1 /**
2 * collectd - src/wireless.c
3 * Copyright (C) 2006,2007 Florian octo Forster
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Florian octo Forster <octo at collectd.org>
25 **/
27 #include "collectd.h"
29 #include "common.h"
30 #include "plugin.h"
32 #if !KERNEL_LINUX
33 # error "No applicable input method."
34 #endif
36 #define WIRELESS_PROC_FILE "/proc/net/wireless"
38 #if 0
39 static double wireless_dbm_to_watt (double dbm)
40 {
41 double watt;
43 /*
44 * dbm = 10 * log_{10} (1000 * power / W)
45 * power = 10^(dbm/10) * W/1000
46 */
48 watt = pow (10.0, (dbm / 10.0)) / 1000.0;
50 return (watt);
51 }
52 #endif
54 static void wireless_submit (const char *plugin_instance, const char *type,
55 double value)
56 {
57 value_list_t vl = VALUE_LIST_INIT;
59 vl.values = &(value_t) { .gauge = value };
60 vl.values_len = 1;
61 sstrncpy (vl.plugin, "wireless", sizeof (vl.plugin));
62 sstrncpy (vl.plugin_instance, plugin_instance,
63 sizeof (vl.plugin_instance));
64 sstrncpy (vl.type, type, sizeof (vl.type));
66 plugin_dispatch_values (&vl);
67 } /* void wireless_submit */
69 #define POWER_MIN -90.0
70 #define POWER_MAX -50.0
71 static double wireless_percent_to_power (double quality)
72 {
73 assert ((quality >= 0.0) && (quality <= 100.0));
75 return ((quality * (POWER_MAX - POWER_MIN)) + POWER_MIN);
76 } /* double wireless_percent_to_power */
78 static int wireless_read (void)
79 {
80 #ifdef KERNEL_LINUX
81 FILE *fh;
82 char buffer[1024];
84 char *device;
85 double quality;
86 double power;
87 double noise;
89 char *fields[8];
90 int numfields;
92 int devices_found;
93 int len;
95 /* there are a variety of names for the wireless device */
96 if ((fh = fopen (WIRELESS_PROC_FILE, "r")) == NULL)
97 {
98 char errbuf[1024];
99 WARNING ("wireless: fopen: %s",
100 sstrerror (errno, errbuf, sizeof (errbuf)));
101 return (-1);
102 }
104 devices_found = 0;
105 while (fgets (buffer, sizeof (buffer), fh) != NULL)
106 {
107 char *endptr;
109 numfields = strsplit (buffer, fields, 8);
111 if (numfields < 5)
112 continue;
114 len = strlen (fields[0]) - 1;
115 if (len < 1)
116 continue;
117 if (fields[0][len] != ':')
118 continue;
119 fields[0][len] = '\0';
121 device = fields[0];
123 quality = strtod (fields[2], &endptr);
124 if (fields[2] == endptr)
125 quality = -1.0; /* invalid */
127 /* power [dBm] < 0.0 */
128 power = strtod (fields[3], &endptr);
129 if (fields[3] == endptr)
130 power = 1.0; /* invalid */
131 else if ((power >= 0.0) && (power <= 100.0))
132 power = wireless_percent_to_power (power);
133 else if ((power > 100.0) && (power <= 256.0))
134 power = power - 256.0;
135 else if (power > 0.0)
136 power = 1.0; /* invalid */
138 /* noise [dBm] < 0.0 */
139 noise = strtod (fields[4], &endptr);
140 if (fields[4] == endptr)
141 noise = 1.0; /* invalid */
142 else if ((noise >= 0.0) && (noise <= 100.0))
143 noise = wireless_percent_to_power (noise);
144 else if ((noise > 100.0) && (noise <= 256.0))
145 noise = noise - 256.0;
146 else if (noise > 0.0)
147 noise = 1.0; /* invalid */
149 wireless_submit (device, "signal_quality", quality);
150 wireless_submit (device, "signal_power", power);
151 wireless_submit (device, "signal_noise", noise);
153 devices_found++;
154 }
156 fclose (fh);
158 /* If no wireless devices are present return an error, so the plugin
159 * code delays our read function. */
160 if (devices_found == 0)
161 return (-1);
162 #endif /* KERNEL_LINUX */
164 return (0);
165 } /* int wireless_read */
167 void module_register (void)
168 {
169 plugin_register_read ("wireless", wireless_read);
170 } /* void module_register */