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xprquickb
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protocol.c
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C/C++ Source or Header
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1989-08-05
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/*
* xprQuickB.library
* XPR implementation of Compuserve Quick-B protocol, written by Marc Boucher.
*/
/*
* QUICKB.C - Quick B Protocol Support routines
*
* converted to C by Paul M. Resch
* adapted for XPR implementation by Marc Boucher (boucher@jolnet.ORPK.IL.US)
*/
/*
* This module implements the B-Protocol Functions.
*
* bp_DLE should be invoked whenever a <DLE> is received.
* bp_ENQ should be called whenever an <ENQ> is received.
*
* cgetc is an external procedure which returns a character from the
* communications port or -1 if no character is received within the time
* specified (in tenths of seconds).
* cputc is an external procedure which sends a character to the communication
* port.
* create is an external procedure which creates the named file.
* open is an external procedure which opens the named file for input, and
* returns a handle for the file.
* close is an external procedure which closes the file specified by handle.
* read is an external procedure which reads the specified number of bytes
* from the file specified by handle, and returns the number of bytes
* actually read, or a negative error.
* write is an external procedure which writes the specified number of bytes
* to the file specified by handle.
* user_abort is an external procedure which is TRUE if the user wants to stop.
*
* This source was originally derived from QUICKB.INC, version 121687, written
* by Russ Ranshaw, CompuServe Incorporated.
*
*/
extern long user_abort();
extern short cgetc();
extern void cputc();
extern long calla(), callaa(), callad(), calladd(), calladda(), calld();
extern long (*xupdate)(), (*xswrite)(), (*xfopen)(), (*xfclose)(), \
(*xfread)(), (*xsread)(), (*xchkabort)(), (*xfwrite)(), \
(*xchkmisc)(), (*xsetserial)(),(*xsflush)();
#define TRUE 1
#define FALSE 0
#define DLE 16
#define ETX 03
#define NAK 0x15
#define ENQ 05
#define CR 0x0D
#define LF 0x0A
#define MAX_BUF_SIZE 1032 /* Largest data block we can handle */
#define MAX_SA 2 /* Maximum number of waiting packets */
#define DEF_BUF_SIZE 511 /* Default data block */
#define DEF_WS 1 /* I can send 2 packets ahead */
#define DEF_WR 1 /* I can receive single send-ahead */
#define DEF_BS 8 /* I can handle 1024 bytes */
#define DEF_CM 1 /* I can handle CRC */
#define DEF_DQ 1 /* I can handle non-quoted NUL */
#define MAX_ERRORS 10
/* Receive States */
#define R_GET_DLE 0
#define R_GET_B 1
#define R_GET_SEQ 2
#define R_GET_DATA 3
#define R_GET_CHECKSUM 4
#define R_SEND_ACK 5
#define R_TIMED_OUT 6
#define R_SUCCESS 7
/* Send States */
#define S_GET_DLE 1
#define S_GET_NUM 2
#define S_HAVE_ACK 3
#define S_GET_PACKET 4
#define S_TIMED_OUT 5
#define S_SEND_NAK 6
#define S_SEND_ENQ 7
#define S_SEND_DATA 8
typedef struct PACKETB {
int seq; /* Packet's sequence number */
int num; /* Number of bytes in packet */
unsigned char buf[MAX_BUF_SIZE]; /* Actual packet data */
} PACKET;
static PACKET SA_Buf[MAX_SA+1]; /* Send-ahead buffers */
/* Table of control characters that need to be masked */
static char mask_table[] = {
0, 0, 0, 1, 0, 1, 0, 0, /* NUL SOH SOB ETX EOT ENQ SYN BEL */
0, 0, 0, 0, 0, 0, 0, 0, /* BS HT LF VT FF CR SO SI */
1, 1, 0, 1, 0, 1, 0, 0, /* DLE DC1 DC2 DC3 DC4 NAK ^V ^W */
0, 0, 0, 0, 0, 0, 0, 0}; /* CAN ^Y ^Z ESC ? ? ? ? */
static char hex_digit[] = "0123456789ABCDEF";
extern long ctimeouts , cbytes, cnaks, cblocks, gbufsize; /* counts for status */
static int seq_num; /* Current Sequence Number - init by Term_ENQ */
static int checksum; /* May hold CRC */
static int r_size; /* size of receiver buffer */
static unsigned int s_counter, r_counter;
static int timed_out; /* we timed out before receiving character */
static int cchar; /* current character */
static int masked; /* TRUE if ctrl character was 'masked' */
static int packet_received; /* True if a packet was received */
static unsigned char r_buffer[MAX_BUF_SIZE];
/* Other End's Parameters */
static char His_WS; /* Sender's Window Send */
static char His_WR; /* Sender's Window Receive */
static char His_BS; /* Sender's Block Size */
static char His_CM; /* Sender's Check Method */
/* Negotiated Parameters */
static char Our_WS; /* Negotiated Window Send */
static char Our_WR; /* Negotiated Window Receive */
static char Our_BS; /* Negotiated Block Size */
static char Our_CM; /* Negotiated Check Method */
static int Quick_B; /* True if Quick B in effect */
static int Use_CRC; /* True if CRC in effect */
static int buffer_size; /* Our_BS * 4 */
static int SA_Max; /* 1 if SA not enabled, else MAX_SA */
static int SA_Enabled; /* True if Send-Ahead is permitted */
static int ack_SA; /* Which SA_Buf is waiting for an ACK */
static int fill_SA; /* Which SA_Buf is ready for new data */
static int SA_Waiting; /* Number of SA_Buf's waiting for ACK */
static int Aborting; /* TRUE if aborting transfer */
/*
* crc
*
* Calculates XMODEM-style CRC (uses the CCITT V.41 polynomial but
* completely backwards from the normal bit ordering).
*/
static unsigned crc_table[] = {
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
};
static unsigned int crc_16;
/*
* Init_CRC initializes for XMODEM style CRC calculation by setting
* crc_16 to value. Typically value is 0 for XMODEM and -1 for
* B+ Protocl. It returns the initial value.
*/
static int init_CRC (value)
int value;
{
return( crc_16 = value );
}
/*
Upd_CRC updates crc_16 and returns the updated value. */
static unsigned int upd_CRC (value)
unsigned int value;
{
crc_16 = crc_table [((crc_16 >> 8) ^ (value)) & 0xff] ^ (crc_16 << 8);
return( crc_16 );
}
/* Update the checksum/CRC */
static void do_checksum(c)
int c;
{
if (Quick_B && Use_CRC)
checksum = upd_CRC (c);
else
{
checksum = checksum << 1;
if (checksum > 255)
checksum = (checksum & 0xFF) + 1;
checksum = checksum + c;
if (checksum > 255)
checksum = (checksum & 0xFF) + 1;
}
}
static void send_failure( code )
int code;
{
register PACKET *p;
ack_SA = 0;
fill_SA = 0;
SA_Waiting = 0;
Aborting = TRUE; /* inform get_ACK we're aborting */
p = &SA_Buf [0];
p->buf[0] = 'F';
p->buf[1] = code;
if ( send_packet (1))
SA_Flush(); /* Gotta wait for the host to ACK it */
}
/*
* bp_ENQ is called when the terminal emulator receives the character <ENQ>
* from the host. Its purpose is to initialize for B Protocol and tell the
* host that we support Quick B.
*/
void bp_ENQ()
{
seq_num = 0;
buffer_size = 511; /* Set up defaults */
Quick_B = FALSE; /* Not Quick B Protocol */
Use_CRC = FALSE; /* Not CRC_16 */
SA_Enabled = FALSE; /* No Send-Ahead by us */
SA_Max = 1; /* = single packet sent */
cputc (DLE);
cputc ('+');
cputc (DLE);
cputc ('0');
}
static void send_masked_byte(c)
int c;
{
c = c & 0xFF;
if (c < 32)
{
if (mask_table [c] != 0)
{
cputc (DLE);
cputc (c + '@');
}
else
cputc (c);
}
else
cputc (c);
s_counter = (s_counter + 1) % 512;
}
static void send_ack()
{
cputc(DLE);
cputc(seq_num + '0');
}
static void send_nak()
{
cputc(NAK);
}
static void send_enq()
{
cputc(ENQ);
}
static int read_byte()
{
timed_out = FALSE;
cchar = cgetc(100L);
if (cchar < 0 ) {
ctimeouts++;
return( FALSE );
}
r_counter = (r_counter + 1) % 512;
return( TRUE );
}
static int read_masked_byte()
{
masked = FALSE;
if (read_byte() == FALSE)
return( FALSE );
if (cchar == DLE)
{
if (read_byte() == FALSE)
return( FALSE );
cchar &= 0x1F;
masked = TRUE;
}
return( TRUE );
}
/* Increment Sequence Number */
static int incr_seq (value)
int value;
{
return( value == 9 ? 0 : value + 1 );
}
static int read_packet (lead_in_seen, from_send_packet)
int lead_in_seen, from_send_packet;
/* Lead_in_Seen is TRUE if the <DLE><B> has been seen already. */
/* from_send_packet is TRUE if called from Send_Packet */
/* (causes exit on first error detected) */
/* Returns True if packet is available from host. */
{
int State, next_seq, block_num, errors, new_cks;
int i;
packet_received = FALSE;
for(i=0; i<buffer_size; i++ )
r_buffer[i] = 0;
next_seq = (seq_num + 1) % 10;
errors = 0;
if (lead_in_seen) /* Start off on the correct foot */
State = R_GET_SEQ;
else
State = R_GET_DLE;
while (TRUE)
{
switch (State) {
case R_GET_DLE :
if (user_abort())
{
send_failure ('A');
return( FALSE );
}
if (!read_byte())
State = R_TIMED_OUT;
else if ((cchar & 0x7F) == DLE)
State = R_GET_B;
else if ((cchar & 0x7F) == ENQ)
State = R_SEND_ACK;
break;
case R_GET_B :
if (!read_byte())
State = R_TIMED_OUT;
else if ((cchar & 0x7F) == 'B')
State = R_GET_SEQ;
else if (cchar == ENQ)
State = R_SEND_ACK;
else
State = R_GET_DLE;
break;
case R_GET_SEQ :
if (!read_byte())
State = R_TIMED_OUT;
else if (cchar == ENQ)
State = R_SEND_ACK;
else
{
if (Quick_B && Use_CRC)
checksum = init_CRC (-1);
else checksum = 0;
block_num = cchar - '0';
do_checksum(cchar);
i = 0;
State = R_GET_DATA;
}
break;
case R_GET_DATA :
r_counter = 0;
if (!read_masked_byte())
State = R_TIMED_OUT;
else if ((cchar == ETX) && !masked)
{
do_checksum(ETX);
State = R_GET_CHECKSUM;
}
else
{
r_buffer[i] = cchar;
i = i + 1;
do_checksum(cchar);
}
break;
case R_GET_CHECKSUM :
if (!read_masked_byte())
State = R_TIMED_OUT;
else
{
if (Quick_B && Use_CRC)
{
checksum = upd_CRC (cchar);
if (!read_masked_byte())
new_cks = checksum ^ 0xFF;
else
{
checksum = upd_CRC (cchar);
new_cks = 0;
}
}
else new_cks = cchar;
if (new_cks != checksum)
State = R_TIMED_OUT;
else if (r_buffer[0] == 'F') /* Watch for Failure Packet */
State = R_SUCCESS; /* which is accepted regardless */
else if (block_num == seq_num) /* Watch for duplicate block */
State = R_SEND_ACK;
else if (block_num != next_seq)
State = R_TIMED_OUT; /* Bad sequence number */
else
State = R_SUCCESS;
}
break;
case R_TIMED_OUT :
errors = errors + 1;
LastError("TimeOut..");
if ((errors > MAX_ERRORS) || (from_send_packet))
return( FALSE );
send_nak();
if (from_send_packet)
return( FALSE );
State = R_GET_DLE;
break;
case R_SEND_ACK :
send_ack();
State = R_GET_DLE; /* wait for the next block */
break;
case R_SUCCESS :
seq_num = block_num;
r_size = i;
packet_received = TRUE;
return( TRUE );
break;
}
}
}
static void send_data (Buffer_Number)
int Buffer_Number;
{
int i;
register PACKET *p;
s_counter = 0;
p = &SA_Buf [Buffer_Number];
if (Quick_B && Use_CRC)
checksum = init_CRC (-1);
else
checksum = 0;
cputc(DLE);
cputc('B');
cputc(p->seq + '0');
do_checksum(p->seq + '0');
for (i = 0; i<=p->num; i++ )
{
send_masked_byte(p->buf[i]);
do_checksum(p->buf[i]);
}
cputc(ETX);
do_checksum (ETX);
if (Quick_B && Use_CRC)
send_masked_byte (checksum >> 8);
send_masked_byte(checksum);
}
static int incr_SA (old_value)
int old_value;
{
return( old_value == MAX_SA ? 0 : old_value + 1 );
}
/*
* ReSync is called to restablish syncronism with the remote. This is
* accomplished by sending <ENQ><ENQ> and waiting for the sequence
* <DLE><d><DLE><d> to be received, ignoring everything else.
*
* Return is -1 on time out, else the digit <d>.
*/
#define GET_FIRST_DLE 1
#define GET_FIRST_DIGIT 2
#define GET_SECOND_DLE 3
#define GET_SECOND_DIGIT 4
static int ReSync()
{
int State, Digit_1;
cputc (ENQ); /* Send <ENQ><ENQ> */
cputc (ENQ);
State = GET_FIRST_DLE;
while(1)
{
switch (State) {
case GET_FIRST_DLE :
if( !read_byte() )
return( -1 );
if( cchar == DLE )
State = GET_FIRST_DIGIT;
break;
case GET_FIRST_DIGIT :
if( !read_byte() )
return( -1 );
if( (cchar >= '0') && (cchar <= '9') )
{
Digit_1 = cchar;
State = GET_SECOND_DLE;
}
break;
case GET_SECOND_DLE :
if( !read_byte() )
return( -1 );
if( cchar == DLE )
State = GET_SECOND_DIGIT;
break;
case GET_SECOND_DIGIT :
if( !read_byte() )
return( -1 );
if( (cchar >= '0') && (cchar <= '9') )
{
if( Digit_1 == cchar )
return( cchar );
else
{
Digit_1 = cchar;
State = GET_SECOND_DLE;
}
}
else
State = GET_SECOND_DLE;
break;
}
}
}
/*
* get_ACK is called to wait until the SA_Buf indicated by ack_SA
* has been ACKed by the host.
*/
static int get_ACK()
{
int State, errors, block_num, i;
int Sent_ENQ;
int SA_Index;
packet_received = FALSE;
errors = 0;
Sent_ENQ = FALSE;
State = S_GET_DLE;
while( TRUE )
{
switch (State) {
case S_GET_DLE :
if (user_abort())
{
send_failure ('A');
return( FALSE );
}
if (!read_byte())
State = S_TIMED_OUT;
else if (cchar == DLE)
State = S_GET_NUM;
else if (cchar == NAK)
{
LastError("NAK!");
if (++errors > MAX_ERRORS)
return( FALSE );
State = S_SEND_ENQ;
}
else if (cchar == ETX)
State = S_SEND_NAK;
break;
case S_GET_NUM :
if (!read_byte())
State = S_TIMED_OUT;
else if ((cchar >= '0') && (cchar <= '9'))
State = S_HAVE_ACK; /* Received ACK */
else if (cchar == 'B')
State = S_GET_PACKET; /* Try to get packet */
else if (cchar == NAK)
{
if (++errors > MAX_ERRORS)
return( FALSE );
State = S_SEND_ENQ;
LastError("NAK!");
}
else
State = S_TIMED_OUT;
break;
case S_GET_PACKET :
if (read_packet (TRUE, TRUE))
{
if (r_buffer [0] == 'F')
{
send_ack();
return( FALSE );
}
else
return( TRUE );
}
State = S_TIMED_OUT; /* On a bad receive, try again */
break;
case S_HAVE_ACK:
block_num = cchar - '0';
if (SA_Buf [ack_SA].seq == block_num)
{ /* This is the one we're waiting for */
ack_SA = incr_SA(ack_SA);
SA_Waiting--;
return( TRUE );
}
else if (SA_Buf [incr_SA (ack_SA)].seq == block_num &&
(SA_Waiting == 2) )
{ /* Must have missed an ACK */
ack_SA = incr_SA (ack_SA);
ack_SA = incr_SA (ack_SA);
SA_Waiting -= 2;
return( TRUE );
}
else if (SA_Buf [ack_SA].seq == incr_seq (block_num))
{
if( Sent_ENQ )
State = S_SEND_DATA;
else
State = S_GET_DLE;
}
else
State = Aborting ? S_GET_DLE : S_TIMED_OUT;
Sent_ENQ = FALSE;
break;
case S_TIMED_OUT :
LastError("TimeOut..");
if (++errors > MAX_ERRORS)
return( FALSE );
else
{
if( Aborting && (errors > 3) )
return( FALSE );
}
State = S_SEND_ENQ;
break;
case S_SEND_NAK :
if (++errors > MAX_ERRORS)
return( FALSE );
send_nak();
State = S_GET_DLE;
break;
case S_SEND_ENQ :
if (++errors > MAX_ERRORS)
return( FALSE );
cchar = ReSync();
if( cchar == -1 )
State = S_SEND_ENQ;
else
State = S_HAVE_ACK;
Sent_ENQ = TRUE;
break;
case S_SEND_DATA :
SA_Index = ack_SA;
for (i = 1; i<=SA_Waiting; i++ )
{
send_data (SA_Index);
SA_Index = incr_SA (SA_Index);
}
State = S_GET_DLE;
Sent_ENQ = FALSE;
break;
}
}
} /* get_ACK */
static int send_packet (size)
int size;
{
if (SA_Waiting == SA_Max)
if (!get_ACK())
return( FALSE );
seq_num = incr_seq (seq_num);
SA_Buf [fill_SA].seq = seq_num;
SA_Buf [fill_SA].num = size;
send_data (fill_SA);
fill_SA = incr_SA (fill_SA);
SA_Waiting = SA_Waiting + 1;
return( TRUE );
}
/*
* SA_Flush is called after sending the last packet to get host's
* ACKs on outstanding packets.
*/
static int SA_Flush()
{
while( SA_Waiting > 0 )
if (!get_ACK())
return( FALSE );
return( TRUE );
}
/* Send_File is called to send a file to the host */
static int send_file(name)
char name[];
{
long fd;
int n;
register PACKET *p;
ctimeouts = cblocks = gbufsize = cbytes = cnaks = 0L;
Filename(name);
fd = callaa(xfopen, name, "r");
if (!fd)
{
LastError ("Unable to open file");
send_failure('E');
return( FALSE );
}
do
{
p = &SA_Buf [fill_SA];
p->buf[0] = 'N';
gbufsize=(long)buffer_size;
n =(int) calladda(xfread, &p->buf[1], 1L, (long)buffer_size, fd);
if (n > 0)
{
Status("Sending..");
cblocks++;
Bytes(cbytes+(long)n);
OtherStats();
if (send_packet (n) == FALSE) {
cblocks--;
OtherStats();
return( FALSE );
}
cbytes += (long)n;
}
} while( n == buffer_size );
calla(xfclose, fd);
if (n < 0)
{
send_failure ('E');
LastError ("Read failure. Aborting");
return(FALSE);
}
/* Inform host that the file was sent */
p = &SA_Buf [fill_SA];
p->buf[0] = 'T';
p->buf[1] = 'C';
if (send_packet(2) == FALSE)
return( FALSE );
else
{
Status( "Waiting for host..." );
if (!SA_Flush())
return( FALSE );
return( TRUE );
}
}
/*
* do_transport_parameters is called when a Packet type of + is received.
* It sends a packet of our local Quick B parameters and sets the Our_xx
* parameters to the minimum of the sender's and our own parameters.
*/
static do_transport_parameters()
{
register PACKET *p;
His_WS = r_buffer [1]; /* Pick out Sender's parameters */
His_WR = r_buffer [2];
His_BS = r_buffer [3];
His_CM = r_buffer [4];
p = &SA_Buf [fill_SA];
p->buf [0] = '+'; /* Prepare to return our own parameters */
p->buf [1] = DEF_WS;
p->buf [2] = DEF_WR;
p->buf [3] = DEF_BS;
p->buf [4] = DEF_CM;
p->buf [5] = DEF_DQ;
if (!send_packet (5))
return;
if (SA_Flush()) /* Wait for host's ACK on our packet */
{
/* Take minimal subset of Transport Params. */
/* If he can send ahead, we can receive it. */
Our_WR = (His_WS < DEF_WR) ? His_WS : DEF_WR;
/* If he can receive send ahead, we can send it. */
Our_WS = (His_WR < DEF_WS) ? His_WR : DEF_WS;
Our_BS = His_BS < DEF_BS ? His_BS : DEF_BS;
Our_CM = His_CM < DEF_CM ? His_CM : DEF_CM;
if (Our_BS == 0)
Our_BS = 4; /* Default */
buffer_size = Our_BS * 128;
Quick_B = TRUE;
if (Our_CM == 1)
Use_CRC = TRUE;
if (Our_WS != 0)
{
SA_Enabled = TRUE;
SA_Max = MAX_SA;
}
}
}
/*
do_application_parameters is called when a ? packet is received.
This version ignores the host's packet and returns a ? packet
saying that normal B Protocol File Transfer is supported.
(Well, actually it says that no extended application packets are
supported. The T packet is assumed to be standard.) */
static void do_application_parameters()
{
register PACKET *p;
p = &SA_Buf [fill_SA];
p->buf[0] = '?'; /* Build the ? packet */
p->buf[1] = 1; /* The T packet flag */
if (send_packet (1)) /* Send the packet */
SA_Flush();
}
/* Receive_File is called to receive a file from the host */
static int receive_file (name)
char name[];
{
long fd;
long bytes;
ctimeouts = cblocks = gbufsize = cbytes = cnaks = 0L;
Filename(name);
fd = callaa(xfopen, name, "w");
if(!fd)
{
LastError ("Unable to open file for write");
send_failure('E');
return( FALSE );
}
send_ack();
/* Process each incoming packet until 'TC' packet received or failure */
while( TRUE )
{
if (read_packet (FALSE, FALSE))
{
switch (r_buffer[0]) {
case 'N' :
bytes = r_size - 1;
cbytes+=(long)bytes;
cblocks++;
Status("Receiving..");
gbufsize=(long)bytes;
Bytes(cbytes);
OtherStats();
if (calladda(xfwrite,&r_buffer[1],1L,(long)bytes,fd) != (long)bytes )
{
LastError("Write to file failed, aborting");
calla(xfclose, fd);
send_failure ('E');
return( FALSE );
}
send_ack();
break;
case 'T' :
if (r_buffer[1] == 'C')
{
Status("File being closed..");
calla(xfclose, fd);
send_ack();
return( TRUE );
}
else
{
LastError ("Invalid termination packet. Aborting");
calla(xfclose, fd);
send_failure ('N');
return( FALSE );
}
break;
case 'F' :
send_ack();
LastError ("Failure packet received. Aborting");
calla(xfclose, fd);
return( FALSE );
break;
}
}
else
{
LastError ("Failed to receive packet. Aborting");
calla(xfclose, fd);
return( FALSE );
}
}
}
/*
* bp_DLE is called from the main program when the character <DLE> is
* received from the host.
*
* This routine calls read_packet and dispatches to the appropriate
* handler for the incoming packet.
*/
long bp_DLE()
{
int xoff_flag;
int i;
char filename[255];
char str[2];
strcpy( str, " " );
ack_SA = 0; /* Initialize Send-ahead variables */
fill_SA = 0;
SA_Waiting = 0;
Aborting = FALSE; /* not aborting ... yet */
/* <DLE><B> received; begin B Protocol */
xoff_flag = TRUE;
r_counter = 0;
s_counter = 0;
ctimeouts = cblocks = gbufsize = cbytes = cnaks = 0L;
if (Quick_B)
{
if(Use_CRC) Status ("Quick B is in effect, using CRC");
else Status ("Quick B is in effect without CRC");
if (Our_WS != 0) { /* Allow send-ahead if other end agrees */
Filename("** Send-Ahead enabled");
TimeOut(30L);
}
}
if (read_packet (TRUE, FALSE))
{
/* Dispatch on the type of packet just received */
switch (r_buffer[0]) {
case 'T': /* File Transfer Application */
switch (r_buffer[1]) {
case 'D' : /* downloading */
break;
case 'U' : /* uploading */
break;
default :
send_failure('N');
/* return(TRUE);*/
}
switch (r_buffer[2]) {
case 'A': /* ascii file */
break;
case 'B': /* binary file */
break;
default :
send_failure('N'); /* not implemented */
/* return(TRUE);*/
}
i = 2;
strcpy( filename, "" );
while( (r_buffer[i] != 0) && (i < r_size - 1) )
{
i = i + 1;
str[0] = r_buffer[i];
strcat( filename, str );
}
if (r_buffer[1] == 'U')
{
if( send_file(filename) ) {
TimeOut(25L);
Status( "Transfer completed!" );
}
else {
TimeOut(25L);
Status("Transfer failed!");
}
TimeOut(50L);
return(TRUE);
}
else
{
if( receive_file(filename) ) {
TimeOut(25L);
Status( "Transfer completed!" );
}
else {
TimeOut(25L);
Status("Transfer failed!");
}
TimeOut(50L);
return(TRUE);
}
break;
case '+': /* Received Transport Parameters Packet */
do_transport_parameters();
break;
case '?': /* Received Application Parameters Packet */
do_application_parameters();
break;
default: /* Unknown packet; tell host we don't know */
send_failure ('N');
break;
} /* of case */
} /* of if read_packet the */
return(FALSE);
}