Avoid using any of the ndis_packet/ndis_packet_private fields for

mbuf<->packet housekeeping. Instead, add a couple of extra fields
to the end of ndis_packet. These should be invisible to the Windows
driver module.

This also lets me get rid of a little bit of evil from ndis_ptom()
(frobbing of the ext_buf field instead of relying on the MEXTADD()
macro).

3 files changed, 24 insertions, 23 deletions

diff --git a/sys/compat/ndis/kern_ndis.c b/sys/compat/ndis/kern_ndis.c
index 6606b45..3186d8b 100644
--- a/sys/compat/ndis/kern_ndis.c
+++ b/sys/compat/ndis/kern_ndis.c
@@ -328,8 +328,8 @@ ndis_flush_sysctls(arg)
 }
 
 void
-ndis_return_packet(packet, arg)
-	void			*packet;
+ndis_return_packet(buf, arg)
+	void			*buf;	/* not used */
 	void			*arg;
 {
 	struct ndis_softc	*sc;
@@ -337,25 +337,25 @@ ndis_return_packet(packet, arg)
 	ndis_packet		*p;
 	__stdcall ndis_return_handler	returnfunc;
 
-	if (arg == NULL || packet == NULL)
+	if (arg == NULL)
 		return;
 
-	p = packet;
+	p = arg;
 
 	/* Decrement refcount. */
-	p->np_private.npp_count--;
+	p->np_refcnt--;
 
 	/* Release packet when refcount hits zero, otherwise return. */
-	if (p->np_private.npp_count)
+	if (p->np_refcnt)
 		return;
 
-	sc = arg;
+	sc = p->np_softc;
 	returnfunc = sc->ndis_chars.nmc_return_packet_func;
 	adapter = sc->ndis_block.nmb_miniportadapterctx;
 	if (returnfunc == NULL)
-		ndis_free_packet((ndis_packet *)packet);
+		ndis_free_packet(p);
 	else
-		returnfunc(adapter, (ndis_packet *)packet);
+		returnfunc(adapter, p);
 	return;
 }
 
@@ -474,7 +474,7 @@ ndis_ptom(m0, p)
 
 	priv = &p->np_private;
 	buf = priv->npp_head;
-	priv->npp_count = 0;
+	p->np_refcnt = 0;
 
 	for (buf = priv->npp_head; buf != NULL; buf = buf->nb_next) {
 		if (buf == priv->npp_head)
@@ -489,9 +489,8 @@ ndis_ptom(m0, p)
 		m->m_len = buf->nb_bytecount;
 		m->m_data = MDL_VA(buf);
 		MEXTADD(m, m->m_data, m->m_len, ndis_return_packet,
-		    p->np_rsvd[0], 0, EXT_NDIS);
-		m->m_ext.ext_buf = (void *)p; /* XXX */
-		priv->npp_count++;
+		    p, 0, EXT_NDIS);
+		p->np_refcnt++;
 		totlen += m->m_len;
 		if (m->m_flags & MT_HEADER)
 			*m0 = m;
diff --git a/sys/compat/ndis/ndis_var.h b/sys/compat/ndis/ndis_var.h
index 7296065..353069a 100644
--- a/sys/compat/ndis/ndis_var.h
+++ b/sys/compat/ndis/ndis_var.h
@@ -829,7 +829,6 @@ struct ndis_packet {
 		} np_macrsvd;
 	} u;
 	uint32_t		*np_rsvd[2];
-	uint8_t			np_proto_rsvd[1];
 
 	/*
 	 * This next part is probably wrong, but we need some place
@@ -838,6 +837,13 @@ struct ndis_packet {
 	ndis_packet_oob		np_oob;
 	ndis_packet_extension	np_ext;
 	ndis_sc_list		np_sclist;
+
+	/* BSD-specific stuff which should be invisible to drivers. */
+
+	uint32_t		np_refcnt;
+	void			*np_softc;
+	void			*np_m0;
+	int			np_txidx;
 };
 
 typedef struct ndis_packet ndis_packet;
diff --git a/sys/dev/if_ndis/if_ndis.c b/sys/dev/if_ndis/if_ndis.c
index 79db5e9..e199567 100644
--- a/sys/dev/if_ndis/if_ndis.c
+++ b/sys/dev/if_ndis/if_ndis.c
@@ -651,7 +651,7 @@ ndis_rxeof(adapter, packets, pktcnt)
 	for (i = 0; i < pktcnt; i++) {
 		p = packets[i];
 		/* Stash the softc here so ptom can use it. */
-		p->np_rsvd[0] = (uint32_t *)sc;
+		p->np_softc = sc;
 		if (ndis_ptom(&m0, p)) {
 			printf ("ndis%d: ptom failed\n", sc->ndis_unit);
 			ndis_return_packet(sc, p);
@@ -686,13 +686,10 @@ ndis_txeof(adapter, packet, status)
 	sc = (struct ndis_softc *)block->nmb_ifp;
 	ifp = block->nmb_ifp;
 
-	if (packet->np_rsvd[1] == NULL)
-		panic("NDIS driver corrupted reserved packet fields");
-
 	NDIS_LOCK(sc);
 
-	m = (struct mbuf *)packet->np_rsvd[1];
-	idx = (int)packet->np_rsvd[0];
+	m = packet->np_m0;
+	idx = packet->np_txidx;
 	ifp->if_opackets++;
 	if (sc->ndis_sc)
 		bus_dmamap_unload(sc->ndis_ttag, sc->ndis_tmaps[idx]);
@@ -900,9 +897,8 @@ ndis_start(ifp)
 		 * so we can free it later.
 		 */
 
-		(sc->ndis_txarray[sc->ndis_txidx])->np_rsvd[0] =
-		    (uint32_t *)sc->ndis_txidx;
-		(sc->ndis_txarray[sc->ndis_txidx])->np_rsvd[1] = (uint32_t *)m;
+		(sc->ndis_txarray[sc->ndis_txidx])->np_txidx = sc->ndis_txidx;
+		(sc->ndis_txarray[sc->ndis_txidx])->np_m0 = m;
 
 		/*
 		 * Do scatter/gather processing, if driver requested it.