X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/654175798bdbdd6403e10c8fa74e8586b3612ea1..b964901f7d01ad04717535ce3d328200d616be32:/socket.c

diff --git a/socket.c b/socket.c
index 6fd4e365..5e037605 100644
--- a/socket.c
+++ b/socket.c
@@ -1,5 +1,7 @@
-/* 
-   Copyright (C) Andrew Tridgell 1998
+/* -*- c-file-style: "linux" -*-
+   
+   Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
+   Copyright (C) 2001 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
@@ -23,74 +25,196 @@
 
 #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)) != 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;
+}
+
+
+
 /* open a socket to a tcp remote host with the specified port 
-   based on code from Warren */
-int open_socket_out(char *host, int port)
+   based on code from Warren
+   proxy support by Stephen Rothwell */
+static 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: should be HOST:PORT\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(host);
+	hp = gethostbyname(h);
 	if (!hp) {
-		rprintf(FERROR,"unknown host: %s\n", host);
+		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(port);
+	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, RSYNC_NAME ": failed to connect to host %s: %s\n",
+			 h, strerror(errno));
 		close(res);
-		rprintf(FERROR,"failed to connect to %s - %s\n", host, strerror(errno));
 		return -1;
 	}
 
-	set_nonblocking(res);
+	if (proxied && establish_proxy_connection(res, host, port) != 0) {
+		close(res);
+		return -1;
+	}
 
 	return res;
 }
 
 
+/**
+ * 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.
+ **/
+int open_socket_out_wrapped (char *host,
+			     int port,
+			     struct in_addr *address)
+{
+	char *prog;
+
+	if ((prog = getenv ("RSYNC_CONNECT_PROG")) != NULL) 
+		return sock_exec (prog);
+	else 
+		return open_socket_out (host, port, address);
+}
+
+
+
 /****************************************************************************
 open a socket of the specified type, port and address for incoming data
 ****************************************************************************/
-static int open_socket_in(int type, int port)
+static int open_socket_in(int type, int port, struct in_addr *address)
 {
-	struct hostent *hp;
 	struct sockaddr_in sock;
-	char host_name[200];
 	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;
-	sock.sin_addr.s_addr = INADDR_ANY;
-	res = socket(hp->h_addrtype, type, 0);
+	sock.sin_family = AF_INET;
+	if (address) {
+		sock.sin_addr = *address;
+	} else {
+		sock.sin_addr.s_addr = INADDR_ANY;
+	}
+	res = socket(AF_INET, type, 0);
 	if (res == -1) { 
-		rprintf(FERROR,"socket failed\n"); 
+		rprintf(FERROR, RSYNC_NAME ": socket failed: %s\n",
+			strerror(errno)); 
 		return -1; 
 	}
 
@@ -98,7 +222,12 @@ static int open_socket_in(int type, int port)
 
 	/* 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);
+		rprintf(FERROR,"bind failed on port %d: %s\n", port,
+			strerror(errno));
+		if (errno == EACCES && port < 1024) {
+			rprintf(FERROR, "Note: you must be root to bind "
+				"to low-numbered ports");
+		}
 		close(res); 
 		return -1;
 	}
@@ -107,13 +236,28 @@ static int open_socket_in(int type, int port)
 }
 
 
-/****************************************************************************
-determine if a file descriptor is in fact a socket
-****************************************************************************/
+/*
+ * Determine if a file descriptor is in fact a socket
+ */
 int is_a_socket(int fd)
 {
-	int v,l;
+	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);
 }
 
@@ -121,9 +265,10 @@ int is_a_socket(int fd)
 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);
+	s = open_socket_in(SOCK_STREAM, port, &socket_address);
 	if (s == -1)
 		exit_cleanup(RERR_SOCKETIO);
 
@@ -140,7 +285,12 @@ void start_accept_loop(int port, int (*fn)(int ))
 		fd_set fds;
 		int fd;
 		struct sockaddr addr;
-		int in_addrlen = sizeof(addr);
+		socklen_t in_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);
@@ -151,7 +301,8 @@ void start_accept_loop(int port, int (*fn)(int ))
 
 		if(!FD_ISSET(s, &fds)) continue;
 
-		fd = accept(s,&addr,&in_addrlen);
+                /* See note above prototypes. */
+		fd = accept(s,&addr, &in_addrlen);
 
 		if (fd == -1) continue;
 
@@ -161,13 +312,15 @@ void start_accept_loop(int port, int (*fn)(int ))
 		   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);
+                while (waitpid(-1, NULL, WNOHANG) > 0);
 #endif
 
 		if (fork()==0) {
 			close(s);
 
-			set_nonblocking(fd);
+			/* open log file in child before possibly giving
+			   up privileges  */
+			log_open();
 
 			_exit(fn(fd));
 		}
@@ -274,7 +427,8 @@ void set_socket_options(int fd, char *options)
 		}
 		
 		if (ret != 0)
-			rprintf(FERROR,"Failed to set socket option %s\n",tok);
+			rprintf(FERROR, "failed to set socket option %s: %s\n", tok,
+				strerror(errno));
 	}
 
 	free(options);
@@ -318,7 +472,7 @@ char *client_addr(int fd)
 {
 	struct sockaddr sa;
 	struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
-	int     length = sizeof(sa);
+	socklen_t length = sizeof(sa);
 	static char addr_buf[100];
 	static int initialised;
 
@@ -330,7 +484,7 @@ char *client_addr(int fd)
 		exit_cleanup(RERR_SOCKETIO);
 	}
 	
-	strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)-1);
+	strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf));
 	return addr_buf;
 }
 
@@ -342,7 +496,7 @@ char *client_name(int fd)
 {
 	struct sockaddr sa;
 	struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa);
-	int     length = sizeof(sa);
+	socklen_t length = sizeof(sa);
 	static char name_buf[100];
 	struct hostent *hp;
 	char **p;
@@ -363,15 +517,16 @@ char *client_name(int fd)
 	if ((hp = gethostbyaddr((char *) &sockin->sin_addr,
 				sizeof(sockin->sin_addr),
 				AF_INET))) {
-		strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf) - 1);
+		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");
+		strcpy (name_buf,def);
+		rprintf (FERROR, "reverse name lookup for \"%s\" failed\n",
+			name_buf);
 	} else {
 		for (p=hp->h_addr_list;*p;p++) {
 			if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) {
@@ -386,3 +541,167 @@ char *client_name(int fd)
 
 	return name_buf;
 }
+
+/**
+   Convert a string to an IP address. The string can be a name or
+   dotted decimal number.
+
+   Returns a pointer to a static in_addr struct -- if you call this
+   more than once then you should copy it.
+*/
+struct in_addr *ip_address(const char *str)
+{
+	static struct in_addr ret;
+	struct hostent *hp;
+
+	if (!str) {
+		rprintf (FERROR, "ip_address received NULL name\n");
+		return NULL;
+	}
+
+	/* try as an IP address */
+	if (inet_aton(str, &ret) != 0) {
+		return &ret;
+	}
+
+	/* otherwise assume it's a network name of some sort and use 
+	   gethostbyname */
+	if ((hp = gethostbyname (str)) == 0) {
+		rprintf(FERROR, "gethostbyname failed for \"%s\": unknown host?\n",str);
+		return NULL;
+	}
+
+	if (hp->h_addr == NULL) {
+		rprintf(FERROR, "gethostbyname: host address is invalid for host \"%s\"\n",str);
+		return NULL;
+	}
+
+	if (hp->h_length > sizeof ret) {
+		rprintf(FERROR, "gethostbyname: host address for \"%s\" is too large\n",
+			str);
+		return NULL;
+	}
+
+	if (hp->h_addrtype != AF_INET) {
+		rprintf (FERROR, "gethostname: host address for \"%s\" is not IPv4\n",
+			 str);
+		return NULL;
+	}
+
+	/* This is kind of difficult.  The only field in ret is
+	   s_addr, which is the IP address as a 32-bit int.  On
+	   UNICOS, s_addr is in fact a *bitfield* for reasons best
+	   know to Cray.  This means we can't memcpy in to it.  On the
+	   other hand, h_addr is a char*, so we can't just assign.
+
+	   Since there's meant to be only one field inside the in_addr
+	   structure we will try just copying over the top and see how
+	   that goes. */
+	memcpy (&ret, hp->h_addr, hp->h_length);
+
+	return &ret;
+}
+
+
+
+/*******************************************************************
+this is like socketpair but uses tcp. It is used by the Samba
+regression test code
+The function guarantees that nobody else can attach to the socket,
+or if they do that this function fails and the socket gets closed
+returns 0 on success, -1 on failure
+the resulting file descriptors are symmetrical
+ ******************************************************************/
+static int socketpair_tcp(int fd[2])
+{
+	int listener;
+	struct sockaddr_in sock;
+	struct sockaddr_in sock2;
+	socklen_t socklen = sizeof(sock);
+	int connect_done = 0;
+	
+	fd[0] = fd[1] = listener = -1;
+
+	memset(&sock, 0, sizeof(sock));
+	
+	if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+        memset(&sock2, 0, sizeof(sock2));
+#ifdef HAVE_SOCK_SIN_LEN
+        sock2.sin_len = sizeof(sock2);
+#endif
+        sock2.sin_family = PF_INET;
+
+        bind(listener, (struct sockaddr *)&sock2, sizeof(sock2));
+
+	if (listen(listener, 1) != 0) goto failed;
+
+	if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
+
+	if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+	set_nonblocking(fd[1]);
+
+	sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) == -1) {
+		if (errno != EINPROGRESS) goto failed;
+	} else {
+		connect_done = 1;
+	}
+
+	if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
+
+	close(listener);
+	if (connect_done == 0) {
+		if (connect(fd[1],(struct sockaddr *)&sock,sizeof(sock)) != 0
+		    && errno != EISCONN) goto failed;
+	}
+
+	set_blocking (fd[1]);
+
+	/* all OK! */
+	return 0;
+
+ failed:
+	if (fd[0] != -1) close(fd[0]);
+	if (fd[1] != -1) close(fd[1]);
+	if (listener != -1) close(listener);
+	return -1;
+}
+
+
+/*******************************************************************
+run a program on a local tcp socket, this is used to launch smbd
+when regression testing
+the return value is a socket which is attached to a subprocess
+running "prog". stdin and stdout are attached. stderr is left
+attached to the original stderr
+ ******************************************************************/
+int sock_exec(const char *prog)
+{
+	int fd[2];
+	if (socketpair_tcp(fd) != 0) {
+		rprintf (FERROR, RSYNC_NAME
+			 ": socketpair_tcp failed (%s)\n",
+			 strerror(errno));
+		return -1;
+	}
+	if (fork() == 0) {
+		close(fd[0]);
+		close(0);
+		close(1);
+		dup(fd[1]);
+		dup(fd[1]);
+		if (verbose > 3)
+			fprintf (stderr,
+				 RSYNC_NAME ": execute socket program \"%s\"\n",
+				 prog);
+		exit (system (prog));
+	}
+	close (fd[1]);
+	return fd[0];
+}
+
+
+