X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/13e29995f5f08300ea946374079dff50f8cb6bd7..362099a51230fd80c6d54ef6f0e72927529c8dfb:/socket.c

diff --git a/socket.c b/socket.c
index 850cb144..520c3d5c 100644
--- a/socket.c
+++ b/socket.c
@@ -1,7 +1,7 @@
 /* -*- c-file-style: "linux" -*-
    
    Copyright (C) 1992-2001 by Andrew Tridgell <tridge@samba.org>
-   Copyright (C) 2001 by Martin Pool <mbp@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
@@ -22,6 +22,11 @@
  * @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"
@@ -90,6 +95,39 @@ static int establish_proxy_connection(int fd, char *host, int port)
 }
 
 
+/**
+ * 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 (getaddrinfo(bind_address, NULL, &bhints, &bres_all) == -1) {
+		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 .
@@ -167,31 +205,13 @@ int open_socket_out(char *host, int port, const char *bind_address,
 		if (s < 0)
 			continue;
 
-		if (bind_address) {
-			struct addrinfo bhints, *bres;
-
-			memset(&bhints, 0, sizeof(bhints));
-			bhints.ai_family = res->ai_family;
-			bhints.ai_socktype = type;
-			bhints.ai_flags = AI_PASSIVE;
-			error = getaddrinfo(bind_address, NULL, &bhints, &bres);
-			if (error) {
-				rprintf(FERROR, RSYNC_NAME ": getaddrinfo: "
-					"bind address %s <noport>: %s\n",
-					bind_address, gai_strerror(error));
-				continue;
-			}
-			if (bres->ai_next) {
-				/* I'm not at all sure that this is the right
-				 * response here... -- mbp */
-				rprintf(FERROR, RSYNC_NAME ": getaddrinfo: "
-					"bind address %s resolved to multiple hosts\n",
-					bind_address);
-				freeaddrinfo(bres);
+		if (bind_address)
+			if (try_bind_local(s, res->ai_family, type,
+					   bind_address) == -1) {
+				close(s);
+				s = -1;
 				continue;
 			}
-			bind(s, bres->ai_addr, bres->ai_addrlen);
-		}
 
 		if (connect(s, res->ai_addr, res->ai_addrlen) < 0) {
 			close(s);
@@ -604,6 +624,12 @@ char *client_name(int fd)
 #ifdef INET6
         if (get_sockaddr_family(&ss) == AF_INET6 && 
 	    IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
+		/* OK, so ss is in the IPv6 family, but it is really
+		 * an IPv4 address: something like
+		 * "::ffff:10.130.1.2".  If we use it as-is, then the
+		 * reverse lookup might fail or perhaps something else
+		 * bad might happen.  So instead we convert it to an
+		 * equivalent address in the IPv4 address family.  */
 		struct sockaddr_in6 sin6;
 		struct sockaddr_in *sin;
 
@@ -616,6 +642,9 @@ char *client_name(int fd)
 		sin->sin_len = length;
 #endif
 		sin->sin_port = sin6.sin6_port;
+		/* FIXME: Isn't there a macro we can use here rather
+		 * than grovelling through the struct?  It might be
+		 * wrong on some systems. */
 		memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12],
 			sizeof(sin->sin_addr));
         }
@@ -654,13 +683,11 @@ char *client_name(int fd)
 			break;
 	}
 
-	/* TODO: Do a  forward lookup as well to prevent spoofing */
-
 	if (res == NULL) {
 		strcpy(name_buf, def);
 		rprintf(FERROR, RSYNC_NAME ": "
-			"reverse name lookup mismatch on fd%d - spoofed address?\n",
-			fd);
+			"reverse name lookup for \"%s\" failed on fd%d - spoofed address? \n",
+			name_buf, fd);
 	}
 
 	freeaddrinfo(res0);