lapb.h

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#ifndef _LAPB_H
#define _LAPB_H 
#include <linux/lapb.h>

#define LAPB_HEADER_LEN 20      /* LAPB over Ethernet + a bit more */

#define LAPB_ACK_PENDING_CONDITION  0x01
#define LAPB_REJECT_CONDITION       0x02
#define LAPB_PEER_RX_BUSY_CONDITION 0x04

/* Control field templates */
#define LAPB_I      0x00    /* Information frames */
#define LAPB_S      0x01    /* Supervisory frames */
#define LAPB_U      0x03    /* Unnumbered frames */

#define LAPB_RR     0x01    /* Receiver ready */
#define LAPB_RNR    0x05    /* Receiver not ready */
#define LAPB_REJ    0x09    /* Reject */

#define LAPB_SABM   0x2F    /* Set Asynchronous Balanced Mode */
#define LAPB_SABME  0x6F    /* Set Asynchronous Balanced Mode Extended */
#define LAPB_DISC   0x43    /* Disconnect */
#define LAPB_DM     0x0F    /* Disconnected mode */
#define LAPB_UA     0x63    /* Unnumbered acknowledge */
#define LAPB_FRMR   0x87    /* Frame reject */

#define LAPB_ILLEGAL    0x100   /* Impossible to be a real frame type */

#define LAPB_SPF    0x10    /* Poll/final bit for standard LAPB */
#define LAPB_EPF    0x01    /* Poll/final bit for extended LAPB */

#define LAPB_FRMR_W 0x01    /* Control field invalid    */
#define LAPB_FRMR_X 0x02    /* I field invalid      */
#define LAPB_FRMR_Y 0x04    /* I field too long     */
#define LAPB_FRMR_Z 0x08    /* Invalid N(R)         */

#define LAPB_POLLOFF    0
#define LAPB_POLLON 1

/* LAPB C-bit */
#define LAPB_COMMAND    1
#define LAPB_RESPONSE   2

#define LAPB_ADDR_A 0x03
#define LAPB_ADDR_B 0x01
#define LAPB_ADDR_C 0x0F
#define LAPB_ADDR_D 0x07

/* Define Link State constants. */
enum {
    LAPB_STATE_0,   /* Disconnected State       */
    LAPB_STATE_1,   /* Awaiting Connection State    */
    LAPB_STATE_2,   /* Awaiting Disconnection State */
    LAPB_STATE_3,   /* Data Transfer State      */
    LAPB_STATE_4    /* Frame Reject State       */
};

#define LAPB_DEFAULT_MODE       (LAPB_STANDARD | LAPB_SLP | LAPB_DTE)
#define LAPB_DEFAULT_WINDOW     7       /* Window=7 */
#define LAPB_DEFAULT_T1         (5 * HZ)    /* T1=5s    */
#define LAPB_DEFAULT_T2         (1 * HZ)    /* T2=1s    */
#define LAPB_DEFAULT_N2         20      /* N2=20    */

#define LAPB_SMODULUS   8
#define LAPB_EMODULUS   128

/*
 *  Information about the current frame.
 */
struct lapb_frame {
    unsigned short      type;       /* Parsed type      */
    unsigned short      nr, ns;     /* N(R), N(S)       */
    unsigned char       cr;     /* Command/Response */
    unsigned char       pf;     /* Poll/Final       */
    unsigned char       control[2]; /* Original control data*/
};

/*
 *  The per LAPB connection control structure.
 */
struct lapb_cb {
    struct list_head    node;
    struct net_device   *dev;

    /* Link status fields */
    unsigned int        mode;
    unsigned char       state;
    unsigned short      vs, vr, va;
    unsigned char       condition;
    unsigned short      n2, n2count;
    unsigned short      t1, t2;
    struct timer_list   t1timer, t2timer;

    /* Internal control information */
    struct sk_buff_head write_queue;
    struct sk_buff_head ack_queue;
    unsigned char       window;
    const struct lapb_register_struct *callbacks;

    /* FRMR control information */
    struct lapb_frame   frmr_data;
    unsigned char       frmr_type;

    atomic_t        refcnt;
};

/* lapb_iface.c */
extern void lapb_connect_confirmation(struct lapb_cb *lapb, int);
extern void lapb_connect_indication(struct lapb_cb *lapb, int);
extern void lapb_disconnect_confirmation(struct lapb_cb *lapb, int);
extern void lapb_disconnect_indication(struct lapb_cb *lapb, int);
extern int  lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *);
extern int  lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *);

/* lapb_in.c */
extern void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *);

/* lapb_out.c */
extern void lapb_kick(struct lapb_cb *lapb);
extern void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *, int);
extern void lapb_establish_data_link(struct lapb_cb *lapb);
extern void lapb_enquiry_response(struct lapb_cb *lapb);
extern void lapb_timeout_response(struct lapb_cb *lapb);
extern void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short);
extern void lapb_check_need_response(struct lapb_cb *lapb, int, int);

/* lapb_subr.c */
extern void lapb_clear_queues(struct lapb_cb *lapb);
extern void lapb_frames_acked(struct lapb_cb *lapb, unsigned short);
extern void lapb_requeue_frames(struct lapb_cb *lapb);
extern int  lapb_validate_nr(struct lapb_cb *lapb, unsigned short);
extern int lapb_decode(struct lapb_cb *lapb, struct sk_buff *, struct lapb_frame *);
extern void lapb_send_control(struct lapb_cb *lapb, int, int, int);
extern void lapb_transmit_frmr(struct lapb_cb *lapb);

/* lapb_timer.c */
extern void lapb_start_t1timer(struct lapb_cb *lapb);
extern void lapb_start_t2timer(struct lapb_cb *lapb);
extern void lapb_stop_t1timer(struct lapb_cb *lapb);
extern void lapb_stop_t2timer(struct lapb_cb *lapb);
extern int  lapb_t1timer_running(struct lapb_cb *lapb);

/*
 * Debug levels.
 *  0 = Off
 *  1 = State Changes
 *  2 = Packets I/O and State Changes
 *  3 = Hex dumps, Packets I/O and State Changes.
 */
#define LAPB_DEBUG  0

#define lapb_dbg(level, fmt, ...)           \
do {                            \
    if (level < LAPB_DEBUG)             \
        pr_debug(fmt, ##__VA_ARGS__);       \
} while (0)

#endif