1 /* $OpenBSD$ */ 2 3 /* 4 * Copyright (c) 2015 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 #include <sys/uio.h> 22 #include <sys/utsname.h> 23 24 #include <errno.h> 25 #include <signal.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <unistd.h> 29 30 #if defined(HAVE_NCURSES_H) 31 #include <ncurses.h> 32 #endif 33 34 #include "tmux.h" 35 36 struct tmuxproc { 37 const char *name; 38 int exit; 39 40 void (*signalcb)(int); 41 42 struct event ev_sigint; 43 struct event ev_sighup; 44 struct event ev_sigchld; 45 struct event ev_sigcont; 46 struct event ev_sigterm; 47 struct event ev_sigusr1; 48 struct event ev_sigusr2; 49 struct event ev_sigwinch; 50 51 TAILQ_HEAD(, tmuxpeer) peers; 52 }; 53 54 struct tmuxpeer { 55 struct tmuxproc *parent; 56 57 struct imsgbuf ibuf; 58 struct event event; 59 60 int flags; 61 #define PEER_BAD 0x1 62 63 void (*dispatchcb)(struct imsg *, void *); 64 void *arg; 65 66 TAILQ_ENTRY(tmuxpeer) entry; 67 }; 68 69 static int peer_check_version(struct tmuxpeer *, struct imsg *); 70 static void proc_update_event(struct tmuxpeer *); 71 72 static void 73 proc_event_cb(__unused int fd, short events, void *arg) 74 { 75 struct tmuxpeer *peer = arg; 76 ssize_t n; 77 struct imsg imsg; 78 79 if (!(peer->flags & PEER_BAD) && (events & EV_READ)) { 80 if (((n = imsg_read(&peer->ibuf)) == -1 && errno != EAGAIN) || 81 n == 0) { 82 peer->dispatchcb(NULL, peer->arg); 83 return; 84 } 85 for (;;) { 86 if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) { 87 peer->dispatchcb(NULL, peer->arg); 88 return; 89 } 90 if (n == 0) 91 break; 92 log_debug("peer %p message %d", peer, imsg.hdr.type); 93 94 if (peer_check_version(peer, &imsg) != 0) { 95 if (imsg.fd != -1) 96 close(imsg.fd); 97 imsg_free(&imsg); 98 break; 99 } 100 101 peer->dispatchcb(&imsg, peer->arg); 102 imsg_free(&imsg); 103 } 104 } 105 106 if (events & EV_WRITE) { 107 if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) { 108 peer->dispatchcb(NULL, peer->arg); 109 return; 110 } 111 } 112 113 if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) { 114 peer->dispatchcb(NULL, peer->arg); 115 return; 116 } 117 118 proc_update_event(peer); 119 } 120 121 static void 122 proc_signal_cb(int signo, __unused short events, void *arg) 123 { 124 struct tmuxproc *tp = arg; 125 126 tp->signalcb(signo); 127 } 128 129 static int 130 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg) 131 { 132 int version; 133 134 version = imsg->hdr.peerid & 0xff; 135 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) { 136 log_debug("peer %p bad version %d", peer, version); 137 138 proc_send(peer, MSG_VERSION, -1, NULL, 0); 139 peer->flags |= PEER_BAD; 140 141 return (-1); 142 } 143 return (0); 144 } 145 146 static void 147 proc_update_event(struct tmuxpeer *peer) 148 { 149 short events; 150 151 event_del(&peer->event); 152 153 events = EV_READ; 154 if (peer->ibuf.w.queued > 0) 155 events |= EV_WRITE; 156 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer); 157 158 event_add(&peer->event, NULL); 159 } 160 161 int 162 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf, 163 size_t len) 164 { 165 struct imsgbuf *ibuf = &peer->ibuf; 166 void *vp = __UNCONST(buf); 167 int retval; 168 169 if (peer->flags & PEER_BAD) 170 return (-1); 171 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len); 172 173 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len); 174 if (retval != 1) 175 return (-1); 176 proc_update_event(peer); 177 return (0); 178 } 179 180 struct tmuxproc * 181 proc_start(const char *name) 182 { 183 struct tmuxproc *tp; 184 struct utsname u; 185 186 log_open(name); 187 setproctitle("%s (%s)", name, socket_path); 188 189 if (uname(&u) < 0) 190 memset(&u, 0, sizeof u); 191 192 log_debug("%s started (%ld): version %s, socket %s, protocol %d", name, 193 (long)getpid(), getversion(), socket_path, PROTOCOL_VERSION); 194 log_debug("on %s %s %s", u.sysname, u.release, u.version); 195 log_debug("using libevent %s (%s)" 196 #ifdef HAVE_UTF8PROC 197 "; utf8proc %s" 198 #endif 199 #ifdef NCURSES_VERSION 200 "; ncurses " NCURSES_VERSION 201 #endif 202 , event_get_version(), event_get_method() 203 #ifdef HAVE_UTF8PROC 204 , utf8proc_version () 205 #endif 206 ); 207 208 tp = xcalloc(1, sizeof *tp); 209 tp->name = xstrdup(name); 210 TAILQ_INIT(&tp->peers); 211 212 return (tp); 213 } 214 215 void 216 proc_loop(struct tmuxproc *tp, int (*loopcb)(void)) 217 { 218 log_debug("%s loop enter", tp->name); 219 do 220 event_loop(EVLOOP_ONCE); 221 while (!tp->exit && (loopcb == NULL || !loopcb ())); 222 log_debug("%s loop exit", tp->name); 223 } 224 225 void 226 proc_exit(struct tmuxproc *tp) 227 { 228 struct tmuxpeer *peer; 229 230 TAILQ_FOREACH(peer, &tp->peers, entry) 231 imsg_flush(&peer->ibuf); 232 tp->exit = 1; 233 } 234 235 void 236 proc_set_signals(struct tmuxproc *tp, void (*signalcb)(int)) 237 { 238 struct sigaction sa; 239 240 tp->signalcb = signalcb; 241 242 memset(&sa, 0, sizeof sa); 243 sigemptyset(&sa.sa_mask); 244 sa.sa_flags = SA_RESTART; 245 sa.sa_handler = SIG_IGN; 246 247 sigaction(SIGPIPE, &sa, NULL); 248 sigaction(SIGTSTP, &sa, NULL); 249 sigaction(SIGTTIN, &sa, NULL); 250 sigaction(SIGTTOU, &sa, NULL); 251 sigaction(SIGQUIT, &sa, NULL); 252 253 signal_set(&tp->ev_sigint, SIGINT, proc_signal_cb, tp); 254 signal_add(&tp->ev_sigint, NULL); 255 signal_set(&tp->ev_sighup, SIGHUP, proc_signal_cb, tp); 256 signal_add(&tp->ev_sighup, NULL); 257 signal_set(&tp->ev_sigchld, SIGCHLD, proc_signal_cb, tp); 258 signal_add(&tp->ev_sigchld, NULL); 259 signal_set(&tp->ev_sigcont, SIGCONT, proc_signal_cb, tp); 260 signal_add(&tp->ev_sigcont, NULL); 261 signal_set(&tp->ev_sigterm, SIGTERM, proc_signal_cb, tp); 262 signal_add(&tp->ev_sigterm, NULL); 263 signal_set(&tp->ev_sigusr1, SIGUSR1, proc_signal_cb, tp); 264 signal_add(&tp->ev_sigusr1, NULL); 265 signal_set(&tp->ev_sigusr2, SIGUSR2, proc_signal_cb, tp); 266 signal_add(&tp->ev_sigusr2, NULL); 267 signal_set(&tp->ev_sigwinch, SIGWINCH, proc_signal_cb, tp); 268 signal_add(&tp->ev_sigwinch, NULL); 269 } 270 271 void 272 proc_clear_signals(struct tmuxproc *tp, int defaults) 273 { 274 struct sigaction sa; 275 276 memset(&sa, 0, sizeof sa); 277 sigemptyset(&sa.sa_mask); 278 sa.sa_flags = SA_RESTART; 279 sa.sa_handler = SIG_DFL; 280 281 sigaction(SIGPIPE, &sa, NULL); 282 sigaction(SIGTSTP, &sa, NULL); 283 284 signal_del(&tp->ev_sigint); 285 signal_del(&tp->ev_sighup); 286 signal_del(&tp->ev_sigchld); 287 signal_del(&tp->ev_sigcont); 288 signal_del(&tp->ev_sigterm); 289 signal_del(&tp->ev_sigusr1); 290 signal_del(&tp->ev_sigusr2); 291 signal_del(&tp->ev_sigwinch); 292 293 if (defaults) { 294 sigaction(SIGINT, &sa, NULL); 295 sigaction(SIGQUIT, &sa, NULL); 296 sigaction(SIGHUP, &sa, NULL); 297 sigaction(SIGCHLD, &sa, NULL); 298 sigaction(SIGCONT, &sa, NULL); 299 sigaction(SIGTERM, &sa, NULL); 300 sigaction(SIGUSR1, &sa, NULL); 301 sigaction(SIGUSR2, &sa, NULL); 302 sigaction(SIGWINCH, &sa, NULL); 303 } 304 } 305 306 struct tmuxpeer * 307 proc_add_peer(struct tmuxproc *tp, int fd, 308 void (*dispatchcb)(struct imsg *, void *), void *arg) 309 { 310 struct tmuxpeer *peer; 311 312 peer = xcalloc(1, sizeof *peer); 313 peer->parent = tp; 314 315 peer->dispatchcb = dispatchcb; 316 peer->arg = arg; 317 318 imsg_init(&peer->ibuf, fd); 319 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer); 320 321 log_debug("add peer %p: %d (%p)", peer, fd, arg); 322 TAILQ_INSERT_TAIL(&tp->peers, peer, entry); 323 324 proc_update_event(peer); 325 return (peer); 326 } 327 328 void 329 proc_remove_peer(struct tmuxpeer *peer) 330 { 331 TAILQ_REMOVE(&peer->parent->peers, peer, entry); 332 log_debug("remove peer %p", peer); 333 334 event_del(&peer->event); 335 imsg_clear(&peer->ibuf); 336 337 close(peer->ibuf.fd); 338 free(peer); 339 } 340 341 void 342 proc_kill_peer(struct tmuxpeer *peer) 343 { 344 peer->flags |= PEER_BAD; 345 } 346 347 void 348 proc_toggle_log(struct tmuxproc *tp) 349 { 350 log_toggle(tp->name); 351 } 352 353 pid_t 354 proc_fork_and_daemon(int *fd) 355 { 356 pid_t pid; 357 int pair[2]; 358 359 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 360 fatal("socketpair failed"); 361 switch (pid = fork()) { 362 case -1: 363 fatal("fork failed"); 364 case 0: 365 close(pair[0]); 366 *fd = pair[1]; 367 if (daemon(1, 0) != 0) 368 fatal("daemon failed"); 369 return (0); 370 default: 371 close(pair[1]); 372 *fd = pair[0]; 373 return (pid); 374 } 375 } 376