FTP Server
A. Third Edition
This is almost the perfect edition that I can make except that some strange behaviour happens when you try to
transfer file of size bigger than 1M. I highly suspect it is due to the size of buffer of windows socket. The
lab instructor agrees to my opinion.
Here it comes...
Hi Nick, I encountered the same error before. Try to run WSAGetLastError() to see the code of error you get. I also think that it is due to the receiver buffer. Unfortunately, as far as I know, there is no way to adjust the buffer size since this is in another layer. You may try to slow the sending process a little bit or to increase the packet size from 128 up to 1024. Also, a log file on both sides may help you to figure out what is happening. If you a doing this, you have to close it after each writing process and open it again, otherwise you will lose all the data in case of program failure. Anyway, don't panic, if all other requirements are accomplished, this will not significantly affect your mark.
Here it goes...
Here it comes...
> Hi Nick,
>
> it is very interesting what you have found about this strange "network
noise".
> Do you have the same "noise" in the lab? Since at home they might be some
> programs or spies which are trying to connect to your port, at school they
must
> be filtered by the server. Please let me know if you trace down such "UFO"
> packets in H905. If yes, could you store them in a file (files)? It would
be
> interesting to take a look inside them.
> Anyway, good that you have solved the problem.
>
> Thanks,
Here it goes...
Yes, it seems positive that some "spy" program is residing in my
roommate's
computer. You see, when I transfer file from my computer to his computer, I
traced these "noise" which apparently communicating with same port in his
computer. However, when the direction changed, that is when I transfer file
from his computer to my computer, it is quiet. You see, I install
"anti-virus" and a "spysweeper" which will sweep my spywares. So, it is
clean in my computer and I hear no noise coming in or out of my computer.
In Lab H905, it is also quiet even though occasionally I have problem of
disk quota when I transfer file of size of more than 20M.
I record the noise in log file. However, it is almost useless since I don't
know the format. In VC6 debugger, I try to read the message. But it is
definitely not any simple text or system message because it is so frequent.
Enclosed the two logs are for your reference.
Thank you and by the way, should I submit the code file to you?
see you tomorrow,
In network, a client program may request files to be put to or get from server program. You have to use the
socket to implement with a basic file transfer protocol by your own.
/********************************************************************************
features:
1. all data and command are sent in a data unit of "packet" (see packet.h)
2. socket transimission function are similar in both server and client side, so,
I decide to write socket as a single class just like "delphi".
3. socket is closed at both client and server side after each file transmission.
4. robust error handling mechnism combined with "exception" handling.
a) file name is checked before send out request.
b) empty file doesn't allow to be sent.
c) when a packet of type of "ErrorType" is received, exception is thrown.
d) when file open error occurs, an "ErrorType" packet is sent to remote host
to
abort current operation along with error no message so that remote host
can display error information accordingly.
********************************************************************************/
/*********************************************************************************
file transmission protocol:
1. put file:
a) Client sends an outgoing packet of "type" of "PutType" to start. The
"data" field stores
the file name to be sent, "tail" field stores the size of file. The
offset of a
constant number of bytes in "data" field also stores the "user ID".
b) Server replies an outgoing packet of type of "PutReplyType" by copying
incoming packet to
confirm.
c) Client starts sending data packet till end of file.
d) Client sends out a packet of type of "EOFType" to indicate end of
transimission even
though server already gets file size from first packet.
2. get file:
a) Client sends an outgoing packet of "type" of "GetType" to start. The
"data" field stores
the file name to be sent, "tail" field stores the size of file. The
offset of a
constant number of bytes in "data" field also stores the "user ID".
b) Server replies an outgoing packet of type of "GetReplyType" by copying
incoming packet to
confirm.
c) Server starts sending data packet till end of file.
d) Server sends out a packet of type of "EOFType" to indicate end of
transimission even
though server already gets file size from first packet.
*********************************************************************************/
E.Further improvement
It is said that TCP/IP won't lose packet of transfer, but I just continually plan to re-implement this functionality
F.File listing
project client:
1. error.h
2. error.cpp
3. log.h
4. log.cpp
5. packet.h
6. socket.h
7. socket.cpp
8. client.cpp
project server:
1. error.h
2. error.cpp
3. log.h
4. log.cpp
5. packet.h
6. socket.h
7. socket.cpp
8. server.cpp
workspace setup:
1. create an empty "workspace".
2. copy all above source code under the workspace.
3. "new" a project named "client" by "add to current workspace".
4. "new" a project named "server" by "add to current workspace".
5. switch between two project and from "project" menu "add files" to project.
6. in "project" menu choose "setting" and "link", add "wsock32.lib" at end.
By doing above, you don't have to modify the "file path" of all head files.
file name: error.h
#ifndef ERROR_H #define ERROR_H #include <stdio.h> #include <stdlib.h> #include "log.h" const int ErrorNumber=14; const int SeriousProblem=9; #define CANNOT_OPEN_LOG 0 #define CANNOT_START_WSASTARTUP 1 #define GETHOSTNAMEFAILED 2 #define REMOTE_GETHOSTNAME_FAILED 3 #define SOCKET_FAILED 4 #define CONNECT_FAILED 5 #define CANNOT_BIND_SOCKET 6 #define CANNOT_SETUP_LISTEN 7 #define CONNECTION_INTERRUPT 8 #define CANNOT_OPEN_FILE_FOR_PUT 9 #define CANNOT_OPEN_FILE_FOR_GET 10 #define WAIT_TIME_OUT 11 #define ERROR_DATA_RCVED 12 #define EMPTY_FILE_TO_BE_SENT 13 static char* errorStrings[ErrorNumber]= { "CANNOT_OPEN_LOG", "Error in starting WSAStartup", "GET HOST NAME FAILED", "GET REMOTE HOST NAME FAILED", "SOCKET_FAILED", "CONNECT_FAILED", "CANNOT_BIND_SOCKET", "CANNOT_SETUP_LISTEN", "TRANSMISSION INTERRUPTED UNEXPECTEDLY", "CANNOT_OPEN_FILE_FOR_PUT", "CANNOT_OPEN_FILE_FOR_GET", "WAIT_TIME_OUT", "transmission error happened at remote host", "EMPTY_FILE_TO_BE_SENT", }; struct FTPExcep { int errNo; int remoteErrNo; }; void errorHandler(int errorNo, int remoteErrNo=0); #endif
file name: error.cpp
#include "error.h" #include <stdio.h> #include <stdlib.h> #include <windows.h> void errorHandler(int errorNo, int remoteErrNo) { FTPExcep excep; char errbuf[20]; writeLog(errorStrings[errorNo]); if (errorNo==CONNECTION_INTERRUPT) { sprintf(errbuf, "The last error is %d", WSAGetLastError()); } else { sprintf(errbuf, "The last error is %d", GetLastError()); } writeLog(errbuf, true); excep.errNo=errorNo; //this remoteErrno would be shown at remote host excep.remoteErrNo=remoteErrNo; throw excep; //only the minor error need to be handled with exception /* switch (errorNo) { case REMOTE_GETHOSTNAME_FAILED: case CANNOT_OPEN_FILE_FOR_PUT: case CANNOT_OPEN_FILE_FOR_GET: case WAIT_TIME_OUT: case ERROR_DATA_RCVED: case EMPTY_FILE_TO_BE_SENT: case CONNECT_FAILED: { FTPExcep excep; excep.errNo=errorNo; //this remoteErrno would be shown at remote host excep.remoteErrNo=remoteErrNo; throw excep; } } //default is to exit exit(1); */ }
file name: log.h
#ifndef LOG_H #define LOG_H #include <stdio.h> #include <stdlib.h> #include "error.h" typedef unsigned long ulong; //this will only be called once void startLog(); void closeLog(); //write anything you want ulong writeLog(char* buffer, bool toDisplay=false); #endif
file name: log.cpp
#include "log.h" #include "error.h" #include <time.h> #include <windows.h> const int MaxLogNameLength=20; char logName[MaxLogNameLength]; HANDLE log=NULL; void getTimeStamp(char* buf); void getTimeStamp(char* buf) { char timeBuf[128]; _strtime(timeBuf); strcpy(buf, timeBuf); strcat(buf, " "); _strdate(timeBuf); strcat(buf, timeBuf); } void closeLog() { CloseHandle(log); } //this should be called only once void startLog() { //getTimeStamp(logName); //strcat(logName, timeBuf); //sprintf(logName, "%u", time(0)); //this should be called only once, so.... if (log==NULL) { strcpy(logName, "log"); strcat(logName, ".txt"); if ((log=CreateFile(logName, GENERIC_WRITE, 0, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL))==INVALID_HANDLE_VALUE) { errorHandler(CANNOT_OPEN_LOG); } } } ulong writeLog(char* buffer, bool toDisplay) { char timeBuf[128]; //long distance; ulong result, temp; getTimeStamp(timeBuf); strcat(timeBuf, ":\t"); //GetFileSize(log, &distance); SetFilePointer(log, 0, NULL, FILE_END); WriteFile(log, timeBuf, strlen(timeBuf), &result, NULL); WriteFile(log, buffer, strlen(buffer), &result, NULL); if (toDisplay) { printf("%s\n", buffer); } //strcpy(timeBuf, "\n"); timeBuf[0]=13; timeBuf[1]=10; timeBuf[2]=0; WriteFile(log, timeBuf, strlen(timeBuf), &temp, NULL); return result; }
file name: packet.h
#ifndef PACKET_H #define PACKET_H typedef unsigned short ushort; const int PacketDataSize=120; /* //if it is command, the "data" is the command string #define COMMAND 0x01 //if it is information, "data" contains "filename", //"tail" contains the file size. #define INFORMATION 0x02 //if it is data, "data" contains data, and "tail" contains "index" #define DATATYPE 0x03 //since we have the file size at "negotiation, we don't need sign of eof //but we have error which contains error msg in "data" #define ERRORTYPE 0x04 */ //all size indicates the length of "data" field of struct packet //get contains the file name as "data", size of file as "tail" #define GETTYPE '1' //put contains the file name as data, size of file as tail #define PUTTYPE '2' //get reply just acknowledge the get information, the file name is in data, plus file size in tail #define GETREPLYTYPE '3' //just reply to put, and file name is still in the data. #define PUTREPLYTYPE '4' //whenever anything goes wrong #define ERRORTYPE '5' //the size of data is contained in size, in tail, it may contains the index number of packet #define DATATYPE '6' //this is a special packet, the data may also contains "data" #define EOFTYPE '7' struct Packet { ushort type; ushort size; unsigned long tail; char data[PacketDataSize]; }; #endif
file name: socket.h
#ifndef SOCKET_H #define SOCKET_H #include <winsock.h> #include "packet.h" #include "error.h" #define REQUEST_PORT 0x7070 //int port=REQUEST_PORT; const int MessageBufferSize=128; const int SecondStart=100; class Socket { private: union { struct sockaddr generic; struct sockaddr_in ca_in; }ca; //socket data types fd_set readfds; bool bServer; int port; SOCKET s, ser; SOCKADDR_IN sa; // filled by bind SOCKADDR_IN sa_in; // fill with server info, IP, port HOSTENT *hp; HOSTENT *rp; WSADATA wsadata; char buffer[128]; HANDLE hfile; void writeToLog(bool toDisplay=false); void initialize(); void serverConn(); void recvFile(unsigned long fileSize); void sendFile(unsigned long fileSize); void connectTo(char* serverName); public: char localhost[11]; char remotehost[11]; void clientConn(char* serverName); Packet incoming, outgoing; char msg[256]; void closeFile(); void exceptionHandler(const FTPExcep& excep); ~Socket(); Socket(bool isServer=false); void listening(); int sendPacket(const Packet& packet); int recvPacket(Packet& packet); int sendMsg(); int recvMsg(); void tranFile(Packet& packet); }; #endif
file name: socket.cpp
/******************************************************************************* *socket.h encapsulate socket functions and can act as both client and server *author: Huang, Qingzhe(Nick), ID: 5037735 GUAN, Huihua(Angel), ID:4778375 *date: Sep. 16, 2004 * * * ********************************************************************************/ /******************************************************************************** features: 1. all data and command are sent in a data unit of "packet" (see packet.h) 2. socket transimission function are similar in both server and client side, so, I decide to write socket as a single class just like "delphi". 3. socket is closed at both client and server side after each file transmission. 4. robust error handling mechnism combined with "exception" handling. a) file name is checked before send out request. b) empty file doesn't allow to be sent. c) when a packet of type of "ErrorType" is received, exception is thrown. d) when file open error occurs, an "ErrorType" packet is sent to remote host to abort current operation along with error no message so that remote host can display error information accordingly. ********************************************************************************/ /********************************************************************************* file transmission protocol: 1. put file: a) Client sends an outgoing packet of "type" of "PutType" to start. The "data" field stores the file name to be sent, "tail" field stores the size of file. The offset of a constant number of bytes in "data" field also stores the "user ID". b) Server replies an outgoing packet of type of "PutReplyType" by copying incoming packet to confirm. c) Client starts sending data packet till end of file. d) Client sends out a packet of type of "EOFType" to indicate end of transimission even though server already gets file size from first packet. 2. get file: a) Client sends an outgoing packet of "type" of "GetType" to start. The "data" field stores the file name to be sent, "tail" field stores the size of file. The offset of a constant number of bytes in "data" field also stores the "user ID". b) Server replies an outgoing packet of type of "GetReplyType" by copying incoming packet to confirm. c) Server starts sending data packet till end of file. d) Server sends out a packet of type of "EOFType" to indicate end of transimission even though server already gets file size from first packet. *********************************************************************************/ #include <winsock2.h> #include <time.h> #include "socket.h" #include <string.h> #include "log.h" #include "error.h" #include "packet.h" const long TimeOutLimit=10; const int ErrorLimit=40; char msgbuf[128]; //add a little indicator of ">" to indicating the progress of file transfer void Socket::sendFile(unsigned long fileSize) { int counter=0, times2print=fileSize/PacketDataSize; bool begin=false; if (times2print>80) { //divide job into 80 slots and print 1 ">" every slot times2print=times2print/80; } else { //otherwise, print everytime times2print=1; } while (ReadFile(hfile, outgoing.data, PacketDataSize, (LPDWORD)&outgoing.size, NULL) &&outgoing.size!=0) { outgoing.type=DATATYPE; sendPacket(outgoing); if (!begin) { begin=true; sprintf(msgbuf, "Begin sending first byte from \"%s\"\n", remotehost); writeLog(msgbuf, true); } counter++; if (counter==times2print) { counter=0; printf(">"); } } outgoing.type=EOFTYPE; sendPacket(outgoing); sprintf(msgbuf, "End of transmission to \"%s\"\n", remotehost); writeLog(msgbuf, true); sprintf(msgbuf, "Succeed sending total %d bytes\n", fileSize); writeLog(msgbuf, true); CloseHandle(hfile); closesocket(s); } void Socket::recvFile(unsigned long fileSize) { double number; int counter=0, times2print=fileSize/PacketDataSize; bool begin=false; //divide into 80 times for printing progress if (times2print>80) { times2print=times2print/80; } else { //otherwise, print everytime times2print=1; } while (true) { if (recvPacket(incoming)>0) { if (incoming.type==DATATYPE) { if (!begin) { begin=true; sprintf(msgbuf, "Begin recieving first byte from \"%s\"\n", remotehost); writeLog(msgbuf, true); } WriteFile(hfile, incoming.data, (DWORD)(incoming.size), (LPDWORD)&number, NULL); counter++; if (counter==times2print) { counter=0; printf(">"); } } else { if (incoming.type==EOFTYPE) { sprintf(msgbuf, "End of transmission from \"%s\"\n", remotehost); writeLog(msgbuf, true); break; } else { if (incoming.type<EOFTYPE) { errorHandler(ERROR_DATA_RCVED); } //ELSE JUST PRETEND IGNORE } } } } if (SetEndOfFile(hfile)>0) { sprintf(msgbuf, "Succeed receiving total %d bytes\n", fileSize); writeLog(msgbuf, true); } CloseHandle(hfile); closesocket(s); } void Socket::closeFile() { CloseHandle(hfile); hfile=NULL; } void Socket::tranFile(Packet& packet) { if (!bServer) { //for client, these are to be sent switch(packet.type) { case PUTTYPE: sprintf(msgbuf, "prepare to send file \"%s\"", packet.data); writeLog(msgbuf); if ((hfile=CreateFile(packet.data, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, 0))==INVALID_HANDLE_VALUE) { //if cannot open file, then nothing is sent. errorHandler(CANNOT_OPEN_FILE_FOR_PUT); //packet.type=ERRORTYPE; //packet.tail=CANNOT_OPEN_FILE_FOR_PUT; } else { packet.tail=GetFileSize(hfile, NULL); if (packet.tail==0) { errorHandler(EMPTY_FILE_TO_BE_SENT); } unsigned long nameLen=PacketDataSize-SecondStart-1; //char temp[256]; GetUserName(packet.data+SecondStart, &nameLen); //GetUserName(temp, &nameLen); //int ok=GetLastError(); sendPacket(packet); //for client have to wait for reply long start=time(0); do { if (time(0)-start>TimeOutLimit) { errorHandler(WAIT_TIME_OUT); } recvPacket(incoming); //error happened at server side if (incoming.type==ERRORTYPE) { //so, here we got the error no from remote host errorHandler(ERROR_DATA_RCVED, incoming.tail); } }while (incoming.type!=PUTREPLYTYPE); sendFile(packet.tail); } break; case GETTYPE: sprintf(msgbuf, "prepare to receive file \"%s\"", packet.data); writeLog(msgbuf); if ((hfile=CreateFile(packet.data, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, 0))==INVALID_HANDLE_VALUE) { //if cannot open file, then nothing is sent errorHandler(CANNOT_OPEN_FILE_FOR_GET); } else { //send out the request unsigned long nameLen=PacketDataSize-SecondStart-1; GetUserName(packet.data+SecondStart, &nameLen); sendPacket(packet); long start=time(0); do { if (time(0)-start>TimeOutLimit) { errorHandler(WAIT_TIME_OUT); } recvPacket(incoming); //error happened at server side if (incoming.type==ERRORTYPE) { errorHandler(ERROR_DATA_RCVED, incoming.tail); } }while (incoming.type!=GETREPLYTYPE); recvFile(incoming.tail); } break; } } else { //for server, this is to be replied switch (packet.type) { case PUTTYPE: //strncpy(fileName, packet.data, packet.size); sprintf(msgbuf, "User \"%s\" at host \"%s\" requested file \"%s\" to be received.\n", packet.data+SecondStart, remotehost, packet.data); writeLog(msgbuf, true); printf("Prepare receiving file from \"%s\", waiting...\n", remotehost); if ((hfile=CreateFile(packet.data, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, 0))==INVALID_HANDLE_VALUE) { //if cannot open file, then nothing is sent. errorHandler(CANNOT_OPEN_FILE_FOR_PUT); //packet.type=ERRORTYPE; //packet.tail=CANNOT_OPEN_FILE_FOR_PUT; } else { //GetFileSize(hfile, &packet.tail); //this is to reply put request outgoing.type=PUTREPLYTYPE; outgoing.size=packet.size; strncpy(outgoing.data, packet.data, packet.size); outgoing.tail=packet.tail; sendPacket(outgoing); //pass size of file as param recvFile(outgoing.tail); } break; case GETTYPE: sprintf(msgbuf, "User \"%s\" at host \"%s\" requested file \"%s\" to be send.\n", packet.data+SecondStart, remotehost, packet.data); writeLog(msgbuf, true); printf("Prepare sending file to \"%s\", waiting...\n", remotehost); //strncpy(fileName, packet.data, packet.size); if ((hfile=CreateFile(packet.data, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, 0))==INVALID_HANDLE_VALUE) { //if cannot open file, then nothing is sent errorHandler(CANNOT_OPEN_FILE_FOR_GET); } else { //send out the request outgoing.type=GETREPLYTYPE; outgoing.size=packet.size; strncpy(outgoing.data, packet.data, packet.size); outgoing.tail=GetFileSize(hfile, NULL); //file size is param // sendPacket(outgoing); sendFile(outgoing.tail); } break; } } } //exception handling is only to send error packet out if it is //local error. For remote error, you simply display it. //in previous version, I send everything, it is meaningless. void Socket::exceptionHandler(const FTPExcep& excep) { sprintf(msgbuf, "Unexpected error of \"%s\" happened\n", errorStrings[excep.errNo]); writeLog(msgbuf, true); closeFile(); if (excep.errNo==ERROR_DATA_RCVED) { //it is remote error, just show the message sprintf(msgbuf, "remote host error \"%s\" happened\n", errorStrings[excep.remoteErrNo]); writeLog(msgbuf, true); } //if (excep.errNo else { if (excep.errNo>=SeriousProblem) { //if it is local error, we need to notify remote. outgoing.type=ERRORTYPE; outgoing.tail=excep.errNo; //an error packet must be sent out, otherwise remote host will be freezed sendPacket(outgoing); } } } void Socket::writeToLog(bool toDisplay) { writeLog(buffer, toDisplay); /* << "wsadata.wVersion " << wsadata.wVersion << endl << "wsadata.wHighVersion " << wsadata.wHighVersion << endl << "wsadata.szDescription " << wsadata.szDescription << endl << "wsadata.szSystemStatus " << wsadata.szSystemStatus << endl << "wsadata.iMaxSockets " << wsadata.iMaxSockets << endl << "wsadata.iMaxUdpDg " << wsadata.iMaxUdpDg << endl; */ } int Socket::sendPacket(const Packet& packet) { int result=0; int counter=0; while ((result=send(s, (char*)(&packet), sizeof(Packet), 0))==SOCKET_ERROR) { Sleep(10); counter++; if (counter==ErrorLimit) { errorHandler(CONNECTION_INTERRUPT); } } return result; } int Socket::recvPacket(Packet& packet) { int result=0; int counter=0; while ((result=recv(s, (char*)(&packet), sizeof(Packet), 0))==SOCKET_ERROR) { counter++; if (counter==ErrorLimit) { errorHandler(CONNECTION_INTERRUPT); } } return result; } int Socket::sendMsg() { int result=0; result=send(s, msg, strlen(msg), 0); return result; } int Socket::recvMsg() { int result=0; msg[0]='\0'; result=recv(s, msg, MessageBufferSize, 0); msg[result]='\0'; return result; } void Socket::connectTo(char* serverName) { strcpy(remotehost, serverName); sprintf(buffer, "Remote host name is: \"%s\"", remotehost); writeToLog(); if((rp=gethostbyname(remotehost)) == NULL) { //throw "remote gethostbyname failed\n"; errorHandler(REMOTE_GETHOSTNAME_FAILED); } /* For UDP protocol replace SOCK_STREAM with SOCK_DGRAM */ //Specify server address for client to connect to server. memset(&sa_in,0,sizeof(sa_in)); memcpy(&sa_in.sin_addr,rp->h_addr,rp->h_length); sa_in.sin_family = rp->h_addrtype; sa_in.sin_port = htons(port); //Display the host machine internet address sprintf(buffer, "Connecting to remote host:%s\n", inet_ntoa(sa_in.sin_addr)); writeLog(buffer); //Connect Client to the server if (connect(s,(LPSOCKADDR)&sa_in,sizeof(sa_in)) == SOCKET_ERROR) //throw "connect failed\n"; { errorHandler(CONNECT_FAILED); } } void Socket::clientConn(char* serverName) { if((s = socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET) //throw "Socket failed\n"; { errorHandler(SOCKET_FAILED); } connectTo(serverName); } void Socket::serverConn() { if((ser = socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET) //throw "Socket failed\n"; { errorHandler(SOCKET_FAILED); } //Fill-in Server Port and Address info. sa.sin_family = AF_INET; sa.sin_port = htons(port); sa.sin_addr.s_addr = htonl(INADDR_ANY); //Bind the server port if (bind(ser,(LPSOCKADDR)&sa,sizeof(sa)) == SOCKET_ERROR) { errorHandler(CANNOT_BIND_SOCKET); //throw "can't bind the socket"; } sprintf(buffer, "bind is successful\n"); writeToLog(); //Successfull bind, now listen for client requests. sprintf(buffer, "Ftp server starting at host:[%s]\n", localhost); writeLog(buffer, true); sprintf(buffer, "Waiting to be contacted for transferring files..."); writeLog(buffer, true); //listening(); } void Socket::listening() { int infds=1, outfds=0;//, outNum, inNum; int calen=sizeof(ca); struct timeval timeout; hostent* phost; if(listen(ser,10) == SOCKET_ERROR) { errorHandler(CANNOT_SETUP_LISTEN); } // throw "couldn't set up listen on socket"; else { sprintf(buffer, "Listen was successful\n"); writeToLog(); } const struct timeval *tp=&timeout; FD_ZERO(&readfds); //wait loop while(true) { FD_SET(ser,&readfds); //always check the listener if(!(outfds=select(infds,&readfds,NULL,NULL,tp))) {} else if (outfds == SOCKET_ERROR) throw "failure in Select"; else if (FD_ISSET(ser,&readfds)) { //cout << "got a connection request" << endl; sprintf(buffer, "got a connection request\n"); writeToLog(); } //Found a connection request, try to accept. if((s=accept(ser,&ca.generic,&calen))==INVALID_SOCKET) { throw "Couldn't accept connection\n"; } else { sprintf(buffer, "accepted connection from %s %d\n", inet_ntoa(ca.ca_in.sin_addr), htons(ca.ca_in.sin_port)); //calen=sizeof(ca); //getpeername(s, &ca.generic, &calen); //printf("generic.data %s,\n", ca.generic.sa_data); phost=gethostbyaddr((char*)&ca.ca_in.sin_addr, sizeof(ca.ca_in.sin_addr), AF_INET); //printf("%s\n", phost->h_name); strcpy(remotehost, phost->h_name); writeToLog(); break; } /* if ((inNum=recvMsg())>0) { printf("message from client %s\n", msg); } if ((outNum=sendMsg())>0) { printf("message to client %s\n", msg); } */ } } Socket::~Socket() { closeLog(); closesocket(s); if (bServer) { closesocket(ser); } WSACleanup(); } Socket::Socket(bool isServer) { initialize(); bServer=isServer; if (!isServer)//CLIENT { //clientConn(); } else { serverConn(); } } void Socket::initialize() { startLog(); port=REQUEST_PORT; if (WSAStartup(0x0202,&wsadata)!=0) { errorHandler(CANNOT_START_WSASTARTUP); } else { strcpy(buffer, "WSAStartup was successful\n"); writeToLog(false); sprintf(buffer, "%s %d\n", "wsadata.wVersion ", wsadata.wVersion); writeToLog(false); sprintf(buffer, "%s %d\n", "wsadata.wVersion ", wsadata.wHighVersion); writeToLog(false); sprintf(buffer, "%s %s\n", "wsadata.szDescription ", wsadata.szDescription); writeToLog(false); sprintf(buffer, "%s %s\n", "wsadata.szSystemStatus ", wsadata.szSystemStatus); writeToLog(false); sprintf(buffer, "%s %d\n", "wsadata.iMaxSockets ", wsadata.iMaxSockets); writeToLog(false); sprintf(buffer, "%s %d\n", "wsadata.iMaxUdpDg ", wsadata.iMaxUdpDg); writeToLog(false); //WriteFile(test,buffer,sizeof(buffer),&dwtest,NULL); } //Display name of local host. gethostname(localhost,10); /* sprintf(buffer, "%s%s%s\n", "server starting on host [", localhost, "]"); writeToLog(true); sprintf(buffer, "Waiting to be contacted for transferring files..."); writeToLog(true); */ if((hp=gethostbyname(localhost)) == NULL) //throw "gethostbyname failed\n"; { errorHandler(GETHOSTNAMEFAILED); } //Create the socket }
file name: client.cpp
/* send and receive codes between client and server */ /* This is your basic WINSOCK shell */ #include <stdio.h> #include <stdlib.h> #include "socket.h" #include "packet.h" #include "log.h" #include "error.h" //reference for used structures /* * Host structure struct hostent { char FAR * h_name; official name of host * char FAR * FAR * h_aliases; alias list * short h_addrtype; host address type * short h_length; length of address * char FAR * FAR * h_addr_list; list of addresses * #define h_addr h_addr_list[0] address, for backward compat * }; * Socket address structure struct sockaddr_in { short sin_family; u_short sin_port; struct in_addr sin_addr; char sin_zero[8]; }; */ int main() { char msgbuf[20]; char serverName[10]; Socket client; while (true) { printf("\n%s", "Type name of ftp server(quit for exit):"); //Ask for name of remote server scanf("%s", serverName); if (strcmp(serverName, "quit")==0) { break; } try { client.clientConn(serverName); printf("\nType name of file to be transferred:"); //strcpy(client.outgoing.data, "nicktest.txt"); scanf("%s", client.outgoing.data); //packet.type=packet.type-'0';//change to client.outgoing.size=strlen(client.outgoing.data); printf("Type direction of transfer:( get ; put)"); //client.outgoing.type='2'; scanf("%s", msgbuf); if (strcmp(msgbuf, "get")==0) { client.outgoing.type=GETTYPE; } else { client.outgoing.type=PUTTYPE; } printf("Sent request to %s, waiting...\n", serverName); client.tranFile(client.outgoing); } catch (FTPExcep excep) { /* printf("Unexpected error of \"%s\" happened\n", errorStrings[excep.errNo]); client.closeFile(); if (excep.errNo==ERROR_DATA_RCVED) { //it is remote error, just show the message printf("remote host error \"%s\" happened\n", errorStrings[excep.remoteErrNo]); } //if (excep.errNo else { //if it is local error, we need to notify remote. client.outgoing.type=ERRORTYPE; client.outgoing.tail=excep.errNo; //an error packet must be sent out, otherwise remote host will be freezed client.sendPacket(client.outgoing); } */ client.exceptionHandler(excep); } } /* while (true) { //scanf("%s\n", client.msg); printf("type your message:"); //gets(msgbuf); //scanf("type:%c\ndata:%s\n", &type, msgbuf); //sprintf(&client.msg[1], "%u", strlen(msgbuf)); //sprintf(&client.msg[sizeof(int)+1], "%s", msgbuf); client.msg[0]=COMMAND; //gets(msgbuf); strcpy(msgbuf, "their is message here"); sprintf(&client.msg[1], "%u", strlen(msgbuf)); sprintf(&client.msg[sizeof(int)+1], "%s", msgbuf); //packet.size=strlen(msgbuf); //packet.tail=0xff; sprintf(&client.msg[PacketDataSize+sizeof(int)+1], "%d", 158); client.sendPacket(); } */ return 0; }
file name: server.cpp
#include "socket.h" #include "packet.h" #include <stdio.h> #include <stdlib.h> #include "error.h" int main() { Socket server(true); //int size, tail; //char type; //char mbuf[128]; //printf("I am waiting...\n"); while (true) { server.listening(); if (server.recvPacket(server.incoming)>0) { //printf("User \"%s\" at host \"%s\" requested file \"%s\" to be transmitted\n", // server.incoming.data+ SecondStart, server.remotehost, server.incoming.data); try { server.tranFile(server.incoming); } //FTPExcep is defined in "error.h" and it is handled in a similar way //by both server-side and client-side catch (FTPExcep excep) { /* printf("Unexpected error \"%s\" happened\n", errorStrings[excep.errNo]); server.closeFile(); server.outgoing.type=ERRORTYPE; server.outgoing.tail=excep.errNo; //should send error info to remote host server.sendPacket(server.outgoing); */ server.exceptionHandler(excep); } printf("Ftp server starting at host:[%s]\n", server.localhost); printf("Waiting to be contacted for transferring files...\n"); } } /* while (true) { if (server.recvMsg()>0) { //printf("message from client:%s\n", server.msg); sscanf(server.msg, "%1c", &type); sscanf(&server.msg[1], "%u", &size); printf("type:%c\nsize:%u\n", type, size); strncpy(mbuf, &server.msg[sizeof(int)+1], size); mbuf[size]='\0'; sscanf(&server.msg[sizeof(int)+1+PacketDataSize], "%u", &tail); printf("data:%s\ntail:%u\n", mbuf, tail); } } */ return 0; }
How to run?
1. run server first.
2. run client and type in computer name of server.
3. type in command "get" or "put" and file name which must be in current file path.