1 /* $OpenBSD: control.c,v 1.25 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/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 imsg_init(&c->iev.ibuf, connfd); 156 c->iev.handler = control_dispatch_imsg; 157 c->iev.events = EV_READ; 158 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 159 c->iev.handler, &c->iev); 160 event_add(&c->iev.ev, NULL); 161 162 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 163 } 164 165 struct ctl_conn * 166 control_connbyfd(int fd) 167 { 168 struct ctl_conn *c; 169 170 TAILQ_FOREACH(c, &ctl_conns, entry) { 171 if (c->iev.ibuf.fd == fd) 172 break; 173 } 174 175 return (c); 176 } 177 178 struct ctl_conn * 179 control_connbypid(pid_t pid) 180 { 181 struct ctl_conn *c; 182 183 TAILQ_FOREACH(c, &ctl_conns, entry) { 184 if (c->iev.ibuf.pid == pid) 185 break; 186 } 187 188 return (c); 189 } 190 191 void 192 control_close(int fd) 193 { 194 struct ctl_conn *c; 195 196 if ((c = control_connbyfd(fd)) == NULL) { 197 log_warn("control_close: fd %d: not found", fd); 198 return; 199 } 200 201 msgbuf_clear(&c->iev.ibuf.w); 202 TAILQ_REMOVE(&ctl_conns, c, entry); 203 204 event_del(&c->iev.ev); 205 close(c->iev.ibuf.fd); 206 207 /* Some file descriptors are available again. */ 208 if (evtimer_pending(&control_state.evt, NULL)) { 209 evtimer_del(&control_state.evt); 210 event_add(&control_state.ev, NULL); 211 } 212 213 free(c); 214 } 215 216 void 217 control_dispatch_imsg(int fd, short event, void *bula) 218 { 219 struct ctl_conn *c; 220 struct imsg imsg; 221 int n; 222 unsigned int ifidx; 223 int verbose; 224 225 if ((c = control_connbyfd(fd)) == NULL) { 226 log_warn("control_dispatch_imsg: fd %d: not found", fd); 227 return; 228 } 229 230 if (event & EV_READ) { 231 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 232 n == 0) { 233 control_close(fd); 234 return; 235 } 236 } 237 if (event & EV_WRITE) { 238 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 239 control_close(fd); 240 return; 241 } 242 } 243 244 for (;;) { 245 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 246 control_close(fd); 247 return; 248 } 249 250 if (n == 0) 251 break; 252 253 switch (imsg.hdr.type) { 254 case IMSG_CTL_MFC_COUPLE: 255 case IMSG_CTL_MFC_DECOUPLE: 256 case IMSG_CTL_RELOAD: 257 dvmrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 258 break; 259 case IMSG_CTL_SHOW_IFACE: 260 if (imsg.hdr.len == IMSG_HEADER_SIZE + 261 sizeof(ifidx)) { 262 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 263 dvmrpe_iface_ctl(c, ifidx); 264 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 265 0, -1, NULL, 0); 266 } 267 break; 268 case IMSG_CTL_SHOW_IGMP: 269 if (imsg.hdr.len == IMSG_HEADER_SIZE + 270 sizeof(ifidx)) { 271 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 272 dvmrpe_iface_igmp_ctl(c, ifidx); 273 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 274 0, -1, NULL, 0); 275 } 276 break; 277 case IMSG_CTL_SHOW_NBR: 278 dvmrpe_nbr_ctl(c); 279 break; 280 case IMSG_CTL_SHOW_RIB: 281 case IMSG_CTL_SHOW_MFC: 282 case IMSG_CTL_SHOW_SUM: 283 c->iev.ibuf.pid = imsg.hdr.pid; 284 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 285 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 286 break; 287 case IMSG_CTL_LOG_VERBOSE: 288 if (imsg.hdr.len != IMSG_HEADER_SIZE + 289 sizeof(verbose)) 290 break; 291 292 /* forward to other processes */ 293 dvmrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 294 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 295 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 296 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 297 298 memcpy(&verbose, imsg.data, sizeof(verbose)); 299 log_verbose(verbose); 300 break; 301 default: 302 log_debug("control_dispatch_imsg: " 303 "error handling imsg %d", imsg.hdr.type); 304 break; 305 } 306 imsg_free(&imsg); 307 } 308 309 imsg_event_add(&c->iev); 310 } 311 312 int 313 control_imsg_relay(struct imsg *imsg) 314 { 315 struct ctl_conn *c; 316 317 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 318 return (0); 319 320 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 321 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 322 } 323