| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Main daemon |
| 4 | * |
| 5 | * (c) 2012 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Yet Another Ident Daemon (YAID). |
| 11 | * |
| 12 | * YAID is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU General Public License as published by |
| 14 | * the Free Software Foundation; either version 2 of the License, or |
| 15 | * (at your option) any later version. |
| 16 | * |
| 17 | * YAID is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with YAID; if not, write to the Free Software Foundation, |
| 24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 25 | */ |
| 26 | |
| 27 | /*----- Header files ------------------------------------------------------*/ |
| 28 | |
| 29 | #include "yaid.h" |
| 30 | |
| 31 | /*----- Data structures ---------------------------------------------------*/ |
| 32 | |
| 33 | /* A write buffer is the gadget which keeps track of our output and writes |
| 34 | * portions of it out as and when connections are ready for it. |
| 35 | */ |
| 36 | #define WRBUFSZ 1024 |
| 37 | struct writebuf { |
| 38 | size_t o; /* Offset of remaining data */ |
| 39 | size_t n; /* Length of remaining data */ |
| 40 | sel_file wr; /* Write selector */ |
| 41 | void (*func)(int /*err*/, void *); /* Function to call on completion */ |
| 42 | void *p; /* Context for `func' */ |
| 43 | unsigned char buf[WRBUFSZ]; /* Output buffer */ |
| 44 | }; |
| 45 | |
| 46 | /* Structure for a listening socket. There's one of these for each address |
| 47 | * family we're looking after. |
| 48 | */ |
| 49 | struct listen { |
| 50 | const struct addrops *ao; /* Address family operations */ |
| 51 | sel_file f; /* Watch for incoming connections */ |
| 52 | }; |
| 53 | |
| 54 | /* The main structure for a client. */ |
| 55 | struct client { |
| 56 | int fd; /* The connection to the client */ |
| 57 | selbuf b; /* Accumulate lines of input */ |
| 58 | union addr raddr; /* Remote address */ |
| 59 | struct query q; /* The clients query and our reply */ |
| 60 | struct sel_timer t; /* Timeout for idle or doomed conn */ |
| 61 | struct listen *l; /* Back to the listener (and ops) */ |
| 62 | struct writebuf wb; /* Write buffer for our reply */ |
| 63 | struct proxy *px; /* Proxy if conn goes via NAT */ |
| 64 | struct client *next; /* Next in a chain of clients */ |
| 65 | }; |
| 66 | |
| 67 | /* A proxy connection. */ |
| 68 | struct proxy { |
| 69 | int fd; /* Connection; -1 if in progress */ |
| 70 | struct client *c; /* Back to the client */ |
| 71 | conn cn; /* Nonblocking connection */ |
| 72 | selbuf b; /* Accumulate the response line */ |
| 73 | struct writebuf wb; /* Write buffer for query */ |
| 74 | char nat[ADDRLEN]; /* Server address, as text */ |
| 75 | struct proxy *next; /* Next in a chain of proxies */ |
| 76 | }; |
| 77 | |
| 78 | /*----- Static variables --------------------------------------------------*/ |
| 79 | |
| 80 | static sel_state sel; /* I/O multiplexer state */ |
| 81 | |
| 82 | static const char *pidfile = 0; /* Where to write daemon's pid */ |
| 83 | |
| 84 | static const char *policyfile = POLICYFILE; /* Filename for global policy */ |
| 85 | static const struct policy default_policy = POLICY_INIT(A_NAME); |
| 86 | static policy_v policy = DA_INIT; /* Vector of global policy rules */ |
| 87 | static fwatch polfw; /* Watch policy file for changes */ |
| 88 | |
| 89 | static unsigned char tokenbuf[4096]; /* Random-ish data for tokens */ |
| 90 | static size_t tokenptr = sizeof(tokenbuf); /* Current read position */ |
| 91 | |
| 92 | static struct client *dead_clients = 0; /* List of defunct clients */ |
| 93 | static struct proxy *dead_proxies = 0; /* List of defunct proxies */ |
| 94 | |
| 95 | static unsigned flags = 0; /* Various interesting flags */ |
| 96 | #define F_SYSLOG 1u /* Use syslog for logging */ |
| 97 | #define F_RUNNING 2u /* Running properly now */ |
| 98 | |
| 99 | /*----- Ident protocol parsing --------------------------------------------*/ |
| 100 | |
| 101 | /* Advance *PP over whitespace characters. */ |
| 102 | static void skipws(const char **pp) |
| 103 | { while (isspace((unsigned char )**pp)) (*pp)++; } |
| 104 | |
| 105 | /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP |
| 106 | * over it. |
| 107 | */ |
| 108 | static int idtoken(const char **pp, char *q, size_t n) |
| 109 | { |
| 110 | const char *p = *pp; |
| 111 | |
| 112 | skipws(&p); |
| 113 | n--; |
| 114 | for (;;) { |
| 115 | if (*p == ':' || *p <= 32 || *p >= 127) break; |
| 116 | if (!n) return (-1); |
| 117 | *q++ = *p++; |
| 118 | n--; |
| 119 | } |
| 120 | *q++ = 0; |
| 121 | *pp = p; |
| 122 | return (0); |
| 123 | } |
| 124 | |
| 125 | /* Read an unsigned decimal number from *PP, and store it in *II. Check that |
| 126 | * it's between MIN and MAX, and advance *PP over it. Return zero for |
| 127 | * success, or nonzero if something goes wrong. |
| 128 | */ |
| 129 | static int unum(const char **pp, unsigned *ii, unsigned min, unsigned max) |
| 130 | { |
| 131 | char *q; |
| 132 | unsigned long i; |
| 133 | int e; |
| 134 | |
| 135 | skipws(pp); |
| 136 | if (!isdigit((unsigned char)**pp)) return (-1); |
| 137 | e = errno; errno = 0; |
| 138 | i = strtoul(*pp, &q, 10); |
| 139 | if (errno) return (-1); |
| 140 | *pp = q; |
| 141 | errno = e; |
| 142 | if (i < min || i > max) return (-1); |
| 143 | *ii = i; |
| 144 | return (0); |
| 145 | } |
| 146 | |
| 147 | /*----- Asynchronous writing ----------------------------------------------*/ |
| 148 | |
| 149 | /* Callback for actually writing stuff from a `writebuf'. */ |
| 150 | static void write_out(int fd, unsigned mode, void *p) |
| 151 | { |
| 152 | ssize_t n; |
| 153 | struct writebuf *wb = p; |
| 154 | |
| 155 | /* Try to write something. */ |
| 156 | if ((n = write(fd, wb->buf + wb->o, wb->n)) < 0) { |
| 157 | if (errno == EAGAIN || errno == EWOULDBLOCK) return; |
| 158 | wb->n = 0; |
| 159 | sel_rmfile(&wb->wr); |
| 160 | wb->func(errno, wb->p); |
| 161 | } |
| 162 | wb->o += n; |
| 163 | wb->n -= n; |
| 164 | |
| 165 | /* If there's nothing left then restore the buffer to its empty state. */ |
| 166 | if (!wb->n) { |
| 167 | wb->o = 0; |
| 168 | sel_rmfile(&wb->wr); |
| 169 | wb->func(0, wb->p); |
| 170 | } |
| 171 | } |
| 172 | |
| 173 | /* Queue N bytes starting at P to be written. */ |
| 174 | static int queue_write(struct writebuf *wb, const void *p, size_t n) |
| 175 | { |
| 176 | /* Maybe there's nothing to actually do. */ |
| 177 | if (!n) return (0); |
| 178 | |
| 179 | /* Make sure it'll fit. */ |
| 180 | if (wb->n - wb->o + n > WRBUFSZ) return (-1); |
| 181 | |
| 182 | /* If there's anything there already, then make sure it's at the start of |
| 183 | * the available space. |
| 184 | */ |
| 185 | if (wb->o) { |
| 186 | memmove(wb->buf, wb->buf + wb->o, wb->n); |
| 187 | wb->o = 0; |
| 188 | } |
| 189 | |
| 190 | /* If there's nothing currently there, then we're not requesting write |
| 191 | * notifications, so set that up, and force an initial wake-up. |
| 192 | */ |
| 193 | if (!wb->n) { |
| 194 | sel_addfile(&wb->wr); |
| 195 | sel_force(&wb->wr); |
| 196 | } |
| 197 | |
| 198 | /* Copy the new material over. */ |
| 199 | memcpy(wb->buf + wb->n, p, n); |
| 200 | wb->n += n; |
| 201 | |
| 202 | /* Done. */ |
| 203 | return (0); |
| 204 | } |
| 205 | |
| 206 | /* Release resources allocated to WB. */ |
| 207 | static void free_writebuf(struct writebuf *wb) |
| 208 | { if (wb->n) sel_rmfile(&wb->wr); } |
| 209 | |
| 210 | /* Initialize a writebuf in *WB, writing to file descriptor FD. On |
| 211 | * completion, call FUNC, passing it P and an error indicator: either 0 for |
| 212 | * success or an `errno' value on failure. |
| 213 | */ |
| 214 | static void init_writebuf(struct writebuf *wb, |
| 215 | int fd, void (*func)(int, void *), void *p) |
| 216 | { |
| 217 | sel_initfile(&sel, &wb->wr, fd, SEL_WRITE, write_out, wb); |
| 218 | wb->func = func; |
| 219 | wb->p = p; |
| 220 | wb->n = wb->o = 0; |
| 221 | } |
| 222 | |
| 223 | /*----- General utilities -------------------------------------------------*/ |
| 224 | |
| 225 | static void vlogmsg(const struct query *q, int prio, |
| 226 | const char *msg, va_list *ap) |
| 227 | { |
| 228 | dstr d = DSTR_INIT; |
| 229 | time_t t; |
| 230 | struct tm *tm; |
| 231 | char buf[64]; |
| 232 | |
| 233 | if (q) { |
| 234 | dputsock(&d, q->ao, &q->s[L]); |
| 235 | dstr_puts(&d, " <-> "); |
| 236 | dputsock(&d, q->ao, &q->s[R]); |
| 237 | dstr_puts(&d, ": "); |
| 238 | } |
| 239 | dstr_vputf(&d, msg, ap); |
| 240 | |
| 241 | if (!(flags & F_RUNNING)) |
| 242 | moan("%s", d.buf); |
| 243 | else if (flags & F_SYSLOG) |
| 244 | syslog(prio, "%s", d.buf); |
| 245 | else { |
| 246 | t = time(0); |
| 247 | tm = localtime(&t); |
| 248 | strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S %z", tm); |
| 249 | fprintf(stderr, "%s %s: %s\n", buf, QUIS, d.buf); |
| 250 | } |
| 251 | |
| 252 | dstr_destroy(&d); |
| 253 | } |
| 254 | |
| 255 | /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO. |
| 256 | * Prefix it with a description of the query Q, if non-null. |
| 257 | */ |
| 258 | void logmsg(const struct query *q, int prio, const char *msg, ...) |
| 259 | { |
| 260 | va_list ap; |
| 261 | |
| 262 | va_start(ap, msg); |
| 263 | vlogmsg(q, prio, msg, &ap); |
| 264 | va_end(ap); |
| 265 | } |
| 266 | |
| 267 | /* Fix up a socket FD so that it won't bite us. Returns zero on success, or |
| 268 | * nonzero on error. |
| 269 | */ |
| 270 | static int fix_up_socket(int fd, const char *what) |
| 271 | { |
| 272 | int yes = 1; |
| 273 | |
| 274 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { |
| 275 | logmsg(0, LOG_ERR, "failed to set %s connection nonblocking: %s", |
| 276 | what, strerror(errno)); |
| 277 | return (-1); |
| 278 | } |
| 279 | |
| 280 | if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &yes, sizeof(yes))) { |
| 281 | logmsg(0, LOG_ERR, |
| 282 | "failed to disable `out-of-band' data on %s connection: %s", |
| 283 | what, strerror(errno)); |
| 284 | return (-1); |
| 285 | } |
| 286 | |
| 287 | return (0); |
| 288 | } |
| 289 | |
| 290 | /*----- Client output functions -------------------------------------------*/ |
| 291 | |
| 292 | static void disconnect_client(struct client *c); |
| 293 | |
| 294 | /* Notification that output has been written. If successful, re-enable the |
| 295 | * input buffer and prepare for another query. |
| 296 | */ |
| 297 | static void done_client_write(int err, void *p) |
| 298 | { |
| 299 | struct client *c = p; |
| 300 | |
| 301 | if (!err) |
| 302 | selbuf_enable(&c->b); |
| 303 | else { |
| 304 | logmsg(&c->q, LOG_ERR, "failed to send reply: %s", strerror(err)); |
| 305 | disconnect_client(c); |
| 306 | } |
| 307 | } |
| 308 | |
| 309 | /* Format the message FMT and queue it to be sent to the client. Client |
| 310 | * input will be disabled until the write completes. |
| 311 | */ |
| 312 | static void PRINTF_LIKE(2, 3) |
| 313 | write_to_client(struct client *c, const char *fmt, ...) |
| 314 | { |
| 315 | va_list ap; |
| 316 | char buf[WRBUFSZ]; |
| 317 | ssize_t n; |
| 318 | |
| 319 | va_start(ap, fmt); |
| 320 | n = vsnprintf(buf, sizeof(buf), fmt, ap); |
| 321 | if (n < 0) { |
| 322 | logmsg(&c->q, LOG_ERR, "failed to format output: %s", strerror(errno)); |
| 323 | disconnect_client(c); |
| 324 | return; |
| 325 | } else if (n > sizeof(buf)) { |
| 326 | logmsg(&c->q, LOG_ERR, "output too long for client send buffer"); |
| 327 | disconnect_client(c); |
| 328 | return; |
| 329 | } |
| 330 | |
| 331 | selbuf_disable(&c->b); |
| 332 | if (queue_write(&c->wb, buf, n)) { |
| 333 | logmsg(&c->q, LOG_ERR, "write buffer overflow"); |
| 334 | disconnect_client(c); |
| 335 | } |
| 336 | } |
| 337 | |
| 338 | /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1]. |
| 339 | * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will |
| 340 | * be the error token and TOK1 will be null; in the latter case, TOK0 will be |
| 341 | * the operating system and TOK1 the user name. |
| 342 | */ |
| 343 | static void reply(struct client *c, const char *ty, |
| 344 | const char *tok0, const char *tok1) |
| 345 | { |
| 346 | write_to_client(c, "%u,%u:%s:%s%s%s\r\n", |
| 347 | c->q.s[L].port, c->q.s[R].port, ty, |
| 348 | tok0, tok1 ? ":" : "", tok1 ? tok1 : ""); |
| 349 | } |
| 350 | |
| 351 | /* Mapping from error codes to their protocol tokens. */ |
| 352 | const char *const errtok[] = { |
| 353 | #define DEFTOK(err, tok) tok, |
| 354 | ERROR(DEFTOK) |
| 355 | #undef DEFTOK |
| 356 | }; |
| 357 | |
| 358 | /* Report an error with code ERR to the client. */ |
| 359 | static void reply_error(struct client *c, unsigned err) |
| 360 | { |
| 361 | assert(err < E_LIMIT); |
| 362 | reply(c, "ERROR", errtok[err], 0); |
| 363 | } |
| 364 | |
| 365 | /*----- NAT proxy functions -----------------------------------------------*/ |
| 366 | |
| 367 | /* Cancel the proxy operation PX, closing the connection and releasing |
| 368 | * resources. This is used for both normal and unexpected closures. |
| 369 | */ |
| 370 | static void cancel_proxy(struct proxy *px) |
| 371 | { |
| 372 | if (px->fd == -1) |
| 373 | conn_kill(&px->cn); |
| 374 | else { |
| 375 | close(px->fd); |
| 376 | selbuf_disable(&px->b); |
| 377 | } |
| 378 | px->c->px = 0; |
| 379 | selbuf_enable(&px->c->b); |
| 380 | px->next = dead_proxies; |
| 381 | dead_proxies = px; |
| 382 | } |
| 383 | |
| 384 | /* Delayed destruction of unsafe parts of proxies. */ |
| 385 | static void reap_dead_proxies(void) |
| 386 | { |
| 387 | struct proxy *px, *pp; |
| 388 | |
| 389 | for (px = dead_proxies; px; px = pp) { |
| 390 | pp = px->next; |
| 391 | if (px->fd != -1) { |
| 392 | selbuf_destroy(&px->b); |
| 393 | free_writebuf(&px->wb); |
| 394 | } |
| 395 | xfree(px); |
| 396 | } |
| 397 | dead_proxies = 0; |
| 398 | } |
| 399 | |
| 400 | /* Notification that a line (presumably a reply) has been received from the |
| 401 | * server. We should check it, log it, and propagate the answer back. |
| 402 | * Whatever happens, this proxy operation is now complete. |
| 403 | */ |
| 404 | static void proxy_line(char *line, size_t sz, void *p) |
| 405 | { |
| 406 | struct proxy *px = p; |
| 407 | char buf[1024]; |
| 408 | const char *q = line; |
| 409 | unsigned lp, rp; |
| 410 | |
| 411 | /* Trim trailing space. */ |
| 412 | while (sz && isspace((unsigned char)line[sz - 1])) sz--; |
| 413 | |
| 414 | /* Parse the port numbers. These should match the request. */ |
| 415 | if (unum(&q, &lp, 1, 65535)) goto syntax; |
| 416 | skipws(&q); if (*q != ',') goto syntax; q++; |
| 417 | if (unum(&q, &rp, 1, 65535)) goto syntax; |
| 418 | skipws(&q); if (*q != ':') goto syntax; q++; |
| 419 | if (lp != px->c->q.u.nat.port || rp != px->c->q.s[R].port) goto syntax; |
| 420 | |
| 421 | /* Find out what kind of reply this is. */ |
| 422 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
| 423 | skipws(&q); if (*q != ':') goto syntax; q++; |
| 424 | |
| 425 | if (strcmp(buf, "ERROR") == 0) { |
| 426 | |
| 427 | /* Report the error without interpreting it. It might be meaningful to |
| 428 | * the client. |
| 429 | */ |
| 430 | skipws(&q); |
| 431 | logmsg(&px->c->q, LOG_ERR, "proxy error from %s: %s", px->nat, q); |
| 432 | reply(px->c, "ERROR", q, 0); |
| 433 | |
| 434 | } else if (strcmp(buf, "USERID") == 0) { |
| 435 | |
| 436 | /* Parse out the operating system and user name, and pass them on. */ |
| 437 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
| 438 | skipws(&q); if (*q != ':') goto syntax; q++; |
| 439 | skipws(&q); |
| 440 | logmsg(&px->c->q, LOG_ERR, "user `%s'; proxy = %s, os = %s", |
| 441 | q, px->nat, buf); |
| 442 | reply(px->c, "USERID", buf, q); |
| 443 | |
| 444 | } else |
| 445 | goto syntax; |
| 446 | goto done; |
| 447 | |
| 448 | syntax: |
| 449 | /* We didn't understand the message from the client. */ |
| 450 | logmsg(&px->c->q, LOG_ERR, "failed to parse response from %s", px->nat); |
| 451 | reply_error(px->c, E_UNKNOWN); |
| 452 | done: |
| 453 | /* All finished, no matter what. */ |
| 454 | cancel_proxy(px); |
| 455 | } |
| 456 | |
| 457 | /* Notification that we have written the query to the server. Await a |
| 458 | * response if successful. |
| 459 | */ |
| 460 | static void done_proxy_write(int err, void *p) |
| 461 | { |
| 462 | struct proxy *px = p; |
| 463 | |
| 464 | if (err) { |
| 465 | logmsg(&px->c->q, LOG_ERR, "failed to proxy query to %s: %s", |
| 466 | px->nat, strerror(errno)); |
| 467 | reply_error(px->c, E_UNKNOWN); |
| 468 | cancel_proxy(px); |
| 469 | return; |
| 470 | } |
| 471 | selbuf_enable(&px->b); |
| 472 | } |
| 473 | |
| 474 | /* Notification that the connection to the server is either established or |
| 475 | * failed. In the former case, queue the right query. |
| 476 | */ |
| 477 | static void proxy_connected(int fd, void *p) |
| 478 | { |
| 479 | struct proxy *px = p; |
| 480 | char buf[16]; |
| 481 | int n; |
| 482 | |
| 483 | /* If the connection failed then report the problem and give up. */ |
| 484 | if (fd < 0) { |
| 485 | logmsg(&px->c->q, LOG_ERR, |
| 486 | "failed to make %s proxy connection to %s: %s", |
| 487 | px->c->l->ao->name, px->nat, strerror(errno)); |
| 488 | reply_error(px->c, E_UNKNOWN); |
| 489 | cancel_proxy(px); |
| 490 | return; |
| 491 | } |
| 492 | |
| 493 | /* We're now ready to go, so set things up. */ |
| 494 | px->fd = fd; |
| 495 | selbuf_init(&px->b, &sel, fd, proxy_line, px); |
| 496 | selbuf_setsize(&px->b, 1024); |
| 497 | selbuf_disable(&px->b); |
| 498 | init_writebuf(&px->wb, fd, done_proxy_write, px); |
| 499 | |
| 500 | /* Write the query. This buffer is large enough because we've already |
| 501 | * range-checked the remote the port number and the local one came from the |
| 502 | * kernel, which we trust not to do anything stupid. |
| 503 | */ |
| 504 | n = sprintf(buf, "%u,%u\r\n", px->c->q.u.nat.port, px->c->q.s[R].port); |
| 505 | queue_write(&px->wb, buf, n); |
| 506 | } |
| 507 | |
| 508 | /* Proxy the query through to a client machine for which we're providing NAT |
| 509 | * disservice. |
| 510 | */ |
| 511 | static void proxy_query(struct client *c) |
| 512 | { |
| 513 | struct socket s; |
| 514 | struct sockaddr_storage ss; |
| 515 | size_t ssz; |
| 516 | struct proxy *px; |
| 517 | int fd; |
| 518 | |
| 519 | /* Allocate the context structure for the NAT. */ |
| 520 | px = xmalloc(sizeof(*px)); |
| 521 | |
| 522 | /* We'll use the client host's address in lots of log messages, so we may |
| 523 | * as well format it once and use it over and over. |
| 524 | */ |
| 525 | inet_ntop(c->q.ao->af, &c->q.u.nat.addr, px->nat, sizeof(px->nat)); |
| 526 | |
| 527 | /* Create the socket for the connection. */ |
| 528 | if ((fd = socket(c->q.ao->af, SOCK_STREAM, 0)) < 0) { |
| 529 | logmsg(&c->q, LOG_ERR, "failed to make %s socket for proxy: %s", |
| 530 | c->l->ao->name, strerror(errno)); |
| 531 | goto err_0; |
| 532 | } |
| 533 | if (fix_up_socket(fd, "proxy")) goto err_1; |
| 534 | |
| 535 | /* Set up the connection to the client host. The connection interface is a |
| 536 | * bit broken: if the connection completes immediately, then the callback |
| 537 | * function is called synchronously, and that might decide to shut |
| 538 | * everything down. So we must have fully initialized our context before |
| 539 | * calling `conn_init', and mustn't touch it again afterwards -- since the |
| 540 | * block may have been freed. |
| 541 | */ |
| 542 | s = c->q.u.nat; |
| 543 | s.port = 113; |
| 544 | c->l->ao->socket_to_sockaddr(&s, &ss, &ssz); |
| 545 | selbuf_disable(&c->b); |
| 546 | c->px = px; px->c = c; |
| 547 | px->fd = -1; |
| 548 | if (conn_init(&px->cn, &sel, fd, (struct sockaddr *)&ss, ssz, |
| 549 | proxy_connected, px)) { |
| 550 | logmsg(&c->q, LOG_ERR, "failed to make %s proxy connection to %s: %s", |
| 551 | c->l->ao->name, px->nat, strerror(errno)); |
| 552 | goto err_2; |
| 553 | } |
| 554 | |
| 555 | /* All ready to go. */ |
| 556 | return; |
| 557 | |
| 558 | /* Tidy up after various kinds of failures. */ |
| 559 | err_2: |
| 560 | selbuf_enable(&c->b); |
| 561 | err_1: |
| 562 | close(px->fd); |
| 563 | err_0: |
| 564 | xfree(px); |
| 565 | reply_error(c, E_UNKNOWN); |
| 566 | } |
| 567 | |
| 568 | /*----- Client connection functions ---------------------------------------*/ |
| 569 | |
| 570 | /* Disconnect a client, freeing up any associated resources. */ |
| 571 | static void disconnect_client(struct client *c) |
| 572 | { |
| 573 | selbuf_disable(&c->b); |
| 574 | close(c->fd); |
| 575 | sel_rmtimer(&c->t); |
| 576 | free_writebuf(&c->wb); |
| 577 | if (c->px) cancel_proxy(c->px); |
| 578 | c->next = dead_clients; |
| 579 | dead_clients = c; |
| 580 | } |
| 581 | |
| 582 | /* Throw away dead clients now that we've reached a safe point in the |
| 583 | * program. |
| 584 | */ |
| 585 | static void reap_dead_clients(void) |
| 586 | { |
| 587 | struct client *c, *cc; |
| 588 | for (c = dead_clients; c; c = cc) { |
| 589 | cc = c->next; |
| 590 | selbuf_destroy(&c->b); |
| 591 | xfree(c); |
| 592 | } |
| 593 | dead_clients = 0; |
| 594 | } |
| 595 | |
| 596 | /* Time out a client because it's been idle for too long. */ |
| 597 | static void timeout_client(struct timeval *tv, void *p) |
| 598 | { |
| 599 | struct client *c = p; |
| 600 | logmsg(&c->q, LOG_NOTICE, "timing out idle or stuck client"); |
| 601 | sel_addtimer(&sel, &c->t, tv, timeout_client, 0); |
| 602 | disconnect_client(c); |
| 603 | } |
| 604 | |
| 605 | /* Reset the client idle timer, as a result of activity. Set EXISTP if |
| 606 | * there is an existing timer which needs to be removed. |
| 607 | */ |
| 608 | static void reset_client_timer(struct client *c, int existp) |
| 609 | { |
| 610 | struct timeval tv; |
| 611 | |
| 612 | gettimeofday(&tv, 0); |
| 613 | tv.tv_sec += 30; |
| 614 | if (existp) sel_rmtimer(&c->t); |
| 615 | sel_addtimer(&sel, &c->t, &tv, timeout_client, c); |
| 616 | } |
| 617 | |
| 618 | /* Write a pseudorandom token into the buffer at P, which must have space for |
| 619 | * at least TOKENSZ bytes. |
| 620 | */ |
| 621 | #define TOKENRANDSZ 8 |
| 622 | #define TOKENSZ ((4*TOKENRANDSZ + 5)/3) |
| 623 | static void user_token(char *p) |
| 624 | { |
| 625 | unsigned a = 0; |
| 626 | unsigned b = 0; |
| 627 | int i; |
| 628 | static const char tokmap[64] = |
| 629 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-"; |
| 630 | |
| 631 | /* If there's not enough pseudorandom stuff lying around, then read more |
| 632 | * from the kernel. |
| 633 | */ |
| 634 | if (tokenptr + TOKENRANDSZ >= sizeof(tokenbuf)) { |
| 635 | fill_random(tokenbuf, sizeof(tokenbuf)); |
| 636 | tokenptr = 0; |
| 637 | } |
| 638 | |
| 639 | /* Now encode the bytes using a slightly tweaked base-64 encoding. Read |
| 640 | * bytes into the accumulator and write out characters while there's |
| 641 | * enough material. |
| 642 | */ |
| 643 | for (i = 0; i < TOKENRANDSZ; i++) { |
| 644 | a = (a << 8) | tokenbuf[tokenptr++]; b += 8; |
| 645 | while (b >= 6) { |
| 646 | b -= 6; |
| 647 | *p++ = tokmap[(a >> b) & 0x3f]; |
| 648 | } |
| 649 | } |
| 650 | |
| 651 | /* If there's anything left in the accumulator then flush it out. */ |
| 652 | if (b) |
| 653 | *p++ = tokmap[(a << (6 - b)) & 0x3f]; |
| 654 | |
| 655 | /* Null-terminate the token. */ |
| 656 | *p++ = 0; |
| 657 | } |
| 658 | |
| 659 | /* Notification that a line has been received from the client. Parse it, |
| 660 | * find out about the connection it's referring to, apply the relevant |
| 661 | * policy rules, and produce a response. This is where almost everything |
| 662 | * interesting happens. |
| 663 | */ |
| 664 | static void client_line(char *line, size_t len, void *p) |
| 665 | { |
| 666 | struct client *c = p; |
| 667 | const char *q; |
| 668 | struct passwd *pw = 0; |
| 669 | const struct policy *pol; |
| 670 | dstr d = DSTR_INIT; |
| 671 | struct policy upol = POLICY_INIT(A_LIMIT); |
| 672 | struct policy_file pf; |
| 673 | char buf[16]; |
| 674 | int i, t; |
| 675 | |
| 676 | /* If the connection has closed, then tidy stuff away. */ |
| 677 | c->q.s[R].addr = c->raddr; |
| 678 | c->q.s[L].port = c->q.s[R].port = 0; |
| 679 | if (!line) { |
| 680 | disconnect_client(c); |
| 681 | return; |
| 682 | } |
| 683 | |
| 684 | /* Client activity, so update the timer. */ |
| 685 | reset_client_timer(c, 1); |
| 686 | |
| 687 | /* See if the policy file has changed since we last looked. If so, try to |
| 688 | * read the new version. |
| 689 | */ |
| 690 | if (fwatch_update(&polfw, policyfile)) { |
| 691 | logmsg(0, LOG_INFO, "reload master policy file `%s'", policyfile); |
| 692 | load_policy_file(policyfile, &policy); |
| 693 | } |
| 694 | |
| 695 | /* Read the local and remote port numbers into the query structure. */ |
| 696 | q = line; |
| 697 | if (unum(&q, &c->q.s[L].port, 1, 65535)) goto bad; |
| 698 | skipws(&q); if (*q != ',') goto bad; q++; |
| 699 | if (unum(&q, &c->q.s[R].port, 1, 65535)) goto bad; |
| 700 | skipws(&q); if (*q) goto bad; |
| 701 | |
| 702 | /* Identify the connection. Act on the result. */ |
| 703 | identify(&c->q); |
| 704 | switch (c->q.resp) { |
| 705 | |
| 706 | case R_UID: |
| 707 | /* We found a user. Track down the user's password entry, because |
| 708 | * we'll want that later. Most of the processing for this case is |
| 709 | * below. |
| 710 | */ |
| 711 | if ((pw = getpwuid(c->q.u.uid)) == 0) { |
| 712 | logmsg(&c->q, LOG_ERR, "no passwd entry for user %d", c->q.u.uid); |
| 713 | reply_error(c, E_NOUSER); |
| 714 | return; |
| 715 | } |
| 716 | break; |
| 717 | |
| 718 | case R_NAT: |
| 719 | /* We've acted as a NAT for this connection. Proxy the query through |
| 720 | * to the actal client host. |
| 721 | */ |
| 722 | proxy_query(c); |
| 723 | return; |
| 724 | |
| 725 | case R_ERROR: |
| 726 | /* We failed to identify the connection for some reason. We should |
| 727 | * already have logged an error, so there's not much to do here. |
| 728 | */ |
| 729 | reply_error(c, c->q.u.error); |
| 730 | return; |
| 731 | |
| 732 | default: |
| 733 | /* Something happened that we don't understand. */ |
| 734 | abort(); |
| 735 | } |
| 736 | |
| 737 | /* Search the table of policy rules to find a match. */ |
| 738 | for (i = 0; i < DA_LEN(&policy); i++) { |
| 739 | pol = &DA(&policy)[i]; |
| 740 | if (!match_policy(pol, &c->q)) continue; |
| 741 | |
| 742 | /* If this is something simple, then apply the resulting policy rule. */ |
| 743 | if (pol->act.act != A_USER) goto match; |
| 744 | |
| 745 | /* The global policy has decided to let the user have a say, so we must |
| 746 | * parse the user file. |
| 747 | */ |
| 748 | DRESET(&d); |
| 749 | dstr_putf(&d, "%s/.yaid.policy", pw->pw_dir); |
| 750 | if (open_policy_file(&pf, d.buf, "user policy file", &c->q, OPF_NOENTOK)) |
| 751 | continue; |
| 752 | while ((t = read_policy_file(&pf)) < T_ERROR) { |
| 753 | |
| 754 | /* Give up after 100 lines or if there's an error. If the user's |
| 755 | * policy is that complicated, something's gone very wrong. Or there's |
| 756 | * too much commentary or something. |
| 757 | */ |
| 758 | if (pf.lno > 100) { |
| 759 | logmsg(&c->q, LOG_ERR, "%s:%d: user policy file too long", |
| 760 | pf.name, pf.lno); |
| 761 | break; |
| 762 | } |
| 763 | |
| 764 | /* If this was a blank line, just go around again. */ |
| 765 | if (t != T_OK) continue; |
| 766 | |
| 767 | /* If this isn't a match, go around for the next rule. */ |
| 768 | if (!match_policy(&pf.p, &c->q)) continue; |
| 769 | |
| 770 | /* Check that the user is allowed to request this action. If not, see |
| 771 | * if there's a more acceptable action later on. |
| 772 | */ |
| 773 | if (!(pol->act.u.user & (1 << pf.p.act.act))) { |
| 774 | logmsg(&c->q, LOG_ERR, |
| 775 | "%s:%d: user action forbidden by global policy", |
| 776 | pf.name, pf.lno); |
| 777 | continue; |
| 778 | } |
| 779 | |
| 780 | /* We've found a match, so grab it, close the file, and say we're |
| 781 | * done. |
| 782 | */ |
| 783 | upol = pf.p; pol = &upol; |
| 784 | init_policy(&pf.p); |
| 785 | close_policy_file(&pf); |
| 786 | DDESTROY(&d); |
| 787 | goto match; |
| 788 | } |
| 789 | close_policy_file(&pf); |
| 790 | DDESTROY(&d); |
| 791 | } |
| 792 | |
| 793 | /* No match: apply the built-in default policy. */ |
| 794 | pol = &default_policy; |
| 795 | |
| 796 | match: |
| 797 | switch (pol->act.act) { |
| 798 | |
| 799 | case A_NAME: |
| 800 | /* Report the actual user's name. */ |
| 801 | logmsg(&c->q, LOG_INFO, "user `%s' (%d)", pw->pw_name, c->q.u.uid); |
| 802 | reply(c, "USERID", "UNIX", pw->pw_name); |
| 803 | break; |
| 804 | |
| 805 | case A_TOKEN: |
| 806 | /* Report an arbitrary token which we can look up in our log file. */ |
| 807 | user_token(buf); |
| 808 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); token = %s", |
| 809 | pw->pw_name, c->q.u.uid, buf); |
| 810 | reply(c, "USERID", "OTHER", buf); |
| 811 | break; |
| 812 | |
| 813 | case A_DENY: |
| 814 | /* Deny that there's anyone there at all. */ |
| 815 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); denying", |
| 816 | pw->pw_name, c->q.u.uid); |
| 817 | break; |
| 818 | |
| 819 | case A_HIDE: |
| 820 | /* Report the user as being hidden. */ |
| 821 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); hiding", |
| 822 | pw->pw_name, c->q.u.uid); |
| 823 | reply_error(c, E_HIDDEN); |
| 824 | break; |
| 825 | |
| 826 | case A_LIE: |
| 827 | /* Tell an egregious lie about who the user is. */ |
| 828 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); lie = `%s'", |
| 829 | pw->pw_name, c->q.u.uid, pol->act.u.lie); |
| 830 | reply(c, "USERID", "UNIX", pol->act.u.lie); |
| 831 | break; |
| 832 | |
| 833 | default: |
| 834 | /* Something has gone very wrong. */ |
| 835 | abort(); |
| 836 | } |
| 837 | |
| 838 | /* All done. */ |
| 839 | free_policy(&upol); |
| 840 | return; |
| 841 | |
| 842 | bad: |
| 843 | logmsg(&c->q, LOG_ERR, "failed to parse query from client"); |
| 844 | disconnect_client(c); |
| 845 | } |
| 846 | |
| 847 | /* Notification that a new client has connected. Prepare to read a query. */ |
| 848 | static void accept_client(int fd, unsigned mode, void *p) |
| 849 | { |
| 850 | struct listen *l = p; |
| 851 | struct client *c; |
| 852 | struct sockaddr_storage ssr, ssl; |
| 853 | size_t ssz = sizeof(ssr); |
| 854 | int sk; |
| 855 | |
| 856 | /* Accept the new connection. */ |
| 857 | if ((sk = accept(fd, (struct sockaddr *)&ssr, &ssz)) < 0) { |
| 858 | if (errno != EAGAIN && errno == EWOULDBLOCK) { |
| 859 | logmsg(0, LOG_ERR, "failed to accept incoming %s connection: %s", |
| 860 | l->ao->name, strerror(errno)); |
| 861 | } |
| 862 | return; |
| 863 | } |
| 864 | if (fix_up_socket(sk, "incoming client")) { close(sk); return; } |
| 865 | |
| 866 | /* Build a client block and fill it in. */ |
| 867 | c = xmalloc(sizeof(*c)); |
| 868 | c->l = l; |
| 869 | c->q.ao = l->ao; |
| 870 | |
| 871 | /* Collect the local and remote addresses. */ |
| 872 | l->ao->sockaddr_to_addr(&ssr, &c->raddr); |
| 873 | ssz = sizeof(ssl); |
| 874 | if (getsockname(sk, (struct sockaddr *)&ssl, &ssz)) { |
| 875 | logmsg(0, LOG_ERR, |
| 876 | "failed to read local address for incoming %s connection: %s", |
| 877 | l->ao->name, strerror(errno)); |
| 878 | close(sk); |
| 879 | xfree(c); |
| 880 | return; |
| 881 | } |
| 882 | l->ao->sockaddr_to_addr(&ssl, &c->q.s[L].addr); |
| 883 | c->q.s[L].port = c->q.s[R].port = 0; |
| 884 | |
| 885 | /* Set stuff up for reading the query and sending responses. */ |
| 886 | selbuf_init(&c->b, &sel, sk, client_line, c); |
| 887 | selbuf_setsize(&c->b, 1024); |
| 888 | reset_client_timer(c, 0); |
| 889 | c->fd = sk; |
| 890 | c->px = 0; |
| 891 | init_writebuf(&c->wb, sk, done_client_write, c); |
| 892 | } |
| 893 | |
| 894 | /*----- Main code ---------------------------------------------------------*/ |
| 895 | |
| 896 | /* Set up a listening socket for the address family described by AO, |
| 897 | * listening on PORT. |
| 898 | */ |
| 899 | static int make_listening_socket(const struct addrops *ao, int port) |
| 900 | { |
| 901 | int fd; |
| 902 | int yes = 1; |
| 903 | struct socket s; |
| 904 | struct sockaddr_storage ss; |
| 905 | struct listen *l; |
| 906 | size_t ssz; |
| 907 | |
| 908 | /* Make the socket. */ |
| 909 | if ((fd = socket(ao->af, SOCK_STREAM, 0)) < 0) { |
| 910 | if (errno == EAFNOSUPPORT) return (-1); |
| 911 | die(1, "failed to create %s listening socket: %s", |
| 912 | ao->name, strerror(errno)); |
| 913 | } |
| 914 | |
| 915 | /* Build the appropriate local address. */ |
| 916 | s.addr = *ao->any; |
| 917 | s.port = port; |
| 918 | ao->socket_to_sockaddr(&s, &ss, &ssz); |
| 919 | |
| 920 | /* Perform any initialization specific to the address type. */ |
| 921 | if (ao->init_listen_socket(fd)) { |
| 922 | die(1, "failed to initialize %s listening socket: %s", |
| 923 | ao->name, strerror(errno)); |
| 924 | } |
| 925 | |
| 926 | /* Bind to the address. */ |
| 927 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)); |
| 928 | if (bind(fd, (struct sockaddr *)&ss, ssz)) { |
| 929 | die(1, "failed to bind %s listening socket: %s", |
| 930 | ao->name, strerror(errno)); |
| 931 | } |
| 932 | |
| 933 | /* Avoid unpleasant race conditions. */ |
| 934 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { |
| 935 | die(1, "failed to set %s listening socket nonblocking: %s", |
| 936 | ao->name, strerror(errno)); |
| 937 | } |
| 938 | |
| 939 | /* Prepare to listen. */ |
| 940 | if (listen(fd, 5)) |
| 941 | die(1, "failed to listen for %s: %s", ao->name, strerror(errno)); |
| 942 | |
| 943 | /* Make a record of all of this. */ |
| 944 | l = xmalloc(sizeof(*l)); |
| 945 | l->ao = ao; |
| 946 | sel_initfile(&sel, &l->f, fd, SEL_READ, accept_client, l); |
| 947 | sel_addfile(&l->f); |
| 948 | |
| 949 | /* Done. */ |
| 950 | return (0); |
| 951 | } |
| 952 | |
| 953 | /* Quit because of a fatal signal. */ |
| 954 | static void NORETURN quit(int sig, void *p) |
| 955 | { |
| 956 | const char *signame = p; |
| 957 | |
| 958 | logmsg(0, LOG_NOTICE, "shutting down on %s", signame); |
| 959 | if (pidfile) unlink(pidfile); |
| 960 | exit(0); |
| 961 | } |
| 962 | |
| 963 | /* Answer whether the string pointed to by P consists entirely of digits. */ |
| 964 | static int numericp(const char *p) |
| 965 | { |
| 966 | while (*p) |
| 967 | if (!isdigit((unsigned char)*p++)) return (0); |
| 968 | return (1); |
| 969 | } |
| 970 | |
| 971 | static void usage(FILE *fp) |
| 972 | { |
| 973 | pquis(fp, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] " |
| 974 | "[-c FILE] [-p PORT]\n"); |
| 975 | } |
| 976 | |
| 977 | static void version(FILE *fp) |
| 978 | { pquis(fp, "$, version " VERSION "\n"); } |
| 979 | |
| 980 | static void help(FILE *fp) |
| 981 | { |
| 982 | version(fp); fputc('\n', fp); |
| 983 | usage(fp); |
| 984 | fputs("\n\ |
| 985 | Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\ |
| 986 | It's just a shame none of the others do the right things.\n\ |
| 987 | \n\ |
| 988 | Options:\n\ |
| 989 | \n\ |
| 990 | -h, --help Show this help message.\n\ |
| 991 | -v, --version Show the version number.\n\ |
| 992 | -u, --usage Show a very short usage summary.\n\ |
| 993 | \n\ |
| 994 | -D, --daemon Become a daemon, running in the background.\n\ |
| 995 | -G, --group=GROUP Set group after initialization.\n\ |
| 996 | -P, --pidfile=FILE Write process id to FILE.\n\ |
| 997 | -U, --user=USER Set user after initialization.\n\ |
| 998 | -c, --config=FILE Read global policy from FILE.\n\ |
| 999 | -l, --syslog Write log messages using syslog(3).\n\ |
| 1000 | -p, --port=PORT Listen for connections on this port.\n", |
| 1001 | fp); |
| 1002 | } |
| 1003 | |
| 1004 | int main(int argc, char *argv[]) |
| 1005 | { |
| 1006 | int port = 113; |
| 1007 | uid_t u = -1; |
| 1008 | gid_t g = -1; |
| 1009 | struct passwd *pw = 0; |
| 1010 | struct group *gr; |
| 1011 | struct servent *s; |
| 1012 | sig sigint, sigterm; |
| 1013 | FILE *fp = 0; |
| 1014 | int i; |
| 1015 | unsigned f = 0; |
| 1016 | #define f_bogus 1u |
| 1017 | #define f_daemon 2u |
| 1018 | const struct addrops *ao; |
| 1019 | int any = 0; |
| 1020 | |
| 1021 | ego(argv[0]); |
| 1022 | |
| 1023 | /* Parse command-line options. */ |
| 1024 | for (;;) { |
| 1025 | const struct option opts[] = { |
| 1026 | { "help", 0, 0, 'h' }, |
| 1027 | { "version", 0, 0, 'v' }, |
| 1028 | { "usage", 0, 0, 'u' }, |
| 1029 | { "daemon", 0, 0, 'D' }, |
| 1030 | { "group", OPTF_ARGREQ, 0, 'G' }, |
| 1031 | { "pidfile", OPTF_ARGREQ, 0, 'P' }, |
| 1032 | { "user", OPTF_ARGREQ, 0, 'U' }, |
| 1033 | { "config", OPTF_ARGREQ, 0, 'c' }, |
| 1034 | { "syslog", 0, 0, 'l' }, |
| 1035 | { "port", OPTF_ARGREQ, 0, 'p' }, |
| 1036 | { 0, 0, 0, 0 } |
| 1037 | }; |
| 1038 | |
| 1039 | if ((i = mdwopt(argc, argv, "hvuDG:P:U:c:lp:", opts, 0, 0, 0)) < 0) |
| 1040 | break; |
| 1041 | switch (i) { |
| 1042 | case 'h': help(stdout); exit(0); |
| 1043 | case 'v': version(stdout); exit(0); |
| 1044 | case 'u': usage(stdout); exit(0); |
| 1045 | case 'D': f |= f_daemon; break; |
| 1046 | case 'P': pidfile = optarg; break; |
| 1047 | case 'c': policyfile = optarg; break; |
| 1048 | case 'l': flags |= F_SYSLOG; break; |
| 1049 | case 'G': |
| 1050 | if (numericp(optarg)) |
| 1051 | g = atoi(optarg); |
| 1052 | else if ((gr = getgrnam(optarg)) == 0) |
| 1053 | die(1, "unknown group `%s'", optarg); |
| 1054 | else |
| 1055 | g = gr->gr_gid; |
| 1056 | break; |
| 1057 | case 'U': |
| 1058 | if (numericp(optarg)) |
| 1059 | u = atoi(optarg); |
| 1060 | else if ((pw = getpwnam(optarg)) == 0) |
| 1061 | die(1, "unknown user `%s'", optarg); |
| 1062 | else |
| 1063 | u = pw->pw_uid; |
| 1064 | break; |
| 1065 | case 'p': |
| 1066 | if (numericp(optarg)) |
| 1067 | port = atoi(optarg); |
| 1068 | else if ((s = getservbyname(optarg, "tcp")) == 0) |
| 1069 | die(1, "unknown service name `%s'", optarg); |
| 1070 | else |
| 1071 | port = ntohs(s->s_port); |
| 1072 | break; |
| 1073 | default: f |= f_bogus; break; |
| 1074 | } |
| 1075 | } |
| 1076 | if (optind < argc) f |= f_bogus; |
| 1077 | if (f & f_bogus) { usage(stderr); exit(1); } |
| 1078 | |
| 1079 | /* If a user has been requested, but no group, then find the user's primary |
| 1080 | * group. If the user was given by name, then we already have a password |
| 1081 | * entry and should use that, in case two differently-named users have the |
| 1082 | * same uid but distinct gids. |
| 1083 | */ |
| 1084 | if (u != -1 && g == -1) { |
| 1085 | if (!pw && (pw = getpwuid(u)) == 0) { |
| 1086 | die(1, "failed to find password entry for user %d: " |
| 1087 | "request group explicitly", u); |
| 1088 | } |
| 1089 | g = pw->pw_gid; |
| 1090 | } |
| 1091 | |
| 1092 | /* Initialize system-specific machinery. */ |
| 1093 | init_sys(); |
| 1094 | |
| 1095 | /* Load the global policy rules. */ |
| 1096 | fwatch_init(&polfw, policyfile); |
| 1097 | if (load_policy_file(policyfile, &policy)) |
| 1098 | exit(1); |
| 1099 | |
| 1100 | /* Set up the I/O event system. */ |
| 1101 | sel_init(&sel); |
| 1102 | |
| 1103 | /* Watch for some interesting signals. */ |
| 1104 | sig_init(&sel); |
| 1105 | sig_add(&sigint, SIGINT, quit, "SIGINT"); |
| 1106 | sig_add(&sigterm, SIGTERM, quit, "SIGTERM"); |
| 1107 | |
| 1108 | /* Listen for incoming connections. */ |
| 1109 | for (ao = addroptab; ao->name; ao++) |
| 1110 | if (!make_listening_socket(ao, port)) any = 1; |
| 1111 | if (!any) die(1, "no IP protocols supported"); |
| 1112 | |
| 1113 | /* Open the pidfile now, in case it's somewhere we can't write. */ |
| 1114 | if (pidfile && (fp = fopen(pidfile, "w")) == 0) { |
| 1115 | die(1, "failed to open pidfile `%s' for writing: %s", |
| 1116 | pidfile, strerror(errno)); |
| 1117 | } |
| 1118 | |
| 1119 | /* If we're meant to use syslog, then open the log. */ |
| 1120 | if (flags & F_SYSLOG) |
| 1121 | openlog(QUIS, 0, LOG_DAEMON); |
| 1122 | |
| 1123 | /* Drop privileges. */ |
| 1124 | if ((g != -1 && (setegid(g) || setgid(g) || |
| 1125 | (getuid() == 0 && setgroups(1, &g)))) || |
| 1126 | (u != -1 && setuid(u))) |
| 1127 | die(1, "failed to drop privileges: %s", strerror(errno)); |
| 1128 | |
| 1129 | /* Become a background process, if requested. */ |
| 1130 | if ((f & f_daemon) && daemonize()) |
| 1131 | die(1, "failed to become daemon: %s", strerror(errno)); |
| 1132 | |
| 1133 | /* Write the process id to the pidfile. */ |
| 1134 | if (fp) { |
| 1135 | fprintf(fp, "%d\n", getpid()); |
| 1136 | fclose(fp); |
| 1137 | } |
| 1138 | |
| 1139 | /* And now we're going. */ |
| 1140 | flags |= F_RUNNING; |
| 1141 | |
| 1142 | /* Read events and process them. */ |
| 1143 | for (;;) { |
| 1144 | if (sel_select(&sel) && errno != EINTR) |
| 1145 | die(1, "select failed: %s", strerror(errno)); |
| 1146 | reap_dead_proxies(); |
| 1147 | reap_dead_clients(); |
| 1148 | } |
| 1149 | |
| 1150 | /* This just keeps the compiler happy. */ |
| 1151 | return (0); |
| 1152 | } |
| 1153 | |
| 1154 | /*----- That's all, folks -------------------------------------------------*/ |