procps/skill.c
Craig Small 07642b8ea6 kill: report error if cannot kill process
Shell kill would report a problem if you tried to kill a process
while procps kill was silent. This meant it looked like kill worked
when it actually failed.

References:
 https://bugs.debian.org/733172
2016-07-02 12:25:14 +10:00

760 lines
18 KiB
C

/*
* skill.c - send a signal to process
* Copyright 1998-2002 by Albert Cahalan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include "c.h"
#include "fileutils.h"
#include "nsutils.h"
#include "strutils.h"
#include "nls.h"
#include "xalloc.h"
#include "proc/pwcache.h"
#include "proc/sig.h"
#include "proc/devname.h"
#include "proc/procps.h" /* char *user_from_uid(uid_t uid) */
#include "proc/readproc.h"
#include "proc/version.h" /* procps_version */
#include "rpmatch.h"
#define DEFAULT_NICE 4
struct run_time_conf_t {
int fast;
int interactive;
int verbose;
int warnings;
int noaction;
int debugging;
};
static int tty_count, uid_count, cmd_count, pid_count, namespace_count;
static int *ttys;
static uid_t *uids;
static const char **cmds;
static int *pids;
static char **namespaces;
static int ns_pid;
static proc_t ns_task;
#define ENLIST(thing,addme) do{ \
if(!thing##s) thing##s = xmalloc(sizeof(*thing##s)*saved_argc); \
thing##s[thing##_count++] = addme; \
}while(0)
static int my_pid;
static int saved_argc;
static int sig_or_pri;
enum {
PROG_UNKNOWN,
PROG_KILL,
PROG_SKILL,
PROG_SNICE
};
static int program = PROG_UNKNOWN;
static void display_kill_version(void)
{
fprintf(stdout, PROCPS_NG_VERSION);
}
static int ns_flags = 0x3f;
static int parse_namespaces(char *optarg)
{
char *ptr = optarg, *tmp;
int len, id;
ns_flags = 0;
while (1) {
if (strchr(ptr, ',') == NULL) {
len = -1;
tmp = strdup(ptr);
} else {
len = strchr(ptr, ',') - ptr;
tmp = strndup(ptr, len);
}
id = get_ns_id(tmp);
if (id == -1) {
fprintf(stderr, "%s is not a valid namespace\n", tmp);
free(tmp);
return 1;
}
ns_flags |= (1 << id);
ENLIST(namespace, tmp);
if (len == -1)
break;
ptr+= len + 1;
}
return 0;
}
/* kill or nice a process */
static void hurt_proc(int tty, int uid, int pid, const char *restrict const cmd,
struct run_time_conf_t *run_time)
{
int failed;
char dn_buf[1000];
dev_to_tty(dn_buf, 999, tty, pid, ABBREV_DEV);
if (run_time->interactive) {
char *buf;
size_t len = 0;
fprintf(stderr, "%-8s %-8s %5d %-16.16s ? ",
(char *)dn_buf, user_from_uid(uid), pid, cmd);
fflush (stdout);
if (getline(&buf, &len, stdin) == -1)
return;
if (rpmatch(buf) < 1) {
free(buf);
return;
}
free(buf);
}
/* do the actual work */
errno = 0;
if (program == PROG_SKILL)
failed = kill(pid, sig_or_pri);
else
failed = setpriority(PRIO_PROCESS, pid, sig_or_pri);
if ((run_time->warnings && failed) || run_time->debugging || run_time->verbose) {
fprintf(stderr, "%-8s %-8s %5d %-16.16s ",
(char *)dn_buf, user_from_uid(uid), pid, cmd);
perror("");
return;
}
if (run_time->interactive)
return;
if (run_time->noaction) {
printf("%d\n", pid);
return;
}
}
/* check one process */
static void check_proc(int pid, struct run_time_conf_t *run_time)
{
char buf[128];
struct stat statbuf;
proc_t task;
char *tmp;
int tty;
int fd;
int i;
if (pid == my_pid || pid == 0)
return;
/* pid (cmd) state ppid pgrp session tty */
sprintf(buf, "/proc/%d/stat", pid);
fd = open(buf, O_RDONLY);
if (fd == -1) {
/* process exited maybe */
if (run_time->warnings)
xwarn(_("cannot open file %s"), buf);
return;
}
fstat(fd, &statbuf);
if (uids) {
/* check the EUID */
i = uid_count;
while (i--)
if (uids[i] == statbuf.st_uid)
break;
if (i == -1)
goto closure;
}
if (read(fd, buf, 128) <= 0)
goto closure;
buf[127] = '\0';
tmp = strrchr(buf, ')');
*tmp++ = '\0';
i = 5;
while (i--)
while (*tmp++ != ' ')
/* scan to find tty */ ;
tty = atoi(tmp);
if (ttys) {
i = tty_count;
while (i--)
if (ttys[i] == tty)
break;
if (i == -1)
goto closure;
}
tmp = strchr(buf, '(') + 1;
if (cmds) {
i = cmd_count;
/* fast comparison trick -- useful? */
while (i--)
if (cmds[i][0] == *tmp && !strcmp(cmds[i], tmp))
break;
if (i == -1)
goto closure;
}
if (ns_pid) {
if (ns_read(pid, &task))
goto closure;
for (i = 0; i < NUM_NS; i++) {
if (ns_flags & (1 << i)) {
if (task.ns[i] != ns_task.ns[i])
goto closure;
}
}
}
/* This is where we kill/nice something. */
/* for debugging purposes?
fprintf(stderr, "PID %d, UID %d, TTY %d,%d, COMM %s\n",
pid, statbuf.st_uid, tty >> 8, tty & 0xf, tmp);
*/
hurt_proc(tty, statbuf.st_uid, pid, tmp, run_time);
closure:
/* kill/nice _first_ to avoid PID reuse */
close(fd);
}
/* debug function */
static void show_lists(void)
{
int i;
fprintf(stderr, "signal: %d\n", sig_or_pri);
fprintf(stderr, "%d TTY: ", tty_count);
if (ttys) {
i = tty_count;
while (i--) {
fprintf(stderr, "%d,%d%c", (ttys[i] >> 8) & 0xff,
ttys[i] & 0xff, i ? ' ' : '\n');
}
} else
fprintf(stderr, "\n");
fprintf(stderr, "%d UID: ", uid_count);
if (uids) {
i = uid_count;
while (i--)
fprintf(stderr, "%d%c", uids[i], i ? ' ' : '\n');
} else
fprintf(stderr, "\n");
fprintf(stderr, "%d PID: ", pid_count);
if (pids) {
i = pid_count;
while (i--)
fprintf(stderr, "%d%c", pids[i], i ? ' ' : '\n');
} else
fprintf(stderr, "\n");
fprintf(stderr, "%d CMD: ", cmd_count);
if (cmds) {
i = cmd_count;
while (i--)
fprintf(stderr, "%s%c", cmds[i], i ? ' ' : '\n');
} else
fprintf(stderr, "\n");
}
/* iterate over all PIDs */
static void iterate(struct run_time_conf_t *run_time)
{
int pid;
DIR *d;
struct dirent *de;
if (pids) {
pid = pid_count;
while (pid--)
check_proc(pids[pid], run_time);
return;
}
#if 0
/* could setuid() and kill -1 to have the kernel wipe out a user */
if (!ttys && !cmds && !pids && !run_time->interactive) {
}
#endif
d = opendir("/proc");
if (!d)
xerr(EXIT_FAILURE, "/proc");
while ((de = readdir(d))) {
if (de->d_name[0] > '9')
continue;
if (de->d_name[0] < '1')
continue;
pid = atoi(de->d_name);
if (pid)
check_proc(pid, run_time);
}
closedir(d);
}
/* kill help */
static void __attribute__ ((__noreturn__)) kill_usage(FILE * out)
{
fputs(USAGE_HEADER, out);
fprintf(out,
_(" %s [options] <pid> [...]\n"), program_invocation_short_name);
fputs(USAGE_OPTIONS, out);
fputs(_(" <pid> [...] send signal to every <pid> listed\n"), out);
fputs(_(" -<signal>, -s, --signal <signal>\n"
" specify the <signal> to be sent\n"), out);
fputs(_(" -l, --list=[<signal>] list all signal names, or convert one to a name\n"), out);
fputs(_(" -L, --table list all signal names in a nice table\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_HELP, out);
fputs(USAGE_VERSION, out);
fprintf(out, USAGE_MAN_TAIL("kill(1)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
/* skill and snice help */
static void __attribute__ ((__noreturn__)) skillsnice_usage(FILE * out)
{
fputs(USAGE_HEADER, out);
if (program == PROG_SKILL) {
fprintf(out,
_(" %s [signal] [options] <expression>\n"),
program_invocation_short_name);
} else {
fprintf(out,
_(" %s [new priority] [options] <expression>\n"),
program_invocation_short_name);
}
fputs(USAGE_OPTIONS, out);
fputs(_(" -f, --fast fast mode (not implemented)\n"), out);
fputs(_(" -i, --interactive interactive\n"), out);
fputs(_(" -l, --list list all signal names\n"), out);
fputs(_(" -L, --table list all signal names in a nice table\n"), out);
fputs(_(" -n, --no-action do not actually kill processes; just print what would happen\n"), out);
fputs(_(" -v, --verbose explain what is being done\n"), out);
fputs(_(" -w, --warnings enable warnings (not implemented)\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(_("Expression can be: terminal, user, pid, command.\n"
"The options below may be used to ensure correct interpretation.\n"), out);
fputs(_(" -c, --command <command> expression is a command name\n"), out);
fputs(_(" -p, --pid <pid> expression is a process id number\n"), out);
fputs(_(" -t, --tty <tty> expression is a terminal\n"), out);
fputs(_(" -u, --user <username> expression is a username\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(_("Alternatively, expression can be:\n"), out);
fputs(_(" --ns <pid> match the processes that belong to the same\n"
" namespace as <pid>\n"), out);
fputs(_(" --nslist <ns,...> list which namespaces will be considered for\n"
" the --ns option; available namespaces are\n:"
" ipc, mnt, net, pid, user, uts\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_HELP, out);
fputs(USAGE_VERSION, out);
if (program == PROG_SKILL) {
fprintf(out,
_("\n"
"The default signal is TERM. Use -l or -L to list available signals.\n"
"Particularly useful signals include HUP, INT, KILL, STOP, CONT, and 0.\n"
"Alternate signals may be specified in three ways: -SIGKILL -KILL -9\n"));
fprintf(out, USAGE_MAN_TAIL("skill(1)"));
} else {
fprintf(out,
_("\n"
"The default priority is +4. (snice +4 ...)\n"
"Priority numbers range from +20 (slowest) to -20 (fastest).\n"
"Negative priority numbers are restricted to administrative users.\n"));
fprintf(out, USAGE_MAN_TAIL("snice(1)"));
}
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
static int skill_sig_option(int *argc, char **argv)
{
int i;
int signo = -1;
for (i = 1; i < *argc; i++) {
if (argv[i][0] == '-') {
signo = signal_name_to_number(argv[i] + 1);
if (-1 < signo) {
memmove(argv + i, argv + i + 1,
sizeof(char *) * (*argc - i));
(*argc)--;
return signo;
}
}
}
return signo;
}
/* kill */
static void __attribute__ ((__noreturn__))
kill_main(int argc, char **argv)
{
int signo, i;
int loop = 1;
long pid;
int exitvalue = EXIT_SUCCESS;
static const struct option longopts[] = {
{"list", optional_argument, NULL, 'l'},
{"table", no_argument, NULL, 'L'},
{"signal", required_argument, NULL, 's'},
{"help", no_argument, NULL, 'h'},
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
setlocale (LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
atexit(close_stdout);
if (argc < 2)
kill_usage(stderr);
signo = skill_sig_option(&argc, argv);
if (signo < 0)
signo = SIGTERM;
opterr=0; /* suppress errors on -123 */
while (loop == 1 && (i = getopt_long(argc, argv, "l::Ls:hV", longopts, NULL)) != -1)
switch (i) {
case 'l':
if (optarg) {
char *s;
s = strtosig(optarg);
if (s)
printf("%s\n", s);
else
xwarnx(_("unknown signal name %s"),
optarg);
free(s);
} else {
unix_print_signals();
}
exit(EXIT_SUCCESS);
case 'L':
pretty_print_signals();
exit(EXIT_SUCCESS);
case 's':
signo = signal_name_to_number(optarg);
break;
case 'h':
kill_usage(stdout);
case 'V':
display_kill_version();
exit(EXIT_SUCCESS);
case '?':
if (!isdigit(optopt)) {
xwarnx(_("invalid argument %c"), optopt);
kill_usage(stderr);
} else {
/* Special case for signal digit negative
* PIDs */
pid = atoi(argv[optind]);
if (kill((pid_t)pid, signo) != 0)
exitvalue = EXIT_FAILURE;
exit(exitvalue);
}
loop=0;
break;
default:
kill_usage(stderr);
}
argc -= optind;
argv += optind;
if (argc < 1)
kill_usage(stderr);
for (i = 0; i < argc; i++) {
pid = strtol_or_err(argv[i], _("failed to parse argument"));
if (!kill((pid_t) pid, signo))
continue;
error(0, errno, "(%d)", pid);
exitvalue = EXIT_FAILURE;
continue;
}
exit(exitvalue);
}
#if 0
static void _skillsnice_usage(int line)
{
fprintf(stderr, _("something at line %d\n"), line);
skillsnice_usage(stderr);
}
#define skillsnice_usage() _skillsnice_usage(__LINE__)
#endif
#define NEXTARG (argc?( argc--, ((argptr=*++argv)) ):NULL)
/* common skill/snice argument parsing code */
static int snice_prio_option(int *argc, char **argv)
{
int i = 1, nargs = *argc;
long prio = DEFAULT_NICE;
while (i < nargs) {
if ((argv[i][0] == '-' || argv[i][0] == '+')
&& isdigit(argv[i][1])) {
prio = strtol_or_err(argv[i],
_("failed to parse argument"));
if (prio < INT_MIN || INT_MAX < prio)
xerrx(EXIT_FAILURE,
_("priority %lu out of range"), prio);
nargs--;
if (nargs - i)
memmove(argv + i, argv + i + 1,
sizeof(char *) * (nargs - i));
} else
i++;
}
*argc = nargs;
return (int)prio;
}
static void skillsnice_parse(int argc,
char **argv, struct run_time_conf_t *run_time)
{
int signo = -1;
int prino = DEFAULT_NICE;
int ch, i;
enum {
NS_OPTION = CHAR_MAX + 1,
NSLIST_OPTION,
};
static const struct option longopts[] = {
{"command", required_argument, NULL, 'c'},
{"debug", no_argument, NULL, 'd'},
{"fast", no_argument, NULL, 'f'},
{"interactive", no_argument, NULL, 'i'},
{"list", no_argument, NULL, 'l'},
{"no-action", no_argument, NULL, 'n'},
{"pid", required_argument, NULL, 'p'},
{"table", no_argument, NULL, 'L'},
{"tty", required_argument, NULL, 't'},
{"user", required_argument, NULL, 'u'},
{"ns", required_argument, NULL, NS_OPTION},
{"nslist", required_argument, NULL, NSLIST_OPTION},
{"verbose", no_argument, NULL, 'v'},
{"warnings", no_argument, NULL, 'w'},
{"help", no_argument, NULL, 'h'},
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
if (argc < 2)
skillsnice_usage(stderr);
sig_or_pri = -1;
if (program == PROG_SNICE)
prino = snice_prio_option(&argc, argv);
else if (program == PROG_SKILL) {
signo = skill_sig_option(&argc, argv);
if (-1 < signo)
sig_or_pri = signo;
}
pid_count = 0;
while ((ch =
getopt_long(argc, argv, "c:dfilnp:Lt:u:vwhV", longopts,
NULL)) != -1)
switch (ch) {
case 'c':
ENLIST(cmd, optarg);
break;
case 'd':
run_time->debugging = 1;
break;
case 'f':
run_time->fast = 1;
break;
case 'i':
run_time->interactive = 1;
break;
case 'l':
unix_print_signals();
exit(EXIT_SUCCESS);
case 'n':
run_time->noaction = 1;
break;
case 'p':
ENLIST(pid,
strtol_or_err(optarg,
_("failed to parse argument")));
pid_count++;
break;
case 'L':
pretty_print_signals();
exit(EXIT_SUCCESS);
case 't':
{
struct stat sbuf;
char path[32];
snprintf(path, 32, "/dev/%s", optarg);
if (stat(path, &sbuf) >= 0
&& S_ISCHR(sbuf.st_mode)) {
ENLIST(tty, sbuf.st_rdev);
}
}
break;
case 'u':
{
struct passwd *passwd_data;
passwd_data = getpwnam(optarg);
if (passwd_data) {
ENLIST(uid, passwd_data->pw_uid);
}
}
break;
case NS_OPTION:
ns_pid = atoi(optarg);
if (ns_pid == 0) {
xwarnx(_("invalid pid number %s"), optarg);
kill_usage(stderr);
}
if (ns_read(ns_pid, &ns_task)) {
xwarnx(_("error reading reference namespace "
"information"));
kill_usage(stderr);
}
break;
case NSLIST_OPTION:
if (parse_namespaces(optarg)) {
xwarnx(_("invalid namespace list"));
kill_usage(stderr);
}
break;
case 'v':
run_time->verbose = 1;
break;
case 'w':
run_time->warnings = 1;
break;
case 'h':
skillsnice_usage(stdout);
case 'V':
display_kill_version();
exit(EXIT_SUCCESS);
default:
skillsnice_usage(stderr);
}
argc -= optind;
argv += optind;
for (i = 0; i < argc; i++) {
long num;
char *end = NULL;
errno = 0;
num = strtol(argv[0], &end, 10);
if (errno == 0 && argv[0] != end && end != NULL && *end == '\0') {
ENLIST(pid, num);
pid_count++;
} else {
ENLIST(cmd, argv[0]);
}
argv++;
}
/* No more arguments to process. Must sanity check. */
if (!tty_count && !uid_count && !cmd_count && !pid_count && !ns_pid)
xerrx(EXIT_FAILURE, _("no process selection criteria"));
if ((run_time->fast | run_time->interactive | run_time->
verbose | run_time->warnings | run_time->noaction) & ~1)
xerrx(EXIT_FAILURE, _("general flags may not be repeated"));
if (run_time->interactive
&& (run_time->verbose | run_time->fast | run_time->noaction))
xerrx(EXIT_FAILURE, _("-i makes no sense with -v, -f, and -n"));
if (run_time->verbose && (run_time->interactive | run_time->fast))
xerrx(EXIT_FAILURE, _("-v makes no sense with -i and -f"));
if (run_time->noaction) {
program = PROG_SKILL;
/* harmless */
sig_or_pri = 0;
}
if (program == PROG_SNICE)
sig_or_pri = prino;
else if (sig_or_pri < 0)
sig_or_pri = SIGTERM;
}
/* main body */
int main(int argc, char ** argv)
{
#ifdef HAVE_PROGRAM_INVOCATION_NAME
program_invocation_name = program_invocation_short_name;
#endif
struct run_time_conf_t run_time;
memset(&run_time, 0, sizeof(struct run_time_conf_t));
my_pid = getpid();
if (strcmp(program_invocation_short_name, "kill") == 0 ||
strcmp(program_invocation_short_name, "lt-kill") == 0)
program = PROG_KILL;
else if (strcmp(program_invocation_short_name, "skill") == 0 ||
strcmp(program_invocation_short_name, "lt-skill") == 0)
program = PROG_SKILL;
else if (strcmp(program_invocation_short_name, "snice") == 0 ||
strcmp(program_invocation_short_name, "lt-snice") == 0)
program = PROG_SNICE;
switch (program) {
case PROG_SNICE:
case PROG_SKILL:
setpriority(PRIO_PROCESS, my_pid, -20);
skillsnice_parse(argc, argv, &run_time);
if (run_time.debugging)
show_lists();
iterate(&run_time);
break;
case PROG_KILL:
kill_main(argc, argv);
break;
default:
fprintf(stderr, _("skill: \"%s\" is not supported\n"),
program_invocation_short_name);
fprintf(stderr, USAGE_MAN_TAIL("skill(1)"));
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}