llc_c_ac.c

linux 内核源代码

/*
 * 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 <[e-mail]>
 *
 * 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 <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);

	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);

	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);

	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);
	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);

	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);
	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)) {
		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)) {
		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)) {
		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);

	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);

	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;
}