1 /* $OpenBSD: proc.c,v 1.5 2015/11/24 21:19:46 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 23 #include <errno.h> 24 #include <event.h> 25 #include <imsg.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <unistd.h> 29 30 #include "tmux.h" 31 32 struct tmuxproc { 33 const char *name; 34 int exit; 35 36 void (*signalcb)(int); 37 }; 38 39 struct tmuxpeer { 40 struct tmuxproc *parent; 41 42 struct imsgbuf ibuf; 43 struct event event; 44 45 int flags; 46 #define PEER_BAD 0x1 47 48 void (*dispatchcb)(struct imsg *, void *); 49 void *arg; 50 }; 51 52 static int peer_check_version(struct tmuxpeer *, struct imsg *); 53 static void proc_update_event(struct tmuxpeer *); 54 55 static void 56 proc_event_cb(__unused int fd, short events, void *arg) 57 { 58 struct tmuxpeer *peer = arg; 59 ssize_t n; 60 struct imsg imsg; 61 62 if (!(peer->flags & PEER_BAD) && (events & EV_READ)) { 63 if ((n = imsg_read(&peer->ibuf)) == -1 || n == 0) { 64 peer->dispatchcb(NULL, peer->arg); 65 return; 66 } 67 for (;;) { 68 if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) { 69 peer->dispatchcb(NULL, peer->arg); 70 return; 71 } 72 if (n == 0) 73 break; 74 log_debug("peer %p message %d", peer, imsg.hdr.type); 75 76 if (peer_check_version(peer, &imsg) != 0) { 77 if (imsg.fd != -1) 78 close(imsg.fd); 79 imsg_free(&imsg); 80 break; 81 } 82 83 peer->dispatchcb(&imsg, peer->arg); 84 imsg_free(&imsg); 85 } 86 } 87 88 if (events & EV_WRITE) { 89 if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) { 90 peer->dispatchcb(NULL, peer->arg); 91 return; 92 } 93 } 94 95 if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) { 96 peer->dispatchcb(NULL, peer->arg); 97 return; 98 } 99 100 proc_update_event(peer); 101 } 102 103 static void 104 proc_signal_cb(int signo, __unused short events, void *arg) 105 { 106 struct tmuxproc *tp = arg; 107 108 tp->signalcb(signo); 109 } 110 111 static int 112 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg) 113 { 114 int version; 115 116 version = imsg->hdr.peerid & 0xff; 117 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) { 118 log_debug("peer %p bad version %d", peer, version); 119 120 proc_send(peer, MSG_VERSION, -1, NULL, 0); 121 peer->flags |= PEER_BAD; 122 123 return (-1); 124 } 125 return (0); 126 } 127 128 static void 129 proc_update_event(struct tmuxpeer *peer) 130 { 131 short events; 132 133 event_del(&peer->event); 134 135 events = EV_READ; 136 if (peer->ibuf.w.queued > 0) 137 events |= EV_WRITE; 138 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer); 139 140 event_add(&peer->event, NULL); 141 } 142 143 int 144 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf, 145 size_t len) 146 { 147 struct imsgbuf *ibuf = &peer->ibuf; 148 void *vp = (void *)buf; 149 int retval; 150 151 if (peer->flags & PEER_BAD) 152 return (-1); 153 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len); 154 155 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len); 156 if (retval != 1) 157 return (-1); 158 proc_update_event(peer); 159 return (0); 160 } 161 162 int 163 proc_send_s(struct tmuxpeer *peer, enum msgtype type, const char *s) 164 { 165 return (proc_send(peer, type, -1, s, strlen(s) + 1)); 166 } 167 168 struct tmuxproc * 169 proc_start(const char *name, struct event_base *base, int forkflag, 170 void (*signalcb)(int)) 171 { 172 struct tmuxproc *tp; 173 174 if (forkflag) { 175 switch (fork()) { 176 case -1: 177 fatal("fork failed"); 178 case 0: 179 break; 180 default: 181 return (NULL); 182 } 183 if (daemon(1, 0) != 0) 184 fatal("daemon failed"); 185 186 clear_signals(0); 187 if (event_reinit(base) != 0) 188 fatalx("event_reinit failed"); 189 } 190 191 log_open(name); 192 setproctitle("%s (%s)", name, socket_path); 193 194 log_debug("%s started (%ld): socket %s, protocol %d", name, 195 (long)getpid(), socket_path, PROTOCOL_VERSION); 196 197 tp = xcalloc(1, sizeof *tp); 198 tp->name = xstrdup(name); 199 200 tp->signalcb = signalcb; 201 set_signals(proc_signal_cb, tp); 202 203 return (tp); 204 } 205 206 void 207 proc_loop(struct tmuxproc *tp, int (*loopcb)(void)) 208 { 209 log_debug("%s loop enter", tp->name); 210 do 211 event_loop(EVLOOP_ONCE); 212 while (!tp->exit && (loopcb == NULL || !loopcb ())); 213 log_debug("%s loop exit", tp->name); 214 } 215 216 void 217 proc_exit(struct tmuxproc *tp) 218 { 219 tp->exit = 1; 220 } 221 222 struct tmuxpeer * 223 proc_add_peer(struct tmuxproc *tp, int fd, 224 void (*dispatchcb)(struct imsg *, void *), void *arg) 225 { 226 struct tmuxpeer *peer; 227 228 peer = xcalloc(1, sizeof *peer); 229 peer->parent = tp; 230 231 peer->dispatchcb = dispatchcb; 232 peer->arg = arg; 233 234 imsg_init(&peer->ibuf, fd); 235 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer); 236 237 log_debug("add peer %p: %d (%p)", peer, fd, arg); 238 239 proc_update_event(peer); 240 return (peer); 241 } 242 243 void 244 proc_remove_peer(struct tmuxpeer *peer) 245 { 246 log_debug("remove peer %p", peer); 247 248 event_del(&peer->event); 249 imsg_clear(&peer->ibuf); 250 251 close(peer->ibuf.fd); 252 free(peer); 253 } 254 255 void 256 proc_kill_peer(struct tmuxpeer *peer) 257 { 258 peer->flags |= PEER_BAD; 259 } 260