sockets.c

/* vim: set noet: */
#include <stdio.h>
#include <unistd.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>

#include "sockets.h"

int sock_connect(const char *servername, int port)
{
	struct addrinfo	*resolved_addr = NULL;
	struct addrinfo	*iterator;
	char		service[6];
	int		sockfd = -1;

	int		listenfd = 0;
	int		tmp;
	struct addrinfo hints =	{
		.ai_flags = AI_PASSIVE,
		.ai_family = AF_INET,
		.ai_socktype = SOCK_STREAM
	};

	if (sprintf(service, "%d", port) < 0)
		goto sock_connect_exit;

	/* Resolve DNS address, use sockfd as temp storage */
	sockfd = getaddrinfo(servername, service, &hints, &resolved_addr);
	if (sockfd < 0)	{
		fprintf(stderr, "%s for %s:%d\n", gai_strerror(sockfd), servername, port); goto sock_connect_exit;
	}

	/* Search through results and find the one we want */
	for (iterator = resolved_addr; iterator ; iterator = iterator->ai_next)	{
		sockfd = socket(iterator->ai_family, iterator->ai_socktype, iterator->ai_protocol);
		if (sockfd >= 0) {
			if (servername) {
				/* Client mode. Initiate connection to remote */
				if((tmp=connect(sockfd, iterator->ai_addr, iterator->ai_addrlen))) {
					fprintf(stdout, "failed connect \n");
					close(sockfd);
					sockfd = -1;
				}
			}
			else {
				/* Server mode. Set up listening socket and accept a connection */
				listenfd = sockfd;
				sockfd = -1;
				if(bind(listenfd, iterator->ai_addr, iterator->ai_addrlen))
					goto sock_connect_exit;
				listen(listenfd, 1);
				sockfd = accept(listenfd, NULL, 0);
			}
		}
	}

sock_connect_exit:

	if(listenfd) close(listenfd);

	if(resolved_addr) freeaddrinfo(resolved_addr);

	if (sockfd < 0) {
		if(servername)
			fprintf(stderr, "Couldn't connect to %s:%d\n", servername, port);
		else {
			perror("server accept");
			fprintf(stderr, "accept() failed\n");
		}
	}

	return sockfd;
}

int sock_sync_data(int sock, int xfer_size, char *local_data, char *remote_data)
{
	int	rc;
	int	read_bytes = 0;
	int	total_read_bytes = 0;

	rc = write(sock, local_data, xfer_size);
	if(rc < xfer_size)
		fprintf(stderr, "Failed writing data during sock_sync_data\n");
	else
		rc = 0;

	while(!rc && total_read_bytes < xfer_size) {
		read_bytes = read(sock, remote_data, xfer_size);
		if(read_bytes > 0)
			total_read_bytes += read_bytes;
		else
			rc = read_bytes;
	}

	return rc;
}