1 /* $OpenBSD: control.c,v 1.10 2023/03/08 04:43:13 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/types.h> 20 #include <sys/stat.h> 21 #include <sys/un.h> 22 23 #include <errno.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <unistd.h> 27 28 #include "eigrpd.h" 29 #include "eigrpe.h" 30 #include "control.h" 31 #include "log.h" 32 33 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 34 35 #define CONTROL_BACKLOG 5 36 37 static void control_accept(int, short, void *); 38 static struct ctl_conn *control_connbyfd(int); 39 static struct ctl_conn *control_connbypid(pid_t); 40 static void control_close(int); 41 static void control_dispatch_imsg(int, short, void *); 42 43 struct { 44 struct event ev; 45 struct event evt; 46 int fd; 47 } control_state; 48 49 50 int 51 control_init(char *path) 52 { 53 struct sockaddr_un sun; 54 int fd; 55 mode_t old_umask; 56 57 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 58 0)) == -1) { 59 log_warn("%s: socket", __func__); 60 return (-1); 61 } 62 63 memset(&sun, 0, sizeof(sun)); 64 sun.sun_family = AF_UNIX; 65 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 66 67 if (unlink(path) == -1) 68 if (errno != ENOENT) { 69 log_warn("%s: unlink %s", __func__, path); 70 close(fd); 71 return (-1); 72 } 73 74 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 75 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 76 log_warn("%s: bind: %s", __func__, path); 77 close(fd); 78 umask(old_umask); 79 return (-1); 80 } 81 umask(old_umask); 82 83 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 84 log_warn("%s: chmod", __func__); 85 close(fd); 86 (void)unlink(path); 87 return (-1); 88 } 89 90 control_state.fd = fd; 91 92 return (0); 93 } 94 95 int 96 control_listen(void) 97 { 98 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 99 log_warn("%s: listen", __func__); 100 return (-1); 101 } 102 103 event_set(&control_state.ev, control_state.fd, EV_READ, 104 control_accept, NULL); 105 event_add(&control_state.ev, NULL); 106 evtimer_set(&control_state.evt, control_accept, NULL); 107 108 return (0); 109 } 110 111 static void 112 control_accept(int listenfd, short event, void *bula) 113 { 114 int connfd; 115 socklen_t len; 116 struct sockaddr_un sun; 117 struct ctl_conn *c; 118 119 event_add(&control_state.ev, NULL); 120 if ((event & EV_TIMEOUT)) 121 return; 122 123 len = sizeof(sun); 124 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 125 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 126 /* 127 * Pause accept if we are out of file descriptors, or 128 * libevent will haunt us here too. 129 */ 130 if (errno == ENFILE || errno == EMFILE) { 131 struct timeval evtpause = { 1, 0 }; 132 133 event_del(&control_state.ev); 134 evtimer_add(&control_state.evt, &evtpause); 135 } else if (errno != EWOULDBLOCK && errno != EINTR && 136 errno != ECONNABORTED) 137 log_warn("%s: accept4", __func__); 138 return; 139 } 140 141 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 142 log_warn("%s: calloc", __func__); 143 close(connfd); 144 return; 145 } 146 147 imsg_init(&c->iev.ibuf, connfd); 148 c->iev.handler = control_dispatch_imsg; 149 c->iev.events = EV_READ; 150 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 151 c->iev.handler, &c->iev); 152 event_add(&c->iev.ev, NULL); 153 154 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 155 } 156 157 static struct ctl_conn * 158 control_connbyfd(int fd) 159 { 160 struct ctl_conn *c; 161 162 TAILQ_FOREACH(c, &ctl_conns, entry) { 163 if (c->iev.ibuf.fd == fd) 164 break; 165 } 166 167 return (c); 168 } 169 170 static struct ctl_conn * 171 control_connbypid(pid_t pid) 172 { 173 struct ctl_conn *c; 174 175 TAILQ_FOREACH(c, &ctl_conns, entry) { 176 if (c->iev.ibuf.pid == pid) 177 break; 178 } 179 180 return (c); 181 } 182 183 static void 184 control_close(int fd) 185 { 186 struct ctl_conn *c; 187 188 if ((c = control_connbyfd(fd)) == NULL) { 189 log_warnx("%s: fd %d: not found", __func__, fd); 190 return; 191 } 192 193 msgbuf_clear(&c->iev.ibuf.w); 194 TAILQ_REMOVE(&ctl_conns, c, entry); 195 196 event_del(&c->iev.ev); 197 close(c->iev.ibuf.fd); 198 199 /* Some file descriptors are available again. */ 200 if (evtimer_pending(&control_state.evt, NULL)) { 201 evtimer_del(&control_state.evt); 202 event_add(&control_state.ev, NULL); 203 } 204 205 free(c); 206 } 207 208 static void 209 control_dispatch_imsg(int fd, short event, void *bula) 210 { 211 struct ctl_conn *c; 212 struct imsg imsg; 213 ssize_t n; 214 unsigned int ifidx; 215 int verbose; 216 217 if ((c = control_connbyfd(fd)) == NULL) { 218 log_warnx("%s: fd %d: not found", __func__, fd); 219 return; 220 } 221 222 if (event & EV_READ) { 223 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 224 n == 0) { 225 control_close(fd); 226 return; 227 } 228 } 229 if (event & EV_WRITE) { 230 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 231 control_close(fd); 232 return; 233 } 234 } 235 236 for (;;) { 237 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 238 control_close(fd); 239 return; 240 } 241 242 if (n == 0) 243 break; 244 245 switch (imsg.hdr.type) { 246 case IMSG_CTL_FIB_COUPLE: 247 case IMSG_CTL_FIB_DECOUPLE: 248 case IMSG_CTL_RELOAD: 249 c->iev.ibuf.pid = imsg.hdr.pid; 250 eigrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 251 break; 252 case IMSG_CTL_KROUTE: 253 case IMSG_CTL_IFINFO: 254 c->iev.ibuf.pid = imsg.hdr.pid; 255 eigrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 256 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 257 break; 258 case IMSG_CTL_SHOW_INTERFACE: 259 if (imsg.hdr.len != IMSG_HEADER_SIZE + 260 sizeof(ifidx)) 261 break; 262 263 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 264 eigrpe_iface_ctl(c, ifidx); 265 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 266 0, -1, NULL, 0); 267 break; 268 case IMSG_CTL_SHOW_TOPOLOGY: 269 if (imsg.hdr.len != IMSG_HEADER_SIZE + 270 sizeof(struct ctl_show_topology_req)) 271 break; 272 273 c->iev.ibuf.pid = imsg.hdr.pid; 274 eigrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 275 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 276 break; 277 case IMSG_CTL_SHOW_NBR: 278 eigrpe_nbr_ctl(c); 279 break; 280 case IMSG_CTL_SHOW_STATS: 281 eigrpe_stats_ctl(c); 282 break; 283 case IMSG_CTL_CLEAR_NBR: 284 if (imsg.hdr.len != IMSG_HEADER_SIZE + 285 sizeof(struct ctl_nbr)) 286 break; 287 288 nbr_clear_ctl(imsg.data); 289 break; 290 case IMSG_CTL_LOG_VERBOSE: 291 if (imsg.hdr.len != IMSG_HEADER_SIZE + 292 sizeof(verbose)) 293 break; 294 295 /* forward to other processes */ 296 eigrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 297 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 298 eigrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 299 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 300 301 memcpy(&verbose, imsg.data, sizeof(verbose)); 302 log_verbose(verbose); 303 break; 304 default: 305 log_debug("%s: error handling imsg %d", __func__, 306 imsg.hdr.type); 307 break; 308 } 309 imsg_free(&imsg); 310 } 311 312 imsg_event_add(&c->iev); 313 } 314 315 int 316 control_imsg_relay(struct imsg *imsg) 317 { 318 struct ctl_conn *c; 319 320 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 321 return (0); 322 323 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 324 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 325 } 326