1 /* $OpenBSD: cmd-pipe-pane.c,v 1.55 2020/05/21 07:24:13 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_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 }, 48 .usage = "[-IOo] " CMD_TARGET_PANE_USAGE " [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->argc == 0 || *args->argv[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->argv[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, 0); 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 } 226