1 /* $OpenBSD: proc.c,v 1.6 2015/11/24 21:32:36 nicm Exp $ */ 2 3 /* 4 * Copyright (c) 2015 Nicholas Marriott <nicm@users.sourceforge.net> 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/queue.h> 21 #include <sys/uio.h> 22 #include <sys/utsname.h> 23 24 #include <errno.h> 25 #include <event.h> 26 #include <imsg.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <unistd.h> 30 31 #include "tmux.h" 32 33 struct tmuxproc { 34 const char *name; 35 int exit; 36 37 void (*signalcb)(int); 38 }; 39 40 struct tmuxpeer { 41 struct tmuxproc *parent; 42 43 struct imsgbuf ibuf; 44 struct event event; 45 46 int flags; 47 #define PEER_BAD 0x1 48 49 void (*dispatchcb)(struct imsg *, void *); 50 void *arg; 51 }; 52 53 static int peer_check_version(struct tmuxpeer *, struct imsg *); 54 static void proc_update_event(struct tmuxpeer *); 55 56 static void 57 proc_event_cb(__unused int fd, short events, void *arg) 58 { 59 struct tmuxpeer *peer = arg; 60 ssize_t n; 61 struct imsg imsg; 62 63 if (!(peer->flags & PEER_BAD) && (events & EV_READ)) { 64 if ((n = imsg_read(&peer->ibuf)) == -1 || n == 0) { 65 peer->dispatchcb(NULL, peer->arg); 66 return; 67 } 68 for (;;) { 69 if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) { 70 peer->dispatchcb(NULL, peer->arg); 71 return; 72 } 73 if (n == 0) 74 break; 75 log_debug("peer %p message %d", peer, imsg.hdr.type); 76 77 if (peer_check_version(peer, &imsg) != 0) { 78 if (imsg.fd != -1) 79 close(imsg.fd); 80 imsg_free(&imsg); 81 break; 82 } 83 84 peer->dispatchcb(&imsg, peer->arg); 85 imsg_free(&imsg); 86 } 87 } 88 89 if (events & EV_WRITE) { 90 if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) { 91 peer->dispatchcb(NULL, peer->arg); 92 return; 93 } 94 } 95 96 if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) { 97 peer->dispatchcb(NULL, peer->arg); 98 return; 99 } 100 101 proc_update_event(peer); 102 } 103 104 static void 105 proc_signal_cb(int signo, __unused short events, void *arg) 106 { 107 struct tmuxproc *tp = arg; 108 109 tp->signalcb(signo); 110 } 111 112 static int 113 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg) 114 { 115 int version; 116 117 version = imsg->hdr.peerid & 0xff; 118 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) { 119 log_debug("peer %p bad version %d", peer, version); 120 121 proc_send(peer, MSG_VERSION, -1, NULL, 0); 122 peer->flags |= PEER_BAD; 123 124 return (-1); 125 } 126 return (0); 127 } 128 129 static void 130 proc_update_event(struct tmuxpeer *peer) 131 { 132 short events; 133 134 event_del(&peer->event); 135 136 events = EV_READ; 137 if (peer->ibuf.w.queued > 0) 138 events |= EV_WRITE; 139 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer); 140 141 event_add(&peer->event, NULL); 142 } 143 144 int 145 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf, 146 size_t len) 147 { 148 struct imsgbuf *ibuf = &peer->ibuf; 149 void *vp = (void *)buf; 150 int retval; 151 152 if (peer->flags & PEER_BAD) 153 return (-1); 154 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len); 155 156 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len); 157 if (retval != 1) 158 return (-1); 159 proc_update_event(peer); 160 return (0); 161 } 162 163 int 164 proc_send_s(struct tmuxpeer *peer, enum msgtype type, const char *s) 165 { 166 return (proc_send(peer, type, -1, s, strlen(s) + 1)); 167 } 168 169 struct tmuxproc * 170 proc_start(const char *name, struct event_base *base, int forkflag, 171 void (*signalcb)(int)) 172 { 173 struct tmuxproc *tp; 174 struct utsname u; 175 176 if (forkflag) { 177 switch (fork()) { 178 case -1: 179 fatal("fork failed"); 180 case 0: 181 break; 182 default: 183 return (NULL); 184 } 185 if (daemon(1, 0) != 0) 186 fatal("daemon failed"); 187 188 clear_signals(0); 189 if (event_reinit(base) != 0) 190 fatalx("event_reinit failed"); 191 } 192 193 log_open(name); 194 setproctitle("%s (%s)", name, socket_path); 195 196 if (uname(&u) < 0) 197 memset(&u, 0, sizeof u); 198 199 log_debug("%s started (%ld): socket %s, protocol %d", name, 200 (long)getpid(), socket_path, PROTOCOL_VERSION); 201 log_debug("on %s %s %s; libevent %s (%s)", u.sysname, u.release, 202 u.version, event_get_version(), event_get_method()); 203 204 tp = xcalloc(1, sizeof *tp); 205 tp->name = xstrdup(name); 206 207 tp->signalcb = signalcb; 208 set_signals(proc_signal_cb, tp); 209 210 return (tp); 211 } 212 213 void 214 proc_loop(struct tmuxproc *tp, int (*loopcb)(void)) 215 { 216 log_debug("%s loop enter", tp->name); 217 do 218 event_loop(EVLOOP_ONCE); 219 while (!tp->exit && (loopcb == NULL || !loopcb ())); 220 log_debug("%s loop exit", tp->name); 221 } 222 223 void 224 proc_exit(struct tmuxproc *tp) 225 { 226 tp->exit = 1; 227 } 228 229 struct tmuxpeer * 230 proc_add_peer(struct tmuxproc *tp, int fd, 231 void (*dispatchcb)(struct imsg *, void *), void *arg) 232 { 233 struct tmuxpeer *peer; 234 235 peer = xcalloc(1, sizeof *peer); 236 peer->parent = tp; 237 238 peer->dispatchcb = dispatchcb; 239 peer->arg = arg; 240 241 imsg_init(&peer->ibuf, fd); 242 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer); 243 244 log_debug("add peer %p: %d (%p)", peer, fd, arg); 245 246 proc_update_event(peer); 247 return (peer); 248 } 249 250 void 251 proc_remove_peer(struct tmuxpeer *peer) 252 { 253 log_debug("remove peer %p", peer); 254 255 event_del(&peer->event); 256 imsg_clear(&peer->ibuf); 257 258 close(peer->ibuf.fd); 259 free(peer); 260 } 261 262 void 263 proc_kill_peer(struct tmuxpeer *peer) 264 { 265 peer->flags |= PEER_BAD; 266 } 267