When I put up an AOLserver 4 instance with host-based virtual servers, I
found that when the Nimda-infected folks came looking for
/default.ida+NNNNNN... on virtual host "www.worm.com", the AOLserver would
never close the connection because NsQueueConn would always return 0
without doing any work, so the conn couldn't be closed, but it was never
processed. After scouting for a fix, I thought the best way to fix it
would be to assign a first defined virtual server to be the "default"
virtual server, which will get those conns if no other Host header matches.
I think this is reasonable, because it allows you to do things like
logging these connections, or returning targeted responses when they are
encountered -- if the conn is just closed, then the traces aren't run, so
no logging occurs, and you can't catch the conn. I think assigning the
conn to a default server is probably better than just closing it.
I thought about providing a config directive to assign the default server,
but I decided that using the first server defined in the "ns/servers"
section is just as flexible.
If this is acceptable, I'd be willing to augment the config doc with a
description of the behavior.
I've tested this patch on my server, and it appears to work.
Here's my simple patch:
diff -ur --exclude=CVS aolserver/nsd/nsd.h aolserver-vsfix/nsd/nsd.h
--- aolserver/nsd/nsd.h Tue Oct 29 19:01:51 2002
+++ aolserver-vsfix/nsd/nsd.h Mon Jan 13 21:33:47 2003
@@ -110,6 +110,8 @@
typedef int bool;
+struct NsServer;
+
struct _nsconf {
char *argv0;
char *nsd;
@@ -131,6 +133,7 @@
*/
Tcl_HashTable servertable;
+ struct NsServer *defaultserver;
Tcl_DString servers;
/*
@@ -261,8 +264,6 @@
* The following structure maitains data for each instance of
* a driver initialized with Ns_DriverInit.
*/
-
-struct NsServer;
typedef struct Driver {
diff -ur --exclude=CVS aolserver/nsd/queue.c aolserver-vsfix/nsd/queue.c
--- aolserver/nsd/queue.c Tue Oct 29 19:02:06 2002
+++ aolserver-vsfix/nsd/queue.c Mon Jan 13 21:39:21 2003
@@ -244,10 +244,9 @@
servPtr = Tcl_GetHashValue(hPtr);
}
}
-fprintf(stderr, "%s %p\n", host, servPtr);
}
if (servPtr == NULL) {
- return 0;
+ servPtr = nsconf.defaultserver;
}
/*
diff -ur --exclude=CVS aolserver/nsd/server.c aolserver-vsfix/nsd/server.c
--- aolserver/nsd/server.c Tue Oct 29 19:02:13 2002
+++ aolserver-vsfix/nsd/server.c Mon Jan 13 21:35:39 2003
@@ -125,6 +125,9 @@
hPtr = Tcl_FirstHashEntry(&nsconf.servertable, &search);
while (hPtr != NULL) {
servPtr = Tcl_GetHashValue(hPtr);
+ if (nsconf.defaultserver == NULL) {
+ nsconf.defaultserver = servPtr;
+ }
NsStartServer(servPtr);
hPtr = Tcl_NextHashEntry(&search);
}
