📄 receive.c
字号:
#include "ymodem.h"
/***************************************************************************/
unsigned int count_read=0; /*the bytes of datas received from buffer. count from every packet begin*/
unsigned char PacketStartFlagRecv=1;/*indicate one packet begin*/
unsigned int PacketLen=0;
unsigned char blknum_cur=0;
char rxdata[1029]; /* An 8-bit integerthat is not signed.*/
char first_flag=1; /*it should be set to 1 every time when a file ready to transfer*/
FILE* fp_recv=NULL;
char* filename;
char filename_change=0;
unsigned int BlockLength;
unsigned int RealLen=0; /*FileLen:record the file length left if this field in the first block*/
/*ReaLen: the real block length barring pads in the last block*/
char* get_name(unsigned char* rec_buf);
void get_length(unsigned int name_len,unsigned char* rec_buf);
int procheader(unsigned char* rec_buf);
int procrecdata(unsigned char* rec_buf);
int control_recv(char* device)
{
int head_check;
int file_check;
int i;
int len;
int CAN_CNT=0;
char bt;
char test=1;
bt='C';
CrcFlag=1; //bt="C":meant CRC check
if((fd=_open(device, _O_RDWR|_O_BINARY|_O_NONBLOCK ))==-1)
return(COM_OPEN_ERR);
count_read=0;
for(;;)
{
delay(10000000);
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
printf("write err!\n");
_close(fd);
return(COM_WRITE_ERR);
}
for(i=0;i<0x1fffff;i++)
delay(0xffffffff);
if((len=_read(fd,rxdata+count_read,1))==-1)
{
if(errno==EAGAIN)
{
if(test)
{
test=0;
printf("waiting...............\n");
}
continue;
}
_close(fd);
return(COM_READ_ERR);
}
if(len)
{
#ifdef DEBUG
printf("%x\n",rxdata[0]);
#endif
count_read+=len;
break;
}
}
while(1)
{
if((len=_read(fd,rxdata+count_read,1))==-1)
{
if(errno==EAGAIN)
{
continue;
}
printf("read fail!we have read %d bytes\n",count_read);
return(COM_READ_ERR);
}
else
{
count_read+=len;
}
if(count_read)
{
if(PacketStartFlagRecv)
{
PacketStartFlagRecv=0;
switch(rxdata[0])
{
case SOH:
if(CAN_CNT)
CAN_CNT=0;
#ifdef DEBUG
printf("SOH!128 bytes per packet!\n");
#endif
PacketLen=133; //CRC check :128+5
BlockLength=128;
break;
case STX:
if(CAN_CNT)
CAN_CNT=0;
#ifdef DEBUG
printf("STX!1024 bytes per packet!\n");
#endif
PacketLen=1029; //case CRC check
BlockLength=1024;
break;
case EOT:
{
if(CAN_CNT)
CAN_CNT=0;
#ifdef DEBUG
printf("get EOT!\n");
#endif
printf("file has been completly transfered!\n");
if(filename_change)
{
filename_change=0;
printf("File existed! Save it as %s \n",filename);
}
printf("File length: %dbytes\n",FileLenBkup);
if(*filename!=(char)NULL)
{
free(filename);
*filename=(char)NULL;
}
RealLen=0;
FileLen=0;
PacketLen=0;
count_read=0;
blknum_cur=0;
PacketStartFlagRecv=1;
first_flag=1; //wait for next file
bt=(char)ACK; // "ACK":config the file end
if(_write(fd,&bt,1)==-1)
{
_close(fd);
return(COM_WRITE_ERR);
}
bt='C'; //request continue transmission with CRC check
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
break;
}
case CAN:
CAN_CNT++;
count_read=0;
PacketStartFlagRecv=1;
break;
default:
{
if(CAN_CNT)
CAN_CNT=0;
printf("unvalid packet head,retry!the first data is:0x%x\n",rxdata[0]);
PacketStartFlagRecv=1;
count_read=0;
bt=(char)NAK; // "NAK":indicate retransmission
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
printf("write fail!\n");
_close(fd);
return(COM_WRITE_ERR);
}
}
}
}
}
if(CAN_CNT==2)
{
printf("transmittion is canceled by user!\n");
if(*filename!=(char)NULL)
remove(filename);
_close(fd);
exit(0);
}
if(!count_read) //get EOT or unvilid packet head or CAN
continue;
if(count_read==PacketLen)
{
#ifdef DEBUG
printf("get a packet completly!count_read:%d\n",count_read);
#endif
PacketStartFlagRecv=1;
count_read=0;
head_check=procheader(rxdata);
switch(head_check)
{
case HEAD_OK:
#ifdef DEBUG
printf("head check OK!\n");
#endif
file_check=procrecdata(rxdata);
switch(file_check)
{
case FILE_OPEN_ERR:
#ifdef DEBUG
printf("ERROR occured when open the file!\n");
#endif
if(first_flag)
{
bt=(char)NAK; //filename packet .retrans if error occured
if(_write(fd, &bt,1)==-1) //request the sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
}
else
{
bt=(char)CAN;
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
delay(10000000);
_close(fd);
exit(0);
}
case NO_MORE_FILE:
#ifdef DEBUG
printf("Files have been transfered completly\n");
#endif
bt=(char)ACK; //加入发送编辑框对应字符串 "ACK";确认结束
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
delay(10000000);
_close(fd);
exit(0);
default:
#ifdef DEBUG
printf("continue next packet.....\n");
#endif
bt=(char)ACK; //加入发送编辑框对应字符串 "ACK",指示继续
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
if(first_flag)
{
bt='C'; //加入发送编辑框对应字符串 "C";指示以CRC检测的方式发送文件内容
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
}
}
break;
case FORMAT_UNSUPPORT:
#ifdef DEBUG
printf("ERROR! Unsupported Format!\n");
#endif
if(first_flag)
{
bt=(char)NAK; //文件名数据包，出错指示重发
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
}
else
{
bt=(char)CAN; //加入发送编辑框对应字符串 "CAN";指示结束
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
_close(fd);
exit(FORMAT_UNSUPPORT);
}
break;
case CRC_ERR:
#ifdef DEBUG
printf("CRC ERROR!\n");
#endif
case BLK_REPEAT:
#ifdef DEBUG
printf("ERROR! Blocks repeat!\n");
#endif
bt=(char)NAK; //加入发送编辑框对应字符串 "NAK";指示重发
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
break;
case BLK_LOSS:
#ifdef DEBUG
printf("ERROR! Blocks lost!\n");
#endif
if(first_flag)
{
bt=(char)NAK; //文件名数据包，出错指示重发
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
// delay(10000000);
}
else
{
bt=(char)CAN; //加入发送编辑框对应字符串 "CAN";指示结束
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check
{
_close(fd);
return(COM_WRITE_ERR);
}
_close(fd);
exit(-1);
}
}
}
}
}
/*************************************************************************/
/*************************************************************************/
int procheader(unsigned char* rec_buf)
{
unsigned int i;
unsigned short oldcrc=0,checksum=0;
unsigned char blknum;
/*check blocknum*/
blknum=rec_buf[1];
if(blknum!=blknum_cur)
{
if(blknum==blknum_cur-1)
{
blknum_cur-=1;
return(BLK_REPEAT);
}
else
{
return(BLK_LOSS);
}
}
blknum_cur=blknum+1;
/*check crc*/
if(CrcFlag)
{
for(i=3;i<BlockLength+5;i++)
{
oldcrc=updcrc(rec_buf[i], oldcrc);
}
if (oldcrc & 0xFFFF)
{
blknum_cur-=1;
return(CRC_ERR);
}
}
else
{
/**********************reserved for checksum Pro******************************/
for(i=3;i<BlockLength+3;i++)
{
checksum+=rec_buf[i];
}
if((checksum-rec_buf[i])&0377)
{
return(CHECKSUM_ERR);
}
}
return(HEAD_OK);
}
/***************************************************************/
/***************get block;the first block has filename**********/
/***************************************************************/
int procrecdata(unsigned char* rec_buf)
{
// int percent_new;
if(first_flag&&(rec_buf[1]==0)) /*the first block (if num_blocks>256,needed first_flag)*/
{
filename=get_name(rec_buf);
if(strlen(filename))
{
get_length(strlen(filename),rec_buf); /*get FielLen*/
#ifndef WINYWY
while(access(filename,F_OK)==0)
{
strcat(filename,"~");
if(!filename_change)
filename_change=1;
}
#endif
}
else
{
if(*filename!=(char)NULL)
{
free(filename);
*filename=(char)NULL;
}
return(NO_MORE_FILE);/*empty file name:sender indicate no more files*/
}
}
else
{
#ifdef DEBUG
printf("blknum:%d\n",rec_buf[1]);
#endif
if(first_flag)
{
first_flag=0;
}
if((fp_recv=fopen(filename,"ab"))==NULL)
{
return(FILE_OPEN_ERR);
}
if(FileLen&&(FileLen<BlockLength))
{
RealLen=FileLen;
FileLen=0;
}
else
{
RealLen=BlockLength;
FileLen-=BlockLength;
}
fwrite(rec_buf+3,RealLen,1,fp_recv);/*put the datas in file*/
fclose(fp_recv);
}
return 0;
}
char* get_name(unsigned char* rec_buf)
{
unsigned int i;
char* file_name=(char*)malloc(BlockLength);
memset(file_name,'\0',BlockLength);
for(i=3;i<BlockLength+3;i++)
{
if(rec_buf[i]=='\0')
break;
else
file_name[i-3]=rec_buf[i];
}
return file_name;
}
void get_length(unsigned int name_len,unsigned char* rec_buf)
{
unsigned short i;
unsigned char count_len=0;
unsigned int pos_len;
pos_len=name_len+4;
for(i=pos_len;;i++)
{
if((rec_buf[i]!=0x20)&(rec_buf[i]!='\0'))/*space and null*/
count_len++;
else
break;
}
for(i=pos_len;count_len>0;i++)
{
FileLen+=(unsigned int)((rec_buf[i]&0x0f)*pow(10,--count_len));
}
FileLenBkup=FileLen;
return;
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -