1  /*
       2   * This code is in the public domain; do with it what you wish.
       3   *
       4   * Written by Karel Zak <kzak@redhat.com> in Jul 2019
       5   */
       6  #ifndef UTIL_LINUX_PTY_SESSION_H
       7  #define UTIL_LINUX_PTY_SESSION_H
       8  
       9  #include <pty.h>
      10  #include <termios.h>
      11  #include <signal.h>
      12  #include <sys/time.h>
      13  #include <sys/stat.h>
      14  
      15  #include <sys/signalfd.h>
      16  
      17  /*
      18   * Callbacks -- the first argument is always callback data, see
      19   * ul_pty_set_callback_data().
      20   */
      21  struct ul_pty_callbacks {
      22  	/*
      23  	 * Optional. Executed on SIGCHLD when ssi_code is EXITED, KILLED or
      24  	 * DUMPED; The callback has to call ul_pty_set_child(pty, (pid_t) -1)
      25  	 * if child is no more alive.
      26  	 */
      27  	void (*child_wait)(void *, pid_t);
      28  
      29  	/*
      30  	 * Used when child_wait() undefined to informa about child status
      31  	 */
      32  	void (*child_die)(void *, pid_t, int);
      33  
      34  	/*
      35  	 * Executed on SIGCHLD when ssi_status is SIGSTOP
      36  	 */
      37  	void (*child_sigstop)(void *, pid_t);
      38  
      39  	/*
      40  	 * Executed in master loop before ul_pty enter poll() and in time set by
      41  	 * ul_pty_set_mainloop_time(). The callback is no used when time is not set.
      42  	 */
      43  	int (*mainloop)(void *);
      44  
      45  	/*
      46  	 * Executed on master or stdin activity, arguments:
      47  	 *   2nd - file descriptor
      48  	 *   3rd - buffer with data
      49  	 *   4th - size of the data
      50  	 */
      51  	int (*log_stream_activity)(void *, int, char *, size_t);
      52  
      53  	/*
      54  	 * Executed on signal, arguments:
      55  	 *   2nd - signal info
      56  	 *   3rd - NULL or signal specific data (e.g. struct winsize on SIGWINCH
      57  	 */
      58  	int (*log_signal)(void *, struct signalfd_siginfo *, void *);
      59  
      60  	/*
      61  	 * Executed on SIGUSR1
      62  	 */
      63  	int (*flush_logs)(void *);
      64  };
      65  
      66  struct ul_pty {
      67  	struct termios	stdin_attrs;	/* stdin and slave terminal runtime attributes */
      68  	int		master;		/* parent side */
      69  	int		slave;		/* child side */
      70  	int		sigfd;		/* signalfd() */
      71  	int		poll_timeout;
      72  	struct winsize	win;		/* terminal window size */
      73  	sigset_t	orgsig;		/* original signal mask */
      74  
      75  	int		delivered_signal;
      76  
      77  	struct ul_pty_callbacks	callbacks;
      78  	void			*callback_data;
      79  
      80  	pid_t		child;
      81  
      82  	struct timeval	next_callback_time;
      83  
      84  	struct ul_pty_child_buffer {
      85  		struct ul_pty_child_buffer *next;
      86  		char buf[BUFSIZ];
      87  		size_t size, cursor;
      88  		unsigned int final_input:1;	/* drain child before writing */
      89  	} *child_buffer_head, *child_buffer_tail, *free_buffers;
      90  
      91  	unsigned int isterm:1,		/* is stdin terminal? */
      92  		     slave_echo:1;	/* keep ECHO on pty slave */
      93  };
      94  
      95  void ul_pty_init_debug(int mask);
      96  struct ul_pty *ul_new_pty(int is_stdin_tty);
      97  void ul_free_pty(struct ul_pty *pty);
      98  
      99  void ul_pty_slave_echo(struct ul_pty *pty, int enable);
     100  int ul_pty_get_delivered_signal(struct ul_pty *pty);
     101  
     102  void ul_pty_set_callback_data(struct ul_pty *pty, void *data);
     103  void ul_pty_set_child(struct ul_pty *pty, pid_t child);
     104  
     105  struct ul_pty_callbacks *ul_pty_get_callbacks(struct ul_pty *pty);
     106  int ul_pty_is_running(struct ul_pty *pty);
     107  int ul_pty_setup(struct ul_pty *pty);
     108  int ul_pty_signals_setup(struct ul_pty *pty);
     109  void ul_pty_cleanup(struct ul_pty *pty);
     110  int ul_pty_chownmod_slave(struct ul_pty *pty, uid_t uid, gid_t gid, mode_t mode);
     111  void ul_pty_init_slave(struct ul_pty *pty);
     112  int ul_pty_proxy_master(struct ul_pty *pty);
     113  
     114  void ul_pty_set_mainloop_time(struct ul_pty *pty, struct timeval *tv);
     115  int ul_pty_get_childfd(struct ul_pty *pty);
     116  void ul_pty_wait_for_child(struct ul_pty *pty);
     117  pid_t ul_pty_get_child(struct ul_pty *pty);
     118  void ul_pty_write_eof_to_child(struct ul_pty *pty);
     119  
     120  #endif /* UTIL_LINUX_PTY_H */