1 /* $OpenBSD: control.c,v 1.21 2024/11/21 13:38:45 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/queue.h> 20 #include <sys/stat.h> 21 #include <sys/socket.h> 22 #include <sys/time.h> 23 #include <sys/un.h> 24 25 #include <errno.h> 26 #include <event.h> 27 #include <fcntl.h> 28 #include <stdlib.h> 29 #include <string.h> 30 #include <unistd.h> 31 #include <imsg.h> 32 33 #include "httpd.h" 34 35 #define CONTROL_BACKLOG 5 36 37 struct ctl_connlist ctl_conns = TAILQ_HEAD_INITIALIZER(ctl_conns); 38 39 void control_accept(int, short, void *); 40 void control_close(int, struct control_sock *); 41 42 int 43 control_init(struct privsep *ps, struct control_sock *cs) 44 { 45 struct httpd *env = ps->ps_env; 46 struct sockaddr_un sun; 47 int fd; 48 mode_t old_umask, mode; 49 50 if (cs->cs_name == NULL) 51 return (0); 52 53 if ((fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0)) == -1) { 54 log_warn("%s: socket", __func__); 55 return (-1); 56 } 57 58 sun.sun_family = AF_UNIX; 59 if (strlcpy(sun.sun_path, cs->cs_name, 60 sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) { 61 log_warn("%s: %s name too long", __func__, cs->cs_name); 62 close(fd); 63 return (-1); 64 } 65 66 if (unlink(cs->cs_name) == -1) 67 if (errno != ENOENT) { 68 log_warn("%s: unlink %s", __func__, cs->cs_name); 69 close(fd); 70 return (-1); 71 } 72 73 if (cs->cs_restricted) { 74 old_umask = umask(S_IXUSR|S_IXGRP|S_IXOTH); 75 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH; 76 } else { 77 old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH); 78 mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP; 79 } 80 81 if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) { 82 log_warn("%s: bind: %s", __func__, cs->cs_name); 83 close(fd); 84 (void)umask(old_umask); 85 return (-1); 86 } 87 (void)umask(old_umask); 88 89 if (chmod(cs->cs_name, mode) == -1) { 90 log_warn("%s: chmod", __func__); 91 close(fd); 92 (void)unlink(cs->cs_name); 93 return (-1); 94 } 95 96 cs->cs_fd = fd; 97 cs->cs_env = env; 98 99 return (0); 100 } 101 102 int 103 control_listen(struct control_sock *cs) 104 { 105 if (cs->cs_name == NULL) 106 return (0); 107 108 if (listen(cs->cs_fd, CONTROL_BACKLOG) == -1) { 109 log_warn("%s: listen", __func__); 110 return (-1); 111 } 112 113 event_set(&cs->cs_ev, cs->cs_fd, EV_READ, 114 control_accept, cs); 115 event_add(&cs->cs_ev, NULL); 116 evtimer_set(&cs->cs_evt, control_accept, cs); 117 118 return (0); 119 } 120 121 void 122 control_cleanup(struct control_sock *cs) 123 { 124 if (cs->cs_name == NULL) 125 return; 126 event_del(&cs->cs_ev); 127 event_del(&cs->cs_evt); 128 } 129 130 void 131 control_accept(int listenfd, short event, void *arg) 132 { 133 int connfd; 134 socklen_t len; 135 struct sockaddr_un sun; 136 struct ctl_conn *c; 137 struct control_sock *cs = arg; 138 139 event_add(&cs->cs_ev, NULL); 140 if ((event & EV_TIMEOUT)) 141 return; 142 143 len = sizeof(sun); 144 if ((connfd = accept4(listenfd, 145 (struct sockaddr *)&sun, &len, SOCK_NONBLOCK)) == -1) { 146 /* 147 * Pause accept if we are out of file descriptors, or 148 * libevent will haunt us here too. 149 */ 150 if (errno == ENFILE || errno == EMFILE) { 151 struct timeval evtpause = { 1, 0 }; 152 153 event_del(&cs->cs_ev); 154 evtimer_add(&cs->cs_evt, &evtpause); 155 } else if (errno != EWOULDBLOCK && errno != EINTR && 156 errno != ECONNABORTED) 157 log_warn("%s: accept", __func__); 158 return; 159 } 160 161 if ((c = calloc(1, sizeof(struct ctl_conn))) == NULL) { 162 log_warn("%s: calloc", __func__); 163 close(connfd); 164 return; 165 } 166 167 if (imsgbuf_init(&c->iev.ibuf, connfd) == -1) { 168 log_warn("%s: imsgbuf_init", __func__); 169 close(connfd); 170 free(c); 171 return; 172 } 173 c->iev.handler = control_dispatch_imsg; 174 c->iev.events = EV_READ; 175 c->iev.data = cs; /* proc.c cheats (reuses the handler) */ 176 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 177 c->iev.handler, cs); 178 event_add(&c->iev.ev, NULL); 179 180 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 181 } 182 183 struct ctl_conn * 184 control_connbyfd(int fd) 185 { 186 struct ctl_conn *c; 187 188 TAILQ_FOREACH(c, &ctl_conns, entry) { 189 if (c->iev.ibuf.fd == fd) 190 break; 191 } 192 193 return (c); 194 } 195 196 void 197 control_close(int fd, struct control_sock *cs) 198 { 199 struct ctl_conn *c; 200 201 if ((c = control_connbyfd(fd)) == NULL) { 202 log_warn("%s: fd %d not found", __func__, fd); 203 return; 204 } 205 206 imsgbuf_clear(&c->iev.ibuf); 207 TAILQ_REMOVE(&ctl_conns, c, entry); 208 209 event_del(&c->iev.ev); 210 close(c->iev.ibuf.fd); 211 212 /* Some file descriptors are available again. */ 213 if (evtimer_pending(&cs->cs_evt, NULL)) { 214 evtimer_del(&cs->cs_evt); 215 event_add(&cs->cs_ev, NULL); 216 } 217 218 free(c); 219 } 220 221 void 222 control_dispatch_imsg(int fd, short event, void *arg) 223 { 224 struct control_sock *cs = arg; 225 struct ctl_conn *c; 226 struct imsg imsg; 227 int n; 228 int verbose; 229 struct httpd *env = cs->cs_env; 230 231 if ((c = control_connbyfd(fd)) == NULL) { 232 log_warn("%s: fd %d not found", __func__, fd); 233 return; 234 } 235 236 if (event & EV_READ) { 237 if (imsgbuf_read(&c->iev.ibuf) != 1) { 238 control_close(fd, cs); 239 return; 240 } 241 } 242 243 if (event & EV_WRITE) { 244 if (imsgbuf_write(&c->iev.ibuf) == -1) { 245 control_close(fd, cs); 246 return; 247 } 248 } 249 250 for (;;) { 251 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 252 control_close(fd, cs); 253 return; 254 } 255 256 if (n == 0) 257 break; 258 259 if (c->waiting) { 260 log_debug("%s: unexpected imsg %d", 261 __func__, imsg.hdr.type); 262 imsg_free(&imsg); 263 control_close(fd, cs); 264 return; 265 } 266 267 switch (imsg.hdr.type) { 268 case IMSG_CTL_SHUTDOWN: 269 case IMSG_CTL_RELOAD: 270 case IMSG_CTL_REOPEN: 271 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 272 break; 273 case IMSG_CTL_NOTIFY: 274 if (c->flags & CTL_CONN_NOTIFY) { 275 log_debug("%s: " 276 "client requested notify more than once", 277 __func__); 278 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 279 0, env->sc_ps->ps_instance + 1, -1, 280 NULL, 0); 281 break; 282 } 283 c->flags |= CTL_CONN_NOTIFY; 284 break; 285 case IMSG_CTL_VERBOSE: 286 IMSG_SIZE_CHECK(&imsg, &verbose); 287 288 memcpy(&verbose, imsg.data, sizeof(verbose)); 289 290 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 291 proc_forward_imsg(env->sc_ps, &imsg, PROC_SERVER, -1); 292 293 memcpy(imsg.data, &verbose, sizeof(verbose)); 294 control_imsg_forward(env->sc_ps, &imsg); 295 log_setverbose(verbose); 296 break; 297 default: 298 log_debug("%s: error handling imsg %d", 299 __func__, imsg.hdr.type); 300 break; 301 } 302 imsg_free(&imsg); 303 } 304 305 imsg_event_add(&c->iev); 306 } 307 308 void 309 control_imsg_forward(struct privsep *ps, struct imsg *imsg) 310 { 311 struct ctl_conn *c; 312 313 TAILQ_FOREACH(c, &ctl_conns, entry) 314 if (c->flags & CTL_CONN_NOTIFY) 315 imsg_compose_event(&c->iev, imsg->hdr.type, 316 0, ps->ps_instance + 1, -1, imsg->data, 317 imsg->hdr.len - IMSG_HEADER_SIZE); 318 } 319