zdtm: Add pty02 test

The test is tricky -- it opens master in task 1
and dup it in task 2, then close in task 1 and
do C/R.

Thus we need to setup SID of master terminal
somehow in children, which usually fails in
currnt tty restore implementation.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm/live/static/Makefile

@@ -53,6 +53,7 @@ TST_NOFILE	=				\
 		session00			\
 		pty00				\
 		pty01				\
+		pty02				\
 		tty00				\
 		mountpoints			\
 		netns				\

test/zdtm/live/static/pty02.c

+#define _XOPEN_SOURCE
+#include <stdlib.h>
+#include "zdtmtst.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <termios.h>
+#include <signal.h>
+
+const char *test_doc	= "Check forked master ptmx";
+const char *test_author	= "Cyrill Gorcunov <gorcunov@openvz.org>";
+
+static const char teststr[] = "ping\n";
+
+#define exit_shot(pid, code)	\
+	do { kill(pid, SIGKILL); exit(code); } while (0)
+
+#define exit_shot_parent(code)	\
+	exit_shot(getppid(), 1)
+
+int main(int argc, char *argv[])
+{
+	char buf[sizeof(teststr)];
+	int master, slave, ret;
+	char *slavename;
+	task_waiter_t t;
+	pid_t pid;
+
+	test_init(argc, argv);
+
+	master = open("/dev/ptmx", O_RDWR);
+	if (master == -1) {
+		err("open(%s) failed", "/dev/ptmx");
+		return 1;
+	}
+
+	grantpt(master);
+	unlockpt(master);
+
+	slavename = ptsname(master);
+	slave = open(slavename, O_RDWR);
+	if (slave == -1) {
+		err("open(%s) failed", slavename);
+		return 1;
+	}
+
+	task_waiter_init(&t);
+
+	pid = test_fork();
+	if (pid == 0) {
+		int new_master, ret;
+
+		new_master = dup(master);
+		if (new_master < 0) {
+			err("can't dup master\n");
+			exit_shot_parent(1);
+		}
+
+		task_waiter_complete_current(&t);
+
+		ret = write(new_master, teststr, sizeof(teststr) - 1);
+		if (ret != sizeof(teststr) - 1) {
+			err("write(new_master) failed");
+			exit_shot_parent(1);
+		}
+
+		task_waiter_wait4(&t, 1);
+
+		close(new_master);
+		exit(0);
+	} else if (pid < 0) {
+		err("test_fork failed: %m\n");
+		exit(1);
+	}
+
+	task_waiter_wait4(&t, pid);
+	close(master);
+
+	test_daemon();
+	test_waitsig();
+
+	task_waiter_complete(&t, 1);
+
+	ret = read(slave, buf, sizeof(teststr) - 1);
+	if (ret != sizeof(teststr) - 1) {
+		err("read(slave) failed");
+		return 1;
+	}
+
+	if (strncmp(teststr, buf, sizeof(teststr) - 1)) {
+		fail("data mismatch");
+		return 1;
+	}
+
+	close(slave);
+
+	pass();
+
+	return 0;
+}