summaryrefslogtreecommitdiff
path: root/usr.bin/tmux/cmd-pipe-pane.c
blob: d7477b45675c94a3367053c1723f6e1d9798e071 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/* $OpenBSD: cmd-pipe-pane.c,v 1.53 2020/04/13 10:59:58 nicm Exp $ */

/*
 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>

#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "tmux.h"

/*
 * Open pipe to redirect pane output. If already open, close first.
 */

static enum cmd_retval	cmd_pipe_pane_exec(struct cmd *, struct cmdq_item *);

static void cmd_pipe_pane_read_callback(struct bufferevent *, void *);
static void cmd_pipe_pane_write_callback(struct bufferevent *, void *);
static void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);

const struct cmd_entry cmd_pipe_pane_entry = {
	.name = "pipe-pane",
	.alias = "pipep",

	.args = { "IOot:", 0, 1 },
	.usage = "[-IOo] " CMD_TARGET_PANE_USAGE " [command]",

	.target = { 't', CMD_FIND_PANE, 0 },

	.flags = CMD_AFTERHOOK,
	.exec = cmd_pipe_pane_exec
};

static enum cmd_retval
cmd_pipe_pane_exec(struct cmd *self, struct cmdq_item *item)
{
	struct args		*args = cmd_get_args(self);
	struct cmd_find_state	*target = cmdq_get_target(item);
	struct client		*c = cmd_find_client(item, NULL, 1);
	struct window_pane	*wp = target->wp;
	struct session		*s = target->s;
	struct winlink		*wl = target->wl;
	char			*cmd;
	int			 old_fd, pipe_fd[2], null_fd, in, out;
	struct format_tree	*ft;
	sigset_t		 set, oldset;

	/* Destroy the old pipe. */
	old_fd = wp->pipe_fd;
	if (wp->pipe_fd != -1) {
		bufferevent_free(wp->pipe_event);
		close(wp->pipe_fd);
		wp->pipe_fd = -1;

		if (window_pane_destroy_ready(wp)) {
			server_destroy_pane(wp, 1);
			return (CMD_RETURN_NORMAL);
		}
	}

	/* If no pipe command, that is enough. */
	if (args->argc == 0 || *args->argv[0] == '\0')
		return (CMD_RETURN_NORMAL);

	/*
	 * With -o, only open the new pipe if there was no previous one. This
	 * allows a pipe to be toggled with a single key, for example:
	 *
	 *	bind ^p pipep -o 'cat >>~/output'
	 */
	if (args_has(args, 'o') && old_fd != -1)
		return (CMD_RETURN_NORMAL);

	/* What do we want to do? Neither -I or -O is -O. */
	if (args_has(args, 'I')) {
		in = 1;
		out = args_has(args, 'O');
	} else {
		in = 0;
		out = 1;
	}

	/* Open the new pipe. */
	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
		cmdq_error(item, "socketpair error: %s", strerror(errno));
		return (CMD_RETURN_ERROR);
	}

	/* Expand the command. */
	ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
	format_defaults(ft, c, s, wl, wp);
	cmd = format_expand_time(ft, args->argv[0]);
	format_free(ft);

	/* Fork the child. */
	sigfillset(&set);
	sigprocmask(SIG_BLOCK, &set, &oldset);
	switch (fork()) {
	case -1:
		sigprocmask(SIG_SETMASK, &oldset, NULL);
		cmdq_error(item, "fork error: %s", strerror(errno));

		free(cmd);
		return (CMD_RETURN_ERROR);
	case 0:
		/* Child process. */
		proc_clear_signals(server_proc, 1);
		sigprocmask(SIG_SETMASK, &oldset, NULL);
		close(pipe_fd[0]);

		null_fd = open(_PATH_DEVNULL, O_WRONLY, 0);
		if (out) {
			if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
				_exit(1);
		} else {
			if (dup2(null_fd, STDIN_FILENO) == -1)
				_exit(1);
		}
		if (in) {
			if (dup2(pipe_fd[1], STDOUT_FILENO) == -1)
				_exit(1);
			if (pipe_fd[1] != STDOUT_FILENO)
				close(pipe_fd[1]);
		} else {
			if (dup2(null_fd, STDOUT_FILENO) == -1)
				_exit(1);
		}
		if (dup2(null_fd, STDERR_FILENO) == -1)
			_exit(1);
		closefrom(STDERR_FILENO + 1);

		execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
		_exit(1);
	default:
		/* Parent process. */
		sigprocmask(SIG_SETMASK, &oldset, NULL);
		close(pipe_fd[1]);

		wp->pipe_fd = pipe_fd[0];
		if (wp->fd != -1)
			wp->pipe_off = EVBUFFER_LENGTH(wp->event->input);
		else
			wp->pipe_off = 0;

		setblocking(wp->pipe_fd, 0);
		wp->pipe_event = bufferevent_new(wp->pipe_fd,
		    cmd_pipe_pane_read_callback,
		    cmd_pipe_pane_write_callback,
		    cmd_pipe_pane_error_callback,
		    wp);
		if (wp->pipe_event == NULL)
			fatalx("out of memory");
		if (out)
			bufferevent_enable(wp->pipe_event, EV_WRITE);
		if (in)
			bufferevent_enable(wp->pipe_event, EV_READ);

		free(cmd);
		return (CMD_RETURN_NORMAL);
	}
}

static void
cmd_pipe_pane_read_callback(__unused struct bufferevent *bufev, void *data)
{
	struct window_pane	*wp = data;
	struct evbuffer		*evb = wp->pipe_event->input;
	size_t			 available;

	available = EVBUFFER_LENGTH(evb);
	log_debug("%%%u pipe read %zu", wp->id, available);

	bufferevent_write(wp->event, EVBUFFER_DATA(evb), available);
	evbuffer_drain(evb, available);

	if (window_pane_destroy_ready(wp))
		server_destroy_pane(wp, 1);
}

static void
cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data)
{
	struct window_pane	*wp = data;

	log_debug("%%%u pipe empty", wp->id);

	if (window_pane_destroy_ready(wp))
		server_destroy_pane(wp, 1);
}

static void
cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev,
    __unused short what, void *data)
{
	struct window_pane	*wp = data;

	log_debug("%%%u pipe error", wp->id);

	bufferevent_free(wp->pipe_event);
	close(wp->pipe_fd);
	wp->pipe_fd = -1;

	if (window_pane_destroy_ready(wp))
		server_destroy_pane(wp, 1);
}