From e975b173f612fee4fbc04a7ffb270a6f064a8cf5 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Ritschard <pyr@spootnik.org>
Date: Tue, 29 Jul 2014 11:10:45 +0200
Subject: [PATCH] Support older conntrack files with an option

supersedes collectd/collectd#605
---
 src/collectd.conf.pod | 13 +++++++++++++
 src/conntrack.c       | 27 +++++++++++++++++++++++++--
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index 32ed9903..8b9157d9 100644
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -989,6 +989,19 @@ at all, B<all> cgroups are selected.
 
 =back
 
+=head2 Plugin C<conntrack>
+
+This plugin collects IP conntrack statistics.
+
+=over 4
+
+=item B<OldFiles>
+
+Assume the B<conntrack_count> and B<conntrack_max> files to be found in
+F</proc/sys/net/ipv4/netfilter> instead of F</proc/sys/net/netfilter/>.
+
+=back
+
 =head2 Plugin C<cpu>
 
 The I<CPU plugin> collects CPU usage metrics.
diff --git a/src/conntrack.c b/src/conntrack.c
index e7bccad3..b8f8dfd8 100644
--- a/src/conntrack.c
+++ b/src/conntrack.c
@@ -31,6 +31,27 @@
 
 #define CONNTRACK_FILE "/proc/sys/net/netfilter/nf_conntrack_count"
 #define CONNTRACK_MAX_FILE "/proc/sys/net/netfilter/nf_conntrack_max"
+#define CONNTRACK_FILE_OLD "/proc/sys/net/ipv4/netfilter/ip_conntrack_count"
+#define CONNTRACK_MAX_FILE_OLD "/proc/sys/net/ipv4/netfilter/ip_conntrack_max"
+
+static const char *config_keys[] =
+{
+	"OldFiles"
+};
+static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
+/*
+    Each table/chain combo that will be queried goes into this list
+*/
+
+static int old_files = 0;
+
+static int conntrack_config(const char *key, const char *value)
+{
+    if (strcmp(key, "OldFiles") == 0)
+        old_files = 1;
+
+    return 0;
+}
 
 static void conntrack_submit (const char *type, const char *type_instance,
 			      value_t conntrack)
@@ -56,7 +77,7 @@ static int conntrack_read (void)
 	char buffer[64];
 	size_t buffer_len;
 
-	fh = fopen (CONNTRACK_FILE, "r");
+	fh = fopen (old_files?CONNTRACK_FILE_OLD:CONNTRACK_FILE, "r");
 	if (fh == NULL)
 		return (-1);
 
@@ -81,7 +102,7 @@ static int conntrack_read (void)
 
 	conntrack_submit ("conntrack", NULL, conntrack);
 
-	fh = fopen (CONNTRACK_MAX_FILE, "r");
+	fh = fopen (old_files?CONNTRACK_MAX_FILE_OLD:CONNTRACK_MAX_FILE, "r");
 	if (fh == NULL)
 		return (-1);
 
@@ -114,5 +135,7 @@ static int conntrack_read (void)
 
 void module_register (void)
 {
+    plugin_register_config ("conntrack", conntrack_config,
+                            config_keys, config_keys_num);
 	plugin_register_read ("conntrack", conntrack_read);
 } /* void module_register */
-- 
2.30.2