Attachment 57685 Details for Bug 87014 – BPFMTAP.difftxt

BPFMTAP.difftxt

BPFMTAP.difftxt (text/plain), 2.19 KB, created by Mark Gooderum on 2005-10-07 06:03:12 UTC

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Creator: Mark Gooderum

Created: 2005-10-07 06:03:12 UTC

Size: 2.19 KB

patch

obsolete

>--- /tmp/tmp.44835.0	Fri Oct  7 00:00:08 2005
>+++ freebsd5/sys/net/bpf.c	Thu Oct  6 16:34:36 2005
>@@ -81,20 +81,27 @@
> /*
>  * The default read buffer size is patchable.
>  */
> static int bpf_bufsize = 4096;
> SYSCTL_INT(_debug, OID_AUTO, bpf_bufsize, CTLFLAG_RW,
> 	&bpf_bufsize, 0, "");
> static int bpf_maxbufsize = BPF_MAXBUFSIZE;
> SYSCTL_INT(_debug, OID_AUTO, bpf_maxbufsize, CTLFLAG_RW,
> 	&bpf_maxbufsize, 0, "");
> 
>+static int bpf_nullhits;
>+static int bpf_donullfix = 1;
>+SYSCTL_INT(_debug, OID_AUTO, bpf_nullfix, CTLFLAG_RW,
>+	   &bpf_donullfix, 0, "Apply the BPF null BP workaround");
>+SYSCTL_INT(_debug, OID_AUTO, bpf_nullhits, CTLFLAG_RW,
>+	   &bpf_nullhits, 0, "# of bpf_mtap/2() workarounds fired");
>+
> /*
>  *  bpf_iflist is the list of interfaces; each corresponds to an ifnet
>  */
> static LIST_HEAD(, bpf_if)	bpf_iflist;
> static struct mtx	bpf_mtx;		/* bpf global lock */
> 
> static int	bpf_allocbufs(struct bpf_d *);
> static void	bpf_attachd(struct bpf_d *d, struct bpf_if *bp);
> static void	bpf_detachd(struct bpf_d *d);
> static void	bpf_freed(struct bpf_d *);
>@@ -1201,20 +1208,31 @@
>  */
> void
> bpf_mtap(bp, m)
> 	struct bpf_if *bp;
> 	struct mbuf *m;
> {
> 	struct bpf_d *d;
> 	u_int pktlen, slen;
> 
> 	/*
>+	 * We can sometimes be invoked w/NULL bp due to a small race in 
>+	 * BPF_MTAP(), see PR#xxxxx.
>+	 */
>+	if (bpf_donullfix) {
>+		if (!bp) {
>+			bpf_nullhits++;
>+			return;
>+		}
>+	}
>+
>+	/*
> 	 * Lockless read to avoid cost of locking the interface if there are
> 	 * no descriptors attached.
> 	 */
> 	if (LIST_EMPTY(&bp->bif_dlist))
> 		return;
> 
> 	pktlen = m_length(m, NULL);
> 	if (pktlen == m->m_len) {
> 		bpf_tap(bp, mtod(m, u_char *), pktlen);
> 		return;
>@@ -1245,20 +1263,31 @@
> void
> bpf_mtap2(bp, data, dlen, m)
> 	struct bpf_if *bp;
> 	void *data;
> 	u_int dlen;
> 	struct mbuf *m;
> {
> 	struct mbuf mb;
> 	struct bpf_d *d;
> 	u_int pktlen, slen;
>+
>+	/*
>+	 * We can sometimes be invoked w/NULL bp due to a small race in 
>+	 * BPF_MTAP2(), see PR#xxxxx.
>+	 */
>+	if (bpf_donullfix) {
>+		if (!bp) {
>+			bpf_nullhits++;
>+			return;
>+		}
>+	}
> 
> 	/*
> 	 * Lockless read to avoid cost of locking the interface if there are
> 	 * no descriptors attached.
> 	 */
> 	if (LIST_EMPTY(&bp->bif_dlist))
> 		return;
> 
> 	pktlen = m_length(m, NULL);
> 	/*

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Attachments on bug 87014: 57683 | 57684 | 57685