net.c

#include "net.h"

char ip[SMAX];

char *host_to_ip(char *hostname, char *ip) { // 查出 host 對應的 ip
	struct hostent *host = gethostbyname(hostname);
	/*
	char **pp;
	printf("hostname=%s\n", host->h_name);
	for (pp=host->h_aliases; *pp != NULL; pp++)
		printf("  alias:%s\n", *pp);
	for (pp=host->h_addr_list; *pp != NULL; pp++)
		printf("  address:%s\n", inet_ntop(host->h_addrtype, *pp, ip, SMAX));
	printf("  ip=%s\n", ip);
	*/
	inet_ntop(host->h_addrtype, host->h_addr_list[0], ip, SMAX); // 取第一個 IP
	return ip;
}

int net_init(net_t *net, int protocol, int side, int port, char *host) {
	memset(net, 0, sizeof(net_t));
	net->protocol = protocol;
	net->side = side;
	net->port = port;
	net->serv_ip = (side==CLIENT) ? host_to_ip(host, ip) : "127.0.0.1";
	int socketType = (protocol == TCP) ? SOCK_STREAM : SOCK_DGRAM;
	net->sock_fd = socket(AF_INET, socketType, 0);
  assert(net->sock_fd >= 0);
	net->serv_addr.sin_family = AF_INET;
	net->serv_addr.sin_addr.s_addr = (side == SERVER) ? htonl(INADDR_ANY) : inet_addr(net->serv_ip);
	net->serv_addr.sin_port = htons(net->port);
  return 0;
}

int net_connect(net_t *net) {
	int r = connect(net->sock_fd, (struct sockaddr *)&net->serv_addr, sizeof(net->serv_addr));
	// assert(r>=0);
	return r;
}

int net_bind(net_t *net) {
	int r = bind(net->sock_fd, (struct sockaddr*)&net->serv_addr, sizeof(net->serv_addr));
	assert(r>=0);
	return r;
}

int net_listen(net_t *net) {
	int r = listen(net->sock_fd, 10); // 最多十個同時連線
	assert(r>=0);
	return r;
}

int net_accept(net_t *net) {
	int r = accept(net->sock_fd, (struct sockaddr*)NULL, NULL);
	assert(r>=0);
	return r;
}

int net_close(net_t *net) {
	shutdown(net->sock_fd, SHUT_WR);
	close(net->sock_fd);
	return 0;
}