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- /* Copyright (C) 1992,1993 Peter Edward Cann, all rights reserved.
- */
-
- #include<stdio.h>
- #include<bios.h>
- #include<dos.h>
- #include<fcntl.h>
- #include<sys\types.h>
- #include<sys\stat.h>
- #include<signal.h>
- #include"port.h"
-
- #define NAK 21
- #define ACK 6
- #define SOH 1
- #define EOT 4
- #define CAN 24
-
- unsigned long tick;
-
- void (interrupt far *oldtick)();
-
- void interrupt far tickhndl()
- {
- tick++;
- }
-
- sendchar(c)
- unsigned char c;
- {
- while(!((inp(basereg+STATREG)&TXMTMASK)&&(inp(basereg+MSTATREG)&CTSMASK)))
- if(_bios_keybrd(_KEYBRD_READY))
- if((_bios_keybrd(_KEYBRD_READ)&0xff)==0x03)
- quit();
- outp(basereg, c);
- }
-
- int follow;
-
- int rcharto(ticks)
- int ticks;
- {
- int c;
- tick=0L;
- while(1)
- {
- if(_bios_keybrd(_KEYBRD_READY))
- if((_bios_keybrd(_KEYBRD_READ)&0xff)==0x03)
- quit();
- if(tick>ticks)
- return(-1); /* NOTE: This is an INT!!! */
- if(follow!=index)
- {
- c=buf[follow++];
- if(follow>=TBUFSIZ)
- follow=0;
- return(c);
- }
- }
- }
-
-
- unsigned char block[128];
-
- rblock()
- {
- int i, blockn, invblockn, rchecksum, checksum;
- checksum=0;
- if((blockn=rcharto(20))==-1)
- return(-1);
- printf("Block %d: ", blockn);
- if((invblockn=rcharto(20))==-1)
- return(-1);
- for(i=0;i<128;++i)
- {
- if((block[i]=rcharto(20))==-1)
- {
- printf("Timeout in data phase after %d bytes.", i);
- return(-1);
- }
- checksum+=block[i];
- checksum&=0xff;
- }
- if((rchecksum=rcharto(20))==-1)
- {
- printf("Timeout waiting for checksum.\n");
- return(-1);
- }
- if(((invblockn^0xff)&0xff)!=blockn)
- {
- printf("Bad complement block number.\n");
- return(-1);
- }
- if(checksum!=rchecksum)
- {
- printf("Checksum mismatch. Here=%02x There=%02x.\n", checksum, rchecksum);
- return(-1);
- }
- return(blockn);
- }
-
- quit()
- {
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(99);
- }
-
- main(argc, argv)
- int argc;
- char **argv;
- {
- int i, j, outfd, ok, c;
- long nbytes;
- unsigned char blocknum;
- index=follow=0;
- printf("Copyright (C) 1992 Peter Edward Cann, all rights reserved.\n");
- printf("xmodem checksum receive of %s.\n", argv[4]);
- if(argc!=5)
- {
- printf("USAGE: xmodemr <comnum> <bps> <stopbits> <file pathname>\n");
- exit(1);
- }
- if((outfd=open(argv[4], O_WRONLY|O_BINARY|O_CREAT|O_TRUNC, S_IWRITE))==-1)
- {
- printf("Error opening file %s.\n", argv[4]);
- exit(2);
- }
- comnum=atoi(argv[1])-1;
- speed=atoi(argv[2]);
- databits='8';
- parity='n';
- stopbits=argv[3][0];
- setport();
- readset();
- oldtick=_dos_getvect(0x1c);
- signal(SIGINT, quit);
- _dos_setvect(0x1c, tickhndl);
- setup();
- ok=nbytes=0;
- for(i=0;i<10;++i)
- {
- sendchar(NAK);
- c=rcharto(200);
- if(c==SOH)
- {
- ok=1;
- break;
- }
- }
- if(!ok)
- {
- printf("No SOH after 10 10-second-spaced NAKs.\n");
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(10);
- }
- blocknum=1;
- for(i=0;i<10;++i)
- {
- printf("\nSeeking block %d: ", blocknum);
- if((c=rblock())==blocknum)
- {
- i=0;
- if(write(outfd, block, 128)!=128)
- {
- printf("Write error.\n");
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(13);
- }
- nbytes+=128;
- printf("Successful. Bytes so far: %ld", nbytes);
- blocknum=(blocknum+1)&0xff;
- sendchar(ACK);
- }
- else
- if(c==-1)
- {
- while(rcharto(20)!=-1);
- sendchar(NAK);
- }
- else if(c<blocknum)
- sendchar(ACK);
- else
- {
- printf("\nSender skipped a block; cancelling transfer.\n");
- for(j=0;j<10;++j)
- sendchar(CAN);
- while(!(inp(basereg+STATREG)&TXSHMTMASK));
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(14);
- }
- do
- {
- c=rcharto(200);
- if(c==CAN)
- c=rcharto(200);
- }
- while((c!=EOT)&&(c!=SOH)&&(c!=CAN)&&(c!=-1));
- if(c==EOT)
- {
- sendchar(ACK);
- printf("\nTransfer successful.\n");
- close(outfd);
- while(!(inp(basereg+STATREG)&TXSHMTMASK));
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(0);
- }
- if(c!=SOH)
- {
- if(c==-1)
- printf("Timeout waiting for SOH or EOT.\n");
- else
- printf("\nReceived two consecutive CANcel codes (^X).\n");
- cleanup(0);
- _dos_setvect(0x1c, oldtick);
- exit(11);
- }
- }
- printf("Retry limit exceeded.\n");
- cleanup(0);
- _dos_setvect(0x1c, oldvect);
- exit(12);
- }
-