int llc_conn_ac_resend_i_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 nr = LLC_I_GET_NR(pdu);
llc_conn_resend_i_pdu_as_rsp(sk, nr, 1);
return 0;
}
int llc_conn_ev_rx_i_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return llc_conn_space(sk, skb) &&
LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
}
int llc_conn_ac_resend_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 nr = LLC_I_GET_NR(pdu);
llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
return 0;
}
int llc_conn_ev_rx_rnr_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
LLC_S_PF_IS_1(pdu) &&
LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_RNR ? 0 : 1;
}
int llc_conn_ev_rx_rnr_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
LLC_S_PF_IS_0(pdu) &&
LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RNR ? 0 : 1;
}
int llc_conn_ev_rx_rej_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)
{
const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
LLC_S_PF_IS_0(pdu) &&
LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;
}
int llc_conn_ev_rx_rej_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
{
const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&
LLC_S_PF_IS_1(pdu) &&
LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_REJ ? 0 : 1;
}
int llc_conn_ev_rx_i_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
return llc_conn_space(sk, skb) &&
LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
LLC_I_PF_IS_1(pdu) &&
LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;
}
int llc_conn_ac_upd_vs(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 nr = PDU_SUPV_GET_Nr(pdu);
if (llc_circular_between(llc_sk(sk)->vS, nr, llc_sk(sk)->X))
llc_conn_ac_set_vs_nr(sk, skb);
return 0;
}
int llc_conn_ev_rx_i_rsp_fbit_set_x_unexpd_ns(struct sock *sk,
struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 vr = llc_sk(sk)->vR;
u8 ns = LLC_I_GET_NS(pdu);
return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) && ns != vr &&
!llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
}
void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
pdu->ctrl_1 = LLC_PDU_TYPE_I;
pdu->ctrl_2 = 0;
pdu->ctrl_2 |= (p_bit & LLC_I_PF_BIT_MASK);
pdu->ctrl_1 |= (ns << 1) & 0xFE;
pdu->ctrl_2 |= (nr << 1) & 0xFE;
}
void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
pdu->ctrl_1 = LLC_PDU_TYPE_S;
pdu->ctrl_1 |= LLC_2_PDU_CMD_RR;
pdu->ctrl_2 = p_bit & LLC_S_PF_BIT_MASK;
pdu->ctrl_1 &= 0x0F;
pdu->ctrl_2 |= (nr << 1) & 0xFE;
}
int llc_conn_ac_resend_i_cmd_p_set_1_or_send_rr(struct sock *sk,
struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 nr = LLC_I_GET_NR(pdu);
int rc = llc_conn_ac_send_rr_cmd_p_set_1(sk, skb);
if (!rc)
llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
return rc;
}
void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
pdu->ctrl_1 = LLC_PDU_TYPE_S;
pdu->ctrl_1 |= LLC_2_PDU_RSP_RNR;
pdu->ctrl_2 = 0;
pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK;
pdu->ctrl_1 &= 0x0F;
pdu->ctrl_2 |= (nr << 1) & 0xFE;
}
int llc_conn_ac_clear_remote_busy_if_f_eq_1(struct sock *sk,
struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_IS_RSP(pdu) &&
LLC_PDU_TYPE_IS_I(pdu) &&
LLC_I_PF_IS_1(pdu) && llc_sk(sk)->ack_pf)
llc_conn_ac_clear_remote_busy(sk, skb);
return 0;
}
int llc_conn_ev_rx_i_cmd_pbit_set_1_unexpd_ns(struct sock *sk,
struct sk_buff *skb)
{
const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
const u8 vr = llc_sk(sk)->vR;
const u8 ns = LLC_I_GET_NS(pdu);
return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&
LLC_I_PF_IS_1(pdu) && ns != vr &&
!llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
}
/**
* llc_rcv - 802.2 entry point from net lower layers
* @skb: received pdu
* @dev: device that receive pdu
* @pt: packet type
*
* When the system receives a 802.2 frame this function is called. It
* checks SAP and connection of received pdu and passes frame to
* llc_{station,sap,conn}_rcv for sending to proper state machine. If
* the frame is related to a busy connection (a connection is sending
* data now), it queues this frame in the connection's backlog.
*/
int llc_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt)
{
struct llc_sap *sap;
struct llc_pdu_sn *pdu;
int dest;
/*
* When the interface is in promisc. mode, drop all the crap that it
* receives, do not try to analyse it.
*/
if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
dprintk("%s: PACKET_OTHERHOST\n", __FUNCTION__);
goto drop;
}
skb = skb_share_check(skb, GFP_ATOMIC);
if (unlikely(!skb))
goto out;
if (unlikely(!llc_fixup_skb(skb)))
goto drop;
pdu = llc_pdu_sn_hdr(skb);
if (unlikely(!pdu->dsap)) /* NULL DSAP, refer to station */
goto handle_station;
sap = llc_sap_find(pdu->dsap);
if (unlikely(!sap)) {/* unknown SAP */
dprintk("%s: llc_sap_find(%02X) failed!\n", __FUNCTION__,
pdu->dsap);
goto drop;
}
/*
* First the upper layer protocols that don't need the full
* LLC functionality
*/
if (sap->rcv_func) {
sap->rcv_func(skb, dev, pt);
goto out;
}
dest = llc_pdu_type(skb);
if (unlikely(!dest || !llc_type_handlers[dest - 1]))
goto drop;
llc_type_handlers[dest - 1](sap, skb);
out:
return 0;
drop:
kfree_skb(skb);
goto out;
handle_station:
if (!llc_station_handler)
goto drop;
llc_station_handler(skb);
goto out;
}
int llc_conn_ev_rx_i_rsp_fbit_set_x_inval_ns(struct sock *sk,
struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 vr = llc_sk(sk)->vR;
u8 ns = LLC_I_GET_NS(pdu);
u16 rc = LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) && ns != vr &&
llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;
if (!rc)
dprintk("%s: matched, state=%d, ns=%d, vr=%d\n",
__FUNCTION__, llc_sk(sk)->state, ns, vr);
return rc;
}
/**
* llc_util_nr_inside_tx_window - check if sequence number is in tx window
* @sk: current connection.
* @nr: N(R) of received PDU.
*
* This routine checks if N(R) of received PDU is in range of transmit
* window; on the other hand checks if received PDU acknowledges some
* outstanding PDUs that are in transmit window. Returns 0 for success, 1
* otherwise.
*/
static u16 llc_util_nr_inside_tx_window(struct sock *sk, u8 nr)
{
u8 nr1, nr2;
struct sk_buff *skb;
struct llc_pdu_sn *pdu;
struct llc_opt *llc = llc_sk(sk);
int rc = 0;
if (llc->dev->flags & IFF_LOOPBACK)
goto out;
rc = 1;
if (!skb_queue_len(&llc->pdu_unack_q))
goto out;
skb = skb_peek(&llc->pdu_unack_q);
pdu = llc_pdu_sn_hdr(skb);
nr1 = LLC_I_GET_NS(pdu);
skb = skb_peek_tail(&llc->pdu_unack_q);
pdu = llc_pdu_sn_hdr(skb);
nr2 = LLC_I_GET_NS(pdu);
rc = !llc_circular_between(nr1, nr, (nr2 + 1) % LLC_2_SEQ_NBR_MODULO);
out:
return rc;
}
int llc_conn_ev_rx_xxx_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb)
{
u16 rc = 1;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_IS_CMD(pdu)) {
if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) {
if (LLC_I_PF_IS_1(pdu))
rc = 0;
} else if (LLC_PDU_TYPE_IS_U(pdu) && LLC_U_PF_IS_1(pdu))
rc = 0;
}
return rc;
}
int llc_conn_ac_upd_p_flag(struct sock *sk, struct sk_buff *skb)
{
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_IS_RSP(pdu)) {
u8 f_bit;
llc_pdu_decode_pf_bit(skb, &f_bit);
if (f_bit) {
llc_conn_set_p_flag(sk, 0);
llc_conn_ac_stop_p_timer(sk, skb);
}
}
return 0;
}
int llc_conn_ac_clear_remote_busy(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (llc->remote_busy_flag) {
u8 nr;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
llc->remote_busy_flag = 0;
del_timer(&llc->busy_state_timer.timer);
nr = LLC_I_GET_NR(pdu);
llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
}
return 0;
}
int llc_conn_ev_rx_zzz_cmd_pbit_set_x_inval_nr(struct sock *sk,
struct sk_buff *skb)
{
u16 rc = 1;
const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
const u8 vs = llc_sk(sk)->vS;
const u8 nr = LLC_I_GET_NR(pdu);
if (LLC_PDU_IS_CMD(pdu) &&
(LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) &&
nr != vs && llc_util_nr_inside_tx_window(sk, nr)) {
dprintk("%s: matched, state=%d, vs=%d, nr=%d\n",
__func__, llc_sk(sk)->state, vs, nr);
rc = 0;
}
return rc;
}
int llc_conn_ev_rx_zzz_rsp_fbit_set_x_inval_nr(struct sock *sk,
struct sk_buff *skb)
{
u16 rc = 1;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
u8 vs = llc_sk(sk)->vS;
u8 nr = LLC_I_GET_NR(pdu);
if (LLC_PDU_IS_RSP(pdu) &&
(LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) &&
nr != vs && llc_util_nr_inside_tx_window(sk, nr)) {
rc = 0;
dprintk("%s: matched, state=%d, vs=%d, nr=%d\n",
__FUNCTION__, llc_sk(sk)->state, vs, nr);
}
return rc;
}
void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value)
{
u8 pdu_type;
struct llc_pdu_sn *pdu;
llc_pdu_decode_pdu_type(skb, &pdu_type);
pdu = llc_pdu_sn_hdr(skb);
switch (pdu_type) {
case LLC_PDU_TYPE_I:
case LLC_PDU_TYPE_S:
pdu->ctrl_2 = (pdu->ctrl_2 & 0xFE) | bit_value;
break;
case LLC_PDU_TYPE_U:
pdu->ctrl_1 |= (pdu->ctrl_1 & 0xEF) | (bit_value << 4);
break;
}
}
void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit)
{
u8 pdu_type;
struct llc_pdu_sn *pdu;
llc_pdu_decode_pdu_type(skb, &pdu_type);
pdu = llc_pdu_sn_hdr(skb);
switch (pdu_type) {
case LLC_PDU_TYPE_I:
case LLC_PDU_TYPE_S:
*pf_bit = pdu->ctrl_2 & LLC_S_PF_BIT_MASK;
break;
case LLC_PDU_TYPE_U:
*pf_bit = (pdu->ctrl_1 & LLC_U_PF_BIT_MASK) >> 4;
break;
}
}
/**
* llc_conn_send_pdus - Sends queued PDUs
* @sk: active connection
*
* Sends queued pdus to MAC layer for transmission.
*/
static void llc_conn_send_pdus(struct sock *sk)
{
struct sk_buff *skb;
while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) {
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_TYPE_IS_I(pdu) &&
!(skb->dev->flags & IFF_LOOPBACK)) {
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb);
if (!skb2)
break;
skb = skb2;
}
dev_queue_xmit(skb);
}
}
int llc_conn_ev_rx_xxx_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb)
{
u16 rc = 1;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_IS_CMD(pdu)) {
if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) {
if (LLC_I_PF_IS_0(pdu))
rc = 0;
} else if (LLC_PDU_TYPE_IS_U(pdu))
switch (LLC_U_PDU_CMD(pdu)) {
case LLC_2_PDU_CMD_SABME:
case LLC_2_PDU_CMD_DISC:
if (LLC_U_PF_IS_0(pdu))
rc = 0;
break;
}
}
return rc;
}
int llc_conn_ev_rx_xxx_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb)
{
u16 rc = 1;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
if (LLC_PDU_IS_RSP(pdu)) {
if (LLC_PDU_TYPE_IS_I(pdu) || LLC_PDU_TYPE_IS_S(pdu)) {
if (LLC_I_PF_IS_1(pdu))
rc = 0;
} else if (LLC_PDU_TYPE_IS_U(pdu))
switch (LLC_U_PDU_RSP(pdu)) {
case LLC_2_PDU_RSP_UA:
case LLC_2_PDU_RSP_DM:
case LLC_2_PDU_RSP_FRMR:
if (LLC_U_PF_IS_1(pdu))
rc = 0;
break;
}
}
return rc;
}
/**
* llc_rcv - 802.2 entry point from net lower layers
* @skb: received pdu
* @dev: device that receive pdu
* @pt: packet type
*
* When the system receives a 802.2 frame this function is called. It
* checks SAP and connection of received pdu and passes frame to
* llc_{station,sap,conn}_rcv for sending to proper state machine. If
* the frame is related to a busy connection (a connection is sending
* data now), it queues this frame in the connection's backlog.
*/
int llc_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct llc_sap *sap;
struct llc_pdu_sn *pdu;
int dest;
int (*rcv)(struct sk_buff *, struct net_device *,
struct packet_type *, struct net_device *);
void (*sta_handler)(struct sk_buff *skb);
void (*sap_handler)(struct llc_sap *sap, struct sk_buff *skb);
if (!net_eq(dev_net(dev), &init_net))
goto drop;
/*
* When the interface is in promisc. mode, drop all the crap that it
* receives, do not try to analyse it.
*/
if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
dprintk("%s: PACKET_OTHERHOST\n", __func__);
goto drop;
}
skb = skb_share_check(skb, GFP_ATOMIC);
if (unlikely(!skb))
goto out;
if (unlikely(!llc_fixup_skb(skb)))
goto drop;
pdu = llc_pdu_sn_hdr(skb);
if (unlikely(!pdu->dsap)) /* NULL DSAP, refer to station */
goto handle_station;
sap = llc_sap_find(pdu->dsap);
if (unlikely(!sap)) {/* unknown SAP */
dprintk("%s: llc_sap_find(%02X) failed!\n", __func__,
pdu->dsap);
goto drop;
}
/*
* First the upper layer protocols that don't need the full
* LLC functionality
*/
rcv = rcu_dereference(sap->rcv_func);
dest = llc_pdu_type(skb);
sap_handler = dest ? ACCESS_ONCE(llc_type_handlers[dest - 1]) : NULL;
if (unlikely(!sap_handler)) {
if (rcv)
rcv(skb, dev, pt, orig_dev);
else
kfree_skb(skb);
} else {
if (rcv) {
struct sk_buff *cskb = skb_clone(skb, GFP_ATOMIC);
if (cskb)
rcv(cskb, dev, pt, orig_dev);
}
sap_handler(sap, skb);
}
llc_sap_put(sap);
out:
return 0;
drop:
kfree_skb(skb);
goto out;
handle_station:
sta_handler = ACCESS_ONCE(llc_station_handler);
if (!sta_handler)
goto drop;
sta_handler(skb);
goto out;
}
