cmd-pipe-pane.c

   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
  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 (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
 188 static void
 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
 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
 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 }