Rework IPX/SPX socket and pcb reference model:

- Introduce invariant that all IPX/SPX sockets will have valid so_pcb
  pointers to ipxpcb structures, and that for SPX, the control block
  pointer will always be valid.  Don't attempt to free the socket or
  pcb at various odd points, such as disconnect.

- Add a new ipxpcb flag, IPXP_DROPPED, which will be set in place of
  freeing PCB's so that this invariant can be maintained.  This flag
  is now checked instead of a NULL check in various socket protocol
  calls.

- Introduce many assertions that this invariant holds.

- Various pieces of code, such as the SPX timer code, no longer needs
  to jump through hoops in case it frees a PCB while running.

- Break out ipx_pcbfree() from ipx_pcbdetach().  Likewise
  spx_pcbdetach().

- Comment on some SMP-related limitations to the SPX code.

- Update copyrights.

MFC after:	1 month

1 files changed, 11 insertions, 8 deletions

diff --git a/sys/netipx/ipx_pcb.h b/sys/netipx/ipx_pcb.h
index e5de871..86071c1 100644
--- a/sys/netipx/ipx_pcb.h
+++ b/sys/netipx/ipx_pcb.h
@@ -2,7 +2,7 @@
  * Copyright (c) 1984, 1985, 1986, 1987, 1993
  *	The Regents of the University of California.  All rights reserved.
  * Copyright (c) 1995, Mike Mitchell
- * Copyright (c) 2004-2005 Robert N. M. Watson
+ * Copyright (c) 2004-2006 Robert N. M. Watson
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -68,13 +68,15 @@ extern struct ipxpcbhead ipxrawpcb_list;
 extern struct mtx	ipxpcb_list_mtx;
 #endif
 
-/* possible flags */
-
-#define IPXP_IN_ABORT		0x1	/* calling abort through socket */
-#define IPXP_RAWIN		0x2	/* show headers on input */
-#define IPXP_RAWOUT		0x4	/* show header on output */
-#define IPXP_ALL_PACKETS	0x8	/* Turn off higher proto processing */
-#define	IPXP_CHECKSUM		0x10	/* use checksum on this socket */
+/*
+ * IPX/SPX PCB flags.
+ */
+#define IPXP_IN_ABORT		0x1	/* Calling abort through socket. */
+#define IPXP_RAWIN		0x2	/* Show headers on input. */
+#define IPXP_RAWOUT		0x4	/* Show header on output. */
+#define IPXP_ALL_PACKETS	0x8	/* Turn off higher proto processing. */
+#define	IPXP_CHECKSUM		0x10	/* Use checksum on this socket. */
+#define	IPXP_DROPPED		0x20	/* Connection dropped. */
 
 #define	IPX_WILDCARD		1
 
@@ -98,6 +100,7 @@ int	ipx_pcbconnect(struct ipxpcb *ipxp, struct sockaddr *nam,
 			    struct thread *p);
 void	ipx_pcbdetach(struct ipxpcb *ipxp);
 void	ipx_pcbdisconnect(struct ipxpcb *ipxp);
+void	ipx_pcbfree(struct ipxpcb *ipxp);
 struct ipxpcb *
 	ipx_pcblookup(struct ipx_addr *faddr, int lport, int wildp);
 void	ipx_setpeeraddr(struct ipxpcb *ipxp, struct sockaddr **nam);