/**
* llc_establish_connection - Called by upper layer to establish a conn
* @sk: connection
* @lmac: local mac address
* @dmac: destination mac address
* @dsap: destination sap
*
* Upper layer calls this to establish an LLC connection with a remote
* machine. This function packages a proper event and sends it connection
* component state machine. Success or failure of connection
* establishment will inform to upper layer via calling it's confirm
* function and passing proper information.
*/
int llc_establish_connection(struct sock *sk, u8 *lmac, u8 *dmac, u8 dsap)
{
int rc = -EISCONN;
struct llc_addr laddr, daddr;
struct sk_buff *skb;
struct llc_opt *llc = llc_sk(sk);
struct sock *existing;
laddr.lsap = llc->sap->laddr.lsap;
daddr.lsap = dsap;
memcpy(daddr.mac, dmac, sizeof(daddr.mac));
memcpy(laddr.mac, lmac, sizeof(laddr.mac));
existing = llc_lookup_established(llc->sap, &daddr, &laddr);
if (existing) {
if (existing->sk_state == TCP_ESTABLISHED) {
sk = existing;
goto out_put;
} else
sock_put(existing);
}
sock_hold(sk);
rc = -ENOMEM;
skb = alloc_skb(0, GFP_ATOMIC);
if (skb) {
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->type = LLC_CONN_EV_TYPE_PRIM;
ev->prim = LLC_CONN_PRIM;
ev->prim_type = LLC_PRIM_TYPE_REQ;
rc = llc_conn_state_process(sk, skb);
}
out_put:
sock_put(sk);
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;
}
