/* -*- c-file-style: "linux" -*-      rsync -- fast file replication program      Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>   Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>      This program is free software; you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation; either version 2 of the License, or   (at your option) any later version.      This program is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.      You should have received a copy of the GNU General Public License   along with this program; if not, write to the Free Software   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.*/ /** * @file socket.c *  * Socket functions used in rsync. * * This file is now converted to use the new-style getaddrinfo() * interface, which supports IPv6 but is also supported on recent * IPv4-only machines.  On systems that don't have that interface, we * emulate it using the KAME implementation. **/ #include "rsync.h"  /* Establish a proxy connection on an open socket to a web roxy by * using the CONNECT method. */static int establish_proxy_connection(int fd, char *host, int port){	char buffer[1024];	char *cp; 	snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);	if (write(fd, buffer, strlen(buffer)) != (int) strlen(buffer)) {		rprintf(FERROR, "failed to write to proxy: %s\n",			strerror(errno));		return -1;	} 	for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) {		if (read(fd, cp, 1) != 1) {			rprintf(FERROR, "failed to read from proxy: %s\n",				strerror(errno));			return -1;		}		if (*cp == '\n')			break;	} 	if (*cp != '\n')		cp++;	*cp-- = '\0';	if (*cp == '\r')		*cp = '\0';	if (strncmp(buffer, "HTTP/", 5) != 0) {		rprintf(FERROR, "bad response from proxy - %s\n",			buffer);		return -1;	}	for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++)		;	while (*cp == ' ')		cp++;	if (*cp != '2') {		rprintf(FERROR, "bad response from proxy - %s\n",			buffer);		return -1;	}	/* throw away the rest of the HTTP header */	while (1) {		for (cp = buffer; cp < &buffer[sizeof(buffer) - 1];		     cp++) {			if (read(fd, cp, 1) != 1) {				rprintf(FERROR, "failed to read from proxy: %s\n",					strerror(errno));				return -1;			}			if (*cp == '\n')				break;		}		if ((cp > buffer) && (*cp == '\n'))			cp--;		if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))			break;	}	return 0;}  /** * Try to set the local address for a newly-created socket.  Return -1 * if this fails. **/int try_bind_local(int s,		   int ai_family, int ai_socktype,		   const char *bind_address){	int error;	struct addrinfo bhints, *bres_all, *r; 	memset(&bhints, 0, sizeof(bhints));	bhints.ai_family = ai_family;	bhints.ai_socktype = ai_socktype;	bhints.ai_flags = AI_PASSIVE;	if ((error = getaddrinfo(bind_address, NULL, &bhints, &bres_all))) {		rprintf(FERROR, RSYNC_NAME ": getaddrinfo %s: %s\n",			bind_address, gai_strerror(error));		return -1;	} 	for (r = bres_all; r; r = r->ai_next) {		if (bind(s, r->ai_addr, r->ai_addrlen) == -1)			continue;		return s;	} 	/* no error message; there might be some problem that allows	 * creation of the socket but not binding, perhaps if the	 * machine has no ipv6 address of this name. */	return -1;}  /** * Open a socket to a tcp remote host with the specified port . * * Based on code from Warren.  Proxy support by Stephen Rothwell. * getaddrinfo() rewrite contributed by KAME.net. * * Now that we support IPv6 we need to look up the remote machine's * address first, using @p af_hint to set a preference for the type * of address.  Then depending on whether it has v4 or v6 addresses we * try to open a connection. * * The loop allows for machines with some addresses which may not be * reachable, perhaps because we can't e.g. route ipv6 to that network * but we can get ip4 packets through. * * @param bind_address Local address to use.  Normally NULL to bind * the wildcard address. * * @param af_hint Address family, e.g. AF_INET or AF_INET6. **/int open_socket_out(char *host, int port, const char *bind_address,		    int af_hint){	int type = SOCK_STREAM;	int error;	int s;	struct addrinfo hints, *res0, *res;	char portbuf[10];	char *h;	int proxied = 0;	char buffer[1024];	char *cp; 	/* if we have a RSYNC_PROXY env variable then redirect our	 * connetcion via a web proxy at the given address. The format	 * is hostname:port */	h = getenv("RSYNC_PROXY");	proxied = (h != NULL) && (*h != '\0'); 	if (proxied) {		strlcpy(buffer, h, sizeof(buffer));		cp = strchr(buffer, ':');		if (cp == NULL) {			rprintf(FERROR,				"invalid proxy specification: should be HOST:PORT\n");			return -1;		}		*cp++ = '\0';		strcpy(portbuf, cp);		h = buffer;	} else {		snprintf(portbuf, sizeof(portbuf), "%d", port);		h = host;	} 	memset(&hints, 0, sizeof(hints));	hints.ai_family = af_hint;	hints.ai_socktype = type;	error = getaddrinfo(h, portbuf, &hints, &res0);	if (error) {		rprintf(FERROR, RSYNC_NAME ": getaddrinfo: %s %s: %s\n",			h, portbuf, gai_strerror(error));		return -1;	} 	s = -1;	/* Try to connect to all addresses for this machine until we get	 * through.  It might e.g. be multi-homed, or have both IPv4 and IPv6	 * addresses.  We need to create a socket for each record, since the	 * address record tells us what protocol to use to try to connect. */	for (res = res0; res; res = res->ai_next) {		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);		if (s < 0)			continue; 		if (bind_address)			if (try_bind_local(s, res->ai_family, type,					   bind_address) == -1) {				close(s);				s = -1;				continue;			} 		if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {			close(s);			s = -1;			continue;		}		if (proxied &&		    establish_proxy_connection(s, host, port) != 0) {			close(s);			s = -1;			continue;		} else			break;	}	freeaddrinfo(res0);	if (s < 0) {		rprintf(FERROR, RSYNC_NAME ": failed to connect to %s: %s\n",			h, strerror(errno));		return -1;	}	return s;}  /** * Open an outgoing socket, but allow for it to be intercepted by * $RSYNC_CONNECT_PROG, which will execute a program across a TCP * socketpair rather than really opening a socket. * * We use this primarily in testing to detect TCP flow bugs, but not * cause security problems by really opening remote connections. * * This is based on the Samba LIBSMB_PROG feature. * * @param bind_address Local address to use.  Normally NULL to get the stack default. **/int open_socket_out_wrapped (char *host,			     int port,			     const char *bind_address,			     int af_hint){	char *prog; 	if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL) 		return sock_exec (prog);	else 		return open_socket_out (host, port, bind_address,					af_hint);}   /** * Open a socket of the specified type, port and address for incoming data * * Try to be better about handling the results of getaddrinfo(): when * opening an inbound socket, we might get several address results, * e.g. for the machine's ipv4 and ipv6 name.   *  * If binding a wildcard, then any one of them should do.  If an address * was specified but it's insufficiently specific then that's not our * fault.   *  * However, some of the advertized addresses may not work because e.g. we * don't have IPv6 support in the kernel.  In that case go on and try all * addresses until one succeeds. *  * @param bind_address Local address to bind, or NULL to allow it to * default. **/static int open_socket_in(int type, int port, const char *bind_address,			  int af_hint){	int one=1;	int s;	struct addrinfo hints, *all_ai, *resp;	char portbuf[10];	int error; 	memset(&hints, 0, sizeof(hints));	hints.ai_family = af_hint;	hints.ai_socktype = type;	hints.ai_flags = AI_PASSIVE;	snprintf(portbuf, sizeof(portbuf), "%d", port);	error = getaddrinfo(bind_address, portbuf, &hints, &all_ai);	if (error) {		rprintf(FERROR, RSYNC_NAME ": getaddrinfo: bind address %s: %s\n",			bind_address, gai_strerror(error));		return -1;	} 	/* We may not be able to create the socket, if for example the	 * machine knows about IPv6 in the C library, but not in the	 * kernel. */	for (resp = all_ai; resp; resp = resp->ai_next) {		s = socket(resp->ai_family, resp->ai_socktype,			   resp->ai_protocol); 		if (s == -1) 			/* See if there's another address that will work... */			continue;				setsockopt(s, SOL_SOCKET, SO_REUSEADDR,			   (char *)&one, sizeof one);				/* now we've got a socket - we need to bind it */		if (bind(s, all_ai->ai_addr, all_ai->ai_addrlen) < 0) {			/* Nope, try another */			close(s);			continue;		}				return s;	} 	rprintf(FERROR, RSYNC_NAME ": open inbound socket on port %d failed: "		"%s\n",		port, 		strerror(errno)); 	freeaddrinfo(all_ai);	return -1; }  /* * Determine if a file descriptor is in fact a socket */int is_a_socket(int fd){	int v;	socklen_t l;	l = sizeof(int);         /* Parameters to getsockopt, setsockopt etc are very         * unstandardized across platforms, so don't be surprised if         * there are compiler warnings on e.g. SCO OpenSwerver or AIX.         * It seems they all eventually get the right idea.         *         * Debian says: ``The fifth argument of getsockopt and         * setsockopt is in reality an int [*] (and this is what BSD         * 4.* and libc4 and libc5 have).  Some POSIX confusion         * resulted in the present socklen_t.  The draft standard has         * not been adopted yet, but glibc2 already follows it and         * also has socklen_t [*]. See also accept(2).''         *         * We now return to your regularly scheduled programming.  */	return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);}  void start_accept_loop(int port, int (*fn)(int )){	int s;	extern char *bind_address;	extern int default_af_hint; 	/* open an incoming socket */	s = open_socket_in(SOCK_STREAM, port, bind_address, default_af_hint);	if (s == -1)		exit_cleanup(RERR_SOCKETIO); 	/* ready to listen */	if (listen(s, 5) == -1) {		close(s);		exit_cleanup(RERR_SOCKETIO);	}  	/* now accept incoming connections - forking a new process	   for each incoming connection */	while (1) {		fd_set fds;		int fd;		struct sockaddr_storage addr;		socklen_t addrlen = sizeof addr; 		/* close log file before the potentially very long select so		   file can be trimmed by another process instead of growing		   forever */		log_close(); 		FD_ZERO(&fds);		FD_SET(s, &fds); 		if (select(s+1, &fds, NULL, NULL, NULL) != 1) {			continue;		} 		if(!FD_ISSET(s, &fds)) continue; 		fd = accept(s,(struct sockaddr *)&addr,&addrlen); 		if (fd == -1) continue; 		signal(SIGCHLD, SIG_IGN); 		/* we shouldn't have any children left hanging around		   but I have had reports that on Digital Unix zombies		   are produced, so this ensures that they are reaped */#ifdef WNOHANG                while (waitpid(-1, NULL, WNOHANG) > 0);#endif 		if (fork()==0) {			close(s);			/* open log file in child before possibly giving			   up privileges  */			log_open();			_exit(fn(fd));		} 		close(fd);	}}  enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON}; struct{  char *name;  int level;  int option;  int value;  int opttype;} socket_options[] = {  {"SO_KEEPALIVE",      SOL_SOCKET,    SO_KEEPALIVE,    0,                 OPT_BOOL},  {"SO_REUSEADDR",      SOL_SOCKET,    SO_REUSEADDR,    0,                 OPT_BOOL},  {"SO_BROADCAST",      SOL_SOCKET,    SO_BROADCAST,    0,                 OPT_BOOL},#ifdef TCP_NODELAY  {"TCP_NODELAY",       IPPROTO_TCP,   TCP_NODELAY,     0,                 OPT_BOOL},#endif#ifdef IPTOS_LOWDELAY  {"IPTOS_LOWDELAY",    IPPROTO_IP,    IP_TOS,          IPTOS_LOWDELAY,    OPT_ON},#endif#ifdef IPTOS_THROUGHPUT  {"IPTOS_THROUGHPUT",  IPPROTO_IP,    IP_TOS,          IPTOS_THROUGHPUT,  OPT_ON},#endif#ifdef SO_SNDBUF  {"SO_SNDBUF",         SOL_SOCKET,    SO_SNDBUF,       0,                 OPT_INT},#endif#ifdef SO_RCVBUF  {"SO_RCVBUF",         SOL_SOCKET,    SO_RCVBUF,       0,                 OPT_INT},#endif#ifdef SO_SNDLOWAT  {"SO_SNDLOWAT",       SOL_SOCKET,    SO_SNDLOWAT,     0,                 OPT_INT},#endif#ifdef SO_RCVLOWAT  {"SO_RCVLOWAT",       SOL_SOCKET,    SO_RCVLOWAT,     0,                 OPT_INT},#endif#ifdef SO_SNDTIMEO  {"SO_SNDTIMEO",       SOL_SOCKET,    SO_SNDTIMEO,     0,                 OPT_INT},#endif#ifdef SO_RCVTIMEO  {"SO_RCVTIMEO",       SOL_SOCKET,    SO_RCVTIMEO,     0,                 OPT_INT},#endif  {NULL,0,0,0,0}}; 	 /****************************************************************************set user socket options****************************************************************************/void set_socket_options(int fd, char *options){	char *tok;	if (!options || !*options) return; 	options = strdup(options);		if (!options) out_of_memory("set_socket_options"); 	for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) {		int ret=0,i;		int value = 1;		char *p;		int got_value = 0; 		if ((p = strchr(tok,'='))) {			*p = 0;			value = atoi(p+1);			got_value = 1;		}

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