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 SNMP_ARRAY_SZ 1
120 
121 #define DEFINE_SNMP_STAT(type, name)	\
122 	__typeof__(type) __percpu *name[SNMP_ARRAY_SZ]
123 #define DEFINE_SNMP_STAT_ATOMIC(type, name)	\
124 	__typeof__(type) *name
125 #define DECLARE_SNMP_STAT(type, name)	\
126 	extern __typeof__(type) __percpu *name[SNMP_ARRAY_SZ]
127 
128 #define SNMP_INC_STATS_BH(mib, field)	\
129 			__this_cpu_inc(mib[0]->mibs[field])
130 
131 #define SNMP_INC_STATS_USER(mib, field)	\
132 			this_cpu_inc(mib[0]->mibs[field])
133 
134 #define SNMP_INC_STATS_ATOMIC_LONG(mib, field)	\
135 			atomic_long_inc(&mib->mibs[field])
136 
137 #define SNMP_INC_STATS(mib, field)	\
138 			this_cpu_inc(mib[0]->mibs[field])
139 
140 #define SNMP_DEC_STATS(mib, field)	\
141 			this_cpu_dec(mib[0]->mibs[field])
142 
143 #define SNMP_ADD_STATS_BH(mib, field, addend)	\
144 			__this_cpu_add(mib[0]->mibs[field], addend)
145 
146 #define SNMP_ADD_STATS_USER(mib, field, addend)	\
147 			this_cpu_add(mib[0]->mibs[field], addend)
148 
149 #define SNMP_ADD_STATS(mib, field, addend)	\
150 			this_cpu_add(mib[0]->mibs[field], addend)
151 /*
152  * Use "__typeof__(*mib[0]) *ptr" instead of "__typeof__(mib[0]) ptr"
153  * to make @ptr a non-percpu pointer.
154  */
155 #define SNMP_UPD_PO_STATS(mib, basefield, addend)	\
156 	do { \
157 		this_cpu_inc(mib[0]->mibs[basefield##PKTS]);		\
158 		this_cpu_add(mib[0]->mibs[basefield##OCTETS], addend);	\
159 	} while (0)
160 #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)	\
161 	do { \
162 		__this_cpu_inc(mib[0]->mibs[basefield##PKTS]);		\
163 		__this_cpu_add(mib[0]->mibs[basefield##OCTETS], addend);	\
164 	} while (0)
165 
166 
167 #if BITS_PER_LONG==32
168 
169 #define SNMP_ADD_STATS64_BH(mib, field, addend) 			\
170 	do {								\
171 		__typeof__(*mib[0]) *ptr = __this_cpu_ptr((mib)[0]);	\
172 		u64_stats_update_begin(&ptr->syncp);			\
173 		ptr->mibs[field] += addend;				\
174 		u64_stats_update_end(&ptr->syncp);			\
175 	} while (0)
176 
177 #define SNMP_ADD_STATS64_USER(mib, field, addend) 			\
178 	do {								\
179 		local_bh_disable();					\
180 		SNMP_ADD_STATS64_BH(mib, field, addend);		\
181 		local_bh_enable();					\
182 	} while (0)
183 
184 #define SNMP_ADD_STATS64(mib, field, addend)				\
185 		SNMP_ADD_STATS64_USER(mib, field, addend)
186 
187 #define SNMP_INC_STATS64_BH(mib, field) SNMP_ADD_STATS64_BH(mib, field, 1)
188 #define SNMP_INC_STATS64_USER(mib, field) SNMP_ADD_STATS64_USER(mib, field, 1)
189 #define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
190 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend)			\
191 	do {								\
192 		__typeof__(*mib[0]) *ptr;				\
193 		ptr = __this_cpu_ptr((mib)[0]);				\
194 		u64_stats_update_begin(&ptr->syncp);			\
195 		ptr->mibs[basefield##PKTS]++;				\
196 		ptr->mibs[basefield##OCTETS] += addend;			\
197 		u64_stats_update_end(&ptr->syncp);			\
198 	} while (0)
199 #define SNMP_UPD_PO_STATS64(mib, basefield, addend)			\
200 	do {								\
201 		local_bh_disable();					\
202 		SNMP_UPD_PO_STATS64_BH(mib, basefield, addend);		\
203 		local_bh_enable();					\
204 	} while (0)
205 #else
206 #define SNMP_INC_STATS64_BH(mib, field)		SNMP_INC_STATS_BH(mib, field)
207 #define SNMP_INC_STATS64_USER(mib, field)	SNMP_INC_STATS_USER(mib, field)
208 #define SNMP_INC_STATS64(mib, field)		SNMP_INC_STATS(mib, field)
209 #define SNMP_DEC_STATS64(mib, field)		SNMP_DEC_STATS(mib, field)
210 #define SNMP_ADD_STATS64_BH(mib, field, addend) SNMP_ADD_STATS_BH(mib, field, addend)
211 #define SNMP_ADD_STATS64_USER(mib, field, addend) SNMP_ADD_STATS_USER(mib, field, addend)
212 #define SNMP_ADD_STATS64(mib, field, addend)	SNMP_ADD_STATS(mib, field, addend)
213 #define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
214 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
215 #endif
216 
217 #endif
218