On Wed, 2006-02-15 at 15:14 +0100, Javier Fernández-Sanguino Peña wrote: > Hi there. I hope you don't mind me being a little bit picky, but I think it > helps you hone your skills :-)
I've certainly picked up a couple of pointers. > I'm pretty sure there are libraries that do implement that function already. > For exmaple, the 'daemon' package in Debian, which is based on libslack (see > http://libslack.org/) already provides a number of library functions for > daemons, such as daemon_pidfile (see > http://libslack.org/manpages/daemon.3.html). Most of the code you want > is already there (see daemon_construct_pidfile() and > daemon_lock_pidfile() or daemon_pidfile_unlocked) A useful little library indeed, thanks for the pointer. It is very nice and elegant code. It's still not suitable for wholesale inclusion as it has its own memory management routines that are used in daemon_construct_pidfile and daemon_pidfile_unlocked, but I've managed to reuse the daemon_lock_pidfile function with a couple of small wrappers to do the job. The patch is now back down to the size/scope that I consider appropriate for a NMU, I agree that the previous patch was getting a little unwieldy and rough, my apologies. > Would you mind looking up how daemon() does this and maybe implement a > similar solution? Please see the attached patch. Cheers -- Matt Brown [EMAIL PROTECTED] Mob +64 21 611 544 www.mattb.net.nz
diff -ur portreserve-0.0.0/debian/changelog portreserve-0.0.0-matt/debian/changelog
--- portreserve-0.0.0/debian/changelog 2006-02-12 11:07:31.000000000 +0000
+++ portreserve-0.0.0-matt/debian/changelog 2006-02-16 08:42:01.000000000 +0000
@@ -1,3 +1,15 @@
+portreserve (0.0.0-2.1) unstable; urgency=low
+
+ * Non-maintainer upload
+ * Fixed minor init script bugs (Closes: #352103)
+ - Use -z instead of -n to test list of service files
+ - Use $NAME instead of the undefined $prog in the pidfile name
+ * Reworked portreserve pidfile handling
+ - Utilise functions from libslack to safely create and lock pidfile
+ - Remove pidfile when program exits cleanly
+
+ -- Matt Brown <[EMAIL PROTECTED]> Thu, 16 Feb 2006 21:41:33 +1300
+
portreserve (0.0.0-2) unstable; urgency=low
* Added xmlto to Build-Depends (Closes: #337848)
diff -ur portreserve-0.0.0/debian/portreserve.init portreserve-0.0.0-matt/debian/portreserve.init
--- portreserve-0.0.0/debian/portreserve.init 2006-02-12 11:07:31.000000000 +0000
+++ portreserve-0.0.0-matt/debian/portreserve.init 2006-02-15 11:43:34.000000000 +0000
@@ -11,7 +11,7 @@
test -f $DAEMON || exit 0
NAME=`basename $DAEMON`
-PIDFILE=/var/run/$prog.pid
+PIDFILE=/var/run/$NAME.pid
running()
{
@@ -22,8 +22,8 @@
# No pid, probably no daemon present
[ -z "$pid" ] && return 1
[ ! -d /proc/$pid ] && return 1
- cmd=`cat /proc/$pid/cmdline | tr "\000" "\n"|head -n 1 |cut -d : -f 1`
-
+ cmdline=`cat /proc/$pid/cmdline | tr "\000" "\n"|head -n 1 |cut -d : -f 1`
+ cmd=`basename $cmdline`
[ "$cmd" != "$NAME" ] && return 1
return 0
}
@@ -36,7 +36,7 @@
if [ ! -d /etc/portreserve ] ; then
return 1
fi
- if [ -n "`find /etc/portreserve \! -name "*~" -a \! -name "*.*" -type f`" ] ; then
+ if [ -z "`find /etc/portreserve \! -name "*~" -a \! -name "*.*" -type f`" ] ; then
return 1
fi
return 0
Only in portreserve-0.0.0-matt/: .deps
Only in portreserve-0.0.0: portreserve.spec
diff -ur portreserve-0.0.0/src/portreserve.c portreserve-0.0.0-matt/src/portreserve.c
--- portreserve-0.0.0/src/portreserve.c 2003-09-03 14:12:52.000000000 +0000
+++ portreserve-0.0.0-matt/src/portreserve.c 2006-02-16 08:34:09.000000000 +0000
@@ -64,7 +64,13 @@
# include <unistd.h>
#endif
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
#define UNIX_SOCKET "/var/run/portreserve/socket"
+#define PIDFILE "/var/run/portreserve.pid"
struct map {
struct map *next;
@@ -264,9 +270,85 @@
return 0;
}
+/* daemon_lock_pidfile and fcntl_lock taken from libslack
+ * Copyright (C) 1999-2004 raf <[EMAIL PROTECTED]>
+ * Licensed under the GPL
+ */
+int
+fcntl_lock(int fd, int cmd, int type, int whence, int start, int len)
+{
+ struct flock lock[1];
+
+ lock->l_type = type;
+ lock->l_whence = whence;
+ lock->l_start = start;
+ lock->l_len = len;
+
+ return fcntl(fd, cmd, lock);
+}
+
+static int
+daemon_lock_pidfile(char *pidfile)
+{
+ mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
+ int pid_fd;
+
+ /* This is broken over NFS (Linux). So pidfiles must reside locally. */
+
+ if ((pid_fd = open(pidfile, O_RDWR | O_CREAT | O_EXCL, mode)) == -1)
+ {
+ if (errno != EEXIST)
+ return -1;
+
+ /*
+ ** The pidfile already exists. Is it locked?
+ ** If so, another invocation is still alive.
+ ** If not, the invocation that created it has died.
+ ** Open the pidfile to attempt a lock.
+ */
+
+ if ((pid_fd = open(pidfile, O_RDWR)) == -1)
+ return -1;
+ }
+
+ if (fcntl_lock(pid_fd, F_SETLK, F_WRLCK, SEEK_SET, 0, 0) == -1)
+ return -1;
+
+ return pid_fd;
+}
+
+int
+create_pidfile(char *pidfile)
+{
+
+ int fd;
+ char pid[32];
+
+ /* Open and lock pidfile */
+ if ((fd = daemon_lock_pidfile(pidfile)) == -1) {
+ return -1;
+ }
+
+ /* Store our pid */
+ snprintf(pid, sizeof(pid), "%d\n", (int)getpid());
+ if (write(fd, pid, strlen(pid)) != strlen(pid)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+void
+handle_sigterm (int sig)
+{
+ unlink(PIDFILE);
+ exit(0);
+}
+
int
main (int argc, char **argv)
{
+ int rv;
const char *p = strrchr (argv[0], '/');
if (!p++)
p = argv[0];
@@ -278,7 +360,9 @@
r += portrelease (argv[i]);
return r;
}
-
+
+ signal (SIGTERM, handle_sigterm);
+
if (argc > 1) {
if (!strcmp (argv[1], "-d"))
debug = 1;
@@ -302,7 +386,12 @@
close (STDOUT_FILENO);
close (STDERR_FILENO);
setsid ();
+ if (create_pidfile(PIDFILE)==-1)
+ error (EXIT_FAILURE, errno,
+ "Failed to write pidfile!");
}
- return portreserve ();
+ rv = portreserve();
+ unlink(PIDFILE);
+ return rv;
}
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