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Using fifos for locking can be error prone.

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flocks are safer, as we only use tmpfs for our lock files.

I don't know how this works for inactive just yet though ...
This commit is contained in:
Roy Marples 2009-04-17 22:55:11 +00:00
parent 7138c1532c
commit ee54bb9372
3 changed files with 97 additions and 164 deletions
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2
src/includes/rc-misc.h
View File

@ -150,6 +150,8 @@ bool rc_conf_yesno(const char *var);
void env_filter(void);
void env_config(void);
int signal_setup(int sig, void (*handler)(int));
int svc_lock(const char *);
int svc_unlock(const char *, int);
pid_t exec_service(const char *, const char *);
#define service_start(service) exec_service(service, "start");

52
src/rc/rc-misc.c
View File

@ -29,6 +29,7 @@
* SUCH DAMAGE.
*/
#include <sys/file.h>
#include <sys/types.h>
#include <sys/utsname.h>
@ -38,6 +39,7 @@
#endif
#include <ctype.h>
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
@ -270,30 +272,56 @@ signal_setup(int sig, void (*handler)(int))
return sigaction(sig, &sa, NULL);
}
int
svc_lock(const char *applet)
{
char file[PATH_MAX];
int fd;
snprintf(file, sizeof(file), RC_SVCDIR "/exclusive/%s", applet);
fd = open(file, O_WRONLY | O_CREAT | O_NONBLOCK, 0664);
if (fd == -1)
return -1;
if (flock(fd, LOCK_EX | LOCK_NB) == -1) {
close(fd);
return -1;
}
return fd;
}
int
svc_unlock(const char *applet, int fd)
{
char file[PATH_MAX];
snprintf(file, sizeof(file), RC_SVCDIR "/exclusive/%s", applet);
close(fd);
unlink(file);
return -1;
}
pid_t
exec_service(const char *service, const char *arg)
{
char *file;
char fifo[PATH_MAX];
char *file, sfd[32];
int fd;
pid_t pid = -1;
sigset_t full;
sigset_t old;
struct sigaction sa;
fd = svc_lock(basename_c(service));
if (fd == -1)
return -1;
file = rc_service_resolve(service);
if (!exists(file)) {
rc_service_mark(service, RC_SERVICE_STOPPED);
svc_unlock(basename_c(service), fd);
free(file);
return 0;
}
/* We create a fifo so that other services can wait until we complete */
snprintf(fifo, sizeof(fifo), RC_SVCDIR "/exclusive/%s",
basename_c(service));
if (mkfifo(fifo, 0600) != 0 && errno != EEXIST) {
free(file);
return -1;
}
snprintf(sfd, sizeof(sfd), "%d", fd);
/* We need to block signals until we have forked */
memset(&sa, 0, sizeof (sa));
@ -316,10 +344,10 @@ exec_service(const char *service, const char *arg)
sigprocmask(SIG_SETMASK, &old, NULL);
/* Safe to run now */
execl(file, file, arg, (char *) NULL);
execl(file, file, "--lockfd", sfd, arg, (char *) NULL);
fprintf(stderr, "unable to exec `%s': %s\n",
file, strerror(errno));
unlink(fifo);
svc_unlock(basename_c(service), fd);
_exit(EXIT_FAILURE);
}

201
src/rc/runscript.c
View File

@ -86,8 +86,7 @@ static RC_STRINGLIST *use_services = NULL;
static RC_STRINGLIST *services = NULL;
static RC_STRINGLIST *tmplist = NULL;
static char *service = NULL;
static char exclusive[PATH_MAX] = { '\0' };
static char mtime_test[PATH_MAX] = { '\0' };
static int exclusive_fd = -1;
static RC_DEPTREE *deptree = NULL;
static char *runlevel = NULL;
static bool sighup = false;
@ -195,58 +194,6 @@ handle_signal(int sig)
errno = serrno;
}
static time_t
get_mtime(const char *pathname, bool follow_link)
{
struct stat buf;
int retval;
if (!pathname)
return 0;
retval = follow_link ? stat(pathname, &buf) : lstat(pathname, &buf);
if (!retval)
return buf.st_mtime;
errno = 0;
return 0;
}
static const char *const tests[] = {
"starting", "started", "stopping", "inactive", "wasinactive", NULL
};
static bool
in_control()
{
char file[PATH_MAX];
time_t m;
time_t mtime;
int i = 0;
if (sighup)
return false;
if (!*mtime_test || !exists(mtime_test))
return false;
if (rc_service_state(applet) & RC_SERVICE_STOPPED)
return false;
if (!(mtime = get_mtime(mtime_test, false)))
return false;
while (tests[i]) {
snprintf(file, sizeof(file), RC_SVCDIR "/%s/%s",
tests[i], applet);
if (exists(file)) {
m = get_mtime(file, false);
if (mtime < m && m != 0)
return false;
}
i++;
}
return true;
}
static void
unhotplug()
{
@ -294,7 +241,7 @@ restore_state(void)
{
RC_SERVICE state;
if (rc_in_plugin || !in_control())
if (rc_in_plugin || exclusive_fd == -1)
return;
state = rc_service_state(applet);
if (state & RC_SERVICE_STOPPING) {
@ -312,11 +259,7 @@ restore_state(void)
if (rc_runlevel_starting())
rc_service_mark(applet, RC_SERVICE_FAILED);
}
if (*exclusive) {
unlink(exclusive);
*exclusive = '\0';
}
exclusive_fd = svc_unlock(applet, exclusive_fd);
}
static void
@ -360,9 +303,6 @@ cleanup(void)
free(prefix);
free(runlevel);
#endif
if (*mtime_test && !rc_in_plugin)
unlink(mtime_test);
}
static int
@ -539,11 +479,11 @@ svc_exec(const char *arg1, const char *arg2)
static bool
svc_wait(const char *svc)
{
char fifo[PATH_MAX];
char file[PATH_MAX];
struct timespec ts;
int nloops = WAIT_MAX * (ONE_SECOND / WAIT_INTERVAL);
int sloops = (ONE_SECOND / WAIT_INTERVAL) * 5;
bool retval = false;
int fd;
bool forever = false;
RC_STRINGLIST *keywords;
@ -553,20 +493,28 @@ svc_wait(const char *svc)
forever = true;
rc_stringlist_free(keywords);
snprintf(fifo, sizeof(fifo), RC_SVCDIR "/exclusive/%s",
snprintf(file, sizeof(file), RC_SVCDIR "/exclusive/%s",
basename_c(svc));
ts.tv_sec = 0;
ts.tv_nsec = WAIT_INTERVAL;
while (nloops) {
if (!exists(fifo)) {
retval = true;
break;
fd = open(file, O_RDONLY | O_NONBLOCK);
if (fd != -1) {
if (flock(fd, LOCK_SH | LOCK_NB) == 0) {
close(fd);
return true;
}
close(fd);
}
if (errno == ENOENT)
return true;
if (errno != EWOULDBLOCK)
eerrorx("%s: open `%s': %s", applet, file, strerror(errno));
if (nanosleep(&ts, NULL) == -1) {
if (errno != EINTR)
break;
return false;
}
if (!forever) {
@ -579,9 +527,7 @@ svc_wait(const char *svc)
}
}
if (!exists(fifo))
retval = true;
return retval;
return false;
}
static RC_SERVICE
@ -617,45 +563,6 @@ svc_status(void)
return state;
}
static void
make_exclusive(void)
{
/* We create a fifo so that other services can wait until we complete */
if (!*exclusive)
snprintf(exclusive, sizeof(exclusive),
RC_SVCDIR "/exclusive/%s", applet);
if (mkfifo(exclusive, 0600) != 0 && errno != EEXIST &&
(errno != EACCES || geteuid () == 0))
eerrorx ("%s: unable to create fifo `%s': %s",
applet, exclusive, strerror(errno));
snprintf(mtime_test, sizeof(mtime_test),
RC_SVCDIR "/exclusive/%s.%d", applet, getpid());
if (exists(mtime_test) && unlink(mtime_test) != 0) {
eerror("%s: unlink `%s': %s",
applet, mtime_test, strerror(errno));
*mtime_test = '\0';
return;
}
if (symlink(service, mtime_test) != 0) {
eerror("%s: symlink `%s' to `%s': %s",
applet, service, mtime_test, strerror(errno));
*mtime_test = '\0';
}
}
static void
unlink_mtime_test(void)
{
if (unlink(mtime_test) != 0)
eerror("%s: unlink `%s': %s",
applet, mtime_test, strerror(errno));
*mtime_test = '\0';
}
static void
get_started_services(void)
{
@ -722,24 +629,25 @@ svc_start(bool deps)
" next runlevel", applet);
}
if (exclusive_fd == -1)
exclusive_fd = svc_lock(applet);
if (exclusive_fd == -1) {
if (errno == EACCES)
eerrorx("%s: superuser access required", applet);
if (state & RC_SERVICE_STOPPING)
ewarnx("WARNING: %s is stopping", applet);
else
ewarnx("WARNING: %s is already starting", applet);
}
if (state & RC_SERVICE_STARTED) {
ewarn("WARNING: %s has already been started", applet);
return;
} else if (state & RC_SERVICE_STARTING)
ewarnx("WARNING: %s is already starting", applet);
else if (state & RC_SERVICE_STOPPING)
ewarnx("WARNING: %s is stopping", applet);
else if (state & RC_SERVICE_INACTIVE && ! background)
} else if (state & RC_SERVICE_INACTIVE && ! background)
ewarnx("WARNING: %s has already started, but is inactive",
applet);
if (!rc_service_mark(service, RC_SERVICE_STARTING)) {
if (errno == EACCES)
eerrorx("%s: superuser access required", applet);
eerrorx("ERROR: %s has been started by something else", applet);
}
make_exclusive();
rc_service_mark(service, RC_SERVICE_STARTING);
hook_out = RC_HOOK_SERVICE_START_OUT;
rc_plugin_run(RC_HOOK_SERVICE_START_IN, applet);
@ -838,7 +746,6 @@ svc_start(bool deps)
/* Set the state now, then unlink our exclusive so that
our scheduled list is preserved */
rc_service_mark(service, RC_SERVICE_STOPPED);
unlink_mtime_test();
rc_stringlist_free(use_services);
use_services = NULL;
@ -885,23 +792,18 @@ svc_start(bool deps)
if (ibsave)
unsetenv("IN_BACKGROUND");
if (in_control()) {
if (!started)
eerrorx("ERROR: %s failed to start", applet);
} else {
else {
if (rc_service_state(service) & RC_SERVICE_INACTIVE)
ewarnx("WARNING: %s has started, but is inactive",
applet);
else
ewarnx("WARNING: %s not under our control, aborting",
applet);
}
rc_service_mark(service, RC_SERVICE_STARTED);
unlink_mtime_test();
exclusive_fd = svc_unlock(applet, exclusive_fd);
hook_out = RC_HOOK_SERVICE_START_OUT;
rc_plugin_run(RC_HOOK_SERVICE_START_DONE, applet);
unlink(exclusive);
/* Now start any scheduled services */
services = rc_services_scheduled(service);
@ -948,28 +850,29 @@ svc_stop(bool deps)
!(state & RC_SERVICE_INACTIVE))
exit (EXIT_FAILURE);
if (exclusive_fd == -1)
exclusive_fd = svc_lock(applet);
if (exclusive_fd == -1) {
if (errno == EACCES)
eerrorx("%s: superuser access required", applet);
if (state & RC_SERVICE_STOPPING)
ewarnx("WARNING: %s is already stopping", applet);
eerrorx("ERROR: %d %s has been stopped by something else", exclusive_fd, applet);
}
if (state & RC_SERVICE_STOPPED) {
ewarn("WARNING: %s is already stopped", applet);
return;
} else if (state & RC_SERVICE_STOPPING)
ewarnx("WARNING: %s is already stopping", applet);
if (!rc_service_mark(service, RC_SERVICE_STOPPING)) {
if (errno == EACCES)
eerrorx("%s: superuser access required", applet);
eerrorx("ERROR: %s has been stopped by something else", applet);
}
make_exclusive();
rc_service_mark(service, RC_SERVICE_STOPPING);
hook_out = RC_HOOK_SERVICE_STOP_OUT;
rc_plugin_run(RC_HOOK_SERVICE_STOP_IN, applet);
if (!rc_runlevel_stopping()) {
if (rc_service_in_runlevel(service, RC_LEVEL_SYSINIT))
ewarn ("WARNING: you are stopping a sysinit service");
ewarn("WARNING: you are stopping a sysinit service");
else if (rc_service_in_runlevel(service, RC_LEVEL_BOOT))
ewarn ("WARNING: you are stopping a boot service");
ewarn("WARNING: you are stopping a boot service");
}
if (deps && !(state & RC_SERVICE_WASINACTIVE)) {
@ -1062,9 +965,6 @@ svc_stop(bool deps)
if (ibsave)
unsetenv("IN_BACKGROUND");
if (!in_control())
ewarnx("WARNING: %s not under our control, aborting", applet);
if (!stopped)
eerrorx("ERROR: %s failed to stop", applet);
@ -1073,10 +973,8 @@ svc_stop(bool deps)
else
rc_service_mark(service, RC_SERVICE_STOPPED);
unlink_mtime_test();
hook_out = RC_HOOK_SERVICE_STOP_OUT;
rc_plugin_run(RC_HOOK_SERVICE_STOP_DONE, applet);
unlink(exclusive);
hook_out = 0;
rc_plugin_run(RC_HOOK_SERVICE_STOP_OUT, applet);
}
@ -1148,18 +1046,20 @@ service_plugable(void)
}
#include "_usage.h"
#define getoptstring "dDsv" getoptstring_COMMON
#define getoptstring "dDsvl:" getoptstring_COMMON
#define extraopts "stop | start | restart | describe | zap"
static const struct option longopts[] = {
{ "debug", 0, NULL, 'd'},
{ "ifstarted", 0, NULL, 's'},
{ "nodeps", 0, NULL, 'D'},
{ "lockfd", 1, NULL, 'l'},
longopts_COMMON
};
static const char *const longopts_help[] = {
"set xtrace when running the script",
"only run commands when started",
"ignore dependencies",
"fd of the exclusive lock from rc",
longopts_help_COMMON
};
#include "_usage.c"
@ -1291,6 +1191,9 @@ runscript(int argc, char **argv)
case 'd':
setenv("RC_DEBUG", "YES", 1);
break;
case 'l':
exclusive_fd = atoi(optarg);
break;
case 's':
if (!(rc_service_state(service) & RC_SERVICE_STARTED))
exit(EXIT_FAILURE);