summaryrefslogtreecommitdiff
path: root/libbb/xconnect.c
blob: d8c8d02d527c992c287ade0545225d358455a806 (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
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Connect to host at port using address resolution from getaddrinfo
 *
 * Licensed under GPLv2, see file LICENSE in this tarball for details.
 */

#include <sys/socket.h> /* netinet/in.h needs it */
#include <netinet/in.h>
#include <net/if.h>
#include <sys/un.h>
#include "libbb.h"

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

#ifdef SO_BINDTODEVICE
int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
{
	int r;
	struct ifreq ifr;
	strncpy_IFNAMSIZ(ifr.ifr_name, iface);
	/* NB: passing (iface, strlen(iface) + 1) does not work!
	 * (maybe it works on _some_ kernels, but not on 2.6.26)
	 * Actually, ifr_name is at offset 0, and in practice
	 * just giving char[IFNAMSIZ] instead of struct ifreq works too.
	 * But just in case it's not true on some obscure arch... */
	r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
	if (r)
		bb_perror_msg("can't bind to interface %s", iface);
	return r;
}
#else
int FAST_FUNC setsockopt_bindtodevice(int fd UNUSED_PARAM,
		const char *iface UNUSED_PARAM)
{
	bb_error_msg("SO_BINDTODEVICE is not supported on this system");
	return -1;
}
#endif

len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd)
{
	len_and_sockaddr lsa;
	len_and_sockaddr *lsa_ptr;

	lsa.len = LSA_SIZEOF_SA;
	if (getsockname(fd, &lsa.u.sa, &lsa.len) != 0)
		return NULL;

	lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len);
	if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */
		lsa_ptr->len = lsa.len;
		getsockname(fd, &lsa_ptr->u.sa, &lsa_ptr->len);
	} else {
		memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len);
	}
	return lsa_ptr;
}

void FAST_FUNC 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)",
				"can't connect to remote host",
				inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
		bb_perror_msg_and_die("can't 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 FAST_FUNC 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;
}


/* "New" networking API */


int FAST_FUNC 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 FAST_FUNC 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,
IF_FEATURE_IPV6(sa_family_t af,)
		int ai_flags)
{
IF_NOT_FEATURE_IPV6(sa_family_t af = AF_INET;)
	int rc;
	len_and_sockaddr *r;
	struct addrinfo *result = NULL;
	struct addrinfo *used_res;
	const char *org_host = host; /* only for error msg */
	const char *cp;
	struct addrinfo hint;

	if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) {
		struct sockaddr_un *sun;

		r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
		r->len = sizeof(struct sockaddr_un);
		r->u.sa.sa_family = AF_UNIX;
		sun = (struct sockaddr_un *)&r->u.sa;
		safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path));
		return r;
	}

	r = NULL;

	/* Ugly parsing of host:addr */
	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
		/* Even uglier parsing of [xx]:nn */
		host++;
		cp = strchr(host, ']');
		if (!cp || (cp[1] != ':' && cp[1] != '\0')) {
			/* Malformed: must be [xx]:nn or [xx] */
			bb_error_msg("bad address '%s'", org_host);
			if (ai_flags & DIE_ON_ERROR)
				xfunc_die();
			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) { /* points to ":" or "]:" */
		int sz = cp - host + 1;

		host = safe_strncpy(alloca(sz), host, sz);
		if (ENABLE_FEATURE_IPV6 && *cp != ':') {
			cp++; /* skip ']' */
			if (*cp == '\0') /* [xx] without port */
				goto skip;
		}
		cp++; /* skip ':' */
		port = bb_strtou(cp, NULL, 10);
		if (errno || (unsigned)port > 0xffff) {
			bb_error_msg("bad port spec '%s'", org_host);
			if (ai_flags & DIE_ON_ERROR)
				xfunc_die();
			return NULL;
		}
 skip: ;
	}

	/* Next two if blocks allow to skip getaddrinfo()
	 * in case host name is a numeric IP(v6) address.
	 * getaddrinfo() initializes DNS resolution machinery,
	 * scans network config and such - tens of syscalls.
	 */
	/* If we were not asked specifically for IPv6,
	 * check whether this is a numeric IPv4 */
	IF_FEATURE_IPV6(if(af != AF_INET6)) {
		struct in_addr in4;
		if (inet_aton(host, &in4) != 0) {
			r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in));
			r->len = sizeof(struct sockaddr_in);
			r->u.sa.sa_family = AF_INET;
			r->u.sin.sin_addr = in4;
			goto set_port;
		}
	}
#if ENABLE_FEATURE_IPV6
	/* If we were not asked specifically for IPv4,
	 * check whether this is a numeric IPv6 */
	if (af != AF_INET) {
		struct in6_addr in6;
		if (inet_pton(AF_INET6, host, &in6) > 0) {
			r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in6));
			r->len = sizeof(struct sockaddr_in6);
			r->u.sa.sa_family = AF_INET6;
			r->u.sin6.sin6_addr = in6;
			goto set_port;
		}
	}
#endif

	memset(&hint, 0 , sizeof(hint));
	hint.ai_family = af;
	/* 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(LSA_LEN_SIZE + used_res->ai_addrlen);
	r->len = used_res->ai_addrlen;
	memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);

 set_port:
	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* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af)
{
	return str2sockaddr(host, port, af, 0);
}

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

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

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

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

#undef xsocket_type
int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type)
{
	IF_NOT_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(LSA_LEN_SIZE + len);
	lsa->len = len;
	lsa->u.sa.sa_family = family;
	*lsap = lsa;
	return fd;
}

int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap)
{
	return xsocket_type(lsap, IF_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, IF_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 FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port)
{
	return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
}

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


int FAST_FUNC 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 FAST_FUNC 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* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags)
{
	char host[128];
	char serv[16];
	int rc;
	socklen_t salen;

	if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) {
		struct sockaddr_un *sun = (struct sockaddr_un *)sa;
		return xasprintf("local:%.*s",
				(int) sizeof(sun->sun_path),
				sun->sun_path);
	}

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

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

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

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