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

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

Makefile

@@ -36,7 +36,7 @@ ARCHIVEZ    = ../$(ARCHIVE).xz
 EXEC        = finit reboot
 HEADERS     = plugin.h svc.h helpers.h queue.h
 DISTFILES   = LICENSE README CHANGELOG finit.conf services
-OBJS        = finit.o conf.o helpers.o sig.o svc.o plugin.o tty.o
+OBJS        = finit.o conf.o helpers.o sig.o svc.o plugin.o tty.o inetd.o
 SRCS        = $(OBJS:.o=.c)
 DEPS        = $(addprefix .,$(SRCS:.c=.d))
 

conf.c

@@ -244,6 +244,12 @@ static int parse_conf(char *file)
 			continue;
 		}
 
+		/* Classic inetd service */
+		if (MATCH_CMD(line, "inetd ", x)) {
+			svc_register(SVC_CMD_INETD, x, NULL);
+			continue;
+		}
+
 		if (MATCH_CMD(line, "console ", x)) {
 			if (console) free(console);
 			console = strdup(strip_line(x));

finit.c

@@ -36,6 +36,7 @@
 #include "sig.h"
 #include "tty.h"
 #include "lite.h"
+#include "inetd.h"
 
 int   debug     = 0;
 int   verbose   = 1;
@@ -251,6 +252,9 @@ int main(int argc, char* argv[])
 	 */
 	svc_runlevel(cfglevel);
 
+	/* Start inetd services */
+	inetd_runlevel(&ctx, runlevel);
+
 	_d("Running svc up hooks ...");
 	plugin_run_hooks(HOOK_SVC_UP);
 

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:
+ */

inetd.h

@@ -0,0 +1,40 @@
+/* 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.
+ */
+
+#ifndef FINIT_INETD_H_
+#define FINIT_INETD_H_
+
+#include "libuev/uev.h"
+
+int  inetd_respawn (pid_t pid);
+void inetd_runlevel(uev_ctx_t *ctx, int runlevel);
+
+#endif	/* FINIT_INETD_H_ */
+
+/**
+ * Local Variables:
+ *  version-control: t
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */

svc.c

@@ -1,7 +1,7 @@
 /* Finit service monitor, task starter and generic API for managing svc_t
  *
  * Copyright (c) 2008-2010  Claudio Matsuoka <cmatsuoka@gmail.com>
- * Copyright (c) 2008-2013  Joachim Nilsson <troglobit@gmail.com>
+ * Copyright (c) 2008-2015  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
@@ -25,6 +25,7 @@
 #include <string.h>
 #include <sys/wait.h>
 #include <utmp.h>
+#include <netdb.h>
 
 #include "finit.h"
 #include "helpers.h"
@@ -33,6 +34,7 @@
 #include "tty.h"
 #include "lite.h"
 #include "svc.h"
+#include "inetd.h"
 
 /* The registered services are kept in shared memory for easy read-only access
  * by 3rd party APIs.  Mostly because of the ability to, from the outside, query
@@ -136,8 +138,12 @@ void svc_bootstrap(void)
 
 	_d("Bootstrapping all services in runlevel S from %s", FINIT_CONF);
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
-		svc_cmd_t cmd = svc_enabled(svc, 0, NULL);
+		svc_cmd_t cmd;
 
+		if (svc->type == SVC_CMD_INETD)
+			continue;
+
+		cmd = svc_enabled(svc, 0, NULL);
 		if (SVC_START == cmd  || (SVC_RELOAD == cmd))
 			svc_start(svc);
 	}
@@ -186,15 +192,19 @@ void svc_runlevel(int newlevel)
 	utmp_save(prevlevel, newlevel);
 
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
-		int run = svc_enabled(svc, 0, NULL);
+		svc_cmd_t cmd;
 
+		if (svc->type == SVC_CMD_INETD)
+			continue;
+
+		cmd = svc_enabled(svc, 0, NULL);
 		if (svc->pid) {
-			if (run == SVC_STOP)
+			if (cmd == SVC_STOP)
 				svc_stop(svc);
-			else if (run == SVC_RELOAD)
+			else if (cmd == SVC_RELOAD)
 				svc_reload(svc);
 		} else {
-			if (run == SVC_START)
+			if (cmd == SVC_START)
 				svc_start(svc);
 		}
 	}
@@ -235,9 +245,10 @@ void svc_runlevel(int newlevel)
  *   "service @username [!0-6,S] /path/to/daemon arg -- Description text"
  *   "task @username [!0-6,S] /path/to/task arg -- Description text"
  *   "run  @username [!0-6,S] /path/to/cmd arg -- Description text"
+ *   "inetd tcp/ssh nowait [2345] @root:root /usr/sbin/sshd -i -- Description"
  *
  * If the username is left out the command is started as root.
-
+ * Inetd services, launched on demand (SVC_CMD_INETD)
  * The [] brackets are there to denote the allowed runlevels. Allowed
  * runlevels mimic that of SysV init with the addition of the 'S'
  * runlevel, which is only run once at startup. It can be seen as the
@@ -249,9 +260,12 @@ void svc_runlevel(int newlevel)
  */
 int svc_register(int type, char *line, char *username)
 {
-	int i = 0;
+	int i = 0, forking = 0;
+	char *service = NULL, *proto = NULL;
 	char *cmd, *desc, *runlevels = NULL;
 	svc_t *svc;
+	struct servent *sv = NULL;
+	struct protoent *pv = NULL;
 
 	if (!line) {
 		_e("Invalid input argument.");
@@ -270,7 +284,13 @@ int svc_register(int type, char *line, char *username)
 	}
 
 	while (cmd) {
-		if (cmd[0] == '@')	/* @username */
+		if (cmd[0] != '/' && strchr(cmd, '/'))
+			service = cmd;   /* inetd port/proto */
+		else if (!strncasecmp(cmd, "nowait", 6))
+			forking = 1;
+		else if (!strncasecmp(cmd, "wait", 4))
+			forking = 0;
+		else if (cmd[0] == '@')	/* @username[:group] */
 			username = &cmd[1];
 		else if (cmd[0] == '[')	/* [runlevels] */
 			runlevels = &cmd[0];
@@ -283,6 +303,24 @@ int svc_register(int type, char *line, char *username)
 			goto incomplete;
 	}
 
+	if (service) {
+		proto = strchr(service, '/');
+		*proto++ = 0;
+		sv = getservbyname(service, proto);
+		if (!sv) {
+			_pe("Invalid inetd %s/%s (service/proto), skipping", service, proto);
+			return errno = EINVAL;
+		}
+
+		pv = getprotobyname(sv->s_proto);
+		if (!pv) {
+			_pe("Cannot find proto %s, skipping.", sv->s_proto);
+			return errno = EINVAL;
+		}
+
+		_d("Got service %s:%d proto %s:%d", service, ntohs(sv->s_port), sv->s_proto, pv->p_proto);
+	}
+
 	svc = svc_new();
 	if (!svc) {
 		_e("Out of memory, cannot register service %s", cmd);
@@ -294,8 +332,29 @@ int svc_register(int type, char *line, char *username)
 	if (desc)
 		strlcpy(svc->desc, desc + 3, sizeof(svc->desc));
 
-	if (username)
+	if (username) {
+		char *ptr = strchr(username, ':');
+
+		if (ptr) {
+			*ptr++ = 0;
+			strlcpy(svc->group, ptr, sizeof(svc->group));
+		}
 		strlcpy(svc->username, username, sizeof(svc->username));
+	}
+
+	if (sv) {
+		strlcpy(svc->service, service, sizeof(svc->service));
+		svc->port  = ntohs(sv->s_port);
+		svc->proto = pv->p_proto;
+
+		/* Naïve mapping tcp->stream, udp->dgram, other->dgram */
+		if (!strcasecmp(sv->s_proto, "tcp"))
+			svc->sock_type = SOCK_STREAM;
+		else
+			svc->sock_type = SOCK_DGRAM;
+
+		svc->forking = forking;
+	}
 
 	strlcpy(svc->cmd, cmd, sizeof(svc->cmd));
 
@@ -355,6 +414,9 @@ static void restart_any_lost_procs(void)
 	svc_t *svc;
 
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
+		if (svc->type == SVC_CMD_INETD)
+			continue;
+
 		if (svc->pid > 0 && pid_alive(svc->pid))
 			continue;
 
@@ -384,6 +446,9 @@ void svc_monitor(pid_t lost)
 	if (tty_respawn(lost))
 		return;
 
+	if (inetd_respawn(lost))
+		return;
+
 	for (svc = svc_iterator(1); svc; svc = svc_iterator(0)) {
 		if (lost != svc->pid)
 			continue;
@@ -420,7 +485,7 @@ void svc_monitor(pid_t lost)
 /* Remember: svc_enabled() must be called before calling svc_start() */
 int svc_start(svc_t *svc)
 {
-	int respawn;
+	int respawn, sd = 0;
 	pid_t pid;
 	sigset_t nmask, omask;
 
@@ -443,6 +508,21 @@ int svc_start(svc_t *svc)
 	if (is_norespawn())
 		return 0;
 
+	if (SVC_CMD_INETD == svc->type) {
+		sd = svc->watcher.fd;
+
+		if (svc->sock_type == SOCK_STREAM) {
+			/* Open new client socket from server socket */
+			sd = accept(sd, NULL, NULL);
+			if (sd < 0) {
+				FLOG_PERROR("Failed accepting inetd service %d/tcp", svc->port);
+				return 0;
+			}
+
+			_d("New client socket %d accepted for inetd service %d/tcp", sd, svc->port);
+		}
+	}
+
 	if (SVC_CMD_SERVICE != svc->type)
 		print_desc("", svc->desc);
 	else if (!respawn)
@@ -478,7 +558,14 @@ int svc_start(svc_t *svc)
 			args[i] = svc->args[i];
 		args[i] = NULL;
 
-		if (debug) {
+		/* Redirect inetd socket to stdin for service */
+		if (SVC_CMD_INETD == svc->type) {
+			/* sd set previously */
+			dup2(sd, STDIN_FILENO);
+			close(sd);
+			dup2(STDIN_FILENO, STDOUT_FILENO);
+			dup2(STDIN_FILENO, STDERR_FILENO);
+		} else if (debug) {
 			int fd;
 			char buf[CMD_SIZE] = "";
 
@@ -507,6 +594,9 @@ int svc_start(svc_t *svc)
 	}
 	svc->pid = pid;
 
+	if (SVC_CMD_INETD == svc->type && svc->sock_type == SOCK_STREAM)
+		close(sd);
+
 	if (SVC_CMD_RUN == svc->type)
 		print_result(WEXITSTATUS(complete(svc->cmd, pid)));
 	else if (!respawn)

svc.h

@@ -1,7 +1,7 @@
 /* Finit service monitor and generic API for managing svc_t structures
  *
  * Copyright (c) 2008-2010  Claudio Matsuoka <cmatsuoka@gmail.com>
- * Copyright (c) 2008-2014  Joachim Nilsson <troglobit@gmail.com>
+ * Copyright (c) 2008-2015  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
@@ -31,6 +31,9 @@
 #include <sys/shm.h>		/* shmat() */
 #include <sys/types.h>		/* pid_t */
 
+#include "queue.h"		/* BSD sys/queue.h API */
+#include "libuev/uev.h"
+
 typedef enum {
 	SVC_STOP = 0,		/* Disabled */
 	SVC_START,		/* Enabled */
@@ -40,7 +43,8 @@ typedef enum {
 typedef enum {
 	SVC_CMD_SERVICE = 0,	/* Monitored, will be respawned */
 	SVC_CMD_TASK,		/* One-shot, runs in parallell */
-	SVC_CMD_RUN		/* Like task, but wait for completion */
+	SVC_CMD_RUN,		/* Like task, but wait for completion */
+	SVC_CMD_INETD		/* Classic inetd service */
 } svc_type_t;
 
 #define FINIT_SHM_ID     0x494E4954  /* "INIT", see ascii(7) */
@@ -59,11 +63,28 @@ typedef struct svc {
 	svc_type_t     type;
 	int	       reload;
 	int	       runlevels;
-	unsigned int   restart_counter; /* Incremented for each restart by service monitor. */
+
+	/* Event loop handler, used for inetd services */
+	uev_t          watcher;
+
+	/* For inetd services */
+	int            sock_type;
+	int            port;
+	int            proto;
+	int            forking;
+	char           service[10];
+
+	/* Incremented for each restart by service monitor. */
+	unsigned int   restart_counter;
+
+	/* Identity */
+	char	       username[MAX_USER_LEN];
+	char	       group[MAX_USER_LEN];
+
+	/* Command, arguments and service description */
 	char	       cmd[MAX_ARG_LEN];
 	char	       args[MAX_NUM_SVC_ARGS][MAX_ARG_LEN];
 	char	       desc[MAX_STR_LEN];
-	char	       username[MAX_USER_LEN];
 
 	/* For external plugins. If @cb is set a plugin is loaded.
 	 * @dynamic:	  Set by plugins that want dynamic events.