1 /* $OpenBSD: control.c,v 1.64 2024/11/21 13:38:45 claudio 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 log_warn("%s: calloc", __func__); 163 close(connfd); 164 return; 165 } 166 167 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) { 168 log_warn("%s: imsgbuf_init", __func__); 169 close(connfd); 170 free(c); 171 return; 172 } 173 174 c->iev.handler = control_dispatch_imsg; 175 c->iev.events = EV_READ; 176 c->iev.data = cs; /* proc.c cheats (reuses the handler) */ 177 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 178 c->iev.handler, cs); 179 event_add(&c->iev.ev, NULL); 180 181 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 182 } 183 184 struct ctl_conn * 185 control_connbyfd(int fd) 186 { 187 struct ctl_conn *c; 188 189 TAILQ_FOREACH(c, &ctl_conns, entry) { 190 if (c->iev.ibuf.fd == fd) 191 break; 192 } 193 194 return (c); 195 } 196 197 void 198 control_close(int fd, struct control_sock *cs) 199 { 200 struct ctl_conn *c; 201 202 if ((c = control_connbyfd(fd)) == NULL) { 203 log_warn("%s: fd %d not found", __func__, fd); 204 return; 205 } 206 207 imsgbuf_clear(&c->iev.ibuf); 208 TAILQ_REMOVE(&ctl_conns, c, entry); 209 210 event_del(&c->iev.ev); 211 close(c->iev.ibuf.fd); 212 213 /* Some file descriptors are available again. */ 214 if (evtimer_pending(&cs->cs_evt, NULL)) { 215 evtimer_del(&cs->cs_evt); 216 event_add(&cs->cs_ev, NULL); 217 } 218 219 free(c); 220 } 221 222 void 223 control_dispatch_imsg(int fd, short event, void *arg) 224 { 225 struct control_sock *cs = arg; 226 struct ctl_conn *c; 227 struct imsg imsg; 228 struct ctl_id id; 229 int n; 230 int verbose; 231 struct relayd *env = cs->cs_env; 232 struct privsep *ps = env->sc_ps; 233 234 if ((c = control_connbyfd(fd)) == NULL) { 235 log_warn("%s: fd %d not found", __func__, fd); 236 return; 237 } 238 239 if (event & EV_READ) { 240 if (imsgbuf_read(&c->iev.ibuf) != 1) { 241 control_close(fd, cs); 242 return; 243 } 244 } 245 246 if (event & EV_WRITE) { 247 if (imsgbuf_write(&c->iev.ibuf) == -1) { 248 control_close(fd, cs); 249 return; 250 } 251 } 252 253 for (;;) { 254 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 255 control_close(fd, cs); 256 return; 257 } 258 259 if (n == 0) 260 break; 261 262 if (c->waiting) { 263 log_debug("%s: unexpected imsg %d", 264 __func__, imsg.hdr.type); 265 imsg_free(&imsg); 266 control_close(fd, cs); 267 return; 268 } 269 270 switch (imsg.hdr.type) { 271 case IMSG_CTL_SHOW_SUM: 272 show(c); 273 break; 274 case IMSG_CTL_SESSION: 275 show_sessions(c); 276 break; 277 case IMSG_CTL_RDR_DISABLE: 278 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 279 fatalx("invalid imsg header len"); 280 memcpy(&id, imsg.data, sizeof(id)); 281 if (disable_rdr(c, &id)) 282 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 283 0, ps->ps_instance + 1, -1, NULL, 0); 284 else { 285 memcpy(imsg.data, &id, sizeof(id)); 286 control_imsg_forward(ps, &imsg); 287 imsg_compose_event(&c->iev, IMSG_CTL_OK, 288 0, ps->ps_instance + 1, -1, NULL, 0); 289 } 290 break; 291 case IMSG_CTL_RDR_ENABLE: 292 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 293 fatalx("invalid imsg header len"); 294 memcpy(&id, imsg.data, sizeof(id)); 295 if (enable_rdr(c, &id)) 296 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 297 0, ps->ps_instance + 1, -1, NULL, 0); 298 else { 299 memcpy(imsg.data, &id, sizeof(id)); 300 control_imsg_forward(ps, &imsg); 301 imsg_compose_event(&c->iev, IMSG_CTL_OK, 302 0, ps->ps_instance + 1, -1, NULL, 0); 303 } 304 break; 305 case IMSG_CTL_TABLE_DISABLE: 306 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 307 fatalx("invalid imsg header len"); 308 memcpy(&id, imsg.data, sizeof(id)); 309 if (disable_table(c, &id)) 310 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 311 0, ps->ps_instance + 1, -1, NULL, 0); 312 else { 313 memcpy(imsg.data, &id, sizeof(id)); 314 control_imsg_forward(ps, &imsg); 315 imsg_compose_event(&c->iev, IMSG_CTL_OK, 316 0, ps->ps_instance + 1, -1, NULL, 0); 317 } 318 break; 319 case IMSG_CTL_TABLE_ENABLE: 320 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 321 fatalx("invalid imsg header len"); 322 memcpy(&id, imsg.data, sizeof(id)); 323 if (enable_table(c, &id)) 324 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 325 0, ps->ps_instance + 1, -1, NULL, 0); 326 else { 327 memcpy(imsg.data, &id, sizeof(id)); 328 control_imsg_forward(ps, &imsg); 329 imsg_compose_event(&c->iev, IMSG_CTL_OK, 330 0, ps->ps_instance + 1, -1, NULL, 0); 331 } 332 break; 333 case IMSG_CTL_HOST_DISABLE: 334 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 335 fatalx("invalid imsg header len"); 336 memcpy(&id, imsg.data, sizeof(id)); 337 if (disable_host(c, &id, NULL)) 338 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 339 0, ps->ps_instance + 1, -1, NULL, 0); 340 else { 341 memcpy(imsg.data, &id, sizeof(id)); 342 control_imsg_forward(ps, &imsg); 343 imsg_compose_event(&c->iev, IMSG_CTL_OK, 344 0, ps->ps_instance + 1, -1, NULL, 0); 345 } 346 break; 347 case IMSG_CTL_HOST_ENABLE: 348 if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(id)) 349 fatalx("invalid imsg header len"); 350 memcpy(&id, imsg.data, sizeof(id)); 351 if (enable_host(c, &id, NULL)) 352 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 353 0, ps->ps_instance + 1, -1, NULL, 0); 354 else { 355 memcpy(imsg.data, &id, sizeof(id)); 356 control_imsg_forward(ps, &imsg); 357 imsg_compose_event(&c->iev, IMSG_CTL_OK, 358 0, ps->ps_instance + 1, -1, NULL, 0); 359 } 360 break; 361 case IMSG_CTL_SHUTDOWN: 362 case IMSG_CTL_RELOAD: 363 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 364 break; 365 case IMSG_CTL_POLL: 366 proc_compose(env->sc_ps, PROC_HCE, 367 IMSG_CTL_POLL, NULL, 0); 368 imsg_compose_event(&c->iev, IMSG_CTL_OK, 369 0, ps->ps_instance + 1, -1, NULL, 0); 370 break; 371 case IMSG_CTL_NOTIFY: 372 if (c->flags & CTL_CONN_NOTIFY) { 373 log_debug("%s: " 374 "client requested notify more than once", 375 __func__); 376 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 377 0, ps->ps_instance + 1, -1, NULL, 0); 378 break; 379 } 380 c->flags |= CTL_CONN_NOTIFY; 381 break; 382 case IMSG_CTL_VERBOSE: 383 IMSG_SIZE_CHECK(&imsg, &verbose); 384 385 memcpy(&verbose, imsg.data, sizeof(verbose)); 386 387 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 388 proc_forward_imsg(env->sc_ps, &imsg, PROC_HCE, -1); 389 proc_forward_imsg(env->sc_ps, &imsg, PROC_RELAY, -1); 390 391 memcpy(imsg.data, &verbose, sizeof(verbose)); 392 control_imsg_forward(ps, &imsg); 393 log_setverbose(verbose); 394 break; 395 default: 396 log_debug("%s: error handling imsg %d", 397 __func__, imsg.hdr.type); 398 break; 399 } 400 imsg_free(&imsg); 401 } 402 403 imsg_event_add(&c->iev); 404 } 405 406 void 407 control_imsg_forward(struct privsep *ps, struct imsg *imsg) 408 { 409 struct ctl_conn *c; 410 411 TAILQ_FOREACH(c, &ctl_conns, entry) 412 if (c->flags & CTL_CONN_NOTIFY) 413 imsg_compose_event(&c->iev, imsg->hdr.type, 414 0, ps->ps_instance + 1, -1, imsg->data, 415 imsg->hdr.len - IMSG_HEADER_SIZE); 416 } 417