1/* $OpenBSD$ */
2
3/*
4 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/socket.h>
21
22#include <errno.h>
23#include <fcntl.h>
24#include <signal.h>
25#include <stdlib.h>
26#include <string.h>
27#include <time.h>
28#include <unistd.h>
29
30#include "tmux.h"
31
32/*
33 * Open pipe to redirect pane output. If already open, close first.
34 */
35
36static enum cmd_retval	cmd_pipe_pane_exec(struct cmd *, struct cmdq_item *);
37
38static void cmd_pipe_pane_read_callback(struct bufferevent *, void *);
39static void cmd_pipe_pane_write_callback(struct bufferevent *, void *);
40static void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
41
42const struct cmd_entry cmd_pipe_pane_entry = {
43	.name = "pipe-pane",
44	.alias = "pipep",
45
46	.args = { "IOot:", 0, 1, NULL },
47	.usage = "[-IOo] " CMD_TARGET_PANE_USAGE " [shell-command]",
48
49	.target = { 't', CMD_FIND_PANE, 0 },
50
51	.flags = CMD_AFTERHOOK,
52	.exec = cmd_pipe_pane_exec
53};
54
55static enum cmd_retval
56cmd_pipe_pane_exec(struct cmd *self, struct cmdq_item *item)
57{
58	struct args			*args = cmd_get_args(self);
59	struct cmd_find_state		*target = cmdq_get_target(item);
60	struct client			*tc = cmdq_get_target_client(item);
61	struct window_pane		*wp = target->wp;
62	struct session			*s = target->s;
63	struct winlink			*wl = target->wl;
64	struct window_pane_offset	*wpo = &wp->pipe_offset;
65	char				*cmd;
66	int				 old_fd, pipe_fd[2], null_fd, in, out;
67	struct format_tree		*ft;
68	sigset_t			 set, oldset;
69
70	/* Do nothing if pane is dead. */
71	if (wp->fd == -1 || (wp->flags & PANE_EXITED)) {
72		cmdq_error(item, "target pane has exited");
73		return (CMD_RETURN_ERROR);
74	}
75
76	/* Destroy the old pipe. */
77	old_fd = wp->pipe_fd;
78	if (wp->pipe_fd != -1) {
79		bufferevent_free(wp->pipe_event);
80		close(wp->pipe_fd);
81		wp->pipe_fd = -1;
82
83		if (window_pane_destroy_ready(wp)) {
84			server_destroy_pane(wp, 1);
85			return (CMD_RETURN_NORMAL);
86		}
87	}
88
89	/* If no pipe command, that is enough. */
90	if (args_count(args) == 0 || *args_string(args, 0) == '\0')
91		return (CMD_RETURN_NORMAL);
92
93	/*
94	 * With -o, only open the new pipe if there was no previous one. This
95	 * allows a pipe to be toggled with a single key, for example:
96	 *
97	 *	bind ^p pipep -o 'cat >>~/output'
98	 */
99	if (args_has(args, 'o') && old_fd != -1)
100		return (CMD_RETURN_NORMAL);
101
102	/* What do we want to do? Neither -I or -O is -O. */
103	if (args_has(args, 'I')) {
104		in = 1;
105		out = args_has(args, 'O');
106	} else {
107		in = 0;
108		out = 1;
109	}
110
111	/* Open the new pipe. */
112	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
113		cmdq_error(item, "socketpair error: %s", strerror(errno));
114		return (CMD_RETURN_ERROR);
115	}
116
117	/* Expand the command. */
118	ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
119	format_defaults(ft, tc, s, wl, wp);
120	cmd = format_expand_time(ft, args_string(args, 0));
121	format_free(ft);
122
123	/* Fork the child. */
124	sigfillset(&set);
125	sigprocmask(SIG_BLOCK, &set, &oldset);
126	switch (fork()) {
127	case -1:
128		sigprocmask(SIG_SETMASK, &oldset, NULL);
129		cmdq_error(item, "fork error: %s", strerror(errno));
130
131		free(cmd);
132		return (CMD_RETURN_ERROR);
133	case 0:
134		/* Child process. */
135		proc_clear_signals(server_proc, 1);
136		sigprocmask(SIG_SETMASK, &oldset, NULL);
137		close(pipe_fd[0]);
138
139		null_fd = open(_PATH_DEVNULL, O_WRONLY);
140		if (out) {
141			if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
142				_exit(1);
143		} else {
144			if (dup2(null_fd, STDIN_FILENO) == -1)
145				_exit(1);
146		}
147		if (in) {
148			if (dup2(pipe_fd[1], STDOUT_FILENO) == -1)
149				_exit(1);
150			if (pipe_fd[1] != STDOUT_FILENO)
151				close(pipe_fd[1]);
152		} else {
153			if (dup2(null_fd, STDOUT_FILENO) == -1)
154				_exit(1);
155		}
156		if (dup2(null_fd, STDERR_FILENO) == -1)
157			_exit(1);
158		closefrom(STDERR_FILENO + 1);
159
160		execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
161		_exit(1);
162	default:
163		/* Parent process. */
164		sigprocmask(SIG_SETMASK, &oldset, NULL);
165		close(pipe_fd[1]);
166
167		wp->pipe_fd = pipe_fd[0];
168		memcpy(wpo, &wp->offset, sizeof *wpo);
169
170		setblocking(wp->pipe_fd, 0);
171		wp->pipe_event = bufferevent_new(wp->pipe_fd,
172		    cmd_pipe_pane_read_callback,
173		    cmd_pipe_pane_write_callback,
174		    cmd_pipe_pane_error_callback,
175		    wp);
176		if (wp->pipe_event == NULL)
177			fatalx("out of memory");
178		if (out)
179			bufferevent_enable(wp->pipe_event, EV_WRITE);
180		if (in)
181			bufferevent_enable(wp->pipe_event, EV_READ);
182
183		free(cmd);
184		return (CMD_RETURN_NORMAL);
185	}
186}
187
188static void
189cmd_pipe_pane_read_callback(__unused struct bufferevent *bufev, void *data)
190{
191	struct window_pane	*wp = data;
192	struct evbuffer		*evb = wp->pipe_event->input;
193	size_t			 available;
194
195	available = EVBUFFER_LENGTH(evb);
196	log_debug("%%%u pipe read %zu", wp->id, available);
197
198	bufferevent_write(wp->event, EVBUFFER_DATA(evb), available);
199	evbuffer_drain(evb, available);
200
201	if (window_pane_destroy_ready(wp))
202		server_destroy_pane(wp, 1);
203}
204
205static void
206cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data)
207{
208	struct window_pane	*wp = data;
209
210	log_debug("%%%u pipe empty", wp->id);
211
212	if (window_pane_destroy_ready(wp))
213		server_destroy_pane(wp, 1);
214}
215
216static void
217cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev,
218    __unused short what, void *data)
219{
220	struct window_pane	*wp = data;
221
222	log_debug("%%%u pipe error", wp->id);
223
224	bufferevent_free(wp->pipe_event);
225	close(wp->pipe_fd);
226	wp->pipe_fd = -1;
227
228	if (window_pane_destroy_ready(wp))
229		server_destroy_pane(wp, 1);
230}
231