Viewing file:  start-stop-daemon.c (8.78 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* A rewrite of the original Debian's start-stop-daemon Perl script
* in C (faster - it is executed many times during system startup).
*
* Written by Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>,
* public domain.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <signal.h>
#include <errno.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <getopt.h>
#include <pwd.h>
#define VERSION "version 0.3, 1996-06-05"
static int testmode = 0;
static int quietmode = 0;
static int exitnodo = 1;
static int start = 0;
static int stop = 0;
static int signal_nr = 15;
static int user_id = -1;
static const char *userspec = NULL;
static const char *cmdname = NULL;
static char *execname = NULL;
static char *startas = NULL;
static const char *pidfile = NULL;
static const char *progname = "";
static struct stat exec_stat;
struct pid_list {
struct pid_list *next;
int pid;
};
static struct pid_list *found = NULL;
static struct pid_list *killed = NULL;
static void *xmalloc(int size);
static void push(struct pid_list **list, int pid);
static void do_help(void);
static void parse_options(int argc, char * const *argv);
static int pid_is_exec(int pid, const struct stat *esb);
static int pid_is_user(int pid, int uid);
static int pid_is_cmd(int pid, const char *name);
static void check(int pid);
static void do_pidfile(const char *name);
static void do_procfs(void);
static void do_stop(void);
#ifdef __GNUC__
static void fatal(const char *format, ...)
__attribute__((noreturn, format(printf, 1, 2)));
static void badusage(const char *msg)
__attribute__((noreturn));
#else
static void fatal(const char *format, ...);
static void badusage(const char *msg);
#endif
static void
fatal(const char *format, ...)
{
va_list arglist;
fprintf(stderr, "%s: ", progname);
va_start(arglist, format);
vfprintf(stderr, format, arglist);
va_end(arglist);
putc('\n', stderr);
exit(2);
}
static void *
xmalloc(int size)
{
void *ptr;
ptr = malloc(size);
if (ptr)
return ptr;
fatal("malloc(%d) failed", size);
}
static void
push(struct pid_list **list, int pid)
{
struct pid_list *p;
p = xmalloc(sizeof(*p));
p->next = *list;
p->pid = pid;
*list = p;
}
static void
do_help(void)
{
printf("\
start-stop-daemon for Debian Linux - small and fast C version written by\n\
Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>, public domain.\n"
VERSION "\n\
\n\
Usage:
start-stop-daemon -S|--start options ... -- arguments ...\n\
start-stop-daemon -K|--stop options ...\n\
start-stop-daemon -H|--help\n\
start-stop-daemon -V|--version\n\
\n\
Options (at least one of --exec|--pidfile|--user is required):
-x|--exec <executable> program to start/check if it is running\n\
-p|--pidfile <pid-file> pid file to check\n\
-u|--user <username>|<uid> stop this user's processes\n\
-n|--name <process-name> stop processes with this name\n\
-s|--signal <signal> signal to send (default 15)\n\
-a|--startas <pathname> program to start (default <executable>)\n\
-t|--test test mode, don't do anything\n\
-o|--oknodo exit status 0 (not 1) if nothing done\n\
-q|--quiet | -v, --verbose\n\
\n\
Exit status: 0 = done 1 = nothing done (=> 0 if --oknodo) 2 = trouble\n");
}
static void
badusage(const char *msg)
{
if (msg && *msg)
fprintf(stderr, "%s: %s\n", progname, msg);
fprintf(stderr, "Try `%s --help' for more information.\n", progname);
exit(2);
}
static void
parse_options(int argc, char * const *argv)
{
static struct option longopts[] = {
{ "help", 0, NULL, 'H'},
{ "stop", 0, NULL, 'K'},
{ "start", 0, NULL, 'S'},
{ "version", 0, NULL, 'V'},
{ "startas", 1, NULL, 'a'},
{ "name", 1, NULL, 'n'},
{ "oknodo", 0, NULL, 'o'},
{ "pidfile", 1, NULL, 'p'},
{ "quiet", 0, NULL, 'q'},
{ "signal", 1, NULL, 's'},
{ "test", 0, NULL, 't'},
{ "user", 1, NULL, 'u'},
{ "verbose", 0, NULL, 'v'},
{ "exec", 1, NULL, 'x'},
{ NULL, 0, NULL, 0}
};
int c;
for (;;) {
c = getopt_long(argc, argv, "HKSVa:n:op:qs:tu:vx:",
longopts, (int *) 0);
if (c == -1)
break;
switch (c) {
case 'H': /* --help */
do_help();
exit(0);
case 'K': /* --stop */
stop = 1;
break;
case 'S': /* --start */
start = 1;
break;
case 'V': /* --version */
printf("start-stop-daemon " VERSION "\n");
exit(0);
case 'a': /* --startas <pathname> */
startas = optarg;
break;
case 'n': /* --name <process-name> */
cmdname = optarg;
break;
case 'o': /* --oknodo */
exitnodo = 0;
break;
case 'p': /* --pidfile <pid-file> */
pidfile = optarg;
break;
case 'q': /* --quiet */
quietmode = 1;
break;
case 's': /* --signal <signal> */
if (sscanf(optarg, "%d", &signal_nr) != 1)
badusage("--signal takes a numeric argument");
break;
case 't': /* --test */
testmode = 1;
break;
case 'u': /* --user <username>|<uid> */
userspec = optarg;
break;
case 'v': /* --verbose */
quietmode = -1;
break;
case 'x': /* --exec <executable> */
execname = optarg;
break;
default:
badusage(""); /* message printed by getopt */
}
}
if (start == stop)
badusage("need one of --start or --stop");
if (!execname && !pidfile && !userspec)
badusage("need at least one of --exec, --pidfile or --user");
if (!startas)
startas = execname;
if (start && !startas)
badusage("--start needs --exec or --startas");
}
static int
pid_is_exec(int pid, const struct stat *esb)
{
struct stat sb;
char buf[32];
sprintf(buf, "/proc/%d/exe", pid);
if (stat(buf, &sb) != 0)
return 0;
return (sb.st_dev == esb->st_dev && sb.st_ino == esb->st_ino);
}
static int
pid_is_user(int pid, int uid)
{
struct stat sb;
char buf[32];
sprintf(buf, "/proc/%d", pid);
if (stat(buf, &sb) != 0)
return 0;
return (sb.st_uid == uid);
}
static int
pid_is_cmd(int pid, const char *name)
{
char buf[32];
FILE *f;
int c;
sprintf(buf, "/proc/%d/stat", pid);
f = fopen(buf, "r");
if (!f)
return 0;
while ((c = getc(f)) != EOF && c != '(')
;
if (c != '(') {
fclose(f);
return 0;
}
/* this hopefully handles command names containing ')' */
while ((c = getc(f)) != EOF && c == *name)
name++;
fclose(f);
return (c == ')' && *name == '\0');
}
static void
check(int pid)
{
if (execname && !pid_is_exec(pid, &exec_stat))
return;
if (userspec && !pid_is_user(pid, user_id))
return;
if (cmdname && !pid_is_cmd(pid, cmdname))
return;
push(&found, pid);
}
static void
do_pidfile(const char *name)
{
FILE *f;
int pid;
f = fopen(name, "r");
if (f) {
if (fscanf(f, "%d", &pid) == 1)
check(pid);
fclose(f);
}
}
static void
do_procfs(void)
{
DIR *procdir;
struct dirent *entry;
int foundany, pid;
procdir = opendir("/proc");
if (!procdir)
fatal("opendir /proc: %s", strerror(errno));
foundany = 0;
while ((entry = readdir(procdir)) != NULL) {
if (sscanf(entry->d_name, "%d", &pid) != 1)
continue;
foundany++;
check(pid);
}
closedir(procdir);
if (!foundany)
fatal("nothing in /proc - not mounted?");
}
static void
do_stop(void)
{
char what[1024];
struct pid_list *p;
if (cmdname)
strcpy(what, cmdname);
else if (execname)
strcpy(what, execname);
else if (pidfile)
sprintf(what, "process in pidfile `%s'", pidfile);
else if (userspec)
sprintf(what, "process(es) owned by `%s'", userspec);
else
fatal("internal error, please report");
if (!found) {
if (quietmode <= 0)
printf("no %s found; none killed.\n", what);
exit(exitnodo);
}
for (p = found; p; p = p->next) {
if (testmode)
printf("would send signal %d to %d.\n",
signal_nr, p->pid);
else if (kill(p->pid, signal_nr) == 0)
push(&killed, p->pid);
else
printf("%s: warning: failed to kill %d: %s\n",
progname, p->pid, strerror(errno));
}
if (quietmode < 0 && killed) {
printf("stopped %s (pid", what);
for (p = killed; p; p = p->next)
printf(" %d", p->pid);
printf(").\n");
}
}
int
main(int argc, char **argv)
{
progname = argv[0];
parse_options(argc, argv);
argc -= optind;
argv += optind;
if (execname && stat(execname, &exec_stat))
fatal("stat %s: %s", execname, strerror(errno));
if (userspec && sscanf(userspec, "%d", &user_id) != 1) {
struct passwd *pw;
pw = getpwnam(userspec);
if (!pw)
fatal("user `%s' not found\n", userspec);
user_id = pw->pw_uid;
}
if (pidfile)
do_pidfile(pidfile);
else
do_procfs();
if (stop) {
do_stop();
exit(0);
}
if (found) {
if (quietmode <= 0)
printf("%s already running.\n", execname);
exit(exitnodo);
}
if (testmode) {
printf("would start %s ", startas);
while (argc-- > 0)
printf("%s ", *argv++);
printf(".\n");
exit(0);
}
if (quietmode < 0)
printf("starting %s ...\n", startas);
*--argv = startas;
execv(startas, argv);
fatal("unable to start %s: %s", startas, strerror(errno));
}
|