1 files changed, 374 insertions, 0 deletions
diff --git a/liblock/lockdaemon.c b/liblock/lockdaemon.c
new file mode 100644
index 0000000..af0027b
--- /dev/null
+++ b/liblock/lockdaemon.c
@@ -0,0 +1,374 @@
+/*
+** Copyright 2000-2007 Double Precision, Inc.  See COPYING for
+** distribution information.
+*/
+
+#include	"config.h"
+#include	"liblock.h"
+#include	<stdio.h>
+#include	<signal.h>
+#include	<limits.h>
+#include	<stdlib.h>
+#include	<string.h>
+#include	<unistd.h>
+#include	<ctype.h>
+#include	<errno.h>
+#if	HAVE_FCNTL_H
+#include	<fcntl.h>
+#endif
+#include	<sys/types.h>
+#include	"../numlib/numlib.h"
+#if HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+#ifndef WEXITSTATUS
+#define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
+#endif
+#ifndef WIFEXITED
+#define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+#if	HAVE_SYS_IOCTL_H
+#include	<sys/ioctl.h>
+#endif
+
+#define exit(_a_) _exit(_a_)
+
+
+static int start1(const char *, int);
+
+#define CONSOLE "/dev/null"
+
+int ll_daemon_start(const char *lockfile)
+{
+pid_t	p;
+int	pipefd[2];
+char	c;
+int	i;
+
+	/*
+	** Close any open file descriptors.
+	*/
+
+	for (i=3; i < 256; i++)
+		close(i);
+
+	/*
+	** We fork, and set up a pipe from the child process.  If we read
+	** a single 0 byte from the pipe, it means that the child has
+	** successfully initialized, and will return to main, so we exit(0).
+	** If we do not read a single 0 byte from the pipe, it means that
+	** there was an initialization error, so we return -1 to main.
+	*/
+
+	if (pipe(pipefd) < 0)
+	{
+		perror("pipe");
+		return (-1);
+	}
+
+	if ((p=fork()) == -1)
+	{
+		close(pipefd[0]);
+		close(pipefd[1]);
+		perror("fork");
+		return (-1);
+	}
+
+	if (p == 0)
+	{
+		close(pipefd[0]);
+
+		/*
+		** We fork once more, so that the daemon process will not
+		** be the child process of anyone.
+		*/
+
+		p=fork();
+		if (p == -1)
+		{
+			perror("fork");
+			exit(0);
+		}
+		if (p)
+			exit(0);
+
+		/*
+		** Continue initialization in start1()
+		*/
+		return (start1(lockfile, pipefd[1]));
+	}
+
+	close(pipefd[1]);
+	if (read(pipefd[0], &c, 1) <= 0)
+		c=1;
+	close(pipefd[0]);
+	if (c == 0)
+		exit (0);	/* Successful start of daemon */
+	errno=EAGAIN;
+	return (-1);
+}
+
+static int start1(const char *lockfile, int fd)
+{
+int	lockfd, maxfd;
+
+#if     HAVE_SETPGRP
+#if     SETPGRP_VOID
+	setpgrp();
+#else
+	setpgrp(0, 0);
+#endif
+#endif
+#ifdef  TIOCNOTTY
+
+	{
+	int fd=open("/dev/tty", O_RDWR);
+
+		if (fd >= 0)
+		{
+			ioctl(fd, TIOCNOTTY, 0);
+			close(fd);
+		}
+	}
+#endif
+
+
+	/* Attempt to obtain a lock */
+
+	lockfd=open(lockfile, O_RDWR|O_CREAT, 0600);
+
+	if (lockfd < 0)
+	{
+		/* Perhaps an upgraded daemon runs under new uid? */
+
+		unlink(lockfile);
+		lockfd=open(lockfile, O_RDWR|O_CREAT, 0600);
+	}
+
+#if HAVE_GETDTABLESIZE
+	maxfd=getdtablesize()-1;
+#elif defined(OPEN_MAX)
+	maxfd=OPEN_MAX-1;
+#elif HAVE_SYSCONF && defined(_SC_OPEN_MAX)
+	if ((maxfd=sysconf(_SC_OPEN_MAX)) < 0)
+		maxfd=63;
+	else if (maxfd > 0)
+		maxfd--;
+#else
+	maxfd=63;
+#endif
+
+	if (lockfd < 0 || dup2(lockfd, maxfd) != maxfd)
+	{
+		perror(lockfile);
+		exit(1);
+	}
+
+	close(lockfd);
+	lockfd=maxfd;
+
+#ifdef	FD_CLOEXEC
+	if (fcntl(lockfd, F_SETFD, FD_CLOEXEC) < 0)
+	{
+		perror("fcntl");
+		close(lockfd);
+		exit(1);
+	}
+#endif
+
+	if (ll_lock_ex_test(lockfd))
+	{
+		if (write(fd, "", 1) != 1)
+			exit(1); /* Shouldn't happen */
+
+		close(fd);
+		exit (0);	/* Already running, pretend success */
+	}
+
+	/*
+	** Return >0 to main, so it can continue main's setup.
+	*/
+
+	return (fd);
+}
+
+int ll_daemon_resetio()
+{
+int	i;
+
+	close(0);
+	if (open("/dev/null", O_RDONLY) != 0)
+		return (-1);
+
+	close(1);
+	i=open(CONSOLE, O_WRONLY);
+	if (i < 0)	i=open("/dev/null", O_WRONLY);
+	if (i != 1)	return (-1);
+
+	close(2);
+	i=open(CONSOLE, O_WRONLY);
+	if (i < 0)	i=open("/dev/null", O_WRONLY);
+	if (i != 2)	return (-1);
+	return (0);
+}
+
+void ll_daemon_started(const char *pidfile, int fd)
+{
+char	buf[NUMBUFSIZE+1];
+char	*p=strcat(libmail_str_pid_t(getpid(), buf), "\n");
+FILE	*fp;
+
+	unlink(pidfile); 
+	if ((fp=fopen(pidfile, "w")) == NULL ||
+		fprintf(fp, "%s", p) < 0 || fflush(fp) < 0 || fclose(fp))
+	{
+		perror(pidfile);
+		exit(1);
+	}
+
+	if (write(fd, "", 1) != 1)	/* Signal waiting parent */
+		exit(1); /* Shouldn't happen */
+	close(fd);
+}
+
+static void stop1(const char *, const char *);
+
+int ll_daemon_stop(const char *lockfile, const char *pidfile)
+{
+pid_t	p, p2;
+int	waitstat;
+
+	/*
+	** We fork, and the child process attempts to stop the daemon,
+	** then communicates the success to us, via its exit code.
+	*/
+
+	signal(SIGCHLD, SIG_DFL);
+	if ((p=fork()) == -1)
+	{
+		perror("fork");
+		return (1);
+	}
+	if (p == 0)	stop1(lockfile, pidfile);
+
+	while ((p2=wait(&waitstat)) != p)
+		;
+
+	if (WIFEXITED(waitstat))
+		return (WEXITSTATUS(waitstat));
+	return (0);
+}
+
+/*
+**	The child process forks too.  The parent process goes in a loop,
+**	trying to kill the daemon process.
+**
+**	The child process attempts to lock the lock file.  When it
+**	succeeds, it exits.  When the child process exits, the parent
+**	process kills itself.
+*/
+
+static RETSIGTYPE sigexit(int signum)
+{
+	kill(getpid(), SIGKILL);
+#if     RETSIGTYPE != void
+	return (0);
+#endif
+}
+
+static void stop1(const char *lockfile, const char *pidfile)
+{
+int	lockfd;
+pid_t	p;
+
+	if ((lockfd=open(lockfile, O_RDWR|O_CREAT, 0600)) < 0)
+	{
+		perror(lockfile);
+		exit(1);
+	}
+
+	if ( ll_lock_ex_test(lockfd) == 0)	/* No daemon process running */
+	{
+		close(lockfd);
+		exit (0);	/* That was easy! */
+	}
+
+	signal(SIGCHLD, sigexit);
+
+	if ((p=fork()) == -1)
+	{
+		perror("fork");
+		exit(1);
+	}
+
+	if (p)	/* Parent - first sends a SIGTERM, then a SIGKILL */
+	{
+	int	signum=SIGTERM;
+
+		close(lockfd);
+		for (;; sleep(10))
+		{
+		FILE	*fp;
+		int	c;
+
+			if ((fp=fopen(pidfile, "r")) == NULL)
+				continue;
+
+			p=0;
+
+			while ((c=getc(fp)) != EOF && c != '\n')
+			{
+				if (isdigit(c))
+					p=p*10+(c-'0');
+			}
+
+			fclose(fp);
+			if (p)
+				kill(p, signum);
+			signum=SIGKILL;
+		}
+	}
+
+	if (ll_lock_ex(lockfd))
+		perror("lock");
+	close(lockfd);
+	exit(0);
+}
+
+int ll_daemon_restart(const char *lockfile, const char *pidfile)
+{
+int	lockfd;
+pid_t	p;
+FILE	*fp;
+int	c;
+
+	if ((lockfd=open(lockfile, O_RDWR|O_CREAT, 0600)) < 0)
+	{
+		perror(lockfile);
+		return (1);
+	}
+
+	if ( ll_lock_ex_test(lockfd) == 0)	/* No daemon process running */
+	{
+		close(lockfd);
+		return (0);	/* That was easy! */
+	}
+	close(lockfd);
+
+	if ((fp=fopen(pidfile, "r")) == NULL)
+		return (0);
+
+	p=0;
+
+	while ((c=getc(fp)) != EOF && c != '\n')
+	{
+		if (isdigit(c))
+			p=p*10+(c-'0');
+	}
+
+	fclose(fp);
+	if (p)
+		kill(p, SIGHUP);
+	return (0);
+}
+