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
36 static enum cmd_retval cmd_pipe_pane_exec(struct cmd *, struct cmdq_item *);
37
38 static void cmd_pipe_pane_read_callback(struct bufferevent *, void *);
39 static void cmd_pipe_pane_write_callback(struct bufferevent *, void *);
40 static void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
41
42 const 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
55 static enum cmd_retval
cmd_pipe_pane_exec(struct cmd * self,struct cmdq_item * item)56 cmd_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 (window_pane_exited(wp)) {
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
188 static void
cmd_pipe_pane_read_callback(__unused struct bufferevent * bufev,void * data)189 cmd_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
205 static void
cmd_pipe_pane_write_callback(__unused struct bufferevent * bufev,void * data)206 cmd_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
216 static void
cmd_pipe_pane_error_callback(__unused struct bufferevent * bufev,__unused short what,void * data)217 cmd_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