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 */ | |
223e3e2b | 58 | union addr raddr; /* Remote address */ |
c3794524 | 59 | struct query q; /* The clients query and our reply */ |
4f8fdcc1 | 60 | struct sel_timer t; /* Timeout for idle or doomed conn */ |
c3794524 MW |
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 | }; | |
65 | ||
66 | /* A proxy connection. */ | |
67 | struct proxy { | |
68 | int fd; /* Connection; -1 if in progress */ | |
69 | struct client *c; /* Back to the client */ | |
70 | conn cn; /* Nonblocking connection */ | |
71 | selbuf b; /* Accumulate the response line */ | |
72 | struct writebuf wb; /* Write buffer for query */ | |
73 | char nat[ADDRLEN]; /* Server address, as text */ | |
9da480be MW |
74 | }; |
75 | ||
76 | /*----- Static variables --------------------------------------------------*/ | |
77 | ||
c3794524 | 78 | static sel_state sel; /* I/O multiplexer state */ |
9da480be | 79 | |
74716d82 MW |
80 | static const char *pidfile = 0; /* Where to write daemon's pid */ |
81 | ||
82 | static const char *policyfile = POLICYFILE; /* Filename for global policy */ | |
c3794524 MW |
83 | static const struct policy default_policy = POLICY_INIT(A_NAME); |
84 | static policy_v policy = DA_INIT; /* Vector of global policy rules */ | |
85 | static fwatch polfw; /* Watch policy file for changes */ | |
9da480be | 86 | |
c3794524 MW |
87 | static unsigned char tokenbuf[4096]; /* Random-ish data for tokens */ |
88 | static size_t tokenptr = sizeof(tokenbuf); /* Current read position */ | |
89 | static int randfd; /* File descriptor for random data */ | |
9da480be | 90 | |
74716d82 MW |
91 | static unsigned flags = 0; /* Various interesting flags */ |
92 | #define F_SYSLOG 1u /* Use syslog for logging */ | |
93 | #define F_RUNNING 2u /* Running properly now */ | |
94 | ||
c3794524 | 95 | /*----- Ident protocol parsing --------------------------------------------*/ |
9da480be | 96 | |
c3794524 MW |
97 | /* Advance *PP over whitespace characters. */ |
98 | static void skipws(const char **pp) | |
99 | { while (isspace((unsigned char )**pp)) (*pp)++; } | |
100 | ||
101 | /* Copy a token of no more than N bytes starting at *PP into Q, advancing *PP | |
102 | * over it. | |
103 | */ | |
104 | static int idtoken(const char **pp, char *q, size_t n) | |
9da480be | 105 | { |
c3794524 | 106 | const char *p = *pp; |
9da480be | 107 | |
c3794524 MW |
108 | skipws(&p); |
109 | n--; | |
110 | for (;;) { | |
111 | if (*p == ':' || *p <= 32 || *p >= 127) break; | |
112 | if (!n) return (-1); | |
113 | *q++ = *p++; | |
114 | n--; | |
9da480be | 115 | } |
c3794524 MW |
116 | *q++ = 0; |
117 | *pp = p; | |
118 | return (0); | |
119 | } | |
120 | ||
121 | /* Read an unsigned decimal number from *PP, and store it in *II. Check that | |
122 | * it's between MIN and MAX, and advance *PP over it. Return zero for | |
123 | * success, or nonzero if something goes wrong. | |
124 | */ | |
125 | static int unum(const char **pp, unsigned *ii, unsigned min, unsigned max) | |
126 | { | |
127 | char *q; | |
128 | unsigned long i; | |
129 | int e; | |
130 | ||
131 | skipws(pp); | |
132 | if (!isdigit((unsigned char)**pp)) return (-1); | |
133 | e = errno; errno = 0; | |
134 | i = strtoul(*pp, &q, 10); | |
135 | if (errno) return (-1); | |
136 | *pp = q; | |
137 | errno = e; | |
138 | if (i < min || i > max) return (-1); | |
139 | *ii = i; | |
140 | return (0); | |
9da480be MW |
141 | } |
142 | ||
c3794524 MW |
143 | /*----- Asynchronous writing ----------------------------------------------*/ |
144 | ||
145 | /* Callback for actually writing stuff from a `writebuf'. */ | |
9da480be MW |
146 | static void write_out(int fd, unsigned mode, void *p) |
147 | { | |
148 | ssize_t n; | |
149 | struct writebuf *wb = p; | |
150 | ||
c3794524 | 151 | /* Try to write something. */ |
9da480be MW |
152 | if ((n = write(fd, wb->buf + wb->o, wb->n)) < 0) { |
153 | if (errno == EAGAIN || errno == EWOULDBLOCK) return; | |
154 | wb->n = 0; | |
155 | sel_rmfile(&wb->wr); | |
156 | wb->func(errno, wb->p); | |
157 | } | |
158 | wb->o += n; | |
159 | wb->n -= n; | |
c3794524 MW |
160 | |
161 | /* If there's nothing left then restore the buffer to its empty state. */ | |
9da480be MW |
162 | if (!wb->n) { |
163 | wb->o = 0; | |
164 | sel_rmfile(&wb->wr); | |
165 | wb->func(0, wb->p); | |
166 | } | |
167 | } | |
168 | ||
c3794524 | 169 | /* Queue N bytes starting at P to be written. */ |
9da480be MW |
170 | static int queue_write(struct writebuf *wb, const void *p, size_t n) |
171 | { | |
c3794524 | 172 | /* Maybe there's nothing to actually do. */ |
9da480be | 173 | if (!n) return (0); |
c3794524 MW |
174 | |
175 | /* Make sure it'll fit. */ | |
9da480be | 176 | if (wb->n - wb->o + n > WRBUFSZ) return (-1); |
c3794524 MW |
177 | |
178 | /* If there's anything there already, then make sure it's at the start of | |
179 | * the available space. | |
180 | */ | |
9da480be MW |
181 | if (wb->o) { |
182 | memmove(wb->buf, wb->buf + wb->o, wb->n); | |
183 | wb->o = 0; | |
184 | } | |
c3794524 MW |
185 | |
186 | /* If there's nothing currently there, then we're not requesting write | |
187 | * notifications, so set that up, and force an initial wake-up. | |
188 | */ | |
9da480be MW |
189 | if (!wb->n) { |
190 | sel_addfile(&wb->wr); | |
191 | sel_force(&wb->wr); | |
192 | } | |
c3794524 MW |
193 | |
194 | /* Copy the new material over. */ | |
195 | memcpy(wb->buf + wb->n, p, n); | |
9da480be | 196 | wb->n += n; |
c3794524 MW |
197 | |
198 | /* Done. */ | |
9da480be MW |
199 | return (0); |
200 | } | |
201 | ||
c3794524 | 202 | /* Release resources allocated to WB. */ |
9da480be MW |
203 | static void free_writebuf(struct writebuf *wb) |
204 | { if (wb->n) sel_rmfile(&wb->wr); } | |
205 | ||
c3794524 MW |
206 | /* Initialize a writebuf in *WB, writing to file descriptor FD. On |
207 | * completion, call FUNC, passing it P and an error indicator: either 0 for | |
208 | * success or an `errno' value on failure. | |
209 | */ | |
9da480be MW |
210 | static void init_writebuf(struct writebuf *wb, |
211 | int fd, void (*func)(int, void *), void *p) | |
212 | { | |
213 | sel_initfile(&sel, &wb->wr, fd, SEL_WRITE, write_out, wb); | |
214 | wb->func = func; | |
215 | wb->p = p; | |
216 | wb->n = wb->o = 0; | |
217 | } | |
218 | ||
c3794524 | 219 | /*----- General utilities -------------------------------------------------*/ |
9da480be | 220 | |
c3794524 MW |
221 | /* Format and log MSG somewhere sensible, at the syslog(3) priority PRIO. |
222 | * Prefix it with a description of the query Q, if non-null. | |
223 | */ | |
224 | void logmsg(const struct query *q, int prio, const char *msg, ...) | |
9da480be | 225 | { |
c3794524 MW |
226 | va_list ap; |
227 | dstr d = DSTR_INIT; | |
74716d82 MW |
228 | time_t t; |
229 | struct tm *tm; | |
230 | char buf[64]; | |
c3794524 MW |
231 | |
232 | va_start(ap, msg); | |
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 | va_end(ap); | |
74716d82 MW |
241 | |
242 | if (!(flags & F_RUNNING)) | |
243 | moan("%s", d.buf); | |
244 | else if (flags & F_SYSLOG) | |
245 | syslog(prio, "%s", d.buf); | |
246 | else { | |
247 | t = time(0); | |
248 | tm = localtime(&t); | |
249 | strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S %z", tm); | |
250 | fprintf(stderr, "%s %s: %s\n", buf, QUIS, d.buf); | |
251 | } | |
252 | ||
c3794524 | 253 | dstr_destroy(&d); |
9da480be MW |
254 | } |
255 | ||
c3794524 MW |
256 | /* Fix up a socket FD so that it won't bite us. Returns zero on success, or |
257 | * nonzero on error. | |
258 | */ | |
95df134c MW |
259 | static int fix_up_socket(int fd, const char *what) |
260 | { | |
261 | int yes = 1; | |
262 | ||
263 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { | |
264 | logmsg(0, LOG_ERR, "failed to set %s connection nonblocking: %s", | |
265 | what, strerror(errno)); | |
266 | return (-1); | |
267 | } | |
268 | ||
269 | if (setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &yes, sizeof(yes))) { | |
270 | logmsg(0, LOG_ERR, | |
271 | "failed to disable `out-of-band' data on %s connection: %s", | |
272 | what, strerror(errno)); | |
273 | return (-1); | |
274 | } | |
275 | ||
276 | return (0); | |
277 | } | |
278 | ||
c3794524 MW |
279 | /*----- Client output functions -------------------------------------------*/ |
280 | ||
281 | static void disconnect_client(struct client *c); | |
282 | ||
283 | /* Notification that output has been written. If successful, re-enable the | |
284 | * input buffer and prepare for another query. | |
285 | */ | |
9da480be MW |
286 | static void done_client_write(int err, void *p) |
287 | { | |
288 | struct client *c = p; | |
289 | ||
290 | if (!err) | |
291 | selbuf_enable(&c->b); | |
292 | else { | |
293 | logmsg(&c->q, LOG_ERR, "failed to send reply: %s", strerror(err)); | |
294 | disconnect_client(c); | |
295 | } | |
296 | } | |
297 | ||
c3794524 MW |
298 | /* Format the message FMT and queue it to be sent to the client. Client |
299 | * input will be disabled until the write completes. | |
300 | */ | |
9da480be MW |
301 | static void write_to_client(struct client *c, const char *fmt, ...) |
302 | { | |
303 | va_list ap; | |
304 | char buf[WRBUFSZ]; | |
305 | ssize_t n; | |
306 | ||
307 | va_start(ap, fmt); | |
308 | n = vsnprintf(buf, sizeof(buf), fmt, ap); | |
309 | if (n < 0) { | |
310 | logmsg(&c->q, LOG_ERR, "failed to format output: %s", strerror(errno)); | |
311 | disconnect_client(c); | |
312 | return; | |
313 | } else if (n > sizeof(buf)) { | |
314 | logmsg(&c->q, LOG_ERR, "output too long for client send buffer"); | |
315 | disconnect_client(c); | |
316 | return; | |
317 | } | |
318 | ||
319 | selbuf_disable(&c->b); | |
320 | if (queue_write(&c->wb, buf, n)) { | |
321 | logmsg(&c->q, LOG_ERR, "write buffer overflow"); | |
322 | disconnect_client(c); | |
323 | } | |
324 | } | |
325 | ||
c3794524 MW |
326 | /* Format a reply to the client, with the form LPORT:RPORT:TY:TOK0[:TOK1]. |
327 | * Typically, TY will be `ERROR' or `USERID'. In the former case, TOK0 will | |
328 | * be the error token and TOK1 will be null; in the latter case, TOK0 will be | |
329 | * the operating system and TOK1 the user name. | |
330 | */ | |
c809f908 MW |
331 | static void reply(struct client *c, const char *ty, |
332 | const char *tok0, const char *tok1) | |
9da480be | 333 | { |
c809f908 MW |
334 | write_to_client(c, "%u,%u:%s:%s%s%s\r\n", |
335 | c->q.s[L].port, c->q.s[R].port, ty, | |
336 | tok0, tok1 ? ":" : "", tok1 ? tok1 : ""); | |
9da480be MW |
337 | } |
338 | ||
c3794524 | 339 | /* Mapping from error codes to their protocol tokens. */ |
bf4d9761 MW |
340 | const char *const errtok[] = { |
341 | #define DEFTOK(err, tok) tok, | |
342 | ERROR(DEFTOK) | |
343 | #undef DEFTOK | |
344 | }; | |
345 | ||
c3794524 | 346 | /* Report an error with code ERR to the client. */ |
9da480be MW |
347 | static void reply_error(struct client *c, unsigned err) |
348 | { | |
349 | assert(err < E_LIMIT); | |
c809f908 | 350 | reply(c, "ERROR", errtok[err], 0); |
9da480be MW |
351 | } |
352 | ||
c3794524 | 353 | /*----- NAT proxy functions -----------------------------------------------*/ |
9da480be | 354 | |
c3794524 MW |
355 | /* Cancel the proxy operation PX, closing the connection and releasing |
356 | * resources. This is used for both normal and unexpected closures. | |
357 | */ | |
358 | static void cancel_proxy(struct proxy *px) | |
9da480be | 359 | { |
c3794524 MW |
360 | if (px->fd == -1) |
361 | conn_kill(&px->cn); | |
362 | else { | |
363 | close(px->fd); | |
364 | selbuf_destroy(&px->b); | |
365 | free_writebuf(&px->wb); | |
9da480be | 366 | } |
c3794524 MW |
367 | selbuf_enable(&px->c->b); |
368 | px->c->px = 0; | |
369 | xfree(px); | |
9da480be MW |
370 | } |
371 | ||
c3794524 MW |
372 | /* Notification that a line (presumably a reply) has been received from the |
373 | * server. We should check it, log it, and propagate the answer back. | |
374 | * Whatever happens, this proxy operation is now complete. | |
375 | */ | |
9da480be MW |
376 | static void proxy_line(char *line, size_t sz, void *p) |
377 | { | |
378 | struct proxy *px = p; | |
379 | char buf[1024]; | |
380 | const char *q = line; | |
381 | unsigned lp, rp; | |
382 | ||
c3794524 | 383 | /* Trim trailing space. */ |
9da480be | 384 | while (sz && isspace((unsigned char)line[sz - 1])) sz--; |
9da480be | 385 | |
c3794524 | 386 | /* Parse the port numbers. These should match the request. */ |
9da480be MW |
387 | if (unum(&q, &lp, 1, 65535)) goto syntax; |
388 | skipws(&q); if (*q != ',') goto syntax; q++; | |
389 | if (unum(&q, &rp, 1, 65535)) goto syntax; | |
390 | skipws(&q); if (*q != ':') goto syntax; q++; | |
391 | if (lp != px->c->q.u.nat.port || rp != px->c->q.s[R].port) goto syntax; | |
c3794524 MW |
392 | |
393 | /* Find out what kind of reply this is. */ | |
9da480be MW |
394 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
395 | skipws(&q); if (*q != ':') goto syntax; q++; | |
c3794524 | 396 | |
9da480be | 397 | if (strcmp(buf, "ERROR") == 0) { |
c3794524 MW |
398 | |
399 | /* Report the error without interpreting it. It might be meaningful to | |
400 | * the client. | |
401 | */ | |
9da480be MW |
402 | skipws(&q); |
403 | logmsg(&px->c->q, LOG_ERR, "proxy error from %s: %s", px->nat, q); | |
c809f908 | 404 | reply(px->c, "ERROR", q, 0); |
c3794524 | 405 | |
9da480be | 406 | } else if (strcmp(buf, "USERID") == 0) { |
c3794524 MW |
407 | |
408 | /* Parse out the operating system and user name, and pass them on. */ | |
9da480be MW |
409 | if (idtoken(&q, buf, sizeof(buf))) goto syntax; |
410 | skipws(&q); if (*q != ':') goto syntax; q++; | |
411 | skipws(&q); | |
412 | logmsg(&px->c->q, LOG_ERR, "user `%s'; proxy = %s, os = %s", | |
413 | q, px->nat, buf); | |
c809f908 | 414 | reply(px->c, "USERID", buf, q); |
c3794524 | 415 | |
9da480be MW |
416 | } else |
417 | goto syntax; | |
418 | goto done; | |
419 | ||
420 | syntax: | |
c3794524 | 421 | /* We didn't understand the message from the client. */ |
9da480be MW |
422 | logmsg(&px->c->q, LOG_ERR, "failed to parse response from %s", px->nat); |
423 | reply_error(px->c, E_UNKNOWN); | |
424 | done: | |
c3794524 | 425 | /* All finished, no matter what. */ |
9da480be MW |
426 | cancel_proxy(px); |
427 | } | |
428 | ||
c3794524 MW |
429 | /* Notification that we have written the query to the server. Await a |
430 | * response if successful. | |
431 | */ | |
9da480be MW |
432 | static void done_proxy_write(int err, void *p) |
433 | { | |
434 | struct proxy *px = p; | |
435 | ||
436 | if (err) { | |
437 | logmsg(&px->c->q, LOG_ERR, "failed to proxy query to %s: %s", | |
438 | px->nat, strerror(errno)); | |
439 | reply_error(px->c, E_UNKNOWN); | |
440 | cancel_proxy(px); | |
441 | return; | |
442 | } | |
443 | selbuf_enable(&px->b); | |
444 | } | |
445 | ||
c3794524 MW |
446 | /* Notification that the connection to the server is either established or |
447 | * failed. In the former case, queue the right query. | |
448 | */ | |
9da480be MW |
449 | static void proxy_connected(int fd, void *p) |
450 | { | |
451 | struct proxy *px = p; | |
452 | char buf[16]; | |
453 | int n; | |
454 | ||
c3794524 | 455 | /* If the connection failed then report the problem and give up. */ |
9da480be MW |
456 | if (fd < 0) { |
457 | logmsg(&px->c->q, LOG_ERR, | |
458 | "failed to make %s proxy connection to %s: %s", | |
bf4d9761 | 459 | px->c->l->ao->name, px->nat, strerror(errno)); |
9da480be MW |
460 | reply_error(px->c, E_UNKNOWN); |
461 | cancel_proxy(px); | |
462 | return; | |
463 | } | |
464 | ||
c3794524 | 465 | /* We're now ready to go, so set things up. */ |
9da480be MW |
466 | px->fd = fd; |
467 | selbuf_init(&px->b, &sel, fd, proxy_line, px); | |
468 | selbuf_setsize(&px->b, 1024); | |
469 | selbuf_disable(&px->b); | |
470 | init_writebuf(&px->wb, fd, done_proxy_write, px); | |
471 | ||
c3794524 MW |
472 | /* Write the query. This buffer is large enough because we've already |
473 | * range-checked the remote the port number and the local one came from the | |
474 | * kernel, which we trust not to do anything stupid. | |
475 | */ | |
9da480be MW |
476 | n = sprintf(buf, "%u,%u\r\n", px->c->q.u.nat.port, px->c->q.s[R].port); |
477 | queue_write(&px->wb, buf, n); | |
478 | } | |
479 | ||
c3794524 MW |
480 | /* Proxy the query through to a client machine for which we're providing NAT |
481 | * disservice. | |
482 | */ | |
9da480be MW |
483 | static void proxy_query(struct client *c) |
484 | { | |
485 | struct socket s; | |
486 | struct sockaddr_storage ss; | |
487 | size_t ssz; | |
488 | struct proxy *px; | |
9da480be MW |
489 | int fd; |
490 | ||
c3794524 | 491 | /* Allocate the context structure for the NAT. */ |
9da480be | 492 | px = xmalloc(sizeof(*px)); |
c3794524 MW |
493 | |
494 | /* We'll use the client host's address in lots of log messages, so we may | |
495 | * as well format it once and use it over and over. | |
496 | */ | |
bf4d9761 | 497 | inet_ntop(c->q.ao->af, &c->q.u.nat.addr, px->nat, sizeof(px->nat)); |
9da480be | 498 | |
c3794524 | 499 | /* Create the socket for the connection. */ |
bf4d9761 | 500 | if ((fd = socket(c->q.ao->af, SOCK_STREAM, 0)) < 0) { |
9da480be | 501 | logmsg(&c->q, LOG_ERR, "failed to make %s socket for proxy: %s", |
bf4d9761 | 502 | c->l->ao->name, strerror(errno)); |
9da480be MW |
503 | goto err_0; |
504 | } | |
95df134c | 505 | if (fix_up_socket(fd, "proxy")) goto err_1; |
9da480be | 506 | |
c3794524 MW |
507 | /* Set up the connection to the client host. The connection interface is a |
508 | * bit broken: if the connection completes immediately, then the callback | |
509 | * function is called synchronously, and that might decide to shut | |
510 | * everything down. So we must have fully initialized our context before | |
511 | * calling `conn_init', and mustn't touch it again afterwards -- since the | |
512 | * block may have been freed. | |
513 | */ | |
9da480be MW |
514 | s = c->q.u.nat; |
515 | s.port = 113; | |
bf4d9761 | 516 | c->l->ao->socket_to_sockaddr(&s, &ss, &ssz); |
9da480be | 517 | selbuf_disable(&c->b); |
79805e61 MW |
518 | c->px = px; px->c = c; |
519 | px->fd = -1; | |
9da480be MW |
520 | if (conn_init(&px->cn, &sel, fd, (struct sockaddr *)&ss, ssz, |
521 | proxy_connected, px)) { | |
522 | logmsg(&c->q, LOG_ERR, "failed to make %s proxy connection to %s: %s", | |
bf4d9761 | 523 | c->l->ao->name, px->nat, strerror(errno)); |
9da480be MW |
524 | goto err_2; |
525 | } | |
526 | ||
c3794524 | 527 | /* All ready to go. */ |
9da480be MW |
528 | return; |
529 | ||
c3794524 | 530 | /* Tidy up after various kinds of failures. */ |
9da480be MW |
531 | err_2: |
532 | selbuf_enable(&c->b); | |
533 | err_1: | |
534 | close(px->fd); | |
535 | err_0: | |
536 | xfree(px); | |
537 | reply_error(c, E_UNKNOWN); | |
538 | } | |
539 | ||
c3794524 MW |
540 | /*----- Client connection functions ---------------------------------------*/ |
541 | ||
542 | /* Disconnect a client, freeing up any associated resources. */ | |
543 | static void disconnect_client(struct client *c) | |
544 | { | |
545 | close(c->fd); | |
546 | selbuf_destroy(&c->b); | |
4f8fdcc1 | 547 | sel_rmtimer(&c->t); |
c3794524 MW |
548 | free_writebuf(&c->wb); |
549 | if (c->px) cancel_proxy(c->px); | |
550 | xfree(c); | |
551 | } | |
9da480be | 552 | |
4f8fdcc1 MW |
553 | /* Time out a client because it's been idle for too long. */ |
554 | static void timeout_client(struct timeval *tv, void *p) | |
555 | { | |
556 | struct client *c = p; | |
557 | logmsg(&c->q, LOG_NOTICE, "timing out idle or stuck client"); | |
558 | sel_addtimer(&sel, &c->t, tv, timeout_client, 0); | |
559 | disconnect_client(c); | |
560 | } | |
561 | ||
562 | /* Reset the client idle timer, as a result of activity. Set EXISTP if | |
563 | * there is an existing timer which needs to be removed. | |
564 | */ | |
565 | static void reset_client_timer(struct client *c, int existp) | |
566 | { | |
567 | struct timeval tv; | |
568 | ||
569 | gettimeofday(&tv, 0); | |
570 | tv.tv_sec += 30; | |
571 | if (existp) sel_rmtimer(&c->t); | |
572 | sel_addtimer(&sel, &c->t, &tv, timeout_client, c); | |
573 | } | |
574 | ||
c3794524 MW |
575 | /* Write a pseudorandom token into the buffer at P, which must have space for |
576 | * at least TOKENSZ bytes. | |
577 | */ | |
578 | #define TOKENRANDSZ 8 | |
579 | #define TOKENSZ ((4*TOKENRANDSZ + 5)/3) | |
9da480be MW |
580 | static void user_token(char *p) |
581 | { | |
9da480be MW |
582 | unsigned a = 0; |
583 | unsigned b = 0; | |
584 | int i; | |
c3794524 MW |
585 | static const char tokmap[64] = |
586 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-"; | |
9da480be | 587 | |
c3794524 MW |
588 | /* If there's not enough pseudorandom stuff lying around, then read more |
589 | * from the kernel. | |
590 | */ | |
591 | if (tokenptr + TOKENRANDSZ >= sizeof(tokenbuf)) { | |
9da480be MW |
592 | if (read(randfd, tokenbuf, sizeof(tokenbuf)) < sizeof(tokenbuf)) |
593 | die(1, "unexpected short read or error from `/dev/urandom'"); | |
594 | tokenptr = 0; | |
595 | } | |
596 | ||
c3794524 MW |
597 | /* Now encode the bytes using a slightly tweaked base-64 encoding. Read |
598 | * bytes into the accumulator and write out characters while there's | |
599 | * enough material. | |
600 | */ | |
601 | for (i = 0; i < TOKENRANDSZ; i++) { | |
9da480be MW |
602 | a = (a << 8) | tokenbuf[tokenptr++]; b += 8; |
603 | while (b >= 6) { | |
604 | b -= 6; | |
605 | *p++ = tokmap[(a >> b) & 0x3f]; | |
606 | } | |
607 | } | |
c3794524 MW |
608 | |
609 | /* If there's anything left in the accumulator then flush it out. */ | |
9da480be MW |
610 | if (b) |
611 | *p++ = tokmap[(a << (6 - b)) & 0x3f]; | |
c3794524 MW |
612 | |
613 | /* Null-terminate the token. */ | |
9da480be MW |
614 | *p++ = 0; |
615 | } | |
616 | ||
c3794524 MW |
617 | /* Notification that a line has been received from the client. Parse it, |
618 | * find out about the connection it's referring to, apply the relevant | |
619 | * policy rules, and produce a response. This is where almost everything | |
620 | * interesting happens. | |
621 | */ | |
9da480be MW |
622 | static void client_line(char *line, size_t len, void *p) |
623 | { | |
624 | struct client *c = p; | |
625 | const char *q; | |
626 | struct passwd *pw = 0; | |
627 | const struct policy *pol; | |
628 | dstr d = DSTR_INIT; | |
629 | struct policy upol = POLICY_INIT(A_LIMIT); | |
630 | struct policy_file pf; | |
631 | char buf[16]; | |
632 | int i; | |
633 | ||
c3794524 | 634 | /* If the connection has closed, then tidy stuff away. */ |
9da480be MW |
635 | c->q.s[L].port = c->q.s[R].port = 0; |
636 | if (!line) { | |
637 | disconnect_client(c); | |
638 | return; | |
639 | } | |
640 | ||
4f8fdcc1 MW |
641 | /* Client activity, so update the timer. */ |
642 | reset_client_timer(c, 1); | |
643 | ||
c3794524 MW |
644 | /* See if the policy file has changed since we last looked. If so, try to |
645 | * read the new version. | |
646 | */ | |
74716d82 MW |
647 | if (fwatch_update(&polfw, policyfile)) { |
648 | logmsg(0, LOG_INFO, "reload master policy file `%s'", policyfile); | |
649 | load_policy_file(policyfile, &policy); | |
9da480be MW |
650 | } |
651 | ||
c3794524 | 652 | /* Read the local and remote port numbers into the query structure. */ |
9da480be MW |
653 | q = line; |
654 | if (unum(&q, &c->q.s[L].port, 1, 65535)) goto bad; | |
655 | skipws(&q); if (*q != ',') goto bad; q++; | |
656 | if (unum(&q, &c->q.s[R].port, 1, 65535)) goto bad; | |
657 | skipws(&q); if (*q) goto bad; | |
658 | ||
c3794524 | 659 | /* Identify the connection. Act on the result. */ |
223e3e2b | 660 | c->q.s[R].addr = c->raddr; |
9da480be MW |
661 | identify(&c->q); |
662 | switch (c->q.resp) { | |
c3794524 | 663 | |
9da480be | 664 | case R_UID: |
c3794524 MW |
665 | /* We found a user. Track down the user's password entry, because |
666 | * we'll want that later. Most of the processing for this case is | |
667 | * below. | |
668 | */ | |
9da480be MW |
669 | if ((pw = getpwuid(c->q.u.uid)) == 0) { |
670 | logmsg(&c->q, LOG_ERR, "no passwd entry for user %d", c->q.u.uid); | |
671 | reply_error(c, E_NOUSER); | |
672 | return; | |
673 | } | |
674 | break; | |
c3794524 | 675 | |
9da480be | 676 | case R_NAT: |
c3794524 MW |
677 | /* We've acted as a NAT for this connection. Proxy the query through |
678 | * to the actal client host. | |
679 | */ | |
9da480be MW |
680 | proxy_query(c); |
681 | return; | |
c3794524 | 682 | |
9da480be | 683 | case R_ERROR: |
c3794524 MW |
684 | /* We failed to identify the connection for some reason. We should |
685 | * already have logged an error, so there's not much to do here. | |
686 | */ | |
9da480be MW |
687 | reply_error(c, c->q.u.error); |
688 | return; | |
c3794524 | 689 | |
9da480be | 690 | default: |
c3794524 | 691 | /* Something happened that we don't understand. */ |
9da480be MW |
692 | abort(); |
693 | } | |
694 | ||
c3794524 | 695 | /* Search the table of policy rules to find a match. */ |
9da480be MW |
696 | for (i = 0; i < DA_LEN(&policy); i++) { |
697 | pol = &DA(&policy)[i]; | |
698 | if (!match_policy(pol, &c->q)) continue; | |
c3794524 MW |
699 | |
700 | /* If this is something simple, then apply the resulting policy rule. */ | |
701 | if (pol->act.act != A_USER) goto match; | |
702 | ||
703 | /* The global policy has decided to let the user have a say, so we must | |
704 | * parse the user file. | |
705 | */ | |
9da480be MW |
706 | DRESET(&d); |
707 | dstr_putf(&d, "%s/.yaid.policy", pw->pw_dir); | |
708 | if (open_policy_file(&pf, d.buf, "user policy file", &c->q)) | |
709 | continue; | |
710 | while (!read_policy_file(&pf)) { | |
c3794524 MW |
711 | |
712 | /* Give up after 100 lines. If the user's policy is that complicated, | |
713 | * something's gone very wrong. Or there's too much commentary or | |
714 | * something. | |
715 | */ | |
9da480be MW |
716 | if (pf.lno > 100) { |
717 | logmsg(&c->q, LOG_ERR, "%s:%d: user policy file too long", | |
718 | pf.name, pf.lno); | |
719 | break; | |
720 | } | |
c3794524 MW |
721 | |
722 | /* If this isn't a match, go around for the next rule. */ | |
9da480be | 723 | if (!match_policy(&pf.p, &c->q)) continue; |
c3794524 MW |
724 | |
725 | /* Check that the user is allowed to request this action. If not, see | |
726 | * if there's a more acceptable action later on. | |
727 | */ | |
9da480be MW |
728 | if (!(pol->act.u.user & (1 << pf.p.act.act))) { |
729 | logmsg(&c->q, LOG_ERR, | |
730 | "%s:%d: user action forbidden by global policy", | |
731 | pf.name, pf.lno); | |
732 | continue; | |
733 | } | |
c3794524 MW |
734 | |
735 | /* We've found a match, so grab it, close the file, and say we're | |
736 | * done. | |
737 | */ | |
9da480be MW |
738 | upol = pf.p; pol = &upol; |
739 | init_policy(&pf.p); | |
740 | close_policy_file(&pf); | |
c3794524 | 741 | DDESTROY(&d); |
9da480be MW |
742 | goto match; |
743 | } | |
744 | close_policy_file(&pf); | |
c3794524 | 745 | DDESTROY(&d); |
9da480be | 746 | } |
c3794524 MW |
747 | |
748 | /* No match: apply the built-in default policy. */ | |
9da480be MW |
749 | pol = &default_policy; |
750 | ||
751 | match: | |
9da480be | 752 | switch (pol->act.act) { |
c3794524 | 753 | |
9da480be | 754 | case A_NAME: |
c3794524 | 755 | /* Report the actual user's name. */ |
9da480be | 756 | logmsg(&c->q, LOG_INFO, "user `%s' (%d)", pw->pw_name, c->q.u.uid); |
c809f908 | 757 | reply(c, "USERID", "UNIX", pw->pw_name); |
9da480be | 758 | break; |
c3794524 | 759 | |
9da480be | 760 | case A_TOKEN: |
c3794524 | 761 | /* Report an arbitrary token which we can look up in our log file. */ |
9da480be MW |
762 | user_token(buf); |
763 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); token = %s", | |
764 | pw->pw_name, c->q.u.uid, buf); | |
c809f908 | 765 | reply(c, "USERID", "OTHER", buf); |
9da480be | 766 | break; |
c3794524 | 767 | |
9da480be | 768 | case A_DENY: |
c3794524 | 769 | /* Deny that there's anyone there at all. */ |
9da480be MW |
770 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); denying", |
771 | pw->pw_name, c->q.u.uid); | |
772 | break; | |
c3794524 | 773 | |
9da480be | 774 | case A_HIDE: |
c3794524 | 775 | /* Report the user as being hidden. */ |
9da480be MW |
776 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); hiding", |
777 | pw->pw_name, c->q.u.uid); | |
778 | reply_error(c, E_HIDDEN); | |
779 | break; | |
c3794524 | 780 | |
9da480be | 781 | case A_LIE: |
c3794524 | 782 | /* Tell an egregious lie about who the user is. */ |
9da480be MW |
783 | logmsg(&c->q, LOG_INFO, "user `%s' (%d); lie = `%s'", |
784 | pw->pw_name, c->q.u.uid, pol->act.u.lie); | |
c809f908 | 785 | reply(c, "USERID", "UNIX", pol->act.u.lie); |
9da480be | 786 | break; |
c3794524 | 787 | |
9da480be | 788 | default: |
c3794524 | 789 | /* Something has gone very wrong. */ |
9da480be MW |
790 | abort(); |
791 | } | |
792 | ||
c3794524 | 793 | /* All done. */ |
9da480be MW |
794 | free_policy(&upol); |
795 | return; | |
796 | ||
797 | bad: | |
798 | logmsg(&c->q, LOG_ERR, "failed to parse query from client"); | |
799 | disconnect_client(c); | |
800 | } | |
801 | ||
c3794524 | 802 | /* Notification that a new client has connected. Prepare to read a query. */ |
9da480be MW |
803 | static void accept_client(int fd, unsigned mode, void *p) |
804 | { | |
805 | struct listen *l = p; | |
806 | struct client *c; | |
807 | struct sockaddr_storage ssr, ssl; | |
808 | size_t ssz = sizeof(ssr); | |
809 | int sk; | |
810 | ||
c3794524 | 811 | /* Accept the new connection. */ |
9da480be MW |
812 | if ((sk = accept(fd, (struct sockaddr *)&ssr, &ssz)) < 0) { |
813 | if (errno != EAGAIN && errno == EWOULDBLOCK) { | |
814 | logmsg(0, LOG_ERR, "failed to accept incoming %s connection: %s", | |
bf4d9761 | 815 | l->ao->name, strerror(errno)); |
9da480be MW |
816 | } |
817 | return; | |
818 | } | |
95df134c | 819 | if (fix_up_socket(sk, "incoming client")) { close(sk); return; } |
9da480be | 820 | |
c3794524 | 821 | /* Build a client block and fill it in. */ |
9da480be MW |
822 | c = xmalloc(sizeof(*c)); |
823 | c->l = l; | |
bf4d9761 | 824 | c->q.ao = l->ao; |
c3794524 MW |
825 | |
826 | /* Collect the local and remote addresses. */ | |
223e3e2b | 827 | l->ao->sockaddr_to_addr(&ssr, &c->raddr); |
9da480be MW |
828 | ssz = sizeof(ssl); |
829 | if (getsockname(sk, (struct sockaddr *)&ssl, &ssz)) { | |
830 | logmsg(0, LOG_ERR, | |
831 | "failed to read local address for incoming %s connection: %s", | |
bf4d9761 | 832 | l->ao->name, strerror(errno)); |
9da480be MW |
833 | close(sk); |
834 | xfree(c); | |
835 | return; | |
836 | } | |
bf4d9761 | 837 | l->ao->sockaddr_to_addr(&ssl, &c->q.s[L].addr); |
9da480be MW |
838 | c->q.s[L].port = c->q.s[R].port = 0; |
839 | ||
c3794524 | 840 | /* Set stuff up for reading the query and sending responses. */ |
9da480be MW |
841 | selbuf_init(&c->b, &sel, sk, client_line, c); |
842 | selbuf_setsize(&c->b, 1024); | |
4f8fdcc1 | 843 | reset_client_timer(c, 0); |
9da480be MW |
844 | c->fd = sk; |
845 | c->px = 0; | |
846 | init_writebuf(&c->wb, sk, done_client_write, c); | |
847 | } | |
848 | ||
c3794524 MW |
849 | /*----- Main code ---------------------------------------------------------*/ |
850 | ||
851 | /* Set up a listening socket for the address family described by AO, | |
852 | * listening on PORT. | |
853 | */ | |
bf4d9761 | 854 | static int make_listening_socket(const struct addrops *ao, int port) |
9da480be MW |
855 | { |
856 | int fd; | |
bf4d9761 MW |
857 | int yes = 1; |
858 | struct socket s; | |
9da480be MW |
859 | struct sockaddr_storage ss; |
860 | struct listen *l; | |
861 | size_t ssz; | |
862 | ||
c3794524 | 863 | /* Make the socket. */ |
bf4d9761 | 864 | if ((fd = socket(ao->af, SOCK_STREAM, 0)) < 0) { |
a20696ca | 865 | if (errno == EAFNOSUPPORT) return (-1); |
9da480be | 866 | die(1, "failed to create %s listening socket: %s", |
bf4d9761 | 867 | ao->name, strerror(errno)); |
9da480be | 868 | } |
c3794524 MW |
869 | |
870 | /* Build the appropriate local address. */ | |
bf4d9761 MW |
871 | s.addr = *ao->any; |
872 | s.port = port; | |
873 | ao->socket_to_sockaddr(&s, &ss, &ssz); | |
c3794524 MW |
874 | |
875 | /* Perform any initialization specific to the address type. */ | |
bf4d9761 MW |
876 | if (ao->init_listen_socket(fd)) { |
877 | die(1, "failed to initialize %s listening socket: %s", | |
878 | ao->name, strerror(errno)); | |
879 | } | |
c3794524 MW |
880 | |
881 | /* Bind to the address. */ | |
882 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)); | |
bf4d9761 MW |
883 | if (bind(fd, (struct sockaddr *)&ss, ssz)) { |
884 | die(1, "failed to bind %s listening socket: %s", | |
885 | ao->name, strerror(errno)); | |
9da480be | 886 | } |
c3794524 MW |
887 | |
888 | /* Avoid unpleasant race conditions. */ | |
bf4d9761 | 889 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)) { |
9da480be | 890 | die(1, "failed to set %s listening socket nonblocking: %s", |
bf4d9761 | 891 | ao->name, strerror(errno)); |
9da480be | 892 | } |
c3794524 MW |
893 | |
894 | /* Prepare to listen. */ | |
9da480be | 895 | if (listen(fd, 5)) |
bf4d9761 | 896 | die(1, "failed to listen for %s: %s", ao->name, strerror(errno)); |
9da480be | 897 | |
c3794524 | 898 | /* Make a record of all of this. */ |
9da480be | 899 | l = xmalloc(sizeof(*l)); |
bf4d9761 | 900 | l->ao = ao; |
9da480be MW |
901 | sel_initfile(&sel, &l->f, fd, SEL_READ, accept_client, l); |
902 | sel_addfile(&l->f); | |
903 | ||
c3794524 | 904 | /* Done. */ |
a20696ca | 905 | return (0); |
9da480be MW |
906 | } |
907 | ||
74716d82 MW |
908 | /* Quit because of a fatal signal. */ |
909 | static void quit(int sig, void *p) | |
910 | { | |
911 | const char *signame = p; | |
912 | ||
913 | logmsg(0, LOG_NOTICE, "shutting down on %s", signame); | |
914 | if (pidfile) unlink(pidfile); | |
915 | exit(0); | |
916 | } | |
917 | ||
918 | /* Answer whether the string pointed to by P consists entirely of digits. */ | |
919 | static int numericp(const char *p) | |
920 | { | |
921 | while (*p) | |
922 | if (!isdigit((unsigned char)*p++)) return (0); | |
923 | return (1); | |
924 | } | |
925 | ||
926 | static void usage(FILE *fp) | |
927 | { | |
928 | pquis(fp, "Usage: $ [-Dl] [-G GROUP] [-U USER] [-P FILE] " | |
929 | "[-c FILE] [-p PORT]\n"); | |
930 | } | |
931 | ||
932 | static void version(FILE *fp) | |
933 | { pquis(fp, "$, version " VERSION "\n"); } | |
934 | ||
935 | static void help(FILE *fp) | |
936 | { | |
937 | version(fp); fputc('\n', fp); | |
938 | usage(fp); | |
939 | fputs("\n\ | |
940 | Yet Another Ident Daemon. Really, the world doesn't need such a thing.\n\ | |
941 | It's just a shame none of the others do the right things.\n\ | |
942 | \n\ | |
943 | Options:\n\ | |
944 | \n\ | |
945 | -h, --help Show this help message.\n\ | |
946 | -v, --version Show the version number.\n\ | |
947 | -u, --usage Show a very short usage summary.\n\ | |
948 | \n\ | |
949 | -D, --daemon Become a daemon, running in the background.\n\ | |
950 | -G, --group=GROUP Set group after initialization.\n\ | |
951 | -P, --pidfile=FILE Write process id to FILE.\n\ | |
952 | -U, --user=USER Set user after initialization.\n\ | |
953 | -c, --config=FILE Read global policy from FILE.\n\ | |
954 | -l, --syslog Write log messages using syslog(3).\n\ | |
955 | -p, --port=PORT Listen for connections on this port.\n", | |
956 | fp); | |
957 | } | |
958 | ||
9da480be MW |
959 | int main(int argc, char *argv[]) |
960 | { | |
961 | int port = 113; | |
74716d82 MW |
962 | uid_t u = -1; |
963 | gid_t g = -1; | |
964 | struct passwd *pw = 0; | |
965 | struct group *gr; | |
966 | struct servent *s; | |
967 | sig sigint, sigterm; | |
968 | FILE *fp = 0; | |
969 | int i; | |
970 | unsigned f = 0; | |
971 | #define f_bogus 1u | |
972 | #define f_daemon 2u | |
bf4d9761 MW |
973 | const struct addrops *ao; |
974 | int any = 0; | |
9da480be MW |
975 | |
976 | ego(argv[0]); | |
977 | ||
74716d82 MW |
978 | /* Parse command-line options. */ |
979 | for (;;) { | |
980 | const struct option opts[] = { | |
981 | { "help", 0, 0, 'h' }, | |
982 | { "version", 0, 0, 'v' }, | |
983 | { "usage", 0, 0, 'u' }, | |
984 | { "daemon", 0, 0, 'D' }, | |
985 | { "group", OPTF_ARGREQ, 0, 'G' }, | |
986 | { "pidfile", OPTF_ARGREQ, 0, 'P' }, | |
987 | { "user", OPTF_ARGREQ, 0, 'U' }, | |
988 | { "config", OPTF_ARGREQ, 0, 'c' }, | |
989 | { "syslog", 0, 0, 'l' }, | |
990 | { "port", OPTF_ARGREQ, 0, 'p' }, | |
991 | { 0, 0, 0, 0 } | |
992 | }; | |
993 | ||
994 | if ((i = mdwopt(argc, argv, "hvuDG:P:U:c:lp:", opts, 0, 0, 0)) < 0) | |
995 | break; | |
996 | switch (i) { | |
997 | case 'h': help(stdout); exit(0); | |
998 | case 'v': version(stdout); exit(0); | |
999 | case 'u': usage(stdout); exit(0); | |
1000 | case 'D': f |= f_daemon; break; | |
1001 | case 'P': pidfile = optarg; break; | |
1002 | case 'c': policyfile = optarg; break; | |
1003 | case 'l': flags |= F_SYSLOG; break; | |
1004 | case 'G': | |
1005 | if (numericp(optarg)) | |
1006 | g = atoi(optarg); | |
1007 | else if ((gr = getgrnam(optarg)) == 0) | |
1008 | die(1, "unknown group `%s'", optarg); | |
1009 | else | |
1010 | g = gr->gr_gid; | |
1011 | break; | |
1012 | case 'U': | |
1013 | if (numericp(optarg)) | |
1014 | u = atoi(optarg); | |
1015 | else if ((pw = getpwnam(optarg)) == 0) | |
1016 | die(1, "unknown user `%s'", optarg); | |
1017 | else | |
1018 | u = pw->pw_uid; | |
1019 | break; | |
1020 | case 'p': | |
1021 | if (numericp(optarg)) | |
1022 | port = atoi(optarg); | |
1023 | else if ((s = getservbyname(optarg, "tcp")) == 0) | |
1024 | die(1, "unknown service name `%s'", optarg); | |
1025 | else | |
1026 | port = ntohs(s->s_port); | |
1027 | break; | |
1028 | default: f |= f_bogus; break; | |
1029 | } | |
1030 | } | |
1031 | if (optind < argc) f |= f_bogus; | |
1032 | if (f & f_bogus) { usage(stderr); exit(1); } | |
1033 | ||
1034 | /* If a user has been requested, but no group, then find the user's primary | |
1035 | * group. If the user was given by name, then we already have a password | |
1036 | * entry and should use that, in case two differently-named users have the | |
1037 | * same uid but distinct gids. | |
1038 | */ | |
1039 | if (u != -1 && g == -1) { | |
1040 | if (!pw && (pw = getpwuid(u)) == 0) { | |
1041 | die(1, "failed to find password entry for user %d: " | |
1042 | "request group explicitly", u); | |
1043 | } | |
1044 | g = pw->pw_gid; | |
1045 | } | |
1046 | ||
1047 | /* Initialize system-specific machinery. */ | |
b093b41d | 1048 | init_sys(); |
74716d82 MW |
1049 | |
1050 | /* Load the global policy rules. */ | |
1051 | fwatch_init(&polfw, policyfile); | |
1052 | if (load_policy_file(policyfile, &policy)) | |
9da480be | 1053 | exit(1); |
9da480be | 1054 | |
74716d82 | 1055 | /* Open the random data source. */ |
9da480be MW |
1056 | if ((randfd = open("/dev/urandom", O_RDONLY)) < 0) { |
1057 | die(1, "failed to open `/dev/urandom' for reading: %s", | |
1058 | strerror(errno)); | |
1059 | } | |
1060 | ||
74716d82 | 1061 | /* Set up the I/O event system. */ |
9da480be | 1062 | sel_init(&sel); |
74716d82 MW |
1063 | |
1064 | /* Watch for some interesting signals. */ | |
1065 | sig_init(&sel); | |
1066 | sig_add(&sigint, SIGINT, quit, "SIGINT"); | |
1067 | sig_add(&sigterm, SIGTERM, quit, "SIGTERM"); | |
1068 | ||
1069 | /* Listen for incoming connections. */ | |
bf4d9761 MW |
1070 | for (ao = addroptab; ao->name; ao++) |
1071 | if (!make_listening_socket(ao, port)) any = 1; | |
74716d82 MW |
1072 | if (!any) die(1, "no IP protocols supported"); |
1073 | ||
1074 | /* Open the pidfile now, in case it's somewhere we can't write. */ | |
1075 | if (pidfile && (fp = fopen(pidfile, "w")) == 0) { | |
1076 | die(1, "failed to open pidfile `%s' for writing: %s", | |
1077 | pidfile, strerror(errno)); | |
1078 | } | |
1079 | ||
1080 | /* If we're meant to use syslog, then open the log. */ | |
1081 | if (flags & F_SYSLOG) | |
1082 | openlog(QUIS, 0, LOG_DAEMON); | |
1083 | ||
1084 | /* Drop privileges. */ | |
1085 | if ((g != -1 && (setegid(g) || setgid(g) || | |
1086 | (getuid() == 0 && setgroups(1, &g)))) || | |
1087 | (u != -1 && setuid(u))) | |
1088 | die(1, "failed to drop privileges: %s", strerror(errno)); | |
9da480be | 1089 | |
74716d82 MW |
1090 | /* Become a background process, if requested. */ |
1091 | if ((f & f_daemon) && daemonize()) | |
1092 | die(1, "failed to become daemon: %s", strerror(errno)); | |
1093 | ||
1094 | /* Write the process id to the pidfile. */ | |
1095 | if (fp) { | |
1096 | fprintf(fp, "%d\n", getpid()); | |
1097 | fclose(fp); | |
1098 | } | |
1099 | ||
1100 | /* And now we're going. */ | |
1101 | flags |= F_RUNNING; | |
1102 | ||
1103 | /* Read events and process them. */ | |
1104 | for (;;) { | |
1105 | if (sel_select(&sel) && errno != EINTR) | |
1106 | die(1, "select failed: %s", strerror(errno)); | |
1107 | } | |
9da480be | 1108 | |
74716d82 | 1109 | /* This just keeps the compiler happy. */ |
9da480be MW |
1110 | return (0); |
1111 | } | |
1112 | ||
1113 | /*----- That's all, folks -------------------------------------------------*/ |