649	else {
650	hp = NULL; /* fail! */
651
652	failf(data, "SOCKS5 connection to %s not supported\n", buf);
653	}
654
655	Curl_resolv_unlock(data, dns); /* not used anymore from now on */
656	}
657	if(!hp) {
658	failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
659	hostname);
660	return CURLE_COULDNT_RESOLVE_HOST;
661	}
662	}
663
664	socksreq[len++] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */
665	socksreq[len++] = (unsigned char)(remote_port & 0xff); /* PORT LSB */
666
667	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
668	if(conn->socks5_gssapi_enctype) {
669	failf(data, "SOCKS5 GSS-API protection not yet implemented.");
670	}
671	else
672	#endif
673	code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written);
674
675	if(code \|\| (len != written)) {
676	failf(data, "Failed to send SOCKS5 connect request.");
677	return CURLE_COULDNT_CONNECT;
678	}
679
680	len = 10; /* minimum packet size is 10 */
681
682	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
683	if(conn->socks5_gssapi_enctype) {
684	failf(data, "SOCKS5 GSS-API protection not yet implemented.");
685	}
686	else
687	#endif
688	result = Curl_blockread_all(conn, sock, (char *)socksreq,
689	len, &actualread);
690
691	if(result \|\| (len != actualread)) {
692	failf(data, "Failed to receive SOCKS5 connect request ack.");
693	return CURLE_COULDNT_CONNECT;
694	}
695
696	if(socksreq[0] != 5) { /* version */
697	failf(data,
698	"SOCKS5 reply has wrong version, version should be 5.");
699	return CURLE_COULDNT_CONNECT;
700	}
701
702	/* Fix: in general, returned BND.ADDR is variable length parameter by RFC
703	1928, so the reply packet should be read until the end to avoid errors at
704	subsequent protocol level.
705
706	+----+-----+-------+------+----------+----------+
707	\|VER \| REP \| RSV \| ATYP \| BND.ADDR \| BND.PORT \|
708	+----+-----+-------+------+----------+----------+
709	\| 1 \| 1 \| X'00' \| 1 \| Variable \| 2 \|
710	+----+-----+-------+------+----------+----------+
711
712	ATYP:
713	o IP v4 address: X'01', BND.ADDR = 4 byte
714	o domain name: X'03', BND.ADDR = [ 1 byte length, string ]
715	o IP v6 address: X'04', BND.ADDR = 16 byte
716	*/
717
718	/* Calculate real packet size */
719	if(socksreq[3] == 3) {
720	/* domain name */
721	int addrlen = (int) socksreq[4];
722	len = 5 + addrlen + 2;
723	}
724	else if(socksreq[3] == 4) {
725	/* IPv6 */
726	len = 4 + 16 + 2;
727	}
728
729	/* At this point we already read first 10 bytes */
730	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
731	if(!conn->socks5_gssapi_enctype) {
732	/* decrypt_gssapi_blockread already read the whole packet */
733	#endif
734	if(len > 10) {
735	result = Curl_blockread_all(conn, sock, (char *)&socksreq[10],
736	len - 10, &actualread);
737	if(result \|\| ((len - 10) != actualread)) {
738	failf(data, "Failed to receive SOCKS5 connect request ack.");
739	return CURLE_COULDNT_CONNECT;
740	}
741	}
742	#if defined(HAVE_GSSAPI) \|\| defined(USE_WINDOWS_SSPI)
743	}
744	#endif
745
746	if(socksreq[1] != 0) { /* Anything besides 0 is an error */
747	if(socksreq[3] == 1) {
748	failf(data,
749	"Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
750	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
751	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
752	(((unsigned char)socksreq[8] << 8) \|
753	(unsigned char)socksreq[9]),
754	(unsigned char)socksreq[1]);
755	}
756	else if(socksreq[3] == 3) {
757	unsigned char port_upper = (unsigned char)socksreq[len - 2];
758	socksreq[len - 2] = 0;
759	failf(data,
760	"Can't complete SOCKS5 connection to %s:%d. (%d)",
761	(char *)&socksreq[5],
762	((port_upper << 8) \|
763	(unsigned char)socksreq[len - 1]),
764	(unsigned char)socksreq[1]);
765	socksreq[len - 2] = port_upper;
766	}
767	else if(socksreq[3] == 4) {
768	failf(data,
769	"Can't complete SOCKS5 connection to %02x%02x:%02x%02x:"
770	"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%d. (%d)",
771	(unsigned char)socksreq[4], (unsigned char)socksreq[5],
772	(unsigned char)socksreq[6], (unsigned char)socksreq[7],
773	(unsigned char)socksreq[8], (unsigned char)socksreq[9],
774	(unsigned char)socksreq[10], (unsigned char)socksreq[11],
775	(unsigned char)socksreq[12], (unsigned char)socksreq[13],
776	(unsigned char)socksreq[14], (unsigned char)socksreq[15],
777	(unsigned char)socksreq[16], (unsigned char)socksreq[17],
778	(unsigned char)socksreq[18], (unsigned char)socksreq[19],
779	(((unsigned char)socksreq[20] << 8) \|
780	(unsigned char)socksreq[21]),
781	(unsigned char)socksreq[1]);
782	}
783	return CURLE_COULDNT_CONNECT;
784	}
785	infof(data, "SOCKS5 request granted.\n");
786
787	(void)curlx_nonblock(sock, TRUE);
788	return CURLE_OK; /* Proxy was successful! */
789	}
790
791	#endif /* CURL_DISABLE_PROXY */

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source: vbox/trunk/src/libs/curl-7.64.0/lib/socks.c@ 94601

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