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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/nc/socks.c	Lines:	0	188	0.0 %
Date:	2017-11-07	Branches:	0	120	0.0 %


/*	$OpenBSD: socks.c,v 1.24 2016/06/27 14:43:04 deraadt Exp $	*/

/*
 * Copyright (c) 1999 Niklas Hallqvist.  All rights reserved.
 * Copyright (c) 2004, 2005 Damien Miller.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <resolv.h>
#include <readpassphrase.h>
#include "atomicio.h"

#define SOCKS_PORT	"1080"
#define HTTP_PROXY_PORT	"3128"
#define HTTP_MAXHDRS	64
#define SOCKS_V5	5
#define SOCKS_V4	4
#define SOCKS_NOAUTH	0
#define SOCKS_NOMETHOD	0xff
#define SOCKS_CONNECT	1
#define SOCKS_IPV4	1
#define SOCKS_DOMAIN	3
#define SOCKS_IPV6	4

int	remote_connect(const char *, const char *, struct addrinfo);
int	socks_connect(const char *, const char *, struct addrinfo,
	    const char *, const char *, struct addrinfo, int,
	    const char *);

static int
decode_addrport(const char *h, const char *p, struct sockaddr *addr,
    socklen_t addrlen, int v4only, int numeric)
{
	int r;
	struct addrinfo hints, *res;

	bzero(&hints, sizeof(hints));
	hints.ai_family = v4only ? PF_INET : PF_UNSPEC;
	hints.ai_flags = numeric ? AI_NUMERICHOST : 0;
	hints.ai_socktype = SOCK_STREAM;
	r = getaddrinfo(h, p, &hints, &res);
	/* Don't fatal when attempting to convert a numeric address */
	if (r != 0) {
		if (!numeric) {
			errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p,
			    gai_strerror(r));
		}
		return (-1);
	}
	if (addrlen < res->ai_addrlen) {
		freeaddrinfo(res);
		errx(1, "internal error: addrlen < res->ai_addrlen");
	}
	memcpy(addr, res->ai_addr, res->ai_addrlen);
	freeaddrinfo(res);
	return (0);
}

static int
proxy_read_line(int fd, char *buf, size_t bufsz)
{
	size_t off;

	for(off = 0;;) {
		if (off >= bufsz)
			errx(1, "proxy read too long");
		if (atomicio(read, fd, buf + off, 1) != 1)
			err(1, "proxy read");
		/* Skip CR */
		if (buf[off] == '\r')
			continue;
		if (buf[off] == '\n') {
			buf[off] = '\0';
			break;
		}
		off++;
	}
	return (off);
}

static const char *
getproxypass(const char *proxyuser, const char *proxyhost)
{
	char prompt[512];
	static char pw[256];

	snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ",
	   proxyuser, proxyhost);
	if (readpassphrase(prompt, pw, sizeof(pw), RPP_REQUIRE_TTY) == NULL)
		errx(1, "Unable to read proxy passphrase");
	return (pw);
}

/*
 * Error strings adapted from the generally accepted SOCKSv4 spec:
 *
 * http://ftp.icm.edu.pl/packages/socks/socks4/SOCKS4.protocol
 */
static const char *
socks4_strerror(int e)
{
	switch (e) {
	case 90:
		return "Succeeded";
	case 91:
		return "Request rejected or failed";
	case 92:
		return "SOCKS server cannot connect to identd on the client";
	case 93:
		return "Client program and identd report different user-ids";
	default:
		return "Unknown error";
	}
}

/*
 * Error strings taken almost directly from RFC 1928.
 */
static const char *
socks5_strerror(int e)
{
	switch (e) {
	case 0:
		return "Succeeded";
	case 1:
		return "General SOCKS server failure";
	case 2:
		return "Connection not allowed by ruleset";
	case 3:
		return "Network unreachable";
	case 4:
		return "Host unreachable";
	case 5:
		return "Connection refused";
	case 6:
		return "TTL expired";
	case 7:
		return "Command not supported";
	case 8:
		return "Address type not supported";
	default:
		return "Unknown error";
	}
}

int
socks_connect(const char *host, const char *port,
    struct addrinfo hints __attribute__ ((__unused__)),
    const char *proxyhost, const char *proxyport, struct addrinfo proxyhints,
    int socksv, const char *proxyuser)
{
	int proxyfd, r, authretry = 0;
	size_t hlen, wlen;
	unsigned char buf[1024];
	size_t cnt;
	struct sockaddr_storage addr;
	struct sockaddr_in *in4 = (struct sockaddr_in *)&addr;
	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr;
	in_port_t serverport;
	const char *proxypass = NULL;

	if (proxyport == NULL)
		proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT;

	/* Abuse API to lookup port */
	if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr,
	    sizeof(addr), 1, 1) == -1)
		errx(1, "unknown port \"%.64s\"", port);
	serverport = in4->sin_port;

 again:
	if (authretry++ > 3)
		errx(1, "Too many authentication failures");

	proxyfd = remote_connect(proxyhost, proxyport, proxyhints);

	if (proxyfd < 0)
		return (-1);

	if (socksv == 5) {
		if (decode_addrport(host, port, (struct sockaddr *)&addr,
		    sizeof(addr), 0, 1) == -1)
			addr.ss_family = 0; /* used in switch below */

		/* Version 5, one method: no authentication */
		buf[0] = SOCKS_V5;
		buf[1] = 1;
		buf[2] = SOCKS_NOAUTH;
		cnt = atomicio(vwrite, proxyfd, buf, 3);
		if (cnt != 3)
			err(1, "write failed (%zu/3)", cnt);

		cnt = atomicio(read, proxyfd, buf, 2);
		if (cnt != 2)
			err(1, "read failed (%zu/3)", cnt);

		if (buf[1] == SOCKS_NOMETHOD)
			errx(1, "authentication method negotiation failed");

		switch (addr.ss_family) {
		case 0:
			/* Version 5, connect: domain name */

			/* Max domain name length is 255 bytes */
			hlen = strlen(host);
			if (hlen > 255)
				errx(1, "host name too long for SOCKS5");
			buf[0] = SOCKS_V5;
			buf[1] = SOCKS_CONNECT;
			buf[2] = 0;
			buf[3] = SOCKS_DOMAIN;
			buf[4] = hlen;
			memcpy(buf + 5, host, hlen);
			memcpy(buf + 5 + hlen, &serverport, sizeof serverport);
			wlen = 7 + hlen;
			break;
		case AF_INET:
			/* Version 5, connect: IPv4 address */
			buf[0] = SOCKS_V5;
			buf[1] = SOCKS_CONNECT;
			buf[2] = 0;
			buf[3] = SOCKS_IPV4;
			memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
			memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port);
			wlen = 10;
			break;
		case AF_INET6:
			/* Version 5, connect: IPv6 address */
			buf[0] = SOCKS_V5;
			buf[1] = SOCKS_CONNECT;
			buf[2] = 0;
			buf[3] = SOCKS_IPV6;
			memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr);
			memcpy(buf + 20, &in6->sin6_port,
			    sizeof in6->sin6_port);
			wlen = 22;
			break;
		default:
			errx(1, "internal error: silly AF");
		}

		cnt = atomicio(vwrite, proxyfd, buf, wlen);
		if (cnt != wlen)
			err(1, "write failed (%zu/%zu)", cnt, wlen);

		cnt = atomicio(read, proxyfd, buf, 4);
		if (cnt != 4)
			err(1, "read failed (%zu/4)", cnt);
		if (buf[1] != 0) {
			errx(1, "connection failed, SOCKSv5 error: %s",
			    socks5_strerror(buf[1]));
		}
		switch (buf[3]) {
		case SOCKS_IPV4:
			cnt = atomicio(read, proxyfd, buf + 4, 6);
			if (cnt != 6)
				err(1, "read failed (%zu/6)", cnt);
			break;
		case SOCKS_IPV6:
			cnt = atomicio(read, proxyfd, buf + 4, 18);
			if (cnt != 18)
				err(1, "read failed (%zu/18)", cnt);
			break;
		default:
			errx(1, "connection failed, unsupported address type");
		}
	} else if (socksv == 4) {
		/* This will exit on lookup failure */
		decode_addrport(host, port, (struct sockaddr *)&addr,
		    sizeof(addr), 1, 0);

		/* Version 4 */
		buf[0] = SOCKS_V4;
		buf[1] = SOCKS_CONNECT;	/* connect */
		memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port);
		memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
		buf[8] = 0;	/* empty username */
		wlen = 9;

		cnt = atomicio(vwrite, proxyfd, buf, wlen);
		if (cnt != wlen)
			err(1, "write failed (%zu/%zu)", cnt, wlen);

		cnt = atomicio(read, proxyfd, buf, 8);
		if (cnt != 8)
			err(1, "read failed (%zu/8)", cnt);
		if (buf[1] != 90) {
			errx(1, "connection failed, SOCKSv4 error: %s",
			    socks4_strerror(buf[1]));
		}
	} else if (socksv == -1) {
		/* HTTP proxy CONNECT */

		/* Disallow bad chars in hostname */
		if (strcspn(host, "\r\n\t []:") != strlen(host))
			errx(1, "Invalid hostname");

		/* Try to be sane about numeric IPv6 addresses */
		if (strchr(host, ':') != NULL) {
			r = snprintf(buf, sizeof(buf),
			    "CONNECT [%s]:%d HTTP/1.0\r\n",
			    host, ntohs(serverport));
		} else {
			r = snprintf(buf, sizeof(buf),
			    "CONNECT %s:%d HTTP/1.0\r\n",
			    host, ntohs(serverport));
		}
		if (r == -1 || (size_t)r >= sizeof(buf))
			errx(1, "hostname too long");
		r = strlen(buf);

		cnt = atomicio(vwrite, proxyfd, buf, r);
		if (cnt != r)
			err(1, "write failed (%zu/%d)", cnt, r);

		if (authretry > 1) {
			char resp[1024];

			proxypass = getproxypass(proxyuser, proxyhost);
			r = snprintf(buf, sizeof(buf), "%s:%s",
			    proxyuser, proxypass);
			if (r == -1 || (size_t)r >= sizeof(buf) ||
			    b64_ntop(buf, strlen(buf), resp,
			    sizeof(resp)) == -1)
				errx(1, "Proxy username/password too long");
			r = snprintf(buf, sizeof(buf), "Proxy-Authorization: "
			    "Basic %s\r\n", resp);
			if (r == -1 || (size_t)r >= sizeof(buf))
				errx(1, "Proxy auth response too long");
			r = strlen(buf);
			if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r)
				err(1, "write failed (%zu/%d)", cnt, r);
		}

		/* Terminate headers */
		if ((cnt = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2)
			err(1, "write failed (%zu/2)", cnt);

		/* Read status reply */
		proxy_read_line(proxyfd, buf, sizeof(buf));
		if (proxyuser != NULL &&
		    strncmp(buf, "HTTP/1.0 407 ", 12) == 0) {
			if (authretry > 1) {
				fprintf(stderr, "Proxy authentication "
				    "failed\n");
			}
			close(proxyfd);
			goto again;
		} else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 &&
		    strncmp(buf, "HTTP/1.1 200 ", 12) != 0)
			errx(1, "Proxy error: \"%s\"", buf);

		/* Headers continue until we hit an empty line */
		for (r = 0; r < HTTP_MAXHDRS; r++) {
			proxy_read_line(proxyfd, buf, sizeof(buf));
			if (*buf == '\0')
				break;
		}
		if (*buf != '\0')
			errx(1, "Too many proxy headers received");
	} else
		errx(1, "Unknown proxy protocol %d", socksv);

	return (proxyfd);
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: socks.c,v 1.24 2016/06/27 14:43:04 deraadt Exp $ */
2
3			/*
4			* Copyright (c) 1999 Niklas Hallqvist. All rights reserved.
5			* Copyright (c) 2004, 2005 Damien Miller. All rights reserved.
6			*
7			* Redistribution and use in source and binary forms, with or without
8			* modification, are permitted provided that the following conditions
9			* are met:
10			* 1. Redistributions of source code must retain the above copyright
11			* notice, this list of conditions and the following disclaimer.
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the distribution.
15			*
16			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17			* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18			* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19			* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20			* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21			* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25			* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26			*/
27
28			#include <sys/types.h>
29			#include <sys/socket.h>
30			#include <netinet/in.h>
31			#include <arpa/inet.h>
32
33			#include <err.h>
34			#include <errno.h>
35			#include <netdb.h>
36			#include <stdio.h>
37			#include <stdlib.h>
38			#include <string.h>
39			#include <unistd.h>
40			#include <resolv.h>
41			#include <readpassphrase.h>
42			#include "atomicio.h"
43
44			#define SOCKS_PORT "1080"
45			#define HTTP_PROXY_PORT "3128"
46			#define HTTP_MAXHDRS 64
47			#define SOCKS_V5 5
48			#define SOCKS_V4 4
49			#define SOCKS_NOAUTH 0
50			#define SOCKS_NOMETHOD 0xff
51			#define SOCKS_CONNECT 1
52			#define SOCKS_IPV4 1
53			#define SOCKS_DOMAIN 3
54			#define SOCKS_IPV6 4
55
56			int remote_connect(const char , const char , struct addrinfo);
57			int socks_connect(const char , const char , struct addrinfo,
58			const char , const char , struct addrinfo, int,
59			const char *);
60
61			static int
62			decode_addrport(const char h, const char p, struct sockaddr *addr,
63			socklen_t addrlen, int v4only, int numeric)
64			{
65			int r;
66			struct addrinfo hints, *res;
67
68			bzero(&hints, sizeof(hints));
69			hints.ai_family = v4only ? PF_INET : PF_UNSPEC;
70			hints.ai_flags = numeric ? AI_NUMERICHOST : 0;
71			hints.ai_socktype = SOCK_STREAM;
72			r = getaddrinfo(h, p, &hints, &res);
73			/* Don't fatal when attempting to convert a numeric address */
74			if (r != 0) {
75			if (!numeric) {
76			errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p,
77			gai_strerror(r));
78			}
79			return (-1);
80			}
81			if (addrlen < res->ai_addrlen) {
82			freeaddrinfo(res);
83			errx(1, "internal error: addrlen < res->ai_addrlen");
84			}
85			memcpy(addr, res->ai_addr, res->ai_addrlen);
86			freeaddrinfo(res);
87			return (0);
88			}
89
90			static int
91			proxy_read_line(int fd, char *buf, size_t bufsz)
92			{
93			size_t off;
94
95			for(off = 0;;) {
96			if (off >= bufsz)
97			errx(1, "proxy read too long");
98			if (atomicio(read, fd, buf + off, 1) != 1)
99			err(1, "proxy read");
100			/* Skip CR */
101			if (buf[off] == '\r')
102			continue;
103			if (buf[off] == '\n') {
104			buf[off] = '\0';
105			break;
106			}
107			off++;
108			}
109			return (off);
110			}
111
112			static const char *
113			getproxypass(const char proxyuser, const char proxyhost)
114			{
115			char prompt[512];
116			static char pw[256];
117
118			snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ",
119			proxyuser, proxyhost);
120			if (readpassphrase(prompt, pw, sizeof(pw), RPP_REQUIRE_TTY) == NULL)
121			errx(1, "Unable to read proxy passphrase");
122			return (pw);
123			}
124
125			/*
126			* Error strings adapted from the generally accepted SOCKSv4 spec:
127			*
128			* http://ftp.icm.edu.pl/packages/socks/socks4/SOCKS4.protocol
129			*/
130			static const char *
131			socks4_strerror(int e)
132			{
133			switch (e) {
134			case 90:
135			return "Succeeded";
136			case 91:
137			return "Request rejected or failed";
138			case 92:
139			return "SOCKS server cannot connect to identd on the client";
140			case 93:
141			return "Client program and identd report different user-ids";
142			default:
143			return "Unknown error";
144			}
145			}
146
147			/*
148			* Error strings taken almost directly from RFC 1928.
149			*/
150			static const char *
151			socks5_strerror(int e)
152			{
153			switch (e) {
154			case 0:
155			return "Succeeded";
156			case 1:
157			return "General SOCKS server failure";
158			case 2:
159			return "Connection not allowed by ruleset";
160			case 3:
161			return "Network unreachable";
162			case 4:
163			return "Host unreachable";
164			case 5:
165			return "Connection refused";
166			case 6:
167			return "TTL expired";
168			case 7:
169			return "Command not supported";
170			case 8:
171			return "Address type not supported";
172			default:
173			return "Unknown error";
174			}
175			}
176
177			int
178			socks_connect(const char host, const char port,
179			struct addrinfo hints __attribute__ ((__unused__)),
180			const char proxyhost, const char proxyport, struct addrinfo proxyhints,
181			int socksv, const char *proxyuser)
182			{
183			int proxyfd, r, authretry = 0;
184			size_t hlen, wlen;
185			unsigned char buf[1024];
186			size_t cnt;
187			struct sockaddr_storage addr;
188			struct sockaddr_in in4 = (struct sockaddr_in )&addr;
189			struct sockaddr_in6 in6 = (struct sockaddr_in6 )&addr;
190			in_port_t serverport;
191			const char *proxypass = NULL;
192
193			if (proxyport == NULL)
194			proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT;
195
196			/* Abuse API to lookup port */
197			if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr,
198			sizeof(addr), 1, 1) == -1)
199			errx(1, "unknown port \"%.64s\"", port);
200			serverport = in4->sin_port;
201
202			again:
203			if (authretry++ > 3)
204			errx(1, "Too many authentication failures");
205
206			proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
207
208			if (proxyfd < 0)
209			return (-1);
210
211			if (socksv == 5) {
212			if (decode_addrport(host, port, (struct sockaddr *)&addr,
213			sizeof(addr), 0, 1) == -1)
214			addr.ss_family = 0; /* used in switch below */
215
216			/* Version 5, one method: no authentication */
217			buf[0] = SOCKS_V5;
218			buf[1] = 1;
219			buf[2] = SOCKS_NOAUTH;
220			cnt = atomicio(vwrite, proxyfd, buf, 3);
221			if (cnt != 3)
222			err(1, "write failed (%zu/3)", cnt);
223
224			cnt = atomicio(read, proxyfd, buf, 2);
225			if (cnt != 2)
226			err(1, "read failed (%zu/3)", cnt);
227
228			if (buf[1] == SOCKS_NOMETHOD)
229			errx(1, "authentication method negotiation failed");
230
231			switch (addr.ss_family) {
232			case 0:
233			/* Version 5, connect: domain name */
234
235			/* Max domain name length is 255 bytes */
236			hlen = strlen(host);
237			if (hlen > 255)
238			errx(1, "host name too long for SOCKS5");
239			buf[0] = SOCKS_V5;
240			buf[1] = SOCKS_CONNECT;
241			buf[2] = 0;
242			buf[3] = SOCKS_DOMAIN;
243			buf[4] = hlen;
244			memcpy(buf + 5, host, hlen);
245			memcpy(buf + 5 + hlen, &serverport, sizeof serverport);
246			wlen = 7 + hlen;
247			break;
248			case AF_INET:
249			/* Version 5, connect: IPv4 address */
250			buf[0] = SOCKS_V5;
251			buf[1] = SOCKS_CONNECT;
252			buf[2] = 0;
253			buf[3] = SOCKS_IPV4;
254			memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
255			memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port);
256			wlen = 10;
257			break;
258			case AF_INET6:
259			/* Version 5, connect: IPv6 address */
260			buf[0] = SOCKS_V5;
261			buf[1] = SOCKS_CONNECT;
262			buf[2] = 0;
263			buf[3] = SOCKS_IPV6;
264			memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr);
265			memcpy(buf + 20, &in6->sin6_port,
266			sizeof in6->sin6_port);
267			wlen = 22;
268			break;
269			default:
270			errx(1, "internal error: silly AF");
271			}
272
273			cnt = atomicio(vwrite, proxyfd, buf, wlen);
274			if (cnt != wlen)
275			err(1, "write failed (%zu/%zu)", cnt, wlen);
276
277			cnt = atomicio(read, proxyfd, buf, 4);
278			if (cnt != 4)
279			err(1, "read failed (%zu/4)", cnt);
280			if (buf[1] != 0) {
281			errx(1, "connection failed, SOCKSv5 error: %s",
282			socks5_strerror(buf[1]));
283			}
284			switch (buf[3]) {
285			case SOCKS_IPV4:
286			cnt = atomicio(read, proxyfd, buf + 4, 6);
287			if (cnt != 6)
288			err(1, "read failed (%zu/6)", cnt);
289			break;
290			case SOCKS_IPV6:
291			cnt = atomicio(read, proxyfd, buf + 4, 18);
292			if (cnt != 18)
293			err(1, "read failed (%zu/18)", cnt);
294			break;
295			default:
296			errx(1, "connection failed, unsupported address type");
297			}
298			} else if (socksv == 4) {
299			/* This will exit on lookup failure */
300			decode_addrport(host, port, (struct sockaddr *)&addr,
301			sizeof(addr), 1, 0);
302
303			/* Version 4 */
304			buf[0] = SOCKS_V4;
305			buf[1] = SOCKS_CONNECT; /* connect */
306			memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port);
307			memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr);
308			buf[8] = 0; /* empty username */
309			wlen = 9;
310
311			cnt = atomicio(vwrite, proxyfd, buf, wlen);
312			if (cnt != wlen)
313			err(1, "write failed (%zu/%zu)", cnt, wlen);
314
315			cnt = atomicio(read, proxyfd, buf, 8);
316			if (cnt != 8)
317			err(1, "read failed (%zu/8)", cnt);
318			if (buf[1] != 90) {
319			errx(1, "connection failed, SOCKSv4 error: %s",
320			socks4_strerror(buf[1]));
321			}
322			} else if (socksv == -1) {
323			/* HTTP proxy CONNECT */
324
325			/* Disallow bad chars in hostname */
326			if (strcspn(host, "\r\n\t []:") != strlen(host))
327			errx(1, "Invalid hostname");
328
329			/* Try to be sane about numeric IPv6 addresses */
330			if (strchr(host, ':') != NULL) {
331			r = snprintf(buf, sizeof(buf),
332			"CONNECT [%s]:%d HTTP/1.0\r\n",
333			host, ntohs(serverport));
334			} else {
335			r = snprintf(buf, sizeof(buf),
336			"CONNECT %s:%d HTTP/1.0\r\n",
337			host, ntohs(serverport));
338			}
339			if (r == -1 \|\| (size_t)r >= sizeof(buf))
340			errx(1, "hostname too long");
341			r = strlen(buf);
342
343			cnt = atomicio(vwrite, proxyfd, buf, r);
344			if (cnt != r)
345			err(1, "write failed (%zu/%d)", cnt, r);
346
347			if (authretry > 1) {
348			char resp[1024];
349
350			proxypass = getproxypass(proxyuser, proxyhost);
351			r = snprintf(buf, sizeof(buf), "%s:%s",
352			proxyuser, proxypass);
353			if (r == -1 \|\| (size_t)r >= sizeof(buf) \|\|
354			b64_ntop(buf, strlen(buf), resp,
355			sizeof(resp)) == -1)
356			errx(1, "Proxy username/password too long");
357			r = snprintf(buf, sizeof(buf), "Proxy-Authorization: "
358			"Basic %s\r\n", resp);
359			if (r == -1 \|\| (size_t)r >= sizeof(buf))
360			errx(1, "Proxy auth response too long");
361			r = strlen(buf);
362			if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r)
363			err(1, "write failed (%zu/%d)", cnt, r);
364			}
365
366			/* Terminate headers */
367			if ((cnt = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2)
368			err(1, "write failed (%zu/2)", cnt);
369
370			/* Read status reply */
371			proxy_read_line(proxyfd, buf, sizeof(buf));
372			if (proxyuser != NULL &&
373			strncmp(buf, "HTTP/1.0 407 ", 12) == 0) {
374			if (authretry > 1) {
375			fprintf(stderr, "Proxy authentication "
376			"failed\n");
377			}
378			close(proxyfd);
379			goto again;
380			} else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 &&
381			strncmp(buf, "HTTP/1.1 200 ", 12) != 0)
382			errx(1, "Proxy error: \"%s\"", buf);
383
384			/* Headers continue until we hit an empty line */
385			for (r = 0; r < HTTP_MAXHDRS; r++) {
386			proxy_read_line(proxyfd, buf, sizeof(buf));
387			if (*buf == '\0')
388			break;
389			}
390			if (*buf != '\0')
391			errx(1, "Too many proxy headers received");
392			} else
393			errx(1, "Unknown proxy protocol %d", socksv);
394
395			return (proxyfd);
396			}