net: fix /proc/net/ip_mr_cache display - V2

/proc/net/ip_mr_cache and /proc/net/ip6_mr_cache displays garbage when
showing unresolved mfc_cache entries.

[root@qemu tests]# cat /proc/net/ip_mr_cache
Group    Origin   Iif     Pkts    Bytes    Wrong Oifs
014C00EF 010014AC 1         10    10050        0  2:1    3:1
024C00EF 010014AC 65535      514        2 -559067475

The first line is correct. It is a resolved cache entry, 10 packets used it...
The second line represents an unresolved entry, and the columns Pkts(4th),
Bytes(5th) and Wrong(6th) just show garbage.

In struct mfc_cache, there's an union to store data for resolved and
unresolved cases. And what ipmr_mfc_seq_show() is printing in these
columns for the unresolved entries is some bytes from mfc_cache.mfc_un.res.
Bad.
(eg. In our case -559067475 is in fact 0xdead4ead which is the spinlock
magic from mfc_cache.mfc_un.unres.unresolved.lock.magic).

This patch replaces the garbage data written in these columns for the
unresolved entries by '0' (zeros) which is more correct.
This change doesn't break the ABI.

Also, mfc->mfc_un.res.pkt, mfc->mfc_un.res.bytes, mfc->mfc_un.res.wrong_if
are unsigned long.

It applies on top of net-next-2.6.

The patch for net-2.6 is slightly different because of the NIP6_FMT to
%pI6 conversion that was made in the seq_printf.

Changelog:
==========
V2:
* Instead of breaking the ABI by suppressing the columns that have no
  meaning for unresolved entries, fill them with 0 values.

Signed-off-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 77fc4d3fdf6129aa90ddf794c8fffa32ed56b548..cb3a57d46af64f2cb60496a994def922a4cd9565 100644 (file)
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1879,15 +1879,16 @@ 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 %8ld %8ld %8ld",
+               seq_printf(seq, "%08lX %08lX %-3d",
                           (unsigned long) mfc->mfc_mcastgrp,
                           (unsigned long) mfc->mfc_origin,
-                          mfc->mfc_parent,
-                          mfc->mfc_un.res.pkt,
-                          mfc->mfc_un.res.bytes,
-                          mfc->mfc_un.res.wrong_if);
+                          mfc->mfc_parent);
 
                if (it->cache != &mfc_unres_queue) {
+                       seq_printf(seq, " %8lu %8lu %8lu",
+                                  mfc->mfc_un.res.pkt,
+                                  mfc->mfc_un.res.bytes,
+                                  mfc->mfc_un.res.wrong_if);
                        for (n = mfc->mfc_un.res.minvif;
                             n < mfc->mfc_un.res.maxvif; n++ ) {
                                if (VIF_EXISTS(n)
@@ -1896,6 +1897,11 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
                                           " %2d:%-3d",
                                           n, mfc->mfc_un.res.ttls[n]);
                        }
+               } else {
+                       /* unresolved mfc_caches don't contain
+                        * pkt, bytes and wrong_if values
+                        */
+                       seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
                }
                seq_putc(seq, '\n');
        }

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index dfba9fd0c248842a2b023c415e88e2c068fb32d0..2dc4b0190878068bbf8658b7c227f2ef7aea09f4 100644 (file)
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -297,14 +297,15 @@ 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 %8ld %8ld %8ld",
+               seq_printf(seq, "%pI6 %pI6 %-3d",
                           &mfc->mf6c_mcastgrp, &mfc->mf6c_origin,
-                          mfc->mf6c_parent,
-                          mfc->mfc_un.res.pkt,
-                          mfc->mfc_un.res.bytes,
-                          mfc->mfc_un.res.wrong_if);
+                          mfc->mf6c_parent);
 
                if (it->cache != &mfc_unres_queue) {
+                       seq_printf(seq, " %8lu %8lu %8lu",
+                                  mfc->mfc_un.res.pkt,
+                                  mfc->mfc_un.res.bytes,
+                                  mfc->mfc_un.res.wrong_if);
                        for (n = mfc->mfc_un.res.minvif;
                             n < mfc->mfc_un.res.maxvif; n++) {
                                if (MIF_EXISTS(n) &&
@@ -313,6 +314,11 @@ static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
                                                   " %2d:%-3d",
                                                   n, mfc->mfc_un.res.ttls[n]);
                        }
+               } else {
+                       /* unresolved mfc_caches don't contain
+                        * pkt, bytes and wrong_if values
+                        */
+                       seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
                }
                seq_putc(seq, '\n');
        }