syslogd: Refactor backgrounding/daemonization w/ code from FreeBSD
Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
This commit is contained in:
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a3f3ed1833
commit
f46850b000
112
src/syslogd.c
112
src/syslogd.c
@ -167,7 +167,6 @@ void domark(void *arg);
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void doflush(void *arg);
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void debug_switch();
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void die(int sig);
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void doexit(int sig);
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void init();
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static int strtobytes(char *arg);
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static int cfparse(FILE *fp, struct files *newf);
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@ -175,6 +174,9 @@ int decode(char *name, struct _code *codetab);
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static void logit(char *, ...);
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void sighup_handler(int);
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static int validate(struct sockaddr *sa, const char *hname);
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static int waitdaemon(int);
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static void timedout(int);
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static int addpeer(struct peer *pe0)
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{
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@ -248,7 +250,7 @@ int usage(int code)
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int main(int argc, char *argv[])
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{
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pid_t ppid = getpid();
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pid_t ppid = 1;
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char *ptr;
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int pflag = 0, bflag = 0;
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int ch;
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@ -376,30 +378,10 @@ int main(int argc, char *argv[])
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else
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kern_console_off();
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if (!Foreground) {
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chdir("/");
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signal(SIGTERM, doexit);
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if (fork()) {
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/*
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* Parent process
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*/
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sleep(300);
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/*
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* Not reached unless something major went wrong. 5
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* minutes should be a fair amount of time to wait.
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* Please note that this procedure is important since
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* the father must not exit before syslogd isn't
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* initialized or the klogd won't be able to flush its
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* logs. -Joey
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*/
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exit(1);
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}
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signal(SIGTERM, SIG_DFL);
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for (int i = 0; i < getdtablesize(); i++)
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(void)close(i);
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untty();
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if (!Foreground && !Debug) {
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ppid = waitdaemon(30);
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if (ppid < 0)
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err(1, "Failed daemonizing");
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} else if (Debug) {
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debugging_on = 1;
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setlinebuf(stdout);
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@ -434,18 +416,16 @@ int main(int argc, char *argv[])
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debugging_on = 0;
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}
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/*
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* Send a signal to the parent to it can terminate.
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*/
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if (getpid() != ppid)
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kill(ppid, SIGTERM);
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/*
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* Tell system we're up and running by creating /run/syslogd.pid
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*/
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if (pidfile(PidFile))
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logit("Failed creating %s: %s", PidFile, strerror(errno));
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/* Tell parent we're up and running */
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if (ppid != 1)
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kill(ppid, SIGALRM);
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/* Main loop begins here. */
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for (;;) {
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int rc;
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@ -2009,11 +1989,73 @@ void die(int signo)
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}
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/*
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* Signal handler to terminate the parent process.
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* fork off and become a daemon, but wait for the child to come online
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* before returning to the parent, or we get disk thrashing at boot etc.
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* Set a timer so we don't hang forever if it wedges.
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*/
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void doexit(int signo)
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static int waitdaemon(int maxwait)
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{
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exit(0);
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int fd;
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int status;
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pid_t pid, childpid;
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childpid = fork();
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switch (childpid) {
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case -1:
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return -1;
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case 0:
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break;
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default:
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signal(SIGALRM, timedout);
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alarm(maxwait);
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while ((pid = wait3(&status, 0, NULL)) != -1) {
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if (WIFEXITED(status))
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errx(1, "child pid %d exited with return code %d",
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pid, WEXITSTATUS(status));
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if (WIFSIGNALED(status))
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errx(1, "child pid %d exited on signal %d%s",
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pid, WTERMSIG(status),
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WCOREDUMP(status) ? " (core dumped)" :
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"");
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if (pid == childpid) /* it's gone... */
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break;
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}
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exit(0);
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}
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if (setsid() == -1)
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return -1;
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(void)chdir("/");
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fd = open(_PATH_DEVNULL, O_RDWR, 0);
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if (fd != -1) {
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(void)dup2(fd, STDIN_FILENO);
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(void)dup2(fd, STDOUT_FILENO);
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(void)dup2(fd, STDERR_FILENO);
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if (fd > STDERR_FILENO)
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(void)close(fd);
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}
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return getppid();
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}
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/*
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* We get a SIGALRM from the child when it's running and finished doing it's
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* fsync()'s or O_SYNC writes for all the boot messages.
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*
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* We also get a signal from the kernel if the timer expires, so check to
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* see what happened.
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*/
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static void timedout(int signo)
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{
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int left;
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left = alarm(0);
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signal(SIGALRM, SIG_DFL);
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if (left == 0)
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errx(1, "timed out waiting for child");
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_exit(0);
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}
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/* Create fallback .conf with err+panic sent to console */
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