nfs-utils: consolidate mydaemon() and release_parent() implementations

We currently have 2 cut-and-paste versions of this code. One for idmapd
and one for svcgssd.[1]

The two are basically equivalent but there are some small differences,
mostly related to how errors in that function are logged. svcgssd uses
printerr() with a priority of 1, which only prints errors if -v was
specified. That doesn't seem to be quite right. Daemonizing errors are
necessarily fatal and should be logged as such. The one for idmapd uses
err(), which always prints to stderr even though we have the xlog
facility set up. Since both have xlog configured at this point, log the
errors using xlog_err() instead.

The only other significant difference I see is that the idmapd version
will open "/" if it's unable to open "/dev/null". I believe that however
was a holdover from an earlier version of that function that did not
error out when we were unable to open a file descriptor. Since the
function does that now, I don't believe we need that fallback anymore.

[1]: technically, we have a third in statd too, but it's different
     enough that I don't want to touch it here.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

1 files changed, 3 insertions, 79 deletions

diff --git a/utils/idmapd/idmapd.c b/utils/idmapd/idmapd.c
index b6c6231..c02849b 100644
--- a/utils/idmapd/idmapd.c
+++ b/utils/idmapd/idmapd.c
@@ -157,9 +157,6 @@ static int nfsdopenone(struct idmap_client *);
 static void nfsdreopen_one(struct idmap_client *);
 static void nfsdreopen(void);
 
-void    mydaemon(int, int);
-void    release_parent(void);
-
 static int verbose = 0;
 #define DEFAULT_IDMAP_CACHE_EXPIRY 600 /* seconds */
 static int cache_entry_expiration = 0;
@@ -167,6 +164,7 @@ static char pipefsdir[PATH_MAX];
 static char *nobodyuser, *nobodygroup;
 static uid_t nobodyuid;
 static gid_t nobodygid;
+static int pipefds[2] = { -1, -1 };
 
 /* Used by conffile.c in libnfs.a */
 char *conf_path;
@@ -305,7 +303,7 @@ main(int argc, char **argv)
 		errx(1, "Unable to create name to user id mappings.");
 
 	if (!fg)
-		mydaemon(0, 0);
+		mydaemon(0, 0, pipefds);
 
 	event_init();
 
@@ -382,7 +380,7 @@ main(int argc, char **argv)
 	if (nfsdret != 0 && fd == 0)
 		xlog_err("main: Neither NFS client nor NFSd found");
 
-	release_parent();
+	release_parent(pipefds);
 
 	if (event_dispatch() < 0)
 		xlog_err("main: event_dispatch returns errno %d (%s)",
@@ -929,77 +927,3 @@ getfield(char **bpp, char *fld, size_t fldsz)
 
 	return (0);
 }
-/*
- * mydaemon creates a pipe between the partent and child
- * process. The parent process will wait until the
- * child dies or writes a '1' on the pipe signaling
- * that it started successfully.
- */
-int pipefds[2] = { -1, -1};
-
-void
-mydaemon(int nochdir, int noclose)
-{
-	int pid, status, tempfd;
-
-	if (pipe(pipefds) < 0)
-		err(1, "mydaemon: pipe() failed: errno %d", errno);
-
-	if ((pid = fork ()) < 0)
-		err(1, "mydaemon: fork() failed: errno %d", errno);
-
-	if (pid != 0) {
-		/*
-		 * Parent. Wait for status from child.
-		 */
-		close(pipefds[1]);
-		if (read(pipefds[0], &status, 1) != 1)
-			exit(1);
-		exit (0);
-	}
-	/* Child.	*/
-	close(pipefds[0]);
-	setsid ();
-	if (nochdir == 0) {
-		if (chdir ("/") == -1)
-			err(1, "mydaemon: chdir() failed: errno %d", errno);
-	}
-
-	while (pipefds[1] <= 2) {
-		pipefds[1] = dup(pipefds[1]);
-		if (pipefds[1] < 0)
-			err(1, "mydaemon: dup() failed: errno %d", errno);
-	}
-
-	if (noclose == 0) {
-		tempfd = open("/dev/null", O_RDWR);
-		if (tempfd < 0)
-			tempfd = open("/", O_RDONLY);
-		if (tempfd >= 0) {
-			dup2(tempfd, 0);
-			dup2(tempfd, 1);
-			dup2(tempfd, 2);
-			close(tempfd);
-		} else {
-			err(1, "mydaemon: can't open /dev/null: errno %d",
-			       errno);
-			exit(1);
-		}
-	}
-
-	return;
-}
-void
-release_parent(void)
-{
-	int status;
-
-	if (pipefds[1] > 0) {
-		if (write(pipefds[1], &status, 1) != 1) {
-			err(1, "Writing to parent pipe failed: errno %d (%s)\n",
-				errno, strerror(errno));
-		}
-		close(pipefds[1]);
-		pipefds[1] = -1;
-	}
-}