Fix to correctly identify remote IP address and host name when using

[rsync/rsync.git] / clientname.c

diff --git a/clientname.c b/clientname.c
index 579089f..8d22fc8 100644 (file)
--- 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, (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, ss_len, name_buf, port_buf);
+               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,
@@ -226,12 +264,14 @@ 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;
@@ -241,7 +281,7 @@ int check_name(int fd,
        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",