Refactored sys_fork() and sys_pid() into shared util library

This fixes a bug in 116ce19b, where we didn't clear the pid cache in
become_daemon() and thus the /var/run/smbd.pid didn't match the actual
pid of the parent process.

Currently S4 will clear the pid cache on fork but doesn't yet take
advantage of the pid cache by using sys_pid() instead of the direct
get_pid().

1 files changed, 29 insertions, 0 deletions

diff --git a/lib/util/system.c b/lib/util/system.c
index 9bd1800233..9bf5de1a83 100644
--- a/lib/util/system.c
+++ b/lib/util/system.c
@@ -88,3 +88,32 @@ _PUBLIC_ struct in_addr sys_inet_makeaddr(int net, int host)
 	return in2;
 }
 
+/**************************************************************************
+ Wrapper for fork. Ensures we clear our pid cache.
+****************************************************************************/
+
+static pid_t mypid = (pid_t)-1;
+
+_PUBLIC_ pid_t sys_fork(void)
+{
+	pid_t forkret = fork();
+
+	if (forkret == (pid_t)0) {
+		/* Child - reset mypid so sys_getpid does a system call. */
+		mypid = (pid_t) -1;
+	}
+
+	return forkret;
+}
+
+/**************************************************************************
+ Wrapper for getpid. Ensures we only do a system call *once*.
+****************************************************************************/
+
+_PUBLIC_ pid_t sys_getpid(void)
+{
+	if (mypid == (pid_t)-1)
+		mypid = getpid();
+
+	return mypid;
+}