PERFORCE change 113744 for review

[Robert Watson]

http://perforce.freebsd.org/chv.cgi?CH=113744

Change 113744 by rwatson at rwatson_cinnamon on 2007/01/31 01:50:59

	Disable bpfread() for BPF devices in anything but buffered mode
	until such time as we implement proper support methods for other
	buffer modes.  I.e., a uiomove able to scatter-gather from the
	zbuf buffer layout.
	
	Move bpf_ready() from a macro inbpfdesc.h to bpf.c as a function.
	Add locking assertion to it.  We will be reformulating this to
	take into account "ready to read" differences between buffer
	modes.

Affected files ...

.. //depot/projects/zcopybpf/src/sys/net/bpf.c#5 edit
.. //depot/projects/zcopybpf/src/sys/net/bpfdesc.h#4 edit

Differences ...

==== //depot/projects/zcopybpf/src/sys/net/bpf.c#5 (text+ko) ====

@@ -641,6 +641,15 @@
 		return (EINVAL);
 
 	BPFD_LOCK(d);
+	if (d->bd_bufmode != BPF_BUFMODE_BUFFER) {
+		/*
+		 * XXXRW: For now, we don't implement a uiomove for the
+		 * scatter-gather buffers associated with BPF_BUFMODE_ZBUF,
+		 * so simply disallow read().
+		 */
+		BPFD_UNLOCK(d);
+		return (EOPNOTSUPP);
+	}
 	if (d->bd_state == BPF_WAITING)
 		callout_stop(&d->bd_callout);
 	timed_out = (d->bd_state == BPF_TIMED_OUT);
@@ -764,6 +773,20 @@
 }
 
 static int
+bpf_ready(struct bpf_d *d)
+{
+
+	BPFD_LOCK_ASSERT(d);
+
+	if (d->bd_hlen != 0)
+		return (1);
+	if ((d->bd_immediate || d->bd_state == BPF_TIMED_OUT) &&
+	    d->bd_slen != 0)
+		return (1);
+	return (0);
+}
+
+static int
 bpfwrite(struct cdev *dev, struct uio *uio, int ioflag)
 {
 	struct bpf_d *d = dev->si_drv1;

==== //depot/projects/zcopybpf/src/sys/net/bpfdesc.h#4 (text+ko) ====

@@ -108,12 +108,6 @@
 	NET_ASSERT_GIANT();					\
 } while (0)
 
-/* Test whether a BPF is ready for read(). */
-#define	bpf_ready(bd)						 \
-	((bd)->bd_hlen != 0 ||					 \
-	 (((bd)->bd_immediate || (bd)->bd_state == BPF_TIMED_OUT) && \
-	  (bd)->bd_slen != 0))
-
 /*
  * External representation of the bpf descriptor
  */