replace injail perl script with C program

tmcd/freebsd/jail/injail.c

+/*
+ * EMULAB-COPYRIGHT
+ * Copyright (c) 2000-2003 University of Utah and the Flux Group.
+ * All rights reserved.
+ */
+
+/*
+ * The C version of injail.pl
+ *
+ * A much smaller memory footprint.
+ */
+
+#include <unistd.h>
+#include <signal.h>
+#include <stdio.h>
+
+char *vnode;
+char *prog;
+int myuid;
+
+void
+handler(int signo)
+{
+	pid_t killpid = myuid ? 0 : -1;
+
+	signal(SIGUSR1, SIG_IGN);
+	kill(killpid, SIGTERM);
+	sleep(1);
+	kill(killpid, SIGKILL);
+	exit(signo);
+}
+
+void
+usage(void)
+{
+	fprintf(stderr, "%s: [ -v vnodename ] cmd cmdargs ...\n", prog);
+}
+
+char *defargv[] = { "/bin/sh", "/etc/rc", 0 };
+
+int
+main(int argc, char **argv)
+{
+	int ch;
+	pid_t child;
+	extern char **environ;
+
+	prog = argv[0];
+	myuid = getuid();
+
+	while ((ch = getopt(argc, argv, "v:")) != -1)
+		switch(ch) {
+		case 'v':
+			vnode = optarg;
+			break;
+		default:
+			usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+#ifdef __FreeBSD__
+	if (vnode)
+		setproctitle("%s", vnode);
+#endif
+
+	signal(SIGTERM, SIG_IGN);
+	signal(SIGUSR1, handler);
+
+	child = fork();
+	if (child == 0) {
+		signal(SIGTERM, SIG_DFL);
+		if (argc == 0)
+			argv = defargv;
+
+		execve(argv[0], argv, environ);
+		fprintf(stderr, "exec of %s failed\n", argv[0]);
+		_exit(1);
+	}
+
+#if 0
+	/* XXX don't think we want this? */
+	daemon(0, 0);
+#endif
+	(void) waitpid(child, 0, 0);
+
+	/*
+	 * If a command list was provided, we exit.
+	 * Otherwise we wait forever.
+	 */
+	if (argc)
+		handler(0);
+	else {
+		sigset_t mask;
+
+		sigprocmask(0, 0, &mask);
+		while (1)
+			sigsuspend(&mask);
+	}
+	exit(0);
+}

tmcd/freebsd/jail/injail.pl

-#!/usr/bin/perl -w
-#
-# EMULAB-COPYRIGHT
-# Copyright (c) 2000-2003 University of Utah and the Flux Group.
-# All rights reserved.
-#
-use English;
-use Getopt::Std;
-
-#
-# The point of this is to fire up the init code inside the jail,
-# and then wait for a signal from outside the jail. When that happens
-# kill off everything inside the jail and exit. So, like a mini version
-# of /sbin/init, since killing the jail cleanly from outside the jail
-# turns out to be rather difficult, and doing it from inside is very easy!
-#
-# Note though, when the machine is shutdown we can cleanly send this
-# script a signal from mkjail. If reboot is used instead of shutdown,
-# the system broadcasts SIGTERM, and this script will catch that and
-# die. However, thats not good cause the caller (mkjail) wipes out the
-# jail when this script exits of its own accord. So, ignore TERM, and wait
-# for mkjail to send us a USR1, which means to exit.
-#
-my $DEFCONSIX = "/bin/sh /etc/rc";
-
-#
-# Catch TERM.
-# 
-sub handler () {
-    $SIG{USR1} = 'IGNORE';
-    system("kill -TERM -1");
-    sleep(1);
-    system("kill -KILL -1");
-    exit(1);
-}
-$SIG{TERM} = 'IGNORE';
-$SIG{USR1} = \&handler;
-
-my $childpid = fork();
-if (!$childpid) {
-    $SIG{TERM} = 'DEFAULT';
-    
-    if (@ARGV) {
-	exec @ARGV;
-    }
-    else {
-	exec $DEFCONSIX;
-    }
-    die("*** $0:\n".
-	"    exec failed: '@ARGV'\n");
-}
-
-#
-# If a command list was provided, we wait for whatever it was to
-# finish. Otherwise sleep forever. 
-#
-if (@ARGV) {
-    waitpid($childpid, 0);
-    $SIG{TERM} = 'IGNORE';
-    system("kill -TERM -1");
-    sleep(1);
-    system("kill -KILL -1");
-}
-else {
-    #
-    # Otherwise, wait for the command to exit (prevent zombie), but
-    # then just wait forever. The only way to die is to be killed
-    # from outside the jail via the signal handler above. I suppose
-    # we could look at the exit status of the child ...
-    # 
-    waitpid($childpid, 0);
-    while (1) {
-	system("/bin/sleep 10000");
-    }
-}
-exit(0);

tmcd/freebsd/jail/mkjail.pl

@@ -278,8 +278,8 @@ else {
     $SIG{TERM} = 'DEFAULT';
     $ENV{'TMCCVNODEID'} = $vnodeid;
 
-    my $cmd = "jail $jailoptions ".
-	"$JAILPATH/$vnodeid/root $jailhostname $IP /etc/jail/injail.pl";
+    my $cmd = "jail $jailoptions $JAILPATH/$vnodeid/root $jailhostname $IP ".
+	"/etc/jail/injail -v $vnodeid";
     if ($interactive) {
 	$cmd .= " /bin/csh";
     }