addrinfo: Set numeric conversions if appropriate

If the passed in address or port is numeric, set the proper flags for numeric conversions so the nameserver won't be used for the conversions. Signed-off-by: Corey Minyard <[email protected]>
cminyard · Jul 4, 2024 · b17edd4 · b17edd4
1 parent 9a32698
commit b17edd4
Showing 1 changed file with 28 additions and 0 deletions.
diff --git a/lib/gensio_addrinfo.c b/lib/gensio_addrinfo.c
@@ -727,6 +727,8 @@ gensio_addr_addrinfo_scan_ips(struct gensio_os_funcs *o, const char *str,
     bool first = true, portset = false;
     int rv = 0, socktype, protocol;
     int bflags = AI_ADDRCONFIG;
+    struct sockaddr_storage iaddr;
+    char *end;
 
     switch (gprotocol) {
     case GENSIO_NET_PROTOCOL_UNSPEC:
@@ -869,7 +871,33 @@ gensio_addr_addrinfo_scan_ips(struct gensio_os_funcs *o, const char *str,
 	 */
 	if (!ip && notype)
 	    rflags |= AI_V4MAPPED;
+#endif
 
+	/*
+	 * If the host address is a valid IP address, skip the
+	 * nameserver lookup and just tell getaddrinfo to convert the
+	 * numeric value.
+	 */
+	if (ip) {
+	    if (family == AF_INET && inet_pton(AF_INET, ip, &iaddr) == 1)
+		rflags |= AI_NUMERICHOST;
+#ifdef AF_INET6
+	    else if (family == AF_INET6) {
+		if (inet_pton(AF_INET6, ip, &iaddr) == 1)
+		    rflags |= AI_NUMERICHOST;
+		else if (rflags & AI_V4MAPPED &&
+			inet_pton(AF_INET, ip, &iaddr) == 1)
+		    rflags |= AI_NUMERICHOST;
+	    }
+#endif
+	}
+	/*
+	 * If the port string is a number, just use the number and don't
+	 * do the nameserver lookup for the service.
+	 */
+	if (port && strtoul(port, &end, 10) < 65536 && *end == '\0')
+	    rflags |= AI_NUMERICSERV;
+#ifdef AF_INET6
     redo_getaddrinfo:
 #endif
 	memset(&hints, 0, sizeof(hints));