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/*----
// hdlc.h
6-18-97 change timing on timeouts to 1.0 sec base.------*/
#define HDLC_TRACE_outs(c)
#define HDLC_DEB_outs(s,l)
// define a circular queue for incoming packets.
// queue uses an extra tail end head room of MAX_PKT_SIZE to avoid having to
// perform to much sypherin concerning queue room.
#define HDLC_TX_PKT_QUEUE_SIZE 9
// control fields for hdlc header control field
#define CONTROL_IFRAME 0
#define CONTROL_UFRAME 1
#define CONTROL_CONNECT_ASK 3
#define CONTROL_CONNECT_REPLY 5
/*--------------------------------------------
Hdlc struct - main struct for HDLC support(layer 2)----------------------------------------------*/typedef struct { //LanPort *lp; // our layer 1 handle.
Nic *nic; // nic card we are bound to on lower end
PVOID context; // upper layer can put handle here
BYTE dest_addr[6]; // dest. address(needed for ack/seq. timeouts)
WORD phys_outpkt_len[HDLC_TX_PKT_QUEUE_SIZE]; //----- circular que of outgoing data packets
Queue qout;
// packet and buffer pool handles, basically points to the
// tx-buffer space in qout.
NDIS_HANDLE TxPacketPool; NDIS_HANDLE TxBufferPool; // queue of packets setup for use
PNDIS_PACKET TxPackets[HDLC_TX_PKT_QUEUE_SIZE];
// control packet and buffer pool handles, basically points to the
// tx-buffer space in qout_ctl.
NDIS_HANDLE TxCtlPacketPool; NDIS_HANDLE TxCtlBufferPool; // queue of packets setup for use
PNDIS_PACKET TxCtlPackets[2]; //----- circular que of outgoing control packets
Queue qout_ctl;
//----- timer statistics
DWORD rec_ack_timeouts; // # of rec-ack-timeouts
DWORD send_ack_timeouts; // # of send-ack-timeouts
//----- outgoing statistics
DWORD iframes_resent; // cout of all resent iframes
DWORD iframes_sent; // count of every sent iframe
DWORD ctlframes_sent; // count of every sent control frame
DWORD rawframes_sent; // count of every sent raw frame
DWORD iframes_outofseq; // statistics, error count
//DWORD ErrBadHeader; // statistics, error count
//----- incoming statistics
DWORD frames_rcvd; //
//------ packet driver handle
WORD status;
// sent out on each packet, increment by one each time a new packet
// is sent out. The receiver uses this to check for packet sequence
// order. This value is copied into the snd_index field when we are
// ready to send a packet. A sync-message will set this to an
// initial working value of 0.
BYTE out_snd_index;
// last good rx ack_index received. The receiver will send us a
// acknowledge index(ack_index field) indicating the last good
// received packet index it received. This allows us to remove
// all packets up to this index number from our transmit buffer
// since they have been acknowledged. Until this point we must
// retain the packet for retransmition in case the receiver does
// not acknowledge reception after a timeout period.
BYTE in_ack_index;
// last good rx snd_index on received packet. All packets received
// should have a snd_index value equal to +1 of this value. So this
// value is used to check for consequative incrementing index values
// on the packets received. On sync-message this value is set to
// 0xff.
BYTE next_in_index;
// used to measure how many incoming pkts received which are
// unacknowledged so we can trip a acknowledgement at 80% full
BYTE unacked_pkts;
// tick counter used to timeout sent packets and the expected
// acknowledgement.
WORD sender_ack_timer;
// tick counters used to check that connection is still active
// periodically to recover from device power-cycle or hdlc
// sequence level failure. If it ticks up past X many minutes
// then a iframe packet is sent(and a iframe response is expected
// back. If it ticks past (X*2) minutes, then failure is declared
// and server re-initializes the box.
WORD tx_alive_timer; // ticks up, reset every acked-reclaim of sent iframe.
WORD rx_alive_timer; // ticks up, reset on every received iframe.
WORD tick_timer; // used to generate 10Hz timer signal used for timeouts.
// tick counter used to timeout rec. packets and our responsibility
// to send and ack on them
WORD rec_ack_timer;
WORD pkt_window_size; // 1 to 8, num tx packets before ack
WORD state; // state of hdlc level, see defines
WORD old_state; // old state of hdlc level(used to reset timer)
WORD sub_state; // sub_state of a particular state
WORD state_timer; // state timer
// following function ptrs is a general method for linking
// layers together.
ULONG (*upper_layer_proc) (PVOID context, int message_id, ULONG message_data); ULONG (*lower_layer_proc) (PVOID context, int message_id, ULONG message_data);} Hdlc;
//--- layer 2 HDLC events used in _proc() calls
// layer 2(hdlc) assigned range from 200-299
#define EV_L2_RESYNC 200
#define EV_L2_RX_PACKET 201
#define EV_L2_TX_PACKET 202
#define EV_L2_BOOT_REPLY 203
#define EV_L2_ADMIN_REPLY 204
#define EV_L2_RELOAD 205
#define EV_L2_CHECK_LINK 206
// packet sequence timeout values
#define MIN_ACK_REC_TIME 10 // 10th seconds (1.0 sec)
#define KEEP_ALIVE_TIMEOUT 300 // 10th seconds (30.0 sec)
// state field defines
//#define ST_HDLC_OFF 0 // HDLC is off, won't do anything.
//#define ST_HDLC_DISCONNECTED 1 // HDLC is turned on, will allow connections
//#define ST_HDLC_CONNECTED 2 // HDLC is connected up and active
// status field bit values
#define LST_RESYNC 0x0001 // set if we need to re-sync the packet index
// #define LST_SEND_NAK 0x0002 // set if we need to update other side with index
#define LST_RECLAIM 0x0004 // set if we should attempt to reclaim tx packets
#define LST_SEND_ACK 0x0008 // set if we need to send immediate ACK
//------------------ public functions
int hdlc_open(Hdlc *hd, BYTE *box_mac_addr);int hdlc_close(Hdlc *hd);
#define ERR_GET_EMPTY 1 // empty
#define ERR_GET_BAD_INDEX 2 // error, packet out of sequence
#define ERR_GET_BADHDR 3 // error, not our packet
#define ERR_CONTROL_PACKET 4 // hdlc control packet only, no data
int hdlc_validate_rx_pkt(Hdlc *hd, BYTE *buf);
int hdlc_send_outpkt(Hdlc *hd, int data_len, BYTE *dest_addr);int hdlc_send_ctl_outpkt(Hdlc *hd, int data_len, BYTE *dest_addr);
int hdlc_get_outpkt(Hdlc *hd, BYTE **buf);int hdlc_get_ctl_outpkt(Hdlc *hd, BYTE **buf);
int hdlc_send_raw(Hdlc *hd, int data_len, BYTE *dest_addr);int hdlc_resend_outpkt(Hdlc *hd);void hdlc_resync(Hdlc *hd);void hdlc_poll(Hdlc *hd);int hdlc_close(Hdlc *hd);
int hdlc_send_control(Hdlc *hd, BYTE *header_data, int header_len, BYTE *data, int data_len, BYTE *dest_addr);
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