/**
* llc_sap_state_process - sends event to SAP state machine
* @sap: sap to use
* @skb: pointer to occurred event
*
* After executing actions of the event, upper layer will be indicated
* if needed(on receiving an UI frame). sk can be null for the
* datalink_proto case.
*/
static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
/*
* We have to hold the skb, because llc_sap_next_state
* will kfree it in the sending path and we need to
* look at the skb->cb, where we encode llc_sap_state_ev.
*/
skb_get(skb);
ev->ind_cfm_flag = 0;
llc_sap_next_state(sap, skb);
if (ev->ind_cfm_flag == LLC_IND) {
if (skb->sk->sk_state == TCP_LISTEN)
kfree_skb(skb);
else {
llc_save_primitive(skb->sk, skb, ev->prim);
/* queue skb to the user. */
if (sock_queue_rcv_skb(skb->sk, skb))
kfree_skb(skb);
}
}
kfree_skb(skb);
}
int llc_sap_ev_activation_req(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
return ev->type == LLC_SAP_EV_TYPE_SIMPLE &&
ev->prim_type == LLC_SAP_EV_ACTIVATION_REQ ? 0 : 1;
}
int llc_sap_ev_test_req(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
return ev->type == LLC_SAP_EV_TYPE_PRIM &&
ev->prim == LLC_TEST_PRIM &&
ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;
}
int llc_sap_ev_rx_test_r(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
return ev->type == LLC_SAP_EV_TYPE_PDU && LLC_PDU_IS_RSP(pdu) &&
LLC_PDU_TYPE_IS_U(pdu) &&
LLC_U_PDU_RSP(pdu) == LLC_1_PDU_CMD_TEST ? 0 : 1;
}
/**
* llc_sap_rcv - sends received pdus to the sap state machine
* @sap: current sap component structure.
* @skb: received frame.
*
* Sends received pdus to the sap state machine.
*/
static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb,
struct sock *sk)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
ev->type = LLC_SAP_EV_TYPE_PDU;
ev->reason = 0;
skb->sk = sk;
llc_sap_state_process(sap, skb);
}
int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
int rc;
llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
ev->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_test_cmd(skb);
rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
if (likely(!rc))
rc = dev_queue_xmit(skb);
return rc;
}
/**
* llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
* @sap: pointer to SAP
* @skb: received pdu
*/
void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
switch (LLC_U_PDU_RSP(pdu)) {
case LLC_1_PDU_CMD_TEST:
ev->prim = LLC_TEST_PRIM; break;
case LLC_1_PDU_CMD_XID:
ev->prim = LLC_XID_PRIM; break;
case LLC_1_PDU_CMD_UI:
ev->prim = LLC_DATAUNIT_PRIM; break;
}
ev->ind_cfm_flag = LLC_IND;
}
/**
* llc_build_and_send_xid_pkt - XID interface for upper layers
* @sap: sap to use
* @skb: packet to send
* @dmac: destination mac address
* @dsap: destination sap
*
* This function is called when upper layer wants to send a XID pdu.
* Returns 0 for success, 1 otherwise.
*/
void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb,
u8 *dmac, u8 dsap)
{
struct llc_sap_state_ev *ev = llc_sap_ev(skb);
ev->saddr.lsap = sap->laddr.lsap;
ev->daddr.lsap = dsap;
memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
ev->type = LLC_SAP_EV_TYPE_PRIM;
ev->prim = LLC_XID_PRIM;
ev->prim_type = LLC_PRIM_TYPE_REQ;
llc_sap_state_process(sap, skb);
}
