Annotation of src/usr.bin/nc/socks.c, Revision 1.8
1.8 ! deraadt 1: /* $OpenBSD: socks.c,v 1.7 2003/06/03 20:49:29 deraadt Exp $ */
1.1 jakob 2:
3: /*
4: * Copyright (c) 1999 Niklas Hallqvist. All rights reserved.
5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27: #include <sys/types.h>
28: #include <sys/socket.h>
29: #include <netinet/in.h>
30: #include <arpa/inet.h>
31:
32: #include <err.h>
33: #include <netdb.h>
34: #include <stdio.h>
35: #include <stdlib.h>
36: #include <string.h>
37: #include <unistd.h>
38:
39: #define SOCKS_PORT "1080"
1.5 markus 40: #define SOCKS_V5 5
41: #define SOCKS_V4 4
1.1 jakob 42: #define SOCKS_NOAUTH 0
43: #define SOCKS_NOMETHOD 0xff
44: #define SOCKS_CONNECT 1
45: #define SOCKS_IPV4 1
46: #define SOCKS_MAXCMDSZ 10
1.4 ericj 47:
48: int remote_connect(char *, char *, struct addrinfo);
1.8 ! deraadt 49: int socks_connect(char *host, char *port, struct addrinfo hints,
! 50: char *proxyhost, char *proxyport, struct addrinfo proxyhints,
! 51: int socksv);
1.1 jakob 52:
53: static in_addr_t
1.8 ! deraadt 54: decode_addr(const char *s)
1.1 jakob 55: {
56: struct hostent *hp = gethostbyname (s);
57: struct in_addr retval;
58:
59: if (hp)
60: return *(in_addr_t *)hp->h_addr_list[0];
61: if (inet_aton (s, &retval))
62: return retval.s_addr;
63: errx (1, "cannot decode address \"%s\"", s);
64: }
65:
66: static in_port_t
1.8 ! deraadt 67: decode_port(const char *s)
1.1 jakob 68: {
69: struct servent *sp;
70: in_port_t port;
71: char *p;
72:
73: port = strtol (s, &p, 10);
74: if (s == p) {
75: sp = getservbyname (s, "tcp");
76: if (sp)
77: return sp->s_port;
78: }
79: if (*s != '\0' && *p == '\0')
80: return htons (port);
81: errx (1, "cannot decode port \"%s\"", s);
82: }
83:
84: int
1.8 ! deraadt 85: socks_connect(char *host, char *port, struct addrinfo hints,
1.5 markus 86: char *proxyhost, char *proxyport, struct addrinfo proxyhints,
87: int socksv)
1.1 jakob 88: {
89: int proxyfd;
90: unsigned char buf[SOCKS_MAXCMDSZ];
91: ssize_t cnt;
92: in_addr_t serveraddr;
93: in_port_t serverport;
94:
95: if (proxyport)
96: proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
97: else
98: proxyfd = remote_connect(proxyhost, SOCKS_PORT, proxyhints);
99:
1.6 stevesk 100: if (proxyfd < 0)
1.1 jakob 101: return -1;
102:
103: serveraddr = decode_addr (host);
104: serverport = decode_port (port);
105:
1.5 markus 106: if (socksv == 5) {
107: /* Version 5, one method: no authentication */
108: buf[0] = SOCKS_V5;
109: buf[1] = 1;
110: buf[2] = SOCKS_NOAUTH;
111: cnt = write (proxyfd, buf, 3);
112: if (cnt == -1)
113: err (1, "write failed");
114: if (cnt != 3)
115: errx (1, "short write, %d (expected 3)", cnt);
116:
117: read (proxyfd, buf, 2);
118: if (buf[1] == SOCKS_NOMETHOD)
119: errx (1, "authentication method negotiation failed");
120:
121: /* Version 5, connect: IPv4 address */
122: buf[0] = SOCKS_V5;
123: buf[1] = SOCKS_CONNECT;
124: buf[2] = 0;
125: buf[3] = SOCKS_IPV4;
126: memcpy (buf + 4, &serveraddr, sizeof serveraddr);
127: memcpy (buf + 8, &serverport, sizeof serverport);
128:
129: /* XXX Handle short writes better */
130: cnt = write (proxyfd, buf, 10);
131: if (cnt == -1)
132: err (1, "write failed");
133: if (cnt != 10)
134: errx (1, "short write, %d (expected 10)", cnt);
135:
136: /* XXX Handle short reads better */
137: cnt = read (proxyfd, buf, sizeof buf);
138: if (cnt == -1)
139: err (1, "read failed");
140: if (cnt != 10)
141: errx (1, "unexpected reply size %d (expected 10)", cnt);
142: if (buf[1] != 0)
143: errx (1, "connection failed, SOCKS error %d", buf[1]);
144: } else {
145: /* Version 4 */
146: buf[0] = SOCKS_V4;
147: buf[1] = SOCKS_CONNECT; /* connect */
148: memcpy (buf + 2, &serverport, sizeof serverport);
149: memcpy (buf + 4, &serveraddr, sizeof serveraddr);
150: buf[8] = 0; /* empty username */
151:
152: cnt = write (proxyfd, buf, 9);
153: if (cnt == -1)
154: err (1, "write failed");
155: if (cnt != 9)
156: errx (1, "short write, %d (expected 9)", cnt);
157:
158: /* XXX Handle short reads better */
159: cnt = read (proxyfd, buf, 8);
160: if (cnt == -1)
161: err (1, "read failed");
162: if (cnt != 8)
163: errx (1, "unexpected reply size %d (expected 8)", cnt);
164: if (buf[1] != 90)
165: errx (1, "connection failed, SOCKS error %d", buf[1]);
166: }
1.1 jakob 167:
168: return proxyfd;
169: }