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 uid_t uid; 60 61 int flags; 62 #define PEER_BAD 0x1 63 64 void (*dispatchcb)(struct imsg *, void *); 65 void *arg; 66 67 TAILQ_ENTRY(tmuxpeer) entry; 68 }; 69 70 static int peer_check_version(struct tmuxpeer *, struct imsg *); 71 static void proc_update_event(struct tmuxpeer *); 72 73 static void 74 proc_event_cb(__unused int fd, short events, void *arg) 75 { 76 struct tmuxpeer *peer = arg; 77 ssize_t n; 78 struct imsg imsg; 79 80 if (!(peer->flags & PEER_BAD) && (events & EV_READ)) { 81 if (((n = imsg_read(&peer->ibuf)) == -1 && errno != EAGAIN) || 82 n == 0) { 83 peer->dispatchcb(NULL, peer->arg); 84 return; 85 } 86 for (;;) { 87 if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) { 88 peer->dispatchcb(NULL, peer->arg); 89 return; 90 } 91 if (n == 0) 92 break; 93 log_debug("peer %p message %d", peer, imsg.hdr.type); 94 95 if (peer_check_version(peer, &imsg) != 0) { 96 if (imsg.fd != -1) 97 close(imsg.fd); 98 imsg_free(&imsg); 99 break; 100 } 101 102 peer->dispatchcb(&imsg, peer->arg); 103 imsg_free(&imsg); 104 } 105 } 106 107 if (events & EV_WRITE) { 108 if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) { 109 peer->dispatchcb(NULL, peer->arg); 110 return; 111 } 112 } 113 114 if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) { 115 peer->dispatchcb(NULL, peer->arg); 116 return; 117 } 118 119 proc_update_event(peer); 120 } 121 122 static void 123 proc_signal_cb(int signo, __unused short events, void *arg) 124 { 125 struct tmuxproc *tp = arg; 126 127 tp->signalcb(signo); 128 } 129 130 static int 131 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg) 132 { 133 int version; 134 135 version = imsg->hdr.peerid & 0xff; 136 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) { 137 log_debug("peer %p bad version %d", peer, version); 138 139 proc_send(peer, MSG_VERSION, -1, NULL, 0); 140 peer->flags |= PEER_BAD; 141 142 return (-1); 143 } 144 return (0); 145 } 146 147 static void 148 proc_update_event(struct tmuxpeer *peer) 149 { 150 short events; 151 152 event_del(&peer->event); 153 154 events = EV_READ; 155 if (peer->ibuf.w.queued > 0) 156 events |= EV_WRITE; 157 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer); 158 159 event_add(&peer->event, NULL); 160 } 161 162 int 163 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf, 164 size_t len) 165 { 166 struct imsgbuf *ibuf = &peer->ibuf; 167 void *vp = __UNCONST(buf); 168 int retval; 169 170 if (peer->flags & PEER_BAD) 171 return (-1); 172 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len); 173 174 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len); 175 if (retval != 1) 176 return (-1); 177 proc_update_event(peer); 178 return (0); 179 } 180 181 struct tmuxproc * 182 proc_start(const char *name) 183 { 184 struct tmuxproc *tp; 185 struct utsname u; 186 187 log_open(name); 188 setproctitle("%s (%s)", name, socket_path); 189 190 if (uname(&u) < 0) 191 memset(&u, 0, sizeof u); 192 193 log_debug("%s started (%ld): version %s, socket %s, protocol %d", name, 194 (long)getpid(), getversion(), socket_path, PROTOCOL_VERSION); 195 log_debug("on %s %s %s", u.sysname, u.release, u.version); 196 log_debug("using libevent %s (%s)" 197 #ifdef HAVE_UTF8PROC 198 "; utf8proc %s" 199 #endif 200 #ifdef NCURSES_VERSION 201 "; ncurses " NCURSES_VERSION 202 #endif 203 , event_get_version(), event_get_method() 204 #ifdef HAVE_UTF8PROC 205 , utf8proc_version() 206 #endif 207 ); 208 209 tp = xcalloc(1, sizeof *tp); 210 tp->name = xstrdup(name); 211 TAILQ_INIT(&tp->peers); 212 213 return (tp); 214 } 215 216 void 217 proc_loop(struct tmuxproc *tp, int (*loopcb)(void)) 218 { 219 log_debug("%s loop enter", tp->name); 220 do 221 event_loop(EVLOOP_ONCE); 222 while (!tp->exit && (loopcb == NULL || !loopcb ())); 223 log_debug("%s loop exit", tp->name); 224 } 225 226 void 227 proc_exit(struct tmuxproc *tp) 228 { 229 struct tmuxpeer *peer; 230 231 TAILQ_FOREACH(peer, &tp->peers, entry) 232 imsg_flush(&peer->ibuf); 233 tp->exit = 1; 234 } 235 236 void 237 proc_set_signals(struct tmuxproc *tp, void (*signalcb)(int)) 238 { 239 struct sigaction sa; 240 241 tp->signalcb = signalcb; 242 243 memset(&sa, 0, sizeof sa); 244 sigemptyset(&sa.sa_mask); 245 sa.sa_flags = SA_RESTART; 246 sa.sa_handler = SIG_IGN; 247 248 sigaction(SIGPIPE, &sa, NULL); 249 sigaction(SIGTSTP, &sa, NULL); 250 sigaction(SIGTTIN, &sa, NULL); 251 sigaction(SIGTTOU, &sa, NULL); 252 sigaction(SIGQUIT, &sa, NULL); 253 254 signal_set(&tp->ev_sigint, SIGINT, proc_signal_cb, tp); 255 signal_add(&tp->ev_sigint, NULL); 256 signal_set(&tp->ev_sighup, SIGHUP, proc_signal_cb, tp); 257 signal_add(&tp->ev_sighup, NULL); 258 signal_set(&tp->ev_sigchld, SIGCHLD, proc_signal_cb, tp); 259 signal_add(&tp->ev_sigchld, NULL); 260 signal_set(&tp->ev_sigcont, SIGCONT, proc_signal_cb, tp); 261 signal_add(&tp->ev_sigcont, NULL); 262 signal_set(&tp->ev_sigterm, SIGTERM, proc_signal_cb, tp); 263 signal_add(&tp->ev_sigterm, NULL); 264 signal_set(&tp->ev_sigusr1, SIGUSR1, proc_signal_cb, tp); 265 signal_add(&tp->ev_sigusr1, NULL); 266 signal_set(&tp->ev_sigusr2, SIGUSR2, proc_signal_cb, tp); 267 signal_add(&tp->ev_sigusr2, NULL); 268 signal_set(&tp->ev_sigwinch, SIGWINCH, proc_signal_cb, tp); 269 signal_add(&tp->ev_sigwinch, NULL); 270 } 271 272 void 273 proc_clear_signals(struct tmuxproc *tp, int defaults) 274 { 275 struct sigaction sa; 276 277 memset(&sa, 0, sizeof sa); 278 sigemptyset(&sa.sa_mask); 279 sa.sa_flags = SA_RESTART; 280 sa.sa_handler = SIG_DFL; 281 282 sigaction(SIGPIPE, &sa, NULL); 283 sigaction(SIGTSTP, &sa, NULL); 284 285 signal_del(&tp->ev_sigint); 286 signal_del(&tp->ev_sighup); 287 signal_del(&tp->ev_sigchld); 288 signal_del(&tp->ev_sigcont); 289 signal_del(&tp->ev_sigterm); 290 signal_del(&tp->ev_sigusr1); 291 signal_del(&tp->ev_sigusr2); 292 signal_del(&tp->ev_sigwinch); 293 294 if (defaults) { 295 sigaction(SIGINT, &sa, NULL); 296 sigaction(SIGQUIT, &sa, NULL); 297 sigaction(SIGHUP, &sa, NULL); 298 sigaction(SIGCHLD, &sa, NULL); 299 sigaction(SIGCONT, &sa, NULL); 300 sigaction(SIGTERM, &sa, NULL); 301 sigaction(SIGUSR1, &sa, NULL); 302 sigaction(SIGUSR2, &sa, NULL); 303 sigaction(SIGWINCH, &sa, NULL); 304 } 305 } 306 307 struct tmuxpeer * 308 proc_add_peer(struct tmuxproc *tp, int fd, 309 void (*dispatchcb)(struct imsg *, void *), void *arg) 310 { 311 struct tmuxpeer *peer; 312 gid_t gid; 313 314 peer = xcalloc(1, sizeof *peer); 315 peer->parent = tp; 316 317 peer->dispatchcb = dispatchcb; 318 peer->arg = arg; 319 320 imsg_init(&peer->ibuf, fd); 321 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer); 322 323 if (getpeereid(fd, &peer->uid, &gid) != 0) 324 peer->uid = (uid_t)-1; 325 326 log_debug("add peer %p: %d (%p)", peer, fd, arg); 327 TAILQ_INSERT_TAIL(&tp->peers, peer, entry); 328 329 proc_update_event(peer); 330 return (peer); 331 } 332 333 void 334 proc_remove_peer(struct tmuxpeer *peer) 335 { 336 TAILQ_REMOVE(&peer->parent->peers, peer, entry); 337 log_debug("remove peer %p", peer); 338 339 event_del(&peer->event); 340 imsg_clear(&peer->ibuf); 341 342 close(peer->ibuf.fd); 343 free(peer); 344 } 345 346 void 347 proc_kill_peer(struct tmuxpeer *peer) 348 { 349 peer->flags |= PEER_BAD; 350 } 351 352 void 353 proc_flush_peer(struct tmuxpeer *peer) 354 { 355 imsg_flush(&peer->ibuf); 356 } 357 358 void 359 proc_toggle_log(struct tmuxproc *tp) 360 { 361 log_toggle(tp->name); 362 } 363 364 pid_t 365 proc_fork_and_daemon(int *fd) 366 { 367 pid_t pid; 368 int pair[2]; 369 370 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 371 fatal("socketpair failed"); 372 switch (pid = fork()) { 373 case -1: 374 fatal("fork failed"); 375 case 0: 376 close(pair[0]); 377 *fd = pair[1]; 378 if (daemon(1, 0) != 0) 379 fatal("daemon failed"); 380 return (0); 381 default: 382 close(pair[1]); 383 *fd = pair[0]; 384 return (pid); 385 } 386 } 387 388 uid_t 389 proc_get_peer_uid(struct tmuxpeer *peer) 390 { 391 return (peer->uid); 392 } 393