source: azure_iot_hub/trunk/curl-7.57.0/lib/socks.c@ 389

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1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, 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 */
51int 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 timediff_t timeleft;
61 *n = 0;
62 for(;;) {
63 timeleft = Curl_timeleft(conn->data, NULL, TRUE);
64 if(timeleft < 0) {
65 /* we already got the timeout */
66 result = CURLE_OPERATION_TIMEDOUT;
67 break;
68 }
69 if(SOCKET_READABLE(sockfd, timeleft) <= 0) {
70 result = ~CURLE_OK;
71 break;
72 }
73 result = Curl_read_plain(sockfd, buf, buffersize, &nread);
74 if(CURLE_AGAIN == result)
75 continue;
76 if(result)
77 break;
78
79 if(buffersize == nread) {
80 allread += nread;
81 *n = allread;
82 result = CURLE_OK;
83 break;
84 }
85 if(!nread) {
86 result = ~CURLE_OK;
87 break;
88 }
89
90 buffersize -= nread;
91 buf += nread;
92 allread += nread;
93 }
94 return result;
95}
96
97/*
98* This function logs in to a SOCKS4 proxy and sends the specifics to the final
99* destination server.
100*
101* Reference :
102* http://socks.permeo.com/protocol/socks4.protocol
103*
104* Note :
105* Set protocol4a=true for "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
106* Nonsupport "Identification Protocol (RFC1413)"
107*/
108CURLcode Curl_SOCKS4(const char *proxy_user,
109 const char *hostname,
110 int remote_port,
111 int sockindex,
112 struct connectdata *conn)
113{
114 const bool protocol4a =
115 (conn->socks_proxy.proxytype == CURLPROXY_SOCKS4A) ? TRUE : FALSE;
116#define SOCKS4REQLEN 262
117 unsigned char socksreq[SOCKS4REQLEN]; /* room for SOCKS4 request incl. user
118 id */
119 int result;
120 CURLcode code;
121 curl_socket_t sock = conn->sock[sockindex];
122 struct Curl_easy *data = conn->data;
123
124 if(Curl_timeleft(data, NULL, TRUE) < 0) {
125 /* time-out, bail out, go home */
126 failf(data, "Connection time-out");
127 return CURLE_OPERATION_TIMEDOUT;
128 }
129
130 if(conn->bits.httpproxy)
131 infof(conn->data, "SOCKS4%s: connecting to HTTP proxy %s port %d\n",
132 protocol4a ? "a" : "", hostname, remote_port);
133
134 (void)curlx_nonblock(sock, FALSE);
135
136 infof(data, "SOCKS4 communication to %s:%d\n", hostname, remote_port);
137
138 /*
139 * Compose socks4 request
140 *
141 * Request format
142 *
143 * +----+----+----+----+----+----+----+----+----+----+....+----+
144 * | VN | CD | DSTPORT | DSTIP | USERID |NULL|
145 * +----+----+----+----+----+----+----+----+----+----+....+----+
146 * # of bytes: 1 1 2 4 variable 1
147 */
148
149 socksreq[0] = 4; /* version (SOCKS4) */
150 socksreq[1] = 1; /* connect */
151 socksreq[2] = (unsigned char)((remote_port >> 8) & 0xff); /* PORT MSB */
152 socksreq[3] = (unsigned char)(remote_port & 0xff); /* PORT LSB */
153
154 /* DNS resolve only for SOCKS4, not SOCKS4a */
155 if(!protocol4a) {
156 struct Curl_dns_entry *dns;
157 Curl_addrinfo *hp = NULL;
158 int rc;
159
160 rc = Curl_resolv(conn, hostname, remote_port, &dns);
161
162 if(rc == CURLRESOLV_ERROR)
163 return CURLE_COULDNT_RESOLVE_PROXY;
164
165 if(rc == CURLRESOLV_PENDING)
166 /* ignores the return code, but 'dns' remains NULL on failure */
167 (void)Curl_resolver_wait_resolv(conn, &dns);
168
169 /*
170 * We cannot use 'hostent' as a struct that Curl_resolv() returns. It
171 * returns a Curl_addrinfo pointer that may not always look the same.
172 */
173 if(dns)
174 hp = dns->addr;
175 if(hp) {
176 char buf[64];
177 Curl_printable_address(hp, buf, sizeof(buf));
178
179 if(hp->ai_family == AF_INET) {
180 struct sockaddr_in *saddr_in;
181
182 saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr;
183 socksreq[4] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[0];
184 socksreq[5] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[1];
185 socksreq[6] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[2];
186 socksreq[7] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[3];
187
188 infof(data, "SOCKS4 connect to IPv4 %s (locally resolved)\n", buf);
189 }
190 else {
191 hp = NULL; /* fail! */
192
193 failf(data, "SOCKS4 connection to %s not supported\n", buf);
194 }
195
196 Curl_resolv_unlock(data, dns); /* not used anymore from now on */
197 }
198 if(!hp) {
199 failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
200 hostname);
201 return CURLE_COULDNT_RESOLVE_HOST;
202 }
203 }
204
205 /*
206 * This is currently not supporting "Identification Protocol (RFC1413)".
207 */
208 socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
209 if(proxy_user) {
210 size_t plen = strlen(proxy_user);
211 if(plen >= sizeof(socksreq) - 8) {
212 failf(data, "Too long SOCKS proxy name, can't use!\n");
213 return CURLE_COULDNT_CONNECT;
214 }
215 /* copy the proxy name WITH trailing zero */
216 memcpy(socksreq + 8, proxy_user, plen + 1);
217 }
218
219 /*
220 * Make connection
221 */
222 {
223 ssize_t actualread;
224 ssize_t written;
225 ssize_t hostnamelen = 0;
226 int packetsize = 9 +
227 (int)strlen((char *)socksreq + 8); /* size including NUL */
228
229 /* If SOCKS4a, set special invalid IP address 0.0.0.x */
230 if(protocol4a) {
231 socksreq[4] = 0;
232 socksreq[5] = 0;
233 socksreq[6] = 0;
234 socksreq[7] = 1;
235 /* If still enough room in buffer, also append hostname */
236 hostnamelen = (ssize_t)strlen(hostname) + 1; /* length including NUL */
237 if(packetsize + hostnamelen <= SOCKS4REQLEN)
238 strcpy((char *)socksreq + packetsize, hostname);
239 else
240 hostnamelen = 0; /* Flag: hostname did not fit in buffer */
241 }
242
243 /* Send request */
244 code = Curl_write_plain(conn, sock, (char *)socksreq,
245 packetsize + hostnamelen,
246 &written);
247 if(code || (written != packetsize + hostnamelen)) {
248 failf(data, "Failed to send SOCKS4 connect request.");
249 return CURLE_COULDNT_CONNECT;
250 }
251 if(protocol4a && hostnamelen == 0) {
252 /* SOCKS4a with very long hostname - send that name separately */
253 hostnamelen = (ssize_t)strlen(hostname) + 1;
254 code = Curl_write_plain(conn, sock, (char *)hostname, hostnamelen,
255 &written);
256 if(code || (written != hostnamelen)) {
257 failf(data, "Failed to send SOCKS4 connect request.");
258 return CURLE_COULDNT_CONNECT;
259 }
260 }
261
262 packetsize = 8; /* receive data size */
263
264 /* Receive response */
265 result = Curl_blockread_all(conn, sock, (char *)socksreq, packetsize,
266 &actualread);
267 if(result || (actualread != packetsize)) {
268 failf(data, "Failed to receive SOCKS4 connect request ack.");
269 return CURLE_COULDNT_CONNECT;
270 }
271
272 /*
273 * Response format
274 *
275 * +----+----+----+----+----+----+----+----+
276 * | VN | CD | DSTPORT | DSTIP |
277 * +----+----+----+----+----+----+----+----+
278 * # of bytes: 1 1 2 4
279 *
280 * VN is the version of the reply code and should be 0. CD is the result
281 * code with one of the following values:
282 *
283 * 90: request granted
284 * 91: request rejected or failed
285 * 92: request rejected because SOCKS server cannot connect to
286 * identd on the client
287 * 93: request rejected because the client program and identd
288 * report different user-ids
289 */
290
291 /* wrong version ? */
292 if(socksreq[0] != 0) {
293 failf(data,
294 "SOCKS4 reply has wrong version, version should be 4.");
295 return CURLE_COULDNT_CONNECT;
296 }
297
298 /* Result */
299 switch(socksreq[1]) {
300 case 90:
301 infof(data, "SOCKS4%s request granted.\n", protocol4a?"a":"");
302 break;
303 case 91:
304 failf(data,
305 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
306 ", request rejected or failed.",
307 (unsigned char)socksreq[4], (unsigned char)socksreq[5],
308 (unsigned char)socksreq[6], (unsigned char)socksreq[7],
309 (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]),
310 (unsigned char)socksreq[1]);
311 return CURLE_COULDNT_CONNECT;
312 case 92:
313 failf(data,
314 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
315 ", request rejected because SOCKS server cannot connect to "
316 "identd on the client.",
317 (unsigned char)socksreq[4], (unsigned char)socksreq[5],
318 (unsigned char)socksreq[6], (unsigned char)socksreq[7],
319 (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]),
320 (unsigned char)socksreq[1]);
321 return CURLE_COULDNT_CONNECT;
322 case 93:
323 failf(data,
324 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
325 ", request rejected because the client program and identd "
326 "report different user-ids.",
327 (unsigned char)socksreq[4], (unsigned char)socksreq[5],
328 (unsigned char)socksreq[6], (unsigned char)socksreq[7],
329 (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]),
330 (unsigned char)socksreq[1]);
331 return CURLE_COULDNT_CONNECT;
332 default:
333 failf(data,
334 "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
335 ", Unknown.",
336 (unsigned char)socksreq[4], (unsigned char)socksreq[5],
337 (unsigned char)socksreq[6], (unsigned char)socksreq[7],
338 (((unsigned char)socksreq[2] << 8) | (unsigned char)socksreq[3]),
339 (unsigned char)socksreq[1]);
340 return CURLE_COULDNT_CONNECT;
341 }
342 }
343
344 (void)curlx_nonblock(sock, TRUE);
345
346 return CURLE_OK; /* Proxy was successful! */
347}
348
349/*
350 * This function logs in to a SOCKS5 proxy and sends the specifics to the final
351 * destination server.
352 */
353CURLcode Curl_SOCKS5(const char *proxy_user,
354 const char *proxy_password,
355 const char *hostname,
356 int remote_port,
357 int sockindex,
358 struct connectdata *conn)
359{
360 /*
361 According to the RFC1928, section "6. Replies". This is what a SOCK5
362 replies:
363
364 +----+-----+-------+------+----------+----------+
365 |VER | REP | RSV | ATYP | BND.ADDR | BND.PORT |
366 +----+-----+-------+------+----------+----------+
367 | 1 | 1 | X'00' | 1 | Variable | 2 |
368 +----+-----+-------+------+----------+----------+
369
370 Where:
371
372 o VER protocol version: X'05'
373 o REP Reply field:
374 o X'00' succeeded
375 */
376
377 unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
378 int idx;
379 ssize_t actualread;
380 ssize_t written;
381 int result;
382 CURLcode code;
383 curl_socket_t sock = conn->sock[sockindex];
384 struct Curl_easy *data = conn->data;
385 timediff_t timeout;
386 bool socks5_resolve_local =
387 (conn->socks_proxy.proxytype == CURLPROXY_SOCKS5) ? TRUE : FALSE;
388 const size_t hostname_len = strlen(hostname);
389 ssize_t len = 0;
390 const unsigned long auth = data->set.socks5auth;
391 bool allow_gssapi = FALSE;
392
393 if(conn->bits.httpproxy)
394 infof(conn->data, "SOCKS5: connecting to HTTP proxy %s port %d\n",
395 hostname, remote_port);
396
397 /* RFC1928 chapter 5 specifies max 255 chars for domain name in packet */
398 if(!socks5_resolve_local && hostname_len > 255) {
399 infof(conn->data, "SOCKS5: server resolving disabled for hostnames of "
400 "length > 255 [actual len=%zu]\n", hostname_len);
401 socks5_resolve_local = TRUE;
402 }
403
404 /* get timeout */
405 timeout = Curl_timeleft(data, NULL, TRUE);
406
407 if(timeout < 0) {
408 /* time-out, bail out, go home */
409 failf(data, "Connection time-out");
410 return CURLE_OPERATION_TIMEDOUT;
411 }
412
413 (void)curlx_nonblock(sock, TRUE);
414
415 /* wait until socket gets connected */
416 result = SOCKET_WRITABLE(sock, timeout);
417
418 if(-1 == result) {
419 failf(conn->data, "SOCKS5: no connection here");
420 return CURLE_COULDNT_CONNECT;
421 }
422 if(0 == result) {
423 failf(conn->data, "SOCKS5: connection timeout");
424 return CURLE_OPERATION_TIMEDOUT;
425 }
426
427 if(result & CURL_CSELECT_ERR) {
428 failf(conn->data, "SOCKS5: error occurred during connection");
429 return CURLE_COULDNT_CONNECT;
430 }
431
432 if(auth & ~(CURLAUTH_BASIC | CURLAUTH_GSSAPI))
433 infof(conn->data,
434 "warning: unsupported value passed to CURLOPT_SOCKS5_AUTH: %lu\n",
435 auth);
436 if(!(auth & CURLAUTH_BASIC))
437 /* disable username/password auth */
438 proxy_user = NULL;
439#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
440 if(auth & CURLAUTH_GSSAPI)
441 allow_gssapi = TRUE;
442#endif
443
444 idx = 0;
445 socksreq[idx++] = 5; /* version */
446 idx++; /* reserve for the number of authentication methods */
447 socksreq[idx++] = 0; /* no authentication */
448 if(allow_gssapi)
449 socksreq[idx++] = 1; /* GSS-API */
450 if(proxy_user)
451 socksreq[idx++] = 2; /* username/password */
452 /* write the number of authentication methods */
453 socksreq[1] = (unsigned char) (idx - 2);
454
455 (void)curlx_nonblock(sock, FALSE);
456
457 infof(data, "SOCKS5 communication to %s:%d\n", hostname, remote_port);
458
459 code = Curl_write_plain(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
460 &written);
461 if(code || (written != (2 + (int)socksreq[1]))) {
462 failf(data, "Unable to send initial SOCKS5 request.");
463 return CURLE_COULDNT_CONNECT;
464 }
465
466 (void)curlx_nonblock(sock, TRUE);
467
468 result = SOCKET_READABLE(sock, timeout);
469
470 if(-1 == result) {
471 failf(conn->data, "SOCKS5 nothing to read");
472 return CURLE_COULDNT_CONNECT;
473 }
474 if(0 == result) {
475 failf(conn->data, "SOCKS5 read timeout");
476 return CURLE_OPERATION_TIMEDOUT;
477 }
478
479 if(result & CURL_CSELECT_ERR) {
480 failf(conn->data, "SOCKS5 read error occurred");
481 return CURLE_RECV_ERROR;
482 }
483
484 (void)curlx_nonblock(sock, FALSE);
485
486 result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread);
487 if(result || (actualread != 2)) {
488 failf(data, "Unable to receive initial SOCKS5 response.");
489 return CURLE_COULDNT_CONNECT;
490 }
491
492 if(socksreq[0] != 5) {
493 failf(data, "Received invalid version in initial SOCKS5 response.");
494 return CURLE_COULDNT_CONNECT;
495 }
496 if(socksreq[1] == 0) {
497 /* Nothing to do, no authentication needed */
498 ;
499 }
500#if defined(HAVE_GSSAPI) || defined(USE_WINDOWS_SSPI)
501 else if(allow_gssapi && (socksreq[1] == 1)) {
502 code = Curl_SOCKS5_gssapi_negotiate(sockindex, conn);
503 if(code) {
504 failf(data, "Unable to negotiate SOCKS5 GSS-API context.");
505 return CURLE_COULDNT_CONNECT;
506 }
507 }
508#endif
509 else if(socksreq[1] == 2) {
510 /* Needs user name and password */
511 size_t proxy_user_len, proxy_password_len;
512 if(proxy_user && proxy_password) {
513 proxy_user_len = strlen(proxy_user);
514 proxy_password_len = strlen(proxy_password);
515 }
516 else {
517 proxy_user_len = 0;
518 proxy_password_len = 0;
519 }
520
521 /* username/password request looks like
522 * +----+------+----------+------+----------+
523 * |VER | ULEN | UNAME | PLEN | PASSWD |
524 * +----+------+----------+------+----------+
525 * | 1 | 1 | 1 to 255 | 1 | 1 to 255 |
526 * +----+------+----------+------+----------+
527 */
528 len = 0;
529 socksreq[len++] = 1; /* username/pw subnegotiation version */
530 socksreq[len++] = (unsigned char) proxy_user_len;
531 if(proxy_user && proxy_user_len)
532 memcpy(socksreq + len, proxy_user, proxy_user_len);
533 len += proxy_user_len;
534 socksreq[len++] = (unsigned char) proxy_password_len;
535 if(proxy_password && proxy_password_len)
536 memcpy(socksreq + len, proxy_password, proxy_password_len);
537 len += proxy_password_len;
538
539 code = Curl_write_plain(conn, sock, (char *)socksreq, len, &written);
540 if(code || (len != written)) {
541 failf(data, "Failed to send SOCKS5 sub-negotiation request.");
542 return CURLE_COULDNT_CONNECT;
543 }
544
545 result = Curl_blockread_all(conn, sock, (char *)socksreq, 2, &actualread);
546 if(result || (actualread != 2)) {
547 failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
548 return CURLE_COULDNT_CONNECT;
549 }
550
551 /* ignore the first (VER) byte */
552 if(socksreq[1] != 0) { /* status */
553 failf(data, "User was rejected by the SOCKS5 server (%d %d).",
554 socksreq[0], socksreq[1]);
555 return CURLE_COULDNT_CONNECT;
556 }
557
558 /* Everything is good so far, user was authenticated! */
559 }
560 else {
561 /* error */
562 if(!allow_gssapi && (socksreq[1] == 1)) {
563 failf(data,
564 "SOCKS5 GSSAPI per-message authentication is not supported.");
565 return CURLE_COULDNT_CONNECT;
566 }
567 if(socksreq[1] == 255) {
568 if(!proxy_user || !*proxy_user) {
569 failf(data,
570 "No authentication method was acceptable. (It is quite likely"
571 " that the SOCKS5 server wanted a username/password, since none"
572 " was supplied to the server on this connection.)");
573 }
574 else {
575 failf(data, "No authentication method was acceptable.");
576 }
577 return CURLE_COULDNT_CONNECT;
578 }
579 else {
580 failf(data,
581 "Undocumented SOCKS5 mode attempted to be used by server.");
582 return CURLE_COULDNT_CONNECT;
583 }
584 }
585
586 /* Authentication is complete, now specify destination to the proxy */
587 len = 0;
588 socksreq[len++] = 5; /* version (SOCKS5) */
589 socksreq[len++] = 1; /* connect */
590 socksreq[len++] = 0; /* must be zero */
591
592 if(!socks5_resolve_local) {
593 socksreq[len++] = 3; /* ATYP: domain name = 3 */
594 socksreq[len++] = (char) hostname_len; /* address length */
595 memcpy(&socksreq[len], hostname, hostname_len); /* address str w/o NULL */
596 len += hostname_len;
597 }
598 else {
599 struct Curl_dns_entry *dns;
600 Curl_addrinfo *hp = NULL;
601 int rc = Curl_resolv(conn, hostname, remote_port, &dns);
602
603 if(rc == CURLRESOLV_ERROR)
604 return CURLE_COULDNT_RESOLVE_HOST;
605
606 if(rc == CURLRESOLV_PENDING) {
607 /* this requires that we're in "wait for resolve" state */
608 code = Curl_resolver_wait_resolv(conn, &dns);
609 if(code)
610 return code;
611 }
612
613 /*
614 * We cannot use 'hostent' as a struct that Curl_resolv() returns. It
615 * returns a Curl_addrinfo pointer that may not always look the same.
616 */
617 if(dns)
618 hp = dns->addr;
619 if(hp) {
620 int i;
621 char buf[64];
622 Curl_printable_address(hp, buf, sizeof(buf));
623
624 if(hp->ai_family == AF_INET) {
625 struct sockaddr_in *saddr_in;
626 socksreq[len++] = 1; /* ATYP: IPv4 = 1 */
627
628 saddr_in = (struct sockaddr_in *)(void *)hp->ai_addr;
629 for(i = 0; i < 4; i++) {
630 socksreq[len++] = ((unsigned char *)&saddr_in->sin_addr.s_addr)[i];
631 }
632
633 infof(data, "SOCKS5 connect to IPv4 %s (locally resolved)\n", buf);
634 }
635#ifdef ENABLE_IPV6
636 else if(hp->ai_family == AF_INET6) {
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 */
792
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