The TFTP client is fully compliant with RFC-1350, source code.

/ ************************************************** ** TFTP Client Compatible with RFC-1350 * Compile Under Visiual C or Borland C * Author Email: HelloWorld1@163.com ********************************* *********************************** /

#define _vc / * if Compile Under Visiual C Else undefine this * / # include #include #include

#ifndef MakeWord # Define MakeWord (L, H) ((Word)) | ((Word)) | ((Word)) << 8))) # Endif # define WSA_MAJOR_VERSION 1 # Define WSA_MINOR_VERSION 1 # define WSA_VERSION MAKEWORD (WSA_MAJOR_VERSION, WSA_MINOR_VERSION)

/ * Read / Write Request Packet Format 2 Bytes String 1 Byte String 1 Byte ------------------------------------------------------------------------------------------------------------------------------------------------ -------------- | Opcode | FileName | 0 | MODE | 0 | ------------------------- -----------------------

* / # define tftp_rrq 1 / * read request (rrq) * / # define tftp_wrq 2 / * Write Request (WRQ) * /

/ * Data packet format 2 bytes 2 bytes n bytes ---------------------------------- | Opcode | Block # | DATA | --------------------------------- * / # define tftp_data 3 / * data (data) * /

/ * ACK PACKET FORMAT 2 BYtes 2 Bytes --------------------- | Opcode | BLOCK # | -------------- ------- * / # Define TFTP_ACK 4 / * ACKNOWLEDGMENT (ACK) * /

/ * Error packet format 2 bytes 2 bytes string 1 Byte -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --- | opcode | Errorcode | Errmsg | 0 | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --- * / # Define TFTP_ERROR 5 / * Error (Error) * /

#define TFTP_NETASCII 0 # define TFTP_OCTET 1 # define TFTP_WSTAT_FIRSTACK 0 # define TFTP_WSTAT_NEXTACK 1 # define TFTP_WSTAT_LASTACK 2 # define MAX_RETRY 3 # define TFTP_NOTEND_DATALEN 512 2 2 # ifdef _VC # pragma comment (lib, "Wsock32.lib") #endif

TypedEf void (* cmdfunc) (CHAR [] [256], int pcount); typedef struct _cmdnum {char * cmd; int num; int paramcount; cmdfunc callback;} cmdnum, * pcmdnum;

Void ConnectTo (Char CMD []; Void SetOCTET (CHAR CMD [] [256], INT PCOUNT); Void SetASCII (Char CMD [] [256], INT PCOUNT); Void Quit (Char CMD [】 [256], int pcount; void showhelp (char cmd [] [); void test (char cmd [] [256], int pcount); void getfile (Char cmd [] [256] , int pcount; void putfile (CHAR CMD [] [256], int Pcount); int stripcmd (char * s, char cmd [] [[256]); void parsecmd (char * s); int getcmdnum (char * s Int Makereq (Char Type, CHAR * Buffer, Int size); int makeck (unsigned short num, char * buffer, int size); void showsiSInfo ();

Cmdnum cmdlist [] = {{"Help", 1, 0, showhelp}, {"exit", 2, 0, quit}, {"TEST", 3, 0, test}, {"get", 4, 1 Getfile}, {"put", 5, 2, putfile}, {"octet", 6, 0, setock}, {"ASCII", 7, 0, setascii}, {"connect", 8, 1, connection }};

Char * helptext = "Help: show this text / n / EXIT: EXIT PRAGRAM / N / CTET: SET FILE MODE TO OCTET / N / ASCII: SET File Mode to Netascii / N / Connect Remoteip: Connect To Server / N / Get FileName: GET File from Server / N / Put LocalName RemoteFileName: Upload File to Server / N ";

Socket Sock = INVALID_SOCKET; Char Deshost [256] = "127.0.0.1"; int filemode = tftp_netascii; int main (int Argc, char * argv []) {

CHAR CMD [256]; INT RET = 0; SockAddr_in Addr; ShowsysInfo (); IF (WsaStartup (WSA_Version, & Stwsadata! = 0) {Printf ("can't start socket / n"); exit (0 } SOCK = Socket (PF_INET, SOCK_DGRAM, 0); if (SOCK == Invalid_socket) {Printf ("can't create socket / n"); exit (0);} addr.sin_family = pf_inet; addr.sin_port = INADDR_ADR.S_ADDR = INADDR_ADDR = INADDR_ADDR = INADDR_Addr = INADDR_Addr = INADDR_Addr = INADDR_Addr (Bind (Struct SockAddr *) & addr, sizeof (addr))! = 0) {Printf ("can't bind socket / n"); exit (0 );} While {fflush (stdin); Printf ("#"); gets (cmd); Parsecmd (cmd);} return 0;}

Void showsysInfo () {Printf ("TFTP Client Version 1.0 / N");

} int stripcmd (char * s) {INT i = 0; char * token = null; char seps [] = ", / t / n"; token = STRTOK (S, SEPS); While (token! = null) {IF (i> 2) Break; strcpy (cmd [i], token); token = strtok (null, seps); i ;} return i;} int getcmdnum (char * s) { INT i = 0; for (i = 0; i

Void Parsecmd (Char * S) {Char CMD [3] [256]; int pcount = 0; int Num = -1; pcount = stripcmd (s, cmd); Num = getCmdnum (cmd [0]); if (NUM == - 1) {Printf ("No Such Commond / N"); return;} else {cmdlist [Num] .callback (cmd, pcount-1);}}

Void Quit (CHAR CMD [】 [256], int pcount) {Printf ("exit to system / n"); ClosSocket (SOCK); exit (0);}

Void Showhelp (Char cmd [] ["{printf (helptext);

Void test (char cmd [] ["[256], int pcount) {}

Void setOCTet (CHAR CMD [] [256], INT PCOUNT) {filemode = tftp_ocTet; Printf ("set file mode to octet / n");} void setascii (char cmd [] [256], int pcount) {fileMode = TFTP_Netascii; Printf ("Set File Mode To Netasci / N);

Void ConnectTo (Char CMD [] [("USAGE: Connect Remoteip / N"); Return;} STRCPY (DESTHOST, CMD [1]);}

INT Makeck (unsigned short num, char * buffer, int size) {int pos = 0; buffer [pOS] = 0; POS ; buffer [POS] = TFTP_ACK; POS ; buffer [POS] = (NUM >> 8); POS ; buffer [POS] = (char) NUM; POS ; Return Pos;

INT Makereq (Char Type, CHAR * Buffer, INT Size {INT POS = 0; Unsigned INT i = 0; CHAR S [32] = ""; if (Mode == TFTP_Netascii) STRCPY s, "Netascii"); Else Strcpy (S, "OCTET"); Buffer [POS] = 0; POS ; Buffer [POS] = Type; POS ; for (i = 0; i

INT Makedata (int Num, Char * Data, int buffs) {int pos = 0; buffer [pOS] = 0; POS ; buffer [POS] = TFTP_DATA; POS ; Buffer [POS] = CHAR) (NUM >> 8); POS ; buffer [POS] = (char) NUM; POS ; Memcpy (& Buffer [POS], DATA, DATASIZE); POS = POS DATASIZE; RETURN POS

}

Void getFile (Char cmd [] () {char sendbuf [1024] = {0}; char recvbuf [1024] = {0}; SockAddr_in addr; intenddr_in from; int.comlen = 0; int RET = 0 ; Int LEN = 0; fd_set fdr; int RETRY = 0; struct timeval timeout = {5, 0}; int stat = 0; int lastdata = 0; file * file; int flen = 0; INT C; if = 1) {Printf ("usage: get filename / n"); return;} if ((file = fopen (cmd [1], "r"))))! = Null) {printf ("File% s already EXITS, OVERWRITE? Y / N ", CMD [1]); While (TRUE) {c = getCH (); if ('y' == TouPper (c)) {printf (" / n "); fclose (file); Break;} else if ('n' == Toupper (c)) {printf ("/ n"); fclose (file); return;}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}} b ")) == null) {Printf (" can't create file / n "); return;} len = Makereq (TFTP_RRQ, FileMode, CMD [1], SendBuf, Sizeof (Sendbuf)); addr.sin_family = Pf_inet; from.sin_family = pf_inet; addr.sin_port = htons (69); addr.sin_addr.s_addr = inet_addr (desthost); Ret = Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, s Izeof (addr); while {fd_zero (& fdr); fd_set (sock, & fdr); RET = SELECT (SOCK, & FDR, NULL, NULL, & TIMEOUT); if (Socket_ERROR == RET) {Printf ("Socket Error / N "); fclose (file);} else if (0 == RET) {f (max_retry == Retry) {printf (" time out / n "); fclose (file); return;} sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr)); Retry ;} else {if (fd_isset (sock, & fdr)) {Retry = 0; fromlen = sizeof (SockAddr);

RET = Recvfrom (Sock, Recvbuf, SizeOf (Recvbuf), 0, (SockAddr *) & from, & fromLomlen; IF (TFTP_ERROR == Recvbuf [1]) {fclose (file); Printf ("Error% D:% S / N ", Recvbuf [3], & Recvbuf [4]); RETURN;} if (0 == STAT) {addr.sin_port = from.sin_port; stat = 1;} if (tftp_data == recvbuf [1]) {LastData = Recvbuf [2] * 256 recvbuf [3]; len = makeck (Lastdata, Sendbuf, Sizeof (SENDBUF)); Sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr); if (RET

Void Putfile (CHAR CMD []) {25}; char recvbuf [1024] = {0}; char DATABUF [1024] = {0}; sockaddr_in addr; SockAddr_in from ; Int = 0; int LEN = 0; fd_set fdr; int RETRY = 0; struct timeVal timeout = {5, 0}; int stat = tftp_wstat_firstack; int laastack = 0; file * file; int Flen = 0; int blocknum = 0; size_t rlen = 0; if (pcount! = 2) {Printf ("USAGE: PUT LOCALFILENAME RemoteFileName / N"); Return;} IF ((file = fopen (cmd [1], " R ")) == NULL) {Printf (" File% s Not Found / N ", CMD [1]); Return;} len = Makereq (TFTP_WRQ, FileMode, CMD [2], Sendbuf, Sizeof (Sendbuf)) Addr.sin_family = pf_inet; addr.sin_port = htons (69); addr.sin_addr.s_addr = inet_addr (desthost); Ret = Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr)) ; If (File = FOPEN (CMD [1], "R")) == NULL) {Printf ("can't open file% s / n", cmd [1]); return;} while (TRUE) {FD_ZERO (& FDR); FD_SET (SOCK, & FDR); RET = SELECT (Sock, & FDR, NULL, NULL, & TIMEOUT); if (S Ocket_ERROR == RET) {Printf ("socket error / n"); fclose (file); return;} else if (0 == RET) {if (max_retry == retry) {Printf ("time out / n") Fclose (file);} Sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr)); Retry ;} else {RETRY = 0; fromlen = sizeof (sockaddr); return = recvfrom (SOCK, RECVBUF, 0, (SOCKADDR *) & from, & fromLen; if (tftp_error == recvbuf [1]) {fclose (file); Printf ("Error% D:% S / N"

, RECVBUF [3], & Recvbuf [4]); RETURN;} if (tftp_ack == recvbuf [1]) {Lastack = Recvbuf [2] * 256 recvbuf [3]; switch (stat) {copy tftp_wstat_firstack: IF ( 0 == lastack) {stat = tftp_wstat_nextack; addr.sin_port = from.sin_port; rlen = fread (DatabaseF, 1,512, file); flen = flen rlen; if (rlen <512 && feof (file) {stat = tftp_wstat_lastack } Else if (File) {Printf ("Error: Read file / N"); fclose (file); Return;} block ; len = makedata (blockdata (blockdata (blockdata (block, sizeof (sendbuf)) Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr)); Printf ("% D Byte Send / R", Flen);} else {fclose (file); Printf ("Error Ack Number "); return;} Break; case tftp_wstat_nextack: IF (Lastack == Blocknum) {rlen = fread (DataBuf, 1,512, file); flen = flen rlen; IF (RLLEN <512 && Feof (file) {stat = tftp_wstat_lastack;} else if (File) {Printf ("Error: Read file / n"); fclose (file); return;} boxNum ; len = Makedata (Blocknum, DataBuf, Rlen, Sendbuf, Sizeof (Sendbuf); Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr); Printf ("% D Byte Send / R", Flen } Else {fclose (file); Printf ("Error Ack Number"); Return;} Break; Case TFTP_WSTAT_LASTACK: IF (Lastack ==

Blocknum) {Printf ("% D Byte Send / N", Flen); Return;} else {fclose (file); Printf ("Error Ack Number"); return;}}} / *** ********************************************** TFTP Client Compatible with RFC-1350 * Compile Under Visiual C or Borland C * Author Email: HelloWorld1@163.com ****************************************** ********************** /

#define _vc / * if Compile Under Visiual C Else undefine this * / # include #include #include

#ifndef MakeWord # Define MakeWord (L, H) ((Word)) | ((Word)) | ((Word)) << 8))) # Endif # define WSA_MAJOR_VERSION 1 # Define WSA_MINOR_VERSION 1 # define WSA_VERSION MAKEWORD (WSA_MAJOR_VERSION, WSA_MINOR_VERSION)

/ * Read / Write Request Packet Format 2 Bytes String 1 Byte String 1 Byte ------------------------------------------------------------------------------------------------------------------------------------------------ -------------- | Opcode | FileName | 0 | MODE | 0 | ------------------------- -----------------------

* / # define tftp_rrq 1 / * read request (rrq) * / # define tftp_wrq 2 / * Write Request (WRQ) * /

/ * Data packet format 2 bytes 2 bytes n bytes ---------------------------------- | Opcode | Block # | DATA | --------------------------------- * / # define tftp_data 3 / * data (data) * /

/ * ACK PACKET FORMAT 2 BYtes 2 Bytes --------------------- | Opcode | BLOCK # | -------------- ------- * / # Define TFTP_ACK 4 / * ACKNOWLEDGMENT (ACK) * /

/ * Error packet format 2 bytes 2 bytes string 1 Byte -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --- | opcode | Errorcode | Errmsg | 0 | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --- * / # define TFTP_ERROR 5 / * Error (ERROR) * / # define TFTP_NETASCII 0 # define TFTP_OCTET 1 # define TFTP_WSTAT_FIRSTACK 0 # define TFTP_WSTAT_NEXTACK 1 # define TFTP_WSTAT_LASTACK 2 # define MAX_RETRY 3 # define TFTP_NOTEND_DATALEN 512 2 2

#ifdef _vc # Pragma Comment (Lib, "Wsock32.lib" #ENDIF

TypedEf void (* cmdfunc) (CHAR [] [256], int pcount); typedef struct _cmdnum {char * cmd; int num; int paramcount; cmdfunc callback;} cmdnum, * pcmdnum;

Void ConnectTo (Char CMD []; Void SetOCTET (CHAR CMD [] [256], INT PCOUNT); Void SetASCII (Char CMD [] [256], INT PCOUNT); Void Quit (Char CMD [】 [256], int pcount; void showhelp (char cmd [] [); void test (char cmd [] [256], int pcount); void getfile (Char cmd [] [256] , int pcount; void putfile (CHAR CMD [] [256], int Pcount); int stripcmd (char * s, char cmd [] [[256]); void parsecmd (char * s); int getcmdnum (char * s Int Makereq (Char Type, CHAR * Buffer, Int size); int makeck (unsigned short num, char * buffer, int size); void showsiSInfo ();

Cmdnum cmdlist [] = {{"Help", 1, 0, showhelp}, {"exit", 2, 0, quit}, {"TEST", 3, 0, test}, {"get", 4, 1 Getfile}, {"put", 5, 2, putfile}, {"octet", 6, 0, setock}, {"ASCII", 7, 0, setascii}, {"connect", 8, 1, connection }};

Char * helptext = "Help: show this text / n / EXIT: EXIT PRAGRAM / N / CTET: SET FILE MODE TO OCTET / N / ASCII: SET File Mode to Netascii / N / Connect Remoteip: Connect To Server / N / Get FileName: GET File from Server / N / Put LocalName RemoteFileName: Upload File to Server / N ";

SOCKET sock = INVALID_SOCKET; char desthost [256] = "127.0.0.1"; int filemode = TFTP_NETASCII; int main (int argc, char * argv []) {char cmd [256]; WSADATA stWSAData; int ret = 0; sockaddr_in Addr; ShowsysInfo (); IF (WSAStartup (WSA_Version, & Stwsadata)! = 0) {Printf ("can't start socket / n"); exit (0);} SOCK = Socket (PF_INET, SOCK_DGRAM, 0); if (SOCK == invalid_socket) {Printf ("can't create socket / n"); exit (0);} addr.sin_family = pf_inet; addr.sin_port = INADDR_ADDR = INADDR_ADDR.S_ADDR = INADDR_Addr; if (Bind SOCK, STRUCKADDR *) & addr, sizeof (addr))! = 0) {Printf ("can't bind socket / n"); exit (0);} while (true) {fflush (stdin); printf "#"); Gets (cmd); parsecmd (cmd);

Return 0;}

Void showsysInfo () {Printf ("TFTP Client Version 1.0 / N");

} int stripcmd (char * s) {INT i = 0; char * token = null; char seps [] = ", / t / n"; token = STRTOK (S, SEPS); While (token! = null) {IF (i> 2) Break; strcpy (cmd [i], token); token = strtok (null, seps); i ;} return i;} int getcmdnum (char * s) { INT i = 0; for (i = 0; i

Void Parsecmd (Char * S) {Char CMD [3] [256]; int pcount = 0; int Num = -1; pcount = stripcmd (s, cmd); Num = getCmdnum (cmd [0]); if (NUM == - 1) {Printf ("No Such Commond / N"); return;} else {cmdlist [Num] .callback (cmd, pcount-1);}}

Void Quit (CHAR CMD [】 [256], int pcount) {Printf ("exit to system / n"); ClosSocket (SOCK); exit (0);}

Void Showhelp (CHAR CMD [] [256], INT PCOUNT) {Printf (Helptext);} Void Test (Char CMD [] [256], int pcount) {}

Void SetOCTET (CHAR CMD [] [256], INT PCOUNT) {filemode = tftp_ocTet; Printf ("set file mode to octet / n");}

Void Setascii (Char CMD [] [256], INT PCOUNT) {filemode = tftp_netascii; Printf ("Set File Mode To Netascii / N");}

Void ConnectTo (Char CMD [] [("USAGE: Connect Remoteip / N"); Return;} STRCPY (DESTHOST, CMD [1]);}

INT Makeck (unsigned short num, char * buffer, int size) {int pos = 0; buffer [pOS] = 0; POS ; buffer [POS] = TFTP_ACK; POS ; buffer [POS] = (NUM >> 8); POS ; buffer [POS] = (char) NUM; POS ; Return Pos;

INT Makereq (Char Type, CHAR * Buffer, INT Size {INT POS = 0; Unsigned INT i = 0; CHAR S [32] = ""; if (Mode == TFTP_Netascii) STRCPY s, "Netascii"); Else Strcpy (S, "OCTET"); Buffer [POS] = 0; POS ; Buffer [POS] = Type; POS ; for (i = 0; i

INT Makedata (int Num, Char * Data, int buffs) {int pos = 0; buffer [pOS] = 0; POS ; buffer [POS] = TFTP_DATA; POS ; Buffer [POS] = CHAR) (NUM >> 8); POS ; buffer [POS] = (char) NUM; POS ; Memcpy (& Buffer [POS], DATA, DATASIZE); POS = POS DATASIZE; RETURN POS

}

Void getFile (Char cmd [] () {char sendbuf [1024] = {0}; char recvbuf [1024] = {0}; SockAddr_in addr; intenddr_in from; int.comlen = 0; int RET = 0 ; Int LEN = 0; fd_set fdr; int RETRY = 0; struct timeval timeout = {5, 0}; int stat = 0; int lastdata = 0; file * file; int flen = 0; INT C; if = 1) {Printf ("usage: get filename / n"); return;} if ((file = fopen (cmd [1], "r"))))! = Null) {printf ("File% s already EXITS, OVERWRITE? Y / N ", CMD [1]); While (TRUE) {c = getCH (); if ('y' == TouPper (c)) {printf (" / n "); fclose (file); Break;} else if ('n' == Toupper (c)) {printf ("/ n"); fclose (file); return;}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}}} b ")) == null) {Printf (" can't create file / n "); return;} len = Makereq (TFTP_RRQ, FileMode, CMD [1], SendBuf, Sizeof (Sendbuf)); addr.sin_family = Pf_inet; from.sin_family = pf_inet; addr.sin_port = htons (69); addr.sin_addr.s_addr = inet_addr (desthost); Ret = Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, s Izeof (addr); while {fd_zero (& fdr); fd_set (sock, & fdr); RET = SELECT (SOCK, & FDR, NULL, NULL, & TIMEOUT); if (Socket_ERROR == RET) {Printf ("Socket Error / N "); fclose (file);} else if (0 == RET) {f (max_retry == Retry) {printf (" time out / n "); fclose (file); return;} sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr)); Retry ;} else {if (fd_isset (sock, & fdr)) {Retry = 0; fromlen = sizeof (SockAddr);

RET = Recvfrom (Sock, Recvbuf, SizeOf (Recvbuf), 0, (SockAddr *) & from, & fromLomlen; IF (TFTP_ERROR == Recvbuf [1]) {fclose (file); Printf ("Error% D:% S / N ", Recvbuf [3], & Recvbuf [4]); RETURN;} if (0 == STAT) {addr.sin_port = from.sin_port; stat = 1;} if (tftp_data == recvbuf [1]) {LastData = Recvbuf [2] * 256 recvbuf [3]; len = makeck (Lastdata, Sendbuf, Sizeof (SENDBUF)); Sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr); if (RET

Void Putfile (CHAR CMD []) {25}; char recvbuf [1024] = {0}; char DATABUF [1024] = {0}; sockaddr_in addr; SockAddr_in from ; Int = 0; int LEN = 0; fd_set fdr; int RETRY = 0; struct timeVal timeout = {5, 0}; int stat = tftp_wstat_firstack; int laastack = 0; file * file; int Flen = 0; int blocknum = 0; size_t rlen = 0; if (pcount! = 2) {Printf ("USAGE: PUT LOCALFILENAME RemoteFileName / N"); Return;} IF ((file = fopen (cmd [1], " R ")) == NULL) {Printf (" File% s Not Found / N ", CMD [1]); Return;} len = Makereq (TFTP_WRQ, FileMode, CMD [2], Sendbuf, Sizeof (Sendbuf)) Addr.sin_family = pf_inet; addr.sin_port = htons (69); addr.sin_addr.s_addr = inet_addr (desthost); Ret = Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr)) ; If (File = FOPEN (CMD [1], "R")) == NULL) {Printf ("can't open file% s / n", cmd [1]); return;} while (TRUE) {FD_ZERO (& FDR); FD_SET (SOCK, & FDR); RET = SELECT (Sock, & FDR, NULL, NULL, & TIMEOUT); if (S Ocket_ERROR == RET) {Printf ("socket error / n"); fclose (file); return;} else if (0 == RET) {if (max_retry == retry) {Printf ("time out / n") Fclose (file);} Sendto (SOCK, SENDBUF, LEN, 0, (SockAddr *) & addr, sizeof (addr)); Retry ;} else {RETRY = 0; fromlen = sizeof (sockaddr); return = recvfrom (SOCK, RECVBUF, 0, (SOCKADDR *) & from, & fromLen; if (tftp_error == recvbuf [1]) {fclose (file); Printf ("Error% D:% S / N"

, RECVBUF [3], & Recvbuf [4]); RETURN;} if (tftp_ack == recvbuf [1]) {Lastack = Recvbuf [2] * 256 recvbuf [3]; switch (stat) {copy tftp_wstat_firstack: IF ( 0 == lastack) {stat = tftp_wstat_nextack; addr.sin_port = from.sin_port; rlen = fread (DatabaseF, 1,512, file); flen = flen rlen; if (rlen <512 && feof (file) {stat = tftp_wstat_lastack } Else if (File) {Printf ("Error: Read file / N"); fclose (file); Return;} block ; len = makedata (blockdata (blockdata (blockdata (block, sizeof (sendbuf)) Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr)); Printf ("% D Byte Send / R", Flen);} else {fclose (file); Printf ("Error Ack Number "); return;} Break; case tftp_wstat_nextack: IF (Lastack == Blocknum) {rlen = fread (DataBuf, 1,512, file); flen = flen rlen; IF (RLLEN <512 && Feof (file) {stat = tftp_wstat_lastack;} else if (File) {Printf ("Error: Read file / n"); fclose (file); return;} boxNum ; len = Makedata (Blocknum, DataBuf, Rlen, Sendbuf, Sizeof (Sendbuf); Sendto (Sock, Sendbuf, Len, 0, (SockAddr *) & addr, sizeof (addr); Printf ("% D Byte Send / R", Flen } Else {fclose (file); Printf ("Error Ack Number"); Return;} Break; Case TFTP_WSTAT_LASTACK: IF (Lastack ==