diff -dru djbdns-1.05/cache.c djbdns-1.05.fjo/cache.c
--- djbdns-1.05/cache.c	Sun Feb 11 22:11:45 2001
+++ djbdns-1.05.fjo/cache.c	Mon Nov 10 13:43:11 2003
@@ -1,9 +1,17 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <endian.h>
+#include <signal.h>
 #include "alloc.h"
 #include "byte.h"
 #include "uint32.h"
 #include "exit.h"
 #include "tai.h"
 #include "cache.h"
+#include "strerr.h"
 
 uint64 cache_motion = 0;
 
@@ -14,6 +22,143 @@
 static uint32 oldest;
 static uint32 unused;
 
+int do_cache_save = 0;
+int do_cache_save_impossible_now = 1;
+
+int cache_save_entry (char *cache, uint32 *len, uint32 *pos)
+{
+  char *dest = cache + *len, *source = x + *pos;
+  uint32 keylen, keylen_bigendian, datalen, datalen_bigendian;
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+  uint32_unpack(source + 4, &keylen_bigendian);
+  uint32_unpack(source + 8, &datalen_bigendian);
+  keylen = keylen_bigendian;
+  datalen = datalen_bigendian;
+#else
+  uint32_unpack_big(source + 4, &keylen_bigendian);
+  uint32_unpack_big(source + 8, &datalen_bigendian);
+  uint32_unpack(source + 4, &keylen);
+  uint32_unpack(source + 8, &datalen);
+#endif
+
+  /* stored in big endian */
+  byte_copy(dest, 4, &keylen_bigendian);                        /* keylen  */
+  byte_copy(dest + 4, 4, &datalen_bigendian);                   /* datalen */
+
+  /* tai is always stored big endian */
+  byte_copy(dest + 8, 8, source + 12);                          /* expire  */
+  byte_copy(dest + 16, keylen, source + 20);                    /* key     */
+  byte_copy(dest + 16 + keylen, datalen, source + 20 + keylen); /* data    */
+  *pos += keylen + datalen + 20;
+  *len += keylen + datalen + 16;
+  return 0;
+}
+
+#define CACHEFILE "cache/cache"
+#define CACHETMPFILE CACHEFILE ".tmp"
+int cache_save ()
+{
+  char *cache;
+  int fh;
+  uint32 len, pos;
+
+  cache = alloc(size);
+  if (!cache) return -1;
+
+  for (pos = hsize, len = 0; pos < writer; )
+    if (cache_save_entry(cache, &len, &pos) == -1) return -1;
+
+  for (pos = oldest; pos < unused; )
+    if (cache_save_entry(cache, &len, &pos) == -1) return -1;
+
+  fh = open(CACHETMPFILE, O_CREAT | O_TRUNC | O_WRONLY, 0640);
+  if (fh < 0) return -1;
+
+  if (write(fh, cache, len) != len) {
+    close(fh);
+    unlink(CACHETMPFILE);
+    return -1;
+  }
+
+  if (close(fh)) {
+    unlink(CACHETMPFILE);
+    return -1;
+  }
+
+  if (rename(CACHETMPFILE, CACHEFILE)) {
+    unlink(CACHETMPFILE);
+    return -1;
+  }
+
+  alloc_free(cache);
+  return 0;
+}
+
+int cache_load ()
+{
+  int fh;
+  struct stat st;
+  char *cache, *key, *data;
+  struct tai now, expire;
+  uint32 keylen, datalen;
+  off_t len, tmp;
+
+  fh = open(CACHEFILE, O_RDONLY);
+  if (fh < 0) return 0;
+  if (fstat(fh, &st)) return -1;
+  len = st.st_size;
+  cache = alloc(len);
+  if (!cache) return -1;
+  if (read(fh, cache, len) != len) return -1;
+  if (close(fh)) return -1;
+  tai_now(&now);
+  for (tmp = 0; tmp < len;) {
+
+    uint32_unpack_big(cache + tmp, &keylen);
+    uint32_unpack_big(cache + tmp + 4, &datalen);
+    tai_unpack(cache + tmp + 8, &expire);
+
+    if (len < tmp + 16 + keylen + datalen) break;
+
+    key = cache + tmp + 16;
+    data = key + keylen;
+    if (expire.x > now.x) {
+      tai_sub(&expire, &expire, &now);
+      cache_set(key, keylen, data, datalen, expire.x);
+    }
+    tmp += 16 + keylen + datalen;
+  }
+
+  alloc_free(cache);
+  return 0;
+}
+
+const char *fatal;
+void cache_sighandler (int i)
+{
+  if (do_cache_save_impossible_now)
+    do_cache_save = 1;
+  else {
+    if (cache_save() == -1)
+      strerr_die2x(111,fatal,"unable to save cache file");
+    do_cache_save = 0;
+    strerr_warn1("cache saved", 0);
+    strerr_die1x(0, "going down");
+  }
+}
+
+int cache_set_sighandler (const char *c)
+{
+  struct sigaction sa;
+
+  fatal = c;
+  byte_zero((char*) &sa, sizeof(struct sigaction));
+  sa.sa_handler = cache_sighandler;
+  do_cache_save_impossible_now = 0;
+  return sigaction(SIGTERM, &sa, NULL);
+}
+
 /*
 100 <= size <= 1000000000.
 4 <= hsize <= size/16.
@@ -141,6 +286,8 @@
 
   entrylen = keylen + datalen + 20;
 
+  do_cache_save_impossible_now = 1;
+
   while (writer + entrylen > oldest) {
     if (oldest == unused) {
       if (writer <= hsize) return;
@@ -179,6 +326,8 @@
   set4(keyhash,writer);
   writer += entrylen;
   cache_motion += entrylen;
+  do_cache_save_impossible_now = 0;
+  if (do_cache_save) cache_sighandler(0);
 }
 
 int cache_init(unsigned int cachesize)
diff -dru djbdns-1.05/dnscache.c djbdns-1.05.fjo/dnscache.c
--- djbdns-1.05/dnscache.c	Sun Feb 11 22:11:45 2001
+++ djbdns-1.05.fjo/dnscache.c	Mon Nov 10 13:43:11 2003
@@ -442,6 +442,12 @@
   if (socket_listen(tcp53,20) == -1)
     strerr_die2sys(111,FATAL,"unable to listen on TCP socket: ");
 
+  if (cache_load() == -1)
+    strerr_die2x(111,FATAL,"unable to load cache file");
+
+  if (cache_set_sighandler(FATAL) == -1)
+    strerr_die2x(111,FATAL,"unable to set signal handler");
+
   log_startup();
   doit();
 }