/*
* llc_c_ac.c - actions performed during connection state transition.
*
* Description:
* Functions in this module are implementation of connection component actions
* Details of actions can be found in IEEE-802.2 standard document.
* All functions have one connection and one event as input argument. All of
* them return 0 On success and 1 otherwise.
*
* Copyright (c) 1997 by Procom Technology, Inc.
* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*
* This program can be redistributed or modified under the terms of the
* GNU General Public License as published by the Free Software Foundation.
* This program is distributed without any warranty or implied warranty
* of merchantability or fitness for a particular purpose.
*
* See the GNU General Public License for more details.
*/
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <net/llc_conn.h>
#include <net/llc_sap.h>
#include <net/sock.h>
#include <net/llc_c_ev.h>
#include <net/llc_c_ac.h>
#include <net/llc_c_st.h>
#include <net/llc_pdu.h>
#include <net/llc.h>
static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb);
static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb);
static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *ev);
static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb);
static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
struct sk_buff *skb);
static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb);
#define INCORRECT 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_ac_conn_ind(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->ind_prim = LLC_CONN_PRIM;
return 0;
}
int llc_conn_ac_conn_confirm(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->cfm_prim = LLC_CONN_PRIM;
return 0;
}
static int llc_conn_ac_data_confirm(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->cfm_prim = LLC_DATA_PRIM;
return 0;
}
int llc_conn_ac_data_ind(struct sock *sk, struct sk_buff *skb)
{
llc_conn_rtn_pdu(sk, skb);
return 0;
}
int llc_conn_ac_disc_ind(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
u8 reason = 0;
int rc = 0;
if (ev->type == LLC_CONN_EV_TYPE_PDU) {
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
if (LLC_PDU_IS_RSP(pdu) &&
LLC_PDU_TYPE_IS_U(pdu) &&
LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM)
reason = LLC_DISC_REASON_RX_DM_RSP_PDU;
else if (LLC_PDU_IS_CMD(pdu) &&
LLC_PDU_TYPE_IS_U(pdu) &&
LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC)
reason = LLC_DISC_REASON_RX_DISC_CMD_PDU;
} else if (ev->type == LLC_CONN_EV_TYPE_ACK_TMR)
reason = LLC_DISC_REASON_ACK_TMR_EXP;
else
rc = -EINVAL;
if (!rc) {
ev->reason = reason;
ev->ind_prim = LLC_DISC_PRIM;
}
return rc;
}
int llc_conn_ac_disc_confirm(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->reason = ev->status;
ev->cfm_prim = LLC_DISC_PRIM;
return 0;
}
int llc_conn_ac_rst_ind(struct sock *sk, struct sk_buff *skb)
{
u8 reason = 0;
int rc = 1;
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
struct llc_sock *llc = llc_sk(sk);
switch (ev->type) {
case LLC_CONN_EV_TYPE_PDU:
if (LLC_PDU_IS_RSP(pdu) &&
LLC_PDU_TYPE_IS_U(pdu) &&
LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR) {
reason = LLC_RESET_REASON_LOCAL;
rc = 0;
} else if (LLC_PDU_IS_CMD(pdu) &&
LLC_PDU_TYPE_IS_U(pdu) &&
LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_SABME) {
reason = LLC_RESET_REASON_REMOTE;
rc = 0;
}
break;
case LLC_CONN_EV_TYPE_ACK_TMR:
case LLC_CONN_EV_TYPE_P_TMR:
case LLC_CONN_EV_TYPE_REJ_TMR:
case LLC_CONN_EV_TYPE_BUSY_TMR:
if (llc->retry_count > llc->n2) {
reason = LLC_RESET_REASON_LOCAL;
rc = 0;
}
break;
}
if (!rc) {
ev->reason = reason;
ev->ind_prim = LLC_RESET_PRIM;
}
return rc;
}
int llc_conn_ac_rst_confirm(struct sock *sk, struct sk_buff *skb)
{
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
ev->reason = 0;
ev->cfm_prim = LLC_RESET_PRIM;
return 0;
}
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_ac_stop_rej_tmr_if_data_flag_eq_2(struct sock *sk,
struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (llc->data_flag == 2)
del_timer(&llc->rej_sent_timer.timer);
return 0;
}
int llc_conn_ac_send_disc_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_disc_cmd(nskb, 1);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
llc_conn_ac_set_p_flag_1(sk, skb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_dm_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
u8 f_bit;
llc_pdu_decode_pf_bit(skb, &f_bit);
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_dm_rsp(nskb, f_bit);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_dm_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_dm_rsp(nskb, 1);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_frmr_rsp_f_set_x(struct sock *sk, struct sk_buff *skb)
{
u8 f_bit;
int rc = -ENOBUFS;
struct sk_buff *nskb;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
struct llc_sock *llc = llc_sk(sk);
llc->rx_pdu_hdr = *((u32 *)pdu);
if (LLC_PDU_IS_CMD(pdu))
llc_pdu_decode_pf_bit(skb, &f_bit);
else
f_bit = 0;
nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
sizeof(struct llc_frmr_info));
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
llc->vR, INCORRECT);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_resend_frmr_rsp_f_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
sizeof(struct llc_frmr_info));
if (nskb) {
struct llc_sap *sap = llc->sap;
struct llc_pdu_sn *pdu = (struct llc_pdu_sn *)&llc->rx_pdu_hdr;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_frmr_rsp(nskb, pdu, 0, llc->vS,
llc->vR, INCORRECT);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_resend_frmr_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
{
u8 f_bit;
int rc = -ENOBUFS;
struct sk_buff *nskb;
struct llc_sock *llc = llc_sk(sk);
llc_pdu_decode_pf_bit(skb, &f_bit);
nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U,
sizeof(struct llc_frmr_info));
if (nskb) {
struct llc_sap *sap = llc->sap;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_frmr_rsp(nskb, pdu, f_bit, llc->vS,
llc->vR, INCORRECT);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_i_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_i_cmd(skb, 1, llc->vS, llc->vR);
rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
if (likely(!rc)) {
skb_get(skb);
llc_conn_send_pdu(sk, skb);
llc_conn_ac_inc_vs_by_1(sk, skb);
}
return rc;
}
static int llc_conn_ac_send_i_cmd_p_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
if (likely(!rc)) {
skb_get(skb);
llc_conn_send_pdu(sk, skb);
llc_conn_ac_inc_vs_by_1(sk, skb);
}
return rc;
}
int llc_conn_ac_send_i_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_i_cmd(skb, 0, llc->vS, llc->vR);
rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
if (likely(!rc)) {
skb_get(skb);
llc_conn_send_pdu(sk, skb);
llc_conn_ac_inc_vs_by_1(sk, skb);
}
return 0;
}
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_ac_resend_i_xxx_x_set_0_or_send_rr(struct sock *sk,
struct sk_buff *skb)
{
u8 nr;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (likely(!rc))
llc_conn_send_pdu(sk, nskb);
else
kfree_skb(skb);
}
if (rc) {
nr = LLC_I_GET_NR(pdu);
rc = 0;
llc_conn_resend_i_pdu_as_cmd(sk, nr, 0);
}
return rc;
}
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_ac_send_rej_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_rej_cmd(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rej_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rej_rsp(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rej_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rej_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rnr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_rnr_cmd(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rnr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rnr_rsp(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_set_remote_busy(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (!llc->remote_busy_flag) {
llc->remote_busy_flag = 1;
mod_timer(&llc->busy_state_timer.timer,
jiffies + llc->busy_state_timer.expire);
}
return 0;
}
int llc_conn_ac_opt_send_rnr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rnr_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rr_cmd_p_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_rr_cmd(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rr_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
u8 f_bit = 1;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, f_bit, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_ack_rsp_f_set_1(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, 1, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_rr_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_ack_xxx_x_set_0(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, 0, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
void llc_conn_set_p_flag(struct sock *sk, u8 value)
{
int state_changed = llc_sk(sk)->p_flag && !value;
llc_sk(sk)->p_flag = value;
if (state_changed)
sk->sk_state_change(sk);
}
int llc_conn_ac_send_sabme_cmd_p_set_x(struct sock *sk, struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
u8 *dmac = llc->daddr.mac;
if (llc->dev->flags & IFF_LOOPBACK)
dmac = llc->dev->dev_addr;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_CMD);
llc_pdu_init_as_sabme_cmd(nskb, 1);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, dmac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
llc_conn_set_p_flag(sk, 1);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_send_ua_rsp_f_set_p(struct sock *sk, struct sk_buff *skb)
{
u8 f_bit;
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_U, 0);
llc_pdu_decode_pf_bit(skb, &f_bit);
if (nskb) {
struct llc_sap *sap = llc->sap;
nskb->dev = llc->dev;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_ua_rsp(nskb, f_bit);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
int llc_conn_ac_set_s_flag_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->s_flag = 0;
return 0;
}
int llc_conn_ac_set_s_flag_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->s_flag = 1;
return 0;
}
int llc_conn_ac_start_p_timer(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
llc_conn_set_p_flag(sk, 1);
mod_timer(&llc->pf_cycle_timer.timer,
jiffies + llc->pf_cycle_timer.expire);
return 0;
}
/**
* llc_conn_ac_send_ack_if_needed - check if ack is needed
* @sk: current connection structure
* @skb: current event
*
* Checks number of received PDUs which have not been acknowledged, yet,
* If number of them reaches to "npta"(Number of PDUs To Acknowledge) then
* sends an RR response as acknowledgement for them. Returns 0 for
* success, 1 otherwise.
*/
int llc_conn_ac_send_ack_if_needed(struct sock *sk, struct sk_buff *skb)
{
u8 pf_bit;
struct llc_sock *llc = llc_sk(sk);
llc_pdu_decode_pf_bit(skb, &pf_bit);
llc->ack_pf |= pf_bit & 1;
if (!llc->ack_must_be_send) {
llc->first_pdu_Ns = llc->vR;
llc->ack_must_be_send = 1;
llc->ack_pf = pf_bit & 1;
}
if (((llc->vR - llc->first_pdu_Ns + 1 + LLC_2_SEQ_NBR_MODULO)
% LLC_2_SEQ_NBR_MODULO) >= llc->npta) {
llc_conn_ac_send_rr_rsp_f_set_ackpf(sk, skb);
llc->ack_must_be_send = 0;
llc->ack_pf = 0;
llc_conn_ac_inc_npta_value(sk, skb);
}
return 0;
}
/**
* llc_conn_ac_rst_sendack_flag - resets ack_must_be_send flag
* @sk: current connection structure
* @skb: current event
*
* This action resets ack_must_be_send flag of given connection, this flag
* indicates if there is any PDU which has not been acknowledged yet.
* Returns 0 for success, 1 otherwise.
*/
int llc_conn_ac_rst_sendack_flag(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->ack_must_be_send = llc_sk(sk)->ack_pf = 0;
return 0;
}
/**
* llc_conn_ac_send_i_rsp_f_set_ackpf - acknowledge received PDUs
* @sk: current connection structure
* @skb: current event
*
* Sends an I response PDU with f-bit set to ack_pf flag as acknowledge to
* all received PDUs which have not been acknowledged, yet. ack_pf flag is
* set to one if one PDU with p-bit set to one is received. Returns 0 for
* success, 1 otherwise.
*/
static int llc_conn_ac_send_i_rsp_f_set_ackpf(struct sock *sk,
struct sk_buff *skb)
{
int rc;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(skb, LLC_PDU_TYPE_I, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_i_cmd(skb, llc->ack_pf, llc->vS, llc->vR);
rc = llc_mac_hdr_init(skb, llc->dev->dev_addr, llc->daddr.mac);
if (likely(!rc)) {
skb_get(skb);
llc_conn_send_pdu(sk, skb);
llc_conn_ac_inc_vs_by_1(sk, skb);
}
return rc;
}
/**
* llc_conn_ac_send_i_as_ack - sends an I-format PDU to acknowledge rx PDUs
* @sk: current connection structure.
* @skb: current event.
*
* This action sends an I-format PDU as acknowledge to received PDUs which
* have not been acknowledged, yet, if there is any. By using of this
* action number of acknowledgements decreases, this technic is called
* piggy backing. Returns 0 for success, 1 otherwise.
*/
int llc_conn_ac_send_i_as_ack(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
int ret;
if (llc->ack_must_be_send) {
ret = llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
llc->ack_must_be_send = 0 ;
llc->ack_pf = 0;
} else {
ret = llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
}
return ret;
}
/**
* llc_conn_ac_send_rr_rsp_f_set_ackpf - ack all rx PDUs not yet acked
* @sk: current connection structure.
* @skb: current event.
*
* This action sends an RR response with f-bit set to ack_pf flag as
* acknowledge to all received PDUs which have not been acknowledged, yet,
* if there is any. ack_pf flag indicates if a PDU has been received with
* p-bit set to one. Returns 0 for success, 1 otherwise.
*/
static int llc_conn_ac_send_rr_rsp_f_set_ackpf(struct sock *sk,
struct sk_buff *skb)
{
int rc = -ENOBUFS;
struct llc_sock *llc = llc_sk(sk);
struct sk_buff *nskb = llc_alloc_frame(sk, llc->dev, LLC_PDU_TYPE_S, 0);
if (nskb) {
struct llc_sap *sap = llc->sap;
llc_pdu_header_init(nskb, LLC_PDU_TYPE_S, sap->laddr.lsap,
llc->daddr.lsap, LLC_PDU_RSP);
llc_pdu_init_as_rr_rsp(nskb, llc->ack_pf, llc->vR);
rc = llc_mac_hdr_init(nskb, llc->dev->dev_addr, llc->daddr.mac);
if (unlikely(rc))
goto free;
llc_conn_send_pdu(sk, nskb);
}
out:
return rc;
free:
kfree_skb(nskb);
goto out;
}
/**
* llc_conn_ac_inc_npta_value - tries to make value of npta greater
* @sk: current connection structure.
* @skb: current event.
*
* After "inc_cntr" times calling of this action, "npta" increase by one.
* this action tries to make vale of "npta" greater as possible; number of
* acknowledgements decreases by increasing of "npta". Returns 0 for
* success, 1 otherwise.
*/
static int llc_conn_ac_inc_npta_value(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (!llc->inc_cntr) {
llc->dec_step = 0;
llc->dec_cntr = llc->inc_cntr = 2;
++llc->npta;
if (llc->npta > (u8) ~LLC_2_SEQ_NBR_MODULO)
llc->npta = (u8) ~LLC_2_SEQ_NBR_MODULO;
} else
--llc->inc_cntr;
return 0;
}
/**
* llc_conn_ac_adjust_npta_by_rr - decreases "npta" by one
* @sk: current connection structure.
* @skb: current event.
*
* After receiving "dec_cntr" times RR command, this action decreases
* "npta" by one. Returns 0 for success, 1 otherwise.
*/
int llc_conn_ac_adjust_npta_by_rr(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (!llc->connect_step && !llc->remote_busy_flag) {
if (!llc->dec_step) {
if (!llc->dec_cntr) {
llc->inc_cntr = llc->dec_cntr = 2;
if (llc->npta > 0)
llc->npta = llc->npta - 1;
} else
llc->dec_cntr -=1;
}
} else
llc->connect_step = 0 ;
return 0;
}
/**
* llc_conn_ac_adjust_npta_by_rnr - decreases "npta" by one
* @sk: current connection structure.
* @skb: current event.
*
* After receiving "dec_cntr" times RNR command, this action decreases
* "npta" by one. Returns 0 for success, 1 otherwise.
*/
int llc_conn_ac_adjust_npta_by_rnr(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (llc->remote_busy_flag)
if (!llc->dec_step) {
if (!llc->dec_cntr) {
llc->inc_cntr = llc->dec_cntr = 2;
if (llc->npta > 0)
--llc->npta;
} else
--llc->dec_cntr;
}
return 0;
}
/**
* llc_conn_ac_dec_tx_win_size - decreases tx window size
* @sk: current connection structure.
* @skb: current event.
*
* After receiving of a REJ command or response, transmit window size is
* decreased by number of PDUs which are outstanding yet. Returns 0 for
* success, 1 otherwise.
*/
int llc_conn_ac_dec_tx_win_size(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
u8 unacked_pdu = skb_queue_len(&llc->pdu_unack_q);
if (llc->k - unacked_pdu < 1)
llc->k = 1;
else
llc->k -= unacked_pdu;
return 0;
}
/**
* llc_conn_ac_inc_tx_win_size - tx window size is inc by 1
* @sk: current connection structure.
* @skb: current event.
*
* After receiving an RR response with f-bit set to one, transmit window
* size is increased by one. Returns 0 for success, 1 otherwise.
*/
int llc_conn_ac_inc_tx_win_size(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
llc->k += 1;
if (llc->k > (u8) ~LLC_2_SEQ_NBR_MODULO)
llc->k = (u8) ~LLC_2_SEQ_NBR_MODULO;
return 0;
}
int llc_conn_ac_stop_all_timers(struct sock *sk, struct sk_buff *skb)
{
llc_sk_stop_all_timers(sk, false);
return 0;
}
int llc_conn_ac_stop_other_timers(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
del_timer(&llc->rej_sent_timer.timer);
del_timer(&llc->pf_cycle_timer.timer);
del_timer(&llc->busy_state_timer.timer);
llc->ack_must_be_send = 0;
llc->ack_pf = 0;
return 0;
}
int llc_conn_ac_start_ack_timer(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
mod_timer(&llc->ack_timer.timer, jiffies + llc->ack_timer.expire);
return 0;
}
int llc_conn_ac_start_rej_timer(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
mod_timer(&llc->rej_sent_timer.timer,
jiffies + llc->rej_sent_timer.expire);
return 0;
}
int llc_conn_ac_start_ack_tmr_if_not_running(struct sock *sk,
struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
if (!timer_pending(&llc->ack_timer.timer))
mod_timer(&llc->ack_timer.timer,
jiffies + llc->ack_timer.expire);
return 0;
}
int llc_conn_ac_stop_ack_timer(struct sock *sk, struct sk_buff *skb)
{
del_timer(&llc_sk(sk)->ack_timer.timer);
return 0;
}
int llc_conn_ac_stop_p_timer(struct sock *sk, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(sk);
del_timer(&llc->pf_cycle_timer.timer);
llc_conn_set_p_flag(sk, 0);
return 0;
}
int llc_conn_ac_stop_rej_timer(struct sock *sk, struct sk_buff *skb)
{
del_timer(&llc_sk(sk)->rej_sent_timer.timer);
return 0;
}
int llc_conn_ac_upd_nr_received(struct sock *sk, struct sk_buff *skb)
{
int acked;
u16 unacked = 0;
struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
struct llc_sock *llc = llc_sk(sk);
llc->last_nr = PDU_SUPV_GET_Nr(pdu);
acked = llc_conn_remove_acked_pdus(sk, llc->last_nr, &unacked);
/* On loopback we don't queue I frames in unack_pdu_q queue. */
if (acked > 0 || (llc->dev->flags & IFF_LOOPBACK)) {
llc->retry_count = 0;
del_timer(&llc->ack_timer.timer);
if (llc->failed_data_req) {
/* already, we did not accept data from upper layer
* (tx_window full or unacceptable state). Now, we
* can send data and must inform to upper layer.
*/
llc->failed_data_req = 0;
llc_conn_ac_data_confirm(sk, skb);
}
if (unacked)
mod_timer(&llc->ack_timer.timer,
jiffies + llc->ack_timer.expire);
} else if (llc->failed_data_req) {
u8 f_bit;
llc_pdu_decode_pf_bit(skb, &f_bit);
if (f_bit == 1) {
llc->failed_data_req = 0;
llc_conn_ac_data_confirm(sk, skb);
}
}
return 0;
}
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_set_data_flag_2(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->data_flag = 2;
return 0;
}
int llc_conn_ac_set_data_flag_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->data_flag = 0;
return 0;
}
int llc_conn_ac_set_data_flag_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->data_flag = 1;
return 0;
}
int llc_conn_ac_set_data_flag_1_if_data_flag_eq_0(struct sock *sk,
struct sk_buff *skb)
{
if (!llc_sk(sk)->data_flag)
llc_sk(sk)->data_flag = 1;
return 0;
}
int llc_conn_ac_set_p_flag_0(struct sock *sk, struct sk_buff *skb)
{
llc_conn_set_p_flag(sk, 0);
return 0;
}
static int llc_conn_ac_set_p_flag_1(struct sock *sk, struct sk_buff *skb)
{
llc_conn_set_p_flag(sk, 1);
return 0;
}
int llc_conn_ac_set_remote_busy_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->remote_busy_flag = 0;
return 0;
}
int llc_conn_ac_set_cause_flag_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->cause_flag = 0;
return 0;
}
int llc_conn_ac_set_cause_flag_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->cause_flag = 1;
return 0;
}
int llc_conn_ac_set_retry_cnt_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->retry_count = 0;
return 0;
}
int llc_conn_ac_inc_retry_cnt_by_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->retry_count++;
return 0;
}
int llc_conn_ac_set_vr_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->vR = 0;
return 0;
}
int llc_conn_ac_inc_vr_by_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->vR = PDU_GET_NEXT_Vr(llc_sk(sk)->vR);
return 0;
}
int llc_conn_ac_set_vs_0(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->vS = 0;
return 0;
}
int llc_conn_ac_set_vs_nr(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->vS = llc_sk(sk)->last_nr;
return 0;
}
static int llc_conn_ac_inc_vs_by_1(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->vS = (llc_sk(sk)->vS + 1) % LLC_2_SEQ_NBR_MODULO;
return 0;
}
static void llc_conn_tmr_common_cb(struct sock *sk, u8 type)
{
struct sk_buff *skb = alloc_skb(0, GFP_ATOMIC);
bh_lock_sock(sk);
if (skb) {
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
skb_set_owner_r(skb, sk);
ev->type = type;
llc_process_tmr_ev(sk, skb);
}
bh_unlock_sock(sk);
}
void llc_conn_pf_cycle_tmr_cb(struct timer_list *t)
{
struct llc_sock *llc = from_timer(llc, t, pf_cycle_timer.timer);
llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_P_TMR);
}
void llc_conn_busy_tmr_cb(struct timer_list *t)
{
struct llc_sock *llc = from_timer(llc, t, busy_state_timer.timer);
llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_BUSY_TMR);
}
void llc_conn_ack_tmr_cb(struct timer_list *t)
{
struct llc_sock *llc = from_timer(llc, t, ack_timer.timer);
llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_ACK_TMR);
}
void llc_conn_rej_tmr_cb(struct timer_list *t)
{
struct llc_sock *llc = from_timer(llc, t, rej_sent_timer.timer);
llc_conn_tmr_common_cb(&llc->sk, LLC_CONN_EV_TYPE_REJ_TMR);
}
int llc_conn_ac_rst_vs(struct sock *sk, struct sk_buff *skb)
{
llc_sk(sk)->X = llc_sk(sk)->vS;
llc_conn_ac_set_vs_nr(sk, skb);
return 0;
}
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;
}
/*
* Non-standard actions; these not contained in IEEE specification; for
* our own usage
*/
/**
* llc_conn_disc - removes connection from SAP list and frees it
* @sk: closed connection
* @skb: occurred event
*/
int llc_conn_disc(struct sock *sk, struct sk_buff *skb)
{
/* FIXME: this thing seems to want to die */
return 0;
}
/**
* llc_conn_reset - resets connection
* @sk : reseting connection.
* @skb: occurred event.
*
* Stop all timers, empty all queues and reset all flags.
*/
int llc_conn_reset(struct sock *sk, struct sk_buff *skb)
{
llc_sk_reset(sk);
return 0;
}
/**
* llc_circular_between - designates that b is between a and c or not
* @a: lower bound
* @b: element to see if is between a and b
* @c: upper bound
*
* This function designates that b is between a and c or not (for example,
* 0 is between 127 and 1). Returns 1 if b is between a and c, 0
* otherwise.
*/
u8 llc_circular_between(u8 a, u8 b, u8 c)
{
b = b - a;
c = c - a;
return b <= c;
}
/**
* llc_process_tmr_ev - timer backend
* @sk: active connection
* @skb: occurred event
*
* This function is called from timer callback functions. When connection
* is busy (during sending a data frame) timer expiration event must be
* queued. Otherwise this event can be sent to connection state machine.
* Queued events will process by llc_backlog_rcv function after sending
* data frame.
*/
static void llc_process_tmr_ev(struct sock *sk, struct sk_buff *skb)
{
if (llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) {
printk(KERN_WARNING "%s: timer called on closed connection\n",
__func__);
kfree_skb(skb);
} else {
if (!sock_owned_by_user(sk))
llc_conn_state_process(sk, skb);
else {
llc_set_backlog_type(skb, LLC_EVENT);
__sk_add_backlog(sk, skb);
}
}
}