json-rpc-test-server: try to fetch a name for us

AI_CANONNAME might not be the best thing but most of the code
will stay even if we go for a better method.

1 files changed, 29 insertions, 12 deletions

diff --git a/json-rpc-test-server.c b/json-rpc-test-server.c
index 99842f5..df4a1f3 100644
--- a/json-rpc-test-server.c
+++ b/json-rpc-test-server.c
@@ -2376,8 +2376,9 @@ static struct client_vtable client_fcgi_vtable =
 };
 
 static struct client *
-client_fcgi_create (EV_P_ int sock_fd)
+client_fcgi_create (EV_P_ const char *host, int sock_fd)
 {
+	(void) host;
 	struct client_fcgi *self = client_new (EV_A_ sizeof *self, sock_fd);
 	self->client.vtable = &client_fcgi_vtable;
 
@@ -2480,8 +2481,9 @@ static struct client_vtable client_scgi_vtable =
 };
 
 static struct client *
-client_scgi_create (EV_P_ int sock_fd)
+client_scgi_create (EV_P_ const char *host, int sock_fd)
 {
+	(void) host;
 	struct client_scgi *self = client_new (EV_A_ sizeof *self, sock_fd);
 	self->client.vtable = &client_scgi_vtable;
 
@@ -2576,8 +2578,9 @@ static struct client_vtable client_ws_vtable =
 };
 
 static struct client *
-client_ws_create (EV_P_ int sock_fd)
+client_ws_create (EV_P_ const char *host, int sock_fd)
 {
+	(void) host;
 	struct client_ws *self = client_new (EV_A_ sizeof *self, sock_fd);
 	self->client.vtable = &client_ws_vtable;
 
@@ -2754,13 +2757,15 @@ client_co_run (struct server_context *ctx)
 
 // --- Basic server stuff ------------------------------------------------------
 
-typedef struct client *(*client_create_fn) (EV_P_ int sock_fd);
+typedef struct client *
+	(*client_create_fn) (EV_P_ const char *host, int sock_fd);
 
 struct listener
 {
 	int fd;                             ///< Listening socket FD
 	ev_io watcher;                      ///< New connection available
 	client_create_fn create;            ///< Client constructor
+	char *host;                         ///< Hostname, IP or empty for any
 };
 
 static void
@@ -2775,6 +2780,8 @@ close_listeners (struct server_context *self)
 		ev_io_stop (EV_DEFAULT_ &listener->watcher);
 		xclose (listener->fd);
 		listener->fd = -1;
+
+		cstr_set (&listener->host, NULL);
 	}
 }
 
@@ -2824,7 +2831,7 @@ on_client_available (EV_P_ ev_io *watcher, int revents)
 	{
 		int sock_fd = accept (watcher->fd, NULL, NULL);
 		if (sock_fd != -1)
-			listener->create (EV_A_ sock_fd);
+			listener->create (EV_A_ listener->host, sock_fd);
 		else if (errno == EAGAIN)
 			return;
 		else if (errno != EINTR && errno != EMFILE
@@ -2854,7 +2861,8 @@ parse_config (struct server_context *ctx, struct error **e)
 }
 
 static int
-listener_bind (struct addrinfo *gai_iter)
+listener_bind (struct addrinfo *gai_iter,
+	char *host, size_t host_len, char *port, size_t port_len)
 {
 	int fd = socket (gai_iter->ai_family,
 		gai_iter->ai_socktype, gai_iter->ai_protocol);
@@ -2868,15 +2876,17 @@ listener_bind (struct addrinfo *gai_iter)
 	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
 		&yes, sizeof yes) != -1);
 
-	char host[NI_MAXHOST], port[NI_MAXSERV];
-	host[0] = port[0] = '\0';
+	*host = *port = 0;
 	int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
-		host, sizeof host, port, sizeof port,
-		NI_NUMERICHOST | NI_NUMERICSERV);
+		host, host_len, port, port_len, NI_NUMERICHOST | NI_NUMERICSERV);
 	if (err)
 		print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
 
+	// We're binding to a port but our caller prefers a hostname
 	char *address = format_host_port_pair (host, port);
+	if (gai_iter->ai_canonname)
+		snprintf (host, host_len, "%s", gai_iter->ai_canonname);
+
 	if (bind (fd, gai_iter->ai_addr, gai_iter->ai_addrlen))
 		print_error ("bind to %s failed: %s", address, strerror (errno));
 	else if (listen (fd, 16 /* arbitrary number */))
@@ -2909,9 +2919,11 @@ listener_add (struct server_context *ctx, const char *host, const char *port,
 	}
 
 	int fd;
+	char host_buf[NI_MAXHOST] = "", port_buf[NI_MAXSERV] = "";
 	for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next)
 	{
-		if ((fd = listener_bind (gai_iter)) == -1)
+		if ((fd = listener_bind (gai_iter,
+			host_buf, sizeof host_buf, port_buf, sizeof port_buf)) == -1)
 			continue;
 		set_blocking (fd, false);
 
@@ -2921,6 +2933,8 @@ listener_add (struct server_context *ctx, const char *host, const char *port,
 		listener->watcher.data = listener;
 		listener->create = create;
 		listener->fd = fd;
+		listener->host = xstrdup (host);
+		// The client will query the obtained socket for the port anyway
 		break;
 	}
 	freeaddrinfo (gai_result);
@@ -2938,7 +2952,7 @@ get_ports_from_config (struct server_context *ctx,
 static bool
 setup_listen_fds (struct server_context *ctx, struct error **e)
 {
-	static const struct addrinfo gai_hints =
+	static struct addrinfo gai_hints =
 	{
 		.ai_socktype = SOCK_STREAM,
 		.ai_flags = AI_PASSIVE,
@@ -2956,6 +2970,9 @@ setup_listen_fds (struct server_context *ctx, struct error **e)
 	size_t n_ports = ports_fcgi.len + ports_scgi.len + ports_ws.len;
 	ctx->listeners = xcalloc (n_ports, sizeof *ctx->listeners);
 
+	if (bind_host)
+		gai_hints.ai_flags |= AI_CANONNAME;
+
 	for (size_t i = 0; i < ports_fcgi.len; i++)
 		listener_add (ctx, bind_host, ports_fcgi.vector[i],
 			&gai_hints, client_fcgi_create);