| 1 | /* |
| 2 | ashd - A Sane HTTP Daemon |
| 3 | Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com> |
| 4 | |
| 5 | This program is free software: you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <stdio.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <unistd.h> |
| 23 | #include <string.h> |
| 24 | #include <time.h> |
| 25 | #include <errno.h> |
| 26 | #include <sys/select.h> |
| 27 | #include <sys/socket.h> |
| 28 | |
| 29 | #ifdef HAVE_CONFIG_H |
| 30 | #include <config.h> |
| 31 | #endif |
| 32 | #include <log.h> |
| 33 | #include <utils.h> |
| 34 | #include <mt.h> |
| 35 | #include <mtio.h> |
| 36 | |
| 37 | static struct blocker *blockers; |
| 38 | |
| 39 | #ifdef HAVE_EPOLL |
| 40 | |
| 41 | /* |
| 42 | * Support for epoll. Optimally, different I/O loops should be split |
| 43 | * into different files for greater clarity, but I'll save that fun |
| 44 | * for another day. |
| 45 | * |
| 46 | * Scroll down to #else for the normal select loop. |
| 47 | */ |
| 48 | |
| 49 | #include <sys/epoll.h> |
| 50 | |
| 51 | struct blocker { |
| 52 | struct blocker *n, *p, *n2, *p2; |
| 53 | int fd, reg; |
| 54 | int ev; |
| 55 | time_t to; |
| 56 | struct muth *th; |
| 57 | }; |
| 58 | |
| 59 | static int epfd = -1, fdln = 0; |
| 60 | static struct blocker **fdlist; |
| 61 | |
| 62 | static int regfd(struct blocker *bl) |
| 63 | { |
| 64 | struct blocker *o; |
| 65 | struct epoll_event evd; |
| 66 | |
| 67 | memset(&evd, 0, sizeof(evd)); |
| 68 | evd.events = 0; |
| 69 | if(bl->ev & EV_READ) |
| 70 | evd.events |= EPOLLIN; |
| 71 | if(bl->ev & EV_WRITE) |
| 72 | evd.events |= EPOLLOUT; |
| 73 | evd.data.fd = bl->fd; |
| 74 | if(bl->fd >= fdln) { |
| 75 | if(fdlist) { |
| 76 | fdlist = srealloc(fdlist, sizeof(*fdlist) * (bl->fd + 1)); |
| 77 | memset(fdlist + fdln, 0, sizeof(*fdlist) * (bl->fd + 1 - fdln)); |
| 78 | fdln = bl->fd + 1; |
| 79 | } else { |
| 80 | fdlist = szmalloc(sizeof(*fdlist) * (fdln = (bl->fd + 1))); |
| 81 | } |
| 82 | } |
| 83 | if(fdlist[bl->fd] == NULL) { |
| 84 | if(epoll_ctl(epfd, EPOLL_CTL_ADD, bl->fd, &evd)) { |
| 85 | /* XXX?! Whatever to do, really? */ |
| 86 | flog(LOG_ERR, "epoll_add on fd %i: %s", bl->fd, strerror(errno)); |
| 87 | return(-1); |
| 88 | } |
| 89 | } else { |
| 90 | for(o = fdlist[bl->fd]; o; o = o->n2) { |
| 91 | if(o->ev & EV_READ) |
| 92 | evd.events |= EPOLLIN; |
| 93 | if(o->ev & EV_WRITE) |
| 94 | evd.events |= EPOLLOUT; |
| 95 | } |
| 96 | if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) { |
| 97 | /* XXX?! Whatever to do, really? */ |
| 98 | flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno)); |
| 99 | return(-1); |
| 100 | } |
| 101 | } |
| 102 | bl->n2 = fdlist[bl->fd]; |
| 103 | bl->p2 = NULL; |
| 104 | if(fdlist[bl->fd] != NULL) |
| 105 | fdlist[bl->fd]->p2 = bl; |
| 106 | fdlist[bl->fd] = bl; |
| 107 | bl->reg = 1; |
| 108 | return(0); |
| 109 | } |
| 110 | |
| 111 | static void remfd(struct blocker *bl) |
| 112 | { |
| 113 | struct blocker *o; |
| 114 | struct epoll_event evd; |
| 115 | |
| 116 | if(!bl->reg) |
| 117 | return; |
| 118 | if(bl->n2) |
| 119 | bl->n2->p2 = bl->p2; |
| 120 | if(bl->p2) |
| 121 | bl->p2->n2 = bl->n2; |
| 122 | if(bl == fdlist[bl->fd]) |
| 123 | fdlist[bl->fd] = bl->n2; |
| 124 | if(fdlist[bl->fd] == NULL) { |
| 125 | if(epoll_ctl(epfd, EPOLL_CTL_DEL, bl->fd, NULL)) |
| 126 | flog(LOG_ERR, "epoll_del on fd %i: %s", bl->fd, strerror(errno)); |
| 127 | } else { |
| 128 | memset(&evd, 0, sizeof(evd)); |
| 129 | evd.events = 0; |
| 130 | evd.data.fd = bl->fd; |
| 131 | for(o = fdlist[bl->fd]; o; o = o->n2) { |
| 132 | if(o->ev & EV_READ) |
| 133 | evd.events |= EPOLLIN; |
| 134 | if(o->ev & EV_WRITE) |
| 135 | evd.events |= EPOLLOUT; |
| 136 | } |
| 137 | if(epoll_ctl(epfd, EPOLL_CTL_MOD, bl->fd, &evd)) { |
| 138 | /* XXX?! Whatever to do, really? */ |
| 139 | flog(LOG_ERR, "epoll_mod on fd %i: %s", bl->fd, strerror(errno)); |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | |
| 144 | int block(int fd, int ev, time_t to) |
| 145 | { |
| 146 | struct blocker *bl; |
| 147 | int rv; |
| 148 | |
| 149 | omalloc(bl); |
| 150 | bl->fd = fd; |
| 151 | bl->ev = ev; |
| 152 | if(to > 0) |
| 153 | bl->to = time(NULL) + to; |
| 154 | bl->th = current; |
| 155 | if((epfd >= 0) && regfd(bl)) { |
| 156 | free(bl); |
| 157 | return(-1); |
| 158 | } |
| 159 | bl->n = blockers; |
| 160 | if(blockers) |
| 161 | blockers->p = bl; |
| 162 | blockers = bl; |
| 163 | rv = yield(); |
| 164 | if(bl->n) |
| 165 | bl->n->p = bl->p; |
| 166 | if(bl->p) |
| 167 | bl->p->n = bl->n; |
| 168 | if(bl == blockers) |
| 169 | blockers = bl->n; |
| 170 | remfd(bl); |
| 171 | free(bl); |
| 172 | return(rv); |
| 173 | } |
| 174 | |
| 175 | void ioloop(void) |
| 176 | { |
| 177 | struct blocker *bl, *nbl; |
| 178 | struct epoll_event evr[16]; |
| 179 | int i, fd, nev, ev, toval; |
| 180 | time_t now, timeout; |
| 181 | |
| 182 | epfd = epoll_create(128); |
| 183 | for(bl = blockers; bl; bl = nbl) { |
| 184 | nbl = bl->n; |
| 185 | if(regfd(bl)) |
| 186 | resume(bl->th, -1); |
| 187 | } |
| 188 | while(blockers != NULL) { |
| 189 | timeout = 0; |
| 190 | for(bl = blockers; bl; bl = bl->n) { |
| 191 | if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to))) |
| 192 | timeout = bl->to; |
| 193 | } |
| 194 | now = time(NULL); |
| 195 | if(timeout == 0) |
| 196 | toval = -1; |
| 197 | else if(timeout > now) |
| 198 | toval = (timeout - now) * 1000; |
| 199 | else |
| 200 | toval = 1000; |
| 201 | nev = epoll_wait(epfd, evr, sizeof(evr) / sizeof(*evr), toval); |
| 202 | if(nev < 0) { |
| 203 | if(errno != EINTR) { |
| 204 | flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno)); |
| 205 | /* To avoid CPU hogging in case it's bad, which it |
| 206 | * probably is. */ |
| 207 | sleep(1); |
| 208 | } |
| 209 | continue; |
| 210 | } |
| 211 | for(i = 0; i < nev; i++) { |
| 212 | fd = evr[i].data.fd; |
| 213 | ev = 0; |
| 214 | if(evr[i].events & EPOLLIN) |
| 215 | ev |= EV_READ; |
| 216 | if(evr[i].events & EPOLLOUT) |
| 217 | ev |= EV_WRITE; |
| 218 | if(evr[i].events & ~(EPOLLIN | EPOLLOUT)) |
| 219 | ev = -1; |
| 220 | for(bl = fdlist[fd]; bl; bl = nbl) { |
| 221 | nbl = bl->n2; |
| 222 | if((ev < 0) || (ev & bl->ev)) |
| 223 | resume(bl->th, ev); |
| 224 | } |
| 225 | } |
| 226 | now = time(NULL); |
| 227 | for(bl = blockers; bl; bl = nbl) { |
| 228 | nbl = bl->n; |
| 229 | if((bl->to != 0) && (bl->to <= now)) |
| 230 | resume(bl->th, 0); |
| 231 | } |
| 232 | } |
| 233 | close(epfd); |
| 234 | epfd = -1; |
| 235 | } |
| 236 | |
| 237 | #else |
| 238 | |
| 239 | struct blocker { |
| 240 | struct blocker *n, *p; |
| 241 | int fd; |
| 242 | int ev; |
| 243 | time_t to; |
| 244 | struct muth *th; |
| 245 | }; |
| 246 | |
| 247 | int block(int fd, int ev, time_t to) |
| 248 | { |
| 249 | struct blocker *bl; |
| 250 | int rv; |
| 251 | |
| 252 | omalloc(bl); |
| 253 | bl->fd = fd; |
| 254 | bl->ev = ev; |
| 255 | if(to > 0) |
| 256 | bl->to = time(NULL) + to; |
| 257 | bl->th = current; |
| 258 | bl->n = blockers; |
| 259 | if(blockers) |
| 260 | blockers->p = bl; |
| 261 | blockers = bl; |
| 262 | rv = yield(); |
| 263 | if(bl->n) |
| 264 | bl->n->p = bl->p; |
| 265 | if(bl->p) |
| 266 | bl->p->n = bl->n; |
| 267 | if(bl == blockers) |
| 268 | blockers = bl->n; |
| 269 | free(bl); |
| 270 | return(rv); |
| 271 | } |
| 272 | |
| 273 | void ioloop(void) |
| 274 | { |
| 275 | int ret; |
| 276 | fd_set rfds, wfds, efds; |
| 277 | struct blocker *bl, *nbl; |
| 278 | struct timeval toval; |
| 279 | time_t now, timeout; |
| 280 | int maxfd; |
| 281 | int ev; |
| 282 | |
| 283 | while(blockers != NULL) { |
| 284 | FD_ZERO(&rfds); |
| 285 | FD_ZERO(&wfds); |
| 286 | FD_ZERO(&efds); |
| 287 | maxfd = 0; |
| 288 | now = time(NULL); |
| 289 | timeout = 0; |
| 290 | for(bl = blockers; bl; bl = bl->n) { |
| 291 | if(bl->ev & EV_READ) |
| 292 | FD_SET(bl->fd, &rfds); |
| 293 | if(bl->ev & EV_WRITE) |
| 294 | FD_SET(bl->fd, &wfds); |
| 295 | FD_SET(bl->fd, &efds); |
| 296 | if(bl->fd > maxfd) |
| 297 | maxfd = bl->fd; |
| 298 | if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to))) |
| 299 | timeout = bl->to; |
| 300 | } |
| 301 | toval.tv_sec = timeout - now; |
| 302 | toval.tv_usec = 0; |
| 303 | ret = select(maxfd + 1, &rfds, &wfds, &efds, timeout?(&toval):NULL); |
| 304 | if(ret < 0) { |
| 305 | if(errno != EINTR) { |
| 306 | flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno)); |
| 307 | /* To avoid CPU hogging in case it's bad, which it |
| 308 | * probably is. */ |
| 309 | sleep(1); |
| 310 | } |
| 311 | } |
| 312 | now = time(NULL); |
| 313 | for(bl = blockers; bl; bl = nbl) { |
| 314 | nbl = bl->n; |
| 315 | ev = 0; |
| 316 | if(FD_ISSET(bl->fd, &rfds)) |
| 317 | ev |= EV_READ; |
| 318 | if(FD_ISSET(bl->fd, &wfds)) |
| 319 | ev |= EV_WRITE; |
| 320 | if(FD_ISSET(bl->fd, &efds)) |
| 321 | ev = -1; |
| 322 | if((ev < 0) || (ev & bl->ev)) |
| 323 | resume(bl->th, ev); |
| 324 | else if((bl->to != 0) && (bl->to <= now)) |
| 325 | resume(bl->th, 0); |
| 326 | } |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | #endif |
| 331 | |
| 332 | struct stdiofd { |
| 333 | int fd; |
| 334 | int sock; |
| 335 | int timeout; |
| 336 | }; |
| 337 | |
| 338 | static ssize_t mtread(void *cookie, char *buf, size_t len) |
| 339 | { |
| 340 | struct stdiofd *d = cookie; |
| 341 | int ev; |
| 342 | ssize_t ret; |
| 343 | |
| 344 | while(1) { |
| 345 | ret = read(d->fd, buf, len); |
| 346 | if((ret < 0) && (errno == EAGAIN)) { |
| 347 | ev = block(d->fd, EV_READ, d->timeout); |
| 348 | if(ev < 0) { |
| 349 | /* If we just go on, we should get the real error. */ |
| 350 | continue; |
| 351 | } else if(ev == 0) { |
| 352 | errno = ETIMEDOUT; |
| 353 | return(-1); |
| 354 | } else { |
| 355 | continue; |
| 356 | } |
| 357 | } else { |
| 358 | return(ret); |
| 359 | } |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | static ssize_t mtwrite(void *cookie, const char *buf, size_t len) |
| 364 | { |
| 365 | struct stdiofd *d = cookie; |
| 366 | int ev; |
| 367 | size_t off; |
| 368 | ssize_t ret; |
| 369 | |
| 370 | off = 0; |
| 371 | while(off < len) { |
| 372 | if(d->sock) |
| 373 | ret = send(d->fd, buf + off, len - off, MSG_DONTWAIT | MSG_NOSIGNAL); |
| 374 | else |
| 375 | ret = write(d->fd, buf + off, len - off); |
| 376 | if(ret < 0) { |
| 377 | if(errno == EAGAIN) { |
| 378 | ev = block(d->fd, EV_WRITE, d->timeout); |
| 379 | if(ev < 0) { |
| 380 | /* If we just go on, we should get the real error. */ |
| 381 | continue; |
| 382 | } else if(ev == 0) { |
| 383 | errno = ETIMEDOUT; |
| 384 | return(off); |
| 385 | } else { |
| 386 | continue; |
| 387 | } |
| 388 | } else { |
| 389 | return(off); |
| 390 | } |
| 391 | } else { |
| 392 | off += ret; |
| 393 | } |
| 394 | } |
| 395 | return(off); |
| 396 | } |
| 397 | |
| 398 | static int mtclose(void *cookie) |
| 399 | { |
| 400 | struct stdiofd *d = cookie; |
| 401 | |
| 402 | close(d->fd); |
| 403 | free(d); |
| 404 | return(0); |
| 405 | } |
| 406 | |
| 407 | static cookie_io_functions_t iofuns = { |
| 408 | .read = mtread, |
| 409 | .write = mtwrite, |
| 410 | .close = mtclose, |
| 411 | }; |
| 412 | |
| 413 | FILE *mtstdopen(int fd, int issock, int timeout, char *mode) |
| 414 | { |
| 415 | struct stdiofd *d; |
| 416 | FILE *ret; |
| 417 | |
| 418 | omalloc(d); |
| 419 | d->fd = fd; |
| 420 | d->sock = issock; |
| 421 | d->timeout = timeout; |
| 422 | ret = fopencookie(d, mode, iofuns); |
| 423 | if(!ret) |
| 424 | free(d); |
| 425 | else |
| 426 | fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK); |
| 427 | return(ret); |
| 428 | } |