1 /* $OpenBSD: control.c,v 1.23 2017/01/08 23:04:42 krw 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 #define CONTROL_BACKLOG 5 37 38 struct ctl_conn *control_connbyfd(int); 39 struct ctl_conn *control_connbypid(pid_t); 40 void control_close(int); 41 42 int 43 control_init(void) 44 { 45 struct sockaddr_un sun; 46 int fd; 47 mode_t old_umask; 48 49 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 50 0)) == -1) { 51 log_warn("control_init: socket"); 52 return (-1); 53 } 54 55 memset(&sun, 0, sizeof(sun)); 56 sun.sun_family = AF_UNIX; 57 strlcpy(sun.sun_path, DVMRPD_SOCKET, sizeof(sun.sun_path)); 58 59 if (unlink(DVMRPD_SOCKET) == -1) 60 if (errno != ENOENT) { 61 log_warn("control_init: unlink %s", DVMRPD_SOCKET); 62 close(fd); 63 return (-1); 64 } 65 66 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 67 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 68 log_warn("control_init: bind: %s", DVMRPD_SOCKET); 69 close(fd); 70 umask(old_umask); 71 return (-1); 72 } 73 umask(old_umask); 74 75 if (chmod(DVMRPD_SOCKET, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 76 log_warn("control_init: chmod"); 77 close(fd); 78 (void)unlink(DVMRPD_SOCKET); 79 return (-1); 80 } 81 82 control_state.fd = fd; 83 84 return (0); 85 } 86 87 int 88 control_listen(void) 89 { 90 91 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 92 log_warn("control_listen: listen"); 93 return (-1); 94 } 95 96 event_set(&control_state.ev, control_state.fd, EV_READ, 97 control_accept, NULL); 98 event_add(&control_state.ev, NULL); 99 evtimer_set(&control_state.evt, control_accept, NULL); 100 101 return (0); 102 } 103 104 void 105 control_cleanup(void) 106 { 107 event_del(&control_state.ev); 108 event_del(&control_state.evt); 109 unlink(DVMRPD_SOCKET); 110 } 111 112 /* ARGSUSED */ 113 void 114 control_accept(int listenfd, short event, void *bula) 115 { 116 int connfd; 117 socklen_t len; 118 struct sockaddr_un sun; 119 struct ctl_conn *c; 120 121 event_add(&control_state.ev, NULL); 122 if ((event & EV_TIMEOUT)) 123 return; 124 125 len = sizeof(sun); 126 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 127 SOCK_NONBLOCK | SOCK_CLOEXEC)) == -1) { 128 /* 129 * Pause accept if we are out of file descriptors, or 130 * libevent will haunt us here too. 131 */ 132 if (errno == ENFILE || errno == EMFILE) { 133 struct timeval evtpause = { 1, 0 }; 134 135 event_del(&control_state.ev); 136 evtimer_add(&control_state.evt, &evtpause); 137 } else if (errno != EWOULDBLOCK && errno != EINTR && 138 errno != ECONNABORTED) 139 log_warn("control_accept: accept"); 140 return; 141 } 142 143 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 144 log_warn("control_accept"); 145 close(connfd); 146 return; 147 } 148 149 imsg_init(&c->iev.ibuf, connfd); 150 c->iev.handler = control_dispatch_imsg; 151 c->iev.events = EV_READ; 152 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 153 c->iev.handler, &c->iev); 154 event_add(&c->iev.ev, NULL); 155 156 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 157 } 158 159 struct ctl_conn * 160 control_connbyfd(int fd) 161 { 162 struct ctl_conn *c; 163 164 TAILQ_FOREACH(c, &ctl_conns, entry) { 165 if (c->iev.ibuf.fd == fd) 166 break; 167 } 168 169 return (c); 170 } 171 172 struct ctl_conn * 173 control_connbypid(pid_t pid) 174 { 175 struct ctl_conn *c; 176 177 TAILQ_FOREACH(c, &ctl_conns, entry) { 178 if (c->iev.ibuf.pid == pid) 179 break; 180 } 181 182 return (c); 183 } 184 185 void 186 control_close(int fd) 187 { 188 struct ctl_conn *c; 189 190 if ((c = control_connbyfd(fd)) == NULL) { 191 log_warn("control_close: fd %d: not found", fd); 192 return; 193 } 194 195 msgbuf_clear(&c->iev.ibuf.w); 196 TAILQ_REMOVE(&ctl_conns, c, entry); 197 198 event_del(&c->iev.ev); 199 close(c->iev.ibuf.fd); 200 201 /* Some file descriptors are available again. */ 202 if (evtimer_pending(&control_state.evt, NULL)) { 203 evtimer_del(&control_state.evt); 204 event_add(&control_state.ev, NULL); 205 } 206 207 free(c); 208 } 209 210 /* ARGSUSED */ 211 void 212 control_dispatch_imsg(int fd, short event, void *bula) 213 { 214 struct ctl_conn *c; 215 struct imsg imsg; 216 int n; 217 unsigned int ifidx; 218 int verbose; 219 220 if ((c = control_connbyfd(fd)) == NULL) { 221 log_warn("control_dispatch_imsg: fd %d: not found", fd); 222 return; 223 } 224 225 if (event & EV_READ) { 226 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 227 n == 0) { 228 control_close(fd); 229 return; 230 } 231 } 232 if (event & EV_WRITE) { 233 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 234 control_close(fd); 235 return; 236 } 237 } 238 239 for (;;) { 240 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 241 control_close(fd); 242 return; 243 } 244 245 if (n == 0) 246 break; 247 248 switch (imsg.hdr.type) { 249 case IMSG_CTL_MFC_COUPLE: 250 case IMSG_CTL_MFC_DECOUPLE: 251 case IMSG_CTL_RELOAD: 252 dvmrpe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 253 break; 254 case IMSG_CTL_SHOW_IFACE: 255 if (imsg.hdr.len == IMSG_HEADER_SIZE + 256 sizeof(ifidx)) { 257 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 258 dvmrpe_iface_ctl(c, ifidx); 259 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 260 0, -1, NULL, 0); 261 } 262 break; 263 case IMSG_CTL_SHOW_IGMP: 264 if (imsg.hdr.len == IMSG_HEADER_SIZE + 265 sizeof(ifidx)) { 266 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 267 dvmrpe_iface_igmp_ctl(c, ifidx); 268 imsg_compose_event(&c->iev, IMSG_CTL_END, 0, 269 0, -1, NULL, 0); 270 } 271 break; 272 case IMSG_CTL_SHOW_NBR: 273 dvmrpe_nbr_ctl(c); 274 break; 275 case IMSG_CTL_SHOW_RIB: 276 case IMSG_CTL_SHOW_MFC: 277 case IMSG_CTL_SHOW_SUM: 278 c->iev.ibuf.pid = imsg.hdr.pid; 279 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 280 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 281 break; 282 case IMSG_CTL_LOG_VERBOSE: 283 if (imsg.hdr.len != IMSG_HEADER_SIZE + 284 sizeof(verbose)) 285 break; 286 287 /* forward to other processes */ 288 dvmrpe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 289 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 290 dvmrpe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 291 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 292 293 memcpy(&verbose, imsg.data, sizeof(verbose)); 294 log_verbose(verbose); 295 break; 296 default: 297 log_debug("control_dispatch_imsg: " 298 "error handling imsg %d", imsg.hdr.type); 299 break; 300 } 301 imsg_free(&imsg); 302 } 303 304 imsg_event_add(&c->iev); 305 } 306 307 int 308 control_imsg_relay(struct imsg *imsg) 309 { 310 struct ctl_conn *c; 311 312 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 313 return (0); 314 315 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 316 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 317 } 318