include/net/lapb.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _LAPB_H
0003 #define _LAPB_H
0004 #include <linux/lapb.h>
0005 #include <linux/refcount.h>
0006
0007 #define LAPB_HEADER_LEN 20      /* LAPB over Ethernet + a bit more */
0008
0009 #define LAPB_ACK_PENDING_CONDITION  0x01
0010 #define LAPB_REJECT_CONDITION       0x02
0011 #define LAPB_PEER_RX_BUSY_CONDITION 0x04
0012
0013 /* Control field templates */
0014 #define LAPB_I      0x00    /* Information frames */
0015 #define LAPB_S      0x01    /* Supervisory frames */
0016 #define LAPB_U      0x03    /* Unnumbered frames */
0017
0018 #define LAPB_RR     0x01    /* Receiver ready */
0019 #define LAPB_RNR    0x05    /* Receiver not ready */
0020 #define LAPB_REJ    0x09    /* Reject */
0021
0022 #define LAPB_SABM   0x2F    /* Set Asynchronous Balanced Mode */
0023 #define LAPB_SABME  0x6F    /* Set Asynchronous Balanced Mode Extended */
0024 #define LAPB_DISC   0x43    /* Disconnect */
0025 #define LAPB_DM     0x0F    /* Disconnected mode */
0026 #define LAPB_UA     0x63    /* Unnumbered acknowledge */
0027 #define LAPB_FRMR   0x87    /* Frame reject */
0028
0029 #define LAPB_ILLEGAL    0x100   /* Impossible to be a real frame type */
0030
0031 #define LAPB_SPF    0x10    /* Poll/final bit for standard LAPB */
0032 #define LAPB_EPF    0x01    /* Poll/final bit for extended LAPB */
0033
0034 #define LAPB_FRMR_W 0x01    /* Control field invalid    */
0035 #define LAPB_FRMR_X 0x02    /* I field invalid      */
0036 #define LAPB_FRMR_Y 0x04    /* I field too long     */
0037 #define LAPB_FRMR_Z 0x08    /* Invalid N(R)         */
0038
0039 #define LAPB_POLLOFF    0
0040 #define LAPB_POLLON 1
0041
0042 /* LAPB C-bit */
0043 #define LAPB_COMMAND    1
0044 #define LAPB_RESPONSE   2
0045
0046 #define LAPB_ADDR_A 0x03
0047 #define LAPB_ADDR_B 0x01
0048 #define LAPB_ADDR_C 0x0F
0049 #define LAPB_ADDR_D 0x07
0050
0051 /* Define Link State constants. */
0052 enum {
0053     LAPB_STATE_0,   /* Disconnected State       */
0054     LAPB_STATE_1,   /* Awaiting Connection State    */
0055     LAPB_STATE_2,   /* Awaiting Disconnection State */
0056     LAPB_STATE_3,   /* Data Transfer State      */
0057     LAPB_STATE_4    /* Frame Reject State       */
0058 };
0059
0060 #define LAPB_DEFAULT_MODE       (LAPB_STANDARD | LAPB_SLP | LAPB_DTE)
0061 #define LAPB_DEFAULT_WINDOW     7       /* Window=7 */
0062 #define LAPB_DEFAULT_T1         (5 * HZ)    /* T1=5s    */
0063 #define LAPB_DEFAULT_T2         (1 * HZ)    /* T2=1s    */
0064 #define LAPB_DEFAULT_N2         20      /* N2=20    */
0065
0066 #define LAPB_SMODULUS   8
0067 #define LAPB_EMODULUS   128
0068
0069 /*
0070  *  Information about the current frame.
0071  */
0072 struct lapb_frame {
0073     unsigned short      type;       /* Parsed type      */
0074     unsigned short      nr, ns;     /* N(R), N(S)       */
0075     unsigned char       cr;     /* Command/Response */
0076     unsigned char       pf;     /* Poll/Final       */
0077     unsigned char       control[2]; /* Original control data*/
0078 };
0079
0080 /*
0081  *  The per LAPB connection control structure.
0082  */
0083 struct lapb_cb {
0084     struct list_head    node;
0085     struct net_device   *dev;
0086
0087     /* Link status fields */
0088     unsigned int        mode;
0089     unsigned char       state;
0090     unsigned short      vs, vr, va;
0091     unsigned char       condition;
0092     unsigned short      n2, n2count;
0093     unsigned short      t1, t2;
0094     struct timer_list   t1timer, t2timer;
0095     bool            t1timer_running, t2timer_running;
0096
0097     /* Internal control information */
0098     struct sk_buff_head write_queue;
0099     struct sk_buff_head ack_queue;
0100     unsigned char       window;
0101     const struct lapb_register_struct *callbacks;
0102
0103     /* FRMR control information */
0104     struct lapb_frame   frmr_data;
0105     unsigned char       frmr_type;
0106
0107     spinlock_t      lock;
0108     refcount_t      refcnt;
0109 };
0110
0111 /* lapb_iface.c */
0112 void lapb_connect_confirmation(struct lapb_cb *lapb, int);
0113 void lapb_connect_indication(struct lapb_cb *lapb, int);
0114 void lapb_disconnect_confirmation(struct lapb_cb *lapb, int);
0115 void lapb_disconnect_indication(struct lapb_cb *lapb, int);
0116 int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *);
0117 int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *);
0118
0119 /* lapb_in.c */
0120 void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *);
0121
0122 /* lapb_out.c */
0123 void lapb_kick(struct lapb_cb *lapb);
0124 void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *, int);
0125 void lapb_establish_data_link(struct lapb_cb *lapb);
0126 void lapb_enquiry_response(struct lapb_cb *lapb);
0127 void lapb_timeout_response(struct lapb_cb *lapb);
0128 void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short);
0129 void lapb_check_need_response(struct lapb_cb *lapb, int, int);
0130
0131 /* lapb_subr.c */
0132 void lapb_clear_queues(struct lapb_cb *lapb);
0133 void lapb_frames_acked(struct lapb_cb *lapb, unsigned short);
0134 void lapb_requeue_frames(struct lapb_cb *lapb);
0135 int lapb_validate_nr(struct lapb_cb *lapb, unsigned short);
0136 int lapb_decode(struct lapb_cb *lapb, struct sk_buff *, struct lapb_frame *);
0137 void lapb_send_control(struct lapb_cb *lapb, int, int, int);
0138 void lapb_transmit_frmr(struct lapb_cb *lapb);
0139
0140 /* lapb_timer.c */
0141 void lapb_start_t1timer(struct lapb_cb *lapb);
0142 void lapb_start_t2timer(struct lapb_cb *lapb);
0143 void lapb_stop_t1timer(struct lapb_cb *lapb);
0144 void lapb_stop_t2timer(struct lapb_cb *lapb);
0145 int lapb_t1timer_running(struct lapb_cb *lapb);
0146
0147 /*
0148  * Debug levels.
0149  *  0 = Off
0150  *  1 = State Changes
0151  *  2 = Packets I/O and State Changes
0152  *  3 = Hex dumps, Packets I/O and State Changes.
0153  */
0154 #define LAPB_DEBUG  0
0155
0156 #define lapb_dbg(level, fmt, ...)           \
0157 do {                            \
0158     if (level < LAPB_DEBUG)             \
0159         pr_debug(fmt, ##__VA_ARGS__);       \
0160 } while (0)
0161
0162 #endif