[mirror_ubuntu-bionic-kernel.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>

/* 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) + 1) & ~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;
} __packed;

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;
} __packed;

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);
}

/**
 *	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);
}

/**
 *	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 */
} __packed;

/**
 *	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 */
} __packed;

void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit);
void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
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);
void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
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>
1da177e4 LT	16
	17	/* Lengths of frame formats */
	18	#define LLC_PDU_LEN_I 4 /* header and 2 control bytes */
	19	#define LLC_PDU_LEN_S 4
	20	#define LLC_PDU_LEN_U 3 /* header and 1 control byte */
	21	/* Known SAP addresses */
	22	#define LLC_GLOBAL_SAP 0xFF
	23	#define LLC_NULL_SAP 0x00 /* not network-layer visible */
	24	#define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */
	25	#define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */
	26	#define LLC_RDE_SAP 0xA6 /* route ... */
	27
	28	/* SAP field bit masks */
	29	#define LLC_ISO_RESERVED_SAP 0x02
	30	#define LLC_SAP_GROUP_DSAP 0x01
	31	#define LLC_SAP_RESP_SSAP 0x01
	32
	33	/* Group/individual DSAP indicator is DSAP field */
	34	#define LLC_PDU_GROUP_DSAP_MASK 0x01
	35	#define LLC_PDU_IS_GROUP_DSAP(pdu) \
	36	((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
	37	#define LLC_PDU_IS_INDIV_DSAP(pdu) \
	38	(!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
	39
	40	/* Command/response PDU indicator in SSAP field */
	41	#define LLC_PDU_CMD_RSP_MASK 0x01
	42	#define LLC_PDU_CMD 0
	43	#define LLC_PDU_RSP 1
	44	#define LLC_PDU_IS_CMD(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1)
	45	#define LLC_PDU_IS_RSP(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0)
	46
	47	/* Get PDU type from 2 lowest-order bits of control field first byte */
	48	#define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */
	49	#define LLC_PDU_TYPE_S_MASK 0x03
	50	#define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */
	51	#define LLC_PDU_TYPE_MASK 0x03
	52
	53	#define LLC_PDU_TYPE_I 0 /* first bit */
	54	#define LLC_PDU_TYPE_S 1 /* first two bits */
	55	#define LLC_PDU_TYPE_U 3 /* first two bits */
	56
	57	#define LLC_PDU_TYPE_IS_I(pdu) \
	58	((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)
	59
	60	#define LLC_PDU_TYPE_IS_U(pdu) \
	61	(((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)
	62
	63	#define LLC_PDU_TYPE_IS_S(pdu) \
	64	(((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)
	65
	66	/* U-format PDU control field masks */
	67	#define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */
	68	#define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
	69	#define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)
	70
	71	#define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */
	72	#define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
	73	#define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
	74
	75	#define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */
	76	#define LLC_1_PDU_CMD_XID 0xAC
	77	#define LLC_1_PDU_CMD_TEST 0xE0
	78
	79	#define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */
80	#define LLC_2_PDU_CMD_DISC 0x40
81	#define LLC_2_PDU_RSP_UA 0x60
82	#define LLC_2_PDU_RSP_DM 0x0C
83	#define LLC_2_PDU_RSP_FRMR 0x84
84
85	/* Type 1 operations */
86
87	/* XID information field bit masks */
88
89	/* LLC format identifier (byte 1) */
90	#define LLC_XID_FMT_ID 0x81 /* first byte must be this */
91
92	/* LLC types/classes identifier (byte 2) */
93	#define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */
94	#define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */
95
96	#define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */
97	#define LLC_XID_NULL_CLASS_2 0x03
98	#define LLC_XID_NULL_CLASS_3 0x05
99	#define LLC_XID_NULL_CLASS_4 0x07
100
101	#define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */
102	#define LLC_XID_NNULL_TYPE_2 0x02
103	#define LLC_XID_NNULL_TYPE_3 0x04
104	#define LLC_XID_NNULL_TYPE_1_2 0x03
105	#define LLC_XID_NNULL_TYPE_1_3 0x05
106	#define LLC_XID_NNULL_TYPE_2_3 0x06
107	#define LLC_XID_NNULL_ALL 0x07
108
109	/* Sender Receive Window (byte 3) */
110	#define LLC_XID_RW_MASK 0xFE /* AND with value to get below */
111
112	#define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */
113
114	/* Type 2 operations */
115
116	#define LLC_2_SEQ_NBR_MODULO ((u8) 128)
117
118	/* I-PDU masks ('ctrl' is I-PDU control word) */
119	#define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1)
120	#define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1)
121
122	#define LLC_I_PF_BIT_MASK 0x01
123
124	#define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
125	#define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)
126
127	/* S-PDU supervisory commands and responses */
128
129	#define LLC_S_PDU_CMD_MASK 0x0C
130	#define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
131	#define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
132
133	#define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */
134	#define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */
135	#define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */
136	#define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */
137	#define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */
138	#define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */
139
140	#define LLC_S_PF_BIT_MASK 0x01
141	#define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
142	#define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)
143
144	#define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1)
7e030963	145	#define PDU_GET_NEXT_Vr(sn) (((sn) + 1) & ~LLC_2_SEQ_NBR_MODULO)
1da177e4 LT	146
	147	/* FRMR information field macros */
	148
	149	#define FRMR_INFO_LENGTH 5 /* 5 bytes of information */
	150
	151	/*
	152	* info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
	153	* (if U-PDU) or word pointer to rejected PDU control field
	154	*/
	155	#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
	156	info->rej_pdu_ctrl = ((((u8 ) rej_ctrl) & \
	157	LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
	158	(u16)((u16 ) rej_ctrl) : \
	159	(((u16) ((u8 ) rej_ctrl)) & 0x00FF))
	160
	161	/*
	162	* Info is pointer to FRMR info field structure; 'vs' is a byte containing
	163	* send state variable value in low-order 7 bits (insure the lowest-order
	164	* bit remains zero (0))
	165	*/
	166	#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
	167	#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))
	168
	169	/*
	170	* Info is pointer to FRMR info field structure; 'cr' is a byte containing
	171	* the C/R bit value in the low-order bit
	172	*/
	173	#define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv \|= (((u8) cr) & 0x01))
	174
	175	/*
	176	* In the remaining five macros, 'info' is pointer to FRMR info field
	177	* structure; 'ind' is a byte containing the bit value to set in the
	178	* lowest-order bit)
	179	*/
	180	#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
	181	(info->ind_bits = ((info->ind_bits & 0xFE) \| (((u8) ind) & 0x01)))
	182
	183	#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
	184	(info->ind_bits = ( (info->ind_bits & 0xFD) \| (((u8) ind) & 0x02)))
	185
	186	#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
	187	(info->ind_bits = ( (info->ind_bits & 0xFB) \| (((u8) ind) & 0x04)))
	188
	189	#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
	190	(info->ind_bits = ( (info->ind_bits & 0xF7) \| (((u8) ind) & 0x08)))
	191
	192	#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
	193	(info->ind_bits = ( (info->ind_bits & 0xEF) \| (((u8) ind) & 0x10)))
	194
	195	/* Sequence-numbered PDU format (4 bytes in length) */
	196	struct llc_pdu_sn {
	197	u8 dsap;
	198	u8 ssap;
	199	u8 ctrl_1;
	200	u8 ctrl_2;
a10e1466	201	} __packed;
1da177e4 LT	202
	203	static inline struct llc_pdu_sn llc_pdu_sn_hdr(struct sk_buff skb)
	204	{
d56f90a7	205	return (struct llc_pdu_sn *)skb_network_header(skb);
1da177e4 LT	206	}
	207
	208	/* Un-numbered PDU format (3 bytes in length) */
	209	struct llc_pdu_un {
	210	u8 dsap;
	211	u8 ssap;
	212	u8 ctrl_1;
a10e1466	213	} __packed;
1da177e4 LT	214
	215	static inline struct llc_pdu_un llc_pdu_un_hdr(struct sk_buff skb)
	216	{
d56f90a7	217	return (struct llc_pdu_un *)skb_network_header(skb);
1da177e4 LT	218	}
1da177e4 LT	219
1da177e4 LT	220	/**
	221	* llc_pdu_header_init - initializes pdu header
	222	* @skb: input skb that header must be set into it.
	223	* @type: type of PDU (U, I or S).
	224	* @ssap: source sap.
	225	* @dsap: destination sap.
	226	* @cr: command/response bit (0 or 1).
	227	*
	228	* This function sets DSAP, SSAP and command/Response bit in LLC header.
	229	*/
	230	static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
	231	u8 ssap, u8 dsap, u8 cr)
	232	{
	233	const int hlen = type == LLC_PDU_TYPE_U ? 3 : 4;
37e66366 ACM	234	struct llc_pdu_un *pdu;
	235
	236	skb_push(skb, hlen);
c1d2bbe1	237	skb_reset_network_header(skb);
37e66366	238	pdu = llc_pdu_un_hdr(skb);
1da177e4 LT	239	pdu->dsap = dsap;
	240	pdu->ssap = ssap;
	241	pdu->ssap \|= cr;
	242	}
	243
	244	/**
	245	* llc_pdu_decode_sa - extracs source address (MAC) of input frame
	246	* @skb: input skb that source address must be extracted from it.
	247	* @sa: pointer to source address (6 byte array).
	248	*
	249	* This function extracts source address(MAC) of input frame.
	250	*/
	251	static inline void llc_pdu_decode_sa(struct sk_buff skb, u8 sa)
	252	{
3fbd418a	253	if (skb->protocol == htons(ETH_P_802_2))
1da177e4	254	memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
1da177e4 LT	255	}
	256
	257	/**
	258	* llc_pdu_decode_da - extracts dest address of input frame
	259	* @skb: input skb that destination address must be extracted from it
	260	* @sa: pointer to destination address (6 byte array).
	261	*
	262	* This function extracts destination address(MAC) of input frame.
	263	*/
	264	static inline void llc_pdu_decode_da(struct sk_buff skb, u8 da)
	265	{
3fbd418a	266	if (skb->protocol == htons(ETH_P_802_2))
1da177e4	267	memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
1da177e4 LT	268	}
	269
	270	/**
	271	* llc_pdu_decode_ssap - extracts source SAP of input frame
	272	* @skb: input skb that source SAP must be extracted from it.
	273	* @ssap: source SAP (output argument).
	274	*
	275	* This function extracts source SAP of input frame. Right bit of SSAP is
	276	* command/response bit.
	277	*/
	278	static inline void llc_pdu_decode_ssap(struct sk_buff skb, u8 ssap)
	279	{
	280	*ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
	281	}
	282
	283	/**
	284	* llc_pdu_decode_dsap - extracts dest SAP of input frame
	285	* @skb: input skb that destination SAP must be extracted from it.
	286	* @dsap: destination SAP (output argument).
	287	*
	288	* This function extracts destination SAP of input frame. right bit of
	289	* DSAP designates individual/group SAP.
	290	*/
	291	static inline void llc_pdu_decode_dsap(struct sk_buff skb, u8 dsap)
	292	{
	293	*dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
	294	}
	295
	296	/**
	297	* llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
	298	* @skb: input skb that header must be set into it.
	299	*
	300	* This function sets third byte of LLC header as a UI PDU.
	301	*/
	302	static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
	303	{
	304	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	305
	306	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	307	pdu->ctrl_1 \|= LLC_1_PDU_CMD_UI;
	308	}
	309
	310	/**
	311	* llc_pdu_init_as_test_cmd - sets PDU as TEST
	312	* @skb - Address of the skb to build
	313	*
	314	* Sets a PDU as TEST
	315	*/
	316	static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
	317	{
	318	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	319
	320	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	321	pdu->ctrl_1 \|= LLC_1_PDU_CMD_TEST;
	322	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	323	}
	324
	325	/**
	326	* llc_pdu_init_as_test_rsp - build TEST response PDU
	327	* @skb: Address of the skb to build
	328	* @ev_skb: The received TEST command PDU frame
	329	*
	330	* Builds a pdu frame as a TEST response.
	331	*/
332	static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
333	struct sk_buff *ev_skb)
334	{
335	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
336
337	pdu->ctrl_1 = LLC_PDU_TYPE_U;
338	pdu->ctrl_1 \|= LLC_1_PDU_CMD_TEST;
339	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
3fbd418a	340	if (ev_skb->protocol == htons(ETH_P_802_2)) {
1da177e4 LT	341	struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
	342	int dsize;
	343
	344	dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
	345	memcpy(((u8 )pdu) + 3, ((u8 )ev_pdu) + 3, dsize);
	346	skb_put(skb, dsize);
	347	}
	348	}
	349
	350	/* LLC Type 1 XID command/response information fields format */
	351	struct llc_xid_info {
cf225356	352	u8 fmt_id; /* always 0x81 for LLC */
1da177e4 LT	353	u8 type; /* different if NULL/non-NULL LSAP */
1da177e4 LT	354	u8 rw; /* sender receive window */
a10e1466	355	} __packed;
1da177e4 LT	356
	357	/**
	358	* llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
	359	* @skb: input skb that header must be set into it.
	360	*
	361	* This function sets third,fourth,fifth and sixth bytes of LLC header as
	362	* a XID PDU.
	363	*/
	364	static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
	365	u8 svcs_supported, u8 rx_window)
	366	{
	367	struct llc_xid_info *xid_info;
	368	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	369
	370	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	371	pdu->ctrl_1 \|= LLC_1_PDU_CMD_XID;
	372	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	373	xid_info = (struct llc_xid_info )(((u8 )&pdu->ctrl_1) + 1);
	374	xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */
	375	xid_info->type = svcs_supported;
	376	xid_info->rw = rx_window << 1; /* size of receive window */
f83f1768	377	skb_put(skb, sizeof(struct llc_xid_info));
1da177e4 LT	378	}
	379
	380	/**
	381	* llc_pdu_init_as_xid_rsp - builds XID response PDU
	382	* @skb: Address of the skb to build
	383	* @svcs_supported: The class of the LLC (I or II)
	384	* @rx_window: The size of the receive window of the LLC
	385	*
	386	* Builds a pdu frame as an XID response.
	387	*/
	388	static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
	389	u8 svcs_supported, u8 rx_window)
	390	{
	391	struct llc_xid_info *xid_info;
	392	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	393
	394	pdu->ctrl_1 = LLC_PDU_TYPE_U;
	395	pdu->ctrl_1 \|= LLC_1_PDU_CMD_XID;
	396	pdu->ctrl_1 \|= LLC_U_PF_BIT_MASK;
	397
	398	xid_info = (struct llc_xid_info )(((u8 )&pdu->ctrl_1) + 1);
	399	xid_info->fmt_id = LLC_XID_FMT_ID;
	400	xid_info->type = svcs_supported;
	401	xid_info->rw = rx_window << 1;
f83f1768	402	skb_put(skb, sizeof(struct llc_xid_info));
1da177e4 LT	403	}
	404
	405	/* LLC Type 2 FRMR response information field format */
	406	struct llc_frmr_info {
	407	u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */
	408	u8 curr_ssv; /* current send state variable val */
	409	u8 curr_rsv; /* current receive state variable */
	410	u8 ind_bits; /* indicator bits set with macro */
a10e1466	411	} __packed;
1da177e4	412
bf3c710f JP	413	void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
	414	void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
	415	void llc_pdu_decode_pf_bit(struct sk_buff skb, u8 pf_bit);
	416	void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
	417	void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
	418	void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	419	void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	420	void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
	421	void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
	422	void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
	423	void llc_pdu_init_as_frmr_rsp(struct sk_buff skb, struct llc_pdu_sn prev_pdu,
	424	u8 f_bit, u8 vs, u8 vr, u8 vzyxw);
	425	void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	426	void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	427	void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
	428	void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
1da177e4	429	#endif /* LLC_PDU_H */