terminal: split out lxc_devpts_terminal() helper

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/terminal.c b/src/lxc/terminal.c
index 2f495bc6248aaecc57c8163f57dc9ec881b7d5b9..3125846404f4e25b4d5769d5eab75fd37fe4be32 100644 (file)
--- a/src/lxc/terminal.c
+++ b/src/lxc/terminal.c
@@ -909,34 +909,27 @@ err:
        return -ENODEV;
 }
 
-static int lxc_terminal_create_native(const char *name, const char *lxcpath,
-                                     struct lxc_conf *conf,
-                                     struct lxc_terminal *terminal)
+int lxc_devpts_terminal(int devpts_fd, struct lxc_conf *conf,
+                       int *ret_ptx, int *ret_pty, char buf[static PATH_MAX])
 {
-       __do_close int devpts_fd = -EBADF, fd_pty = -EBADF;
+       __do_close int fd_ptx = -EBADF, fd_opath_pty = -EBADF, fd_pty = -EBADF;
        int pty_nr = -1;
        int ret;
 
-       devpts_fd = lxc_cmd_get_devpts_fd(name, lxcpath);
-       if (devpts_fd < 0)
-               return log_error_errno(-1, errno, "Failed to receive devpts fd");
-
-       terminal->ptx = open_beneath(devpts_fd, "ptmx", O_RDWR | O_NOCTTY | O_CLOEXEC);
-       if (terminal->ptx < 0) {
+       fd_ptx = open_beneath(devpts_fd, "ptmx", O_RDWR | O_NOCTTY | O_CLOEXEC);
+       if (fd_ptx < 0) {
                if (errno == ENOSPC)
                        return systrace("Exceeded number of allocatable terminals");
 
                return syserror("Failed to open terminal multiplexer device");
        }
 
-       ret = unlockpt(terminal->ptx);
-       if (ret < 0) {
-               SYSWARN("Failed to unlock multiplexer device device");
-               goto err;
-       }
+       ret = unlockpt(fd_ptx);
+       if (ret < 0)
+               return syswarn_set(-ENODEV, "Failed to unlock multiplexer device device");
 
-       terminal->pty = ioctl(terminal->ptx, TIOCGPTPEER, O_RDWR | O_NOCTTY | O_CLOEXEC);
-       if (terminal->pty < 0) {
+       fd_pty = ioctl(fd_ptx, TIOCGPTPEER, O_RDWR | O_NOCTTY | O_CLOEXEC);
+       if (fd_pty < 0) {
                switch (errno) {
                case ENOTTY:
                        SYSTRACE("Pure fd-based terminal allocation not possible");
@@ -948,45 +941,54 @@ static int lxc_terminal_create_native(const char *name, const char *lxcpath,
                        SYSWARN("Failed to allocate new pty device");
                        break;
                }
-               goto err;
-       }
 
-       ret = ioctl(terminal->ptx, TIOCGPTN, &pty_nr);
-       if (ret) {
-               SYSWARN("Failed to retrieve name of terminal pty");
-               goto err;
+               return ret_errno(ENODEV);
        }
 
-       fd_pty = open_at(devpts_fd, fdstr(pty_nr), PROTECT_OPATH_FILE,
-                       PROTECT_LOOKUP_ABSOLUTE_XDEV, 0);
-       if (fd_pty < 0) {
-               SYSWARN("Failed to open terminal pty fd by path %d/%d", devpts_fd, pty_nr);
-               goto err;
-       }
+       ret = ioctl(fd_ptx, TIOCGPTN, &pty_nr);
+       if (ret)
+               return syswarn_set(-ENODEV, "Failed to retrieve name of terminal pty");
 
-       if (!same_file_lax(terminal->pty, fd_pty)) {
-               SYSWARN("Terminal file descriptor changed");
-               goto err;
-       }
+       fd_opath_pty = open_at(devpts_fd, fdstr(pty_nr), PROTECT_OPATH_FILE,
+                              PROTECT_LOOKUP_ABSOLUTE_XDEV, 0);
+       if (fd_opath_pty < 0)
+               return syswarn_set(-ENODEV, "Failed to open terminal pty fd by path %d/%d", devpts_fd, pty_nr);
 
-       ret = strnprintf(terminal->name, sizeof(terminal->name), "dev/pts/%d",
-                       pty_nr);
-       if (ret < 0) {
-               SYSWARN("Failed to create terminal pty name");
-               goto err;
-       }
+       if (!same_file_lax(fd_pty, fd_opath_pty))
+               return syswarn_set(-ENODEV, "Terminal file descriptor changed");
+
+       ret = strnprintf(buf, PATH_MAX, "dev/pts/%d", pty_nr);
+       if (ret < 0)
+               return syswarn_set(-ENODEV, "Failed to create terminal pty name");
+
+       *ret_ptx = move_fd(fd_ptx);
+       *ret_pty = move_fd(fd_pty);
+       return 0;
+}
+
+static int lxc_terminal_create_native(const char *name, const char *lxcpath,
+                                     struct lxc_conf *conf,
+                                     struct lxc_terminal *terminal)
+{
+       __do_close int devpts_fd = -EBADF;
+       int ret;
+
+       devpts_fd = lxc_cmd_get_devpts_fd(name, lxcpath);
+       if (devpts_fd < 0)
+               return log_error_errno(-1, errno, "Failed to receive devpts fd");
+
+       ret = lxc_devpts_terminal(devpts_fd, conf, &terminal->ptx,
+                                 &terminal->pty, terminal->name);
+       if (ret < 0)
+               return ret;
 
        ret = lxc_terminal_peer_default(terminal);
        if (ret < 0) {
-               SYSWARN("Failed to allocate proxy terminal");
-               goto err;
+               lxc_terminal_delete(terminal);
+               return syswarn_set(-ENODEV, "Failed to allocate proxy terminal");
        }
 
        return 0;
-
-err:
-       lxc_terminal_delete(terminal);
-       return -ENODEV;
 }
 
 int lxc_terminal_create(const char *name, const char *lxcpath,

diff --git a/src/lxc/terminal.h b/src/lxc/terminal.h
index 8bf2bda76b43f9b8127a6e1c711e0523370af106..4d2894fe79411a3cae0e70c08cf1474058595c71 100644 (file)
--- a/src/lxc/terminal.h
+++ b/src/lxc/terminal.h
@@ -252,5 +252,8 @@ __hidden extern void lxc_terminal_conf_free(struct lxc_terminal *terminal);
 __hidden extern void lxc_terminal_info_init(struct lxc_terminal_info *terminal);
 __hidden extern void lxc_terminal_init(struct lxc_terminal *terminal);
 __hidden extern int lxc_terminal_signal_sigmask_safe_blocked(struct lxc_terminal *terminal);
+__hidden extern int lxc_devpts_terminal(int devpts_fd, struct lxc_conf *conf,
+                                       int *ret_ptx, int *ret_pty,
+                                       char buf[static PATH_MAX]);
 
 #endif /* __LXC_TERMINAL_H */