1 /* $OpenBSD: control.c,v 1.27 2021/01/19 10:00:36 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 "ripd.h" 30 #include "rip.h" 31 #include "ripe.h" 32 #include "log.h" 33 #include "control.h" 34 35 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 36 37 #define CONTROL_BACKLOG 5 38 39 struct ctl_conn *control_connbyfd(int); 40 struct ctl_conn *control_connbypid(pid_t); 41 void control_close(int); 42 43 struct { 44 struct event ev; 45 struct event evt; 46 int fd; 47 } control_state; 48 49 int 50 control_init(char *path) 51 { 52 struct sockaddr_un sun; 53 int fd; 54 mode_t old_umask; 55 56 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 57 0)) == -1) { 58 log_warn("control_init: socket"); 59 return (-1); 60 } 61 62 bzero(&sun, sizeof(sun)); 63 sun.sun_family = AF_UNIX; 64 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 65 66 if (unlink(path) == -1) 67 if (errno != ENOENT) { 68 log_warn("control_init: unlink %s", path); 69 close(fd); 70 return (-1); 71 } 72 73 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 74 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 75 log_warn("control_init: bind: %s", path); 76 close(fd); 77 umask(old_umask); 78 return (-1); 79 } 80 umask(old_umask); 81 82 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 83 log_warn("control_init: chmod"); 84 close(fd); 85 (void)unlink(path); 86 return (-1); 87 } 88 89 control_state.fd = fd; 90 91 return (0); 92 } 93 94 int 95 control_listen(void) 96 { 97 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 98 log_warn("control_listen: listen"); 99 return (-1); 100 } 101 102 event_set(&control_state.ev, control_state.fd, EV_READ, 103 control_accept, NULL); 104 event_add(&control_state.ev, NULL); 105 evtimer_set(&control_state.evt, control_accept, NULL); 106 107 return (0); 108 } 109 110 /* ARGSUSED */ 111 void 112 control_accept(int listenfd, short event, void *bula) 113 { 114 int connfd; 115 socklen_t len; 116 struct sockaddr_un sun; 117 struct ctl_conn *c; 118 119 event_add(&control_state.ev, NULL); 120 if ((event & EV_TIMEOUT)) 121 return; 122 123 len = sizeof(sun); 124 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 125 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 126 /* 127 * Pause accept if we are out of file descriptors, or 128 * libevent will haunt us here too. 129 */ 130 if (errno == ENFILE || errno == EMFILE) { 131 struct timeval evtpause = { 1, 0 }; 132 133 event_del(&control_state.ev); 134 evtimer_add(&control_state.evt, &evtpause); 135 } else if (errno != EWOULDBLOCK && errno != EINTR && 136 errno != ECONNABORTED) 137 log_warn("control_accept: accept"); 138 return; 139 } 140 141 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 142 log_warn("control_accept"); 143 close(connfd); 144 return; 145 } 146 147 imsg_init(&c->iev.ibuf, connfd); 148 c->iev.handler = control_dispatch_imsg; 149 c->iev.events = EV_READ; 150 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 151 c->iev.handler, &c->iev); 152 event_add(&c->iev.ev, NULL); 153 154 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 155 } 156 157 struct ctl_conn * 158 control_connbyfd(int fd) 159 { 160 struct ctl_conn *c; 161 162 TAILQ_FOREACH(c, &ctl_conns, entry) { 163 if (c->iev.ibuf.fd == fd) 164 break; 165 } 166 167 return (c); 168 } 169 170 struct ctl_conn * 171 control_connbypid(pid_t pid) 172 { 173 struct ctl_conn *c; 174 175 TAILQ_FOREACH(c, &ctl_conns, entry) { 176 if (c->iev.ibuf.pid == pid) 177 break; 178 } 179 180 return (c); 181 } 182 183 void 184 control_close(int fd) 185 { 186 struct ctl_conn *c; 187 188 if ((c = control_connbyfd(fd)) == NULL) { 189 log_warn("control_close: fd %d: not found", fd); 190 return; 191 } 192 193 msgbuf_clear(&c->iev.ibuf.w); 194 TAILQ_REMOVE(&ctl_conns, c, entry); 195 196 event_del(&c->iev.ev); 197 close(c->iev.ibuf.fd); 198 199 /* Some file descriptors are available again. */ 200 if (evtimer_pending(&control_state.evt, NULL)) { 201 evtimer_del(&control_state.evt); 202 event_add(&control_state.ev, NULL); 203 } 204 205 free(c); 206 } 207 208 /* ARGSUSED */ 209 void 210 control_dispatch_imsg(int fd, short event, void *bula) 211 { 212 struct ctl_conn *c; 213 struct imsg imsg; 214 ssize_t n; 215 unsigned int ifidx; 216 int verbose; 217 218 if ((c = control_connbyfd(fd)) == NULL) { 219 log_warn("control_dispatch_imsg: fd %d: not found", fd); 220 return; 221 } 222 223 if (event & EV_READ) { 224 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 225 n == 0) { 226 control_close(fd); 227 return; 228 } 229 } 230 if (event & EV_WRITE) { 231 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 232 control_close(fd); 233 return; 234 } 235 } 236 237 for (;;) { 238 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 239 control_close(fd); 240 return; 241 } 242 243 if (n == 0) 244 break; 245 246 switch (imsg.hdr.type) { 247 case IMSG_CTL_SHOW_INTERFACE: 248 if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(ifidx)) 249 return; 250 251 memcpy(&ifidx, imsg.data, sizeof(ifidx)); 252 ripe_iface_ctl(c, ifidx); 253 imsg_compose(&c->iev.ibuf, IMSG_CTL_END, 0, 0, 254 -1, NULL, 0); 255 256 break; 257 case IMSG_CTL_SHOW_RIB: 258 c->iev.ibuf.pid = imsg.hdr.pid; 259 ripe_imsg_compose_rde(imsg.hdr.type, 0, 260 imsg.hdr.pid, imsg.data, imsg.hdr.len - 261 IMSG_HEADER_SIZE); 262 break; 263 case IMSG_CTL_SHOW_NBR: 264 ripe_nbr_ctl(c); 265 break; 266 case IMSG_CTL_KROUTE_ADDR: 267 case IMSG_CTL_KROUTE: 268 case IMSG_CTL_IFINFO: 269 c->iev.ibuf.pid = imsg.hdr.pid; 270 ripe_imsg_compose_parent(imsg.hdr.type, 271 imsg.hdr.pid, imsg.data, 272 imsg.hdr.len - IMSG_HEADER_SIZE); 273 break; 274 case IMSG_CTL_FIB_COUPLE: 275 case IMSG_CTL_FIB_DECOUPLE: 276 case IMSG_CTL_RELOAD: 277 c->iev.ibuf.pid = imsg.hdr.pid; 278 ripe_imsg_compose_parent(imsg.hdr.type, 0, NULL, 0); 279 break; 280 case IMSG_CTL_LOG_VERBOSE: 281 if (imsg.hdr.len != IMSG_HEADER_SIZE + 282 sizeof(verbose)) 283 break; 284 285 /* forward to other processes */ 286 ripe_imsg_compose_parent(imsg.hdr.type, imsg.hdr.pid, 287 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 288 ripe_imsg_compose_rde(imsg.hdr.type, 0, imsg.hdr.pid, 289 imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE); 290 291 memcpy(&verbose, imsg.data, sizeof(verbose)); 292 log_verbose(verbose); 293 break; 294 default: 295 log_debug("control_dispatch_imsg: " 296 "error handling imsg %d", imsg.hdr.type); 297 break; 298 } 299 imsg_free(&imsg); 300 } 301 302 imsg_event_add(&c->iev); 303 } 304 305 int 306 control_imsg_relay(struct imsg *imsg) 307 { 308 struct ctl_conn *c; 309 310 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 311 return (0); 312 313 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 314 -1, imsg->data, imsg->hdr.len - IMSG_HEADER_SIZE)); 315 } 316