Commit | Line | Data |
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9da480be MW |
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 | ||
c3794524 MW |
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 | */ | |
9da480be MW |
36 | #define WRBUFSZ 1024 |
37 | struct writebuf { | |
c3794524 MW |
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 */ | |
9da480be MW |
44 | }; |
45 | ||
c3794524 MW |
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 */ | |
9da480be MW |
52 | }; |
53 | ||
c3794524 | 54 | /* The main structure for a client. */ |
9da480be | 55 | struct client { |
c3794524 MW |
56 | int fd; /* The connection to the client */ |
57 | selbuf b; /* Accumulate lines of input */ | |
58 | struct query q; /* The clients query and our reply */ | |
4f8fdcc1 | 59 | struct sel_timer t; /* Timeout for idle or doomed conn */ |
c3794524 MW |
60 | struct listen *l; /* Back to the listener (and ops) */ |
61 | struct writebuf wb; /* Write buffer for our reply */ | |
62 | struct proxy *px; /* Proxy if conn goes via NAT */ | |
63 | }; | |
64 | ||
65 | /* A proxy connection. */ | |
66 | struct proxy { | |
67 | int fd; /* Connection; -1 if in progress */ | |
68 | struct client *c; /* Back to the client */ | |
69 | conn cn; /* Nonblocking connection */ | |
70 | selbuf b; /* Accumulate the response line */ | |
71 | struct writebuf wb; /* Write buffer for query */ | |
72 | char nat[ADDRLEN]; /* Server address, as text */ | |
9da480be MW |
73 | }; |
74 | ||
75 | /*----- Static variables --------------------------------------------------*/ | |
76 | ||
c3794524 | 77 | static sel_state sel; /* I/O multiplexer state */ |
9da480be | 78 | |
74716d82 MW |
79 | static const char *pidfile = 0; /* Where to write daemon's pid */ |
80 | ||
81 | static const char *policyfile = POLICYFILE; /* Filename for global policy */ | |
c3794524 MW |
82 | static const struct policy default_policy = POLICY_INIT(A_NAME); |
83 | static policy_v policy = DA_INIT; /* Vector of global policy rules */ | |
84 | static fwatch polfw; /* Watch policy file for changes */ | |
9da480be | 85 | |
c3794524 MW |
86 | static unsigned char tokenbuf[4096]; /* Random-ish data for tokens */ |
87 | static size_t tokenptr = sizeof(tokenbuf); /* Current read position */ | |
88 | static int randfd; /* File descriptor for random data */ | |
9da480be | 89 | |
74716d82 MW |
90 | static unsigned flags = 0; /* Various interesting flags */ |
91 | #define F_SYSLOG 1u /* Use syslog for logging */ | |
92 | #define F_RUNNING 2u /* Running properly now */ | |
93 | ||
c3794524 | 94 | /*----- Ident protocol parsing --------------------------------------------*/ |
9da480be | 95 | |
c3794524 MW |
96 | /* Advance *PP over whitespace characters. */ |
97 | static void skipws(const char **pp) | |
98 | { while (isspace((unsigned char )**pp)) (*pp)++; } | |
99 | ||
100 | /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP | |
101 | * over it. | |
102 | */ | |
103 | static int idtoken(const char **pp, char *q, size_t n) | |
9da480be | 104 | { |
c3794524 | 105 | const char *p = *pp; |
9da480be | 106 | |
c3794524 MW |
107 | skipws(&p); |
108 | n--; | |
109 | for (;;) { | |
110 | if (*p == ':' || *p <= 32 || *p >= 127) break; | |
111 | if (!n) return (-1); | |
112 | *q++ = *p++; | |
113 | n--; | |
9da480be | 114 | } |
c3794524 MW |
115 | *q++ = 0; |
116 | *pp = p; | |
117 | return (0); | |
118 | } | |
119 | ||
120 | /* Read an unsigned decimal number from *PP, and store it in *II. Check that | |
121 | * it's between MIN and MAX, and advance *PP over it. Return zero for | |
122 | * success, or nonzero if something goes wrong. | |
123 | */ | |
124 | static int unum(const char **pp, unsigned *ii, unsigned min, unsigned max) | |
125 | { | |
126 | char *q; | |
127 | unsigned long i; | |
128 | int e; | |
129 | ||
130 | skipws(pp); | |
131 | if (!isdigit((unsigned char)**pp)) return (-1); | |
132 | e = errno; errno = 0; | |
133 | i = strtoul(*pp, &q, 10); | |
134 | if (errno) return (-1); | |
135 | *pp = q; | |
136 | errno = e; | |
137 | if (i < min || i > max) return (-1); | |
138 | *ii = i; | |
139 | return (0); | |
9da480be MW |
140 | } |
141 | ||
c3794524 MW |
142 | /*----- Asynchronous writing ----------------------------------------------*/ |
143 | ||
144 | /* Callback for actually writing stuff from a `writebuf'. */ | |
9da480be MW |
145 | static void write_out(int fd, unsigned mode, void *p) |
146 | { | |
147 | ssize_t n; | |
148 | struct writebuf *wb = p; | |
149 | ||
c3794524 | 150 | /* Try to write something. */ |
9da480be MW |
151 | if ((n = write(fd, wb->buf + wb->o, wb->n)) < 0) { |
152 | if (errno == EAGAIN || errno == EWOULDBLOCK) return; | |
153 | wb->n = 0; | |
154 | sel_rmfile(&wb->wr); | |
155 | wb->func(errno, wb->p); | |
156 | } | |
157 | wb->o += n; | |
158 | wb->n -= n; | |
c3794524 MW |
159 | |
160 | /* If there's nothing left then restore the buffer to its empty state. */ | |
9da480be MW |
161 | if (!wb->n) { |
162 | wb->o = 0; | |
163 | sel_rmfile(&wb->wr); | |
164 | wb->func(0, wb->p); | |
165 | } | |
166 | } | |
167 | ||
c3794524 | 168 | /* Queue N bytes starting at P to be written. */ |
9da480be MW |
169 | static int queue_write(struct writebuf *wb, const void *p, size_t n) |
170 | { | |
c3794524 | 171 | /* Maybe there's nothing to actually do. */ |
9da480be | 172 | if (!n) return (0); |
c3794524 MW |
173 | |
174 | /* Make sure it'll fit. */ | |
9da480be | 175 | if (wb->n - wb->o + n > WRBUFSZ) return (-1); |
c3794524 MW |
176 | |
177 | /* If there's anything there already, then make sure it's at the start of | |
178 | * the available space. | |
179 | */ | |
9da480be MW |
180 | if (wb->o) { |
181 | memmove(wb->buf, wb->buf + wb->o, wb->n); | |
182 | wb->o = 0; | |
183 | } | |
c3794524 MW |
184 | |
185 | /* If there's nothing currently there, then we're not requesting write | |
186 | * notifications, so set that up, and force an initial wake-up. | |
187 | */ | |
9da480be MW |
188 | if (!wb->n) { |
189 | sel_addfile(&wb->wr); | |
190 | sel_force(&wb->wr); | |
191 | } | |
c3794524 MW |
192 | |
193 | /* Copy the new material over. */ | |
194 | memcpy(wb->buf + wb->n, p, n); | |
9da480be | 195 | wb->n += n; |
c3794524 MW |
196 | |
197 | /* Done. */ | |
9da480be MW |
198 | return (0); |
199 | } | |
200 | ||
c3794524 | 201 | /* Release resources allocated to WB. */ |
9da480be MW |
202 | static void free_writebuf(struct writebuf *wb) |
203 | { if (wb->n) sel_rmfile(&wb->wr); } | |
204 | ||
c3794524 MW |
205 | /* Initialize a writebuf in *WB, writing to file descriptor FD. On |
206 | * completion, call FUNC, passing it P and an error indicator: either 0 for | |
207 | * success or an `errno' value on failure. | |
208 | */ | |
9da480be MW |
209 | static void init_writebuf(struct writebuf *wb, |
210 | int fd, void (*func)(int, void *), void *p) | |
211 | { | |
212 | sel_initfile(&sel, &wb->wr, fd, SEL_WRITE, write_out, wb); | |
213 | wb->func = func; | |
214 | wb->p = p; | |
215 | wb->n = wb->o = 0; | |
216 | } | |
217 | ||
c3794524 | 218 | /*----- General utilities -------------------------------------------------*/ |
9da480be | 219 | |
c3794524 MW |
220 | /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO. |
221 | * Prefix it with a description of the query Q, if non-null. | |
222 | */ | |
223 | void logmsg(const struct query *q, int prio, const char *msg, ...) | |
9da480be | 224 | { |
c3794524 MW |
225 | va_list ap; |
226 | dstr d = DSTR_INIT; | |
74716d82 MW |
227 | time_t t; |
228 | struct tm *tm; | |
229 | char buf[64]; | |
c3794524 MW |
230 | |
231 | va_start(ap, msg); | |
232 | if (q) { | |
233 | dputsock(&d, q->ao, &q->s[L]); | |
234 | dstr_puts(&d, " <-> "); | |
235 | dputsock(&d, q->ao, &q->s[R]); | |
236 | dstr_puts(&d, ": "); | |
237 | } | |
238 | dstr_vputf(&d, msg, &ap); | |
239 | va_end(ap); | |
74716d82 MW |
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 | ||
c3794524 | 252 | dstr_destroy(&d); |
9da480be MW |
253 | } |
254 | ||
c3794524 MW |
255 | /* Fix up a socket FD so that it won't bite us. Returns zero on success, or |
256 | * nonzero on error. | |
257 | */ | |
95df134c MW |
258 | static int fix_up_socket(int fd, const char *what) |
259 | { | |
260 | int yes = 1; | |
261 | ||
262 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { | |
263 | logmsg(0, LOG_ERR, "failed to set %s connection nonblocking: %s", | |
264 | what, strerror(errno)); | |
265 | return (-1); | |
266 | } | |
267 | ||
268 | if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &yes, sizeof(yes))) { | |
269 | logmsg(0, LOG_ERR, | |
270 | "failed to disable `out-of-band' data on %s connection: %s", | |
271 | what, strerror(errno)); | |
272 | return (-1); | |
273 | } | |
274 | ||
275 | return (0); | |
276 | } | |
277 | ||
c3794524 MW |
278 | /*----- Client output functions -------------------------------------------*/ |
279 | ||
280 | static void disconnect_client(struct client *c); | |
281 | ||
282 | /* Notification that output has been written. If successful, re-enable the | |
283 | * input buffer and prepare for another query. | |
284 | */ | |
9da480be MW |
285 | static void done_client_write(int err, void *p) |
286 | { | |
287 | struct client *c = p; | |
288 | ||
289 | if (!err) | |
290 | selbuf_enable(&c->b); | |
291 | else { | |
292 | logmsg(&c->q, LOG_ERR, "failed to send reply: %s", strerror(err)); | |
293 | disconnect_client(c); | |
294 | } | |
295 | } | |
296 | ||
c3794524 MW |
297 | /* Format the message FMT and queue it to be sent to the client. Client |
298 | * input will be disabled until the write completes. | |
299 | */ | |
9da480be MW |
300 | static void write_to_client(struct client *c, const char *fmt, ...) |
301 | { | |
302 | va_list ap; | |
303 | char buf[WRBUFSZ]; | |
304 | ssize_t n; | |
305 | ||
306 | va_start(ap, fmt); | |
307 | n = vsnprintf(buf, sizeof(buf), fmt, ap); | |
308 | if (n < 0) { | |
309 | logmsg(&c->q, LOG_ERR, "failed to format output: %s", strerror(errno)); | |
310 | disconnect_client(c); | |
311 | return; | |
312 | } else if (n > sizeof(buf)) { | |
313 | logmsg(&c->q, LOG_ERR, "output too long for client send buffer"); | |
314 | disconnect_client(c); | |
315 | return; | |
316 | } | |
317 | ||
318 | selbuf_disable(&c->b); | |
319 | if (queue_write(&c->wb, buf, n)) { | |
320 | logmsg(&c->q, LOG_ERR, "write buffer overflow"); | |
321 | disconnect_client(c); | |
322 | } | |
323 | } | |
324 | ||
c3794524 MW |
325 | /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1]. |
326 | * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will | |
327 | * be the error token and TOK1 will be null; in the latter case, TOK0 will be | |
328 | * the operating system and TOK1 the user name. | |
329 | */ | |
c809f908 MW |
330 | static void reply(struct client *c, const char *ty, |
331 | const char *tok0, const char *tok1) | |
9da480be | 332 | { |
c809f908 MW |
333 | write_to_client(c, "%u,%u:%s:%s%s%s\r\n", |
334 | c->q.s[L].port, c->q.s[R].port, ty, | |
335 | tok0, tok1 ? ":" : "", tok1 ? tok1 : ""); | |
9da480be MW |
336 | } |
337 | ||
c3794524 | 338 | /* Mapping from error codes to their protocol tokens. */ |
bf4d9761 MW |
339 | const char *const errtok[] = { |
340 | #define DEFTOK(err, tok) tok, | |
341 | ERROR(DEFTOK) | |
342 | #undef DEFTOK | |
343 | }; | |
344 | ||
c3794524 | 345 | /* Report an error with code ERR to the client. */ |
9da480be MW |
346 | static void reply_error(struct client *c, unsigned err) |
347 | { | |
348 | assert(err < E_LIMIT); | |
c809f908 | 349 | reply(c, "ERROR", errtok[err], 0); |
9da480be MW |
350 | } |
351 | ||
c3794524 | 352 | /*----- NAT proxy functions -----------------------------------------------*/ |
9da480be | 353 | |
c3794524 MW |
354 | /* Cancel the proxy operation PX, closing the connection and releasing |
355 | * resources. This is used for both normal and unexpected closures. | |
356 | */ | |
357 | static void cancel_proxy(struct proxy *px) | |
9da480be | 358 | { |
c3794524 MW |
359 | if (px->fd == -1) |
360 | conn_kill(&px->cn); | |
361 | else { | |
362 | close(px->fd); | |
363 | selbuf_destroy(&px->b); | |
364 | free_writebuf(&px->wb); | |
9da480be | 365 | } |
c3794524 MW |
366 | selbuf_enable(&px->c->b); |
367 | px->c->px = 0; | |
368 | xfree(px); | |
9da480be MW |
369 | } |
370 | ||
c3794524 MW |
371 | /* Notification that a line (presumably a reply) has been received from the |
372 | * server. We should check it, log it, and propagate the answer back. | |
373 | * Whatever happens, this proxy operation is now complete. | |
374 | */ | |
9da480be MW |
375 | static void proxy_line(char *line, size_t sz, void *p) |
376 | { | |
377 | struct proxy *px = p; | |
378 | char buf[1024]; | |
379 | const char *q = line; | |
380 | unsigned lp, rp; | |
381 | ||
c3794524 | 382 | /* Trim trailing space. */ |
9da480be | 383 | while (sz && isspace((unsigned char)line[sz - 1])) sz--; |
9da480be | 384 | |
c3794524 | 385 | /* Parse the port numbers. These should match the request. */ |
9da480be MW |
386 | if (unum(&q, &lp, 1, 65535)) goto syntax; |
387 | skipws(&q); if (*q != ',') goto syntax; q++; | |
388 | if (unum(&q, &rp, 1, 65535)) goto syntax; | |
389 | skipws(&q); if (*q != ':') goto syntax; q++; | |
390 | if (lp != px->c->q.u.nat.port || rp != px->c->q.s[R].port) goto syntax; | |
c3794524 MW |
391 | |
392 | /* Find out what kind of reply this is. */ | |
9da480be MW |
393 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
394 | skipws(&q); if (*q != ':') goto syntax; q++; | |
c3794524 | 395 | |
9da480be | 396 | if (strcmp(buf, "ERROR") == 0) { |
c3794524 MW |
397 | |
398 | /* Report the error without interpreting it. It might be meaningful to | |
399 | * the client. | |
400 | */ | |
9da480be MW |
401 | skipws(&q); |
402 | logmsg(&px->c->q, LOG_ERR, "proxy error from %s: %s", px->nat, q); | |
c809f908 | 403 | reply(px->c, "ERROR", q, 0); |
c3794524 | 404 | |
9da480be | 405 | } else if (strcmp(buf, "USERID") == 0) { |
c3794524 MW |
406 | |
407 | /* Parse out the operating system and user name, and pass them on. */ | |
9da480be MW |
408 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
409 | skipws(&q); if (*q != ':') goto syntax; q++; | |
410 | skipws(&q); | |
411 | logmsg(&px->c->q, LOG_ERR, "user `%s'; proxy = %s, os = %s", | |
412 | q, px->nat, buf); | |
c809f908 | 413 | reply(px->c, "USERID", buf, q); |
c3794524 | 414 | |
9da480be MW |
415 | } else |
416 | goto syntax; | |
417 | goto done; | |
418 | ||
419 | syntax: | |
c3794524 | 420 | /* We didn't understand the message from the client. */ |
9da480be MW |
421 | logmsg(&px->c->q, LOG_ERR, "failed to parse response from %s", px->nat); |
422 | reply_error(px->c, E_UNKNOWN); | |
423 | done: | |
c3794524 | 424 | /* All finished, no matter what. */ |
9da480be MW |
425 | cancel_proxy(px); |
426 | } | |
427 | ||
c3794524 MW |
428 | /* Notification that we have written the query to the server. Await a |
429 | * response if successful. | |
430 | */ | |
9da480be MW |
431 | static void done_proxy_write(int err, void *p) |
432 | { | |
433 | struct proxy *px = p; | |
434 | ||
435 | if (err) { | |
436 | logmsg(&px->c->q, LOG_ERR, "failed to proxy query to %s: %s", | |
437 | px->nat, strerror(errno)); | |
438 | reply_error(px->c, E_UNKNOWN); | |
439 | cancel_proxy(px); | |
440 | return; | |
441 | } | |
442 | selbuf_enable(&px->b); | |
443 | } | |
444 | ||
c3794524 MW |
445 | /* Notification that the connection to the server is either established or |
446 | * failed. In the former case, queue the right query. | |
447 | */ | |
9da480be MW |
448 | static void proxy_connected(int fd, void *p) |
449 | { | |
450 | struct proxy *px = p; | |
451 | char buf[16]; | |
452 | int n; | |
453 | ||
c3794524 | 454 | /* If the connection failed then report the problem and give up. */ |
9da480be MW |
455 | if (fd < 0) { |
456 | logmsg(&px->c->q, LOG_ERR, | |
457 | "failed to make %s proxy connection to %s: %s", | |
bf4d9761 | 458 | px->c->l->ao->name, px->nat, strerror(errno)); |
9da480be MW |
459 | reply_error(px->c, E_UNKNOWN); |
460 | cancel_proxy(px); | |
461 | return; | |
462 | } | |
463 | ||
c3794524 | 464 | /* We're now ready to go, so set things up. */ |
9da480be MW |
465 | px->fd = fd; |
466 | selbuf_init(&px->b, &sel, fd, proxy_line, px); | |
467 | selbuf_setsize(&px->b, 1024); | |
468 | selbuf_disable(&px->b); | |
469 | init_writebuf(&px->wb, fd, done_proxy_write, px); | |
470 | ||
c3794524 MW |
471 | /* Write the query. This buffer is large enough because we've already |
472 | * range-checked the remote the port number and the local one came from the | |
473 | * kernel, which we trust not to do anything stupid. | |
474 | */ | |
9da480be MW |
475 | n = sprintf(buf, "%u,%u\r\n", px->c->q.u.nat.port, px->c->q.s[R].port); |
476 | queue_write(&px->wb, buf, n); | |
477 | } | |
478 | ||
c3794524 MW |
479 | /* Proxy the query through to a client machine for which we're providing NAT |
480 | * disservice. | |
481 | */ | |
9da480be MW |
482 | static void proxy_query(struct client *c) |
483 | { | |
484 | struct socket s; | |
485 | struct sockaddr_storage ss; | |
486 | size_t ssz; | |
487 | struct proxy *px; | |
9da480be MW |
488 | int fd; |
489 | ||
c3794524 | 490 | /* Allocate the context structure for the NAT. */ |
9da480be | 491 | px = xmalloc(sizeof(*px)); |
c3794524 MW |
492 | |
493 | /* We'll use the client host's address in lots of log messages, so we may | |
494 | * as well format it once and use it over and over. | |
495 | */ | |
bf4d9761 | 496 | inet_ntop(c->q.ao->af, &c->q.u.nat.addr, px->nat, sizeof(px->nat)); |
9da480be | 497 | |
c3794524 | 498 | /* Create the socket for the connection. */ |
bf4d9761 | 499 | if ((fd = socket(c->q.ao->af, SOCK_STREAM, 0)) < 0) { |
9da480be | 500 | logmsg(&c->q, LOG_ERR, "failed to make %s socket for proxy: %s", |
bf4d9761 | 501 | c->l->ao->name, strerror(errno)); |
9da480be MW |
502 | goto err_0; |
503 | } | |
95df134c | 504 | if (fix_up_socket(fd, "proxy")) goto err_1; |
9da480be | 505 | |
c3794524 MW |
506 | /* Set up the connection to the client host. The connection interface is a |
507 | * bit broken: if the connection completes immediately, then the callback | |
508 | * function is called synchronously, and that might decide to shut | |
509 | * everything down. So we must have fully initialized our context before | |
510 | * calling `conn_init', and mustn't touch it again afterwards -- since the | |
511 | * block may have been freed. | |
512 | */ | |
9da480be MW |
513 | s = c->q.u.nat; |
514 | s.port = 113; | |
bf4d9761 | 515 | c->l->ao->socket_to_sockaddr(&s, &ss, &ssz); |
9da480be | 516 | selbuf_disable(&c->b); |
79805e61 MW |
517 | c->px = px; px->c = c; |
518 | px->fd = -1; | |
9da480be MW |
519 | if (conn_init(&px->cn, &sel, fd, (struct sockaddr *)&ss, ssz, |
520 | proxy_connected, px)) { | |
521 | logmsg(&c->q, LOG_ERR, "failed to make %s proxy connection to %s: %s", | |
bf4d9761 | 522 | c->l->ao->name, px->nat, strerror(errno)); |
9da480be MW |
523 | goto err_2; |
524 | } | |
525 | ||
c3794524 | 526 | /* All ready to go. */ |
9da480be MW |
527 | return; |
528 | ||
c3794524 | 529 | /* Tidy up after various kinds of failures. */ |
9da480be MW |
530 | err_2: |
531 | selbuf_enable(&c->b); | |
532 | err_1: | |
533 | close(px->fd); | |
534 | err_0: | |
535 | xfree(px); | |
536 | reply_error(c, E_UNKNOWN); | |
537 | } | |
538 | ||
c3794524 MW |
539 | /*----- Client connection functions ---------------------------------------*/ |
540 | ||
541 | /* Disconnect a client, freeing up any associated resources. */ | |
542 | static void disconnect_client(struct client *c) | |
543 | { | |
544 | close(c->fd); | |
545 | selbuf_destroy(&c->b); | |
4f8fdcc1 | 546 | sel_rmtimer(&c->t); |
c3794524 MW |
547 | free_writebuf(&c->wb); |
548 | if (c->px) cancel_proxy(c->px); | |
549 | xfree(c); | |
550 | } | |
9da480be | 551 | |
4f8fdcc1 MW |
552 | /* Time out a client because it's been idle for too long. */ |
553 | static void timeout_client(struct timeval *tv, void *p) | |
554 | { | |
555 | struct client *c = p; | |
556 | logmsg(&c->q, LOG_NOTICE, "timing out idle or stuck client"); | |
557 | sel_addtimer(&sel, &c->t, tv, timeout_client, 0); | |
558 | disconnect_client(c); | |
559 | } | |
560 | ||
561 | /* Reset the client idle timer, as a result of activity. Set EXISTP if | |
562 | * there is an existing timer which needs to be removed. | |
563 | */ | |
564 | static void reset_client_timer(struct client *c, int existp) | |
565 | { | |
566 | struct timeval tv; | |
567 | ||
568 | gettimeofday(&tv, 0); | |
569 | tv.tv_sec += 30; | |
570 | if (existp) sel_rmtimer(&c->t); | |
571 | sel_addtimer(&sel, &c->t, &tv, timeout_client, c); | |
572 | } | |
573 | ||
c3794524 MW |
574 | /* Write a pseudorandom token into the buffer at P, which must have space for |
575 | * at least TOKENSZ bytes. | |
576 | */ | |
577 | #define TOKENRANDSZ 8 | |
578 | #define TOKENSZ ((4*TOKENRANDSZ + 5)/3) | |
9da480be MW |
579 | static void user_token(char *p) |
580 | { | |
9da480be MW |
581 | unsigned a = 0; |
582 | unsigned b = 0; | |
583 | int i; | |
c3794524 MW |
584 | static const char tokmap[64] = |
585 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-"; | |
9da480be | 586 | |
c3794524 MW |
587 | /* If there's not enough pseudorandom stuff lying around, then read more |
588 | * from the kernel. | |
589 | */ | |
590 | if (tokenptr + TOKENRANDSZ >= sizeof(tokenbuf)) { | |
9da480be MW |
591 | if (read(randfd, tokenbuf, sizeof(tokenbuf)) < sizeof(tokenbuf)) |
592 | die(1, "unexpected short read or error from `/dev/urandom'"); | |
593 | tokenptr = 0; | |
594 | } | |
595 | ||
c3794524 MW |
596 | /* Now encode the bytes using a slightly tweaked base-64 encoding. Read |
597 | * bytes into the accumulator and write out characters while there's | |
598 | * enough material. | |
599 | */ | |
600 | for (i = 0; i < TOKENRANDSZ; i++) { | |
9da480be MW |
601 | a = (a << 8) | tokenbuf[tokenptr++]; b += 8; |
602 | while (b >= 6) { | |
603 | b -= 6; | |
604 | *p++ = tokmap[(a >> b) & 0x3f]; | |
605 | } | |
606 | } | |
c3794524 MW |
607 | |
608 | /* If there's anything left in the accumulator then flush it out. */ | |
9da480be MW |
609 | if (b) |
610 | *p++ = tokmap[(a << (6 - b)) & 0x3f]; | |
c3794524 MW |
611 | |
612 | /* Null-terminate the token. */ | |
9da480be MW |
613 | *p++ = 0; |
614 | } | |
615 | ||
c3794524 MW |
616 | /* Notification that a line has been received from the client. Parse it, |
617 | * find out about the connection it's referring to, apply the relevant | |
618 | * policy rules, and produce a response. This is where almost everything | |
619 | * interesting happens. | |
620 | */ | |
9da480be MW |
621 | static void client_line(char *line, size_t len, void *p) |
622 | { | |
623 | struct client *c = p; | |
624 | const char *q; | |
625 | struct passwd *pw = 0; | |
626 | const struct policy *pol; | |
627 | dstr d = DSTR_INIT; | |
628 | struct policy upol = POLICY_INIT(A_LIMIT); | |
629 | struct policy_file pf; | |
630 | char buf[16]; | |
631 | int i; | |
632 | ||
c3794524 | 633 | /* If the connection has closed, then tidy stuff away. */ |
9da480be MW |
634 | c->q.s[L].port = c->q.s[R].port = 0; |
635 | if (!line) { | |
636 | disconnect_client(c); | |
637 | return; | |
638 | } | |
639 | ||
4f8fdcc1 MW |
640 | /* Client activity, so update the timer. */ |
641 | reset_client_timer(c, 1); | |
642 | ||
c3794524 MW |
643 | /* See if the policy file has changed since we last looked. If so, try to |
644 | * read the new version. | |
645 | */ | |
74716d82 MW |
646 | if (fwatch_update(&polfw, policyfile)) { |
647 | logmsg(0, LOG_INFO, "reload master policy file `%s'", policyfile); | |
648 | load_policy_file(policyfile, &policy); | |
9da480be MW |
649 | } |
650 | ||
c3794524 | 651 | /* Read the local and remote port numbers into the query structure. */ |
9da480be MW |
652 | q = line; |
653 | if (unum(&q, &c->q.s[L].port, 1, 65535)) goto bad; | |
654 | skipws(&q); if (*q != ',') goto bad; q++; | |
655 | if (unum(&q, &c->q.s[R].port, 1, 65535)) goto bad; | |
656 | skipws(&q); if (*q) goto bad; | |
657 | ||
c3794524 | 658 | /* Identify the connection. Act on the result. */ |
9da480be MW |
659 | identify(&c->q); |
660 | switch (c->q.resp) { | |
c3794524 | 661 | |
9da480be | 662 | case R_UID: |
c3794524 MW |
663 | /* We found a user. Track down the user's password entry, because |
664 | * we'll want that later. Most of the processing for this case is | |
665 | * below. | |
666 | */ | |
9da480be MW |
667 | if ((pw = getpwuid(c->q.u.uid)) == 0) { |
668 | logmsg(&c->q, LOG_ERR, "no passwd entry for user %d", c->q.u.uid); | |
669 | reply_error(c, E_NOUSER); | |
670 | return; | |
671 | } | |
672 | break; | |
c3794524 | 673 | |
9da480be | 674 | case R_NAT: |
c3794524 MW |
675 | /* We've acted as a NAT for this connection. Proxy the query through |
676 | * to the actal client host. | |
677 | */ | |
9da480be MW |
678 | proxy_query(c); |
679 | return; | |
c3794524 | 680 | |
9da480be | 681 | case R_ERROR: |
c3794524 MW |
682 | /* We failed to identify the connection for some reason. We should |
683 | * already have logged an error, so there's not much to do here. | |
684 | */ | |
9da480be MW |
685 | reply_error(c, c->q.u.error); |
686 | return; | |
c3794524 | 687 | |
9da480be | 688 | default: |
c3794524 | 689 | /* Something happened that we don't understand. */ |
9da480be MW |
690 | abort(); |
691 | } | |
692 | ||
c3794524 | 693 | /* Search the table of policy rules to find a match. */ |
9da480be MW |
694 | for (i = 0; i < DA_LEN(&policy); i++) { |
695 | pol = &DA(&policy)[i]; | |
696 | if (!match_policy(pol, &c->q)) continue; | |
c3794524 MW |
697 | |
698 | /* If this is something simple, then apply the resulting policy rule. */ | |
699 | if (pol->act.act != A_USER) goto match; | |
700 | ||
701 | /* The global policy has decided to let the user have a say, so we must | |
702 | * parse the user file. | |
703 | */ | |
9da480be MW |
704 | DRESET(&d); |
705 | dstr_putf(&d, "%s/.yaid.policy", pw->pw_dir); | |
706 | if (open_policy_file(&pf, d.buf, "user policy file", &c->q)) | |
707 | continue; | |
708 | while (!read_policy_file(&pf)) { | |
c3794524 MW |
709 | |
710 | /* Give up after 100 lines. If the user's policy is that complicated, | |
711 | * something's gone very wrong. Or there's too much commentary or | |
712 | * something. | |
713 | */ | |
9da480be MW |
714 | if (pf.lno > 100) { |
715 | logmsg(&c->q, LOG_ERR, "%s:%d: user policy file too long", | |
716 | pf.name, pf.lno); | |
717 | break; | |
718 | } | |
c3794524 MW |
719 | |
720 | /* If this isn't a match, go around for the next rule. */ | |
9da480be | 721 | if (!match_policy(&pf.p, &c->q)) continue; |
c3794524 MW |
722 | |
723 | /* Check that the user is allowed to request this action. If not, see | |
724 | * if there's a more acceptable action later on. | |
725 | */ | |
9da480be MW |
726 | if (!(pol->act.u.user & (1 << pf.p.act.act))) { |
727 | logmsg(&c->q, LOG_ERR, | |
728 | "%s:%d: user action forbidden by global policy", | |
729 | pf.name, pf.lno); | |
730 | continue; | |
731 | } | |
c3794524 MW |
732 | |
733 | /* We've found a match, so grab it, close the file, and say we're | |
734 | * done. | |
735 | */ | |
9da480be MW |
736 | upol = pf.p; pol = &upol; |
737 | init_policy(&pf.p); | |
738 | close_policy_file(&pf); | |
c3794524 | 739 | DDESTROY(&d); |
9da480be MW |
740 | goto match; |
741 | } | |
742 | close_policy_file(&pf); | |
c3794524 | 743 | DDESTROY(&d); |
9da480be | 744 | } |
c3794524 MW |
745 | |
746 | /* No match: apply the built-in default policy. */ | |
9da480be MW |
747 | pol = &default_policy; |
748 | ||
749 | match: | |
9da480be | 750 | switch (pol->act.act) { |
c3794524 | 751 | |
9da480be | 752 | case A_NAME: |
c3794524 | 753 | /* Report the actual user's name. */ |
9da480be | 754 | logmsg(&c->q, LOG_INFO, "user `%s' (%d)", pw->pw_name, c->q.u.uid); |
c809f908 | 755 | reply(c, "USERID", "UNIX", pw->pw_name); |
9da480be | 756 | break; |
c3794524 | 757 | |
9da480be | 758 | case A_TOKEN: |
c3794524 | 759 | /* Report an arbitrary token which we can look up in our log file. */ |
9da480be MW |
760 | user_token(buf); |
761 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); token = %s", | |
762 | pw->pw_name, c->q.u.uid, buf); | |
c809f908 | 763 | reply(c, "USERID", "OTHER", buf); |
9da480be | 764 | break; |
c3794524 | 765 | |
9da480be | 766 | case A_DENY: |
c3794524 | 767 | /* Deny that there's anyone there at all. */ |
9da480be MW |
768 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); denying", |
769 | pw->pw_name, c->q.u.uid); | |
770 | break; | |
c3794524 | 771 | |
9da480be | 772 | case A_HIDE: |
c3794524 | 773 | /* Report the user as being hidden. */ |
9da480be MW |
774 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); hiding", |
775 | pw->pw_name, c->q.u.uid); | |
776 | reply_error(c, E_HIDDEN); | |
777 | break; | |
c3794524 | 778 | |
9da480be | 779 | case A_LIE: |
c3794524 | 780 | /* Tell an egregious lie about who the user is. */ |
9da480be MW |
781 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); lie = `%s'", |
782 | pw->pw_name, c->q.u.uid, pol->act.u.lie); | |
c809f908 | 783 | reply(c, "USERID", "UNIX", pol->act.u.lie); |
9da480be | 784 | break; |
c3794524 | 785 | |
9da480be | 786 | default: |
c3794524 | 787 | /* Something has gone very wrong. */ |
9da480be MW |
788 | abort(); |
789 | } | |
790 | ||
c3794524 | 791 | /* All done. */ |
9da480be MW |
792 | free_policy(&upol); |
793 | return; | |
794 | ||
795 | bad: | |
796 | logmsg(&c->q, LOG_ERR, "failed to parse query from client"); | |
797 | disconnect_client(c); | |
798 | } | |
799 | ||
c3794524 | 800 | /* Notification that a new client has connected. Prepare to read a query. */ |
9da480be MW |
801 | static void accept_client(int fd, unsigned mode, void *p) |
802 | { | |
803 | struct listen *l = p; | |
804 | struct client *c; | |
805 | struct sockaddr_storage ssr, ssl; | |
806 | size_t ssz = sizeof(ssr); | |
807 | int sk; | |
808 | ||
c3794524 | 809 | /* Accept the new connection. */ |
9da480be MW |
810 | if ((sk = accept(fd, (struct sockaddr *)&ssr, &ssz)) < 0) { |
811 | if (errno != EAGAIN && errno == EWOULDBLOCK) { | |
812 | logmsg(0, LOG_ERR, "failed to accept incoming %s connection: %s", | |
bf4d9761 | 813 | l->ao->name, strerror(errno)); |
9da480be MW |
814 | } |
815 | return; | |
816 | } | |
95df134c | 817 | if (fix_up_socket(sk, "incoming client")) { close(sk); return; } |
9da480be | 818 | |
c3794524 | 819 | /* Build a client block and fill it in. */ |
9da480be MW |
820 | c = xmalloc(sizeof(*c)); |
821 | c->l = l; | |
bf4d9761 | 822 | c->q.ao = l->ao; |
c3794524 MW |
823 | |
824 | /* Collect the local and remote addresses. */ | |
bf4d9761 | 825 | l->ao->sockaddr_to_addr(&ssr, &c->q.s[R].addr); |
9da480be MW |
826 | ssz = sizeof(ssl); |
827 | if (getsockname(sk, (struct sockaddr *)&ssl, &ssz)) { | |
828 | logmsg(0, LOG_ERR, | |
829 | "failed to read local address for incoming %s connection: %s", | |
bf4d9761 | 830 | l->ao->name, strerror(errno)); |
9da480be MW |
831 | close(sk); |
832 | xfree(c); | |
833 | return; | |
834 | } | |
bf4d9761 | 835 | l->ao->sockaddr_to_addr(&ssl, &c->q.s[L].addr); |
9da480be MW |
836 | c->q.s[L].port = c->q.s[R].port = 0; |
837 | ||
c3794524 | 838 | /* Set stuff up for reading the query and sending responses. */ |
9da480be MW |
839 | selbuf_init(&c->b, &sel, sk, client_line, c); |
840 | selbuf_setsize(&c->b, 1024); | |
4f8fdcc1 | 841 | reset_client_timer(c, 0); |
9da480be MW |
842 | c->fd = sk; |
843 | c->px = 0; | |
844 | init_writebuf(&c->wb, sk, done_client_write, c); | |
845 | } | |
846 | ||
c3794524 MW |
847 | /*----- Main code ---------------------------------------------------------*/ |
848 | ||
849 | /* Set up a listening socket for the address family described by AO, | |
850 | * listening on PORT. | |
851 | */ | |
bf4d9761 | 852 | static int make_listening_socket(const struct addrops *ao, int port) |
9da480be MW |
853 | { |
854 | int fd; | |
bf4d9761 MW |
855 | int yes = 1; |
856 | struct socket s; | |
9da480be MW |
857 | struct sockaddr_storage ss; |
858 | struct listen *l; | |
859 | size_t ssz; | |
860 | ||
c3794524 | 861 | /* Make the socket. */ |
bf4d9761 | 862 | if ((fd = socket(ao->af, SOCK_STREAM, 0)) < 0) { |
a20696ca | 863 | if (errno == EAFNOSUPPORT) return (-1); |
9da480be | 864 | die(1, "failed to create %s listening socket: %s", |
bf4d9761 | 865 | ao->name, strerror(errno)); |
9da480be | 866 | } |
c3794524 MW |
867 | |
868 | /* Build the appropriate local address. */ | |
bf4d9761 MW |
869 | s.addr = *ao->any; |
870 | s.port = port; | |
871 | ao->socket_to_sockaddr(&s, &ss, &ssz); | |
c3794524 MW |
872 | |
873 | /* Perform any initialization specific to the address type. */ | |
bf4d9761 MW |
874 | if (ao->init_listen_socket(fd)) { |
875 | die(1, "failed to initialize %s listening socket: %s", | |
876 | ao->name, strerror(errno)); | |
877 | } | |
c3794524 MW |
878 | |
879 | /* Bind to the address. */ | |
880 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)); | |
bf4d9761 MW |
881 | if (bind(fd, (struct sockaddr *)&ss, ssz)) { |
882 | die(1, "failed to bind %s listening socket: %s", | |
883 | ao->name, strerror(errno)); | |
9da480be | 884 | } |
c3794524 MW |
885 | |
886 | /* Avoid unpleasant race conditions. */ | |
bf4d9761 | 887 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { |
9da480be | 888 | die(1, "failed to set %s listening socket nonblocking: %s", |
bf4d9761 | 889 | ao->name, strerror(errno)); |
9da480be | 890 | } |
c3794524 MW |
891 | |
892 | /* Prepare to listen. */ | |
9da480be | 893 | if (listen(fd, 5)) |
bf4d9761 | 894 | die(1, "failed to listen for %s: %s", ao->name, strerror(errno)); |
9da480be | 895 | |
c3794524 | 896 | /* Make a record of all of this. */ |
9da480be | 897 | l = xmalloc(sizeof(*l)); |
bf4d9761 | 898 | l->ao = ao; |
9da480be MW |
899 | sel_initfile(&sel, &l->f, fd, SEL_READ, accept_client, l); |
900 | sel_addfile(&l->f); | |
901 | ||
c3794524 | 902 | /* Done. */ |
a20696ca | 903 | return (0); |
9da480be MW |
904 | } |
905 | ||
74716d82 MW |
906 | /* Quit because of a fatal signal. */ |
907 | static void quit(int sig, void *p) | |
908 | { | |
909 | const char *signame = p; | |
910 | ||
911 | logmsg(0, LOG_NOTICE, "shutting down on %s", signame); | |
912 | if (pidfile) unlink(pidfile); | |
913 | exit(0); | |
914 | } | |
915 | ||
916 | /* Answer whether the string pointed to by P consists entirely of digits. */ | |
917 | static int numericp(const char *p) | |
918 | { | |
919 | while (*p) | |
920 | if (!isdigit((unsigned char)*p++)) return (0); | |
921 | return (1); | |
922 | } | |
923 | ||
924 | static void usage(FILE *fp) | |
925 | { | |
926 | pquis(fp, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] " | |
927 | "[-c FILE] [-p PORT]\n"); | |
928 | } | |
929 | ||
930 | static void version(FILE *fp) | |
931 | { pquis(fp, "$, version " VERSION "\n"); } | |
932 | ||
933 | static void help(FILE *fp) | |
934 | { | |
935 | version(fp); fputc('\n', fp); | |
936 | usage(fp); | |
937 | fputs("\n\ | |
938 | Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\ | |
939 | It's just a shame none of the others do the right things.\n\ | |
940 | \n\ | |
941 | Options:\n\ | |
942 | \n\ | |
943 | -h, --help Show this help message.\n\ | |
944 | -v, --version Show the version number.\n\ | |
945 | -u, --usage Show a very short usage summary.\n\ | |
946 | \n\ | |
947 | -D, --daemon Become a daemon, running in the background.\n\ | |
948 | -G, --group=GROUP Set group after initialization.\n\ | |
949 | -P, --pidfile=FILE Write process id to FILE.\n\ | |
950 | -U, --user=USER Set user after initialization.\n\ | |
951 | -c, --config=FILE Read global policy from FILE.\n\ | |
952 | -l, --syslog Write log messages using syslog(3).\n\ | |
953 | -p, --port=PORT Listen for connections on this port.\n", | |
954 | fp); | |
955 | } | |
956 | ||
9da480be MW |
957 | int main(int argc, char *argv[]) |
958 | { | |
959 | int port = 113; | |
74716d82 MW |
960 | uid_t u = -1; |
961 | gid_t g = -1; | |
962 | struct passwd *pw = 0; | |
963 | struct group *gr; | |
964 | struct servent *s; | |
965 | sig sigint, sigterm; | |
966 | FILE *fp = 0; | |
967 | int i; | |
968 | unsigned f = 0; | |
969 | #define f_bogus 1u | |
970 | #define f_daemon 2u | |
bf4d9761 MW |
971 | const struct addrops *ao; |
972 | int any = 0; | |
9da480be MW |
973 | |
974 | ego(argv[0]); | |
975 | ||
74716d82 MW |
976 | /* Parse command-line options. */ |
977 | for (;;) { | |
978 | const struct option opts[] = { | |
979 | { "help", 0, 0, 'h' }, | |
980 | { "version", 0, 0, 'v' }, | |
981 | { "usage", 0, 0, 'u' }, | |
982 | { "daemon", 0, 0, 'D' }, | |
983 | { "group", OPTF_ARGREQ, 0, 'G' }, | |
984 | { "pidfile", OPTF_ARGREQ, 0, 'P' }, | |
985 | { "user", OPTF_ARGREQ, 0, 'U' }, | |
986 | { "config", OPTF_ARGREQ, 0, 'c' }, | |
987 | { "syslog", 0, 0, 'l' }, | |
988 | { "port", OPTF_ARGREQ, 0, 'p' }, | |
989 | { 0, 0, 0, 0 } | |
990 | }; | |
991 | ||
992 | if ((i = mdwopt(argc, argv, "hvuDG:P:U:c:lp:", opts, 0, 0, 0)) < 0) | |
993 | break; | |
994 | switch (i) { | |
995 | case 'h': help(stdout); exit(0); | |
996 | case 'v': version(stdout); exit(0); | |
997 | case 'u': usage(stdout); exit(0); | |
998 | case 'D': f |= f_daemon; break; | |
999 | case 'P': pidfile = optarg; break; | |
1000 | case 'c': policyfile = optarg; break; | |
1001 | case 'l': flags |= F_SYSLOG; break; | |
1002 | case 'G': | |
1003 | if (numericp(optarg)) | |
1004 | g = atoi(optarg); | |
1005 | else if ((gr = getgrnam(optarg)) == 0) | |
1006 | die(1, "unknown group `%s'", optarg); | |
1007 | else | |
1008 | g = gr->gr_gid; | |
1009 | break; | |
1010 | case 'U': | |
1011 | if (numericp(optarg)) | |
1012 | u = atoi(optarg); | |
1013 | else if ((pw = getpwnam(optarg)) == 0) | |
1014 | die(1, "unknown user `%s'", optarg); | |
1015 | else | |
1016 | u = pw->pw_uid; | |
1017 | break; | |
1018 | case 'p': | |
1019 | if (numericp(optarg)) | |
1020 | port = atoi(optarg); | |
1021 | else if ((s = getservbyname(optarg, "tcp")) == 0) | |
1022 | die(1, "unknown service name `%s'", optarg); | |
1023 | else | |
1024 | port = ntohs(s->s_port); | |
1025 | break; | |
1026 | default: f |= f_bogus; break; | |
1027 | } | |
1028 | } | |
1029 | if (optind < argc) f |= f_bogus; | |
1030 | if (f & f_bogus) { usage(stderr); exit(1); } | |
1031 | ||
1032 | /* If a user has been requested, but no group, then find the user's primary | |
1033 | * group. If the user was given by name, then we already have a password | |
1034 | * entry and should use that, in case two differently-named users have the | |
1035 | * same uid but distinct gids. | |
1036 | */ | |
1037 | if (u != -1 && g == -1) { | |
1038 | if (!pw && (pw = getpwuid(u)) == 0) { | |
1039 | die(1, "failed to find password entry for user %d: " | |
1040 | "request group explicitly", u); | |
1041 | } | |
1042 | g = pw->pw_gid; | |
1043 | } | |
1044 | ||
1045 | /* Initialize system-specific machinery. */ | |
b093b41d | 1046 | init_sys(); |
74716d82 MW |
1047 | |
1048 | /* Load the global policy rules. */ | |
1049 | fwatch_init(&polfw, policyfile); | |
1050 | if (load_policy_file(policyfile, &policy)) | |
9da480be | 1051 | exit(1); |
9da480be | 1052 | |
74716d82 | 1053 | /* Open the random data source. */ |
9da480be MW |
1054 | if ((randfd = open("/dev/urandom", O_RDONLY)) < 0) { |
1055 | die(1, "failed to open `/dev/urandom' for reading: %s", | |
1056 | strerror(errno)); | |
1057 | } | |
1058 | ||
74716d82 | 1059 | /* Set up the I/O event system. */ |
9da480be | 1060 | sel_init(&sel); |
74716d82 MW |
1061 | |
1062 | /* Watch for some interesting signals. */ | |
1063 | sig_init(&sel); | |
1064 | sig_add(&sigint, SIGINT, quit, "SIGINT"); | |
1065 | sig_add(&sigterm, SIGTERM, quit, "SIGTERM"); | |
1066 | ||
1067 | /* Listen for incoming connections. */ | |
bf4d9761 MW |
1068 | for (ao = addroptab; ao->name; ao++) |
1069 | if (!make_listening_socket(ao, port)) any = 1; | |
74716d82 MW |
1070 | if (!any) die(1, "no IP protocols supported"); |
1071 | ||
1072 | /* Open the pidfile now, in case it's somewhere we can't write. */ | |
1073 | if (pidfile && (fp = fopen(pidfile, "w")) == 0) { | |
1074 | die(1, "failed to open pidfile `%s' for writing: %s", | |
1075 | pidfile, strerror(errno)); | |
1076 | } | |
1077 | ||
1078 | /* If we're meant to use syslog, then open the log. */ | |
1079 | if (flags & F_SYSLOG) | |
1080 | openlog(QUIS, 0, LOG_DAEMON); | |
1081 | ||
1082 | /* Drop privileges. */ | |
1083 | if ((g != -1 && (setegid(g) || setgid(g) || | |
1084 | (getuid() == 0 && setgroups(1, &g)))) || | |
1085 | (u != -1 && setuid(u))) | |
1086 | die(1, "failed to drop privileges: %s", strerror(errno)); | |
9da480be | 1087 | |
74716d82 MW |
1088 | /* Become a background process, if requested. */ |
1089 | if ((f & f_daemon) && daemonize()) | |
1090 | die(1, "failed to become daemon: %s", strerror(errno)); | |
1091 | ||
1092 | /* Write the process id to the pidfile. */ | |
1093 | if (fp) { | |
1094 | fprintf(fp, "%d\n", getpid()); | |
1095 | fclose(fp); | |
1096 | } | |
1097 | ||
1098 | /* And now we're going. */ | |
1099 | flags |= F_RUNNING; | |
1100 | ||
1101 | /* Read events and process them. */ | |
1102 | for (;;) { | |
1103 | if (sel_select(&sel) && errno != EINTR) | |
1104 | die(1, "select failed: %s", strerror(errno)); | |
1105 | } | |
9da480be | 1106 | |
74716d82 | 1107 | /* This just keeps the compiler happy. */ |
9da480be MW |
1108 | return (0); |
1109 | } | |
1110 | ||
1111 | /*----- That's all, folks -------------------------------------------------*/ |