The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=203df05b692b5e2b92c990d8971f5797e3a7a139
commit 203df05b692b5e2b92c990d8971f5797e3a7a139 Author: Ihor Antonov <[email protected]> AuthorDate: 2023-03-02 03:00:42 +0000 Commit: Kyle Evans <[email protected]> CommitDate: 2023-03-02 03:00:42 +0000 daemon: add supervision_enabled var explicitly name a bunch of boolean checks that enable supervison mode and improve comments Reviewed by: kevans Pull Request: https://github.com/freebsd/freebsd-src/pull/669 --- usr.sbin/daemon/daemon.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/usr.sbin/daemon/daemon.c b/usr.sbin/daemon/daemon.c index 0925d16a27a0..f15a3f567a8c 100644 --- a/usr.sbin/daemon/daemon.c +++ b/usr.sbin/daemon/daemon.c @@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$"); #include <pwd.h> #include <signal.h> #include <stdio.h> +#include <stdbool.h> #include <stdlib.h> #include <unistd.h> #include <string.h> @@ -141,6 +142,7 @@ usage(int exitcode) int main(int argc, char *argv[]) { + bool supervision_enabled = false; char *p = NULL; const char *pidfile = NULL; const char *logtag = "daemon"; @@ -275,18 +277,31 @@ main(int argc, char *argv[]) } /* Write out parent pidfile if needed. */ pidfile_write(ppfh); + /* - * If the pidfile or restart option is specified the daemon - * executes the command in a forked process and wait on child - * exit to remove the pidfile or restart the command. Normally - * we don't want the monitoring daemon to be terminated - * leaving the running process and the stale pidfile, so we - * catch SIGTERM and forward it to the children expecting to - * get SIGCHLD eventually. We also must fork() to obtain a - * readable pipe with the child for writing to a log file - * and syslog. + * Supervision mode is enabled if one of the following options are used: + * --child-pidfile -p + * --supervisor-pidfile -P + * --restart -r / --restart-delay -R + * --syslog -S + * --syslog-facility -l + * --syslog-priority -s + * --syslog-tag -T + * + * In supervision mode daemon executes the command in a forked process + * and observes the child by waiting for SIGCHILD. In supervision mode + * daemon must never exit before the child, this is necessary to prevent + * orphaning the child and leaving a stale pid file. + * To achieve this daemon catches SIGTERM and + * forwards it to the child, expecting to get SIGCHLD eventually. */ - if (pidfile || ppidfile || restart || outfd != -1 || dosyslog) { + supervision_enabled = pidfile != NULL || + ppidfile != NULL || + restart != 0 || + outfd != -1 || + dosyslog != 0; + + if (supervision_enabled) { struct sigaction act_term = { 0 }; struct sigaction act_chld = { 0 }; struct sigaction act_hup = { 0 };
