X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/f75502950b37cf202332387df3af2dec27e65535..09021eabb53aec92237116d57d3e2b4246ef8f86:/clientname.c

diff --git a/clientname.c b/clientname.c
index f83eb8d3..8d22fc8b 100644
--- a/clientname.c
+++ b/clientname.c
@@ -43,6 +43,7 @@ char *client_addr(int fd)
 {
 	struct sockaddr_storage ss;
 	socklen_t length = sizeof ss;
+	char *ssh_client, *p;
 	static char addr_buf[100];
 	static int initialised;
 
@@ -50,11 +51,21 @@ char *client_addr(int fd)
 
 	initialised = 1;
 
-	client_sockaddr(fd, &ss, &length);
+	ssh_client = getenv("SSH_CLIENT");
+	if (ssh_client != NULL) {
+		strlcpy(addr_buf, ssh_client, sizeof(addr_buf));
+		/* truncate SSH_CLIENT to just IP address */
+		p = strchr(addr_buf, ' ');
+		if (p)
+			*p = '\0';
+		else
+			strlcpy(addr_buf, "0.0.0.0", sizeof("0.0.0.0"));
+	} else
+		client_sockaddr(fd, &ss, &length);
 
 	getnameinfo((struct sockaddr *)&ss, length,
-		    addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
-	
+		addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
+
 	return addr_buf;
 }
 
@@ -74,11 +85,12 @@ static int get_sockaddr_family(const struct sockaddr_storage *ss)
  * If anything goes wrong, including the name->addr->name check, then
  * we just use "UNKNOWN", so you can use that value in hosts allow
  * lines.
+ *
+ * After translation from sockaddr to name we do a forward lookup to
+ * make sure nobody is spoofing PTR records.
  **/
 char *client_name(int fd)
 {
-	struct sockaddr_storage ss;
-	socklen_t ss_len = sizeof ss;
 	static char name_buf[100];
 	static char port_buf[100];
 	static int initialised;
@@ -88,10 +100,34 @@ char *client_name(int fd)
 	strcpy(name_buf, default_name);
 	initialised = 1;
 
-	client_sockaddr(fd, &ss, &ss_len);
+	if (getenv("SSH_CLIENT") != NULL) {
+		/* Look up name of IP address given in $SSH_CLIENT */
+#ifdef INET6
+		int af = AF_INET6;
+		struct sockaddr_in6 sin;
+#else
+		int af = AF_INET;
+		struct sockaddr_in sin;
+#endif
+		socklen_t sin_len = sizeof sin;
+
+		memset(&sin, 0, sin_len);
+		sin.sin_family = af;
+		inet_pton(af, client_addr(fd), &sin.sin_addr.s_addr);
 
-	if (!lookup_name(fd, &ss, ss_len, name_buf, sizeof name_buf, port_buf, sizeof port_buf))
-		check_name(fd, &ss, ss_len, name_buf, port_buf);
+		if (!lookup_name(fd, (struct sockaddr_storage *)&sin, sin_len, 
+				name_buf, sizeof name_buf, port_buf, sizeof port_buf))
+			check_name(fd, (struct sockaddr_storage *)&sin, name_buf);
+	} else {
+		struct sockaddr_storage ss;
+		socklen_t ss_len = sizeof ss;
+
+		client_sockaddr(fd, &ss, &ss_len);
+
+		if (!lookup_name(fd, &ss, ss_len, name_buf, sizeof name_buf, 
+				port_buf, sizeof port_buf))
+			check_name(fd, &ss, name_buf);
+	}
 
 	return name_buf;
 }
@@ -149,6 +185,8 @@ void client_sockaddr(int fd,
 
 /**
  * Look up a name from @p ss into @p name_buf.
+ *
+ * @param fd file descriptor for client socket.
  **/
 int lookup_name(int fd, const struct sockaddr_storage *ss,
 		socklen_t ss_len,
@@ -185,7 +223,6 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
 {
 	int ss_family = get_sockaddr_family(ss);
 	const char fn[] = "compare_addrinfo_sockaddr";
-	size_t valid_len;
 		      
 	if (ai->ai_family != ss_family) {
 		rprintf(FERROR,
@@ -194,21 +231,31 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
 		return 1;
 	}
 
-	switch (ss_family) {
-	case AF_INET:
-		valid_len = sizeof (struct sockaddr_in);
-		break;
+	/* The comparison method depends on the particular AF. */
+	if (ss_family == AF_INET) {
+		const struct sockaddr_in *sin1, *sin2;
+
+		sin1 = (const struct sockaddr_in *) ss;
+		sin2 = (const struct sockaddr_in *) ai->ai_addr;
+		
+		return memcmp(&sin1->sin_addr, &sin2->sin_addr,
+			      sizeof sin1->sin_addr);
+	}
 #ifdef INET6
-	case AF_INET6:
-		valid_len = sizeof (struct sockaddr_in6);
-		break;
-#endif
-	default:
-		/* Don't know what to do! */
+	else if (ss_family == AF_INET6) {
+		const struct sockaddr_in6 *sin1, *sin2;
+
+		sin1 = (const struct sockaddr_in6 *) ss;
+		sin2 = (const struct sockaddr_in6 *) ai->ai_addr;
+		
+		return memcmp(&sin1->sin6_addr, &sin2->sin6_addr,
+			      sizeof sin1->sin6_addr);
+	}
+#endif /* INET6 */
+	else {
+		/* don't know */
 		return 1;
 	}
-
-	return memcmp(ss, ai->ai_addr, valid_len);
 }
 
 
@@ -217,22 +264,24 @@ int compare_addrinfo_sockaddr(const struct addrinfo *ai,
  * @p ss -- otherwise we may be being spoofed.  If we suspect we are,
  * then we don't abort the connection but just emit a warning, and
  * change @p name_buf to be "UNKNOWN".
+ *
+ * We don't do anything with the service when checking the name,
+ * because it doesn't seem that it could be spoofed in any way, and
+ * getaddrinfo on random service names seems to cause problems on AIX.
  **/
 int check_name(int fd,
 	       const struct sockaddr_storage *ss,
-	       socklen_t ss_len,
-	       char *name_buf,
-	       const char *port_buf)
+	       char *name_buf)
 {
 	struct addrinfo hints, *res, *res0;
 	int error;
 	int ss_family = get_sockaddr_family(ss);
 
 	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = PF_UNSPEC;
-	hints.ai_flags = ss_family;
+	hints.ai_family = ss_family;
+	hints.ai_flags = AI_CANONNAME;
 	hints.ai_socktype = SOCK_STREAM;
-	error = getaddrinfo(name_buf, port_buf, &hints, &res0);
+	error = getaddrinfo(name_buf, NULL, &hints, &res0);
 	if (error) {
 		rprintf(FERROR,
 			RSYNC_NAME ": forward name lookup for %s failed: %s\n",