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         /* Destroy the old pipe. */
  72         old_fd = wp->pipe_fd;
  73         if (wp->pipe_fd != -1) {
  74                 bufferevent_free(wp->pipe_event);
  75                 close(wp->pipe_fd);
  76                 wp->pipe_fd = -1;
  77
  78                 if (window_pane_destroy_ready(wp)) {
  79                         server_destroy_pane(wp, 1);
  80                         return (CMD_RETURN_NORMAL);
  81                 }
  82         }
  83
  84         /* If no pipe command, that is enough. */
  85         if (args_count(args) == 0 || *args_string(args, 0) == '\0')
  86                 return (CMD_RETURN_NORMAL);
  87
  88         /*
  89          * With -o, only open the new pipe if there was no previous one. This
  90          * allows a pipe to be toggled with a single key, for example:
  91          *
  92          *      bind ^p pipep -o 'cat >>~/output'
  93          */
  94         if (args_has(args, 'o') && old_fd != -1)
  95                 return (CMD_RETURN_NORMAL);
  96
  97         /* What do we want to do? Neither -I or -O is -O. */
  98         if (args_has(args, 'I')) {
  99                 in = 1;
 100                 out = args_has(args, 'O');
 101         } else {
 102                 in = 0;
 103                 out = 1;
 104         }
 105
 106         /* Open the new pipe. */
 107         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) {
 108                 cmdq_error(item, "socketpair error: %s", strerror(errno));
 109                 return (CMD_RETURN_ERROR);
 110         }
 111
 112         /* Expand the command. */
 113         ft = format_create(cmdq_get_client(item), item, FORMAT_NONE, 0);
 114         format_defaults(ft, tc, s, wl, wp);
 115         cmd = format_expand_time(ft, args_string(args, 0));
 116         format_free(ft);
 117
 118         /* Fork the child. */
 119         sigfillset(&set);
 120         sigprocmask(SIG_BLOCK, &set, &oldset);
 121         switch (fork()) {
 122         case -1:
 123                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 124                 cmdq_error(item, "fork error: %s", strerror(errno));
 125
 126                 free(cmd);
 127                 return (CMD_RETURN_ERROR);
 128         case 0:
 129                 /* Child process. */
 130                 proc_clear_signals(server_proc, 1);
 131                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 132                 close(pipe_fd[0]);
 133
 134                 null_fd = open(_PATH_DEVNULL, O_WRONLY);
 135                 if (out) {
 136                         if (dup2(pipe_fd[1], STDIN_FILENO) == -1)
 137                                 _exit(1);
 138                 } else {
 139                         if (dup2(null_fd, STDIN_FILENO) == -1)
 140                                 _exit(1);
 141                 }
 142                 if (in) {
 143                         if (dup2(pipe_fd[1], STDOUT_FILENO) == -1)
 144                                 _exit(1);
 145                         if (pipe_fd[1] != STDOUT_FILENO)
 146                                 close(pipe_fd[1]);
 147                 } else {
 148                         if (dup2(null_fd, STDOUT_FILENO) == -1)
 149                                 _exit(1);
 150                 }
 151                 if (dup2(null_fd, STDERR_FILENO) == -1)
 152                         _exit(1);
 153                 closefrom(STDERR_FILENO + 1);
 154
 155                 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
 156                 _exit(1);
 157         default:
 158                 /* Parent process. */
 159                 sigprocmask(SIG_SETMASK, &oldset, NULL);
 160                 close(pipe_fd[1]);
 161
 162                 wp->pipe_fd = pipe_fd[0];
 163                 memcpy(wpo, &wp->offset, sizeof *wpo);
 164
 165                 setblocking(wp->pipe_fd, 0);
 166                 wp->pipe_event = bufferevent_new(wp->pipe_fd,
 167                     cmd_pipe_pane_read_callback,
 168                     cmd_pipe_pane_write_callback,
 169                     cmd_pipe_pane_error_callback,
 170                     wp);
 171                 if (wp->pipe_event == NULL)
 172                         fatalx("out of memory");
 173                 if (out)
 174                         bufferevent_enable(wp->pipe_event, EV_WRITE);
 175                 if (in)
 176                         bufferevent_enable(wp->pipe_event, EV_READ);
 177
 178                 free(cmd);
 179                 return (CMD_RETURN_NORMAL);
 180         }
 181 }
 182
 183 static void
 184 cmd_pipe_pane_read_callback(__unused struct bufferevent *bufev, void *data)
 185 {
 186         struct window_pane      *wp = data;
 187         struct evbuffer         *evb = wp->pipe_event->input;
 188         size_t                   available;
 189
 190         available = EVBUFFER_LENGTH(evb);
 191         log_debug("%%%u pipe read %zu", wp->id, available);
 192
 193         bufferevent_write(wp->event, EVBUFFER_DATA(evb), available);
 194         evbuffer_drain(evb, available);
 195
 196         if (window_pane_destroy_ready(wp))
 197                 server_destroy_pane(wp, 1);
 198 }
 199
 200 static void
 201 cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data)
 202 {
 203         struct window_pane      *wp = data;
 204
 205         log_debug("%%%u pipe empty", wp->id);
 206
 207         if (window_pane_destroy_ready(wp))
 208                 server_destroy_pane(wp, 1);
 209 }
 210
 211 static void
 212 cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev,
 213     __unused short what, void *data)
 214 {
 215         struct window_pane      *wp = data;
 216
 217         log_debug("%%%u pipe error", wp->id);
 218
 219         bufferevent_free(wp->pipe_event);
 220         close(wp->pipe_fd);
 221         wp->pipe_fd = -1;
 222
 223         if (window_pane_destroy_ready(wp))
 224                 server_destroy_pane(wp, 1);
 225 }