1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include <net-snmp/agent/hardware/memory.h>
#include <unistd.h>
#include <fcntl.h>
/*
* Try to use an initial size that will cover default cases. We aren't talking
* about huge files, so why fiddle about with reallocs?
* I checked /proc/meminfo sizes on 3 different systems: 598, 644, 654
*
* On newer systems, the size is up to around 930 (2.6.27 kernel)
* or 1160 (2.6.28 kernel)
*/
#define MEMINFO_INIT_SIZE 1279
#define MEMINFO_STEP_SIZE 256
#define MEMINFO_FILE "/proc/meminfo"
/*
* Load the latest memory usage statistics
*/
int netsnmp_mem_arch_load( netsnmp_cache *cache, void *magic ) {
int statfd;
static char *buff = NULL;
static int bsize = 0;
static int first = 1;
ssize_t bytes_read;
char *b;
unsigned long memtotal = 0, memfree = 0, memshared = 0,
buffers = 0, cached = 0,
swaptotal = 0, swapfree = 0;
netsnmp_memory_info *mem;
/*
* Retrieve the memory information from the underlying O/S...
*/
if ((statfd = open(MEMINFO_FILE, O_RDONLY, 0)) == -1) {
snmp_log_perror(MEMINFO_FILE);
return -1;
}
if (bsize == 0) {
bsize = MEMINFO_INIT_SIZE;
buff = (char*)malloc(bsize+1);
if (NULL == buff) {
snmp_log(LOG_ERR, "malloc failed\n");
close(statfd);
return -1;
}
}
while ((bytes_read = read(statfd, buff, bsize)) == bsize) {
b = (char*)realloc(buff, bsize + MEMINFO_STEP_SIZE + 1);
if (NULL == b) {
snmp_log(LOG_ERR, "malloc failed\n");
close(statfd);
return -1;
}
buff = b;
bsize += MEMINFO_STEP_SIZE;
DEBUGMSGTL(("mem", "/proc/meminfo buffer increased to %d\n", bsize));
close(statfd);
statfd = open(MEMINFO_FILE, O_RDONLY, 0);
if (statfd == -1) {
snmp_log_perror(MEMINFO_FILE);
return -1;
}
}
close(statfd);
if (bytes_read <= 0) {
snmp_log_perror(MEMINFO_FILE);
} else {
buff[bytes_read] = '\0';
}
/*
* ... parse this into a more useable form...
*/
b = strstr(buff, "MemTotal: ");
if (b)
sscanf(b, "MemTotal: %lu", &memtotal);
else {
if (first)
snmp_log(LOG_ERR, "No MemTotal line in /proc/meminfo\n");
}
b = strstr(buff, "MemFree: ");
if (b)
sscanf(b, "MemFree: %lu", &memfree);
else {
if (first)
snmp_log(LOG_ERR, "No MemFree line in /proc/meminfo\n");
}
if (0 == netsnmp_os_prematch("Linux","2.4")) {
b = strstr(buff, "MemShared: ");
if (b)
sscanf(b, "MemShared: %lu", &memshared);
else if (first)
snmp_log(LOG_ERR, "No MemShared line in /proc/meminfo\n");
}
else {
b = strstr(buff, "Shmem: ");
if (b)
sscanf(b, "Shmem: %lu", &memshared);
else if (first)
snmp_log(LOG_ERR, "No Shmem line in /proc/meminfo\n");
}
b = strstr(buff, "Buffers: ");
if (b)
sscanf(b, "Buffers: %lu", &buffers);
else {
if (first)
snmp_log(LOG_ERR, "No Buffers line in /proc/meminfo\n");
}
b = strstr(buff, "Cached: ");
if (b)
sscanf(b, "Cached: %lu", &cached);
else {
if (first)
snmp_log(LOG_ERR, "No Cached line in /proc/meminfo\n");
}
b = strstr(buff, "SwapTotal: ");
if (b)
sscanf(b, "SwapTotal: %lu", &swaptotal);
else {
if (first)
snmp_log(LOG_ERR, "No SwapTotal line in /proc/meminfo\n");
}
b = strstr(buff, "SwapFree: ");
if (b)
sscanf(b, "SwapFree: %lu", &swapfree);
else {
if (first)
snmp_log(LOG_ERR, "No SwapFree line in /proc/meminfo\n");
}
first = 0;
/*
* ... and save this in a standard form.
*/
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_PHYSMEM, 1 );
if (!mem) {
snmp_log_perror("No Physical Memory info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Physical memory");
mem->units = 1024;
mem->size = memtotal;
mem->free = memfree;
mem->other = -1;
}
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_VIRTMEM, 1 );
if (!mem) {
snmp_log_perror("No Virtual Memory info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Virtual memory");
mem->units = 1024;
mem->size = memtotal+swaptotal;
mem->free = memfree +swapfree;
mem->other = -1;
}
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SHARED, 1 );
if (!mem) {
snmp_log_perror("No Shared Memory info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Shared memory");
mem->units = 1024;
mem->size = memshared;
mem->free = 0; /* All in use */
mem->other = -1;
}
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_CACHED, 1 );
if (!mem) {
snmp_log_perror("No Cached Memory info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Cached memory");
mem->units = 1024;
mem->size = cached;
mem->free = 0; /* Report cached size/used as equal */
mem->other = -1;
}
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_SWAP, 1 );
if (!mem) {
snmp_log_perror("No Swap info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Swap space");
mem->units = 1024;
mem->size = swaptotal;
mem->free = swapfree;
mem->other = -1;
}
mem = netsnmp_memory_get_byIdx( NETSNMP_MEM_TYPE_MBUF, 1 );
if (!mem) {
snmp_log_perror("No Buffer, etc info entry");
} else {
if (!mem->descr)
mem->descr = strdup("Memory buffers");
mem->units = 1024;
mem->size = memtotal; /* Traditionally we've always regarded
all memory as potentially available
for memory buffers. */
mem->free = memtotal - buffers;
mem->other = -1;
}
return 0;
}
|
