console: add some pty helpers

src/lxc/conf.c

@@ -73,6 +73,7 @@
 #include "cgroup.h"
 #include "conf.h"
 #include "confile_utils.h"
+#include "console.h"
 #include "error.h"
 #include "log.h"
 #include "lxclock.h"
@@ -3489,8 +3490,7 @@ void lxc_conf_free(struct lxc_conf *conf)
 		return;
 	if (current_config == conf)
 		current_config = NULL;
-	free(conf->console.log_path);
-	free(conf->console.path);
+	lxc_pty_conf_free(&conf->console);
 	free(conf->rootfs.mount);
 	free(conf->rootfs.bdev_type);
 	free(conf->rootfs.options);

src/lxc/console.c

@@ -861,3 +861,58 @@ close_fds:
 
 	return ret;
 }
+
+int lxc_make_controlling_pty(int fd)
+{
+	int ret;
+
+	setsid();
+
+	ret = ioctl(fd, TIOCSCTTY, (char *)NULL);
+	if (ret < 0)
+		return -1;
+
+	return 0;
+}
+
+int lxc_login_pty(int fd)
+{
+	int ret;
+
+	ret = lxc_make_controlling_pty(fd);
+	if (ret < 0)
+		return -1;
+
+	ret = lxc_console_set_stdfds(fd);
+	if (ret < 0)
+		return -1;
+
+	if (fd > STDERR_FILENO)
+		close(fd);
+
+	return 0;
+}
+
+void lxc_pty_info_init(struct lxc_pty_info *pty)
+{
+	pty->name[0] = '\0';
+	pty->master = -EBADF;
+	pty->slave = -EBADF;
+	pty->busy = -1;
+}
+
+void lxc_pty_init(struct lxc_console *pty)
+{
+	memset(pty, 0, sizeof(*pty));
+	pty->slave = -EBADF;
+	pty->master = -EBADF;
+	pty->peer = -EBADF;
+	pty->log_fd = -EBADF;
+	lxc_pty_info_init(&pty->peerpty);
+}
+
+void lxc_pty_conf_free(struct lxc_console *console)
+{
+	free(console->log_path);
+	free(console->path);
+}

src/lxc/console.h

@@ -230,4 +230,10 @@ extern void lxc_console_signal_fini(struct lxc_tty_state *ts);
 extern int lxc_console_cb_con(int fd, uint32_t events, void *data,
 			      struct lxc_epoll_descr *descr);
 
+extern int lxc_make_controlling_pty(int fd);
+extern int lxc_login_pty(int fd);
+extern void lxc_pty_conf_free(struct lxc_console *console);
+extern void lxc_pty_info_init(struct lxc_pty_info *pty);
+extern void lxc_pty_init(struct lxc_console *pty);
+
 #endif

src/lxc/start.c

@@ -665,6 +665,7 @@ on_error:
 
 int lxc_init(const char *name, struct lxc_handler *handler)
 {
+	int ret;
 	const char *loglevel;
 	struct lxc_conf *conf = handler->conf;