aboutsummaryrefslogtreecommitdiff
path: root/libbb/xconnect.c
blob: 03ae773294983826b56fa2616b0bb062ab003654 (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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Connect to host at port using address resolution from getaddrinfo
 *
 */

#include <netinet/in.h>
#include "libbb.h"

void setsockopt_reuseaddr(int fd)
{
	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1));
}
int setsockopt_broadcast(int fd)
{
	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
}

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("%s (%s)",
				"cannot connect to remote host",
				inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
		bb_perror_msg_and_die("cannot connect to remote host");
	}
}

/* Return 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 bb_lookup_port(const char *port, const char *protocol, unsigned default_port)
{
	unsigned port_nr = default_port;
	if (port) {
		int old_errno;

		/* 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;
		port_nr = bb_strtou(port, NULL, 10);
		if (errno || port_nr > 65535) {
			struct servent *tserv = getservbyname(port, protocol);
			port_nr = default_port;
			if (tserv)
				port_nr = ntohs(tserv->s_port);
		}
		errno = old_errno;
	}
	return (uint16_t)port_nr;
}


/* "Old" networking API - only IPv4 */

/*
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);
}


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;
}
*/

/* "New" networking API */


int get_nport(const struct sockaddr *sa)
{
#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET6) {
		return ((struct sockaddr_in6*)sa)->sin6_port;
	}
#endif
	if (sa->sa_family == AF_INET) {
		return ((struct sockaddr_in*)sa)->sin_port;
	}
	/* What? UNIX socket? IPX?? :) */
	return -1;
}

void set_nport(len_and_sockaddr *lsa, unsigned port)
{
#if ENABLE_FEATURE_IPV6
	if (lsa->u.sa.sa_family == AF_INET6) {
		lsa->u.sin6.sin6_port = port;
		return;
	}
#endif
	if (lsa->u.sa.sa_family == AF_INET) {
		lsa->u.sin.sin_port = port;
		return;
	}
	/* What? UNIX socket? IPX?? :) */
}

/* We hijack this constant to mean something else */
/* It doesn't hurt because we will remove this bit anyway */
#define DIE_ON_ERROR AI_CANONNAME

/* host: "1.2.3.4[:port]", "www.google.com[:port]"
 * port: if neither of above specifies port # */
static len_and_sockaddr* str2sockaddr(
		const char *host, int port,
USE_FEATURE_IPV6(sa_family_t af,)
		int ai_flags)
{
	int rc;
	len_and_sockaddr *r = NULL;
	struct addrinfo *result = NULL;
	struct addrinfo *used_res;
	const char *org_host = host; /* only for error msg */
	const char *cp;
	struct addrinfo hint;

	/* Ugly parsing of host:addr */
	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
		host++;
		cp = strchr(host, ']');
		if (!cp || cp[1] != ':') /* Malformed: must have [xx]:nn */
			bb_error_msg_and_die("bad address '%s'", org_host);
			//return r; /* return NULL */
	} else {
		cp = strrchr(host, ':');
		if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
			/* There is more than one ':' (e.g. "::1") */
			cp = NULL; /* it's not a port spec */
		}
	}
	if (cp) {
		int sz = cp - host + 1;
		host = safe_strncpy(alloca(sz), host, sz);
		if (ENABLE_FEATURE_IPV6 && *cp != ':')
			cp++; /* skip ']' */
		cp++; /* skip ':' */
		port = xatou16(cp);
	}

	memset(&hint, 0 , sizeof(hint));
#if !ENABLE_FEATURE_IPV6
	hint.ai_family = AF_INET; /* do not try to find IPv6 */
#else
	hint.ai_family = af;
#endif
	/* Needed. Or else we will get each address thrice (or more)
	 * for each possible socket type (tcp,udp,raw...): */
	hint.ai_socktype = SOCK_STREAM;
	hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
	rc = getaddrinfo(host, NULL, &hint, &result);
	if (rc || !result) {
		bb_error_msg("bad address '%s'", org_host);
		if (ai_flags & DIE_ON_ERROR)
			xfunc_die();
		goto ret;
	}
	used_res = result;
#if ENABLE_FEATURE_PREFER_IPV4_ADDRESS
	while (1) {
		if (used_res->ai_family == AF_INET)
			break;
		used_res = used_res->ai_next;
		if (!used_res) {
			used_res = result;
			break;
		}
	}
#endif
	r = xmalloc(offsetof(len_and_sockaddr, u.sa) + used_res->ai_addrlen);
	r->len = used_res->ai_addrlen;
	memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);
	set_nport(r, htons(port));
 ret:
	freeaddrinfo(result);
	return r;
}
#if !ENABLE_FEATURE_IPV6
#define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags)
#endif

#if ENABLE_FEATURE_IPV6
len_and_sockaddr* host_and_af2sockaddr(const char *host, int port, sa_family_t af)
{
	return str2sockaddr(host, port, af, 0);
}

len_and_sockaddr* xhost_and_af2sockaddr(const char *host, int port, sa_family_t af)
{
	return str2sockaddr(host, port, af, DIE_ON_ERROR);
}
#endif

len_and_sockaddr* host2sockaddr(const char *host, int port)
{
	return str2sockaddr(host, port, AF_UNSPEC, 0);
}

len_and_sockaddr* xhost2sockaddr(const char *host, int port)
{
	return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR);
}

len_and_sockaddr* xdotted2sockaddr(const char *host, int port)
{
	return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR);
}

int xsocket_type(len_and_sockaddr **lsap, USE_FEATURE_IPV6(int family,) int sock_type)
{
	SKIP_FEATURE_IPV6(enum { family = AF_INET };)
	len_and_sockaddr *lsa;
	int fd;
	int len;

#if ENABLE_FEATURE_IPV6
	if (family == AF_UNSPEC) {
		fd = socket(AF_INET6, sock_type, 0);
		if (fd >= 0) {
			family = AF_INET6;
			goto done;
		}
		family = AF_INET;
	}
#endif
	fd = xsocket(family, sock_type, 0);
	len = sizeof(struct sockaddr_in);
#if ENABLE_FEATURE_IPV6
	if (family == AF_INET6) {
 done:
		len = sizeof(struct sockaddr_in6);
	}
#endif
	lsa = xzalloc(offsetof(len_and_sockaddr, u.sa) + len);
	lsa->len = len;
	lsa->u.sa.sa_family = family;
	*lsap = lsa;
	return fd;
}

int xsocket_stream(len_and_sockaddr **lsap)
{
	return xsocket_type(lsap, USE_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM);
}

static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type)
{
	int fd;
	len_and_sockaddr *lsa;

	if (bindaddr && bindaddr[0]) {
		lsa = xdotted2sockaddr(bindaddr, port);
		/* user specified bind addr dictates family */
		fd = xsocket(lsa->u.sa.sa_family, sock_type, 0);
	} else {
		fd = xsocket_type(&lsa, USE_FEATURE_IPV6(AF_UNSPEC,) sock_type);
		set_nport(lsa, htons(port));
	}
	setsockopt_reuseaddr(fd);
	xbind(fd, &lsa->u.sa, lsa->len);
	free(lsa);
	return fd;
}

int create_and_bind_stream_or_die(const char *bindaddr, int port)
{
	return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
}

int create_and_bind_dgram_or_die(const char *bindaddr, int port)
{
	return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM);
}


int create_and_connect_stream_or_die(const char *peer, int port)
{
	int fd;
	len_and_sockaddr *lsa;

	lsa = xhost2sockaddr(peer, port);
	fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
	setsockopt_reuseaddr(fd);
	xconnect(fd, &lsa->u.sa, lsa->len);
	free(lsa);
	return fd;
}

int xconnect_stream(const len_and_sockaddr *lsa)
{
	int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
	xconnect(fd, &lsa->u.sa, lsa->len);
	return fd;
}

/* We hijack this constant to mean something else */
/* It doesn't hurt because we will add this bit anyway */
#define IGNORE_PORT NI_NUMERICSERV
static char* sockaddr2str(const struct sockaddr *sa, int flags)
{
	char host[128];
	char serv[16];
	int rc;
	socklen_t salen;

	salen = LSA_SIZEOF_SA;
#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET)
		salen = sizeof(struct sockaddr_in);
	if (sa->sa_family == AF_INET6)
		salen = sizeof(struct sockaddr_in6);
#endif
	rc = getnameinfo(sa, salen,
			host, sizeof(host),
	/* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
			serv, sizeof(serv),
			/* do not resolve port# into service _name_ */
			flags | NI_NUMERICSERV
	);
	if (rc)
		return NULL;
	if (flags & IGNORE_PORT)
		return xstrdup(host);
#if ENABLE_FEATURE_IPV6
	if (sa->sa_family == AF_INET6) {
		if (strchr(host, ':')) /* heh, it's not a resolved hostname */
			return xasprintf("[%s]:%s", host, serv);
		/*return xasprintf("%s:%s", host, serv);*/
		/* - fall through instead */
	}
#endif
	/* For now we don't support anything else, so it has to be INET */
	/*if (sa->sa_family == AF_INET)*/
		return xasprintf("%s:%s", host, serv);
	/*return xstrdup(host);*/
}

char* xmalloc_sockaddr2host(const struct sockaddr *sa)
{
	return sockaddr2str(sa, 0);
}

char* xmalloc_sockaddr2host_noport(const struct sockaddr *sa)
{
	return sockaddr2str(sa, IGNORE_PORT);
}

char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa)
{
	return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT);
}
char* xmalloc_sockaddr2dotted(const struct sockaddr *sa)
{
	return sockaddr2str(sa, NI_NUMERICHOST);
}

char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa)
{
	return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT);
}