1 /*
2 * Copyright (c) 2005-2007 Harm Schotanus
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following
13 * disclaimer in the documentation and/or other materials provided
14 * with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
19 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
20 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
24 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
26 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 *
29 */
30
31 /*
32 * Get current memory statistics in bytes; reports them back in symon_buf as
33 *
34 * real active : real total : free : [swap used : swap total]
35 */
36
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <inttypes.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43
44 #include "error.h"
45 #include "conf.h"
46 #include "symon.h"
47 #include "xmalloc.h"
48
49 #define ktob(size) ((size) << 10)
50
51 /* Globals for this module all start with me_ */
52 static void *me_buf = NULL;
53 static u_int64_t me_size = 0;
54 static u_int64_t me_maxsize = 0;
55 static u_int64_t me_stats[5];
56
57 void
init_mem(struct stream * st)58 init_mem(struct stream *st)
59 {
60 if (me_buf == NULL) {
61 me_maxsize = SYMON_MAX_OBJSIZE;
62 me_buf = xmalloc(me_maxsize);
63 }
64
65 info("started module mem(%.200s)", st->arg);
66 }
67
68 void
gets_mem()69 gets_mem()
70 {
71 int fd;
72 if ((fd = open("/proc/meminfo", O_RDONLY)) < 0) {
73 warning("cannot access /proc/meminfo: %.200s", strerror(errno));
74 }
75
76 bzero(me_buf, me_maxsize);
77 me_size = read(fd, me_buf, me_maxsize);
78 close(fd);
79
80 if (me_size == me_maxsize) {
81 /* buffer is too small to hold all memory data */
82 me_maxsize += SYMON_MAX_OBJSIZE;
83 if (me_maxsize > SYMON_MAX_OBJSIZE * SYMON_MAX_DOBJECTS) {
84 fatal("%s:%d: dynamic object limit (%d) exceeded for cp data",
85 __FILE__, __LINE__, SYMON_MAX_OBJSIZE * SYMON_MAX_DOBJECTS);
86 }
87 me_buf = xrealloc(me_buf, me_maxsize);
88 gets_mem();
89 return;
90 }
91
92 if (me_size == -1) {
93 warning("could not read if statistics from /proc/meminfo: %.200s", strerror(errno));
94 }
95 }
96
97 u_int64_t
mem_getitem(char * name)98 mem_getitem(char *name)
99 {
100 u_int64_t stat;
101 char *line;
102
103 if (me_size <= 0) {
104 return 0;
105 }
106
107 if ((line = strstr(me_buf, name)) == NULL) {
108 warning("could not find %s in /proc/meminfo", name);
109 return 0;
110 }
111
112 line += strlen(name);
113 if (1 < sscanf(line, ": %" SCNu64 " Kb", &stat)) {
114 warning("could not parse memory statistics");
115 return 0;
116 } else {
117 return stat;
118 }
119 }
120
121 int
get_mem(char * symon_buf,int maxlen,struct stream * st)122 get_mem(char *symon_buf, int maxlen, struct stream *st)
123 {
124 me_stats[0] = ktob(mem_getitem("Active"));
125 me_stats[1] = ktob(mem_getitem("MemTotal"));
126 me_stats[2] = ktob(mem_getitem("MemFree"));
127 me_stats[1] -= me_stats[2];
128 me_stats[3] = ktob(mem_getitem("SwapFree"));
129 me_stats[4] = ktob(mem_getitem("SwapTotal"));
130
131 me_stats[3] = me_stats[4] - me_stats[3];
132
133 return snpack(symon_buf, maxlen, st->arg, MT_MEM2,
134 me_stats[0], me_stats[1], me_stats[2],
135 me_stats[3], me_stats[4]);
136 }
137