sftp.h

伯克利做的SFTP安全文件传输协议

// sftp.h
// common declarations for SafeTP
// copyright SafeTP Development Group, Inc., 2000  Terms of use are as specified in license.txt
    
#ifndef __SFTP_H
#define __SFTP_H

#include "lineread.h"     // StreamLineReader
#include "socksrc.h"      // SocketInputSource
#include "usercfg.h"      // userConfigDir

#ifdef _MSC_VER
  #pragma warning(disable: 4355) // dob: I'm sick of seeing this warning
#endif

class DataBlock;

enum {
  // this is the port we will listen to for incoming connections; there are
  // two relevant points: (1) <49152 is in the "registered" range, meaning long
  // term use requires IANA approval.  (2) eventually we want to live at
  // port 21, where clients look for ftp, and do so via getservbyname("sftp")
  //  conflict: HP DCE uses 2121.. moving to 2123
  SFTPD_PORT = 2123,

  // this is the port for the real ftpd.  it should be retrieved via
  // getservbyname("ftp"), the same way ftpd decides what to listen to
  // (then root can change ftp's port to something other than 21)
  FTPD_PORT = 21,
};


// define convenient package for socket line readers
class SocketLineReader
  : public SocketInputSource,
    public StreamLineReader {
public:
  SocketLineReader(SOCKET s)
    : SocketInputSource(s),
      StreamLineReader((SocketInputSource&)*this)
        // cast needed because g++ *sucks*
  {}
  
  virtual ~SocketLineReader() {}
    // shut the *hell* up, g++
};


// some shared utility functions

void parsePasvArgument(char const *text,
                       IPAddress &addr, int &port);
  // given text of the form of a reply to PASV (without the reply code),
  // return in addr and port the encoded address and port; throws x_assert
  // if the input is malformed

string constructPortArg(IPAddress addr, int port);
  // construct a string of the form "a,a,a,a,p,p" for PORT or PASV

bool parsePortArgument(char const *p,
                       IPAddress &clientAddress, int &clientPort,
                       string &whyFail);
  // given text of the form of a PORT request (without the "PORT "),
  // return addr and port encoded; returns false and sets 'whyFail' if
  // the input is malformed

void testPortParsing();
  // test routine to validate parsePortArgument() (throws x_assert on failure)


// as a programming convenience, and also to strengthen belief that no
// buffer overrun errors are possible, we will try to do all
// variable-length reads via these fns

void recvAllBlock(SOCKET s, DataBlock &block, int lenToRead);
  // like recvAll(); the block must *already* have enough space allocated
  // (and this is checked)

int recvAllToEOFBlock(SOCKET s, DataBlock &block, int lenToRead);
  // like recvAllToEOF(); block must be big enough; returns # of bytes read


#endif // __SFTP_H