[net-next-2.6.git] / include / net / llc_pdu.h

#ifndef LLC_PDU_H
#define LLC_PDU_H
/*
 * 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/if_ether.h>
#include <linux/if_tr.h>

/* Lengths of frame formats */
#define LLC_PDU_LEN_I	4       /* header and 2 control bytes */
#define LLC_PDU_LEN_S	4
#define LLC_PDU_LEN_U	3       /* header and 1 control byte */
/* Known SAP addresses */
#define LLC_GLOBAL_SAP	0xFF
#define LLC_NULL_SAP	0x00	/* not network-layer visible */
#define LLC_MGMT_INDIV	0x02	/* station LLC mgmt indiv addr */
#define LLC_MGMT_GRP	0x03	/* station LLC mgmt group addr */
#define LLC_RDE_SAP	0xA6	/* route ... */

/* SAP field bit masks */
#define LLC_ISO_RESERVED_SAP	0x02
#define LLC_SAP_GROUP_DSAP	0x01
#define LLC_SAP_RESP_SSAP	0x01

/* Group/individual DSAP indicator is DSAP field */
#define LLC_PDU_GROUP_DSAP_MASK    0x01
#define LLC_PDU_IS_GROUP_DSAP(pdu)      \
	((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
#define LLC_PDU_IS_INDIV_DSAP(pdu)      \
	(!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)

/* Command/response PDU indicator in SSAP field */
#define LLC_PDU_CMD_RSP_MASK	0x01
#define LLC_PDU_CMD		0
#define LLC_PDU_RSP		1
#define LLC_PDU_IS_CMD(pdu)    ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1)
#define LLC_PDU_IS_RSP(pdu)    ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0)

/* Get PDU type from 2 lowest-order bits of control field first byte */
#define LLC_PDU_TYPE_I_MASK    0x01	/* 16-bit control field */
#define LLC_PDU_TYPE_S_MASK    0x03
#define LLC_PDU_TYPE_U_MASK    0x03	/* 8-bit control field */
#define LLC_PDU_TYPE_MASK      0x03

#define LLC_PDU_TYPE_I	0	/* first bit */
#define LLC_PDU_TYPE_S	1	/* first two bits */
#define LLC_PDU_TYPE_U	3	/* first two bits */

#define LLC_PDU_TYPE_IS_I(pdu) \
	((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)

#define LLC_PDU_TYPE_IS_U(pdu) \
	(((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)

#define LLC_PDU_TYPE_IS_S(pdu) \
	(((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)

/* U-format PDU control field masks */
#define LLC_U_PF_BIT_MASK      0x10	/* P/F bit mask */
#define LLC_U_PF_IS_1(pdu)     ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
#define LLC_U_PF_IS_0(pdu)     ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)

#define LLC_U_PDU_CMD_MASK     0xEC	/* cmd/rsp mask */
#define LLC_U_PDU_CMD(pdu)     (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
#define LLC_U_PDU_RSP(pdu)     (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)

#define LLC_1_PDU_CMD_UI       0x00	/* Type 1 cmds/rsps */
#define LLC_1_PDU_CMD_XID      0xAC
#define LLC_1_PDU_CMD_TEST     0xE0

#define LLC_2_PDU_CMD_SABME    0x6C	/* Type 2 cmds/rsps */
#define LLC_2_PDU_CMD_DISC     0x40
#define LLC_2_PDU_RSP_UA       0x60
#define LLC_2_PDU_RSP_DM       0x0C
#define LLC_2_PDU_RSP_FRMR     0x84

/* Type 1 operations */

/* XID information field bit masks */

/* LLC format identifier (byte 1) */
#define LLC_XID_FMT_ID		0x81	/* first byte must be this */

/* LLC types/classes identifier (byte 2) */
#define LLC_XID_CLASS_ZEROS_MASK	0xE0	/* these must be zeros */
#define LLC_XID_CLASS_MASK		0x1F	/* AND with byte to get below */

#define LLC_XID_NULL_CLASS_1	0x01	/* if NULL LSAP...use these */
#define LLC_XID_NULL_CLASS_2	0x03
#define LLC_XID_NULL_CLASS_3	0x05
#define LLC_XID_NULL_CLASS_4	0x07

#define LLC_XID_NNULL_TYPE_1	0x01	/* if non-NULL LSAP...use these */
#define LLC_XID_NNULL_TYPE_2	0x02
#define LLC_XID_NNULL_TYPE_3	0x04
#define LLC_XID_NNULL_TYPE_1_2	0x03
#define LLC_XID_NNULL_TYPE_1_3	0x05
#define LLC_XID_NNULL_TYPE_2_3	0x06
#define LLC_XID_NNULL_ALL		0x07

/* Sender Receive Window (byte 3) */
#define LLC_XID_RW_MASK	0xFE	/* AND with value to get below */

#define LLC_XID_MIN_RW	0x02	/* lowest-order bit always zero */

/* Type 2 operations */

#define LLC_2_SEQ_NBR_MODULO   ((u8) 128)

/* I-PDU masks ('ctrl' is I-PDU control word) */
#define LLC_I_GET_NS(pdu)     (u8)((pdu->ctrl_1 & 0xFE) >> 1)
#define LLC_I_GET_NR(pdu)     (u8)((pdu->ctrl_2 & 0xFE) >> 1)

#define LLC_I_PF_BIT_MASK      0x01

#define LLC_I_PF_IS_0(pdu)     ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
#define LLC_I_PF_IS_1(pdu)     ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)

/* S-PDU supervisory commands and responses */

#define LLC_S_PDU_CMD_MASK     0x0C
#define LLC_S_PDU_CMD(pdu)     (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
#define LLC_S_PDU_RSP(pdu)     (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)

#define LLC_2_PDU_CMD_RR       0x00	/* rx ready cmd */
#define LLC_2_PDU_RSP_RR       0x00	/* rx ready rsp */
#define LLC_2_PDU_CMD_REJ      0x08	/* reject PDU cmd */
#define LLC_2_PDU_RSP_REJ      0x08	/* reject PDU rsp */
#define LLC_2_PDU_CMD_RNR      0x04	/* rx not ready cmd */
#define LLC_2_PDU_RSP_RNR      0x04	/* rx not ready rsp */

#define LLC_S_PF_BIT_MASK      0x01
#define LLC_S_PF_IS_0(pdu)     ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
#define LLC_S_PF_IS_1(pdu)     ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)

#define PDU_SUPV_GET_Nr(pdu)   ((pdu->ctrl_2 & 0xFE) >> 1)
#define PDU_GET_NEXT_Vr(sn)    (++sn & ~LLC_2_SEQ_NBR_MODULO)

/* FRMR information field macros */

#define FRMR_INFO_LENGTH       5	/* 5 bytes of information */

/*
 * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
 * (if U-PDU) or word pointer to rejected PDU control field
 */
#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
	info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \
				LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
				(u16)*((u16 *) rej_ctrl) : \
				(((u16) *((u8 *) rej_ctrl)) & 0x00FF))

/*
 * Info is pointer to FRMR info field structure; 'vs' is a byte containing
 * send state variable value in low-order 7 bits (insure the lowest-order
 * bit remains zero (0))
 */
#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))

/*
 * Info is pointer to FRMR info field structure; 'cr' is a byte containing
 * the C/R bit value in the low-order bit
 */
#define FRMR_INFO_SET_C_R_BIT(info, cr)  (info->curr_rsv |= (((u8) cr) & 0x01))

/*
 * In the remaining five macros, 'info' is pointer to FRMR info field
 * structure; 'ind' is a byte containing the bit value to set in the
 * lowest-order bit)
 */
#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
       (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01)))

#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
       (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02)))

#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
       (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04)))

#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
       (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08)))

#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
       (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10)))

/* Sequence-numbered PDU format (4 bytes in length) */
struct llc_pdu_sn {
	u8 dsap;
	u8 ssap;
	u8 ctrl_1;
	u8 ctrl_2;
};

static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb)
{
	return (struct llc_pdu_sn *)skb_network_header(skb);
}

/* Un-numbered PDU format (3 bytes in length) */
struct llc_pdu_un {
	u8 dsap;
	u8 ssap;
	u8 ctrl_1;
};

static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb)
{
	return (struct llc_pdu_un *)skb_network_header(skb);
}

/**
 *	llc_pdu_header_init - initializes pdu header
 *	@skb: input skb that header must be set into it.
 *	@type: type of PDU (U, I or S).
 *	@ssap: source sap.
 *	@dsap: destination sap.
 *	@cr: command/response bit (0 or 1).
 *
 *	This function sets DSAP, SSAP and command/Response bit in LLC header.
 */
static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
				       u8 ssap, u8 dsap, u8 cr)
{
	const int hlen = type == LLC_PDU_TYPE_U ? 3 : 4;
	struct llc_pdu_un *pdu;

	skb_push(skb, hlen);
	skb_reset_network_header(skb);
	pdu = llc_pdu_un_hdr(skb);
	pdu->dsap = dsap;
	pdu->ssap = ssap;
	pdu->ssap |= cr;
}

/**
 *	llc_pdu_decode_sa - extracs source address (MAC) of input frame
 *	@skb: input skb that source address must be extracted from it.
 *	@sa: pointer to source address (6 byte array).
 *
 *	This function extracts source address(MAC) of input frame.
 */
static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa)
{
	if (skb->protocol == htons(ETH_P_802_2))
		memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
	else if (skb->protocol == htons(ETH_P_TR_802_2)) {
		memcpy(sa, tr_hdr(skb)->saddr, ETH_ALEN);
		*sa &= 0x7F;
	}
}

/**
 *	llc_pdu_decode_da - extracts dest address of input frame
 *	@skb: input skb that destination address must be extracted from it
 *	@sa: pointer to destination address (6 byte array).
 *
 *	This function extracts destination address(MAC) of input frame.
 */
static inline void llc_pdu_decode_da(struct sk_buff *skb, u8 *da)
{
	if (skb->protocol == htons(ETH_P_802_2))
		memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
	else if (skb->protocol == htons(ETH_P_TR_802_2))
		memcpy(da, tr_hdr(skb)->daddr, ETH_ALEN);
}

/**
 *	llc_pdu_decode_ssap - extracts source SAP of input frame
 *	@skb: input skb that source SAP must be extracted from it.
 *	@ssap: source SAP (output argument).
 *
 *	This function extracts source SAP of input frame. Right bit of SSAP is
 *	command/response bit.
 */
static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap)
{
	*ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
}

/**
 *	llc_pdu_decode_dsap - extracts dest SAP of input frame
 *	@skb: input skb that destination SAP must be extracted from it.
 *	@dsap: destination SAP (output argument).
 *
 *	This function extracts destination SAP of input frame. right bit of
 *	DSAP designates individual/group SAP.
 */
static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap)
{
	*dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
}

/**
 *	llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
 *	@skb: input skb that header must be set into it.
 *
 *	This function sets third byte of LLC header as a UI PDU.
 */
static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
{
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	pdu->ctrl_1  = LLC_PDU_TYPE_U;
	pdu->ctrl_1 |= LLC_1_PDU_CMD_UI;
}

/**
 *	llc_pdu_init_as_test_cmd - sets PDU as TEST
 *	@skb - Address of the skb to build
 *
 * 	Sets a PDU as TEST
 */
static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
{
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	pdu->ctrl_1  = LLC_PDU_TYPE_U;
	pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
	pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
}

/**
 *	llc_pdu_init_as_test_rsp - build TEST response PDU
 *	@skb: Address of the skb to build
 *	@ev_skb: The received TEST command PDU frame
 *
 *	Builds a pdu frame as a TEST response.
 */
static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
					    struct sk_buff *ev_skb)
{
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	pdu->ctrl_1  = LLC_PDU_TYPE_U;
	pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
	pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
	if (ev_skb->protocol == htons(ETH_P_802_2)) {
		struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
		int dsize;

		dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
		memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize);
		skb_put(skb, dsize);
	}
}

/* LLC Type 1 XID command/response information fields format */
struct llc_xid_info {
	u8 fmt_id;	/* always 0x81 for LLC */
	u8 type;	/* different if NULL/non-NULL LSAP */
	u8 rw;		/* sender receive window */
};

/**
 *	llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
 *	@skb: input skb that header must be set into it.
 *
 *	This function sets third,fourth,fifth and sixth bytes of LLC header as
 *	a XID PDU.
 */
static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
					   u8 svcs_supported, u8 rx_window)
{
	struct llc_xid_info *xid_info;
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	pdu->ctrl_1	 = LLC_PDU_TYPE_U;
	pdu->ctrl_1	|= LLC_1_PDU_CMD_XID;
	pdu->ctrl_1	|= LLC_U_PF_BIT_MASK;
	xid_info	 = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
	xid_info->fmt_id = LLC_XID_FMT_ID;	/* 0x81 */
	xid_info->type	 = svcs_supported;
	xid_info->rw	 = rx_window << 1;	/* size of receive window */
	skb_put(skb, sizeof(struct llc_xid_info));
}

/**
 *	llc_pdu_init_as_xid_rsp - builds XID response PDU
 *	@skb: Address of the skb to build
 *	@svcs_supported: The class of the LLC (I or II)
 *	@rx_window: The size of the receive window of the LLC
 *
 *	Builds a pdu frame as an XID response.
 */
static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
					   u8 svcs_supported, u8 rx_window)
{
	struct llc_xid_info *xid_info;
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	pdu->ctrl_1	 = LLC_PDU_TYPE_U;
	pdu->ctrl_1	|= LLC_1_PDU_CMD_XID;
	pdu->ctrl_1	|= LLC_U_PF_BIT_MASK;

	xid_info	 = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
	xid_info->fmt_id = LLC_XID_FMT_ID;
	xid_info->type	 = svcs_supported;
	xid_info->rw	 = rx_window << 1;
	skb_put(skb, sizeof(struct llc_xid_info));
}

/* LLC Type 2 FRMR response information field format */
struct llc_frmr_info {
	u16 rej_pdu_ctrl;	/* bits 1-8 if U-PDU */
	u8  curr_ssv;		/* current send state variable val */
	u8  curr_rsv;		/* current receive state variable */
	u8  ind_bits;		/* indicator bits set with macro */
};

extern void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
extern void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
extern void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit);
extern void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
extern void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
extern void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
extern void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
extern void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
extern void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
extern void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
extern 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);
extern void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
extern void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
extern void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
extern void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
#endif /* LLC_PDU_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef LLC_PDU_H
	2	#define LLC_PDU_H
	3	/*
	4	* Copyright (c) 1997 by Procom Technology,Inc.
	5	* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
	6	*
	7	* This program can be redistributed or modified under the terms of the
	8	* GNU General Public License as published by the Free Software Foundation.
	9	* This program is distributed without any warranty or implied warranty
	10	* of merchantability or fitness for a particular purpose.
	11	*
	12	* See the GNU General Public License for more details.
	13	*/
	14
	15	#include <linux/if_ether.h>
	16	#include <linux/if_tr.h>
	17
	18	/* Lengths of frame formats */
	19	#define LLC_PDU_LEN_I 4 /* header and 2 control bytes */
	20	#define LLC_PDU_LEN_S 4
	21	#define LLC_PDU_LEN_U 3 /* header and 1 control byte */
	22	/* Known SAP addresses */
	23	#define LLC_GLOBAL_SAP 0xFF
	24	#define LLC_NULL_SAP 0x00 /* not network-layer visible */
	25	#define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */
	26	#define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */
	27	#define LLC_RDE_SAP 0xA6 /* route ... */
	28
	29	/* SAP field bit masks */
	30	#define LLC_ISO_RESERVED_SAP 0x02
	31	#define LLC_SAP_GROUP_DSAP 0x01
	32	#define LLC_SAP_RESP_SSAP 0x01
	33
	34	/* Group/individual DSAP indicator is DSAP field */
	35	#define LLC_PDU_GROUP_DSAP_MASK 0x01
	36	#define LLC_PDU_IS_GROUP_DSAP(pdu) \
	37	((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
	38	#define LLC_PDU_IS_INDIV_DSAP(pdu) \
	39	(!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
	40
	41	/* Command/response PDU indicator in SSAP field */
	42	#define LLC_PDU_CMD_RSP_MASK 0x01
	43	#define LLC_PDU_CMD 0
	44	#define LLC_PDU_RSP 1
	45	#define LLC_PDU_IS_CMD(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1)
	46	#define LLC_PDU_IS_RSP(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0)
	47
	48	/* Get PDU type from 2 lowest-order bits of control field first byte */
	49	#define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */
	50	#define LLC_PDU_TYPE_S_MASK 0x03
	51	#define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */
	52	#define LLC_PDU_TYPE_MASK 0x03
	53
	54	#define LLC_PDU_TYPE_I 0 /* first bit */
	55	#define LLC_PDU_TYPE_S 1 /* first two bits */
	56	#define LLC_PDU_TYPE_U 3 /* first two bits */
	57
	58	#define LLC_PDU_TYPE_IS_I(pdu) \
	59	((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)
	60
	61	#define LLC_PDU_TYPE_IS_U(pdu) \
	62	(((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)
	63
	64	#define LLC_PDU_TYPE_IS_S(pdu) \
65	(((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)
66
67	/* U-format PDU control field masks */
68	#define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */
69	#define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
70	#define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)
71
72	#define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */
73	#define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
74	#define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
75
76	#define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */
77	#define LLC_1_PDU_CMD_XID 0xAC
78	#define LLC_1_PDU_CMD_TEST 0xE0
79
80	#define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */
81	#define LLC_2_PDU_CMD_DISC 0x40
82	#define LLC_2_PDU_RSP_UA 0x60
83	#define LLC_2_PDU_RSP_DM 0x0C
84	#define LLC_2_PDU_RSP_FRMR 0x84
85
86	/* Type 1 operations */
87
88	/* XID information field bit masks */
89
90	/* LLC format identifier (byte 1) */
91	#define LLC_XID_FMT_ID 0x81 /* first byte must be this */
92
93	/* LLC types/classes identifier (byte 2) */
94	#define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */
95	#define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */
96
97	#define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */
98	#define LLC_XID_NULL_CLASS_2 0x03
99	#define LLC_XID_NULL_CLASS_3 0x05
100	#define LLC_XID_NULL_CLASS_4 0x07
101
102	#define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */
103	#define LLC_XID_NNULL_TYPE_2 0x02
104	#define LLC_XID_NNULL_TYPE_3 0x04
105	#define LLC_XID_NNULL_TYPE_1_2 0x03
106	#define LLC_XID_NNULL_TYPE_1_3 0x05
107	#define LLC_XID_NNULL_TYPE_2_3 0x06
108	#define LLC_XID_NNULL_ALL 0x07
109
110	/* Sender Receive Window (byte 3) */
111	#define LLC_XID_RW_MASK 0xFE /* AND with value to get below */
112
113	#define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */
114
115	/* Type 2 operations */
116
117	#define LLC_2_SEQ_NBR_MODULO ((u8) 128)
118
119	/* I-PDU masks ('ctrl' is I-PDU control word) */
120	#define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1)
121	#define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1)
122
123	#define LLC_I_PF_BIT_MASK 0x01
124
125	#define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
126	#define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)
127
128	/* S-PDU supervisory commands and responses */
129
130	#define LLC_S_PDU_CMD_MASK 0x0C
131	#define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
132	#define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
133
134	#define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */
135	#define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */
136	#define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */
137	#define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */
138	#define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */
139	#define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */
140
141	#define LLC_S_PF_BIT_MASK 0x01
142	#define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
143	#define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)
144
145	#define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1)
146	#define PDU_GET_NEXT_Vr(sn) (++sn & ~LLC_2_SEQ_NBR_MODULO)
147
148	/* FRMR information field macros */
149
150	#define FRMR_INFO_LENGTH 5 /* 5 bytes of information */
151
152	/*
153	* info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
154	* (if U-PDU) or word pointer to rejected PDU control field
155	*/
156	#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
157	info->rej_pdu_ctrl = ((((u8 ) rej_ctrl) & \
158	LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
159	(u16)((u16 ) rej_ctrl) : \
160	(((u16) ((u8 ) rej_ctrl)) & 0x00FF))
161
162	/*
163	* Info is pointer to FRMR info field structure; 'vs' is a byte containing
164	* send state variable value in low-order 7 bits (insure the lowest-order
165	* bit remains zero (0))
166	*/
167	#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
168	#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))
169
170	/*
171	* Info is pointer to FRMR info field structure; 'cr' is a byte containing
172	* the C/R bit value in the low-order bit
173	*/
174	#define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv \|= (((u8) cr) & 0x01))
175
176	/*
177	* In the remaining five macros, 'info' is pointer to FRMR info field
178	* structure; 'ind' is a byte containing the bit value to set in the
179	* lowest-order bit)
180	*/
181	#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
182	(info->ind_bits = ((info->ind_bits & 0xFE) \| (((u8) ind) & 0x01)))
183
184	#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
185	(info->ind_bits = ( (info->ind_bits & 0xFD) \| (((u8) ind) & 0x02)))
186
187	#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
188	(info->ind_bits = ( (info->ind_bits & 0xFB) \| (((u8) ind) & 0x04)))
189
190	#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
191	(info->ind_bits = ( (info->ind_bits & 0xF7) \| (((u8) ind) & 0x08)))
192
193	#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
194	(info->ind_bits = ( (info->ind_bits & 0xEF) \| (((u8) ind) & 0x10)))
195
196	/* Sequence-numbered PDU format (4 bytes in length) */
197	struct llc_pdu_sn {
198	u8 dsap;
199	u8 ssap;
200	u8 ctrl_1;
201	u8 ctrl_2;
202	};
203
204	static inline struct llc_pdu_sn llc_pdu_sn_hdr(struct sk_buff skb)
205	{
d56f90a7	206	return (struct llc_pdu_sn *)skb_network_header(skb);
1da177e4 LT	207	}
	208
	209	/* Un-numbered PDU format (3 bytes in length) */
	210	struct llc_pdu_un {
	211	u8 dsap;
	212	u8 ssap;
	213	u8 ctrl_1;
	214	};
	215
	216	static inline struct llc_pdu_un llc_pdu_un_hdr(struct sk_buff skb)
	217	{
d56f90a7	218	return (struct llc_pdu_un *)skb_network_header(skb);
1da177e4 LT	219	}
1da177e4 LT	220
1da177e4 LT	221	/**
	222	* llc_pdu_header_init - initializes pdu header
	223	* @skb: input skb that header must be set into it.
	224	* @type: type of PDU (U, I or S).
	225	* @ssap: source sap.
	226	* @dsap: destination sap.
	227	* @cr: command/response bit (0 or 1).
	228	*
	229	* This function sets DSAP, SSAP and command/Response bit in LLC header.
	230	*/
	231	static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
	232	u8 ssap, u8 dsap, u8 cr)
	233	{
	234	const int hlen = type == LLC_PDU_TYPE_U ? 3 : 4;
37e66366 ACM	235	struct llc_pdu_un *pdu;
	236
	237	skb_push(skb, hlen);
c1d2bbe1	238	skb_reset_network_header(skb);
37e66366	239	pdu = llc_pdu_un_hdr(skb);
1da177e4 LT	240	pdu->dsap = dsap;
	241	pdu->ssap = ssap;
	242	pdu->ssap \|= cr;
	243	}
	244
	245	/**
	246	* llc_pdu_decode_sa - extracs source address (MAC) of input frame
	247	* @skb: input skb that source address must be extracted from it.
	248	* @sa: pointer to source address (6 byte array).
	249	*
	250	* This function extracts source address(MAC) of input frame.
	251	*/
	252	static inline void llc_pdu_decode_sa(struct sk_buff skb, u8 sa)
	253	{
3fbd418a	254	if (skb->protocol == htons(ETH_P_802_2))
1da177e4	255	memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
3fbd418a	256	else if (skb->protocol == htons(ETH_P_TR_802_2)) {
1da177e4	257	memcpy(sa, tr_hdr(skb)->saddr, ETH_ALEN);
5ed688a7 JF	258	*sa &= 0x7F;
5ed688a7 JF	259	}
1da177e4 LT	260	}
	261
	262	/**
	263	* llc_pdu_decode_da - extracts dest address of input frame
	264	* @skb: input skb that destination address must be extracted from it
	265	* @sa: pointer to destination address (6 byte array).
	266	*
	267	* This function extracts destination address(MAC) of input frame.
	268	*/
	269	static inline void llc_pdu_decode_da(struct sk_buff skb, u8 da)
	270	{
3fbd418a	271	if (skb->protocol == htons(ETH_P_802_2))
1da177e4	272	memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
3fbd418a	273	else if (skb->protocol == htons(ETH_P_TR_802_2))
1da177e4 LT	274	memcpy(da, tr_hdr(skb)->daddr, ETH_ALEN);
	275	}
	276
	277	/**
	278	* llc_pdu_decode_ssap - extracts source SAP of input frame
	279	* @skb: input skb that source SAP must be extracted from it.
	280	* @ssap: source SAP (output argument).
	281	*
	282	* This function extracts source SAP of input frame. Right bit of SSAP is
	283	* command/response bit.
	284	*/
	285	static inline void llc_pdu_decode_ssap(struct sk_buff skb, u8 ssap)
	286	{
	287	*ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
	288	}
	289
	290	/**
	291	* llc_pdu_decode_dsap - extracts dest SAP of input frame
	292	* @skb: input skb that destination SAP must be extracted from it.
	293	* @dsap: destination SAP (output argument).
	294	*
	295	* This function extracts destination SAP of input frame. right bit of
	296	* DSAP designates individual/group SAP.
	297	*/
	298	static inline void llc_pdu_decode_dsap(struct sk_buff skb, u8 dsap)
	299	{
	300	*dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
	301	}
	302
	303	/**
	304	* llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
	305	* @skb: input skb that header must be set into it.
	306	*
	307	* This function sets third byte of LLC header as a UI PDU.
	308	*/
	309	static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
	310	{
	311	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	312
	313	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	314	pdu->ctrl_1 \|= LLC_1_PDU_CMD_UI;
	315	}
	316
	317	/**
	318	* llc_pdu_init_as_test_cmd - sets PDU as TEST
	319	* @skb - Address of the skb to build
	320	*
	321	* Sets a PDU as TEST
	322	*/
	323	static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
	324	{
	325	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	326
	327	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	328	pdu->ctrl_1 \|= LLC_1_PDU_CMD_TEST;
	329	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	330	}
	331
	332	/**
	333	* llc_pdu_init_as_test_rsp - build TEST response PDU
	334	* @skb: Address of the skb to build
	335	* @ev_skb: The received TEST command PDU frame
	336	*
	337	* Builds a pdu frame as a TEST response.
338	*/
339	static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
340	struct sk_buff *ev_skb)
341	{
342	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
343
344	pdu->ctrl_1 = LLC_PDU_TYPE_U;
345	pdu->ctrl_1 \|= LLC_1_PDU_CMD_TEST;
346	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
3fbd418a	347	if (ev_skb->protocol == htons(ETH_P_802_2)) {
1da177e4 LT	348	struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
	349	int dsize;
	350
	351	dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
	352	memcpy(((u8 )pdu) + 3, ((u8 )ev_pdu) + 3, dsize);
	353	skb_put(skb, dsize);
	354	}
	355	}
	356
	357	/* LLC Type 1 XID command/response information fields format */
	358	struct llc_xid_info {
cf225356	359	u8 fmt_id; /* always 0x81 for LLC */
1da177e4 LT	360	u8 type; /* different if NULL/non-NULL LSAP */
	361	u8 rw; /* sender receive window */
	362	};
	363
	364	/**
	365	* llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
	366	* @skb: input skb that header must be set into it.
	367	*
	368	* This function sets third,fourth,fifth and sixth bytes of LLC header as
	369	* a XID PDU.
	370	*/
	371	static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
	372	u8 svcs_supported, u8 rx_window)
	373	{
	374	struct llc_xid_info *xid_info;
	375	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	376
	377	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	378	pdu->ctrl_1 \|= LLC_1_PDU_CMD_XID;
	379	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	380	xid_info = (struct llc_xid_info )(((u8 )&pdu->ctrl_1) + 1);
	381	xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */
	382	xid_info->type = svcs_supported;
	383	xid_info->rw = rx_window << 1; /* size of receive window */
f83f1768	384	skb_put(skb, sizeof(struct llc_xid_info));
1da177e4 LT	385	}
	386
	387	/**
	388	* llc_pdu_init_as_xid_rsp - builds XID response PDU
	389	* @skb: Address of the skb to build
	390	* @svcs_supported: The class of the LLC (I or II)
	391	* @rx_window: The size of the receive window of the LLC
	392	*
	393	* Builds a pdu frame as an XID response.
	394	*/
	395	static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
	396	u8 svcs_supported, u8 rx_window)
	397	{
	398	struct llc_xid_info *xid_info;
	399	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	400
	401	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	402	pdu->ctrl_1 \|= LLC_1_PDU_CMD_XID;
	403	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	404
	405	xid_info = (struct llc_xid_info )(((u8 )&pdu->ctrl_1) + 1);
	406	xid_info->fmt_id = LLC_XID_FMT_ID;
	407	xid_info->type = svcs_supported;
	408	xid_info->rw = rx_window << 1;
f83f1768	409	skb_put(skb, sizeof(struct llc_xid_info));
1da177e4 LT	410	}
	411
	412	/* LLC Type 2 FRMR response information field format */
	413	struct llc_frmr_info {
	414	u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */
	415	u8 curr_ssv; /* current send state variable val */
	416	u8 curr_rsv; /* current receive state variable */
	417	u8 ind_bits; /* indicator bits set with macro */
	418	};
	419
	420	extern void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
	421	extern void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
	422	extern void llc_pdu_decode_pf_bit(struct sk_buff skb, u8 pf_bit);
	423	extern void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
	424	extern void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
	425	extern void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	426	extern void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	427	extern void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	428	extern void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
	429	extern void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
	430	extern void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb,
	431	struct llc_pdu_sn *prev_pdu,
	432	u8 f_bit, u8 vs, u8 vr, u8 vzyxw);
	433	extern void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	434	extern void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	435	extern void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	436	extern void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
	437	#endif /* LLC_PDU_H */