X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/ff8b29b8c62f377ede40fbf0cbbaa428bd8df60a..27d3cdbc943a57d64f4f2a35a4f1e1b15d9ca41f:/socket.c

diff --git a/socket.c b/socket.c
index 5ee31f6d..15d991b4 100644
--- a/socket.c
+++ b/socket.c
@@ -54,6 +54,8 @@ int open_socket_out(char *host, int port)
 		return -1;
 	}
 
+	set_nonblocking(res);
+
 	return res;
 }
 
@@ -81,7 +83,7 @@ static int open_socket_in(int type, int port)
 		return -1;
 	}
   
-	bzero((char *)&sock,sizeof(sock));
+	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;
@@ -110,9 +112,9 @@ 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);
+	int v,l;
+	l = sizeof(int);
+	return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
 }
 
 
@@ -120,17 +122,15 @@ void start_accept_loop(int port, int (*fn)(int ))
 {
 	int s;
 
-	signal(SIGCLD, SIG_IGN);
-
 	/* open an incoming socket */
 	s = open_socket_in(SOCK_STREAM, port);
 	if (s == -1)
-		exit(1);
+		exit_cleanup(1);
 
 	/* ready to listen */
 	if (listen(s, 5) == -1) {
 		close(s);
-		exit(1);
+		exit_cleanup(1);
 	}
 
 
@@ -155,9 +155,20 @@ void start_accept_loop(int port, int (*fn)(int ))
 
 		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
+		waitpid(-1, NULL, WNOHANG);
+#endif
+
 		if (fork()==0) {
 			close(s);
 
+			set_nonblocking(fd);
+
 			_exit(fn(fd));
 		}
 
@@ -216,6 +227,8 @@ 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");
@@ -272,27 +285,30 @@ become a daemon, discarding the controlling terminal
 ****************************************************************************/
 void become_daemon(void)
 {
-	if (fork())
+	int i;
+
+	if (fork()) {
 		_exit(0);
+	}
 
 	/* detach from the terminal */
 #ifdef HAVE_SETSID
 	setsid();
 #else
 #ifdef TIOCNOTTY
-	{
-		int i = open("/dev/tty", O_RDWR);
-		if (i >= 0) 
-			{
-				ioctl(i, (int) TIOCNOTTY, (char *)0);      
-				close(i);
-			}
+	i = open("/dev/tty", O_RDWR);
+	if (i >= 0) {
+		ioctl(i, (int) TIOCNOTTY, (char *)0);      
+		close(i);
 	}
 #endif /* TIOCNOTTY */
 #endif
-	close(0);
-	close(1);
-	close(2);
+	/* 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);
+	}
 }
 
 /*******************************************************************
@@ -304,13 +320,17 @@ char *client_addr(int fd)
 	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(1);
+		exit_cleanup(1);
 	}
-
+	
 	strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)-1);
-
 	return addr_buf;
 }
 
@@ -325,11 +345,18 @@ char *client_name(int fd)
 	int     length = sizeof(sa);
 	static char name_buf[100];
 	struct hostent *hp;
+	char **p;
+	char *def = "UNKNOWN";
+	static int initialised;
 
-	strcpy(name_buf,"UNKNOWN");
+	if (initialised) return name_buf;
+
+	initialised = 1;
+
+	strcpy(name_buf,def);
 
 	if (getpeername(fd, &sa, &length)) {
-		exit(1);
+		exit_cleanup(1);
 	}
 
 	/* Look up the remote host name. */
@@ -339,5 +366,23 @@ char *client_name(int fd)
 		strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf) - 1);
 	}
 
+
+	/* 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;
 }