1 /*
2 * Copyright (c) 1986, 1988 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #ifndef lint
35 static char sccsid[] = "@(#)ns_maint.c 4.39 (Berkeley) 3/2/91";
36 #endif /* not lint */
37
38 #include <sys/param.h>
39 #include <sys/socket.h>
40 #include <sys/time.h>
41 #if defined(SYSV)
42 #include <unistd.h>
43 #endif SYSV
44 #include <netinet/in.h>
45 #include <stdio.h>
46 #include <syslog.h>
47 #include <signal.h>
48 #include <errno.h>
49 #include <arpa/nameser.h>
50 #include <sys/wait.h>
51 #include "ns.h"
52 #include "db.h"
53 #include "pathnames.h"
54
55 extern int errno;
56 extern int maint_interval;
57 extern int needzoneload;
58 extern u_short ns_port;
59 extern char *ctime();
60
61 int xfers_running; /* number of xfers running */
62 int xfers_deferred; /* number of needed xfers not run yet */
63 static int alarm_pending;
64
65
66 /*
67 * Invoked at regular intervals by signal interrupt; refresh all secondary
68 * zones from primary name server and remove old cache entries. Also,
69 * ifdef'd ALLOW_UPDATES, dump database if it has changed since last
70 * dump/bootup.
71 */
ns_maint()72 ns_maint()
73 {
74 register struct zoneinfo *zp;
75 struct itimerval ival;
76 time_t next_refresh = 0;
77 int zonenum;
78
79 gettime(&tt);
80
81 #ifdef DEBUG
82 if (debug)
83 fprintf(ddt,"\nns_maint(); now %s", ctime(&tt.tv_sec));
84 #endif
85
86 xfers_deferred = 0;
87 alarm_pending = 0;
88 for (zp = zones, zonenum = 0; zp < &zones[nzones]; zp++, zonenum++) {
89 #ifdef DEBUG
90 if (debug >= 2)
91 printzoneinfo(zonenum);
92 #endif
93 if (tt.tv_sec >= zp->z_time && zp->z_refresh > 0) {
94 /*
95 * Set default time for next action first,
96 * so that it can be changed later if necessary.
97 */
98 zp->z_time = tt.tv_sec + zp->z_refresh;
99
100 switch (zp->z_type) {
101
102 case Z_CACHE:
103 doachkpt();
104 break;
105
106 case Z_SECONDARY:
107 if ((zp->z_state & Z_NEED_RELOAD) == 0) {
108 if (zp->z_state & Z_XFER_RUNNING)
109 abortxfer(zp);
110 else if (xfers_running < MAX_XFERS_RUNNING)
111 startxfer(zp);
112 else {
113 zp->z_state |= Z_NEED_XFER;
114 ++xfers_deferred;
115 #ifdef DEBUG
116 if (debug > 1)
117 fprintf(ddt,
118 "xfer deferred for %s\n",
119 zp->z_origin);
120 #endif
121 }
122 }
123 break;
124 #ifdef ALLOW_UPDATES
125 case Z_PRIMARY:
126 /*
127 * Checkpoint the zone if it has changed
128 * since we last checkpointed
129 */
130 if (zp->hasChanged)
131 zonedump(zp);
132 break;
133 #endif ALLOW_UPDATES
134 }
135 gettime(&tt);
136 }
137 }
138 sched_maint();
139 #ifdef DEBUG
140 if (debug)
141 fprintf(ddt,"exit ns_maint()\n");
142 #endif
143 }
144
145 /*
146 * Find when the next refresh needs to be and set
147 * interrupt time accordingly.
148 */
sched_maint()149 sched_maint()
150 {
151 register struct zoneinfo *zp;
152 struct itimerval ival;
153 time_t next_refresh = 0;
154 static time_t next_alarm;
155
156 for (zp = zones; zp < &zones[nzones]; zp++)
157 if (zp->z_time != 0 &&
158 (next_refresh == 0 || next_refresh > zp->z_time))
159 next_refresh = zp->z_time;
160 /*
161 * Schedule the next call to ns_maint.
162 * Don't visit any sooner than maint_interval.
163 */
164 bzero((char *)&ival, sizeof (ival));
165 if (next_refresh != 0) {
166 if (next_refresh == next_alarm && alarm_pending) {
167 #ifdef DEBUG
168 if (debug)
169 fprintf(ddt,"sched_maint: no schedule change\n");
170 #endif
171 return;
172 }
173 ival.it_value.tv_sec = next_refresh - tt.tv_sec;
174 if (ival.it_value.tv_sec < maint_interval)
175 ival.it_value.tv_sec = maint_interval;
176 next_alarm = next_refresh;
177 alarm_pending = 1;
178 }
179 (void) setitimer(ITIMER_REAL, &ival, (struct itimerval *)NULL);
180 #ifdef DEBUG
181 if (debug)
182 fprintf(ddt,"sched_maint: Next interrupt in %d sec\n",
183 ival.it_value.tv_sec);
184 #endif
185 }
186
187 /*
188 * Start an asynchronous zone transfer for a zone.
189 * Depends on current time being in tt.
190 * The caller must call sched_maint after startxfer.
191 */
192 startxfer(zp)
193 struct zoneinfo *zp;
194 {
195 static char *argv[NSMAX + 20], argv_ns[NSMAX][MAXDNAME];
196 int cnt, argc = 0, argc_ns = 0, pid, omask;
197 char debug_str[10];
198 char serial_str[10];
199 char port_str[10];
200
201 #ifdef DEBUG
202 if (debug)
203 fprintf(ddt,"startxfer() %s\n", zp->z_origin);
204 #endif
205
206 argv[argc++] = "named-xfer";
207 argv[argc++] = "-z";
208 argv[argc++] = zp->z_origin;
209 argv[argc++] = "-f";
210 argv[argc++] = zp->z_source;
211 argv[argc++] = "-s";
212 sprintf(serial_str, "%d", zp->z_serial);
213 argv[argc++] = serial_str;
214 if (zp->z_state & Z_SYSLOGGED)
215 argv[argc++] = "-q";
216 argv[argc++] = "-P";
217 sprintf(port_str, "%d", ns_port);
218 argv[argc++] = port_str;
219 #ifdef DEBUG
220 if (debug) {
221 argv[argc++] = "-d";
222 sprintf(debug_str, "%d", debug);
223 argv[argc++] = debug_str;
224 argv[argc++] = "-l";
225 argv[argc++] = "/usr/tmp/xfer.ddt";
226 if (debug > 5) {
227 argv[argc++] = "-t";
228 argv[argc++] = "/usr/tmp/xfer.trace";
229 }
230 }
231 #endif
232
233 /*
234 * Copy the server ip addresses into argv, after converting
235 * to ascii and saving the static inet_ntoa result
236 */
237 for (cnt = 0; cnt < zp->z_addrcnt; cnt++)
238 argv[argc++] = strcpy(argv_ns[argc_ns++],
239 inet_ntoa(zp->z_addr[cnt]));
240
241 argv[argc] = 0;
242
243 #ifdef DEBUG
244 #ifdef ECHOARGS
245 if (debug) {
246 int i;
247 for (i = 0; i < argc; i++)
248 fprintf(ddt, "Arg %d=%s\n", i, argv[i]);
249 }
250 #endif /* ECHOARGS */
251 #endif /* DEBUG */
252
253 #ifdef SYSV
254 #define vfork fork
255 #else
256 gettime(&tt);
257 omask = sigblock(sigmask(SIGCHLD));
258 #endif
259 if ((pid = vfork()) == -1) {
260 #ifdef DEBUG
261 if (debug)
262 fprintf(ddt, "xfer [v]fork: %d\n", errno);
263 #endif
264 syslog(LOG_ERR, "xfer [v]fork: %m");
265 #ifndef SYSV
266 (void) sigsetmask(omask);
267 #endif
268 zp->z_time = tt.tv_sec + 10;
269 return;
270 }
271
272 if (pid) {
273 #ifdef DEBUG
274 if (debug)
275 fprintf(ddt, "started xfer child %d\n", pid);
276 #endif
277 zp->z_state &= ~Z_NEED_XFER;
278 zp->z_state |= Z_XFER_RUNNING;
279 zp->z_xferpid = pid;
280 xfers_running++;
281 zp->z_time = tt.tv_sec + MAX_XFER_TIME;
282 #ifndef SYSV
283 (void) sigsetmask(omask);
284 #endif
285 } else {
286 execve(_PATH_XFER, argv, NULL);
287 syslog(LOG_ERR, "can't exec %s: %m", _PATH_XFER);
288 _exit(XFER_FAIL); /* avoid duplicate buffer flushes */
289 }
290 }
291
292 #ifdef DEBUG
printzoneinfo(zonenum)293 printzoneinfo(zonenum)
294 int zonenum;
295 {
296 struct timeval tt;
297 struct zoneinfo *zp = &zones[zonenum];
298 char *ZoneType;
299
300 if (!debug)
301 return; /* Else fprintf to ddt will bomb */
302 fprintf(ddt, "printzoneinfo(%d):\n", zonenum);
303
304 gettime(&tt);
305 switch (zp->z_type) {
306 case Z_PRIMARY: ZoneType = "Primary"; break;
307 case Z_SECONDARY: ZoneType = "Secondary"; break;
308 case Z_CACHE: ZoneType = "Cache"; break;
309 default: ZoneType = "Unknown";
310 }
311 if (zp->z_origin[0] == '\0')
312 fprintf(ddt,"origin ='.'");
313 else
314 fprintf(ddt,"origin ='%s'", zp->z_origin);
315 fprintf(ddt,", type = %s", ZoneType);
316 fprintf(ddt,", source = %s\n", zp->z_source);
317 fprintf(ddt,"z_refresh = %ld", zp->z_refresh);
318 fprintf(ddt,", retry = %ld", zp->z_retry);
319 fprintf(ddt,", expire = %ld", zp->z_expire);
320 fprintf(ddt,", minimum = %ld", zp->z_minimum);
321 fprintf(ddt,", serial = %ld\n", zp->z_serial);
322 fprintf(ddt,"z_time = %d", zp->z_time);
323 if (zp->z_time) {
324 fprintf(ddt,", now time : %d sec", tt.tv_sec);
325 fprintf(ddt,", time left: %d sec", zp->z_time - tt.tv_sec);
326 }
327 fprintf(ddt,"; state %x\n", zp->z_state);
328 }
329 #endif DEBUG
330
331 /*
332 * remove_zone (htp, zone) --
333 * Delete all RR's in the zone "zone" under specified hash table.
334 */
remove_zone(htp,zone)335 remove_zone(htp, zone)
336 register struct hashbuf *htp;
337 register int zone;
338 {
339 register struct databuf *dp, *pdp;
340 register struct namebuf *np;
341 struct namebuf **npp, **nppend;
342
343 nppend = htp->h_tab + htp->h_size;
344 for (npp = htp->h_tab; npp < nppend; npp++)
345 for (np = *npp; np != NULL; np = np->n_next) {
346 for (pdp = NULL, dp = np->n_data; dp != NULL; ) {
347 if (dp->d_zone == zone)
348 dp = rm_datum(dp, np, pdp);
349 else {
350 pdp = dp;
351 dp = dp->d_next;
352 }
353 }
354 /* Call recursively to remove subdomains. */
355 if (np->n_hash)
356 remove_zone(np->n_hash, zone);
357 }
358 }
359
360 /*
361 * Abort an xfer that has taken too long.
362 */
abortxfer(zp)363 abortxfer(zp)
364 register struct zoneinfo *zp;
365 {
366
367 kill(zp->z_xferpid, SIGKILL); /* don't trust it at all */
368 #ifdef DEBUG
369 if (debug)
370 fprintf(ddt, "Killed child %d (zone %s) due to timeout\n",
371 zp->z_xferpid, zp->z_origin);
372 #endif /* DEBUG */
373 zp->z_time = tt.tv_sec + zp->z_retry;
374 }
375
376 #ifdef SYSV
377 union wait {
378 unsigned short w_termsig:7; /* termination signal */
379 unsigned short w_coredump:1; /* core dump indicator */
380 unsigned short w_retcode:8; /* exit code if w_termsig==0 */
381 };
382 #endif
383
384 /*
385 * SIGCHLD signal handler: process exit of xfer's.
386 * (Note: also called when outgoing transfer completes.)
387 */
388 SIG_FN
endxfer()389 endxfer()
390 {
391 register struct zoneinfo *zp;
392 int pid, xfers = 0;
393 union wait status;
394
395 gettime(&tt);
396 #if defined(SYSV)
397 { int stat;
398 pid = wait(&stat);
399 status.w_termsig = stat & 0x7f;
400 status.w_retcode = stat >> 8;
401 }
402 #else /* SYSV */
403 while ((pid =
404 wait3((int *)&status, WNOHANG, (struct rusage *)NULL)) > 0) {
405 #endif /* SYSV */
406 for (zp = zones; zp < &zones[nzones]; zp++)
407 if (zp->z_xferpid == pid) {
408 xfers++;
409 xfers_running--;
410 zp->z_xferpid = 0;
411 zp->z_state &= ~Z_XFER_RUNNING;
412 #ifdef DEBUG
413 if (debug)
414 fprintf(ddt,
415 "\nendxfer: child %d zone %s returned status=%d termsig=%d\n",
416 pid, zp->z_origin, status.w_retcode,
417 status.w_termsig);
418 #endif
419 if (status.w_termsig != 0) {
420 if (status.w_termsig != SIGKILL) {
421 syslog(LOG_ERR,
422 "named-xfer exited with signal %d\n",
423 status.w_termsig);
424 #ifdef DEBUG
425 if (debug)
426 fprintf(ddt,
427 "\tchild termination with signal %d\n",
428 status.w_termsig);
429 #endif
430 }
431 zp->z_time = tt.tv_sec + zp->z_retry;
432 } else switch (status.w_retcode) {
433 case XFER_UPTODATE:
434 zp->z_state &= ~Z_SYSLOGGED;
435 zp->z_lastupdate = tt.tv_sec;
436 zp->z_time = tt.tv_sec + zp->z_refresh;
437 /*
438 * Restore z_auth in case expired,
439 * but only if there were no errors
440 * in the zone file.
441 */
442 if ((zp->z_state & Z_DB_BAD) == 0)
443 zp->z_auth = 1;
444 if (zp->z_source) {
445 #if defined(SYSV)
446 struct utimbuf t;
447
448 t.actime = tt.tv_sec;
449 t.modtime = tt.tv_sec;
450 (void) utime(zp->z_source, &t);
451 #else
452 struct timeval t[2];
453
454 t[0] = tt;
455 t[1] = tt;
456 (void) utimes(zp->z_source, t);
457 #endif /* SYSV */
458 }
459 break;
460
461 case XFER_SUCCESS:
462 zp->z_state |= Z_NEED_RELOAD;
463 zp->z_state &= ~Z_SYSLOGGED;
464 needzoneload++;
465 break;
466
467 case XFER_TIMEOUT:
468 #ifdef DEBUG
469 if (debug) fprintf(ddt,
470 "zoneref: Masters for secondary zone %s unreachable\n",
471 zp->z_origin);
472 #endif
473 if ((zp->z_state & Z_SYSLOGGED) == 0) {
474 zp->z_state |= Z_SYSLOGGED;
475 syslog(LOG_WARNING,
476 "zoneref: Masters for secondary zone %s unreachable",
477 zp->z_origin);
478 }
479 zp->z_time = tt.tv_sec + zp->z_retry;
480 break;
481
482 default:
483 if ((zp->z_state & Z_SYSLOGGED) == 0) {
484 zp->z_state |= Z_SYSLOGGED;
485 syslog(LOG_ERR,
486 "named-xfer exit code %d",
487 status.w_retcode);
488 }
489 /* FALLTHROUGH */
490 case XFER_FAIL:
491 zp->z_state |= Z_SYSLOGGED;
492 zp->z_time = tt.tv_sec + zp->z_retry;
493 break;
494 }
495 break;
496 }
497 #ifndef SYSV
498 }
499 #endif /* SYSV */
500 if (xfers) {
501 for (zp = zones;
502 xfers_deferred != 0 && xfers_running < MAX_XFERS_RUNNING &&
503 zp < &zones[nzones]; zp++)
504 if (zp->z_state & Z_NEED_XFER) {
505 xfers_deferred--;
506 startxfer(zp);
507 }
508 sched_maint();
509 }
510 #if defined(SYSV)
511 (void)signal(SIGCLD, endxfer);
512 #endif
513 }
514
515 /*
516 * Reload zones whose transfers have completed.
517 */
loadxfer()518 loadxfer()
519 {
520 register struct zoneinfo *zp;
521
522 gettime(&tt);
523 for (zp = zones; zp < &zones[nzones]; zp++)
524 if (zp->z_state & Z_NEED_RELOAD) {
525 #ifdef DEBUG
526 if (debug)
527 fprintf(ddt, "loadxfer() '%s'\n",
528 zp->z_origin[0] ? zp->z_origin : ".");
529 #endif
530 zp->z_state &= ~Z_NEED_RELOAD;
531 zp->z_auth = 0;
532 remove_zone(hashtab, zp - zones);
533 if (db_load(zp->z_source, zp->z_origin, zp, 0) == 0)
534 zp->z_auth = 1;
535 if (zp->z_state & Z_TMP_FILE)
536 (void) unlink(zp->z_source);
537 }
538 sched_maint();
539 }
540