1 /* $OpenBSD: control.c,v 1.31 2024/11/21 13:38:14 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/types.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/un.h> 23 #include <errno.h> 24 #include <fcntl.h> 25 #include <stdlib.h> 26 #include <string.h> 27 #include <unistd.h> 28 29 #include "igmp.h" 30 #include "dvmrpd.h" 31 #include "dvmrp.h" 32 #include "dvmrpe.h" 33 #include "log.h" 34 #include "control.h" 35 36 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 37 38 #define CONTROL_BACKLOG 5 39 40 struct ctl_conn *control_connbyfd(int); 41 struct ctl_conn *control_connbypid(pid_t); 42 void control_close(int); 43 44 struct { 45 struct event ev; 46 struct event evt; 47 int fd; 48 } control_state; 49 50 int 51 control_init(void) 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("control_init: socket"); 60 return (-1); 61 } 62 63 memset(&sun, 0, sizeof(sun)); 64 sun.sun_family = AF_UNIX; 65 strlcpy(sun.sun_path, DVMRPD_SOCKET, sizeof(sun.sun_path)); 66 67 if (unlink(DVMRPD_SOCKET) == -1) 68 if (errno != ENOENT) { 69 log_warn("control_init: unlink %s", DVMRPD_SOCKET); 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("control_init: bind: %s", DVMRPD_SOCKET); 77 close(fd); 78 umask(old_umask); 79 return (-1); 80 } 81 umask(old_umask); 82 83 if (chmod(DVMRPD_SOCKET, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 84 log_warn("control_init: chmod"); 85 close(fd); 86 (void)unlink(DVMRPD_SOCKET); 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("control_listen: listen"); 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 void 112 control_cleanup(void) 113 { 114 event_del(&control_state.ev); 115 event_del(&control_state.evt); 116 unlink(DVMRPD_SOCKET); 117 } 118 119 void 120 control_accept(int listenfd, short event, void *bula) 121 { 122 int connfd; 123 socklen_t len; 124 struct sockaddr_un sun; 125 struct ctl_conn *c; 126 127 event_add(&control_state.ev, NULL); 128 if ((event & EV_TIMEOUT)) 129 return; 130 131 len = sizeof(sun); 132 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 133 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) { 134 /* 135 * Pause accept if we are out of file descriptors, or 136 * libevent will haunt us here too. 137 */ 138 if (errno == ENFILE || errno == EMFILE) { 139 struct timeval evtpause = { 1, 0 }; 140 141 event_del(&control_state.ev); 142 evtimer_add(&control_state.evt, &evtpause); 143 } else if (errno != EWOULDBLOCK && errno != EINTR && 144 errno != ECONNABORTED) 145 log_warn("control_accept: accept"); 146 return; 147 } 148 149 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 150 log_warn("control_accept"); 151 close(connfd); 152 return; 153 } 154 155 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) { 156 log_warn("control_accept"); 157 close(connfd); 158 free(c); 159 return; 160 } 161 162 c->iev.handler = control_dispatch_imsg; 163 c->iev.events = EV_READ; 164 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 165 c->iev.handler, &c->iev); 166 event_add(&c->iev.ev, NULL); 167 168 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 169 } 170 171 struct ctl_conn * 172 control_connbyfd(int fd) 173 { 174 struct ctl_conn *c; 175 176 TAILQ_FOREACH(c, &ctl_conns, entry) { 177 if (c->iev.ibuf.fd == fd) 178 break; 179 } 180 181 return (c); 182 } 183 184 struct ctl_conn * 185 control_connbypid(pid_t pid) 186 { 187 struct ctl_conn *c; 188 189 TAILQ_FOREACH(c, &ctl_conns, entry) { 190 if (c->iev.ibuf.pid == pid) 191 break; 192 } 193 194 return (c); 195 } 196 197 void 198 control_close(int fd) 199 { 200 struct ctl_conn *c; 201 202 if ((c = control_connbyfd(fd)) == NULL) { 203 log_warn("control_close: fd %d: not found", 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(&control_state.evt, NULL)) { 215 evtimer_del(&control_state.evt); 216 event_add(&control_state.ev, NULL); 217 } 218 219 free(c); 220 } 221 222 void 223 control_dispatch_imsg(int fd, short event, void *bula) 224 { 225 struct ctl_conn *c; 226 struct imsg imsg; 227 int n; 228 unsigned int ifidx; 229 int verbose; 230 231 if ((c = control_connbyfd(fd)) == NULL) { 232 log_warn("control_dispatch_imsg: fd %d: not found", fd); 233 return; 234 } 235 236 if (event & EV_READ) { 237 if (imsgbuf_read(&c->iev.ibuf) != 1) { 238 control_close(fd); 239 return; 240 } 241 } 242 if (event & EV_WRITE) { 243 if (imsgbuf_write(&c->iev.ibuf) == -1) { 244 control_close(fd); 245 return; 246 } 247 } 248 249 for (;;) { 250 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 251 control_close(fd); 252 return; 253 } 254 255 if (n == 0) 256 break; 257 258 switch (imsg.hdr.type) { 259 case IMSG_CTL_MFC_COUPLE: 260 case IMSG_CTL_MFC_DECOUPLE: 261 case IMSG_CTL_RELOAD: 262 dvmrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 263 break; 264 case IMSG_CTL_SHOW_IFACE: 265 if (imsg.hdr.len == IMSG_HEADER_SIZE + 266 sizeof(ifidx)) { 267 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 268 dvmrpe_iface_ctl(c, ifidx); 269 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 270 0, -1, NULL, 0); 271 } 272 break; 273 case IMSG_CTL_SHOW_IGMP: 274 if (imsg.hdr.len == IMSG_HEADER_SIZE + 275 sizeof(ifidx)) { 276 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 277 dvmrpe_iface_igmp_ctl(c, ifidx); 278 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 279 0, -1, NULL, 0); 280 } 281 break; 282 case IMSG_CTL_SHOW_NBR: 283 dvmrpe_nbr_ctl(c); 284 break; 285 case IMSG_CTL_SHOW_RIB: 286 case IMSG_CTL_SHOW_MFC: 287 case IMSG_CTL_SHOW_SUM: 288 c->iev.ibuf.pid = imsg.hdr.pid; 289 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 290 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 291 break; 292 case IMSG_CTL_LOG_VERBOSE: 293 if (imsg.hdr.len != IMSG_HEADER_SIZE + 294 sizeof(verbose)) 295 break; 296 297 /* forward to other processes */ 298 dvmrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 299 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 300 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 301 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 302 303 memcpy(&verbose, imsg.data, sizeof(verbose)); 304 log_verbose(verbose); 305 break; 306 default: 307 log_debug("control_dispatch_imsg: " 308 "error handling imsg %d", imsg.hdr.type); 309 break; 310 } 311 imsg_free(&imsg); 312 } 313 314 imsg_event_add(&c->iev); 315 } 316 317 int 318 control_imsg_relay(struct imsg *imsg) 319 { 320 struct ctl_conn *c; 321 322 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 323 return (0); 324 325 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 326 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 327 } 328