1 /**
2 * collectd - src/uptime.c
3 * Copyright (C) 2009 Marco Chiappero
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Authors:
19 * Marco Chiappero <marco at absence.it>
20 **/
22 #include "collectd.h"
24 #include "common.h"
25 #include "plugin.h"
27 #if KERNEL_LINUX
28 # define STAT_FILE "/proc/stat"
29 /* Using /proc filesystem to retrieve the boot time, Linux only. */
30 /* #endif KERNEL_LINUX */
32 #elif HAVE_LIBKSTAT
33 /* Using kstats chain to retrieve the boot time on Solaris / OpenSolaris systems */
34 /* #endif HAVE_LIBKSTAT */
36 #elif HAVE_SYS_SYSCTL_H
37 # include <sys/sysctl.h>
38 /* Using sysctl interface to retrieve the boot time on *BSD / Darwin / OS X systems */
39 /* #endif HAVE_SYS_SYSCTL_H */
41 #elif HAVE_PERFSTAT
42 # include <sys/protosw.h>
43 # include <libperfstat.h>
44 /* Using perfstat_cpu_total to retrive the boot time in AIX */
45 /* #endif HAVE_PERFSTAT */
47 #else
48 # error "No applicable input method."
49 #endif
51 /*
52 * Global variables
53 */
54 /* boottime always used, no OS distinction */
55 static time_t boottime;
57 #if HAVE_LIBKSTAT
58 extern kstat_ctl_t *kc;
59 #endif /* #endif HAVE_LIBKSTAT */
61 static void uptime_submit (gauge_t value)
62 {
63 value_list_t vl = VALUE_LIST_INIT;
65 vl.values = &(value_t) { .gauge = value };
66 vl.values_len = 1;
68 sstrncpy (vl.plugin, "uptime", sizeof (vl.plugin));
69 sstrncpy (vl.type, "uptime", sizeof (vl.type));
71 plugin_dispatch_values (&vl);
72 }
74 static int uptime_init (void) /* {{{ */
75 {
76 /*
77 * On most unix systems the uptime is calculated by looking at the boot
78 * time (stored in unix time, since epoch) and the current one. We are
79 * going to do the same, reading the boot time value while executing
80 * the uptime_init function (there is no need to read, every time the
81 * plugin_read is called, a value that won't change). However, since
82 * uptime_init is run only once, if the function fails in retrieving
83 * the boot time, the plugin is unregistered and there is no chance to
84 * try again later. Nevertheless, this is very unlikely to happen.
85 */
87 #if KERNEL_LINUX
88 unsigned long starttime;
89 char buffer[1024];
90 int ret;
91 FILE *fh;
93 ret = 0;
95 fh = fopen (STAT_FILE, "r");
97 if (fh == NULL)
98 {
99 char errbuf[1024];
100 ERROR ("uptime plugin: Cannot open "STAT_FILE": %s",
101 sstrerror (errno, errbuf, sizeof (errbuf)));
102 return (-1);
103 }
105 while (fgets (buffer, 1024, fh) != NULL)
106 {
107 /* look for the btime string and read the value */
108 ret = sscanf (buffer, "btime %lu", &starttime);
109 /* avoid further loops if btime has been found and read
110 * correctly (hopefully) */
111 if (ret == 1)
112 break;
113 }
115 fclose (fh);
117 /* loop done, check if no value has been found/read */
118 if (ret != 1)
119 {
120 ERROR ("uptime plugin: No value read from "STAT_FILE"");
121 return (-1);
122 }
124 boottime = (time_t) starttime;
126 if (boottime == 0)
127 {
128 ERROR ("uptime plugin: btime read from "STAT_FILE", "
129 "but `boottime' is zero!");
130 return (-1);
131 }
132 /* #endif KERNEL_LINUX */
134 #elif HAVE_LIBKSTAT
135 kstat_t *ksp;
136 kstat_named_t *knp;
138 ksp = NULL;
139 knp = NULL;
141 /* kstats chain already opened by update_kstat (using *kc), verify everything went fine. */
142 if (kc == NULL)
143 {
144 ERROR ("uptime plugin: kstat chain control structure not available.");
145 return (-1);
146 }
148 ksp = kstat_lookup (kc, "unix", 0, "system_misc");
149 if (ksp == NULL)
150 {
151 ERROR ("uptime plugin: Cannot find unix:0:system_misc kstat.");
152 return (-1);
153 }
155 if (kstat_read (kc, ksp, NULL) < 0)
156 {
157 ERROR ("uptime plugin: kstat_read failed.");
158 return (-1);
159 }
161 knp = (kstat_named_t *) kstat_data_lookup (ksp, "boot_time");
162 if (knp == NULL)
163 {
164 ERROR ("uptime plugin: kstat_data_lookup (boot_time) failed.");
165 return (-1);
166 }
168 boottime = (time_t) knp->value.ui32;
170 if (boottime == 0)
171 {
172 ERROR ("uptime plugin: kstat_data_lookup returned success, "
173 "but `boottime' is zero!");
174 return (-1);
175 }
176 /* #endif HAVE_LIBKSTAT */
178 # elif HAVE_SYS_SYSCTL_H
179 struct timeval boottv = { 0 };
180 size_t boottv_len;
181 int status;
183 int mib[] = { CTL_KERN, KERN_BOOTTIME };
185 boottv_len = sizeof (boottv);
187 status = sysctl (mib, STATIC_ARRAY_SIZE (mib), &boottv, &boottv_len,
188 /* new_value = */ NULL, /* new_length = */ 0);
189 if (status != 0)
190 {
191 char errbuf[1024];
192 ERROR ("uptime plugin: No value read from sysctl interface: %s",
193 sstrerror (errno, errbuf, sizeof (errbuf)));
194 return (-1);
195 }
197 boottime = boottv.tv_sec;
199 if (boottime == 0)
200 {
201 ERROR ("uptime plugin: sysctl(3) returned success, "
202 "but `boottime' is zero!");
203 return (-1);
204 }
205 /* #endif HAVE_SYS_SYSCTL_H */
207 #elif HAVE_PERFSTAT
208 int status;
209 perfstat_cpu_total_t cputotal;
210 int hertz;
212 status = perfstat_cpu_total(NULL, &cputotal,
213 sizeof(perfstat_cpu_total_t), 1);
214 if (status < 0)
215 {
216 char errbuf[1024];
217 ERROR ("uptime plugin: perfstat_cpu_total: %s",
218 sstrerror (errno, errbuf, sizeof (errbuf)));
219 return (-1);
220 }
222 hertz = sysconf(_SC_CLK_TCK);
223 if (hertz <= 0)
224 hertz = HZ;
226 boottime = time(NULL) - cputotal.lbolt / hertz;
227 #endif /* HAVE_PERFSTAT */
229 return (0);
230 } /* }}} int uptime_init */
232 static int uptime_read (void)
233 {
234 gauge_t uptime;
235 time_t elapsed;
237 /* calculate the amount of time elapsed since boot, AKA uptime */
238 elapsed = time (NULL) - boottime;
240 uptime = (gauge_t) elapsed;
242 uptime_submit (uptime);
244 return (0);
245 }
247 void module_register (void)
248 {
249 plugin_register_init ("uptime", uptime_init);
250 plugin_register_read ("uptime", uptime_read);
251 } /* void module_register */