1 /* $OpenBSD: cmd-pipe-pane.c,v 1.46 2017/07/14 18:49:07 nicm Exp $ */ 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_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 = { "ot:", 0, 1 }, 47 .usage = "[-o] " CMD_TARGET_PANE_USAGE " [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 = self->args; 59 struct client *c = cmd_find_client(item, NULL, 1); 60 struct window_pane *wp = item->target.wp; 61 struct session *s = item->target.s; 62 struct winlink *wl = item->target.wl; 63 char *cmd; 64 int old_fd, pipe_fd[2], null_fd; 65 struct format_tree *ft; 66 sigset_t set, oldset; 67 68 /* Destroy the old pipe. */ 69 old_fd = wp->pipe_fd; 70 if (wp->pipe_fd != -1) { 71 bufferevent_free(wp->pipe_event); 72 close(wp->pipe_fd); 73 wp->pipe_fd = -1; 74 75 if (window_pane_destroy_ready(wp)) { 76 server_destroy_pane(wp, 1); 77 return (CMD_RETURN_NORMAL); 78 } 79 } 80 81 /* If no pipe command, that is enough. */ 82 if (args->argc == 0 || *args->argv[0] == '\0') 83 return (CMD_RETURN_NORMAL); 84 85 /* 86 * With -o, only open the new pipe if there was no previous one. This 87 * allows a pipe to be toggled with a single key, for example: 88 * 89 * bind ^p pipep -o 'cat >>~/output' 90 */ 91 if (args_has(self->args, 'o') && old_fd != -1) 92 return (CMD_RETURN_NORMAL); 93 94 /* Open the new pipe. */ 95 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fd) != 0) { 96 cmdq_error(item, "socketpair error: %s", strerror(errno)); 97 return (CMD_RETURN_ERROR); 98 } 99 100 /* Expand the command. */ 101 ft = format_create(item->client, item, FORMAT_NONE, 0); 102 format_defaults(ft, c, s, wl, wp); 103 cmd = format_expand_time(ft, args->argv[0], time(NULL)); 104 format_free(ft); 105 106 /* Fork the child. */ 107 sigfillset(&set); 108 sigprocmask(SIG_BLOCK, &set, &oldset); 109 switch (fork()) { 110 case -1: 111 sigprocmask(SIG_SETMASK, &oldset, NULL); 112 cmdq_error(item, "fork error: %s", strerror(errno)); 113 114 free(cmd); 115 return (CMD_RETURN_ERROR); 116 case 0: 117 /* Child process. */ 118 proc_clear_signals(server_proc, 1); 119 sigprocmask(SIG_SETMASK, &oldset, NULL); 120 close(pipe_fd[0]); 121 122 if (dup2(pipe_fd[1], STDIN_FILENO) == -1) 123 _exit(1); 124 if (pipe_fd[1] != STDIN_FILENO) 125 close(pipe_fd[1]); 126 127 null_fd = open(_PATH_DEVNULL, O_WRONLY, 0); 128 if (dup2(null_fd, STDOUT_FILENO) == -1) 129 _exit(1); 130 if (dup2(null_fd, STDERR_FILENO) == -1) 131 _exit(1); 132 if (null_fd != STDOUT_FILENO && null_fd != STDERR_FILENO) 133 close(null_fd); 134 135 closefrom(STDERR_FILENO + 1); 136 137 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL); 138 _exit(1); 139 default: 140 /* Parent process. */ 141 sigprocmask(SIG_SETMASK, &oldset, NULL); 142 close(pipe_fd[1]); 143 144 wp->pipe_fd = pipe_fd[0]; 145 wp->pipe_off = EVBUFFER_LENGTH(wp->event->input); 146 147 wp->pipe_event = bufferevent_new(wp->pipe_fd, NULL, 148 cmd_pipe_pane_write_callback, cmd_pipe_pane_error_callback, 149 wp); 150 bufferevent_enable(wp->pipe_event, EV_WRITE); 151 152 setblocking(wp->pipe_fd, 0); 153 154 free(cmd); 155 return (CMD_RETURN_NORMAL); 156 } 157 } 158 159 static void 160 cmd_pipe_pane_write_callback(__unused struct bufferevent *bufev, void *data) 161 { 162 struct window_pane *wp = data; 163 164 log_debug("%%%u pipe empty", wp->id); 165 if (window_pane_destroy_ready(wp)) 166 server_destroy_pane(wp, 1); 167 } 168 169 static void 170 cmd_pipe_pane_error_callback(__unused struct bufferevent *bufev, 171 __unused short what, void *data) 172 { 173 struct window_pane *wp = data; 174 175 log_debug("%%%u pipe error", wp->id); 176 177 bufferevent_free(wp->pipe_event); 178 close(wp->pipe_fd); 179 wp->pipe_fd = -1; 180 181 if (window_pane_destroy_ready(wp)) 182 server_destroy_pane(wp, 1); 183 } 184