hush/procps/kill.c
Denys Vlasenko 5467d268f0 Make killall and killall5 selecatable independent from kill
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2016-11-23 06:43:46 +01:00

324 lines
8.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini kill/killall[5] implementation for busybox
*
* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config KILL
//config: bool "kill"
//config: default y
//config: help
//config: The command kill sends the specified signal to the specified
//config: process or process group. If no signal is specified, the TERM
//config: signal is sent.
//config:
//config:config KILLALL
//config: bool "killall"
//config: default y
//config: help
//config: killall sends a signal to all processes running any of the
//config: specified commands. If no signal name is specified, SIGTERM is
//config: sent.
//config:
//config:config KILLALL5
//config: bool "killall5"
//config: default y
//config: help
//config: The SystemV killall command. killall5 sends a signal
//config: to all processes except kernel threads and the processes
//config: in its own session, so it won't kill the shell that is running
//config: the script it was called from.
//applet:IF_KILL(APPLET(kill, BB_DIR_BIN, BB_SUID_DROP))
//applet:IF_KILLALL(APPLET_ODDNAME(killall, kill, BB_DIR_USR_BIN, BB_SUID_DROP, killall))
//applet:IF_KILLALL5(APPLET_ODDNAME(killall5, kill, BB_DIR_USR_SBIN, BB_SUID_DROP, killall5))
//kbuild:lib-$(CONFIG_KILL) += kill.o
//kbuild:lib-$(CONFIG_KILLALL) += kill.o
//kbuild:lib-$(CONFIG_KILLALL5) += kill.o
//usage:#define kill_trivial_usage
//usage: "[-l] [-SIG] PID..."
//usage:#define kill_full_usage "\n\n"
//usage: "Send a signal (default: TERM) to given PIDs\n"
//usage: "\n -l List all signal names and numbers"
/* //usage: "\n -s SIG Yet another way of specifying SIG" */
//usage:
//usage:#define kill_example_usage
//usage: "$ ps | grep apache\n"
//usage: "252 root root S [apache]\n"
//usage: "263 www-data www-data S [apache]\n"
//usage: "264 www-data www-data S [apache]\n"
//usage: "265 www-data www-data S [apache]\n"
//usage: "266 www-data www-data S [apache]\n"
//usage: "267 www-data www-data S [apache]\n"
//usage: "$ kill 252\n"
//usage:
//usage:#define killall_trivial_usage
//usage: "[-l] [-q] [-SIG] PROCESS_NAME..."
//usage:#define killall_full_usage "\n\n"
//usage: "Send a signal (default: TERM) to given processes\n"
//usage: "\n -l List all signal names and numbers"
/* //usage: "\n -s SIG Yet another way of specifying SIG" */
//usage: "\n -q Don't complain if no processes were killed"
//usage:
//usage:#define killall_example_usage
//usage: "$ killall apache\n"
//usage:
//usage:#define killall5_trivial_usage
//usage: "[-l] [-SIG] [-o PID]..."
//usage:#define killall5_full_usage "\n\n"
//usage: "Send a signal (default: TERM) to all processes outside current session\n"
//usage: "\n -l List all signal names and numbers"
//usage: "\n -o PID Don't signal this PID"
/* //usage: "\n -s SIG Yet another way of specifying SIG" */
#include "libbb.h"
/* Note: kill_main is directly called from shell in order to implement
* kill built-in. Shell substitutes job ids with process groups first.
*
* This brings some complications:
*
* + we can't use xfunc here
* + we can't use applet_name
* + we can't use bb_show_usage
* (Above doesn't apply for killall[5] cases)
*
* kill %n gets translated into kill ' -<process group>' by shell (note space!)
* This is needed to avoid collision with kill -9 ... syntax
*/
int kill_main(int argc UNUSED_PARAM, char **argv)
{
char *arg;
pid_t pid;
int signo = SIGTERM, errors = 0, quiet = 0;
#if ENABLE_KILL && !ENABLE_KILLALL && !ENABLE_KILLALL5
# define killall 0
# define killall5 0
#elif !ENABLE_KILL && ENABLE_KILLALL && !ENABLE_KILLALL5
# define killall 1
# define killall5 0
#elif !ENABLE_KILL && !ENABLE_KILLALL && ENABLE_KILLALL5
# define killall 0
# define killall5 1
#else
/* How to determine who we are? find 3rd char from the end:
* kill, killall, killall5
* ^i ^a ^l - it's unique
* (checking from the start is complicated by /bin/kill... case) */
const char char3 = argv[0][strlen(argv[0]) - 3];
# define killall (ENABLE_KILLALL && char3 == 'a')
# define killall5 (ENABLE_KILLALL5 && char3 == 'l')
#endif
/* Parse any options */
arg = *++argv;
if (!arg || arg[0] != '-') {
goto do_it_now;
}
/* The -l option, which prints out signal names.
* Intended usage in shell:
* echo "Died of SIG`kill -l $?`"
* We try to mimic what kill from coreutils-6.8 does */
if (arg[1] == 'l' && arg[2] == '\0') {
arg = *++argv;
if (!arg) {
/* Print the whole signal list */
print_signames();
return 0;
}
/* -l <sig list> */
do {
if (isdigit(arg[0])) {
signo = bb_strtou(arg, NULL, 10);
if (errno) {
bb_error_msg("unknown signal '%s'", arg);
return EXIT_FAILURE;
}
/* Exitcodes >= 0x80 are to be treated
* as "killed by signal (exitcode & 0x7f)" */
puts(get_signame(signo & 0x7f));
/* TODO: 'bad' signal# - coreutils says:
* kill: 127: invalid signal
* we just print "127" instead */
} else {
signo = get_signum(arg);
if (signo < 0) {
bb_error_msg("unknown signal '%s'", arg);
return EXIT_FAILURE;
}
printf("%d\n", signo);
}
arg = *++argv;
} while (arg);
return EXIT_SUCCESS;
}
/* The -q quiet option */
if (killall && arg[1] == 'q' && arg[2] == '\0') {
quiet = 1;
arg = *++argv;
if (!arg)
bb_show_usage();
if (arg[0] != '-')
goto do_it_now;
}
arg++; /* skip '-' */
/* -o PID? (if present, it always is at the end of command line) */
if (killall5 && arg[0] == 'o')
goto do_it_now;
if (argv[1] && arg[0] == 's' && arg[1] == '\0') { /* -s SIG? */
arg = *++argv;
} /* else it must be -SIG */
signo = get_signum(arg);
if (signo < 0) { /* || signo > MAX_SIGNUM ? */
bb_error_msg("bad signal name '%s'", arg);
return EXIT_FAILURE;
}
arg = *++argv;
do_it_now:
pid = getpid();
if (killall5) {
pid_t sid;
procps_status_t* p = NULL;
/* compat: exitcode 2 is "no one was signaled" */
int ret = 2;
/* Find out our session id */
sid = getsid(pid);
/* Stop all processes */
if (signo != SIGSTOP && signo != SIGCONT)
kill(-1, SIGSTOP);
/* Signal all processes except those in our session */
while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID)) != NULL) {
char **args;
if (p->sid == (unsigned)sid
|| p->sid == 0 /* compat: kernel thread, don't signal it */
|| p->pid == (unsigned)pid
|| p->pid == 1
) {
continue;
}
/* All remaining args must be -o PID options.
* Check p->pid against them. */
args = argv;
while (*args) {
pid_t omit;
arg = *args++;
if (arg[0] != '-' || arg[1] != 'o') {
bb_error_msg("bad option '%s'", arg);
ret = 1;
goto resume;
}
arg += 2;
if (!arg[0] && *args)
arg = *args++;
omit = bb_strtoi(arg, NULL, 10);
if (errno) {
bb_error_msg("invalid number '%s'", arg);
ret = 1;
goto resume;
}
if (p->pid == omit)
goto dont_kill;
}
kill(p->pid, signo);
ret = 0;
dont_kill: ;
}
resume:
/* And let them continue */
if (signo != SIGSTOP && signo != SIGCONT)
kill(-1, SIGCONT);
return ret;
}
/* Pid or name is required for kill/killall */
if (!arg) {
bb_error_msg("you need to specify whom to kill");
return EXIT_FAILURE;
}
if (killall) {
/* Looks like they want to do a killall. Do that */
do {
pid_t* pidList;
pidList = find_pid_by_name(arg);
if (*pidList == 0) {
errors++;
if (!quiet)
bb_error_msg("%s: no process killed", arg);
} else {
pid_t *pl;
for (pl = pidList; *pl; pl++) {
if (*pl == pid)
continue;
if (kill(*pl, signo) == 0)
continue;
errors++;
if (!quiet)
bb_perror_msg("can't kill pid %d", (int)*pl);
}
}
free(pidList);
arg = *++argv;
} while (arg);
return errors;
}
/* Looks like they want to do a kill. Do that */
while (arg) {
#if ENABLE_ASH || ENABLE_HUSH
/*
* We need to support shell's "hack formats" of
* " -PRGP_ID" (yes, with a leading space)
* and " PID1 PID2 PID3" (with degenerate case "")
*/
while (*arg != '\0') {
char *end;
if (*arg == ' ')
arg++;
pid = bb_strtoi(arg, &end, 10);
if (errno && (errno != EINVAL || *end != ' ')) {
bb_error_msg("invalid number '%s'", arg);
errors++;
break;
}
if (kill(pid, signo) != 0) {
bb_perror_msg("can't kill pid %d", (int)pid);
errors++;
}
arg = end; /* can only point to ' ' or '\0' now */
}
#else
pid = bb_strtoi(arg, NULL, 10);
if (errno) {
bb_error_msg("invalid number '%s'", arg);
errors++;
} else if (kill(pid, signo) != 0) {
bb_perror_msg("can't kill pid %d", (int)pid);
errors++;
}
#endif
arg = *++argv;
}
return errors;
}