net: fix /proc/net/ip_mr_cache display - V2 (1ea472e2) · Commits · 戴 / test

/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>

net/ipv4/ipmr.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -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_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);

		if (it->cache != &mfc_unres_queue) {
		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');
		}

net/ipv6/ip6mr.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -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->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);

		if (it->cache != &mfc_unres_queue) {
		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');
		}

Admin message