Linux 内核 net_proto_family

static const struct net_proto_family inet_family_ops = { 

.family = PF_INET, 

.create = inet_create, 

.owner 
  = THIS_MODULE, 
};
(void)sock_register(&inet_family_ops);
 /**
  * sock_register - add a socket protocol handler
  * @ops: description of protocol
  *
  * This function is called by a protocol handler that wants to
  * advertise its address family, and have it linked into the
  * socket interface. The value ops->family corresponds to the
  * socket system call protocol family.
  */
 int sock_register(const struct net_proto_family *ops)
 {
int err;


if (ops->family >= NPROTO) {
pr_crit("protocol %d >= NPROTO(%d)\n", ops->family, NPROTO);
return -ENOBUFS;
}


spin_lock(&net_family_lock);
if (rcu_dereference_protected(net_families[ops->family],
     lockdep_is_held(&net_family_lock)))
err = -EEXIST;
else {
rcu_assign_pointer(net_families[ops->family], ops);
err = 0;
}
spin_unlock(&net_family_lock);


pr_info("NET: Registered protocol family %d\n", ops->family);
return err;
 }
void sock_unregister(int family)
 {
BUG_ON(family < 0 || family >= NPROTO);


spin_lock(&net_family_lock);
RCU_INIT_POINTER(net_families[family], NULL);
spin_unlock(&net_family_lock);


synchronize_rcu();


pr_info("NET: Unregistered protocol family %d\n", family);
 }
 EXPORT_SYMBOL(sock_unregister);
static const struct net_proto_family inet6_family_ops = {
.family = PF_INET6,
.create = inet6_create,
.owner  = THIS_MODULE,
 };
static const struct net_proto_family unix_family_ops = {
.family = PF_UNIX,
.create = unix_create,
.owner  = THIS_MODULE,
 };
static const struct net_proto_family ipx_family_ops = {
.family  = PF_IPX,
.create  = ipx_create,
.owner  = THIS_MODULE,
 };
static const struct net_proto_family packet_family_ops = {
.family =  PF_PACKET,
.create =  packet_create,
.owner  = THIS_MODULE,
 };
static const struct net_proto_family netlink_family_ops = {
.family = PF_NETLINK,
.create = netlink_create,
.owner  = THIS_MODULE, /* for consistency 8) */
 };
static struct net_proto_family nfc_sock_family_ops = {
.owner  = THIS_MODULE,
.family = PF_NFC,
.create = nfc_sock_create,
 };
static const struct net_proto_family bnep_sock_family_ops = {
.family = PF_BLUETOOTH,
.owner  = THIS_MODULE,
.create = bnep_sock_create
 };static const struct net_proto_family mISDN_sock_family_ops = {
.owner  = THIS_MODULE,
.family = PF_ISDN,
.create = mISDN_sock_create,
 };