4.3BSD-Reno/src/usr.sbin/named/ns_maint.c
/*
* Copyright (c) 1986, 1988 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted provided
* that: (1) source distributions retain this entire copyright notice and
* comment, and (2) distributions including binaries display the following
* acknowledgement: ``This product includes software developed by the
* University of California, Berkeley and its contributors'' in the
* documentation or other materials provided with the distribution and in
* all advertising materials mentioning features or use of this software.
* Neither the name of the University nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
static char sccsid[] = "@(#)ns_maint.c 4.37 (Berkeley) 6/1/90";
#endif /* not lint */
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#if defined(SYSV)
#include <unistd.h>
#endif SYSV
#include <netinet/in.h>
#include <stdio.h>
#include <syslog.h>
#include <signal.h>
#include <errno.h>
#include <arpa/nameser.h>
#include <sys/wait.h>
#include "ns.h"
#include "db.h"
#include "pathnames.h"
extern int errno;
extern int maint_interval;
extern int needzoneload;
extern u_short ns_port;
extern char *ctime();
int xfers_running; /* number of xfers running */
int xfers_deferred; /* number of needed xfers not run yet */
static int alarm_pending;
/*
* Invoked at regular intervals by signal interrupt; refresh all secondary
* zones from primary name server and remove old cache entries. Also,
* ifdef'd ALLOW_UPDATES, dump database if it has changed since last
* dump/bootup.
*/
ns_maint()
{
register struct zoneinfo *zp;
struct itimerval ival;
time_t next_refresh = 0;
int zonenum;
gettime(&tt);
#ifdef DEBUG
if (debug)
fprintf(ddt,"\nns_maint(); now %s", ctime(&tt.tv_sec));
#endif
xfers_deferred = 0;
alarm_pending = 0;
for (zp = zones, zonenum = 0; zp < &zones[nzones]; zp++, zonenum++) {
#ifdef DEBUG
if (debug >= 2)
printzoneinfo(zonenum);
#endif
if (tt.tv_sec >= zp->z_time && zp->z_refresh > 0) {
/*
* Set default time for next action first,
* so that it can be changed later if necessary.
*/
zp->z_time = tt.tv_sec + zp->z_refresh;
switch (zp->z_type) {
case Z_CACHE:
doachkpt();
break;
case Z_SECONDARY:
if ((zp->z_state & Z_NEED_RELOAD) == 0) {
if (zp->z_state & Z_XFER_RUNNING)
abortxfer(zp);
else if (xfers_running < MAX_XFERS_RUNNING)
startxfer(zp);
else {
zp->z_state |= Z_NEED_XFER;
++xfers_deferred;
#ifdef DEBUG
if (debug > 1)
fprintf(ddt,
"xfer deferred for %s\n",
zp->z_origin);
#endif
}
}
break;
#ifdef ALLOW_UPDATES
case Z_PRIMARY:
/*
* Checkpoint the zone if it has changed
* since we last checkpointed
*/
if (zp->hasChanged)
zonedump(zp);
break;
#endif ALLOW_UPDATES
}
gettime(&tt);
}
}
sched_maint();
#ifdef DEBUG
if (debug)
fprintf(ddt,"exit ns_maint()\n");
#endif
}
/*
* Find when the next refresh needs to be and set
* interrupt time accordingly.
*/
sched_maint()
{
register struct zoneinfo *zp;
struct itimerval ival;
time_t next_refresh = 0;
static time_t next_alarm;
for (zp = zones; zp < &zones[nzones]; zp++)
if (zp->z_time != 0 &&
(next_refresh == 0 || next_refresh > zp->z_time))
next_refresh = zp->z_time;
/*
* Schedule the next call to ns_maint.
* Don't visit any sooner than maint_interval.
*/
bzero((char *)&ival, sizeof (ival));
if (next_refresh != 0) {
if (next_refresh == next_alarm && alarm_pending) {
#ifdef DEBUG
if (debug)
fprintf(ddt,"sched_maint: no schedule change\n");
#endif
return;
}
ival.it_value.tv_sec = next_refresh - tt.tv_sec;
if (ival.it_value.tv_sec < maint_interval)
ival.it_value.tv_sec = maint_interval;
next_alarm = next_refresh;
alarm_pending = 1;
}
(void) setitimer(ITIMER_REAL, &ival, (struct itimerval *)NULL);
#ifdef DEBUG
if (debug)
fprintf(ddt,"sched_maint: Next interrupt in %d sec\n",
ival.it_value.tv_sec);
#endif
}
/*
* Start an asynchronous zone transfer for a zone.
* Depends on current time being in tt.
* The caller must call sched_maint after startxfer.
*/
startxfer(zp)
struct zoneinfo *zp;
{
static char *argv[NSMAX + 20], argv_ns[NSMAX][MAXDNAME];
int cnt, argc = 0, argc_ns = 0, pid, omask;
char debug_str[10];
char serial_str[10];
char port_str[10];
#ifdef DEBUG
if (debug)
fprintf(ddt,"startxfer() %s\n", zp->z_origin);
#endif
argv[argc++] = "named-xfer";
argv[argc++] = "-z";
argv[argc++] = zp->z_origin;
argv[argc++] = "-f";
argv[argc++] = zp->z_source;
argv[argc++] = "-s";
sprintf(serial_str, "%d", zp->z_serial);
argv[argc++] = serial_str;
if (zp->z_state & Z_SYSLOGGED)
argv[argc++] = "-q";
argv[argc++] = "-P";
sprintf(port_str, "%d", ns_port);
argv[argc++] = port_str;
#ifdef DEBUG
if (debug) {
argv[argc++] = "-d";
sprintf(debug_str, "%d", debug);
argv[argc++] = debug_str;
argv[argc++] = "-l";
argv[argc++] = "/usr/tmp/xfer.ddt";
if (debug > 5) {
argv[argc++] = "-t";
argv[argc++] = "/usr/tmp/xfer.trace";
}
}
#endif
/*
* Copy the server ip addresses into argv, after converting
* to ascii and saving the static inet_ntoa result
*/
for (cnt = 0; cnt < zp->z_addrcnt; cnt++)
argv[argc++] = strcpy(argv_ns[argc_ns++],
inet_ntoa(zp->z_addr[cnt]));
argv[argc] = 0;
#ifdef DEBUG
#ifdef ECHOARGS
if (debug) {
int i;
for (i = 0; i < argc; i++)
fprintf(ddt, "Arg %d=%s\n", i, argv[i]);
}
#endif /* ECHOARGS */
#endif /* DEBUG */
#ifdef SYSV
#define vfork fork
#else
gettime(&tt);
omask = sigblock(sigmask(SIGCHLD));
#endif
if ((pid = vfork()) == -1) {
#ifdef DEBUG
if (debug)
fprintf(ddt, "xfer [v]fork: %d\n", errno);
#endif
syslog(LOG_ERR, "xfer [v]fork: %m");
#ifndef SYSV
(void) sigsetmask(omask);
#endif
zp->z_time = tt.tv_sec + 10;
return;
}
if (pid) {
#ifdef DEBUG
if (debug)
fprintf(ddt, "started xfer child %d\n", pid);
#endif
zp->z_state &= ~Z_NEED_XFER;
zp->z_state |= Z_XFER_RUNNING;
zp->z_xferpid = pid;
xfers_running++;
zp->z_time = tt.tv_sec + MAX_XFER_TIME;
#ifndef SYSV
(void) sigsetmask(omask);
#endif
} else {
execve(_PATH_XFER, argv, NULL);
syslog(LOG_ERR, "can't exec %s: %m", _PATH_XFER);
_exit(XFER_FAIL); /* avoid duplicate buffer flushes */
}
}
#ifdef DEBUG
printzoneinfo(zonenum)
int zonenum;
{
struct timeval tt;
struct zoneinfo *zp = &zones[zonenum];
char *ZoneType;
if (!debug)
return; /* Else fprintf to ddt will bomb */
fprintf(ddt, "printzoneinfo(%d):\n", zonenum);
gettime(&tt);
switch (zp->z_type) {
case Z_PRIMARY: ZoneType = "Primary"; break;
case Z_SECONDARY: ZoneType = "Secondary"; break;
case Z_CACHE: ZoneType = "Cache"; break;
default: ZoneType = "Unknown";
}
if (zp->z_origin[0] == '\0')
fprintf(ddt,"origin ='.'");
else
fprintf(ddt,"origin ='%s'", zp->z_origin);
fprintf(ddt,", type = %s", ZoneType);
fprintf(ddt,", source = %s\n", zp->z_source);
fprintf(ddt,"z_refresh = %ld", zp->z_refresh);
fprintf(ddt,", retry = %ld", zp->z_retry);
fprintf(ddt,", expire = %ld", zp->z_expire);
fprintf(ddt,", minimum = %ld", zp->z_minimum);
fprintf(ddt,", serial = %ld\n", zp->z_serial);
fprintf(ddt,"z_time = %d", zp->z_time);
if (zp->z_time) {
fprintf(ddt,", now time : %d sec", tt.tv_sec);
fprintf(ddt,", time left: %d sec", zp->z_time - tt.tv_sec);
}
fprintf(ddt,"; state %x\n", zp->z_state);
}
#endif DEBUG
/*
* remove_zone (htp, zone) --
* Delete all RR's in the zone "zone" under specified hash table.
*/
remove_zone(htp, zone)
register struct hashbuf *htp;
register int zone;
{
register struct databuf *dp, *pdp;
register struct namebuf *np;
struct namebuf **npp, **nppend;
nppend = htp->h_tab + htp->h_size;
for (npp = htp->h_tab; npp < nppend; npp++)
for (np = *npp; np != NULL; np = np->n_next) {
for (pdp = NULL, dp = np->n_data; dp != NULL; ) {
if (dp->d_zone == zone)
dp = rm_datum(dp, np, pdp);
else {
pdp = dp;
dp = dp->d_next;
}
}
/* Call recursively to remove subdomains. */
if (np->n_hash)
remove_zone(np->n_hash, zone);
}
}
/*
* Abort an xfer that has taken too long.
*/
abortxfer(zp)
register struct zoneinfo *zp;
{
kill(zp->z_xferpid, SIGKILL); /* don't trust it at all */
#ifdef DEBUG
if (debug)
fprintf(ddt, "Killed child %d (zone %s) due to timeout\n",
zp->z_xferpid, zp->z_origin);
#endif /* DEBUG */
zp->z_time = tt.tv_sec + zp->z_retry;
}
#ifdef SYSV
union wait {
unsigned short w_termsig:7; /* termination signal */
unsigned short w_coredump:1; /* core dump indicator */
unsigned short w_retcode:8; /* exit code if w_termsig==0 */
};
#endif
/*
* SIGCHLD signal handler: process exit of xfer's.
* (Note: also called when outgoing transfer completes.)
*/
VOID
endxfer()
{
register struct zoneinfo *zp;
int pid, xfers = 0;
union wait status;
gettime(&tt);
#if defined(SYSV)
{ int stat;
pid = wait(&stat);
status.w_termsig = stat & 0x7f;
status.w_retcode = stat >> 8;
}
#else /* SYSV */
while ((pid = wait3(&status, WNOHANG, (struct rusage *)NULL)) > 0) {
#endif /* SYSV */
for (zp = zones; zp < &zones[nzones]; zp++)
if (zp->z_xferpid == pid) {
xfers++;
xfers_running--;
zp->z_xferpid = 0;
zp->z_state &= ~Z_XFER_RUNNING;
#ifdef DEBUG
if (debug)
fprintf(ddt,
"\nendxfer: child %d zone %s returned status=%d termsig=%d\n",
pid, zp->z_origin, status.w_retcode,
status.w_termsig);
#endif
if (status.w_termsig != 0) {
if (status.w_termsig != SIGKILL) {
syslog(LOG_ERR,
"named-xfer exited with signal %d\n",
status.w_termsig);
#ifdef DEBUG
if (debug)
fprintf(ddt,
"\tchild termination with signal %d\n",
status.w_termsig);
#endif
}
zp->z_time = tt.tv_sec + zp->z_retry;
} else switch (status.w_retcode) {
case XFER_UPTODATE:
zp->z_state &= ~Z_SYSLOGGED;
zp->z_lastupdate = tt.tv_sec;
zp->z_time = tt.tv_sec + zp->z_refresh;
/*
* Restore z_auth in case expired,
* but only if there were no errors
* in the zone file.
*/
if ((zp->z_state & Z_DB_BAD) == 0)
zp->z_auth = 1;
if (zp->z_source) {
#if defined(SYSV)
struct utimbuf t;
t.actime = tt.tv_sec;
t.modtime = tt.tv_sec;
(void) utime(zp->z_source, &t);
#else
struct timeval t[2];
t[0] = tt;
t[1] = tt;
(void) utimes(zp->z_source, t);
#endif /* SYSV */
}
break;
case XFER_SUCCESS:
zp->z_state |= Z_NEED_RELOAD;
zp->z_state &= ~Z_SYSLOGGED;
needzoneload++;
break;
case XFER_TIMEOUT:
#ifdef DEBUG
if (debug) fprintf(ddt,
"zoneref: Masters for secondary zone %s unreachable\n",
zp->z_origin);
#endif
if ((zp->z_state & Z_SYSLOGGED) == 0) {
zp->z_state |= Z_SYSLOGGED;
syslog(LOG_WARNING,
"zoneref: Masters for secondary zone %s unreachable",
zp->z_origin);
}
zp->z_time = tt.tv_sec + zp->z_retry;
break;
default:
if ((zp->z_state & Z_SYSLOGGED) == 0) {
zp->z_state |= Z_SYSLOGGED;
syslog(LOG_ERR,
"named-xfer exit code %d",
status.w_retcode);
}
/* FALLTHROUGH */
case XFER_FAIL:
zp->z_state |= Z_SYSLOGGED;
zp->z_time = tt.tv_sec + zp->z_retry;
break;
}
break;
}
#ifndef SYSV
}
#endif /* SYSV */
if (xfers) {
for (zp = zones;
xfers_deferred != 0 && xfers_running < MAX_XFERS_RUNNING &&
zp < &zones[nzones]; zp++)
if (zp->z_state & Z_NEED_XFER) {
xfers_deferred--;
startxfer(zp);
}
sched_maint();
}
#if defined(SYSV)
(void)signal(SIGCLD, endxfer);
#endif
}
/*
* Reload zones whose transfers have completed.
*/
loadxfer()
{
register struct zoneinfo *zp;
gettime(&tt);
for (zp = zones; zp < &zones[nzones]; zp++)
if (zp->z_state & Z_NEED_RELOAD) {
#ifdef DEBUG
if (debug)
fprintf(ddt, "loadxfer() '%s'\n",
zp->z_origin[0] ? zp->z_origin : ".");
#endif
zp->z_state &= ~Z_NEED_RELOAD;
zp->z_auth = 0;
remove_zone(hashtab, zp - zones);
if (db_load(zp->z_source, zp->z_origin, zp, 0) == 0)
zp->z_auth = 1;
if (zp->z_state & Z_TMP_FILE)
(void) unlink(zp->z_source);
}
sched_maint();
}