busybox/libbb/xconnect.c

/* 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"

static const int one = 1;
int setsockopt_reuseaddr(int fd)
{
	return setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
}
int setsockopt_broadcast(int fd)
{
	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
}

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(len_and_sockaddr *lsa)
{
#if ENABLE_FEATURE_IPV6
	if (lsa->sa.sa_family == AF_INET6) {
		return lsa->sin6.sin6_port;
	}
#endif
	if (lsa->sa.sa_family == AF_INET) {
		return lsa->sin.sin_port;
	}
	return -1;
	/* What? UNIX socket? IPX?? :) */
}

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

/* peer: "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, int ai_flags)
{
	int rc;
	len_and_sockaddr *r; // = NULL;
	struct addrinfo *result = NULL;
	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));
	/* hint.ai_family = AF_UNSPEC; - zero anyway */
#if !ENABLE_FEATURE_IPV6
	hint.ai_family = AF_INET; /* do not try to find IPv6 */
#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;
	rc = getaddrinfo(host, NULL, &hint, &result);
	if (rc || !result)
		bb_error_msg_and_die("bad address '%s'", org_host);
	r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
	r->len = result->ai_addrlen;
	memcpy(&r->sa, result->ai_addr, result->ai_addrlen);
	set_nport(r, htons(port));
	freeaddrinfo(result);
	return r;
}

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

static len_and_sockaddr* dotted2sockaddr(const char *host, int port)
{
	return str2sockaddr(host, port, NI_NUMERICHOST);
}

int xsocket_stream(len_and_sockaddr **lsap)
{
	len_and_sockaddr *lsa;
	int fd;
	int len = sizeof(struct sockaddr_in);
	int family = AF_INET;

#if ENABLE_FEATURE_IPV6
	fd = socket(AF_INET6, SOCK_STREAM, 0);
	if (fd >= 0) {
		len = sizeof(struct sockaddr_in6);
		family = AF_INET6;
	} else
#endif
	{
		fd = xsocket(AF_INET, SOCK_STREAM, 0);
	}
	lsa = xzalloc(offsetof(len_and_sockaddr, sa) + len);
	lsa->len = len;
	lsa->sa.sa_family = family;
	*lsap = lsa;
	return fd;
}

int create_and_bind_stream_or_die(const char *bindaddr, int port)
{
	int fd;
	len_and_sockaddr *lsa;

	if (bindaddr && bindaddr[0]) {
		lsa = dotted2sockaddr(bindaddr, port);
		/* currently NULL check is in str2sockaddr */
		//if (!lsa)
		//	bb_error_msg_and_die("bad address '%s'", bindaddr);
		/* user specified bind addr dictates family */
		fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
	} else {
		fd = xsocket_stream(&lsa);
		set_nport(lsa, htons(port));
	}
	setsockopt_reuseaddr(fd);
	xbind(fd, &lsa->sa, lsa->len);
	free(lsa);
	return fd;
}

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

	lsa = host2sockaddr(peer, port);
	/* currently NULL check is in str2sockaddr */
	//if (!lsa)
	//	bb_error_msg_and_die("bad address '%s'", peer);
	fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
	setsockopt_reuseaddr(fd);
	xconnect(fd, &lsa->sa, lsa->len);
	free(lsa);
	return fd;
}

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

static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags)
{
	char host[128];
	char serv[16];
	int rc = getnameinfo(sa, salen,
			host, sizeof(host),
			serv, sizeof(serv),
			flags | NI_NUMERICSERV /* do not resolve port# */
	);
	if (rc) return NULL;
// We probably need to use [%s]:%s for IPv6...
	return xasprintf("%s:%s", host, serv);
}

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

char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen)
{
	return sockaddr2str(sa, salen, NI_NUMERICHOST);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Utility routines.
4	*
5	* Connect to host at port using address resolution from getaddrinfo
6	*
7	*/
8
9	#include <netinet/in.h>
10	#include "libbb.h"
11
12	static const int one = 1;
13	int setsockopt_reuseaddr(int fd)
14	{
15	return setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
16	}
17	int setsockopt_broadcast(int fd)
18	{
19	return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one));
20	}
21
22	void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
23	{
24	if (connect(s, s_addr, addrlen) < 0) {
25	if (ENABLE_FEATURE_CLEAN_UP)
26	close(s);
27	if (s_addr->sa_family == AF_INET)
28	bb_perror_msg_and_die("%s (%s)",
29	"cannot connect to remote host",
30	inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
31	bb_perror_msg_and_die("cannot connect to remote host");
32	}
33	}
34
35	/* Return port number for a service.
36	* If "port" is a number use it as the port.
37	* If "port" is a name it is looked up in /etc/services, if it isnt found return
38	* default_port */
39	unsigned bb_lookup_port(const char port, const char protocol, unsigned default_port)
40	{
41	unsigned port_nr = default_port;
42	if (port) {
43	int old_errno;
44
45	/* Since this is a lib function, we're not allowed to reset errno to 0.
46	* Doing so could break an app that is deferring checking of errno. */
47	old_errno = errno;
48	port_nr = bb_strtou(port, NULL, 10);
49	if (errno \|\| port_nr > 65535) {
50	struct servent *tserv = getservbyname(port, protocol);
51	port_nr = default_port;
52	if (tserv)
53	port_nr = ntohs(tserv->s_port);
54	}
55	errno = old_errno;
56	}
57	return (uint16_t)port_nr;
58	}
59
60
61	/* "Old" networking API - only IPv4 */
62
63
64	void bb_lookup_host(struct sockaddr_in s_in, const char host)
65	{
66	struct hostent *he;
67
68	memset(s_in, 0, sizeof(struct sockaddr_in));
69	s_in->sin_family = AF_INET;
70	he = xgethostbyname(host);
71	memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
72	}
73
74	int xconnect_tcp_v4(struct sockaddr_in *s_addr)
75	{
76	int s = xsocket(AF_INET, SOCK_STREAM, 0);
77	xconnect(s, (struct sockaddr) s_addr, sizeof(s_addr));
78	return s;
79	}
80
81
82	/* "New" networking API */
83
84
85	int get_nport(len_and_sockaddr *lsa)
86	{
87	#if ENABLE_FEATURE_IPV6
88	if (lsa->sa.sa_family == AF_INET6) {
89	return lsa->sin6.sin6_port;
90	}
91	#endif
92	if (lsa->sa.sa_family == AF_INET) {
93	return lsa->sin.sin_port;
94	}
95	return -1;
96	/* What? UNIX socket? IPX?? :) */
97	}
98
99	void set_nport(len_and_sockaddr *lsa, unsigned port)
100	{
101	#if ENABLE_FEATURE_IPV6
102	if (lsa->sa.sa_family == AF_INET6) {
103	lsa->sin6.sin6_port = port;
104	return;
105	}
106	#endif
107	if (lsa->sa.sa_family == AF_INET) {
108	lsa->sin.sin_port = port;
109	return;
110	}
111	/* What? UNIX socket? IPX?? :) */
112	}
113
114	/* peer: "1.2.3.4[:port]", "www.google.com[:port]"
115	* port: if neither of above specifies port #
116	*/
117	static len_and_sockaddr* str2sockaddr(const char *host, int port, int ai_flags)
118	{
119	int rc;
120	len_and_sockaddr *r; // = NULL;
121	struct addrinfo *result = NULL;
122	const char org_host = host; / only for error msg */
123	const char *cp;
124	struct addrinfo hint;
125
126	/* Ugly parsing of host:addr */
127	if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
128	host++;
129	cp = strchr(host, ']');
130	if (!cp \|\| cp[1] != ':') /* Malformed: must have [xx]:nn */
131	bb_error_msg_and_die("bad address '%s'", org_host);
132	//return r; /* return NULL */
133	} else {
134	cp = strrchr(host, ':');
135	if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
136	/* There is more than one ':' (e.g. "::1") */
137	cp = NULL; /* it's not a port spec */
138	}
139	}
140	if (cp) {
141	int sz = cp - host + 1;
142	host = safe_strncpy(alloca(sz), host, sz);
143	if (ENABLE_FEATURE_IPV6 && *cp != ':')
144	cp++; /* skip ']' */
145	cp++; /* skip ':' */
146	port = xatou16(cp);
147	}
148
149	memset(&hint, 0 , sizeof(hint));
150	/* hint.ai_family = AF_UNSPEC; - zero anyway */
151	#if !ENABLE_FEATURE_IPV6
152	hint.ai_family = AF_INET; /* do not try to find IPv6 */
153	#endif
154	/* Needed. Or else we will get each address thrice (or more)
155	* for each possible socket type (tcp,udp,raw...): */
156	hint.ai_socktype = SOCK_STREAM;
157	hint.ai_flags = ai_flags;
158	rc = getaddrinfo(host, NULL, &hint, &result);
159	if (rc \|\| !result)
160	bb_error_msg_and_die("bad address '%s'", org_host);
161	r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
162	r->len = result->ai_addrlen;
163	memcpy(&r->sa, result->ai_addr, result->ai_addrlen);
164	set_nport(r, htons(port));
165	freeaddrinfo(result);
166	return r;
167	}
168
169	len_and_sockaddr* host2sockaddr(const char *host, int port)
170	{
171	return str2sockaddr(host, port, 0);
172	}
173
174	static len_and_sockaddr* dotted2sockaddr(const char *host, int port)
175	{
176	return str2sockaddr(host, port, NI_NUMERICHOST);
177	}
178
179	int xsocket_stream(len_and_sockaddr **lsap)
180	{
181	len_and_sockaddr *lsa;
182	int fd;
183	int len = sizeof(struct sockaddr_in);
184	int family = AF_INET;
185
186	#if ENABLE_FEATURE_IPV6
187	fd = socket(AF_INET6, SOCK_STREAM, 0);
188	if (fd >= 0) {
189	len = sizeof(struct sockaddr_in6);
190	family = AF_INET6;
191	} else
192	#endif
193	{
194	fd = xsocket(AF_INET, SOCK_STREAM, 0);
195	}
196	lsa = xzalloc(offsetof(len_and_sockaddr, sa) + len);
197	lsa->len = len;
198	lsa->sa.sa_family = family;
199	*lsap = lsa;
200	return fd;
201	}
202
203	int create_and_bind_stream_or_die(const char *bindaddr, int port)
204	{
205	int fd;
206	len_and_sockaddr *lsa;
207
208	if (bindaddr && bindaddr[0]) {
209	lsa = dotted2sockaddr(bindaddr, port);
210	/* currently NULL check is in str2sockaddr */
211	//if (!lsa)
212	// bb_error_msg_and_die("bad address '%s'", bindaddr);
213	/* user specified bind addr dictates family */
214	fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
215	} else {
216	fd = xsocket_stream(&lsa);
217	set_nport(lsa, htons(port));
218	}
219	setsockopt_reuseaddr(fd);
220	xbind(fd, &lsa->sa, lsa->len);
221	free(lsa);
222	return fd;
223	}
224
225	int create_and_connect_stream_or_die(const char *peer, int port)
226	{
227	int fd;
228	len_and_sockaddr *lsa;
229
230	lsa = host2sockaddr(peer, port);
231	/* currently NULL check is in str2sockaddr */
232	//if (!lsa)
233	// bb_error_msg_and_die("bad address '%s'", peer);
234	fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
235	setsockopt_reuseaddr(fd);
236	xconnect(fd, &lsa->sa, lsa->len);
237	free(lsa);
238	return fd;
239	}
240
241	int xconnect_stream(const len_and_sockaddr *lsa)
242	{
243	int fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
244	xconnect(fd, &lsa->sa, lsa->len);
245	return fd;
246	}
247
248	static char* sockaddr2str(const struct sockaddr *sa, socklen_t salen, int flags)
249	{
250	char host[128];
251	char serv[16];
252	int rc = getnameinfo(sa, salen,
253	host, sizeof(host),
254	serv, sizeof(serv),
255	flags \| NI_NUMERICSERV /* do not resolve port# */
256	);
257	if (rc) return NULL;
258	// We probably need to use [%s]:%s for IPv6...
259	return xasprintf("%s:%s", host, serv);
260	}
261
262	char* xmalloc_sockaddr2host(const struct sockaddr *sa, socklen_t salen)
263	{
264	return sockaddr2str(sa, salen, 0);
265	}
266
267	char* xmalloc_sockaddr2dotted(const struct sockaddr *sa, socklen_t salen)
268	{
269	return sockaddr2str(sa, salen, NI_NUMERICHOST);
270	}