soctcp.c

一个ftp服务器程序

#include "ftpdaemon.h"

int socket_stat( int sock, int tmval )
{
    fd_set readmask;
    struct timeval tv, *ptv = NULL;
    int bytes=0;

    FD_ZERO( &readmask );
    FD_SET( sock, &readmask );
    memset( &tv, 0, sizeof(struct timeval) );

    if ( tmval >= 0 ) {
        tv.tv_sec	= tmval;
        ptv		= &tv;
    }

#ifdef SCO5
    switch ( select(sock+1, (fd_set*)&readmask, (fd_set*)0, (fd_set*)0, ptv) ) {
#else
    switch ( select(sock+1, (int*)&readmask, (int*)0, (int*)0, ptv) ) {
#endif
        case 0: /* socket normal */
            return SS_TIMEDOUT;

        case -1: /* socket abnormal */
	    FTPLOG("select() return -1");
            return SS_BAD;

        default: /* socket has event occur */
            if ( ioctl(sock, FIONREAD, &bytes) < 0 ) {
                return SS_BAD;
            }
            else
                if ( bytes < 0 ) {
                    return SS_CLOSED;
                }
                else
                    return SS_READABLE;
    }
}


int send_nbytes( int sock, char *buf, int len )
{
    int left=len, cnt, sended=0;

    while ( left > 0 )
        switch ( socket_stat(sock, 0) ) {
            case SS_TIMEDOUT:
            case SS_READABLE:
                if ( (cnt=send(sock, buf+sended, left, 0)) <= 0 ) {
		    FTPLOG("[%s:%d] send() error",CurrFILE, CurrLINE);
                    return E_FAIL;
                }

                left   -= cnt;
                sended += cnt;
                break;

            case SS_BAD:
            case SS_CLOSED:
                return E_FAIL;
        }

    return E_SUCC;
}


int recv_nbytes( int sock, char *buf, int len, int tmot )
{
    int left=len, cnt, readed=0;

    while ( left > 0 )
        switch ( socket_stat(sock, tmot) ) {
            case SS_READABLE:
                if ( (cnt=recv(sock, buf+readed, left, 0)) <= 0 ) {
		    FTPLOG("[%s:%d] recv() fail",CurrFILE, CurrLINE);
                    return E_FAIL;
                }

                left   -= cnt;
                readed += cnt;
                break;

            case SS_TIMEDOUT:
            case SS_BAD:
            case SS_CLOSED:
                return E_FAIL;
        }
    return E_SUCC;
}