libbb/xconnect.c - busybox - Git at Google

 /* 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);
 }
	/* 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);
	}