static int __init br_init(void)
{
int err;
br_stp_sap = llc_sap_open(LLC_SAP_BSPAN, br_stp_rcv);
if (!br_stp_sap) {
printk(KERN_ERR "bridge: can't register sap for STP\n");
return -EADDRINUSE;
}
br_fdb_init();
err = br_netfilter_init();
if (err)
goto err_out1;
err = register_netdevice_notifier(&br_device_notifier);
if (err)
goto err_out2;
br_netlink_init();
brioctl_set(br_ioctl_deviceless_stub);
br_handle_frame_hook = br_handle_frame;
br_fdb_get_hook = br_fdb_get;
br_fdb_put_hook = br_fdb_put;
return 0;
err_out2:
br_netfilter_fini();
err_out1:
llc_sap_put(br_stp_sap);
return err;
}
/**
* llc_ui_autobind - Bind a socket to a specific address.
* @sk: Socket to bind an address to.
* @addr: Address the user wants the socket bound to.
*
* Bind a socket to a specific address. For llc a user is able to bind to
* a specific sap only or mac + sap. If the user only specifies a sap and
* a null dmac (all zeros) the user is attempting to bind to an entire
* sap. This will stop anyone else on the local system from using that
* sap. If someone else has a mac + sap open the bind to null + sap will
* fail.
* If the user desires to bind to a specific mac + sap, it is possible to
* have multiple sap connections via multiple macs.
* Bind and autobind for that matter must enforce the correct sap usage
* otherwise all hell will break loose.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
{
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap;
int rc = -EINVAL;
if (!sock_flag(sk, SOCK_ZAPPED))
goto out;
rc = -ENODEV;
llc->dev = dev_getfirstbyhwtype(addr->sllc_arphrd);
if (!llc->dev)
goto out;
rc = -EUSERS;
llc->laddr.lsap = llc_ui_autoport();
if (!llc->laddr.lsap)
goto out;
rc = -EBUSY; /* some other network layer is using the sap */
sap = llc_sap_open(llc->laddr.lsap, NULL);
if (!sap)
goto out;
memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
memcpy(&llc->addr, addr, sizeof(llc->addr));
/* assign new connection to its SAP */
llc_sap_add_socket(sap, sk);
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out:
return rc;
}
/**
* llc_ui_bind - bind a socket to a specific address.
* @sock: Socket to bind an address to.
* @uaddr: Address the user wants the socket bound to.
* @addrlen: Length of the uaddr structure.
*
* Bind a socket to a specific address. For llc a user is able to bind to
* a specific sap only or mac + sap. If the user only specifies a sap and
* a null dmac (all zeros) the user is attempting to bind to an entire
* sap. This will stop anyone else on the local system from using that
* sap. If someone else has a mac + sap open the bind to null + sap will
* fail.
* If the user desires to bind to a specific mac + sap, it is possible to
* have multiple sap connections via multiple macs.
* Bind and autobind for that matter must enforce the correct sap usage
* otherwise all hell will break loose.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
{
struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap;
int rc = -EINVAL;
dprintk("%s: binding %02X\n", __FUNCTION__, addr->sllc_sap);
if (!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))
goto out;
rc = -EAFNOSUPPORT;
if (addr->sllc_family != AF_LLC)
goto out;
if (!addr->sllc_sap) {
rc = -EUSERS;
addr->sllc_sap = llc_ui_autoport();
if (!addr->sllc_sap)
goto out;
}
sap = llc_sap_find(addr->sllc_sap);
if (!sap) {
sap = llc_sap_open(addr->sllc_sap, NULL);
rc = -EBUSY; /* some other network layer is using the sap */
if (!sap)
goto out;
} else {
struct llc_addr laddr, daddr;
struct sock *ask;
memset(&laddr, 0, sizeof(laddr));
memset(&daddr, 0, sizeof(daddr));
/*
* FIXME: check if the the address is multicast,
* only SOCK_DGRAM can do this.
*/
memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
laddr.lsap = addr->sllc_sap;
rc = -EADDRINUSE; /* mac + sap clash. */
ask = llc_lookup_established(sap, &daddr, &laddr);
if (ask) {
sock_put(ask);
goto out;
}
}
llc->laddr.lsap = addr->sllc_sap;
memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
memcpy(&llc->addr, addr, sizeof(llc->addr));
/* assign new connection to its SAP */
llc_sap_add_socket(sap, sk);
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out:
return rc;
}
static int __init br_init(void)
{
int err;
br_stp_sap = llc_sap_open(LLC_SAP_BSPAN, br_stp_rcv);
if (!br_stp_sap) {
printk(KERN_ERR "bridge: can't register sap for STP\n");
return -EADDRINUSE;
}
//网桥数据库初始化，分配slab缓冲区
err = br_fdb_init();
if (err)
goto err_out;
//netfilter钩子初始
err = br_netfilter_init();
if (err)
goto err_out1;
////在netdev_chain通知链表上注册
err = register_netdevice_notifier(&br_device_notifier);
if (err)
goto err_out2;
err = br_netlink_init();
if (err)
goto err_out3;
//设置ioctl钩子函数:br_ioctl_hook
//通过brctl addbr br0命令建立网桥，此处用户空间调用的brctl命令最终对应到内核中的br_ioctl_deviceless_stub处理函数
brioctl_set(br_ioctl_deviceless_stub);
//设置报文处理钩子函数
br_handle_frame_hook = br_handle_frame;
//网桥数据库处理钩子
br_fdb_get_hook = br_fdb_get;
br_fdb_put_hook = br_fdb_put;
return 0;
err_out3:
unregister_netdevice_notifier(&br_device_notifier);
err_out2:
br_netfilter_fini();
err_out1:
br_fdb_fini();
err_out:
llc_sap_put(br_stp_sap);
return err;
}
struct datalink_proto *register_8022_client(unsigned char type,
int (*func)(struct sk_buff *skb,
struct net_device *dev,
struct packet_type *pt))
{
struct datalink_proto *proto;
proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
if (proto) {
proto->type[0] = type;
proto->header_length = 3;
proto->request = p8022_request;
proto->sap = llc_sap_open(type, func);
if (!proto->sap) {
kfree(proto);
proto = NULL;
}
}
return proto;
}
int stp_proto_register(const struct stp_proto *proto)
{
int err = 0;
mutex_lock(&stp_proto_mutex);
if (sap_registered++ == 0) {
sap = llc_sap_open(LLC_SAP_BSPAN, stp_pdu_rcv);
if (!sap) {
err = -ENOMEM;
goto out;
}
}
if (is_zero_ether_addr(proto->group_address))
rcu_assign_pointer(stp_proto, proto);
else
rcu_assign_pointer(garp_protos[proto->group_address[5] -
GARP_ADDR_MIN], proto);
out:
mutex_unlock(&stp_proto_mutex);
return err;
}
