aboutsummaryrefslogtreecommitdiff
path: root/libbb/xconnect.c
blob: cf1f9d59acf27fd7aa81bce93c29e9b3100c9463 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Connect to host at port using address resolution from getaddrinfo
 *
 */

#include "libbb.h"

/* Return network byte ordered port number for a service.
 * If "port" is a number use it as the port.
 * If "port" is a name it is looked up in /etc/services, if it isnt found return
 * default_port
 */
unsigned short bb_lookup_port(const char *port, const char *protocol, unsigned short default_port)
{
	unsigned short port_nr = htons(default_port);
	if (port) {
		char *endptr;
		int old_errno;
		long port_long;

		/* Since this is a lib function, we're not allowed to reset errno to 0.
		 * Doing so could break an app that is deferring checking of errno. */
		old_errno = errno;
		errno = 0;
		port_long = strtol(port, &endptr, 10);
		if (errno != 0 || *endptr!='\0' || endptr==port || port_long < 0 || port_long > 65535) {
			struct servent *tserv = getservbyname(port, protocol);
			if (tserv) {
				port_nr = tserv->s_port;
			}
		} else {
			port_nr = htons(port_long);
		}
		errno = old_errno;
	}
	return port_nr;
}

void bb_lookup_host(struct sockaddr_in *s_in, const char *host)
{
	struct hostent *he;

	memset(s_in, 0, sizeof(struct sockaddr_in));
	s_in->sin_family = AF_INET;
	he = xgethostbyname(host);
	memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
}

void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
{
	if (connect(s, s_addr, addrlen) < 0) {
		if (ENABLE_FEATURE_CLEAN_UP) close(s);
		if (s_addr->sa_family == AF_INET)
			bb_perror_msg_and_die("cannot connect to remote host (%s)",
				inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
		bb_perror_msg_and_die("cannot connect to remote host");
	}
}

int xconnect_tcp_v4(struct sockaddr_in *s_addr)
{
	int s = xsocket(AF_INET, SOCK_STREAM, 0);
	xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr));
	return s;
}

int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen)
{
	union {
		struct in_addr a4;
#if ENABLE_FEATURE_IPV6
		struct in6_addr a6;
#endif
	} a;

	/* TODO maybe: port spec? like n.n.n.n:nn */

#if ENABLE_FEATURE_IPV6
	if (socklen >= sizeof(struct sockaddr_in6)
	 && inet_pton(AF_INET6, dotted, &a.a6) > 0
	) {
		((struct sockaddr_in6*)sp)->sin6_family = AF_INET6;
		((struct sockaddr_in6*)sp)->sin6_addr = a.a6;
		/* ((struct sockaddr_in6*)sp)->sin6_port = */
		return 0; /* success */
	}
#endif
	if (socklen >= sizeof(struct sockaddr_in)
	 && inet_pton(AF_INET, dotted, &a.a4) > 0
	) {
		((struct sockaddr_in*)sp)->sin_family = AF_INET;
		((struct sockaddr_in*)sp)->sin_addr = a.a4;
		/* ((struct sockaddr_in*)sp)->sin_port = */
		return 0; /* success */
	}
	return 1;
}

int xsocket_stream_ip4or6(sa_family_t *fp)
{
	int fd;
#if ENABLE_FEATURE_IPV6
	fd = socket(AF_INET6, SOCK_STREAM, 0);
	if (fp) *fp = AF_INET6;
	if (fd < 0)
#endif
	{
		fd = xsocket(AF_INET, SOCK_STREAM, 0);
		if (fp) *fp = AF_INET;
	}
	return fd;
}

int create_and_bind_socket_ip4or6(const char *hostaddr, int port)
{
	static const int on = 1;
	int fd;
	sockaddr_inet sa;

	memset(&sa, 0, sizeof(sa));
	if (hostaddr && dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa)))
		bb_show_usage();

	if (!sa.sa.sa_family)
		fd = xsocket_stream_ip4or6(&sa.sa.sa_family);
	else /* user specified bind addr dictates family */
		fd = xsocket(sa.sa.sa_family, SOCK_STREAM, 0);
	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

	/* if (port >= 0) { */
#if ENABLE_FEATURE_IPV6
		if (sa.sa.sa_family == AF_INET6 /* && !sa.sin6.sin6_port */)
			sa.sin6.sin6_port = htons(port);
#endif
		if (sa.sa.sa_family == AF_INET /* && !sa.sin.sin_port */)
			sa.sin.sin_port = htons(port);
	/* } */

	xbind(fd, &sa.sa, sizeof(sa));
	return fd;
}

int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen)
{
	union {
		struct in_addr a4;
#if ENABLE_FEATURE_IPV6
		struct in6_addr a6;
#endif
	} a;

	/* TODO maybe: port spec? like n.n.n.n:nn */

#if ENABLE_FEATURE_IPV6
	if (socklen >= sizeof(struct sockaddr_in6)
	 && inet_pton(AF_INET6, dotted, &a.a6) > 0
	) {
		((struct sockaddr_in6*)sp)->sin6_family = AF_INET6;
		((struct sockaddr_in6*)sp)->sin6_addr = a.a6;
		/* ((struct sockaddr_in6*)sp)->sin6_port = */
		return 0; /* success */
	}
#endif
	if (socklen >= sizeof(struct sockaddr_in)
	 && inet_pton(AF_INET, dotted, &a.a4) > 0
	) {
		((struct sockaddr_in*)sp)->sin_family = AF_INET;
		((struct sockaddr_in*)sp)->sin_addr = a.a4;
		/* ((struct sockaddr_in*)sp)->sin_port = */
		return 0; /* success */
	}
	return 1;
}

int xsocket_stream_ip4or6(sa_family_t *fp)
{
	int fd;
#if ENABLE_FEATURE_IPV6
	fd = socket(AF_INET6, SOCK_STREAM, 0);
	if (fp) *fp = AF_INET6;
	if (fd < 0)
#endif
	{
		fd = xsocket(AF_INET, SOCK_STREAM, 0);
		if (fp) *fp = AF_INET;
	}
	return fd;
}

int create_and_bind_socket_ip4or6(const char *hostaddr, int port)
{
	static const int on = 1;
	int fd;
	sockaddr_inet sa;

	memset(&sa, 0, sizeof(sa));
	if (hostaddr) {
		if (dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa)))
			bb_error_msg_and_die("bad address '%s'", hostaddr);
		/* user specified bind addr dictates family */
		fd = xsocket(sa.sa.sa_family, SOCK_STREAM, 0);
	} else 
		fd = xsocket_stream_ip4or6(&sa.sa.sa_family);
	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));

	/* if (port >= 0) { */
#if ENABLE_FEATURE_IPV6
		if (sa.sa.sa_family == AF_INET6 /* && !sa.sin6.sin6_port */)
			sa.sin6.sin6_port = htons(port);
#endif
		if (sa.sa.sa_family == AF_INET /* && !sa.sin.sin_port */)
			sa.sin.sin_port = htons(port);
	/* } */

	xbind(fd, &sa.sa, sizeof(sa));
	return fd;
}