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