Date: Mon, 19 Apr 1999 23:06:15 -0400 (EDT) From: stanislav shalunov <shalunov@att.net> To: FreeBSD-gnats-submit@freebsd.org Cc: tony-o@iij.ad.jp, amurai@spec.co.jp Subject: misc/11227: ppp(8) allows mortals to start but not to kill it Message-ID: <199904200306.XAA00794@sharik.worldnet.att.net>
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>Number: 11227
>Category: misc
>Synopsis: ppp(8) allows mortals to start but not to kill it
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Mon Apr 19 20:00:00 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator: stanislav shalunov
>Release: FreeBSD 3.1-RELEASE i386
>Organization:
disorganized
>Environment:
Using user-mode PPP, don't want to give root to my wife. :-)
>Description:
ppp(8) is 4550/root/network and supports ``allow users'' clause, so
it's convenient to give access to non-root users. However, I don't
see any easy way for them to stop the PPP daemon (e.g., to change -auto
to -ddial or just abort -ddial).
It looks like control socket might be useful for this purpose, but I start
ppp -auto when system boots up as root so it might be dangerous...
It's way too complicated anyway: a shell command is desired.
>How-To-Repeat:
>Fix:
Well, here's how I solved my problem. I thought others might benefit from
this or similar approach as well.
# This is a shell archive. Save it in a file, remove anything before
# this line, and then unpack it by entering "sh file". Note, it may
# create directories; files and directories will be owned by you and
# have default permissions.
#
# This archive contains:
#
# pppstop
# pppstop/Makefile
# pppstop/pppstop.c
#
echo c - pppstop
mkdir -p pppstop > /dev/null 2>&1
echo x - pppstop/Makefile
sed 's/^X//' >pppstop/Makefile << 'END-of-pppstop/Makefile'
X# pppstop -- kill running ppp daemon. See pppstop.c for detail.
X# Written by Stanislav Shalunov
X
XBINDIR=/usr/local/sbin
XCFLAGS+=-O6 -s -Wall -pedantic -W
X
Xpppstop: pppstop.c
X ${CC} -o pppstop ${CFLAGS} pppstop.c
X
Xinstall: pppstop
X [ -d ${BINDIR} ] || install -d -o root -g wheel ${BINDIR}
X install -c -s -o root -g network -m 4550 pppstop ${BINDIR}/pppstop
X
Xclean:
X -rm -f pppstop a.out *~ *.o *.a \#* ktrace.out *.core core
END-of-pppstop/Makefile
echo x - pppstop/pppstop.c
sed 's/^X//' >pppstop/pppstop.c << 'END-of-pppstop/pppstop.c'
X/* pppstop -- kill running ppp daemon
X
X Written by Stanislav Shalunov. FreeBSD license applies.
X
X You may need to change PID_FILE definition below depending on how
X many PPP connections you have, but if you have more than one you
X should probably be using something more elaborate.
X
X This program is really slim and safe to be install setuid root.
X You should install it as group network and only allow execution
X by owner and group: chmod 4550 pppstop. Makefile will do this for
X you. */
X
X#include <stdio.h>
X#include <stdlib.h>
X#include <fcntl.h>
X#include <unistd.h>
X#include <signal.h>
X#include <sys/errno.h>
X#include <limits.h>
X
X#define PID_FILE "/var/run/tun0.pid"
X
Xint
Xmain(argc, argv)
X int argc;
X char *argv[];
X{
X int fd, bytes, ppp_pid;
X char buf[16];
X
X if (argc != 1) {
X fprintf(stderr, "Usage: pppstop\n");
X exit(1);
X }
X fd = open(PID_FILE, O_RDONLY);
X if (fd == -1) {
X perror(PID_FILE);
X exit(1);
X }
X bytes = read(fd, buf, sizeof buf - 1);
X if (bytes == -1) {
X perror(PID_FILE);
X exit(1);
X }
X buf[bytes] = '\0';
X /* This can never hurt. */
X buf[(sizeof buf) - 1] = '\0';
X ppp_pid = atoi(buf);
X /* See strtol(3) for explanation of LONG_M{IN,AX} and ERANGE.
X The following condition is redundant--I'm a paranoid maniac. */
X if ((ppp_pid == 0) || (ppp_pid == LONG_MIN) || (ppp_pid == LONG_MAX)
X || (errno == ERANGE)) {
X fprintf(stderr, "pppstop: bad PID value %d\n", ppp_pid);
X exit(1);
X }
X if (kill(ppp_pid, SIGTERM) == -1) {
X perror("kill");
X exit(1);
X }
X /* Give it some time to disconnect. */
X sleep(1);
X if (kill(ppp_pid, 0) == -1) {
X /* It's fast dead. */
X exit(0);
X }
X kill(ppp_pid, SIGHUP);
X sleep(2);
X /* If all *that* didn't help SIGKILL is probably required anyway.
X A manual cleanup of the default route will probably be required
X (if ``add default HISADDR'' was used). */
X kill(ppp_pid, SIGKILL);
X exit(0);
X}
END-of-pppstop/pppstop.c
exit
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