yasnd/daemon/yasnd-sock.c

#include <stdio.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <linux/un.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>

#include "yasnd-log.h"
#include "yasnd-lpt.h"

const char sock_path[]="/var/run/yasnd.sock";
pthread_t server_thread_handle; // server socket thread handle
int socket_fd; // server socket descriptor

#define STATUS_OK (void*)0
#define STATUS_ERROR (void*)1

void* connection_handler(void* param)
{
	// Get connection descriptor
	int connection_fd=*(int*)param;

	// Buffer for client command and command's actual length
	char buffer[256];
	int nbytes;

	// Token for string splitting
	char* token;

	// Status of command parsing (default is OK)
	void* thread_status = STATUS_OK;

	while ( (nbytes = read(connection_fd, buffer, 256)) != -1 )
	{
		buffer[nbytes] = 0;

		token = strtok(buffer, " ");
		if (token == NULL)
		{
			// empty input from client
			thread_status = STATUS_ERROR;
			break;
		}

		// Exit function
		if (strncmp(token, "exit", 4) == 0)
		{
			// just break loop and thus close client connection
			break;
		}
		// Reset function
		if (strncmp(token, "reset", 5) == 0)
		{
			// Get parameter for reset call and convert it to long
			long value = strtol(strtok(NULL, " "), (char **) NULL, 10);
			// Call reset_pin function
			reset_pin((int)value);
			// continue waiting client commands
			continue;
		}
	}

	// Close client connection descriptor
	close(connection_fd);

	// Exit client thread and return apropriate status
	pthread_exit(thread_status);
}

void* server_socket(void* param)
{
	struct sockaddr_un address;
	int connection_fd;
	socklen_t address_length;

	pthread_t child_handle; // connection thread handle

	socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
	if(socket_fd < 0)
	{
		log_event("socket creation failed");
		return (void*)1;
	}

	// Remove old socket file
	unlink(sock_path);

	// start with a clean address structure
	memset(&address, 0, sizeof(struct sockaddr_un));

	address.sun_family = AF_UNIX;
	snprintf(address.sun_path, UNIX_PATH_MAX, sock_path);

	// Set umask value for new socket file
	mode_t old_umask = umask(077);

	// Create(bind) socket
	if(bind(socket_fd,
		(struct sockaddr *) &address,
		sizeof(struct sockaddr_un)) != 0)
	{
		log_event("bind() call failed");
		return (void*)1;
	}

	// Return previous umask value
	umask(old_umask);

	if(listen(socket_fd, 5) != 0)
	{
		log_event("listen() call failed");
		return (void*)1;
	}

	while((connection_fd = accept(socket_fd, (struct sockaddr *) &address, &address_length)) > -1)
	{
		if(pthread_create(&child_handle,NULL,connection_handler,&connection_fd) != 0)
		{
			log_event("Client connection thread creation failed");
		}
		else
			pthread_detach(child_handle);
	}

	return (void*)0;
}

int sock_init()
{
	if(pthread_create(&server_thread_handle,NULL,server_socket,NULL) != 0)
	{
		log_event("Server socket thread creation failed");
	}
}

void sock_close()
{
	// Terminate server socket handling thread
	pthread_cancel(server_thread_handle);
	// Close server socket
	close(socket_fd);
	// Remove unneeded socket file
	unlink(sock_path);
}