changed the format of the wins.dat file slightly.

It now has a line like this:

VERSION 1 251152

the first number is a version #define in nmbd_winsserver.c and will be
used if we ever have to change the format again.

The second number is a hash of the current interfaces setting. It is
used to detect the case where nmbd is restarted on a machine after the
IP of the machine has changed (or the interfaces list has changed in
any way). When that happens we need to discard the old wins.dat cache
or you end up with chaos. This has bitten quite a few people, they
find that when they move a machine it continues using the old IP for
some things for the next week until the wins entries time out!

I've checked, and the old nmbd can handle the new format, although it
does spit out a spurious error message about the VERSION line. So
users can safely run 2.0alpha then switch back to 1.9.18 without
problems.
(This used to be commit c4a8cdc60a5b01894ab2456e77b6d89d4c16a088)

1 files changed, 16 insertions, 0 deletions

diff --git a/source3/nmbd/nmbd_winsserver.c b/source3/nmbd/nmbd_winsserver.c
index dfa52a65f8..11e0aaecd6 100644
--- a/source3/nmbd/nmbd_winsserver.c
+++ b/source3/nmbd/nmbd_winsserver.c
@@ -24,6 +24,7 @@
 #include "includes.h"
 
 #define WINS_LIST "wins.dat"
+#define WINS_VERSION 1
 
 extern int DEBUGLEVEL;
 extern struct in_addr ipzero;
@@ -158,6 +159,8 @@ BOOL initialise_wins(void)
     BOOL got_token;
     BOOL was_ip;
     int i;
+    unsigned hash;
+    int version;
 
     /* Read a line from the wins.dat file. Strips whitespace
        from the beginning and end of the line.
@@ -168,6 +171,17 @@ BOOL initialise_wins(void)
     if (*line == '#')
       continue;
 
+    if (strncmp(line,"VERSION ", 8) == 0) {
+	    if (sscanf(line,"VERSION %d %u", &version, &hash) != 2 ||
+		version != WINS_VERSION ||
+		hash != iface_hash()) {
+		    DEBUG(0,("Discarding invalid wins.dat file [%s]\n",line));
+		    fclose(fp);
+		    return True;
+	    }
+	    continue;
+    }
+
     ptr = line;
 
     /* 
@@ -1561,6 +1575,8 @@ void wins_write_database(void)
   }
 
   DEBUG(4,("wins_write_database: Dump of WINS name list.\n"));
+
+  fprintf(fp,"VERSION %d %u\n", WINS_VERSION, iface_hash());
  
   for( namerec 
            = (struct name_record *)ubi_trFirst( wins_server_subnet->namelist );