diff options
Diffstat (limited to 'tools/ubcsp.c')
| -rw-r--r-- | tools/ubcsp.c | 1180 |
1 files changed, 1180 insertions, 0 deletions
diff --git a/tools/ubcsp.c b/tools/ubcsp.c new file mode 100644 index 0000000..93b8c0f --- /dev/null +++ b/tools/ubcsp.c @@ -0,0 +1,1180 @@ +/*
+ *
+ * BlueZ - Bluetooth protocol stack for Linux
+ *
+ * Copyright (C) 2000-2005 CSR Ltd.
+ *
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+/*****************************************************************************/
+/*****************************************************************************/
+/*****************************************************************************/
+/** **/
+/** ubcsp,c **/
+/** **/
+/** MicroBCSP - a very low cost implementation of the BCSP protocol **/
+/** **/
+/*****************************************************************************/
+
+#include "ubcsp.h"
+
+#if SHOW_PACKET_ERRORS || SHOW_LE_STATES
+#include <stdio.h>
+#include <windows.h>
+#endif
+
+static uint16 ubcsp_calc_crc (uint8 ch, uint16 crc);
+static uint16 ubcsp_crc_reverse (uint16);
+
+/*****************************************************************************/
+/** **/
+/** Constant Data - ROM **/
+/** **/
+/*****************************************************************************/
+
+/* This is the storage for the link establishment messages */
+
+static const uint8 ubcsp_le_buffer[4][4] =
+ {
+ { 0xDA, 0xDC, 0xED, 0xED },
+ { 0xAC, 0xAF, 0xEF, 0xEE },
+ { 0xAD, 0xEF, 0xAC, 0xED },
+ { 0xDE, 0xAD, 0xD0, 0xD0 },
+ };
+
+/* These are the link establishment headers */
+/* The two version are for the CRC and non-CRC varients */
+
+#if UBCSP_CRC
+static const uint8 ubcsp_send_le_header[4] =
+ {
+ 0x40, 0x41, 0x00, 0x7E
+ };
+#else
+static const uint8 ubcsp_send_le_header[4] =
+ {
+ 0x00, 0x41, 0x00, 0xBE
+ };
+#endif
+
+/*****************************************************************************/
+/** **/
+/** Static Data - RAM **/
+/** **/
+/*****************************************************************************/
+
+/* This is the storage for all state data for ubcsp */
+
+static struct ubcsp_configuration ubcsp_config;
+
+/* This is the ACK packet header - this will be overwritten when
+ we create an ack packet */
+
+static uint8 ubcsp_send_ack_header[4] =
+ {
+ 0x00, 0x00, 0x00, 0x00
+ };
+
+/* This is the deslip lookup table */
+
+static const uint8 ubcsp_deslip[2] =
+ {
+ SLIP_FRAME, SLIP_ESCAPE,
+ };
+
+/* This is a state machine table for link establishment */
+
+static uint8 next_le_packet[16] =
+ {
+ ubcsp_le_sync, // uninit
+ ubcsp_le_conf, // init
+ ubcsp_le_none, // active
+ ubcsp_le_none,
+ ubcsp_le_sync_resp, // sync_resp
+ ubcsp_le_sync_resp,
+ ubcsp_le_none,
+ ubcsp_le_none,
+ ubcsp_le_none, // conf_resp
+ ubcsp_le_conf_resp,
+ ubcsp_le_conf_resp,
+ ubcsp_le_none,
+ };
+
+/* This is the storage required for building send and crc data */
+
+static uint8 ubcsp_send_header[4];
+static uint8 ubcsp_send_crc[2];
+
+/* This is where the receive header is stored before the payload arrives */
+
+static uint8 ubcsp_receive_header[4];
+
+/*****************************************************************************/
+/** **/
+/** Code - ROM or RAM **/
+/** **/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_initialize **/
+/** **/
+/** This initializes the state of the ubcsp engine to a known values **/
+/** **/
+/*****************************************************************************/
+
+void ubcsp_initialize (void)
+{
+ ubcsp_config.ack_number = 0;
+ ubcsp_config.sequence_number = 0;
+ ubcsp_config.send_ptr = 0;
+ ubcsp_config.send_size = 0;
+ ubcsp_config.receive_index = -4;
+
+ ubcsp_config.delay = 0;
+
+#if SHOW_LE_STATES
+ printf ("Hello Link Uninitialized\n");
+#endif
+
+ ubcsp_config.link_establishment_state = ubcsp_le_uninitialized;
+ ubcsp_config.link_establishment_packet = ubcsp_le_sync;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_send_packet **/
+/** **/
+/** This sends a packet structure for sending to the ubcsp engine **/
+/** This can only be called when the activity indication from ubcsp_poll **/
+/** indicates that a packet can be sent with UBCSP_PACKET_SENT **/
+/** **/
+/*****************************************************************************/
+
+void ubcsp_send_packet (struct ubcsp_packet *send_packet)
+{
+ /* Initialize the send data to the packet we want to send */
+
+ ubcsp_config.send_packet = send_packet;
+
+ /* we cannot send the packet at the moment
+ when we can at the moment, just set things to 0 */
+
+ ubcsp_config.send_size = 0;
+ ubcsp_config.send_ptr = 0;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_receive_packet **/
+/** **/
+/** This sends a packet structure for receiving to the ubcsp engine **/
+/** This can only be called when the activity indication from ubcsp_poll **/
+/** indicates that a packet can be sent with UBCSP_PACKET_RECEIVED **/
+/** **/
+/*****************************************************************************/
+
+void ubcsp_receive_packet (struct ubcsp_packet *receive_packet)
+{
+ /* Initialize the receive data to the packet we want to receive */
+
+ ubcsp_config.receive_packet = receive_packet;
+
+ /* setup to receive the header first */
+
+ ubcsp_config.receive_index = -4;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_calc_crc **/
+/** **/
+/** Takes the next 8 bit value ch, and updates the crc with this value **/
+/** **/
+/*****************************************************************************/
+
+
+#ifdef UBCSP_CRC
+
+static uint16 ubcsp_calc_crc (uint8 ch, uint16 crc)
+{
+ /* Calculate the CRC using the above 16 entry lookup table */
+
+ static const uint16 crc_table[] =
+ {
+ 0x0000, 0x1081, 0x2102, 0x3183,
+ 0x4204, 0x5285, 0x6306, 0x7387,
+ 0x8408, 0x9489, 0xa50a, 0xb58b,
+ 0xc60c, 0xd68d, 0xe70e, 0xf78f
+ };
+
+ /* Do this four bits at a time - more code, less space */
+
+ crc = (crc >> 4) ^ crc_table[(crc ^ ch) & 0x000f];
+ crc = (crc >> 4) ^ crc_table[(crc ^ (ch >> 4)) & 0x000f];
+
+ return crc;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_crc_reverse **/
+/** **/
+/** Reserves the bits in crc and returns the new value **/
+/** **/
+/*****************************************************************************/
+
+static uint16 ubcsp_crc_reverse (uint16 crc)
+{
+ int32
+ b,
+ rev;
+
+ /* Reserse the bits to compute the actual CRC value */
+
+ for (b = 0, rev=0; b < 16; b++)
+ {
+ rev = rev << 1;
+ rev |= (crc & 1);
+ crc = crc >> 1;
+ }
+
+ return rev;
+}
+
+#endif
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_put_slip_uart **/
+/** **/
+/** Outputs a single octet to the uart **/
+/** If the octet needs to be escaped, then output the escape value **/
+/** and then store the second octet to be output later **/
+/** **/
+/*****************************************************************************/
+
+static void ubcsp_put_slip_uart (uint8 ch)
+{
+ /* output a single UART octet */
+
+ /* If it needs to be escaped, then output the escape octet
+ and set the send_slip_escape so that the next time we
+ output the second octet for the escape correctly.
+ This is done right at the top of ubcsp_poll */
+
+ if (ch == SLIP_FRAME)
+ {
+ put_uart (SLIP_ESCAPE);
+ ubcsp_config.send_slip_escape = SLIP_ESCAPE_FRAME;
+ }
+ else if (ch == SLIP_ESCAPE)
+ {
+ put_uart (SLIP_ESCAPE);
+ ubcsp_config.send_slip_escape = SLIP_ESCAPE_ESCAPE;
+ }
+ else
+ {
+ /* Not escaped, so just output octet */
+
+ put_uart (ch);
+ }
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_which_le_payload **/
+/** **/
+/** Check the payload of this packet, and determine which of the four **/
+/** link establishment packets this was. **/
+/** Can return 5 if it is not a valid link establishment packet **/
+/** **/
+/*****************************************************************************/
+
+static uint32 ubcsp_which_le_payload (const uint8 *payload)
+{
+ static int32
+ octet,
+ loop;
+
+ /* Search through the various link establishment payloads to find
+ which one we have received */
+
+ for (loop = 0; loop < 4; loop ++)
+ {
+ for (octet = 0; octet < 4; octet ++)
+ {
+ if (payload[octet] != ubcsp_le_buffer[loop][octet])
+ {
+ /* Bad match, just to loop again */
+ goto bad_match_loop;
+ }
+ }
+
+ /* All the octets matched, return the value */
+
+ return loop;
+
+ /* Jumps out of octet loop if we got a bad match */
+bad_match_loop:
+ {}
+ }
+
+ /* Non of the link establishment payloads matched - return invalid value */
+
+ return 5;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_recevied_packet **/
+/** **/
+/** This function is called when we have a SLIP END octet and a full **/
+/** packet header and possibly data in the receive packet **/
+/** **/
+/*****************************************************************************/
+
+static uint8 ubcsp_recevied_packet (void)
+{
+ static uint8
+ receive_crc,
+ receive_seq,
+ receive_ack,
+ activity;
+
+#if UBCSP_CRC
+ static int32
+ loop;
+
+ static uint16
+ crc;
+#endif
+
+ static uint16
+ length;
+
+ /* Keep track of what activity this received packet will cause */
+
+ activity = 0;
+
+ /*** Do all error checks that we can ***/
+
+ /* First check the header checksum */
+
+ if (((ubcsp_receive_header[0] + ubcsp_receive_header[1] + ubcsp_receive_header[2] + ubcsp_receive_header[3]) & 0xff) != 0xff)
+ {
+ /* Header Checksum Error */
+
+#if SHOW_PACKET_ERRORS
+ printf ("\n######################## Header Checksum Error %02X %02X %02X %02X\n",
+ ubcsp_receive_header[0],
+ ubcsp_receive_header[1],
+ ubcsp_receive_header[2],
+ ubcsp_receive_header[3]);
+#endif
+
+ /* If we have a header checksum error, send an ack in return
+ this gets a packet to be resent as quickly as possible */
+
+ ubcsp_config.send_ack = 1;
+
+ return activity;
+ }
+
+ /* Decode the received packets header */
+
+ ubcsp_config.receive_packet->reliable = (ubcsp_receive_header[0] & 0x80) >> 7;
+
+ receive_crc = (ubcsp_receive_header[0] & 0x40) >> 6;
+ receive_ack = (ubcsp_receive_header[0] & 0x38) >> 3;
+ receive_seq = (ubcsp_receive_header[0] & 0x07);
+
+ ubcsp_config.receive_packet->channel = (ubcsp_receive_header[1] & 0x0f);
+
+ length =
+ ((ubcsp_receive_header[1] & 0xf0) >> 4) |
+ (ubcsp_receive_header[2] << 4);
+
+#if SHOW_PACKET_ERRORS
+ if (ubcsp_config.receive_packet->reliable)
+ {
+ printf (" : %10d Recv SEQ: %d ACK %d\n",
+ GetTickCount () % 100000,
+ receive_seq,
+ receive_ack);
+ }
+ else if (ubcsp_config.receive_packet->channel != 1)
+ {
+ printf (" : %10d Recv ACK %d\n",
+ GetTickCount () % 100000,
+ receive_ack);
+ }
+#endif
+
+ /* Check for length errors */
+
+#if UBCSP_CRC
+ if (receive_crc)
+ {
+ /* If this packet had a CRC, then the length of the payload
+ should be 2 less than the received size of the payload */
+
+ if (length + 2 != ubcsp_config.receive_index)
+ {
+ /* Slip Length Error */
+
+#if SHOW_PACKET_ERRORS
+ printf ("\n######################## Slip Length Error (With CRC) %d,%d\n", length, ubcsp_config.receive_index - 2);
+#endif
+
+ /* If we have a payload length error, send an ack in return
+ this gets a packet to be resent as quickly as possible */
+
+ ubcsp_config.send_ack = 1;
+ return activity;
+ }
+
+ /* We have a CRC at the end of this packet */
+
+ ubcsp_config.receive_index -= 2;
+
+ /* Calculate the packet CRC */
+
+ crc = 0xffff;
+
+ /* CRC the packet header */
+
+ for (loop = 0; loop < 4; loop ++)
+ {
+ crc = ubcsp_calc_crc (ubcsp_receive_header[loop], crc);
+ }
+
+ /* CRC the packet payload - without the CRC bytes */
+
+ for (loop = 0; loop < ubcsp_config.receive_index; loop ++)
+ {
+ crc = ubcsp_calc_crc (ubcsp_config.receive_packet->payload[loop], crc);
+ }
+
+ /* Reverse the CRC */
+
+ crc = ubcsp_crc_reverse (crc);
+
+ /* Check the CRC is correct */
+
+ if
+ (
+ (((crc & 0xff00) >> 8) != ubcsp_config.receive_packet->payload[ubcsp_config.receive_index]) ||
+ ((crc & 0xff) != ubcsp_config.receive_packet->payload[ubcsp_config.receive_index + 1])
+ )
+ {
+#if SHOW_PACKET_ERRORS
+ printf ("\n######################## CRC Error\n");
+#endif
+
+ /* If we have a packet crc error, send an ack in return
+ this gets a packet to be resent as quickly as possible */
+
+ ubcsp_config.send_ack = 1;
+ return activity;
+ }
+ }
+ else
+ {
+#endif
+ /* No CRC present, so just check the length of payload with that received */
+
+ if (length != ubcsp_config.receive_index)
+ {
+ /* Slip Length Error */
+
+#if SHOW_PACKET_ERRORS
+ printf ("\n######################## Slip Length Error (No CRC) %d,%d\n", length, ubcsp_config.receive_index);
+#endif
+
+ /* If we have a payload length error, send an ack in return
+ this gets a packet to be resent as quickly as possible */
+
+ ubcsp_config.send_ack = 1;
+ return activity;
+ }
+#if UBCSP_CRC
+ }
+#endif
+
+ /*** We have a fully formed packet having passed all data integrity checks ***/
+
+ /* Check if we have an ACK for the last packet we sent */
+
+ if (receive_ack != ubcsp_config.sequence_number)
+ {
+ /* Since we only have a window size of 1, if the ACK is not equal to SEQ
+ then the packet was sent */
+
+ if
+ (
+ (ubcsp_config.send_packet) &&
+ (ubcsp_config.send_packet->reliable)
+ )
+ {
+ /* We had sent a reliable packet, so clear this packet
+ Then increament the sequence number for the next packet */
+
+ ubcsp_config.send_packet = 0;
+ ubcsp_config.sequence_number ++;
+ ubcsp_config.delay = 0;
+
+ /* Notify the caller that we have SENT a packet */
+
+ activity |= UBCSP_PACKET_SENT;
+ }
+ }
+
+ /*** Now we can concentrate of the packet we have received ***/
+
+ /* Check for Link Establishment packets */
+
+ if (ubcsp_config.receive_packet->channel == 1)
+ {
+ /* Link Establishment */
+
+ ubcsp_config.delay = 0;
+
+ /* Find which link establishment packet this payload means
+ This could return 5, meaning none */
+
+ switch (ubcsp_which_le_payload (ubcsp_config.receive_packet->payload))
+ {
+ case 0:
+ {
+ /* SYNC Recv'd */
+
+#if SHOW_LE_STATES
+ printf ("Recv SYNC\n");
+#endif
+
+ /* If we receive a SYNC, then we respond to it with a SYNC RESP
+ but only if we are not active.
+ If we are active, then we have a PEER RESET */
+
+ if (ubcsp_config.link_establishment_state < ubcsp_le_active)
+ {
+ ubcsp_config.link_establishment_resp = 1;
+ }
+ else
+ {
+ /* Peer reset !!!! */
+
+#if SHOW_LE_STATES
+ printf ("\n\n\n\n\nPEER RESET\n\n");
+#endif
+
+ /* Reinitialize the link */
+
+ ubcsp_initialize ();
+
+ /* Tell the host what has happened */
+
+ return UBCSP_PEER_RESET;
+ }
+ break;
+ }
+
+ case 1:
+ {
+ /* SYNC RESP Recv'd */
+
+#if SHOW_LE_STATES
+ printf ("Recv SYNC RESP\n");
+#endif
+
+ /* If we receive a SYNC RESP, push us into the initialized state */
+
+ if (ubcsp_config.link_establishment_state < ubcsp_le_initialized)
+ {
+#if SHOW_LE_STATES
+ printf ("Link Initialized\n");
+#endif
+ ubcsp_config.link_establishment_state = ubcsp_le_initialized;
+ }
+
+ break;
+ }
+
+ case 2:
+ {
+ /* CONF Recv'd */
+
+#if SHOW_LE_STATES
+ printf ("Recv CONF\n");
+#endif
+
+ /* If we receive a CONF, and we are initialized or active
+ then respond with a CONF RESP */
+
+ if (ubcsp_config.link_establishment_state >= ubcsp_le_initialized)
+ {
+ ubcsp_config.link_establishment_resp = 2;
+ }
+
+ break;
+ }
+
+ case 3:
+ {
+ /* CONF RESP Recv'd */
+
+#if SHOW_LE_STATES
+ printf ("Recv CONF RESP\n");
+#endif
+
+ /* If we received a CONF RESP, then push us into the active state */
+
+ if (ubcsp_config.link_establishment_state < ubcsp_le_active)
+ {
+#if SHOW_LE_STATES
+ printf ("Link Active\n");
+#endif
+
+ ubcsp_config.link_establishment_state = ubcsp_le_active;
+ ubcsp_config.send_size = 0;
+
+ return activity | UBCSP_PACKET_SENT;
+ }
+
+ break;
+ }
+ }
+
+ /* We have finished processing Link Establishment packets */
+ }
+ else if (ubcsp_config.receive_index)
+ {
+ /* We have some payload data we need to process
+ but only if we are active - otherwise, we just ignore it */
+
+ if (ubcsp_config.link_establishment_state == ubcsp_le_active)
+ {
+ if (ubcsp_config.receive_packet->reliable)
+ {
+ /* If the packet we've just received was reliable
+ then send an ACK */
+
+ ubcsp_config.send_ack = 1;
+
+ /* We the sequence number we received is the same as
+ the last ACK we sent, then we have received a packet in sequence */
+
+ if (receive_seq == ubcsp_config.ack_number)
+ {
+ /* Increase the ACK number - which will be sent in the next ACK
+ or normal packet we send */
+
+ ubcsp_config.ack_number ++;
+
+ /* Set the values in the receive_packet structure, so the caller
+ knows how much data we have */
+
+ ubcsp_config.receive_packet->length = length;
+ ubcsp_config.receive_packet = 0;
+
+ /* Tell the caller that we have received a packet, and that it
+ will be ACK'ed */
+
+ activity |= UBCSP_PACKET_RECEIVED | UBCSP_PACKET_ACK;
+ }
+ }
+ else
+ {
+ /* Set the values in the receive_packet structure, so the caller
+ knows how much data we have */
+
+ ubcsp_config.receive_packet->length = length;
+ ubcsp_config.receive_packet = 0;
+
+ /* Tell the caller that we have received a packet */
+
+ activity |= UBCSP_PACKET_RECEIVED;
+ }
+ }
+ }
+
+ /* Just return any activity that occured */
+
+ return activity;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_setup_packet **/
+/** **/
+/** This function is called to setup a packet to be sent **/
+/** This allows just a header, or a header and payload to be sent **/
+/** It also allows the header checksum to be precalcuated **/
+/** or calculated here **/
+/** part1 is always 4 bytes **/
+/** **/
+/*****************************************************************************/
+
+static void ubcsp_setup_packet (uint8 *part1, uint8 calc, uint8 *part2, uint16 len2)
+{
+ /* If we need to calculate the checksum, do that now */
+
+ if (calc)
+ {
+ part1[3] =
+ ~(part1[0] + part1[1] + part1[2]);
+ }
+
+ /* Setup the header send pointer and size so we can clock this out */
+
+ ubcsp_config.send_ptr = part1;
+ ubcsp_config.send_size = 4;
+
+ /* Setup the payload send pointer and size */
+
+ ubcsp_config.next_send_ptr = part2;
+ ubcsp_config.next_send_size = len2;
+
+#if UBCSP_CRC
+ /* Initialize the crc as required */
+
+ ubcsp_config.send_crc = -1;
+
+ ubcsp_config.need_send_crc = 1;
+#endif
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_sent_packet **/
+/** **/
+/** Called when we have finished sending a packet **/
+/** If this packet was unreliable, then notify caller, and clear the data **/
+/** **/
+/*****************************************************************************/
+
+static uint8 ubcsp_sent_packet (void)
+{
+ if (ubcsp_config.send_packet)
+ {
+ if (!ubcsp_config.send_packet->reliable)
+ {
+ /* We had a packet sent that was unreliable */
+
+ /* Forget about this packet */
+
+ ubcsp_config.send_packet = 0;
+
+ /* Notify caller that they can send another one */
+
+ return UBCSP_PACKET_SENT;
+ }
+ }
+
+ /* We didn't have a packet, or it was reliable
+ Must wait for ACK before allowing another packet to be sent */
+
+ return 0;
+}
+
+/*****************************************************************************/
+/** **/
+/** ubcsp_poll **/
+/** **/
+/** This is the main function for ubcsp **/
+/** It performs a number of tasks **/
+/** **/
+/** 1) Send another octet to the UART - escaping as required **/
+/** 2) Setup the payload to be sent after the header has been sent **/
+/** 3) Send the CRC for the packet if required **/
+/** **/
+/** 4) Calculate the next Link Establishment State **/
+/** 5) Send a Link Establishment packet **/
+/** 6) Send a normal packet if available **/
+/** 7) Send an ACK packet if required **/
+/** **/
+/** 8) Receive octets from UART and deslip them as required **/
+/** 9) Place received octets into receive header or receive payload buffer **/
+/** 10) Process received packet when SLIP_END is received **/
+/** **/
+/** 11) Keep track of ability of caller to delay recalling **/
+/** **/
+/*****************************************************************************/
+
+uint8 ubcsp_poll (uint8 *activity)
+{
+ uint8
+ delay = UBCSP_POLL_TIME_IMMEDIATE;
+
+ uint8
+ value;
+
+ /* Assume no activity to start with */
+
+ *activity = 0;
+
+ /* If we don't have to delay, then send something if we can */
+
+ if (!ubcsp_config.delay)
+ {
+ /* Do we have something we are sending to send */
+
+ if (ubcsp_config.send_size)
+ {
+ /* We have something to send so send it */
+
+ if (ubcsp_config.send_slip_escape)
+ {
+ /* Last time we send a SLIP_ESCAPE octet
+ this time send the second escape code */
+
+ put_uart (ubcsp_config.send_slip_escape);
+
+ ubcsp_config.send_slip_escape = 0;
+ }
+ else
+ {
+#if UBCSP_CRC
+ /* get the value to send, and calculate CRC as we go */
+
+ value = *ubcsp_config.send_ptr ++;
+
+ ubcsp_config.send_crc = ubcsp_calc_crc (value, ubcsp_config.send_crc);
+
+ /* Output the octet */
+
+ ubcsp_put_slip_uart (value);
+#else
+ /* Just output the octet*/
+
+ ubcsp_put_slip_uart (*ubcsp_config.send_ptr ++);
+#endif
+ }
+
+ /* If we did output a SLIP_ESCAPE, then don't process the end of a block */
+
+ if ((!ubcsp_config.send_slip_escape) && ((ubcsp_config.send_size = ubcsp_config.send_size - 1) == 0))
+ {
+ /*** We are at the end of a block - either header or payload ***/
+
+ /* setup the next block */
+
+ ubcsp_config.send_ptr = ubcsp_config.next_send_ptr;
+ ubcsp_config.send_size = ubcsp_config.next_send_size;
+ ubcsp_config.next_send_ptr = 0;
+ ubcsp_config.next_send_size = 0;
+
+#if UBCSP_CRC
+ /* If we have no successor block
+ then we might need to send the CRC */
+
+ if (!ubcsp_config.send_ptr)
+ {
+ if (ubcsp_config.need_send_crc)
+ {
+ /* reverse the CRC from what we computed along the way */
+
+ ubcsp_config.need_send_crc = 0;
+
+ ubcsp_config.send_crc = ubcsp_crc_reverse (ubcsp_config.send_crc);
+
+ /* Save in the send_crc buffer */
+
+ ubcsp_send_crc[0] = (uint8) (ubcsp_config.send_crc >> 8);
+ ubcsp_send_crc[1] = (uint8) ubcsp_config.send_crc;
+
+ /* Setup to send this buffer */
+
+ ubcsp_config.send_ptr = ubcsp_send_crc;
+ ubcsp_config.send_size = 2;
+ }
+ else
+ {
+ /* We don't need to send the crc
+ either we just have, or this packet doesn't include it */
+
+ /* Output the end of FRAME marker */
+
+ put_uart (SLIP_FRAME);
+
+ /* Check if this is an unreliable packet */
+
+ *activity |= ubcsp_sent_packet ();
+
+ /* We've sent the packet, so don't need to have be called quickly soon */
+
+ delay = UBCSP_POLL_TIME_DELAY;
+ }
+ }
+#else
+ /* If we have no successor block
+ then we might need to send the CRC */
+
+ if (!ubcsp_config.send_ptr)
+ {
+ /* Output the end of FRAME marker */
+
+ put_uart (SLIP_FRAME);
+
+ /* Check if this is an unreliable packet */
+
+ *activity |= ubcsp_sent_packet ();
+
+ /* We've sent the packet, so don't need to have be called quickly soon */
+
+ delay = UBCSP_POLL_TIME_DELAY;
+ }
+#endif
+ }
+ }
+ else if (ubcsp_config.link_establishment_packet == ubcsp_le_none)
+ {
+ /* We didn't have something to send
+ AND we have no Link Establishment packet to send */
+
+ if (ubcsp_config.link_establishment_resp & 2)
+ {
+ /* Send the start of FRAME packet */
+
+ put_uart (SLIP_FRAME);
+
+ /* We did require a RESP packet - so setup the send */
+
+ ubcsp_setup_packet ((uint8*) ubcsp_send_le_header, 0, (uint8*) ubcsp_le_buffer[ubcsp_le_conf_resp], 4);
+
+ /* We have now "sent" this packet */
+
+ ubcsp_config.link_establishment_resp = 0;
+ }
+ else if (ubcsp_config.send_packet)
+ {
+ /* There is a packet ready to be sent */
+
+ /* Send the start of FRAME packet */
+
+ put_uart (SLIP_FRAME);
+
+ /* Encode up the packet header using ACK and SEQ numbers */
+
+ ubcsp_send_header[0] =
+ (ubcsp_config.send_packet->reliable << 7) |
+#if UBCSP_CRC
+ 0x40 | /* Always use CRC's */
+#endif
+ (ubcsp_config.ack_number << 3) |
+ (ubcsp_config.sequence_number);
+
+ /* Encode up the packet header's channel and length */
+ ubcsp_send_header[1] =
+ (ubcsp_config.send_packet->channel & 0x0f) |
+ ((ubcsp_config.send_packet->length << 4) & 0xf0);
+
+ ubcsp_send_header[2] =
+ (ubcsp_config.send_packet->length >> 4) & 0xff;
+
+ /* Let the ubcsp_setup_packet function calculate the header checksum */
+
+ ubcsp_setup_packet ((uint8*) ubcsp_send_header, 1, ubcsp_config.send_packet->payload, ubcsp_config.send_packet->length);
+
+ /* Don't need to send an ACK - we just place on in this packet */
+
+ ubcsp_config.send_ack = 0;
+
+#if SHOW_PACKET_ERRORS
+ printf (" : %10d Send %d Ack %d\n",
+ GetTickCount () % 100000,
+ ubcsp_config.sequence_number,
+ ubcsp_config.ack_number);
+#endif
+ }
+ else if (ubcsp_config.send_ack)
+ {
+ /* Send the start of FRAME packet */
+
+ put_uart (SLIP_FRAME);
+
+#if SHOW_PACKET_ERRORS
+ printf (" : %10d Send ACK %d\n",
+ GetTickCount () % 100000,
+ ubcsp_config.ack_number);
+#endif
+
+ /* The ack packet is already computed apart from the first octet */
+
+ ubcsp_send_ack_header[0] =
+#if UBCSP_CRC
+ 0x40 |
+#endif
+ (ubcsp_config.ack_number << 3);
+
+ /* Let the ubcsp_setup_packet function calculate the header checksum */
+
+ ubcsp_setup_packet (ubcsp_send_ack_header, 1, 0, 0);
+
+ /* We've now sent the ack */
+
+ ubcsp_config.send_ack = 0;
+ }
+ else
+ {
+ /* We didn't have a Link Establishment response packet,
+ a normal packet or an ACK packet to send */
+
+ delay = UBCSP_POLL_TIME_DELAY;
+ }
+ }
+ else
+ {
+#if SHOW_PACKET_ERRORS
+// printf (" : %10d Send LE %d\n",
+// GetTickCount () % 100000,
+// ubcsp_config.link_establishment_packet);
+#endif
+
+ /* Send A Link Establishment Message */
+
+ put_uart (SLIP_FRAME);
+
+ /* Send the Link Establishment header followed by the
+ Link Establishment packet */
+
+ ubcsp_setup_packet ((uint8*) ubcsp_send_le_header, 0, (uint8*) ubcsp_le_buffer[ubcsp_config.link_establishment_packet], 4);
+
+ /* start sending immediately */
+
+ ubcsp_config.delay = 0;
+
+ /* workout what the next link establishment packet should be */
+
+ ubcsp_config.link_establishment_packet = next_le_packet[ubcsp_config.link_establishment_state + ubcsp_config.link_establishment_resp * 4];
+
+ /* We have now delt with any response packet that we needed */
+
+ ubcsp_config.link_establishment_resp = 0;
+
+ return 0;
+ }
+ }
+
+ /* We now need to receive any octets from the UART */
+
+ while ((ubcsp_config.receive_packet) && (get_uart (&value)))
+ {
+ /* If the last octet was SLIP_ESCAPE, then special processing is required */
+
+ if (ubcsp_config.receive_slip_escape)
+ {
+ /* WARNING - out of range values are not detected !!!
+ This will probably be caught with the checksum or CRC check */
+
+ value = ubcsp_deslip[value - SLIP_ESCAPE_FRAME];
+
+ ubcsp_config.receive_slip_escape = 0;
+ }
+ else
+ {
+ /* Check for the SLIP_FRAME octet - must be start or end of packet */
+ if (value == SLIP_FRAME)
+ {
+ /* If we had a full header then we have a packet */
+
+ if (ubcsp_config.receive_index >= 0)
+ {
+ /* process the received packet */
+
+ *activity |= ubcsp_recevied_packet ();
+
+ if (*activity & UBCSP_PACKET_ACK)
+ {
+ /* We need to ACK this packet, then don't delay its sending */
+ ubcsp_config.delay = 0;
+ }
+ }
+
+ /* Setup to receive the next packet */
+
+ ubcsp_config.receive_index = -4;
+
+ /* Ok, next octet */
+
+ goto finished_receive;
+ }
+ else if (value == SLIP_ESCAPE)
+ {
+ /* If we receive a SLIP_ESCAPE,
+ then remember to process the next special octet */
+
+ ubcsp_config.receive_slip_escape = 1;
+
+ goto finished_receive;
+ }
+ }
+
+ if (ubcsp_config.receive_index < 0)
+ {
+ /* We are still receiving the header */
+
+ ubcsp_receive_header[ubcsp_config.receive_index + 4] = value;
+
+ ubcsp_config.receive_index ++;
+ }
+ else if (ubcsp_config.receive_index < ubcsp_config.receive_packet->length)
+ {
+ /* We are receiving the payload */
+ /* We might stop comming here if we are receiving a
+ packet which is longer than the receive_packet->length
+ given by the host */
+
+ ubcsp_config.receive_packet->payload[ubcsp_config.receive_index] = value;
+
+ ubcsp_config.receive_index ++;
+ }
+
+finished_receive:
+ {
+ }
+ }
+
+ if (ubcsp_config.delay > 0)
+ {
+ /* We were delayed so delay some more
+ this could be cancelled if we received something */
+
+ ubcsp_config.delay --;
+ }
+ else
+ {
+ /* We had no delay, so use the delay we just decided to us */
+
+ ubcsp_config.delay = delay;
+ }
+
+ /* Report the current delay to the user */
+
+ return ubcsp_config.delay;
+}
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