Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 * llc_pdu.c - access to PDU internals

 *

 * 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 <net/llc_pdu.h>

static void llc_pdu_decode_pdu_type(struct sk_buff *skb, u8 *type);

static u8 llc_pdu_get_pf_bit(struct llc_pdu_sn *pdu);

void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 pdu_type)

{

        llc_pdu_un_hdr(skb)->ssap |= pdu_type;

}

/**

 *      pdu_set_pf_bit - sets poll/final bit in LLC header

 *      @pdu_frame: input frame that p/f bit must be set into it.

 *      @bit_value: poll/final bit (0 or 1).

 *

 *      This function sets poll/final bit in LLC header (based on type of PDU).

 *      in I or S pdus, p/f bit is right bit of fourth byte in header. in U

 *      pdus p/f bit is fifth bit of third byte.

 */

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;

        }

}

/**

 *      llc_pdu_decode_pf_bit - extracs poll/final bit from LLC header

 *      @skb: input skb that p/f bit must be extracted from it

 *      @pf_bit: poll/final bit (0 or 1)

 *

 *      This function extracts poll/final bit from LLC header (based on type of

 *      PDU). In I or S pdus, p/f bit is right bit of fourth byte in header. In

 *      U pdus p/f bit is fifth bit of third byte.

 */

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_pdu_init_as_disc_cmd - Builds DISC PDU

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *

 *      Builds a pdu frame as a DISC command.

 */

void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit)

{

        struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

        pdu->ctrl_1  = LLC_PDU_TYPE_U;

        pdu->ctrl_1 |= LLC_2_PDU_CMD_DISC;

        pdu->ctrl_1 |= ((p_bit & 1) << 4) & LLC_U_PF_BIT_MASK;

}

/**

 *      llc_pdu_init_as_i_cmd - builds I pdu

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *      @ns: The sequence number of the data PDU

 *      @nr: The seq. number of the expected I PDU from the remote

 *

 *      Builds a pdu frame as an I command.

 */

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); /* p/f bit */

        pdu->ctrl_1 |= (ns << 1) & 0xFE;   /* set N(S) in bits 2..8 */

        pdu->ctrl_2 |= (nr << 1) & 0xFE;   /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_rej_cmd - builds REJ PDU

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *      @nr: The seq. number of the expected I PDU from the remote

 *

 *      Builds a pdu frame as a REJ command.

 */

void llc_pdu_init_as_rej_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_REJ;

        pdu->ctrl_2  = 0;

        pdu->ctrl_2 |= p_bit & LLC_S_PF_BIT_MASK;

        pdu->ctrl_1 &= 0x0F;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_rnr_cmd - builds RNR pdu

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *      @nr: The seq. number of the expected I PDU from the remote

 *

 *      Builds a pdu frame as an RNR command.

 */

void llc_pdu_init_as_rnr_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_RNR;

        pdu->ctrl_2  = 0;

        pdu->ctrl_2 |= p_bit & LLC_S_PF_BIT_MASK;

        pdu->ctrl_1 &= 0x0F;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_rr_cmd - Builds RR pdu

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *      @nr: The seq. number of the expected I PDU from the remote

 *

 *      Builds a pdu frame as an RR command.

 */

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;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE; /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_sabme_cmd - builds SABME pdu

 *      @skb: Address of the skb to build

 *      @p_bit: The P bit to set in the PDU

 *

 *      Builds a pdu frame as an SABME command.

 */

void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit)

{

        struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

        pdu->ctrl_1  = LLC_PDU_TYPE_U;

        pdu->ctrl_1 |= LLC_2_PDU_CMD_SABME;

        pdu->ctrl_1 |= ((p_bit & 1) << 4) & LLC_U_PF_BIT_MASK;

}

/**

 *      llc_pdu_init_as_dm_rsp - builds DM response pdu

 *      @skb: Address of the skb to build

 *      @f_bit: The F bit to set in the PDU

 *

 *      Builds a pdu frame as a DM response.

 */

void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit)

{

        struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

        pdu->ctrl_1  = LLC_PDU_TYPE_U;

        pdu->ctrl_1 |= LLC_2_PDU_RSP_DM;

        pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK;

}

/**

 *      llc_pdu_init_as_frmr_rsp - builds FRMR response PDU

 *      @skb: Address of the frame to build

 *      @prev_pdu: The rejected PDU frame

 *      @f_bit: The F bit to set in the PDU

 *      @vs: tx state vari value for the data link conn at the rejecting LLC

 *      @vr: rx state var value for the data link conn at the rejecting LLC

 *      @vzyxw: completely described in the IEEE Std 802.2 document (Pg 55)

 *

 *      Builds a pdu frame as a FRMR response.

 */

void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu,

                              u8 f_bit, u8 vs, u8 vr, u8 vzyxw)

{

        struct llc_frmr_info *frmr_info;

        u8 prev_pf = 0;

        u8 *ctrl;

        struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);

        pdu->ctrl_1  = LLC_PDU_TYPE_U;

        pdu->ctrl_1 |= LLC_2_PDU_RSP_FRMR;

        pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK;

        frmr_info = (struct llc_frmr_info *)&pdu->ctrl_2;

        ctrl = (u8 *)&prev_pdu->ctrl_1;

        FRMR_INFO_SET_REJ_CNTRL(frmr_info,ctrl);

        FRMR_INFO_SET_Vs(frmr_info, vs);

        FRMR_INFO_SET_Vr(frmr_info, vr);

        prev_pf = llc_pdu_get_pf_bit(prev_pdu);

        FRMR_INFO_SET_C_R_BIT(frmr_info, prev_pf);

        FRMR_INFO_SET_INVALID_PDU_CTRL_IND(frmr_info, vzyxw);

        FRMR_INFO_SET_INVALID_PDU_INFO_IND(frmr_info, vzyxw);

        FRMR_INFO_SET_PDU_INFO_2LONG_IND(frmr_info, vzyxw);

        FRMR_INFO_SET_PDU_INVALID_Nr_IND(frmr_info, vzyxw);

        FRMR_INFO_SET_PDU_INVALID_Ns_IND(frmr_info, vzyxw);

        skb_put(skb, 5);

}

/**

 *      llc_pdu_init_as_rr_rsp - builds RR response pdu

 *      @skb: Address of the skb to build

 *      @f_bit: The F bit to set in the PDU

 *      @nr: The seq. number of the expected data PDU from the remote

 *

 *      Builds a pdu frame as an RR response.

 */

void llc_pdu_init_as_rr_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_RR;

        pdu->ctrl_2  = 0;

        pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK;

        pdu->ctrl_1 &= 0x0F;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE;  /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_rej_rsp - builds REJ response pdu

 *      @skb: Address of the skb to build

 *      @f_bit: The F bit to set in the PDU

 *      @nr: The seq. number of the expected data PDU from the remote

 *

 *      Builds a pdu frame as a REJ response.

 */

void llc_pdu_init_as_rej_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_REJ;

        pdu->ctrl_2  = 0;

        pdu->ctrl_2 |= f_bit & LLC_S_PF_BIT_MASK;

        pdu->ctrl_1 &= 0x0F;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE;  /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_rnr_rsp - builds RNR response pdu

 *      @skb: Address of the frame to build

 *      @f_bit: The F bit to set in the PDU

 *      @nr: The seq. number of the expected data PDU from the remote

 *

 *      Builds a pdu frame as an RNR response.

 */

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;    /* setting bits 5..8 to zero(reserved) */

        pdu->ctrl_2 |= (nr << 1) & 0xFE;  /* set N(R) in bits 10..16 */

}

/**

 *      llc_pdu_init_as_ua_rsp - builds UA response pdu

 *      @skb: Address of the frame to build

 *      @f_bit: The F bit to set in the PDU

 *

 *      Builds a pdu frame as a UA response.

 */

void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit)

{

        struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

        pdu->ctrl_1  = LLC_PDU_TYPE_U;

        pdu->ctrl_1 |= LLC_2_PDU_RSP_UA;

        pdu->ctrl_1 |= ((f_bit & 1) << 4) & LLC_U_PF_BIT_MASK;

}

/**

 *      llc_pdu_decode_pdu_type - designates PDU type

 *      @skb: input skb that type of it must be designated.

 *      @type: type of PDU (output argument).

 *

 *      This function designates type of PDU (I, S or U).

 */

static void llc_pdu_decode_pdu_type(struct sk_buff *skb, u8 *type)

{

        struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

        if (pdu->ctrl_1 & 1) {

                if ((pdu->ctrl_1 & LLC_PDU_TYPE_U) == LLC_PDU_TYPE_U)

                        *type = LLC_PDU_TYPE_U;

                else

                        *type = LLC_PDU_TYPE_S;

        } else

                *type = LLC_PDU_TYPE_I;

}

/**

 *      llc_pdu_get_pf_bit - extracts p/f bit of input PDU

 *      @pdu: pointer to LLC header.

 *

 *      This function extracts p/f bit of input PDU. at first examines type of

 *      PDU and then extracts p/f bit. Returns the p/f bit.

 */

static u8 llc_pdu_get_pf_bit(struct llc_pdu_sn *pdu)

{

        u8 pdu_type;

        u8 pf_bit = 0;

        if (pdu->ctrl_1 & 1) {

                if ((pdu->ctrl_1 & LLC_PDU_TYPE_U) == LLC_PDU_TYPE_U)

                        pdu_type = LLC_PDU_TYPE_U;

                else

                        pdu_type = LLC_PDU_TYPE_S;

        } else

                pdu_type = LLC_PDU_TYPE_I;

        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;

        }

        return pf_bit;

}