1 /* $OpenBSD: control.c,v 1.12 2024/11/21 13:35:20 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 #include <sys/types.h> 19 #include <sys/queue.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/uio.h> 23 #include <sys/un.h> 24 25 #include <net/if.h> 26 #include <netinet/in.h> 27 #include <netinet/if_ether.h> 28 29 #include <errno.h> 30 #include <event.h> 31 #include <imsg.h> 32 #include <stdlib.h> 33 #include <string.h> 34 #include <unistd.h> 35 36 #include "log.h" 37 #include "dhcpleased.h" 38 #include "control.h" 39 #include "frontend.h" 40 41 #define CONTROL_BACKLOG 5 42 43 struct { 44 struct event ev; 45 struct event evt; 46 int fd; 47 } control_state = {.fd = -1}; 48 49 struct ctl_conn { 50 TAILQ_ENTRY(ctl_conn) entry; 51 struct imsgev iev; 52 }; 53 54 struct ctl_conn *control_connbyfd(int); 55 struct ctl_conn *control_connbypid(pid_t); 56 void control_close(int); 57 58 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 59 60 int 61 control_init(char *path) 62 { 63 struct sockaddr_un sun; 64 int fd; 65 mode_t old_umask; 66 67 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 68 0)) == -1) { 69 log_warn("%s: socket", __func__); 70 return (-1); 71 } 72 73 memset(&sun, 0, sizeof(sun)); 74 sun.sun_family = AF_UNIX; 75 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 76 77 if (unlink(path) == -1) 78 if (errno != ENOENT) { 79 log_warn("%s: unlink %s", __func__, path); 80 close(fd); 81 return (-1); 82 } 83 84 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 85 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 86 log_warn("%s: bind: %s", __func__, path); 87 close(fd); 88 umask(old_umask); 89 return (-1); 90 } 91 umask(old_umask); 92 93 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 94 log_warn("%s: chmod", __func__); 95 close(fd); 96 (void)unlink(path); 97 return (-1); 98 } 99 100 return (fd); 101 } 102 103 int 104 control_listen(int fd) 105 { 106 if (control_state.fd != -1) 107 fatalx("%s: received unexpected controlsock", __func__); 108 109 control_state.fd = fd; 110 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 111 log_warn("%s: listen", __func__); 112 return (-1); 113 } 114 115 event_set(&control_state.ev, control_state.fd, EV_READ, 116 control_accept, NULL); 117 event_add(&control_state.ev, NULL); 118 evtimer_set(&control_state.evt, control_accept, NULL); 119 120 return (0); 121 } 122 123 void 124 control_accept(int listenfd, short event, void *bula) 125 { 126 int connfd; 127 socklen_t len; 128 struct sockaddr_un sun; 129 struct ctl_conn *c; 130 131 event_add(&control_state.ev, NULL); 132 if ((event & EV_TIMEOUT)) 133 return; 134 135 len = sizeof(sun); 136 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 137 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 138 /* 139 * Pause accept if we are out of file descriptors, or 140 * libevent will haunt us here too. 141 */ 142 if (errno == ENFILE || errno == EMFILE) { 143 struct timeval evtpause = { 1, 0 }; 144 145 event_del(&control_state.ev); 146 evtimer_add(&control_state.evt, &evtpause); 147 } else if (errno != EWOULDBLOCK && errno != EINTR && 148 errno != ECONNABORTED) 149 log_warn("%s: accept4", __func__); 150 return; 151 } 152 153 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 154 log_warn("%s: calloc", __func__); 155 close(connfd); 156 return; 157 } 158 159 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) { 160 log_warn("%s: imsgbuf_init", __func__); 161 close(connfd); 162 free(c); 163 return; 164 } 165 c->iev.handler = control_dispatch_imsg; 166 c->iev.events = EV_READ; 167 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 168 c->iev.handler, &c->iev); 169 event_add(&c->iev.ev, NULL); 170 171 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 172 } 173 174 struct ctl_conn * 175 control_connbyfd(int fd) 176 { 177 struct ctl_conn *c; 178 179 TAILQ_FOREACH(c, &ctl_conns, entry) { 180 if (c->iev.ibuf.fd == fd) 181 break; 182 } 183 184 return (c); 185 } 186 187 struct ctl_conn * 188 control_connbypid(pid_t pid) 189 { 190 struct ctl_conn *c; 191 192 TAILQ_FOREACH(c, &ctl_conns, entry) { 193 if (c->iev.ibuf.pid == pid) 194 break; 195 } 196 197 return (c); 198 } 199 200 void 201 control_close(int fd) 202 { 203 struct ctl_conn *c; 204 205 if ((c = control_connbyfd(fd)) == NULL) { 206 log_warnx("%s: fd %d: not found", __func__, fd); 207 return; 208 } 209 210 imsgbuf_clear(&c->iev.ibuf); 211 TAILQ_REMOVE(&ctl_conns, c, entry); 212 213 event_del(&c->iev.ev); 214 close(c->iev.ibuf.fd); 215 216 /* Some file descriptors are available again. */ 217 if (evtimer_pending(&control_state.evt, NULL)) { 218 evtimer_del(&control_state.evt); 219 event_add(&control_state.ev, NULL); 220 } 221 222 free(c); 223 } 224 225 void 226 control_dispatch_imsg(int fd, short event, void *bula) 227 { 228 struct ctl_conn *c; 229 struct imsg imsg; 230 ssize_t n; 231 int verbose; 232 uint32_t if_index, type; 233 pid_t pid; 234 235 if ((c = control_connbyfd(fd)) == NULL) { 236 log_warnx("%s: fd %d: not found", __func__, fd); 237 return; 238 } 239 240 if (event & EV_READ) { 241 if (imsgbuf_read(&c->iev.ibuf) != 1) { 242 control_close(fd); 243 return; 244 } 245 } 246 if (event & EV_WRITE) { 247 if (imsgbuf_write(&c->iev.ibuf) == -1) { 248 control_close(fd); 249 return; 250 } 251 } 252 253 for (;;) { 254 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 255 control_close(fd); 256 return; 257 } 258 if (n == 0) 259 break; 260 261 type = imsg_get_type(&imsg); 262 pid = imsg_get_pid(&imsg); 263 264 switch (type) { 265 case IMSG_CTL_RELOAD: 266 frontend_imsg_compose_main(type, 0, NULL, 0); 267 break; 268 case IMSG_CTL_LOG_VERBOSE: 269 if (imsg_get_data(&imsg, &verbose, 270 sizeof(verbose)) == -1) 271 break; 272 273 c->iev.ibuf.pid = pid; 274 /* Forward to all other processes. */ 275 frontend_imsg_compose_main(type, pid, &verbose, 276 sizeof(verbose)); 277 frontend_imsg_compose_engine(type, 0, pid, &verbose, 278 sizeof(verbose)); 279 280 log_setverbose(verbose); 281 break; 282 case IMSG_CTL_SHOW_INTERFACE_INFO: 283 if (imsg_get_data(&imsg, &if_index, 284 sizeof(if_index)) == -1) 285 break; 286 287 c->iev.ibuf.pid = pid; 288 frontend_imsg_compose_engine(type, 0, pid, &if_index, 289 sizeof(if_index)); 290 break; 291 case IMSG_CTL_SEND_REQUEST: 292 if (imsg_get_data(&imsg, &if_index, 293 sizeof(if_index)) == -1) 294 break; 295 296 c->iev.ibuf.pid = pid; 297 frontend_imsg_compose_engine(IMSG_REQUEST_REBOOT, 0, 298 pid, &if_index, sizeof(if_index)); 299 break; 300 default: 301 log_debug("%s: error handling imsg %d", __func__, type); 302 break; 303 } 304 imsg_free(&imsg); 305 } 306 307 imsg_event_add(&c->iev); 308 } 309 310 int 311 control_imsg_relay(struct imsg *imsg) 312 { 313 struct ctl_conn *c; 314 315 if ((c = control_connbypid(imsg_get_pid(imsg))) == NULL) 316 return (0); 317 318 return (imsg_forward_event(&c->iev, imsg)); 319 } 320