socket_client.c

/* Pi-hole: A black hole for Internet advertisements
*  (c) 2017 Pi-hole, LLC (https://pi-hole.net)
*  Network-wide ad blocking via your own hardware.
*
*  FTL Engine
*  Unix socket connection test program
*
*  This file is copyright under the latest version of the EUPL.
*  Please see LICENSE file for your rights under this license. */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#define BUF 1024

int main (int argc, char **argv) {
	int socketfd;
	char *buffer = malloc (BUF);
	struct sockaddr_un address;
	ssize_t size;
	int ret;

	// Create socket
	socketfd = socket(PF_LOCAL, SOCK_STREAM, 0);
	if(socketfd <= 0)
	{
		printf("Error creating socket!\n");
		exit(EXIT_FAILURE);
	}
	printf("Socket created\n");

	// Set socket family to local socket (not an Internet socket)
	address.sun_family = AF_LOCAL;

	char *command = ">stats";
	strcpy(address.sun_path,"/var/run/pihole/FTL.sock");

	int i;
	for(i = 1; i < argc; i++) {
		// Get command
		if(strstr(argv[i], ">") == argv[i]) {
			command = argv[i];
			continue;
		}

		// Set socket file location (respect special location on the CI system Travis)
		if(strcmp(argv[i], "travis") == 0)
			strcpy(address.sun_path,"pihole-FTL.sock");
	}

	// Connect to the socket provided by pihole-FTL
	ret = connect(socketfd, (struct sockaddr *) &address, sizeof (address));
	if (ret != 0)
	{
		printf("Error establishing connection! %s\n", strerror(errno));
		exit(EXIT_FAILURE);
	}
	printf("Connection established\n");

	// As an example, we query the current statistics from FTL through the socket here
	sprintf(buffer, command);
	send(socketfd, buffer, strlen (buffer), 0);

	// Try to receive data until either recv() fails or we see "--EOM--"
	while((size = recv(socketfd, buffer, BUF-1, 0)) > -1)
	{
		// Print received data to stdout
		for(i = 0; i < size; ++i) {
			printf("%02x ", (unsigned char) buffer[i]);
		}

		// Exit on End Of Message
		if((unsigned char) buffer[size-1] == 0xc1)
			break;
	}

	printf("\n");

	// Close Unix socket connection
	close(socketfd);
	return EXIT_SUCCESS;
}