Initial support for inetd/on-demand services \o/

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

inetd.c

@@ -0,0 +1,137 @@
+/* Classic inetd services launcher for Finit
+ *
+ * Copyright (c) 2015  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+//#include <unistd.h>
+//#include <sys/types.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "finit.h"
+#include "svc.h"
+#include "helpers.h"
+#include "libuev/uev.h"
+
+/* Socket callback, looks up correct svc and starts it as an inetd service */
+static void socket_cb(uev_ctx_t *UNUSED(ctx), uev_t *w, void *arg, int UNUSED(events))
+{
+	svc_t *svc = (svc_t *)arg;
+
+	if (SVC_START != svc_enabled(svc, 1, NULL))
+		return;
+
+	if (!svc->forking)
+		uev_io_stop(w);
+
+	svc_start(svc);
+}
+
+/* Launch Inet socket for service.
+ * TODO: Add filtering ALLOW/DENY per interface.
+ */
+static void spawn_socket(uev_ctx_t *ctx, svc_t *svc)
+{
+	int sd;
+	socklen_t len = sizeof(struct sockaddr);
+	struct sockaddr_in s;
+
+	if (!svc->sock_type) {
+		FLOG_ERROR("Skipping invalid inetd service %s", svc->cmd);
+		return;
+	}
+
+	sd = socket(AF_INET, svc->sock_type | SOCK_NONBLOCK, svc->proto);
+	if (-1 == sd) {
+		FLOG_PERROR("Failed opening inetd socket type %d proto %d", svc->sock_type, svc->proto);
+		return;
+	}
+
+	memset(&s, 0, sizeof(s));
+	s.sin_family      = AF_INET;
+	s.sin_addr.s_addr = INADDR_ANY;
+	s.sin_port        = htons(svc->port);
+	if (bind(sd, (struct sockaddr *)&s, len) < 0) {
+		FLOG_PERROR("Failed binding to port %d, maybe another %s server is already running",
+			    svc->port, svc->service);
+		close(sd);
+		return;
+	}
+
+	if (svc->port && svc->sock_type != SOCK_DGRAM) {
+		if (-1 == listen(sd, 20)) {
+			FLOG_PERROR("Failed listening to inetd service %s", svc->service);
+			close(sd);
+			return;
+		}
+	}
+
+	_d("Initializing inetd %s service %s type %d proto %d on socket %d ...",
+	   svc->service, basename(svc->cmd), svc->sock_type, svc->proto, sd);
+	uev_io_init(ctx, &svc->watcher, socket_cb, svc, sd, UEV_READ);
+}
+
+/* Inetd monitor, called by svc_monitor() */
+int inetd_respawn(pid_t pid)
+{
+	svc_t *svc;
+
+	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+		if (SVC_CMD_INETD != svc->type)
+			continue;
+
+		if (svc->pid == pid) {
+			svc->pid = 0;
+			if (!svc->forking)
+				uev_io_set(&svc->watcher, svc->watcher.fd, UEV_READ);
+
+			return 1; /* It was us! */
+		}
+	}
+
+	return 0;		  /* Not an inetd service */
+}
+
+/* Called when changing runlevel to start Inet socket handlers */
+void inetd_runlevel(uev_ctx_t *ctx, int runlevel)
+{
+	svc_t *svc;
+
+	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+		if (SVC_CMD_INETD != svc->type)
+			continue;
+
+		if (!ISSET(svc->runlevels, runlevel))
+			continue;
+
+		
+		spawn_socket(ctx, svc);
+	}
+}
+
+
+/**
+ * Local Variables:
+ *  version-control: t
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */