PiLEDlights/netledPi.c
2021-03-09 08:59:14 -05:00

299 lines
9.8 KiB
C

/**************************************************************************
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* For more information, please refer to <http://unlicense.org/>
*
* A network activity light for the Raspberry Pi, using an LED connected to a GPIO pin.
* Based on hddled.c - http://members.optusnet.com.au/foonly/whirlpool/code/hddled.c -
* This program uses the WiringPi library by Gordon Henderson - http://wiringpi.com/ - Thanks, Gordon!
*
*
* To compile:
* gcc -Wall -O3 -o netledPi netledPi.c -lwiringPi
*
* Options:
* -d, --detach Detach from terminal (become a daemon)
* -p, --pin=VALUE GPIO pin (using wiringPi numbering scheme) where LED is connected (default: 11)
* -r, --refresh=VALUE Refresh interval (default: 20 ms)
*
* GPIO pin ----|>|----[330]----+
* LED |
* ===
* Ground
*
* Default LED Pin - wiringPi pin 11 is BCM_GPIO 7, physical pin 26 on the Pi's P1 header.
* Note: This pin is also used for the SPI interface. If you have SPI add-ons connected,
* you'll have to use the -p option to change it to another, unused pin.
*/
#define NETDEVICES "/proc/net/dev"
#define _GNU_SOURCE
#include <argp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <pigpio.h>
static unsigned int o_refresh = 20; /* milliseconds */
static unsigned int o_gpiopin_tx = 2;
static unsigned int o_gpiopin_rx = 3;
static int o_detach = 0;
static volatile sig_atomic_t running = 1;
static char *line = NULL;
static size_t len = 0;
/* Update the TX LED */
void tx_led(int on) {
static int tx_current = 1; /* Ensure the LED turns off on first call */
if (tx_current == on)
return;
if (on)
gpioWrite( o_gpiopin_tx, PI_HIGH );
else
gpioWrite( o_gpiopin_tx, PI_LOW );
tx_current = on;
}
/* Update the RX LED */
void rx_led(int on) {
static int rx_current = 1; /* Ensure the LED turns off on first call */
if (rx_current == on)
return;
if (on)
gpioWrite( o_gpiopin_rx, PI_HIGH );
else
gpioWrite( o_gpiopin_rx, PI_LOW );
rx_current = on;
}
/* Reread the netdevices file */
int activity(FILE *netdevices) {
static unsigned int prev_inpackets, prev_outpackets;
unsigned int inpackets, outpackets;
unsigned int device_inpackets, device_outpackets;
int found_inpackets, found_outpackets;
int result;
char *ptr;
char device[32];
/* Go to the beginning of the netdevices file */
result = TEMP_FAILURE_RETRY(fseek(netdevices, 0L, SEEK_SET));
if (result) {
perror("Could not rewind " NETDEVICES);
return result;
}
/* Clear glibc's buffer */
result = TEMP_FAILURE_RETRY(fflush(netdevices));
if (result) {
perror("Could not flush input stream");
return result;
}
/* Extract the I/O stats */
inpackets = outpackets = 0;
found_inpackets = found_outpackets = 0;
device_inpackets = device_outpackets = 0;
while (getline(&line, &len, netdevices) != -1 && errno != EINTR) {
ptr = line;
while (*ptr == ' ') ptr++; // Skip leading spaces
if (sscanf(ptr, "%s %*u %u %*u %*u %*u %*u %*u %*u %*u %u %*u %*u %*u %*u %*u %*u", device, &device_inpackets, &device_outpackets)) {
if(strstr(device, "lo:")) continue; // Skip loopback interface
found_inpackets++;
found_outpackets++;
inpackets += device_inpackets;
outpackets += device_outpackets;
}
}
if (!found_inpackets || !found_outpackets) {
fprintf(stderr, "Could not find required lines in " NETDEVICES);
return -1;
}
/* Anything changed? */
if( prev_inpackets != inpackets )
rx_led( PI_HIGH );
else
rx_led( PI_LOW );
if( prev_outpackets != outpackets )
tx_led( PI_HIGH );
else
tx_led( PI_LOW );
prev_inpackets = inpackets;
prev_outpackets = outpackets;
return 0;
}
/* Signal handler -- break out of the main loop */
void shutdown(int sig) {
running = 0;
}
/* Argp parser function */
error_t parse_options(int key, char *arg, struct argp_state *state) {
switch (key) {
case 'd':
o_detach = 1;
break;
case 'r':
o_refresh = strtol(arg, NULL, 10);
if (o_refresh < 10)
argp_failure(state, EXIT_FAILURE, 0,
"refresh interval must be at least 10");
break;
case 3:
o_gpiopin_tx = strtol(arg, NULL, 10);
if ((o_gpiopin_tx < 0) || (o_gpiopin_tx > 29))
argp_failure(state, EXIT_FAILURE, 0,
"pin number must be between 0 and 29");
break;
case 4:
o_gpiopin_rx = strtol(arg, NULL, 10);
if ((o_gpiopin_rx < 0) || (o_gpiopin_rx > 29))
argp_failure(state, EXIT_FAILURE, 0,
"pin number must be between 0 and 29");
break;
}
return 0;
}
int main(int argc, char **argv) {
struct argp_option options[] = {
{ "detach", 'd', NULL, 0, "Detach from terminal" },
{ "tx" , 0, "VALUE", 0, "GPIO pin where LED is connected (transmit data) (default: BCM 2 physical pin 3 on the P1 header)" },
{ "rx", 1, "VALUE", 0, "GPIO pin where LED is connected (receive data) (default: BCM 3 physical pin 5 on the P1 header)" },
{ "refresh", 'r', "VALUE", 0, "Refresh interval (default: 20 ms)" },
{ 0 },
};
struct argp parser = {
NULL, parse_options, NULL,
"Show network activity using an LED wired to a GPIO pin.",
NULL, NULL, NULL
};
int status = EXIT_FAILURE;
FILE *netdevices = NULL;
struct timespec delay;
/* Parse the command-line */
parser.options = options;
if (argp_parse(&parser, argc, argv, ARGP_NO_ARGS, NULL, NULL))
goto out;
delay.tv_sec = o_refresh / 1000;
delay.tv_nsec = 1000000 * (o_refresh % 1000);
/* If we can't set up pigpio, then just bail */
if( gpioInitialise() < 0 ) {
fprintf( stderr, "Unable to setup the piGPIO library. STOP.");
return -1;
}
gpioSetMode( o_gpiopin_rx, PI_OUTPUT );
gpioSetMode( o_gpiopin_tx, PI_OUTPUT );
/* Open the netdevices file */
netdevices = fopen(NETDEVICES, "r");
if (!netdevices) {
perror("Could not open " NETDEVICES " for reading");
goto out;
}
/* Ensure the LED is off */
tx_led(0);
rx_led(0);
/* Save the current I/O stat values */
if (activity(netdevices) < 0)
goto out;
/* Detach from terminal? */
if (o_detach) {
pid_t child = fork();
if (child < 0) {
perror("Could not detach from terminal");
goto out;
}
if (child) {
/* I am the parent */
status = EXIT_SUCCESS;
goto out;
}
}
/* We catch these signals so we can clean up */
{
struct sigaction action;
memset(&action, 0, sizeof(action));
action.sa_handler = shutdown;
sigemptyset(&action.sa_mask);
action.sa_flags = 0; /* We block on usleep; don't use SA_RESTART */
sigaction(SIGHUP, &action, NULL);
sigaction(SIGINT, &action, NULL);
sigaction(SIGTERM, &action, NULL);
}
/* Loop until signal received */
while (running) {
if (nanosleep(&delay, NULL) < 0)
break;
if( activity(netdevices) < 0 )
break;
}
/* Ensure the LED is off */
tx_led(0);
rx_led(0);
status = EXIT_SUCCESS;
out:
/* Halt any library functions */
gpioTerminate();
if (line) free(line);
if (netdevices) fclose(netdevices);
return status;
}