[XFRM]: Define packet dropping statistics.

This statistics is shown factor dropped by transformation
at /proc/net/xfrm_stat for developer.
It is a counter designed from current transformation source code
and defined as linux private MIB.

See Documentation/networking/xfrm_proc.txt for the detail.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/xfrm/Makefile

@@ -4,5 +4,6 @@
 
 obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
 		      xfrm_input.o xfrm_output.o xfrm_algo.o
+obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
 obj-$(CONFIG_XFRM_USER) += xfrm_user.o
 

net/xfrm/xfrm_policy.c

@@ -27,11 +27,19 @@
 #include <net/dst.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
+#ifdef CONFIG_XFRM_STATISTICS
+#include <net/snmp.h>
+#endif
 
 #include "xfrm_hash.h"
 
 int sysctl_xfrm_larval_drop __read_mostly;
 
+#ifdef CONFIG_XFRM_STATISTICS
+DEFINE_SNMP_STAT(struct linux_xfrm_mib, xfrm_statistics) __read_mostly;
+EXPORT_SYMBOL(xfrm_statistics);
+#endif
+
 DEFINE_MUTEX(xfrm_cfg_mutex);
 EXPORT_SYMBOL(xfrm_cfg_mutex);
 
@@ -2258,6 +2266,16 @@ static struct notifier_block xfrm_dev_notifier = {
 	0
 };
 
+#ifdef CONFIG_XFRM_STATISTICS
+static int __init xfrm_statistics_init(void)
+{
+	if (snmp_mib_init((void **)xfrm_statistics,
+			  sizeof(struct linux_xfrm_mib)) < 0)
+		return -ENOMEM;
+	return 0;
+}
+#endif
+
 static void __init xfrm_policy_init(void)
 {
 	unsigned int hmask, sz;
@@ -2294,9 +2312,15 @@ static void __init xfrm_policy_init(void)
 
 void __init xfrm_init(void)
 {
+#ifdef CONFIG_XFRM_STATISTICS
+	xfrm_statistics_init();
+#endif
 	xfrm_state_init();
 	xfrm_policy_init();
 	xfrm_input_init();
+#ifdef CONFIG_XFRM_STATISTICS
+	xfrm_proc_init();
+#endif
 }
 
 #ifdef CONFIG_AUDITSYSCALL

net/xfrm/xfrm_proc.c

@@ -0,0 +1,96 @@
+/*
+ * xfrm_proc.c
+ *
+ * Copyright (C)2006-2007 USAGI/WIDE Project
+ *
+ * Authors:	Masahide NAKAMURA <nakam@linux-ipv6.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <net/snmp.h>
+#include <net/xfrm.h>
+
+static struct snmp_mib xfrm_mib_list[] = {
+	SNMP_MIB_ITEM("XfrmInError", LINUX_MIB_XFRMINERROR),
+	SNMP_MIB_ITEM("XfrmInBufferError", LINUX_MIB_XFRMINBUFFERERROR),
+	SNMP_MIB_ITEM("XfrmInHdrError", LINUX_MIB_XFRMINHDRERROR),
+	SNMP_MIB_ITEM("XfrmInNoStates", LINUX_MIB_XFRMINNOSTATES),
+	SNMP_MIB_ITEM("XfrmInStateProtoError", LINUX_MIB_XFRMINSTATEPROTOERROR),
+	SNMP_MIB_ITEM("XfrmInStateModeError", LINUX_MIB_XFRMINSTATEMODEERROR),
+	SNMP_MIB_ITEM("XfrmInSeqOutOfWindow", LINUX_MIB_XFRMINSEQOUTOFWINDOW),
+	SNMP_MIB_ITEM("XfrmInStateExpired", LINUX_MIB_XFRMINSTATEEXPIRED),
+	SNMP_MIB_ITEM("XfrmInStateMismatch", LINUX_MIB_XFRMINSTATEMISMATCH),
+	SNMP_MIB_ITEM("XfrmInStateInvalid", LINUX_MIB_XFRMINSTATEINVALID),
+	SNMP_MIB_ITEM("XfrmInTmplMismatch", LINUX_MIB_XFRMINTMPLMISMATCH),
+	SNMP_MIB_ITEM("XfrmInNoPols", LINUX_MIB_XFRMINNOPOLS),
+	SNMP_MIB_ITEM("XfrmInPolBlock", LINUX_MIB_XFRMINPOLBLOCK),
+	SNMP_MIB_ITEM("XfrmInPolError", LINUX_MIB_XFRMINPOLERROR),
+	SNMP_MIB_ITEM("XfrmOutError", LINUX_MIB_XFRMOUTERROR),
+	SNMP_MIB_ITEM("XfrmOutBundleGenError", LINUX_MIB_XFRMOUTBUNDLEGENERROR),
+	SNMP_MIB_ITEM("XfrmOutBundleCheckError", LINUX_MIB_XFRMOUTBUNDLECHECKERROR),
+	SNMP_MIB_ITEM("XfrmOutNoStates", LINUX_MIB_XFRMOUTNOSTATES),
+	SNMP_MIB_ITEM("XfrmOutStateProtoError", LINUX_MIB_XFRMOUTSTATEPROTOERROR),
+	SNMP_MIB_ITEM("XfrmOutStateModeError", LINUX_MIB_XFRMOUTSTATEMODEERROR),
+	SNMP_MIB_ITEM("XfrmOutStateExpired", LINUX_MIB_XFRMOUTSTATEEXPIRED),
+	SNMP_MIB_ITEM("XfrmOutPolBlock", LINUX_MIB_XFRMOUTPOLBLOCK),
+	SNMP_MIB_ITEM("XfrmOutPolDead", LINUX_MIB_XFRMOUTPOLDEAD),
+	SNMP_MIB_ITEM("XfrmOutPolError", LINUX_MIB_XFRMOUTPOLERROR),
+	SNMP_MIB_SENTINEL
+};
+
+static unsigned long
+fold_field(void *mib[], int offt)
+{
+        unsigned long res = 0;
+        int i;
+
+        for_each_possible_cpu(i) {
+                res += *(((unsigned long *)per_cpu_ptr(mib[0], i)) + offt);
+                res += *(((unsigned long *)per_cpu_ptr(mib[1], i)) + offt);
+        }
+        return res;
+}
+
+static int xfrm_statistics_seq_show(struct seq_file *seq, void *v)
+{
+	int i;
+	for (i=0; xfrm_mib_list[i].name; i++)
+		seq_printf(seq, "%-24s\t%lu\n", xfrm_mib_list[i].name,
+			   fold_field((void **)xfrm_statistics,
+				      xfrm_mib_list[i].entry));
+	return 0;
+}
+
+static int xfrm_statistics_seq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, xfrm_statistics_seq_show, NULL);
+}
+
+static struct file_operations xfrm_statistics_seq_fops = {
+	.owner	 = THIS_MODULE,
+	.open	 = xfrm_statistics_seq_open,
+	.read	 = seq_read,
+	.llseek	 = seq_lseek,
+	.release = single_release,
+};
+
+int __init xfrm_proc_init(void)
+{
+	int rc = 0;
+
+	if (!proc_net_fops_create(&init_net, "xfrm_stat", S_IRUGO,
+				  &xfrm_statistics_seq_fops))
+		goto stat_fail;
+
+ out:
+	return rc;
+
+ stat_fail:
+	rc = -ENOMEM;
+	goto out;
+}