my_protocol.c

来自「一个基于linux的TCP/IP协议栈的实现」· C语言 代码 · 共 42 行

struct net_protocol *myinet_protos[MAX_INET_PROTOS];
static DEFINE_SPINLOCK( myinet_proto_lock );

int myinet_add_protocol(struct net_protocol *prot, unsigned char protocol)
{
	int hash, ret;

	hash = protocol & (MAX_INET_PROTOS - 1);

	spin_lock_bh(&myinet_proto_lock);
	if( myinet_protos[hash] ){
		ret = -1;
	} else {
		myinet_protos[hash] = prot;
		ret = 0;
	}
	spin_unlock_bh(&myinet_proto_lock);

	return ret;
}
 
int myinet_del_protocol(struct net_protocol *prot, unsigned char protocol)
{
	int hash, ret;

	hash = protocol & (MAX_INET_PROTOS - 1);

	spin_lock_bh( &myinet_proto_lock );
	if( myinet_protos[hash] == prot ){
		myinet_protos[hash] = NULL;
		ret = 0;
	} else {
		ret = -1;
	}
	spin_unlock_bh( &myinet_proto_lock );

	synchronize_net();

	return ret;
}