llc_c_ac.c

linux 内核源代码

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);

	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);

	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);

	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);

	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);

	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);

	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);

	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);

	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);

	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);

	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);

	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);

	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_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)) {
		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);

	if (llc->ack_must_be_send) {
		llc_conn_ac_send_i_rsp_f_set_ackpf(sk, skb);
		llc->ack_must_be_send = 0 ;
		llc->ack_pf = 0;
	} else
		llc_conn_ac_send_i_cmd_p_set_0(sk, skb);
	return 0;
}

/**
 *	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);

	if (nskb) {
		struct llc_sap *sap = llc->sap;