1 /* $OpenBSD: control.c,v 1.58 2023/03/08 04:43:14 guenther 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 void 131 control_accept(int listenfd, short event, void *arg) 132 { 133 int connfd; 134 socklen_t len; 135 struct sockaddr_un sun; 136 struct ctl_conn *c; 137 struct control_sock *cs = arg; 138 139 event_add(&cs->cs_ev, NULL); 140 if ((event & EV_TIMEOUT)) 141 return; 142 143 len = sizeof(sun); 144 if ((connfd = accept4(listenfd, 145 (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) { 146 /* 147 * Pause accept if we are out of file descriptors, or 148 * libevent will haunt us here too. 149 */ 150 if (errno == ENFILE || errno == EMFILE) { 151 struct timeval evtpause = { 1, 0 }; 152 153 event_del(&cs->cs_ev); 154 evtimer_add(&cs->cs_evt, &evtpause); 155 } else if (errno != EWOULDBLOCK && errno != EINTR && 156 errno != ECONNABORTED) 157 log_warn("%s: accept", __func__); 158 return; 159 } 160 161 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 162 close(connfd); 163 log_warn("%s: calloc", __func__); 164 return; 165 } 166 167 imsg_init(&c->iev.ibuf, connfd); 168 c->iev.handler = control_dispatch_imsg; 169 c->iev.events = EV_READ; 170 c->iev.data = cs; /* proc.c cheats (reuses the handler) */ 171 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 172 c->iev.handler, cs); 173 event_add(&c->iev.ev, NULL); 174 175 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 176 } 177 178 struct ctl_conn * 179 control_connbyfd(int fd) 180 { 181 struct ctl_conn *c; 182 183 TAILQ_FOREACH(c, &ctl_conns, entry) { 184 if (c->iev.ibuf.fd == fd) 185 break; 186 } 187 188 return (c); 189 } 190 191 void 192 control_close(int fd, struct control_sock *cs) 193 { 194 struct ctl_conn *c; 195 196 if ((c = control_connbyfd(fd)) == NULL) { 197 log_warn("%s: fd %d not found", __func__, fd); 198 return; 199 } 200 201 msgbuf_clear(&c->iev.ibuf.w); 202 TAILQ_REMOVE(&ctl_conns, c, entry); 203 204 event_del(&c->iev.ev); 205 close(c->iev.ibuf.fd); 206 207 /* Some file descriptors are available again. */ 208 if (evtimer_pending(&cs->cs_evt, NULL)) { 209 evtimer_del(&cs->cs_evt); 210 event_add(&cs->cs_ev, NULL); 211 } 212 213 free(c); 214 } 215 216 void 217 control_dispatch_imsg(int fd, short event, void *arg) 218 { 219 struct control_sock *cs = arg; 220 struct ctl_conn *c; 221 struct imsg imsg; 222 struct ctl_id id; 223 int n; 224 int verbose; 225 struct relayd *env = cs->cs_env; 226 struct privsep *ps = env->sc_ps; 227 228 if ((c = control_connbyfd(fd)) == NULL) { 229 log_warn("%s: fd %d not found", __func__, fd); 230 return; 231 } 232 233 if (event & EV_READ) { 234 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 235 n == 0) { 236 control_close(fd, cs); 237 return; 238 } 239 } 240 241 if (event & EV_WRITE) { 242 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 243 control_close(fd, cs); 244 return; 245 } 246 } 247 248 for (;;) { 249 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 250 control_close(fd, cs); 251 return; 252 } 253 254 if (n == 0) 255 break; 256 257 if (c->waiting) { 258 log_debug("%s: unexpected imsg %d", 259 __func__, imsg.hdr.type); 260 imsg_free(&imsg); 261 control_close(fd, cs); 262 return; 263 } 264 265 switch (imsg.hdr.type) { 266 case IMSG_CTL_SHOW_SUM: 267 show(c); 268 break; 269 case IMSG_CTL_SESSION: 270 show_sessions(c); 271 break; 272 case IMSG_CTL_RDR_DISABLE: 273 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 274 fatalx("invalid imsg header len"); 275 memcpy(&id, imsg.data, sizeof(id)); 276 if (disable_rdr(c, &id)) 277 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 278 0, ps->ps_instance + 1, -1, NULL, 0); 279 else { 280 memcpy(imsg.data, &id, sizeof(id)); 281 control_imsg_forward(ps, &imsg); 282 imsg_compose_event(&c->iev, IMSG_CTL_OK, 283 0, ps->ps_instance + 1, -1, NULL, 0); 284 } 285 break; 286 case IMSG_CTL_RDR_ENABLE: 287 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 288 fatalx("invalid imsg header len"); 289 memcpy(&id, imsg.data, sizeof(id)); 290 if (enable_rdr(c, &id)) 291 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 292 0, ps->ps_instance + 1, -1, NULL, 0); 293 else { 294 memcpy(imsg.data, &id, sizeof(id)); 295 control_imsg_forward(ps, &imsg); 296 imsg_compose_event(&c->iev, IMSG_CTL_OK, 297 0, ps->ps_instance + 1, -1, NULL, 0); 298 } 299 break; 300 case IMSG_CTL_TABLE_DISABLE: 301 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 302 fatalx("invalid imsg header len"); 303 memcpy(&id, imsg.data, sizeof(id)); 304 if (disable_table(c, &id)) 305 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 306 0, ps->ps_instance + 1, -1, NULL, 0); 307 else { 308 memcpy(imsg.data, &id, sizeof(id)); 309 control_imsg_forward(ps, &imsg); 310 imsg_compose_event(&c->iev, IMSG_CTL_OK, 311 0, ps->ps_instance + 1, -1, NULL, 0); 312 } 313 break; 314 case IMSG_CTL_TABLE_ENABLE: 315 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 316 fatalx("invalid imsg header len"); 317 memcpy(&id, imsg.data, sizeof(id)); 318 if (enable_table(c, &id)) 319 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 320 0, ps->ps_instance + 1, -1, NULL, 0); 321 else { 322 memcpy(imsg.data, &id, sizeof(id)); 323 control_imsg_forward(ps, &imsg); 324 imsg_compose_event(&c->iev, IMSG_CTL_OK, 325 0, ps->ps_instance + 1, -1, NULL, 0); 326 } 327 break; 328 case IMSG_CTL_HOST_DISABLE: 329 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 330 fatalx("invalid imsg header len"); 331 memcpy(&id, imsg.data, sizeof(id)); 332 if (disable_host(c, &id, NULL)) 333 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 334 0, ps->ps_instance + 1, -1, NULL, 0); 335 else { 336 memcpy(imsg.data, &id, sizeof(id)); 337 control_imsg_forward(ps, &imsg); 338 imsg_compose_event(&c->iev, IMSG_CTL_OK, 339 0, ps->ps_instance + 1, -1, NULL, 0); 340 } 341 break; 342 case IMSG_CTL_HOST_ENABLE: 343 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 344 fatalx("invalid imsg header len"); 345 memcpy(&id, imsg.data, sizeof(id)); 346 if (enable_host(c, &id, NULL)) 347 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 348 0, ps->ps_instance + 1, -1, NULL, 0); 349 else { 350 memcpy(imsg.data, &id, sizeof(id)); 351 control_imsg_forward(ps, &imsg); 352 imsg_compose_event(&c->iev, IMSG_CTL_OK, 353 0, ps->ps_instance + 1, -1, NULL, 0); 354 } 355 break; 356 case IMSG_CTL_SHUTDOWN: 357 case IMSG_CTL_RELOAD: 358 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 359 break; 360 case IMSG_CTL_POLL: 361 proc_compose(env->sc_ps, PROC_HCE, 362 IMSG_CTL_POLL, NULL, 0); 363 imsg_compose_event(&c->iev, IMSG_CTL_OK, 364 0, ps->ps_instance + 1, -1, NULL, 0); 365 break; 366 case IMSG_CTL_NOTIFY: 367 if (c->flags & CTL_CONN_NOTIFY) { 368 log_debug("%s: " 369 "client requested notify more than once", 370 __func__); 371 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 372 0, ps->ps_instance + 1, -1, NULL, 0); 373 break; 374 } 375 c->flags |= CTL_CONN_NOTIFY; 376 break; 377 case IMSG_CTL_VERBOSE: 378 IMSG_SIZE_CHECK(&imsg, &verbose); 379 380 memcpy(&verbose, imsg.data, sizeof(verbose)); 381 382 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 383 proc_forward_imsg(env->sc_ps, &imsg, PROC_HCE, -1); 384 proc_forward_imsg(env->sc_ps, &imsg, PROC_RELAY, -1); 385 386 memcpy(imsg.data, &verbose, sizeof(verbose)); 387 control_imsg_forward(ps, &imsg); 388 log_setverbose(verbose); 389 break; 390 default: 391 log_debug("%s: error handling imsg %d", 392 __func__, imsg.hdr.type); 393 break; 394 } 395 imsg_free(&imsg); 396 } 397 398 imsg_event_add(&c->iev); 399 } 400 401 void 402 control_imsg_forward(struct privsep *ps, struct imsg *imsg) 403 { 404 struct ctl_conn *c; 405 406 TAILQ_FOREACH(c, &ctl_conns, entry) 407 if (c->flags & CTL_CONN_NOTIFY) 408 imsg_compose_event(&c->iev, imsg->hdr.type, 409 0, ps->ps_instance + 1, -1, imsg->data, 410 imsg->hdr.len - IMSG_HEADER_SIZE); 411 } 412