1 files changed, 145 insertions, 0 deletions

diff --git a/include/net/snmp.h b/include/net/snmp.h
new file mode 100644
index 000000000000..a15ab256276e
--- /dev/null
+++ b/include/net/snmp.h
@@ -0,0 +1,145 @@
+/*
+ *
+ *              SNMP MIB entries for the IP subsystem.
+ *              
+ *              Alan Cox <gw4pts@gw4pts.ampr.org>
+ *
+ *              We don't chose to implement SNMP in the kernel (this would
+ *              be silly as SNMP is a pain in the backside in places). We do
+ *              however need to collect the MIB statistics and export them
+ *              out of /proc (eventually)
+ *
+ *              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.
+ *
+ *              $Id: snmp.h,v 1.19 2001/06/14 13:40:46 davem Exp $
+ *
+ */
+ 
+#ifndef _SNMP_H
+#define _SNMP_H
+
+#include <linux/cache.h>
+#include <linux/snmp.h>
+
+/*
+ * Mibs are stored in array of unsigned long.
+ */
+/*
+ * struct snmp_mib{}
+ *  - list of entries for particular API (such as /proc/net/snmp)
+ *  - name of entries.
+ */
+struct snmp_mib {
+        char *name;
+        int entry;
+};
+
+#define SNMP_MIB_ITEM(_name,_entry)     {       \
+        .name = _name,                          \
+        .entry = _entry,                        \
+}
+
+#define SNMP_MIB_SENTINEL {     \
+        .name = NULL,           \
+        .entry = 0,             \
+}
+
+/*
+ * We use all unsigned longs. Linux will soon be so reliable that even 
+ * these will rapidly get too small 8-). Seriously consider the IpInReceives 
+ * count on the 20Gb/s + networks people expect in a few years time!
+ */
+
+/* 
+ * The rule for padding: 
+ * Best is power of two because then the right structure can be found by a 
+ * simple shift. The structure should be always cache line aligned.
+ * gcc needs n=alignto(cachelinesize, popcnt(sizeof(bla_mib))) shift/add 
+ * instructions to emulate multiply in case it is not power-of-two. 
+ * Currently n is always <=3 for all sizes so simple cache line alignment 
+ * is enough. 
+ * 
+ * The best solution would be a global CPU local area , especially on 64 
+ * and 128byte cacheline machine it makes a *lot* of sense -AK
+ */ 
+
+#define __SNMP_MIB_ALIGN__      ____cacheline_aligned
+
+/* IPstats */
+#define IPSTATS_MIB_MAX __IPSTATS_MIB_MAX
+struct ipstats_mib {
+        unsigned long   mibs[IPSTATS_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* ICMP */
+#define ICMP_MIB_DUMMY  __ICMP_MIB_MAX
+#define ICMP_MIB_MAX    (__ICMP_MIB_MAX + 1)
+
+struct icmp_mib {
+        unsigned long   mibs[ICMP_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* ICMP6 (IPv6-ICMP) */
+#define ICMP6_MIB_MAX   __ICMP6_MIB_MAX
+struct icmpv6_mib {
+        unsigned long   mibs[ICMP6_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* TCP */
+#define TCP_MIB_MAX     __TCP_MIB_MAX
+struct tcp_mib {
+        unsigned long   mibs[TCP_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* UDP */
+#define UDP_MIB_MAX     __UDP_MIB_MAX
+struct udp_mib {
+        unsigned long   mibs[UDP_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* SCTP */
+#define SCTP_MIB_MAX    __SCTP_MIB_MAX
+struct sctp_mib {
+        unsigned long   mibs[SCTP_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
+/* Linux */
+#define LINUX_MIB_MAX   __LINUX_MIB_MAX
+struct linux_mib {
+        unsigned long   mibs[LINUX_MIB_MAX];
+};
+
+
+/* 
+ * FIXME: On x86 and some other CPUs the split into user and softirq parts
+ * is not needed because addl $1,memory is atomic against interrupts (but 
+ * atomic_inc would be overkill because of the lock cycles). Wants new 
+ * nonlocked_atomic_inc() primitives -AK
+ */ 
+#define DEFINE_SNMP_STAT(type, name)    \
+        __typeof__(type) *name[2]
+#define DECLARE_SNMP_STAT(type, name)   \
+        extern __typeof__(type) *name[2]
+
+#define SNMP_STAT_BHPTR(name)   (name[0])
+#define SNMP_STAT_USRPTR(name)  (name[1])
+
+#define SNMP_INC_STATS_BH(mib, field)   \
+        (per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field]++)
+#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset)    \
+        (per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field + (offset)]++)
+#define SNMP_INC_STATS_USER(mib, field) \
+        (per_cpu_ptr(mib[1], _smp_processor_id())->mibs[field]++)
+#define SNMP_INC_STATS(mib, field)      \
+        (per_cpu_ptr(mib[!in_softirq()], _smp_processor_id())->mibs[field]++)
+#define SNMP_DEC_STATS(mib, field)      \
+        (per_cpu_ptr(mib[!in_softirq()], _smp_processor_id())->mibs[field]--)
+#define SNMP_ADD_STATS_BH(mib, field, addend)   \
+        (per_cpu_ptr(mib[0], _smp_processor_id())->mibs[field] += addend)
+#define SNMP_ADD_STATS_USER(mib, field, addend)         \
+        (per_cpu_ptr(mib[1], _smp_processor_id())->mibs[field] += addend)
+
+#endif