Commit 999890b2 authored by Benjamin Thery's avatar Benjamin Thery Committed by David S. Miller

net: /proc/net/ip_mr_cache, display Iif as a signed short

Today, iproute2 fails to show multicast forwarding unresolved cache
entries while scanning /proc/net/ip_mr_cache.

Indeed, it expects to see -1 in 'Iif' column to identify unresolved
entries but the kernel outputs 65535. It's a signed/unsigned issue:

'Iif', the source interface, is retrieved from member mfc_parent in
struct mfc_cache. mfc_parent is a vifi_t: unsigned short, but is
displayed in ipmr_mfc_seq_show() as "%-3d", signed integer.

In unresolevd entries, the 65535 value (0xFFFF) comes from this define:
#define ALL_VIFS    ((vifi_t)(-1))

That may explains why the guy who added support for this in iproute2
thought a -1 should be expected.

I don't know if this must be fixed in kernel or in iproute2. Who is
right? What is the correct API? How was it designed originally?

I let you decide if it should goes in the kernel or be fixed in iproute2.
Signed-off-by: default avatarBenjamin Thery <benjamin.thery@bull.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ea472e2
......@@ -1879,7 +1879,7 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
const struct mfc_cache *mfc = v;
const struct ipmr_mfc_iter *it = seq->private;
seq_printf(seq, "%08lX %08lX %-3d",
seq_printf(seq, "%08lX %08lX %-3hd",
(unsigned long) mfc->mfc_mcastgrp,
(unsigned long) mfc->mfc_origin,
mfc->mfc_parent);
......
......@@ -297,7 +297,7 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
const struct mfc6_cache *mfc = v;
const struct ipmr_mfc_iter *it = seq->private;
seq_printf(seq, "%pI6 %pI6 %-3d",
seq_printf(seq, "%pI6 %pI6 %-3hd",
&mfc->mf6c_mcastgrp, &mfc->mf6c_origin,
mfc->mf6c_parent);
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment