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 <paths.h>
  25 #include <signal.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <time.h>
  29 #include <unistd.h>
  30
  31 #include "tmux.h"
  32
  33 /*
  34  * Open pipe to redirect pane output. If already open, close first.
  35  */
  36
  37 static enum cmd_retval  cmd_pipe_pane_exec(struct cmd *, struct cmdq_item *);
  38
  39 static void cmd_pipe_pane_read_callback(struct bufferevent *, void *);
  40 static void cmd_pipe_pane_write_callback(struct bufferevent *, void *);
  41 static void cmd_pipe_pane_error_callback(struct bufferevent *, short, void *);
  42
  43 const struct cmd_entry cmd_pipe_pane_entry = {
  44         .name = "pipe-pane",
  45         .alias = "pipep",
  46
  47         .args = { "IOot:", 0, 1, NULL },
  48         .usage = "[-IOo] " CMD_TARGET_PANE_USAGE " [shell-command]",
  49
  50         .target = { 't', CMD_FIND_PANE, 0 },
  51
  52         .flags = CMD_AFTERHOOK,
  53         .exec = cmd_pipe_pane_exec
  54 };
  55
  56 static enum cmd_retval
  57 cmd_pipe_pane_exec(struct cmd *self, struct cmdq_item *item)
  58 {
  59         struct args                     *args = cmd_get_args(self);
  60         struct cmd_find_state           *target = cmdq_get_target(item);
  61         struct client                   *tc = cmdq_get_target_client(item);
  62         struct window_pane              *wp = target->wp;
  63         struct session                  *s = target->s;
  64         struct winlink                  *wl = target->wl;
  65         struct window_pane_offset       *wpo = &wp->pipe_offset;
  66         char                            *cmd;
  67         int                              old_fd, pipe_fd[2], null_fd, in, out;
  68         struct format_tree              *ft;
  69         sigset_t                         set, oldset;
  70
  71         /* Do nothing if pane is dead. */
  72         if (window_pane_exited(wp)) {
  73                 cmdq_error(item, "target pane has exited");
  74                 return (CMD_RETURN_ERROR);
  75         }
  76
  77         /* Destroy the old pipe. */
  78         old_fd = wp->pipe_fd;
  79         if (wp->pipe_fd != -1) {
  80                 bufferevent_free(wp->pipe_event);
  81                 close(wp->pipe_fd);
  82                 wp->pipe_fd = -1;
  83
  84                 if (window_pane_destroy_ready(wp)) {
  85                         server_destroy_pane(wp, 1);
  86                         return (CMD_RETURN_NORMAL);
  87                 }
  88         }
  89
  90         /* If no pipe command, that is enough. */
  91         if (args_count(args) == 0 || *args_string(args, 0) == '\0')
  92                 return (CMD_RETURN_NORMAL);
  93
  94         /*
  95          * With -o, only open the new pipe if there was no previous one. This
  96          * allows a pipe to be toggled with a single key, for example:
  97          *
  98          *      bind ^p pipep -o 'cat >>~/output'
  99          */
 100         if (args_has(args, 'o') && old_fd != -1)
 101                 return (CMD_RETURN_NORMAL);
 102
 103         /* What do we want to do? Neither -I or -O is -O. */
 104         if (args_has(args, 'I')) {
 105                 in = 1;
 106                 out = args_has(args, 'O');
 107         } else {
 108                 in = 0;
 109                 out = 1;
 110         }
 111
 112         /* Open the new pipe. */
 113         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
 114                 cmdq_error(item, "socketpair error: %s", strerror(errno));
 115                 return (CMD_RETURN_ERROR);
 116         }
 117
 118         /* Expand the command. */
 119         ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
 120         format_defaults(ft, tc, s, wl, wp);
 121         cmd = format_expand_time(ft, args_string(args, 0));
 122         format_free(ft);
 123
 124         /* Fork the child. */
 125         sigfillset(&set);
 126         sigprocmask(SIG_BLOCK, &set, &oldset);
 127         switch (fork()) {
 128         case -1:
 129                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 130                 cmdq_error(item, "fork error: %s", strerror(errno));
 131
 132                 free(cmd);
 133                 return (CMD_RETURN_ERROR);
 134         case 0:
 135                 /* Child process. */
 136                 proc_clear_signals(server_proc, 1);
 137                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 138                 close(pipe_fd[0]);
 139
 140                 null_fd = open(_PATH_DEVNULL, O_WRONLY);
 141                 if (out) {
 142                         if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
 143                                 _exit(1);
 144                 } else {
 145                         if (dup2(null_fd, STDIN_FILENO) == -1)
 146                                 _exit(1);
 147                 }
 148                 if (in) {
 149                         if (dup2(pipe_fd[1], STDOUT_FILENO) == -1)
 150                                 _exit(1);
 151                         if (pipe_fd[1] != STDOUT_FILENO)
 152                                 close(pipe_fd[1]);
 153                 } else {
 154                         if (dup2(null_fd, STDOUT_FILENO) == -1)
 155                                 _exit(1);
 156                 }
 157                 if (dup2(null_fd, STDERR_FILENO) == -1)
 158                         _exit(1);
 159                 closefrom(STDERR_FILENO + 1);
 160
 161                 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
 162                 _exit(1);
 163         default:
 164                 /* Parent process. */
 165                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 166                 close(pipe_fd[1]);
 167
 168                 wp->pipe_fd = pipe_fd[0];
 169                 memcpy(wpo, &wp->offset, sizeof *wpo);
 170
 171                 setblocking(wp->pipe_fd, 0);
 172                 wp->pipe_event = bufferevent_new(wp->pipe_fd,
 173                     cmd_pipe_pane_read_callback,
 174                     cmd_pipe_pane_write_callback,
 175                     cmd_pipe_pane_error_callback,
 176                     wp);
 177                 if (wp->pipe_event == NULL)
 178                         fatalx("out of memory");
 179                 if (out)
 180                         bufferevent_enable(wp->pipe_event, EV_WRITE);
 181                 if (in)
 182                         bufferevent_enable(wp->pipe_event, EV_READ);
 183
 184                 free(cmd);
 185                 return (CMD_RETURN_NORMAL);
 186         }
 187 }
 188
 189 static void
 190 cmd_pipe_pane_read_callback(__unused struct bufferevent *bufev, void *data)
 191 {
 192         struct window_pane      *wp = data;
 193         struct evbuffer         *evb = wp->pipe_event->input;
 194         size_t                   available;
 195
 196         available = EVBUFFER_LENGTH(evb);
 197         log_debug("%%%u pipe read %zu", wp->id, available);
 198
 199         bufferevent_write(wp->event, EVBUFFER_DATA(evb), available);
 200         evbuffer_drain(evb, available);
 201
 202         if (window_pane_destroy_ready(wp))
 203                 server_destroy_pane(wp, 1);
 204 }
 205
 206 static void
 207 cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data)
 208 {
 209         struct window_pane      *wp = data;
 210
 211         log_debug("%%%u pipe empty", wp->id);
 212
 213         if (window_pane_destroy_ready(wp))
 214                 server_destroy_pane(wp, 1);
 215 }
 216
 217 static void
 218 cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev,
 219     __unused short what, void *data)
 220 {
 221         struct window_pane      *wp = data;
 222
 223         log_debug("%%%u pipe error", wp->id);
 224
 225         bufferevent_free(wp->pipe_event);
 226         close(wp->pipe_fd);
 227         wp->pipe_fd = -1;
 228
 229         if (window_pane_destroy_ready(wp))
 230                 server_destroy_pane(wp, 1);
 231 }