1 /* $OpenBSD: control.c,v 1.57 2021/04/20 21:11:56 dv Exp $ */ 2 3 /* 4 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org> 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 USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/queue.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/time.h> 23 #include <sys/un.h> 24 25 #include <errno.h> 26 #include <event.h> 27 #include <fcntl.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #include <unistd.h> 31 #include <imsg.h> 32 33 #include "relayd.h" 34 35 #define CONTROL_BACKLOG 5 36 37 struct ctl_connlist ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 38 39 void control_accept(int, short, void *); 40 void control_close(int, struct control_sock *); 41 42 int 43 control_init(struct privsep *ps, struct control_sock *cs) 44 { 45 struct relayd *env = ps->ps_env; 46 struct sockaddr_un sun; 47 int fd; 48 mode_t old_umask, mode; 49 50 if (cs->cs_name == NULL) 51 return (0); 52 53 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) { 54 log_warn("%s: socket", __func__); 55 return (-1); 56 } 57 58 sun.sun_family = AF_UNIX; 59 if (strlcpy(sun.sun_path, cs->cs_name, 60 sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) { 61 log_warn("%s: %s name too long", __func__, cs->cs_name); 62 close(fd); 63 return (-1); 64 } 65 66 if (unlink(cs->cs_name) == -1) 67 if (errno != ENOENT) { 68 log_warn("%s: unlink %s", __func__, cs->cs_name); 69 close(fd); 70 return (-1); 71 } 72 73 if (cs->cs_restricted) { 74 old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH); 75 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH; 76 } else { 77 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 78 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP; 79 } 80 81 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 82 log_warn("%s: bind: %s", __func__, cs->cs_name); 83 close(fd); 84 (void)umask(old_umask); 85 return (-1); 86 } 87 (void)umask(old_umask); 88 89 if (chmod(cs->cs_name, mode) == -1) { 90 log_warn("%s: chmod", __func__); 91 close(fd); 92 (void)unlink(cs->cs_name); 93 return (-1); 94 } 95 96 cs->cs_fd = fd; 97 cs->cs_env = env; 98 99 return (0); 100 } 101 102 int 103 control_listen(struct control_sock *cs) 104 { 105 if (cs->cs_name == NULL) 106 return (0); 107 108 if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) { 109 log_warn("%s: listen", __func__); 110 return (-1); 111 } 112 113 event_set(&cs->cs_ev, cs->cs_fd, EV_READ, 114 control_accept, cs); 115 event_add(&cs->cs_ev, NULL); 116 evtimer_set(&cs->cs_evt, control_accept, cs); 117 118 return (0); 119 } 120 121 void 122 control_cleanup(struct control_sock *cs) 123 { 124 if (cs->cs_name == NULL) 125 return; 126 event_del(&cs->cs_ev); 127 event_del(&cs->cs_evt); 128 } 129 130 /* ARGSUSED */ 131 void 132 control_accept(int listenfd, short event, void *arg) 133 { 134 int connfd; 135 socklen_t len; 136 struct sockaddr_un sun; 137 struct ctl_conn *c; 138 struct control_sock *cs = arg; 139 140 event_add(&cs->cs_ev, NULL); 141 if ((event & EV_TIMEOUT)) 142 return; 143 144 len = sizeof(sun); 145 if ((connfd = accept4(listenfd, 146 (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) { 147 /* 148 * Pause accept if we are out of file descriptors, or 149 * libevent will haunt us here too. 150 */ 151 if (errno == ENFILE || errno == EMFILE) { 152 struct timeval evtpause = { 1, 0 }; 153 154 event_del(&cs->cs_ev); 155 evtimer_add(&cs->cs_evt, &evtpause); 156 } else if (errno != EWOULDBLOCK && errno != EINTR && 157 errno != ECONNABORTED) 158 log_warn("%s: accept", __func__); 159 return; 160 } 161 162 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 163 close(connfd); 164 log_warn("%s: calloc", __func__); 165 return; 166 } 167 168 imsg_init(&c->iev.ibuf, connfd); 169 c->iev.handler = control_dispatch_imsg; 170 c->iev.events = EV_READ; 171 c->iev.data = cs; /* proc.c cheats (reuses the handler) */ 172 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 173 c->iev.handler, cs); 174 event_add(&c->iev.ev, NULL); 175 176 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 177 } 178 179 struct ctl_conn * 180 control_connbyfd(int fd) 181 { 182 struct ctl_conn *c; 183 184 TAILQ_FOREACH(c, &ctl_conns, entry) { 185 if (c->iev.ibuf.fd == fd) 186 break; 187 } 188 189 return (c); 190 } 191 192 void 193 control_close(int fd, struct control_sock *cs) 194 { 195 struct ctl_conn *c; 196 197 if ((c = control_connbyfd(fd)) == NULL) { 198 log_warn("%s: fd %d not found", __func__, fd); 199 return; 200 } 201 202 msgbuf_clear(&c->iev.ibuf.w); 203 TAILQ_REMOVE(&ctl_conns, c, entry); 204 205 event_del(&c->iev.ev); 206 close(c->iev.ibuf.fd); 207 208 /* Some file descriptors are available again. */ 209 if (evtimer_pending(&cs->cs_evt, NULL)) { 210 evtimer_del(&cs->cs_evt); 211 event_add(&cs->cs_ev, NULL); 212 } 213 214 free(c); 215 } 216 217 /* ARGSUSED */ 218 void 219 control_dispatch_imsg(int fd, short event, void *arg) 220 { 221 struct control_sock *cs = arg; 222 struct ctl_conn *c; 223 struct imsg imsg; 224 struct ctl_id id; 225 int n; 226 int verbose; 227 struct relayd *env = cs->cs_env; 228 struct privsep *ps = env->sc_ps; 229 230 if ((c = control_connbyfd(fd)) == NULL) { 231 log_warn("%s: fd %d not found", __func__, fd); 232 return; 233 } 234 235 if (event & EV_READ) { 236 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 237 n == 0) { 238 control_close(fd, cs); 239 return; 240 } 241 } 242 243 if (event & EV_WRITE) { 244 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 245 control_close(fd, cs); 246 return; 247 } 248 } 249 250 for (;;) { 251 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 252 control_close(fd, cs); 253 return; 254 } 255 256 if (n == 0) 257 break; 258 259 if (c->waiting) { 260 log_debug("%s: unexpected imsg %d", 261 __func__, imsg.hdr.type); 262 imsg_free(&imsg); 263 control_close(fd, cs); 264 return; 265 } 266 267 switch (imsg.hdr.type) { 268 case IMSG_CTL_SHOW_SUM: 269 show(c); 270 break; 271 case IMSG_CTL_SESSION: 272 show_sessions(c); 273 break; 274 case IMSG_CTL_RDR_DISABLE: 275 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 276 fatalx("invalid imsg header len"); 277 memcpy(&id, imsg.data, sizeof(id)); 278 if (disable_rdr(c, &id)) 279 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 280 0, ps->ps_instance + 1, -1, NULL, 0); 281 else { 282 memcpy(imsg.data, &id, sizeof(id)); 283 control_imsg_forward(ps, &imsg); 284 imsg_compose_event(&c->iev, IMSG_CTL_OK, 285 0, ps->ps_instance + 1, -1, NULL, 0); 286 } 287 break; 288 case IMSG_CTL_RDR_ENABLE: 289 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 290 fatalx("invalid imsg header len"); 291 memcpy(&id, imsg.data, sizeof(id)); 292 if (enable_rdr(c, &id)) 293 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 294 0, ps->ps_instance + 1, -1, NULL, 0); 295 else { 296 memcpy(imsg.data, &id, sizeof(id)); 297 control_imsg_forward(ps, &imsg); 298 imsg_compose_event(&c->iev, IMSG_CTL_OK, 299 0, ps->ps_instance + 1, -1, NULL, 0); 300 } 301 break; 302 case IMSG_CTL_TABLE_DISABLE: 303 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 304 fatalx("invalid imsg header len"); 305 memcpy(&id, imsg.data, sizeof(id)); 306 if (disable_table(c, &id)) 307 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 308 0, ps->ps_instance + 1, -1, NULL, 0); 309 else { 310 memcpy(imsg.data, &id, sizeof(id)); 311 control_imsg_forward(ps, &imsg); 312 imsg_compose_event(&c->iev, IMSG_CTL_OK, 313 0, ps->ps_instance + 1, -1, NULL, 0); 314 } 315 break; 316 case IMSG_CTL_TABLE_ENABLE: 317 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 318 fatalx("invalid imsg header len"); 319 memcpy(&id, imsg.data, sizeof(id)); 320 if (enable_table(c, &id)) 321 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 322 0, ps->ps_instance + 1, -1, NULL, 0); 323 else { 324 memcpy(imsg.data, &id, sizeof(id)); 325 control_imsg_forward(ps, &imsg); 326 imsg_compose_event(&c->iev, IMSG_CTL_OK, 327 0, ps->ps_instance + 1, -1, NULL, 0); 328 } 329 break; 330 case IMSG_CTL_HOST_DISABLE: 331 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 332 fatalx("invalid imsg header len"); 333 memcpy(&id, imsg.data, sizeof(id)); 334 if (disable_host(c, &id, NULL)) 335 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 336 0, ps->ps_instance + 1, -1, NULL, 0); 337 else { 338 memcpy(imsg.data, &id, sizeof(id)); 339 control_imsg_forward(ps, &imsg); 340 imsg_compose_event(&c->iev, IMSG_CTL_OK, 341 0, ps->ps_instance + 1, -1, NULL, 0); 342 } 343 break; 344 case IMSG_CTL_HOST_ENABLE: 345 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 346 fatalx("invalid imsg header len"); 347 memcpy(&id, imsg.data, sizeof(id)); 348 if (enable_host(c, &id, NULL)) 349 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 350 0, ps->ps_instance + 1, -1, NULL, 0); 351 else { 352 memcpy(imsg.data, &id, sizeof(id)); 353 control_imsg_forward(ps, &imsg); 354 imsg_compose_event(&c->iev, IMSG_CTL_OK, 355 0, ps->ps_instance + 1, -1, NULL, 0); 356 } 357 break; 358 case IMSG_CTL_SHUTDOWN: 359 case IMSG_CTL_RELOAD: 360 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 361 break; 362 case IMSG_CTL_POLL: 363 proc_compose(env->sc_ps, PROC_HCE, 364 IMSG_CTL_POLL, NULL, 0); 365 imsg_compose_event(&c->iev, IMSG_CTL_OK, 366 0, ps->ps_instance + 1, -1, NULL, 0); 367 break; 368 case IMSG_CTL_NOTIFY: 369 if (c->flags & CTL_CONN_NOTIFY) { 370 log_debug("%s: " 371 "client requested notify more than once", 372 __func__); 373 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 374 0, ps->ps_instance + 1, -1, NULL, 0); 375 break; 376 } 377 c->flags |= CTL_CONN_NOTIFY; 378 break; 379 case IMSG_CTL_VERBOSE: 380 IMSG_SIZE_CHECK(&imsg, &verbose); 381 382 memcpy(&verbose, imsg.data, sizeof(verbose)); 383 384 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 385 proc_forward_imsg(env->sc_ps, &imsg, PROC_HCE, -1); 386 proc_forward_imsg(env->sc_ps, &imsg, PROC_RELAY, -1); 387 388 memcpy(imsg.data, &verbose, sizeof(verbose)); 389 control_imsg_forward(ps, &imsg); 390 log_setverbose(verbose); 391 break; 392 default: 393 log_debug("%s: error handling imsg %d", 394 __func__, imsg.hdr.type); 395 break; 396 } 397 imsg_free(&imsg); 398 } 399 400 imsg_event_add(&c->iev); 401 } 402 403 void 404 control_imsg_forward(struct privsep *ps, struct imsg *imsg) 405 { 406 struct ctl_conn *c; 407 408 TAILQ_FOREACH(c, &ctl_conns, entry) 409 if (c->flags & CTL_CONN_NOTIFY) 410 imsg_compose_event(&c->iev, imsg->hdr.type, 411 0, ps->ps_instance + 1, -1, imsg->data, 412 imsg->hdr.len - IMSG_HEADER_SIZE); 413 } 414