xref: /linux/include/net/snmp.h (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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_DUMMY	__ICMP_MIB_MAX
64 #define ICMP_MIB_MAX	(__ICMP_MIB_MAX + 1)
65 
66 struct icmp_mib {
67 	unsigned long	mibs[ICMP_MIB_MAX];
68 };
69 
70 #define ICMPMSG_MIB_MAX	__ICMPMSG_MIB_MAX
71 struct icmpmsg_mib {
72 	unsigned long	mibs[ICMPMSG_MIB_MAX];
73 };
74 
75 /* ICMP6 (IPv6-ICMP) */
76 #define ICMP6_MIB_MAX	__ICMP6_MIB_MAX
77 struct icmpv6_mib {
78 	unsigned long	mibs[ICMP6_MIB_MAX];
79 };
80 
81 #define ICMP6MSG_MIB_MAX  __ICMP6MSG_MIB_MAX
82 struct icmpv6msg_mib {
83 	unsigned long	mibs[ICMP6MSG_MIB_MAX];
84 };
85 
86 
87 /* TCP */
88 #define TCP_MIB_MAX	__TCP_MIB_MAX
89 struct tcp_mib {
90 	unsigned long	mibs[TCP_MIB_MAX];
91 };
92 
93 /* UDP */
94 #define UDP_MIB_MAX	__UDP_MIB_MAX
95 struct udp_mib {
96 	unsigned long	mibs[UDP_MIB_MAX];
97 };
98 
99 /* Linux */
100 #define LINUX_MIB_MAX	__LINUX_MIB_MAX
101 struct linux_mib {
102 	unsigned long	mibs[LINUX_MIB_MAX];
103 };
104 
105 /* Linux Xfrm */
106 #define LINUX_MIB_XFRMMAX	__LINUX_MIB_XFRMMAX
107 struct linux_xfrm_mib {
108 	unsigned long	mibs[LINUX_MIB_XFRMMAX];
109 };
110 
111 /*
112  * FIXME: On x86 and some other CPUs the split into user and softirq parts
113  * is not needed because addl $1,memory is atomic against interrupts (but
114  * atomic_inc would be overkill because of the lock cycles). Wants new
115  * nonlocked_atomic_inc() primitives -AK
116  */
117 #define DEFINE_SNMP_STAT(type, name)	\
118 	__typeof__(type) __percpu *name[2]
119 #define DECLARE_SNMP_STAT(type, name)	\
120 	extern __typeof__(type) __percpu *name[2]
121 
122 #define SNMP_STAT_BHPTR(name)	(name[0])
123 #define SNMP_STAT_USRPTR(name)	(name[1])
124 
125 #define SNMP_INC_STATS_BH(mib, field)	\
126 			__this_cpu_inc(mib[0]->mibs[field])
127 #define SNMP_INC_STATS_USER(mib, field)	\
128 			this_cpu_inc(mib[1]->mibs[field])
129 #define SNMP_INC_STATS(mib, field)	\
130 			this_cpu_inc(mib[!in_softirq()]->mibs[field])
131 #define SNMP_DEC_STATS(mib, field)	\
132 			this_cpu_dec(mib[!in_softirq()]->mibs[field])
133 #define SNMP_ADD_STATS_BH(mib, field, addend)	\
134 			__this_cpu_add(mib[0]->mibs[field], addend)
135 #define SNMP_ADD_STATS_USER(mib, field, addend)	\
136 			this_cpu_add(mib[1]->mibs[field], addend)
137 #define SNMP_ADD_STATS(mib, field, addend)	\
138 			this_cpu_add(mib[!in_softirq()]->mibs[field], addend)
139 /*
140  * Use "__typeof__(*mib[0]) *ptr" instead of "__typeof__(mib[0]) ptr"
141  * to make @ptr a non-percpu pointer.
142  */
143 #define SNMP_UPD_PO_STATS(mib, basefield, addend)	\
144 	do { \
145 		__typeof__(*mib[0]) *ptr; \
146 		preempt_disable(); \
147 		ptr = this_cpu_ptr((mib)[!in_softirq()]); \
148 		ptr->mibs[basefield##PKTS]++; \
149 		ptr->mibs[basefield##OCTETS] += addend;\
150 		preempt_enable(); \
151 	} while (0)
152 #define SNMP_UPD_PO_STATS_BH(mib, basefield, addend)	\
153 	do { \
154 		__typeof__(*mib[0]) *ptr = \
155 			__this_cpu_ptr((mib)[!in_softirq()]); \
156 		ptr->mibs[basefield##PKTS]++; \
157 		ptr->mibs[basefield##OCTETS] += addend;\
158 	} while (0)
159 
160 
161 #if BITS_PER_LONG==32
162 
163 #define SNMP_ADD_STATS64_BH(mib, field, addend) 			\
164 	do {								\
165 		__typeof__(*mib[0]) *ptr = __this_cpu_ptr((mib)[0]);	\
166 		u64_stats_update_begin(&ptr->syncp);			\
167 		ptr->mibs[field] += addend;				\
168 		u64_stats_update_end(&ptr->syncp);			\
169 	} while (0)
170 #define SNMP_ADD_STATS64_USER(mib, field, addend) 			\
171 	do {								\
172 		__typeof__(*mib[0]) *ptr;				\
173 		preempt_disable();					\
174 		ptr = __this_cpu_ptr((mib)[1]);				\
175 		u64_stats_update_begin(&ptr->syncp);			\
176 		ptr->mibs[field] += addend;				\
177 		u64_stats_update_end(&ptr->syncp);			\
178 		preempt_enable();					\
179 	} while (0)
180 #define SNMP_ADD_STATS64(mib, field, addend)				\
181 	do {								\
182 		__typeof__(*mib[0]) *ptr;				\
183 		preempt_disable();					\
184 		ptr = __this_cpu_ptr((mib)[!in_softirq()]);		\
185 		u64_stats_update_begin(&ptr->syncp);			\
186 		ptr->mibs[field] += addend;				\
187 		u64_stats_update_end(&ptr->syncp);			\
188 		preempt_enable();					\
189 	} while (0)
190 #define SNMP_INC_STATS64_BH(mib, field) SNMP_ADD_STATS64_BH(mib, field, 1)
191 #define SNMP_INC_STATS64_USER(mib, field) SNMP_ADD_STATS64_USER(mib, field, 1)
192 #define SNMP_INC_STATS64(mib, field) SNMP_ADD_STATS64(mib, field, 1)
193 #define SNMP_UPD_PO_STATS64(mib, basefield, addend)			\
194 	do {								\
195 		__typeof__(*mib[0]) *ptr;				\
196 		preempt_disable();					\
197 		ptr = __this_cpu_ptr((mib)[!in_softirq()]);		\
198 		u64_stats_update_begin(&ptr->syncp);			\
199 		ptr->mibs[basefield##PKTS]++;				\
200 		ptr->mibs[basefield##OCTETS] += addend;			\
201 		u64_stats_update_end(&ptr->syncp);			\
202 		preempt_enable();					\
203 	} while (0)
204 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend)			\
205 	do {								\
206 		__typeof__(*mib[0]) *ptr;				\
207 		ptr = __this_cpu_ptr((mib)[!in_softirq()]);		\
208 		u64_stats_update_begin(&ptr->syncp);			\
209 		ptr->mibs[basefield##PKTS]++;				\
210 		ptr->mibs[basefield##OCTETS] += addend;			\
211 		u64_stats_update_end(&ptr->syncp);			\
212 	} while (0)
213 #else
214 #define SNMP_INC_STATS64_BH(mib, field)		SNMP_INC_STATS_BH(mib, field)
215 #define SNMP_INC_STATS64_USER(mib, field)	SNMP_INC_STATS_USER(mib, field)
216 #define SNMP_INC_STATS64(mib, field)		SNMP_INC_STATS(mib, field)
217 #define SNMP_DEC_STATS64(mib, field)		SNMP_DEC_STATS(mib, field)
218 #define SNMP_ADD_STATS64_BH(mib, field, addend) SNMP_ADD_STATS_BH(mib, field, addend)
219 #define SNMP_ADD_STATS64_USER(mib, field, addend) SNMP_ADD_STATS_USER(mib, field, addend)
220 #define SNMP_ADD_STATS64(mib, field, addend)	SNMP_ADD_STATS(mib, field, addend)
221 #define SNMP_UPD_PO_STATS64(mib, basefield, addend) SNMP_UPD_PO_STATS(mib, basefield, addend)
222 #define SNMP_UPD_PO_STATS64_BH(mib, basefield, addend) SNMP_UPD_PO_STATS_BH(mib, basefield, addend)
223 #endif
224 
225 #endif
226