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 value_t values[1];
57 value_list_t vl = VALUE_LIST_INIT;
59 values[0].gauge = value;
61 vl.values = values;
62 vl.values_len = 1;
63 sstrncpy(vl.host, hostname_g, sizeof(vl.host));
64 sstrncpy(vl.plugin, "wireless", sizeof(vl.plugin));
65 sstrncpy(vl.plugin_instance, plugin_instance, sizeof(vl.plugin_instance));
66 sstrncpy(vl.type, type, sizeof(vl.type));
68 plugin_dispatch_values(&vl);
69 } /* void wireless_submit */
71 #define POWER_MIN -90.0
72 #define POWER_MAX -50.0
73 static double wireless_percent_to_power(double quality) {
74 assert((quality >= 0.0) && (quality <= 100.0));
76 return ((quality * (POWER_MAX - POWER_MIN)) + POWER_MIN);
77 } /* double wireless_percent_to_power */
79 static int wireless_read(void) {
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 char errbuf[1024];
98 WARNING("wireless: fopen: %s", sstrerror(errno, errbuf, sizeof(errbuf)));
99 return (-1);
100 }
102 devices_found = 0;
103 while (fgets(buffer, sizeof(buffer), fh) != NULL) {
104 char *endptr;
106 numfields = strsplit(buffer, fields, 8);
108 if (numfields < 5)
109 continue;
111 len = strlen(fields[0]) - 1;
112 if (len < 1)
113 continue;
114 if (fields[0][len] != ':')
115 continue;
116 fields[0][len] = '\0';
118 device = fields[0];
120 quality = strtod(fields[2], &endptr);
121 if (fields[2] == endptr)
122 quality = -1.0; /* invalid */
124 /* power [dBm] < 0.0 */
125 power = strtod(fields[3], &endptr);
126 if (fields[3] == endptr)
127 power = 1.0; /* invalid */
128 else if ((power >= 0.0) && (power <= 100.0))
129 power = wireless_percent_to_power(power);
130 else if ((power > 100.0) && (power <= 256.0))
131 power = power - 256.0;
132 else if (power > 0.0)
133 power = 1.0; /* invalid */
135 /* noise [dBm] < 0.0 */
136 noise = strtod(fields[4], &endptr);
137 if (fields[4] == endptr)
138 noise = 1.0; /* invalid */
139 else if ((noise >= 0.0) && (noise <= 100.0))
140 noise = wireless_percent_to_power(noise);
141 else if ((noise > 100.0) && (noise <= 256.0))
142 noise = noise - 256.0;
143 else if (noise > 0.0)
144 noise = 1.0; /* invalid */
146 wireless_submit(device, "signal_quality", quality);
147 wireless_submit(device, "signal_power", power);
148 wireless_submit(device, "signal_noise", noise);
150 devices_found++;
151 }
153 fclose(fh);
155 /* If no wireless devices are present return an error, so the plugin
156 * code delays our read function. */
157 if (devices_found == 0)
158 return (-1);
159 #endif /* KERNEL_LINUX */
161 return (0);
162 } /* int wireless_read */
164 void module_register(void) {
165 plugin_register_read("wireless", wireless_read);
166 } /* void module_register */