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/*    Copyright (C) Andrew Tridgell 1998      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.*/ /*  socket functions used in rsync    */ #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; 	slprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port);	if (write(fd, buffer, strlen(buffer)) != 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\n");			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\n");				return -1;			}			if (*cp == '\n')				break;		}		if ((cp > buffer) && (*cp == '\n'))			cp--;		if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r')))			break;	}	return 0;}  /* open a socket to a tcp remote host with the specified port    based on code from Warren   proxy support by Stephen Rothwell */int open_socket_out(char *host, int port, struct in_addr *address){	int type = SOCK_STREAM;	struct sockaddr_in sock_out;	struct sockaddr_in sock;	int res;	struct hostent *hp;	char *h;	unsigned p;	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\n");			return -1;		}		*cp++ = '\0';		p = atoi(cp);		h = buffer;	} else {		h = host;		p = port;	} 	res = socket(PF_INET, type, 0);	if (res == -1) {		return -1;	} 	hp = gethostbyname(h);	if (!hp) {		rprintf(FERROR,"unknown host: %s\n", h);		close(res);		return -1;	} 	memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length);	sock_out.sin_port = htons(p);	sock_out.sin_family = PF_INET; 	if (address) {		sock.sin_addr = *address;		sock.sin_port = 0;		sock.sin_family = hp->h_addrtype;		bind(res, (struct sockaddr * ) &sock,sizeof(sock));	} 	if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) {		rprintf(FERROR,"failed to connect to %s - %s\n", h, strerror(errno));		close(res);		return -1;	} 	if (proxied && establish_proxy_connection(res, host, port) != 0) {		close(res);		return -1;	} 	return res;}  /****************************************************************************open a socket of the specified type, port and address for incoming data****************************************************************************/static int open_socket_in(int type, int port, struct in_addr *address){	struct hostent *hp;	struct sockaddr_in sock;	char host_name[MAXHOSTNAMELEN];	int res;	int one=1; 	/* get my host name */	if (gethostname(host_name, sizeof(host_name)) == -1) { 		rprintf(FERROR,"gethostname failed\n"); 		return -1; 	}  	/* get host info */	if ((hp = gethostbyname(host_name)) == 0) {		rprintf(FERROR,"gethostbyname: Unknown host %s\n",host_name);		return -1;	}  	memset((char *)&sock,0,sizeof(sock));	memcpy((char *)&sock.sin_addr,(char *)hp->h_addr, hp->h_length);	sock.sin_port = htons(port);	sock.sin_family = hp->h_addrtype;	if (address) {		sock.sin_addr = *address;	} else {		sock.sin_addr.s_addr = INADDR_ANY;	}	res = socket(hp->h_addrtype, type, 0);	if (res == -1) { 		rprintf(FERROR,"socket failed\n"); 		return -1; 	} 	setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); 	/* now we've got a socket - we need to bind it */	if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) { 		rprintf(FERROR,"bind failed on port %d\n", port);		close(res); 		return -1;	} 	return res;}  /****************************************************************************determine if a file descriptor is in fact a socket****************************************************************************/int is_a_socket(int fd){	int v,l;	l = sizeof(int);	return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);}  void start_accept_loop(int port, int (*fn)(int )){	int s;	extern struct in_addr socket_address; 	/* open an incoming socket */	s = open_socket_in(SOCK_STREAM, port, &socket_address);	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 addr;		int in_addrlen = sizeof(addr); 		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,&addr,&in_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); 			_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;		} 		for (i=0;socket_options[i].name;i++)			if (strcmp(socket_options[i].name,tok)==0)				break; 		if (!socket_options[i].name) {			rprintf(FERROR,"Unknown socket option %s\n",tok);			continue;		} 		switch (socket_options[i].opttype) {		case OPT_BOOL:		case OPT_INT:			ret = setsockopt(fd,socket_options[i].level,					 socket_options[i].option,(char *)&value,sizeof(int));			break;					case OPT_ON:			if (got_value)				rprintf(FERROR,"syntax error - %s does not take a value\n",tok); 			{				int on = socket_options[i].value;				ret = setsockopt(fd,socket_options[i].level,						 socket_options[i].option,(char *)&on,sizeof(int));			}			break;	  		}				if (ret != 0)			rprintf(FERROR,"Failed to set socket option %s\n",tok);	} 	free(options);} /****************************************************************************become a daemon, discarding the controlling terminal****************************************************************************/void become_daemon(void){	int i; 	if (fork()) {		_exit(0);	} 	/* detach from the terminal */#ifdef HAVE_SETSID	setsid();#else#ifdef TIOCNOTTY	i = open("/dev/tty", O_RDWR);	if (i >= 0) {		ioctl(i, (int) TIOCNOTTY, (char *)0);      		close(i);	}#endif /* TIOCNOTTY */#endif	/* make sure that stdin, stdout an stderr don't stuff things           up (library functions, for example) */	for (i=0;i<3;i++) {		close(i); 		open("/dev/null", O_RDWR);	}} /******************************************************************* return the IP addr of the client as a string  ******************************************************************/char *client_addr(int fd){	struct sockaddr sa;	struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);	int     length = sizeof(sa);	static char addr_buf[100];	static int initialised; 	if (initialised) return addr_buf; 	initialised = 1; 	if (getpeername(fd, &sa, &length)) {		exit_cleanup(RERR_SOCKETIO);	}		strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf));	return addr_buf;}  /******************************************************************* return the DNS name of the client  ******************************************************************/char *client_name(int fd){	struct sockaddr sa;	struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);	int     length = sizeof(sa);	static char name_buf[100];	struct hostent *hp;	char **p;	char *def = "UNKNOWN";	static int initialised; 	if (initialised) return name_buf; 	initialised = 1; 	strcpy(name_buf,def); 	if (getpeername(fd, &sa, &length)) {		exit_cleanup(RERR_SOCKETIO);	} 	/* Look up the remote host name. */	if ((hp = gethostbyaddr((char *) &sockin->sin_addr,				sizeof(sockin->sin_addr),				AF_INET))) {		strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf));	}  	/* do a forward lookup as well to prevent spoofing */	hp = gethostbyname(name_buf);	if (!hp) {		strcpy(name_buf,def);		rprintf(FERROR,"reverse name lookup failed\n");	} else {		for (p=hp->h_addr_list;*p;p++) {			if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) {				break;			}		}		if (!*p) {			strcpy(name_buf,def);			rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n");		} 	} 	return name_buf;} /*******************************************************************convert a string to an IP address. The string can be a name ordotted decimal number  ******************************************************************/struct in_addr *ip_address(const char *str){	static struct in_addr ret;	struct hostent *hp;

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