1 /*
2  *
3  *		SNMP MIB entries for the IP subsystem.
4  *
5  *		Alan Cox <gw4pts@gw4pts.ampr.org>
6  *
7  *		We don't chose to implement SNMP in the kernel (this would
8  *		be silly as SNMP is a pain in the backside in places). We do
9  *		however need to collect the MIB statistics and export them
10  *		out of /proc (eventually)
11  *
12  *		This program is free software; you can redistribute it and/or
13  *		modify it under the terms of the GNU General Public License
14  *		as published by the Free Software Foundation; either version
15  *		2 of the License, or (at your option) any later version.
16  *
17  */
18 
19 #ifndef _SNMP_H
20 #define _SNMP_H
21 
22 #include <linux/cache.h>
23 #include <linux/snmp.h>
24 #include <linux/smp.h>
25 
26 /*
27  * Mibs are stored in array of unsigned long.
28  */
29 /*
30  * struct snmp_mib{}
31  *  - list of entries for particular API (such as /proc/net/snmp)
32  *  - name of entries.
33  */
34 struct snmp_mib {
35 	const char *name;
36 	int entry;
37 };
38 
39 #define SNMP_MIB_ITEM(_name,_entry)	{	\
40 	.name = _name,				\
41 	.entry = _entry,			\
42 }
43 
44 #define SNMP_MIB_SENTINEL {	\
45 	.name = NULL,		\
46 	.entry = 0,		\
47 }
48 
49 /*
50  * We use unsigned longs for most mibs but u64 for ipstats.
51  */
52 #include <linux/u64_stats_sync.h>
53 
54 /* IPstats */
55 #define IPSTATS_MIB_MAX	__IPSTATS_MIB_MAX
56 struct ipstats_mib {
57 	/* mibs[] must be first field of struct ipstats_mib */
58 	u64		mibs[IPSTATS_MIB_MAX];
59 	struct u64_stats_sync syncp;
60 };
61 
62 /* ICMP */
63 #define ICMP_MIB_MAX	__ICMP_MIB_MAX
64 struct icmp_mib {
65 	unsigned long	mibs[ICMP_MIB_MAX];
66 };
67 
68 #define ICMPMSG_MIB_MAX	__ICMPMSG_MIB_MAX
69 struct icmpmsg_mib {
70 	atomic_long_t	mibs[ICMPMSG_MIB_MAX];
71 };
72 
73 /* ICMP6 (IPv6-ICMP) */
74 #define ICMP6_MIB_MAX	__ICMP6_MIB_MAX
75 /* per network ns counters */
76 struct icmpv6_mib {
77 	unsigned long	mibs[ICMP6_MIB_MAX];
78 };
79 /* per device counters, (shared on all cpus) */
80 struct icmpv6_mib_device {
81 	atomic_long_t	mibs[ICMP6_MIB_MAX];
82 };
83 
84 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
85 /* per network ns counters */
86 struct icmpv6msg_mib {
87 	atomic_long_t	mibs[ICMP6MSG_MIB_MAX];
88 };
89 /* per device counters, (shared on all cpus) */
90 struct icmpv6msg_mib_device {
91 	atomic_long_t	mibs[ICMP6MSG_MIB_MAX];
92 };
93 
94 
95 /* TCP */
96 #define TCP_MIB_MAX	__TCP_MIB_MAX
97 struct tcp_mib {
98 	unsigned long	mibs[TCP_MIB_MAX];
99 };
100 
101 /* UDP */
102 #define UDP_MIB_MAX	__UDP_MIB_MAX
103 struct udp_mib {
104 	unsigned long	mibs[UDP_MIB_MAX];
105 };
106 
107 /* Linux */
108 #define LINUX_MIB_MAX	__LINUX_MIB_MAX
109 struct linux_mib {
110 	unsigned long	mibs[LINUX_MIB_MAX];
111 };
112 
113 /* Linux Xfrm */
114 #define LINUX_MIB_XFRMMAX	__LINUX_MIB_XFRMMAX
115 struct linux_xfrm_mib {
116 	unsigned long	mibs[LINUX_MIB_XFRMMAX];
117 };
118 
119 #define DEFINE_SNMP_STAT(type, name)	\
120 	__typeof__(type) __percpu *name
121 #define DEFINE_SNMP_STAT_ATOMIC(type, name)	\
122 	__typeof__(type) *name
123 #define DECLARE_SNMP_STAT(type, name)	\
124 	extern __typeof__(type) __percpu *name
125 
126 #define __SNMP_INC_STATS(mib, field)	\
127 			__this_cpu_inc(mib->mibs[field])
128 
129 #define SNMP_INC_STATS_ATOMIC_LONG(mib, field)	\
130 			atomic_long_inc(&mib->mibs[field])
131 
132 #define SNMP_INC_STATS(mib, field)	\
133 			this_cpu_inc(mib->mibs[field])
134 
135 #define SNMP_DEC_STATS(mib, field)	\
136 			this_cpu_dec(mib->mibs[field])
137 
138 #define __SNMP_ADD_STATS(mib, field, addend)	\
139 			__this_cpu_add(mib->mibs[field], addend)
140 
141 #define SNMP_ADD_STATS(mib, field, addend)	\
142 			this_cpu_add(mib->mibs[field], addend)
143 #define SNMP_UPD_PO_STATS(mib, basefield, addend)	\
144 	do { \
145 		__typeof__((mib->mibs) + 0) ptr = mib->mibs;	\
146 		this_cpu_inc(ptr[basefield##PKTS]);		\
147 		this_cpu_add(ptr[basefield##OCTETS], addend);	\
148 	} while (0)
149 #define __SNMP_UPD_PO_STATS(mib, basefield, addend)	\
150 	do { \
151 		__typeof__((mib->mibs) + 0) ptr = mib->mibs;	\
152 		__this_cpu_inc(ptr[basefield##PKTS]);		\
153 		__this_cpu_add(ptr[basefield##OCTETS], addend);	\
154 	} while (0)
155 
156 
157 #if BITS_PER_LONG==32
158 
159 #define __SNMP_ADD_STATS64(mib, field, addend) 				\
160 	do {								\
161 		__typeof__(*mib) *ptr = raw_cpu_ptr(mib);		\
162 		u64_stats_update_begin(&ptr->syncp);			\
163 		ptr->mibs[field] += addend;				\
164 		u64_stats_update_end(&ptr->syncp);			\
165 	} while (0)
166 
167 #define SNMP_ADD_STATS64(mib, field, addend) 				\
168 	do {								\
169 		local_bh_disable();					\
170 		__SNMP_ADD_STATS64(mib, field, addend);			\
171 		local_bh_enable();				\
172 	} while (0)
173 
174 #define __SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
175 #define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
176 #define __SNMP_UPD_PO_STATS64(mib, basefield, addend)			\
177 	do {								\
178 		__typeof__(*mib) *ptr;				\
179 		ptr = raw_cpu_ptr((mib));				\
180 		u64_stats_update_begin(&ptr->syncp);			\
181 		ptr->mibs[basefield##PKTS]++;				\
182 		ptr->mibs[basefield##OCTETS] += addend;			\
183 		u64_stats_update_end(&ptr->syncp);			\
184 	} while (0)
185 #define SNMP_UPD_PO_STATS64(mib, basefield, addend)			\
186 	do {								\
187 		local_bh_disable();					\
188 		__SNMP_UPD_PO_STATS64(mib, basefield, addend);		\
189 		local_bh_enable();				\
190 	} while (0)
191 #else
192 #define __SNMP_INC_STATS64(mib, field)		__SNMP_INC_STATS(mib, field)
193 #define SNMP_INC_STATS64(mib, field)		SNMP_INC_STATS(mib, field)
194 #define SNMP_DEC_STATS64(mib, field)		SNMP_DEC_STATS(mib, field)
195 #define __SNMP_ADD_STATS64(mib, field, addend)	__SNMP_ADD_STATS(mib, field, addend)
196 #define SNMP_ADD_STATS64(mib, field, addend)	SNMP_ADD_STATS(mib, field, addend)
197 #define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
198 #define __SNMP_UPD_PO_STATS64(mib, basefield, addend) __SNMP_UPD_PO_STATS(mib, basefield, addend)
199 #endif
200 
201 #endif
202