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>
32 # error "No applicable input method."
35 #define WIRELESS_PROC_FILE "/proc/net/wireless"
38 static double wireless_dbm_to_watt (double dbm)
43 * dbm = 10 * log_{10} (1000 * power / W)
44 * power = 10^(dbm/10) * W/1000
47 watt = pow (10.0, (dbm / 10.0)) / 1000.0;
53 static void wireless_submit (const char *plugin_instance, const char *type,
57 value_list_t vl = VALUE_LIST_INIT;
59 values[0].gauge = value;
63 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
64 sstrncpy (vl.plugin, "wireless", sizeof (vl.plugin));
65 sstrncpy (vl.plugin_instance, plugin_instance,
66 sizeof (vl.plugin_instance));
67 sstrncpy (vl.type, type, sizeof (vl.type));
69 plugin_dispatch_values (&vl);
70 } /* void wireless_submit */
72 #define POWER_MIN -90.0
73 #define POWER_MAX -50.0
74 static double wireless_percent_to_power (double quality)
76 assert ((quality >= 0.0) && (quality <= 100.0));
78 return ((quality * (POWER_MAX - POWER_MIN)) + POWER_MIN);
79 } /* double wireless_percent_to_power */
81 static int wireless_read (void)
98 /* there are a variety of names for the wireless device */
99 if ((fh = fopen (WIRELESS_PROC_FILE, "r")) == NULL)
102 WARNING ("wireless: fopen: %s",
103 sstrerror (errno, errbuf, sizeof (errbuf)));
108 while (fgets (buffer, sizeof (buffer), fh) != NULL)
112 numfields = strsplit (buffer, fields, 8);
117 len = strlen (fields[0]) - 1;
120 if (fields[0][len] != ':')
122 fields[0][len] = '\0';
126 quality = strtod (fields[2], &endptr);
127 if (fields[2] == endptr)
128 quality = -1.0; /* invalid */
130 /* power [dBm] < 0.0 */
131 power = strtod (fields[3], &endptr);
132 if (fields[3] == endptr)
133 power = 1.0; /* invalid */
134 else if ((power >= 0.0) && (power <= 100.0))
135 power = wireless_percent_to_power (power);
136 else if ((power > 100.0) && (power <= 256.0))
137 power = power - 256.0;
138 else if (power > 0.0)
139 power = 1.0; /* invalid */
141 /* noise [dBm] < 0.0 */
142 noise = strtod (fields[4], &endptr);
143 if (fields[4] == endptr)
144 noise = 1.0; /* invalid */
145 else if ((noise >= 0.0) && (noise <= 100.0))
146 noise = wireless_percent_to_power (noise);
147 else if ((noise > 100.0) && (noise <= 256.0))
148 noise = noise - 256.0;
149 else if (noise > 0.0)
150 noise = 1.0; /* invalid */
152 wireless_submit (device, "signal_quality", quality);
153 wireless_submit (device, "signal_power", power);
154 wireless_submit (device, "signal_noise", noise);
161 /* If no wireless devices are present return an error, so the plugin
162 * code delays our read function. */
163 if (devices_found == 0)
165 #endif /* KERNEL_LINUX */
168 } /* int wireless_read */
170 void module_register (void)
172 plugin_register_read ("wireless", wireless_read);
173 } /* void module_register */