1 /* $OpenBSD: control.c,v 1.24 2021/01/19 12:23:30 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 /* ARGSUSED */ 120 void 121 control_accept(int listenfd, short event, void *bula) 122 { 123 int connfd; 124 socklen_t len; 125 struct sockaddr_un sun; 126 struct ctl_conn *c; 127 128 event_add(&control_state.ev, NULL); 129 if ((event & EV_TIMEOUT)) 130 return; 131 132 len = sizeof(sun); 133 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 134 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) { 135 /* 136 * Pause accept if we are out of file descriptors, or 137 * libevent will haunt us here too. 138 */ 139 if (errno == ENFILE || errno == EMFILE) { 140 struct timeval evtpause = { 1, 0 }; 141 142 event_del(&control_state.ev); 143 evtimer_add(&control_state.evt, &evtpause); 144 } else if (errno != EWOULDBLOCK && errno != EINTR && 145 errno != ECONNABORTED) 146 log_warn("control_accept: accept"); 147 return; 148 } 149 150 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 151 log_warn("control_accept"); 152 close(connfd); 153 return; 154 } 155 156 imsg_init(&c->iev.ibuf, connfd); 157 c->iev.handler = control_dispatch_imsg; 158 c->iev.events = EV_READ; 159 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 160 c->iev.handler, &c->iev); 161 event_add(&c->iev.ev, NULL); 162 163 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 164 } 165 166 struct ctl_conn * 167 control_connbyfd(int fd) 168 { 169 struct ctl_conn *c; 170 171 TAILQ_FOREACH(c, &ctl_conns, entry) { 172 if (c->iev.ibuf.fd == fd) 173 break; 174 } 175 176 return (c); 177 } 178 179 struct ctl_conn * 180 control_connbypid(pid_t pid) 181 { 182 struct ctl_conn *c; 183 184 TAILQ_FOREACH(c, &ctl_conns, entry) { 185 if (c->iev.ibuf.pid == pid) 186 break; 187 } 188 189 return (c); 190 } 191 192 void 193 control_close(int fd) 194 { 195 struct ctl_conn *c; 196 197 if ((c = control_connbyfd(fd)) == NULL) { 198 log_warn("control_close: fd %d: not found", fd); 199 return; 200 } 201 202 msgbuf_clear(&c->iev.ibuf.w); 203 TAILQ_REMOVE(&ctl_conns, c, entry); 204 205 event_del(&c->iev.ev); 206 close(c->iev.ibuf.fd); 207 208 /* Some file descriptors are available again. */ 209 if (evtimer_pending(&control_state.evt, NULL)) { 210 evtimer_del(&control_state.evt); 211 event_add(&control_state.ev, NULL); 212 } 213 214 free(c); 215 } 216 217 /* ARGSUSED */ 218 void 219 control_dispatch_imsg(int fd, short event, void *bula) 220 { 221 struct ctl_conn *c; 222 struct imsg imsg; 223 int n; 224 unsigned int ifidx; 225 int verbose; 226 227 if ((c = control_connbyfd(fd)) == NULL) { 228 log_warn("control_dispatch_imsg: fd %d: not found", fd); 229 return; 230 } 231 232 if (event & EV_READ) { 233 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 234 n == 0) { 235 control_close(fd); 236 return; 237 } 238 } 239 if (event & EV_WRITE) { 240 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 241 control_close(fd); 242 return; 243 } 244 } 245 246 for (;;) { 247 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 248 control_close(fd); 249 return; 250 } 251 252 if (n == 0) 253 break; 254 255 switch (imsg.hdr.type) { 256 case IMSG_CTL_MFC_COUPLE: 257 case IMSG_CTL_MFC_DECOUPLE: 258 case IMSG_CTL_RELOAD: 259 dvmrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 260 break; 261 case IMSG_CTL_SHOW_IFACE: 262 if (imsg.hdr.len == IMSG_HEADER_SIZE + 263 sizeof(ifidx)) { 264 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 265 dvmrpe_iface_ctl(c, ifidx); 266 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 267 0, -1, NULL, 0); 268 } 269 break; 270 case IMSG_CTL_SHOW_IGMP: 271 if (imsg.hdr.len == IMSG_HEADER_SIZE + 272 sizeof(ifidx)) { 273 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 274 dvmrpe_iface_igmp_ctl(c, ifidx); 275 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 276 0, -1, NULL, 0); 277 } 278 break; 279 case IMSG_CTL_SHOW_NBR: 280 dvmrpe_nbr_ctl(c); 281 break; 282 case IMSG_CTL_SHOW_RIB: 283 case IMSG_CTL_SHOW_MFC: 284 case IMSG_CTL_SHOW_SUM: 285 c->iev.ibuf.pid = imsg.hdr.pid; 286 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 287 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 288 break; 289 case IMSG_CTL_LOG_VERBOSE: 290 if (imsg.hdr.len != IMSG_HEADER_SIZE + 291 sizeof(verbose)) 292 break; 293 294 /* forward to other processes */ 295 dvmrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 296 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 297 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 298 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 299 300 memcpy(&verbose, imsg.data, sizeof(verbose)); 301 log_verbose(verbose); 302 break; 303 default: 304 log_debug("control_dispatch_imsg: " 305 "error handling imsg %d", imsg.hdr.type); 306 break; 307 } 308 imsg_free(&imsg); 309 } 310 311 imsg_event_add(&c->iev); 312 } 313 314 int 315 control_imsg_relay(struct imsg *imsg) 316 { 317 struct ctl_conn *c; 318 319 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 320 return (0); 321 322 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 323 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 324 } 325