1 /* $OpenBSD: control.c,v 1.8 2021/03/02 04:10:07 jsg 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 #include <sys/types.h> 19 #include <sys/queue.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/uio.h> 23 #include <sys/un.h> 24 25 #include <netinet/in.h> 26 #include <net/if.h> 27 28 #include <errno.h> 29 #include <event.h> 30 #include <imsg.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <unistd.h> 34 35 #include "log.h" 36 #include "rad.h" 37 #include "control.h" 38 #include "frontend.h" 39 40 #define CONTROL_BACKLOG 5 41 42 struct { 43 struct event ev; 44 struct event evt; 45 int fd; 46 } control_state = {.fd = -1}; 47 48 struct ctl_conn { 49 TAILQ_ENTRY(ctl_conn) entry; 50 struct imsgev iev; 51 }; 52 53 TAILQ_HEAD(ctl_conns, ctl_conn) ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 54 55 struct ctl_conn *control_connbyfd(int); 56 struct ctl_conn *control_connbypid(pid_t); 57 void control_close(int); 58 59 int 60 control_init(char *path) 61 { 62 struct sockaddr_un sun; 63 int fd; 64 mode_t old_umask; 65 66 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 67 0)) == -1) { 68 log_warn("%s: socket", __func__); 69 return (-1); 70 } 71 72 memset(&sun, 0, sizeof(sun)); 73 sun.sun_family = AF_UNIX; 74 strlcpy(sun.sun_path, path, sizeof(sun.sun_path)); 75 76 if (unlink(path) == -1) 77 if (errno != ENOENT) { 78 log_warn("%s: unlink %s", __func__, path); 79 close(fd); 80 return (-1); 81 } 82 83 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 84 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 85 log_warn("%s: bind: %s", __func__, path); 86 close(fd); 87 umask(old_umask); 88 return (-1); 89 } 90 umask(old_umask); 91 92 if (chmod(path, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP) == -1) { 93 log_warn("%s: chmod", __func__); 94 close(fd); 95 (void)unlink(path); 96 return (-1); 97 } 98 99 return (fd); 100 } 101 102 int 103 control_listen(int fd) 104 { 105 if (control_state.fd != -1) 106 fatalx("%s: received unexpected controlsock", __func__); 107 108 control_state.fd = fd; 109 if (listen(control_state.fd, CONTROL_BACKLOG) == -1) { 110 log_warn("%s: listen", __func__); 111 return (-1); 112 } 113 114 event_set(&control_state.ev, control_state.fd, EV_READ, 115 control_accept, NULL); 116 event_add(&control_state.ev, NULL); 117 evtimer_set(&control_state.evt, control_accept, NULL); 118 119 return (0); 120 } 121 122 void 123 control_accept(int listenfd, short event, void *bula) 124 { 125 int connfd; 126 socklen_t len; 127 struct sockaddr_un sun; 128 struct ctl_conn *c; 129 130 event_add(&control_state.ev, NULL); 131 if ((event & EV_TIMEOUT)) 132 return; 133 134 len = sizeof(sun); 135 if ((connfd = accept4(listenfd, (struct sockaddr *)&sun, &len, 136 SOCK_CLOEXEC | SOCK_NONBLOCK)) == -1) { 137 /* 138 * Pause accept if we are out of file descriptors, or 139 * libevent will haunt us here too. 140 */ 141 if (errno == ENFILE || errno == EMFILE) { 142 struct timeval evtpause = { 1, 0 }; 143 144 event_del(&control_state.ev); 145 evtimer_add(&control_state.evt, &evtpause); 146 } else if (errno != EWOULDBLOCK && errno != EINTR && 147 errno != ECONNABORTED) 148 log_warn("%s: accept4", __func__); 149 return; 150 } 151 152 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 153 log_warn("%s: calloc", __func__); 154 close(connfd); 155 return; 156 } 157 158 imsg_init(&c->iev.ibuf, connfd); 159 c->iev.handler = control_dispatch_imsg; 160 c->iev.events = EV_READ; 161 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 162 c->iev.handler, &c->iev); 163 event_add(&c->iev.ev, NULL); 164 165 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 166 } 167 168 struct ctl_conn * 169 control_connbyfd(int fd) 170 { 171 struct ctl_conn *c; 172 173 TAILQ_FOREACH(c, &ctl_conns, entry) { 174 if (c->iev.ibuf.fd == fd) 175 break; 176 } 177 178 return (c); 179 } 180 181 struct ctl_conn * 182 control_connbypid(pid_t pid) 183 { 184 struct ctl_conn *c; 185 186 TAILQ_FOREACH(c, &ctl_conns, entry) { 187 if (c->iev.ibuf.pid == pid) 188 break; 189 } 190 191 return (c); 192 } 193 194 void 195 control_close(int fd) 196 { 197 struct ctl_conn *c; 198 199 if ((c = control_connbyfd(fd)) == NULL) { 200 log_warnx("%s: fd %d: not found", __func__, fd); 201 return; 202 } 203 204 msgbuf_clear(&c->iev.ibuf.w); 205 TAILQ_REMOVE(&ctl_conns, c, entry); 206 207 event_del(&c->iev.ev); 208 close(c->iev.ibuf.fd); 209 210 /* Some file descriptors are available again. */ 211 if (evtimer_pending(&control_state.evt, NULL)) { 212 evtimer_del(&control_state.evt); 213 event_add(&control_state.ev, NULL); 214 } 215 216 free(c); 217 } 218 219 void 220 control_dispatch_imsg(int fd, short event, void *bula) 221 { 222 struct ctl_conn *c; 223 struct imsg imsg; 224 ssize_t n; 225 int verbose; 226 227 if ((c = control_connbyfd(fd)) == NULL) { 228 log_warnx("%s: fd %d: not found", __func__, 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 if (n == 0) 252 break; 253 254 switch (imsg.hdr.type) { 255 case IMSG_CTL_RELOAD: 256 frontend_imsg_compose_main(imsg.hdr.type, 0, NULL, 0); 257 break; 258 case IMSG_CTL_LOG_VERBOSE: 259 if (IMSG_DATA_SIZE(imsg) != sizeof(verbose)) 260 break; 261 262 /* Forward to all other processes. */ 263 frontend_imsg_compose_main(imsg.hdr.type, imsg.hdr.pid, 264 imsg.data, IMSG_DATA_SIZE(imsg)); 265 frontend_imsg_compose_engine(imsg.hdr.type, 266 imsg.hdr.pid, imsg.data, IMSG_DATA_SIZE(imsg)); 267 268 memcpy(&verbose, imsg.data, sizeof(verbose)); 269 log_setverbose(verbose); 270 break; 271 default: 272 log_debug("%s: error handling imsg %d", __func__, 273 imsg.hdr.type); 274 break; 275 } 276 imsg_free(&imsg); 277 } 278 279 imsg_event_add(&c->iev); 280 } 281 282 int 283 control_imsg_relay(struct imsg *imsg) 284 { 285 struct ctl_conn *c; 286 287 if ((c = control_connbypid(imsg->hdr.pid)) == NULL) 288 return (0); 289 290 return (imsg_compose_event(&c->iev, imsg->hdr.type, 0, imsg->hdr.pid, 291 -1, imsg->data, IMSG_DATA_SIZE(*imsg))); 292 } 293