openvt,getty,vfork_daemon_rexec,mount: tighten up fd cleanup code

(will close all fd's > 2 on daemonization now)
getty: fix "getty -" support, and also do not try to chown/chmod "-"
telnetd: fix "lost ctty" bug
Yet another attempt on saner function names:
bb_sanitize_server_stdio(0/1) -> bb_sanitize_stdio() + bb_daemonize();

5 files changed, 16 insertions, 9 deletions

diff --git a/networking/fakeidentd.c b/networking/fakeidentd.c
index 8c07082fc..6f766a827 100644
--- a/networking/fakeidentd.c
+++ b/networking/fakeidentd.c
@@ -1,3 +1,5 @@
+/* NB: this file is to be removed soon. See isrv_identd.c */
+
 /* vi: set sw=4 ts=4: */
 /*
  * A fake identd server
diff --git a/networking/inetd.c b/networking/inetd.c
index 370dcbbe0..218f85e53 100644
--- a/networking/inetd.c
+++ b/networking/inetd.c
@@ -1292,9 +1292,9 @@ inetd_main(int argc, char *argv[])
 		/* reexec for vfork() do continue parent */
 		vfork_daemon_rexec(0, 0, argc, argv, "-f");
 	}
-	bb_sanitize_server_stdio(0);
+	bb_sanitize_stdio();
 #else
-	bb_sanitize_server_stdio(!(opt & 2));
+	bb_sanitize_stdio_maybe_daemonize(!(opt & 2));
 #endif
 	openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
 	logmode = LOGMODE_SYSLOG;
diff --git a/networking/isrv_identd.c b/networking/isrv_identd.c
index e757d7c29..2d4399cea 100644
--- a/networking/isrv_identd.c
+++ b/networking/isrv_identd.c
@@ -111,7 +111,7 @@ int fakeidentd_main(int argc, char **argv)
 		bogouser = argv[optind];
 
 	/* Daemonize if no -f and no -i and no -w */
-	bb_sanitize_server_stdio(!(opt & OPT_fiw));
+	bb_sanitize_stdio_maybe_daemonize(!(opt & OPT_fiw));
 	/* Where to log in inetd modes? "Classic" inetd
 	 * probably has its stderr /dev/null'ed (we need log to syslog?),
 	 * but daemontools-like utilities usually expect that children
diff --git a/networking/telnetd.c b/networking/telnetd.c
index 51bd0c012..25cba3eb0 100644
--- a/networking/telnetd.c
+++ b/networking/telnetd.c
@@ -283,15 +283,19 @@ make_new_session(
 
 	/* child */
 
+	/* make new process group */
+	setsid();
+	tcsetpgrp(0, getpid());
+	/* ^^^ strace says: "ioctl(0, TIOCSPGRP, [pid]) = -1 ENOTTY" -- ??! */
+
 	/* open the child's side of the tty. */
-	fd = xopen(tty_name, O_RDWR /*| O_NOCTTY*/);
+	/* NB: setsid() disconnects from any previous ctty's. Therefore
+	 * we must open child's side of the tty AFTER setsid! */
+	fd = xopen(tty_name, O_RDWR); /* becomes our ctty */
 	dup2(fd, 0);
 	dup2(fd, 1);
 	dup2(fd, 2);
 	while (fd > 2) close(fd--);
-	/* make new process group */
-	setsid();
-	tcsetpgrp(0, getpid());
 
 	/* The pseudo-terminal allocated to the client is configured to operate in
 	 * cooked mode, and with XTABS CRMOD enabled (see tty(4)). */
diff --git a/networking/zcip.c b/networking/zcip.c
index 27e281c93..5d57c4287 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -221,7 +221,8 @@ int zcip_main(int argc, char *argv[])
 	}
 	if (opts & 4) { // -r n.n.n.n
 		if (inet_aton(r_opt, &ip) == 0
-		|| (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR) {
+		 || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR
+		) {
 			bb_error_msg_and_die("invalid link address");
 		}
 	}
@@ -270,7 +271,7 @@ int zcip_main(int argc, char *argv[])
 	// daemonize now; don't delay system startup
 	if (!FOREGROUND) {
 		setsid();
-		xdaemon(0, 0);
+		bb_daemonize();
 		bb_info_msg("start, interface %s", intf);
 	}