1 /* $OpenBSD: control.c,v 1.15 2023/03/08 04:43:13 guenther 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 close(connfd); 163 log_warn("%s: calloc", __func__); 164 return; 165 } 166 167 imsg_init(&c->iev.ibuf, connfd); 168 c->iev.handler = control_dispatch_imsg; 169 c->iev.events = EV_READ; 170 c->iev.data = cs; /* proc.c cheats (reuses the handler) */ 171 event_set(&c->iev.ev, c->iev.ibuf.fd, c->iev.events, 172 c->iev.handler, cs); 173 event_add(&c->iev.ev, NULL); 174 175 TAILQ_INSERT_TAIL(&ctl_conns, c, entry); 176 } 177 178 struct ctl_conn * 179 control_connbyfd(int fd) 180 { 181 struct ctl_conn *c; 182 183 TAILQ_FOREACH(c, &ctl_conns, entry) { 184 if (c->iev.ibuf.fd == fd) 185 break; 186 } 187 188 return (c); 189 } 190 191 void 192 control_close(int fd, struct control_sock *cs) 193 { 194 struct ctl_conn *c; 195 196 if ((c = control_connbyfd(fd)) == NULL) { 197 log_warn("%s: fd %d not found", __func__, fd); 198 return; 199 } 200 201 msgbuf_clear(&c->iev.ibuf.w); 202 TAILQ_REMOVE(&ctl_conns, c, entry); 203 204 event_del(&c->iev.ev); 205 close(c->iev.ibuf.fd); 206 207 /* Some file descriptors are available again. */ 208 if (evtimer_pending(&cs->cs_evt, NULL)) { 209 evtimer_del(&cs->cs_evt); 210 event_add(&cs->cs_ev, NULL); 211 } 212 213 free(c); 214 } 215 216 void 217 control_dispatch_imsg(int fd, short event, void *arg) 218 { 219 struct control_sock *cs = arg; 220 struct ctl_conn *c; 221 struct imsg imsg; 222 int n; 223 int verbose; 224 struct httpd *env = cs->cs_env; 225 226 if ((c = control_connbyfd(fd)) == NULL) { 227 log_warn("%s: fd %d not found", __func__, fd); 228 return; 229 } 230 231 if (event & EV_READ) { 232 if (((n = imsg_read(&c->iev.ibuf)) == -1 && errno != EAGAIN) || 233 n == 0) { 234 control_close(fd, cs); 235 return; 236 } 237 } 238 239 if (event & EV_WRITE) { 240 if (msgbuf_write(&c->iev.ibuf.w) <= 0 && errno != EAGAIN) { 241 control_close(fd, cs); 242 return; 243 } 244 } 245 246 for (;;) { 247 if ((n = imsg_get(&c->iev.ibuf, &imsg)) == -1) { 248 control_close(fd, cs); 249 return; 250 } 251 252 if (n == 0) 253 break; 254 255 if (c->waiting) { 256 log_debug("%s: unexpected imsg %d", 257 __func__, imsg.hdr.type); 258 imsg_free(&imsg); 259 control_close(fd, cs); 260 return; 261 } 262 263 switch (imsg.hdr.type) { 264 case IMSG_CTL_SHUTDOWN: 265 case IMSG_CTL_RELOAD: 266 case IMSG_CTL_REOPEN: 267 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 268 break; 269 case IMSG_CTL_NOTIFY: 270 if (c->flags & CTL_CONN_NOTIFY) { 271 log_debug("%s: " 272 "client requested notify more than once", 273 __func__); 274 imsg_compose_event(&c->iev, IMSG_CTL_FAIL, 275 0, env->sc_ps->ps_instance + 1, -1, 276 NULL, 0); 277 break; 278 } 279 c->flags |= CTL_CONN_NOTIFY; 280 break; 281 case IMSG_CTL_VERBOSE: 282 IMSG_SIZE_CHECK(&imsg, &verbose); 283 284 memcpy(&verbose, imsg.data, sizeof(verbose)); 285 286 proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT, -1); 287 proc_forward_imsg(env->sc_ps, &imsg, PROC_SERVER, -1); 288 289 memcpy(imsg.data, &verbose, sizeof(verbose)); 290 control_imsg_forward(env->sc_ps, &imsg); 291 log_setverbose(verbose); 292 break; 293 default: 294 log_debug("%s: error handling imsg %d", 295 __func__, imsg.hdr.type); 296 break; 297 } 298 imsg_free(&imsg); 299 } 300 301 imsg_event_add(&c->iev); 302 } 303 304 void 305 control_imsg_forward(struct privsep *ps, struct imsg *imsg) 306 { 307 struct ctl_conn *c; 308 309 TAILQ_FOREACH(c, &ctl_conns, entry) 310 if (c->flags & CTL_CONN_NOTIFY) 311 imsg_compose_event(&c->iev, imsg->hdr.type, 312 0, ps->ps_instance + 1, -1, imsg->data, 313 imsg->hdr.len - IMSG_HEADER_SIZE); 314 } 315