1 /* $OpenBSD: control.c,v 1.17 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 #ifndef SMALL 19 #include <sys/types.h> 20 #include <sys/queue.h> 21 #include <sys/stat.h> 22 #include <sys/socket.h> 23 #include <sys/uio.h> 24 #include <sys/un.h> 25 26 #include <net/if.h> 27 #include <netinet/in.h> 28 #include <netinet/if_ether.h> 29 30 #include <errno.h> 31 #include <event.h> 32 #include <imsg.h> 33 #include <stdlib.h> 34 #include <string.h> 35 #include <unistd.h> 36 37 #include "log.h" 38 #include "slaacd.h" 39 #include "control.h" 40 #include "frontend.h" 41 42 #define CONTROL_BACKLOG 5 43 44 struct { 45 struct event ev; 46 struct event evt; 47 int fd; 48 } control_state = {.fd = -1}; 49 50 struct ctl_conn { 51 TAILQ_ENTRY(ctl_conn) entry; 52 struct imsgev iev; 53 }; 54 55 struct ctl_conn *control_connbyfd(int); 56 struct ctl_conn *control_connbypid(pid_t); 57 void control_close(int); 58 59 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 60 61 int 62 control_init(char *path) 63 { 64 struct sockaddr_un sun; 65 int fd; 66 mode_t old_umask; 67 68 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 69 0)) == -1) { 70 log_warn("%s: socket", __func__); 71 return (-1); 72 } 73 74 memset(&sun, 0, sizeof(sun)); 75 sun.sun_family = AF_UNIX; 76 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 77 78 if (unlink(path) == -1) 79 if (errno != ENOENT) { 80 log_warn("%s: unlink %s", __func__, path); 81 close(fd); 82 return (-1); 83 } 84 85 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 86 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 87 log_warn("%s: bind: %s", __func__, path); 88 close(fd); 89 umask(old_umask); 90 return (-1); 91 } 92 umask(old_umask); 93 94 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 95 log_warn("%s: chmod", __func__); 96 close(fd); 97 (void)unlink(path); 98 return (-1); 99 } 100 101 return (fd); 102 } 103 104 int 105 control_listen(int fd) 106 { 107 if (control_state.fd != -1) 108 fatalx("%s: received unexpected controlsock", __func__); 109 110 control_state.fd = fd; 111 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 112 log_warn("%s: listen", __func__); 113 return (-1); 114 } 115 116 event_set(&control_state.ev, control_state.fd, EV_READ, 117 control_accept, NULL); 118 event_add(&control_state.ev, NULL); 119 evtimer_set(&control_state.evt, control_accept, NULL); 120 121 return (0); 122 } 123 124 void 125 control_accept(int listenfd, short event, void *bula) 126 { 127 int connfd; 128 socklen_t len; 129 struct sockaddr_un sun; 130 struct ctl_conn *c; 131 132 event_add(&control_state.ev, NULL); 133 if ((event & EV_TIMEOUT)) 134 return; 135 136 len = sizeof(sun); 137 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 138 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 139 /* 140 * Pause accept if we are out of file descriptors, or 141 * libevent will haunt us here too. 142 */ 143 if (errno == ENFILE || errno == EMFILE) { 144 struct timeval evtpause = { 1, 0 }; 145 146 event_del(&control_state.ev); 147 evtimer_add(&control_state.evt, &evtpause); 148 } else if (errno != EWOULDBLOCK && errno != EINTR && 149 errno != ECONNABORTED) 150 log_warn("%s: accept4", __func__); 151 return; 152 } 153 154 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 155 log_warn("%s: calloc", __func__); 156 close(connfd); 157 return; 158 } 159 160 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) { 161 log_warn("%s: imsgbuf_init", __func__); 162 close(connfd); 163 free(c); 164 return; 165 } 166 c->iev.handler = control_dispatch_imsg; 167 c->iev.events = EV_READ; 168 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 169 c->iev.handler, &c->iev); 170 event_add(&c->iev.ev, NULL); 171 172 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 173 } 174 175 struct ctl_conn * 176 control_connbyfd(int fd) 177 { 178 struct ctl_conn *c; 179 180 TAILQ_FOREACH(c, &ctl_conns, entry) { 181 if (c->iev.ibuf.fd == fd) 182 break; 183 } 184 185 return (c); 186 } 187 188 struct ctl_conn * 189 control_connbypid(pid_t pid) 190 { 191 struct ctl_conn *c; 192 193 TAILQ_FOREACH(c, &ctl_conns, entry) { 194 if (c->iev.ibuf.pid == pid) 195 break; 196 } 197 198 return (c); 199 } 200 201 void 202 control_close(int fd) 203 { 204 struct ctl_conn *c; 205 206 if ((c = control_connbyfd(fd)) == NULL) { 207 log_warnx("%s: fd %d: not found", __func__, fd); 208 return; 209 } 210 211 imsgbuf_clear(&c->iev.ibuf); 212 TAILQ_REMOVE(&ctl_conns, c, entry); 213 214 event_del(&c->iev.ev); 215 close(c->iev.ibuf.fd); 216 217 /* Some file descriptors are available again. */ 218 if (evtimer_pending(&control_state.evt, NULL)) { 219 evtimer_del(&control_state.evt); 220 event_add(&control_state.ev, NULL); 221 } 222 223 free(c); 224 } 225 226 void 227 control_dispatch_imsg(int fd, short event, void *bula) 228 { 229 struct ctl_conn *c; 230 struct imsg imsg; 231 ssize_t n; 232 int verbose; 233 uint32_t if_index, type; 234 pid_t pid; 235 236 if ((c = control_connbyfd(fd)) == NULL) { 237 log_warnx("%s: fd %d: not found", __func__, fd); 238 return; 239 } 240 241 if (event & EV_READ) { 242 if (imsgbuf_read(&c->iev.ibuf) != 1) { 243 control_close(fd); 244 return; 245 } 246 } 247 if (event & EV_WRITE) { 248 if (imsgbuf_write(&c->iev.ibuf) == -1) { 249 control_close(fd); 250 return; 251 } 252 } 253 254 for (;;) { 255 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 256 control_close(fd); 257 return; 258 } 259 if (n == 0) 260 break; 261 262 type = imsg_get_type(&imsg); 263 pid = imsg_get_pid(&imsg); 264 switch (type) { 265 case IMSG_CTL_LOG_VERBOSE: 266 if (imsg_get_data(&imsg, &verbose, 267 sizeof(verbose)) == -1) 268 break; 269 270 /* Forward to all other processes. */ 271 frontend_imsg_compose_main(type, pid, &verbose, 272 sizeof(verbose)); 273 frontend_imsg_compose_engine(type, 0, pid, &verbose, 274 sizeof(verbose)); 275 276 log_setverbose(verbose); 277 break; 278 case IMSG_CTL_SHOW_INTERFACE_INFO: 279 case IMSG_CTL_SEND_SOLICITATION: 280 if (imsg_get_data(&imsg, &if_index, 281 sizeof(if_index)) == -1) 282 break; 283 284 c->iev.ibuf.pid = pid; 285 frontend_imsg_compose_engine(type, 0, pid, &if_index, 286 sizeof(if_index)); 287 break; 288 default: 289 log_debug("%s: error handling imsg %d", __func__, type); 290 break; 291 } 292 imsg_free(&imsg); 293 } 294 295 imsg_event_add(&c->iev); 296 } 297 298 int 299 control_imsg_relay(struct imsg *imsg) 300 { 301 struct ctl_conn *c; 302 303 if ((c = control_connbypid(imsg_get_pid(imsg))) == NULL) 304 return (0); 305 306 return (imsg_forward_event(&c->iev, imsg)); 307 } 308 #endif /* SMALL */ 309