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From: Phil Sutter <phil@nwl.cc>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Subject: [iptables PATCH 3/3] libxt_SECMARK: Fix for failing target comparison
Date: Tue, 12 May 2020 19:10:18 +0200	[thread overview]
Message-ID: <20200512171018.16871-4-phil@nwl.cc> (raw)
In-Reply-To: <20200512171018.16871-1-phil@nwl.cc>

The kernel fills in structxt_secmark_target_info->secid, so when the
rule is received from kernel it won't match a newly created one. This
prevented delete by rulespec and check commands.

Make use of newly introduced matchmask callback to prepare a mask which
explicitly excludes the secid field.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 extensions/libxt_SECMARK.c | 10 ++++++++++
 extensions/libxt_SECMARK.t |  4 ++++
 2 files changed, 14 insertions(+)
 create mode 100644 extensions/libxt_SECMARK.t

diff --git a/extensions/libxt_SECMARK.c b/extensions/libxt_SECMARK.c
index 6ba8606355daa..e9fd133642f00 100644
--- a/extensions/libxt_SECMARK.c
+++ b/extensions/libxt_SECMARK.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
  */
 #include <stdio.h>
+#include <string.h>
 #include <xtables.h>
 #include <linux/netfilter/xt_SECMARK.h>
 
@@ -68,6 +69,14 @@ static void SECMARK_save(const void *ip, const struct xt_entry_target *target)
 	print_secmark(info);
 }
 
+static void SECMARK_matchmask(void *mask)
+{
+	struct xt_secmark_target_info *info = mask;
+
+	memset(mask, 0xFF, XT_ALIGN(sizeof(struct xt_secmark_target_info)));
+	info->secid = 0;
+}
+
 static struct xtables_target secmark_target = {
 	.family		= NFPROTO_UNSPEC,
 	.name		= "SECMARK",
@@ -80,6 +89,7 @@ static struct xtables_target secmark_target = {
 	.save		= SECMARK_save,
 	.x6_parse	= SECMARK_parse,
 	.x6_options	= SECMARK_opts,
+	.matchmask	= SECMARK_matchmask,
 };
 
 void _init(void)
diff --git a/extensions/libxt_SECMARK.t b/extensions/libxt_SECMARK.t
new file mode 100644
index 0000000000000..39d4c09348bf4
--- /dev/null
+++ b/extensions/libxt_SECMARK.t
@@ -0,0 +1,4 @@
+:INPUT,FORWARD,OUTPUT
+*security
+-j SECMARK --selctx system_u:object_r:firewalld_exec_t:s0;=;OK
+-j SECMARK;;FAIL
-- 
2.25.1


  parent reply	other threads:[~2020-05-12 17:10 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-12 17:10 [iptables PATCH 0/3] Fix SECMARK target comparison Phil Sutter
2020-05-12 17:10 ` [iptables PATCH 1/3] xshared: Share make_delete_mask() between ip{,6}tables Phil Sutter
2020-05-12 17:10 ` [iptables PATCH 2/3] libxtables: Introduce 'matchmask' target callback Phil Sutter
2020-05-12 17:10 ` Phil Sutter [this message]
2020-05-14 12:23 ` [iptables PATCH 0/3] Fix SECMARK target comparison Pablo Neira Ayuso
2020-05-14 13:09   ` Phil Sutter

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