1 /* $OpenBSD: control.c,v 1.26 2018/11/04 07:52:55 remi 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 "ripd.h" 30 #include "rip.h" 31 #include "ripe.h" 32 #include "log.h" 33 #include "control.h" 34 35 #define CONTROL_BACKLOG 5 36 37 struct ctl_conn *control_connbyfd(int); 38 struct ctl_conn *control_connbypid(pid_t); 39 void control_close(int); 40 41 int 42 control_init(char *path) 43 { 44 struct sockaddr_un sun; 45 int fd; 46 mode_t old_umask; 47 48 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 49 0)) == -1) { 50 log_warn("control_init: socket"); 51 return (-1); 52 } 53 54 bzero(&sun, sizeof(sun)); 55 sun.sun_family = AF_UNIX; 56 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 57 58 if (unlink(path) == -1) 59 if (errno != ENOENT) { 60 log_warn("control_init: unlink %s", path); 61 close(fd); 62 return (-1); 63 } 64 65 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 66 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 67 log_warn("control_init: bind: %s", path); 68 close(fd); 69 umask(old_umask); 70 return (-1); 71 } 72 umask(old_umask); 73 74 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 75 log_warn("control_init: chmod"); 76 close(fd); 77 (void)unlink(path); 78 return (-1); 79 } 80 81 control_state.fd = fd; 82 83 return (0); 84 } 85 86 int 87 control_listen(void) 88 { 89 90 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 91 log_warn("control_listen: listen"); 92 return (-1); 93 } 94 95 event_set(&control_state.ev, control_state.fd, EV_READ, 96 control_accept, NULL); 97 event_add(&control_state.ev, NULL); 98 evtimer_set(&control_state.evt, control_accept, NULL); 99 100 return (0); 101 } 102 103 /* ARGSUSED */ 104 void 105 control_accept(int listenfd, short event, void *bula) 106 { 107 int connfd; 108 socklen_t len; 109 struct sockaddr_un sun; 110 struct ctl_conn *c; 111 112 event_add(&control_state.ev, NULL); 113 if ((event & EV_TIMEOUT)) 114 return; 115 116 len = sizeof(sun); 117 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 118 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 119 /* 120 * Pause accept if we are out of file descriptors, or 121 * libevent will haunt us here too. 122 */ 123 if (errno == ENFILE || errno == EMFILE) { 124 struct timeval evtpause = { 1, 0 }; 125 126 event_del(&control_state.ev); 127 evtimer_add(&control_state.evt, &evtpause); 128 } else if (errno != EWOULDBLOCK && errno != EINTR && 129 errno != ECONNABORTED) 130 log_warn("control_accept: accept"); 131 return; 132 } 133 134 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 135 log_warn("control_accept"); 136 close(connfd); 137 return; 138 } 139 140 imsg_init(&c->iev.ibuf, connfd); 141 c->iev.handler = control_dispatch_imsg; 142 c->iev.events = EV_READ; 143 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 144 c->iev.handler, &c->iev); 145 event_add(&c->iev.ev, NULL); 146 147 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 148 } 149 150 struct ctl_conn * 151 control_connbyfd(int fd) 152 { 153 struct ctl_conn *c; 154 155 TAILQ_FOREACH(c, &ctl_conns, entry) { 156 if (c->iev.ibuf.fd == fd) 157 break; 158 } 159 160 return (c); 161 } 162 163 struct ctl_conn * 164 control_connbypid(pid_t pid) 165 { 166 struct ctl_conn *c; 167 168 TAILQ_FOREACH(c, &ctl_conns, entry) { 169 if (c->iev.ibuf.pid == pid) 170 break; 171 } 172 173 return (c); 174 } 175 176 void 177 control_close(int fd) 178 { 179 struct ctl_conn *c; 180 181 if ((c = control_connbyfd(fd)) == NULL) { 182 log_warn("control_close: fd %d: not found", fd); 183 return; 184 } 185 186 msgbuf_clear(&c->iev.ibuf.w); 187 TAILQ_REMOVE(&ctl_conns, c, entry); 188 189 event_del(&c->iev.ev); 190 close(c->iev.ibuf.fd); 191 192 /* Some file descriptors are available again. */ 193 if (evtimer_pending(&control_state.evt, NULL)) { 194 evtimer_del(&control_state.evt); 195 event_add(&control_state.ev, NULL); 196 } 197 198 free(c); 199 } 200 201 /* ARGSUSED */ 202 void 203 control_dispatch_imsg(int fd, short event, void *bula) 204 { 205 struct ctl_conn *c; 206 struct imsg imsg; 207 ssize_t n; 208 unsigned int ifidx; 209 int verbose; 210 211 if ((c = control_connbyfd(fd)) == NULL) { 212 log_warn("control_dispatch_imsg: fd %d: not found", fd); 213 return; 214 } 215 216 if (event & EV_READ) { 217 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 218 n == 0) { 219 control_close(fd); 220 return; 221 } 222 } 223 if (event & EV_WRITE) { 224 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 225 control_close(fd); 226 return; 227 } 228 } 229 230 for (;;) { 231 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 232 control_close(fd); 233 return; 234 } 235 236 if (n == 0) 237 break; 238 239 switch (imsg.hdr.type) { 240 case IMSG_CTL_SHOW_INTERFACE: 241 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(ifidx)) 242 return; 243 244 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 245 ripe_iface_ctl(c, ifidx); 246 imsg_compose(&c->iev.ibuf, IMSG_CTL_END, 0, 0, 247 -1, NULL, 0); 248 249 break; 250 case IMSG_CTL_SHOW_RIB: 251 c->iev.ibuf.pid = imsg.hdr.pid; 252 ripe_imsg_compose_rde(imsg.hdr.type, 0, 253 imsg.hdr.pid, imsg.data, imsg.hdr.len - 254 IMSG_HEADER_SIZE); 255 break; 256 case IMSG_CTL_SHOW_NBR: 257 ripe_nbr_ctl(c); 258 break; 259 case IMSG_CTL_KROUTE_ADDR: 260 case IMSG_CTL_KROUTE: 261 case IMSG_CTL_IFINFO: 262 c->iev.ibuf.pid = imsg.hdr.pid; 263 ripe_imsg_compose_parent(imsg.hdr.type, 264 imsg.hdr.pid, imsg.data, 265 imsg.hdr.len - IMSG_HEADER_SIZE); 266 break; 267 case IMSG_CTL_FIB_COUPLE: 268 case IMSG_CTL_FIB_DECOUPLE: 269 case IMSG_CTL_RELOAD: 270 c->iev.ibuf.pid = imsg.hdr.pid; 271 ripe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 272 break; 273 case IMSG_CTL_LOG_VERBOSE: 274 if (imsg.hdr.len != IMSG_HEADER_SIZE + 275 sizeof(verbose)) 276 break; 277 278 /* forward to other processes */ 279 ripe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 280 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 281 ripe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 282 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 283 284 memcpy(&verbose, imsg.data, sizeof(verbose)); 285 log_verbose(verbose); 286 break; 287 default: 288 log_debug("control_dispatch_imsg: " 289 "error handling imsg %d", imsg.hdr.type); 290 break; 291 } 292 imsg_free(&imsg); 293 } 294 295 imsg_event_add(&c->iev); 296 } 297 298 int 299 control_imsg_relay(struct imsg *imsg) 300 { 301 struct ctl_conn *c; 302 303 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 304 return (0); 305 306 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 307 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 308 } 309