+ /* 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);
+ }
+}
+
+/**
+ * Return the IP addr of the client as a string
+ **/
+char *client_addr(int fd)
+{
+ struct sockaddr_storage ss;
+ socklen_t length = sizeof ss;
+ static char addr_buf[100];
+ static int initialised;
+
+ if (initialised) return addr_buf;
+
+ initialised = 1;
+
+ if (getpeername(fd, (struct sockaddr *)&ss, &length)) {
+ exit_cleanup(RERR_SOCKETIO);
+ }
+
+ getnameinfo((struct sockaddr *)&ss, length,
+ addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
+ return addr_buf;
+}
+
+
+static int get_sockaddr_family(const struct sockaddr_storage *ss)
+{
+ return ((struct sockaddr *) ss)->sa_family;
+}
+
+
+/**
+ * Return the DNS name of the client.
+ *
+ * The name is statically cached so that repeated lookups are quick,
+ * so there is a limit of one lookup per customer.
+ *
+ * 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.
+ **/
+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;
+
+ if (initialised) return name_buf;
+
+ strcpy(name_buf, default_name);
+ initialised = 1;
+
+ if (getpeername(fd, (struct sockaddr *)&ss, &ss_len)) {
+ /* FIXME: Can we really not continue? */
+ rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n",
+ fd, strerror(errno));
+ exit_cleanup(RERR_SOCKETIO);
+ }
+
+ if (!lookup_name(&ss, ss_len, name_buf, sizeof name_buf, port_buf, sizeof port_buf))
+ check_name(&ss, ss_len, name_buf, port_buf);
+
+ return name_buf;
+}
+
+
+/**
+ * Look up a name from @p ss into @p name_buf.
+ **/
+static int lookup_name(const struct sockaddr_storage *ss,
+ socklen_t ss_len,
+ char *name_buf, size_t name_buf_len,
+ char *port_buf, size_t port_buf_len)
+{
+ int name_err;
+
+#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;
+
+ memcpy(&sin6, ss, sizeof(sin6));
+ sin = (struct sockaddr_in *)ss;
+ memset(sin, 0, sizeof(*sin));
+ sin->sin_family = AF_INET;
+ ss_len = sizeof(struct sockaddr_in);
+#ifdef HAVE_SOCKADDR_LEN
+ sin->sin_len = ss_len;
+#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));
+ }
+#endif
+
+ /* reverse lookup */
+ name_err = getnameinfo((struct sockaddr *) ss, ss_len,
+ name_buf, name_buf_len,
+ port_buf, port_buf_len,
+ NI_NAMEREQD | NI_NUMERICSERV);
+ if (name_err != 0) {
+ strcpy(name_buf, default_name);
+ rprintf(FERROR, RSYNC_NAME ": name lookup failed: %s\n",
+ gai_strerror(name_err));
+ return name_err;
+ }
+
+ return 0;