ymodem.rar_Ymodem_linux Ymodem_linux ymodem源码_ymodem linux_ymode

#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;//当前数据包编号 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 全局变量 if((fd=_open(device, _O_RDWR|_O_BINARY|_O_NONBLOCK ))==-1)//打开串口 return(COM_OPEN_ERR); count_read=0;//统计收到的字节数 /*进入死循环，向发送方发送一个C*/ for(;;) { delay(10000000); if(_write(fd, &bt,1)==-1) //request sender to send file with CRC check 写失败返回错误码，关闭串口 { printf("write err!\n"); _close(fd); return(COM_WRITE_ERR); } for(i=0;i<0x1fffff;i++)//如果发送C成功，延时后 delay(0xffffffff); if((len=_read(fd,rxdata+count_read,1))==-1)//准备接受发送方发送的第一个包 { 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;//把收到的字节数加到统计字节数中去 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) //如果正确收到包 { if(PacketStartFlagRecv) { PacketStartFlagRecv=0; /*第一帧的第一个字节*/ 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((unsigned char *)rxdata);//包头检查 switch(head_check) { case HEAD_OK: #ifdef DEBUG printf("head check OK!\n"); #endif file_check=procrecdata((unsigned char *)rxdata);//文件数据区检查 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�