Use pidfile(3) provided by libutil to manage the deamon's pid file.

By default, create a pid file at the standard location, /var/run/ftpd.pid,
in accord with the expected behavior of a stock system daemon.

MFC after:	5 days

2 files changed, 25 insertions, 30 deletions

diff --git a/libexec/ftpd/ftpd.8 b/libexec/ftpd/ftpd.8
index aed7d5d..7d62e6b 100644
--- a/libexec/ftpd/ftpd.8
+++ b/libexec/ftpd/ftpd.8
@@ -144,7 +144,9 @@ port.
 When
 .Fl D
 is specified, write the daemon's process ID to
-.Ar file .
+.Ar file
+instead of the default pid file,
+.Pa /var/run/ftpd.pid .
 .It Fl R
 With this option set,
 .Nm
@@ -519,7 +521,7 @@ executable need not be placed into the chrooted tree, nor need the
 .Pa ~/bin
 directory exist.
 .Sh FILES
-.Bl -tag -width ".Pa /var/log/xferlog" -compact
+.Bl -tag -width ".Pa /var/run/ftpd.pid" -compact
 .It Pa /etc/ftpusers
 List of unwelcome/restricted users.
 .It Pa /etc/ftpchroot
@@ -530,6 +532,8 @@ Virtual hosting configuration file.
 Welcome notice.
 .It Pa /etc/ftpmotd
 Welcome notice after login.
+.It Pa /var/run/ftpd.pid
+Default pid file for daemon mode.
 .It Pa /var/run/nologin
 Displayed and access refused.
 .It Pa /var/log/ftpd
diff --git a/libexec/ftpd/ftpd.c b/libexec/ftpd/ftpd.c
index 1334757..9590f78 100644
--- a/libexec/ftpd/ftpd.c
+++ b/libexec/ftpd/ftpd.c
@@ -187,7 +187,7 @@ static struct opie	opiedata;
 static char		opieprompt[OPIE_CHALLENGE_MAX+1];
 static int		pwok;
 
-char	*pid_file = NULL;
+char	*pid_file = NULL; /* means default location to pidfile(3) */
 
 /*
  * Limit number of pathnames that glob can return.
@@ -431,6 +431,16 @@ main(int argc, char *argv[], char **envp)
 		int *ctl_sock, fd, maxfd = -1, nfds, i;
 		fd_set defreadfds, readfds;
 		pid_t pid;
+		struct pidfh *pfh;
+
+		if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
+			if (errno == EEXIST) {
+				syslog(LOG_ERR, "%s already running, pid %d",
+				       getprogname(), (int)pid);
+				exit(1);
+			}
+			syslog(LOG_WARNING, "pidfile_open: %m");
+		}
 
 		/*
 		 * Detach from parent.
@@ -439,6 +449,10 @@ main(int argc, char *argv[], char **envp)
 			syslog(LOG_ERR, "failed to become a daemon");
 			exit(1);
 		}
+
+		if (pfh != NULL && pidfile_write(pfh) == -1)
+			syslog(LOG_WARNING, "pidfile_write: %m");
+
 		sa.sa_handler = reapchild;
 		(void)sigaction(SIGCHLD, &sa, NULL);
 
@@ -462,32 +476,6 @@ main(int argc, char *argv[], char **envp)
 		}
 
 		/*
-		 * Atomically write process ID
-		 */
-		if (pid_file)
-		{
-			int fd;
-			char buf[20];
-
-			fd = open(pid_file, O_CREAT | O_WRONLY | O_TRUNC
-				| O_NONBLOCK | O_EXLOCK, 0644);
-			if (fd < 0) {
-				if (errno == EAGAIN)
-					syslog(LOG_ERR,
-					    "%s: already locked", pid_file);
-				else
-					syslog(LOG_ERR, "%s: %m", pid_file);
-				exit(1);
-			}
-			snprintf(buf, sizeof(buf),
-				"%lu\n", (unsigned long) getpid());
-			if (write(fd, buf, strlen(buf)) < 0) {
-				syslog(LOG_ERR, "%s: write: %m", pid_file);
-				exit(1);
-			}
-			/* Leave the pid file open and locked */
-		}
-		/*
 		 * Loop forever accepting connection requests and forking off
 		 * children to handle them.
 		 */
@@ -517,8 +505,11 @@ main(int argc, char *argv[], char **envp)
 							close(fd);
 					}
 				}
-			if (pid == 0)
+			if (pid == 0) {
+				if (pfh != NULL)
+					pidfile_close(pfh);
 				break;
+			}
 		}
 	} else {
 		addrlen = sizeof(his_addr);