2 * collectd - src/wireless.c
3 * Copyright (C) 2006,2007 Florian octo Forster
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:
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
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.
24 * Florian octo Forster <octo at collectd.org>
33 #error "No applicable input method."
36 #define WIRELESS_PROC_FILE "/proc/net/wireless"
39 static double wireless_dbm_to_watt (double dbm)
44 * dbm = 10 * log_{10} (1000 * power / W)
45 * power = 10^(dbm/10) * W/1000
48 watt = pow (10.0, (dbm / 10.0)) / 1000.0;
54 static void wireless_submit(const char *plugin_instance, const char *type,
56 value_list_t vl = VALUE_LIST_INIT;
58 vl.values = &(value_t){.gauge = value};
60 sstrncpy(vl.plugin, "wireless", sizeof(vl.plugin));
61 sstrncpy(vl.plugin_instance, plugin_instance, sizeof(vl.plugin_instance));
62 sstrncpy(vl.type, type, sizeof(vl.type));
64 plugin_dispatch_values(&vl);
65 } /* void wireless_submit */
67 #define POWER_MIN -90.0
68 #define POWER_MAX -50.0
69 static double wireless_percent_to_power(double quality) {
70 assert((quality >= 0.0) && (quality <= 100.0));
72 return (quality * (POWER_MAX - POWER_MIN)) + POWER_MIN;
73 } /* double wireless_percent_to_power */
75 static int wireless_read(void) {
91 /* there are a variety of names for the wireless device */
92 if ((fh = fopen(WIRELESS_PROC_FILE, "r")) == NULL) {
93 WARNING("wireless: fopen: %s", STRERRNO);
98 while (fgets(buffer, sizeof(buffer), fh) != NULL) {
101 numfields = strsplit(buffer, fields, 8);
106 len = strlen(fields[0]) - 1;
109 if (fields[0][len] != ':')
111 fields[0][len] = '\0';
115 quality = strtod(fields[2], &endptr);
116 if (fields[2] == endptr)
117 quality = -1.0; /* invalid */
119 /* power [dBm] < 0.0 */
120 power = strtod(fields[3], &endptr);
121 if (fields[3] == endptr)
122 power = 1.0; /* invalid */
123 else if ((power >= 0.0) && (power <= 100.0))
124 power = wireless_percent_to_power(power);
125 else if ((power > 100.0) && (power <= 256.0))
126 power = power - 256.0;
127 else if (power > 0.0)
128 power = 1.0; /* invalid */
130 /* noise [dBm] < 0.0 */
131 noise = strtod(fields[4], &endptr);
132 if (fields[4] == endptr)
133 noise = 1.0; /* invalid */
134 else if ((noise >= 0.0) && (noise <= 100.0))
135 noise = wireless_percent_to_power(noise);
136 else if ((noise > 100.0) && (noise <= 256.0))
137 noise = noise - 256.0;
138 else if (noise > 0.0)
139 noise = 1.0; /* invalid */
141 wireless_submit(device, "signal_quality", quality);
142 wireless_submit(device, "signal_power", power);
143 wireless_submit(device, "signal_noise", noise);
150 /* If no wireless devices are present return an error, so the plugin
151 * code delays our read function. */
152 if (devices_found == 0)
154 #endif /* KERNEL_LINUX */
157 } /* int wireless_read */
159 void module_register(void) {
160 plugin_register_read("wireless", wireless_read);
161 } /* void module_register */