335.htm

unix高级编程原吗

void sig_end ( int signo ) <br>
{ <br>
    fprintf( stderr, "\n\nsig_end = %d\n", signo ); <br>
    exit( SUCCESS ); <br>

}  /* end of sig_end */ <br>
Sigfunc * signal ( int signo, Sigfunc * func ) <br>
{ <br>
    struct sigaction act, oact; <br>
    act.sa_handler = func; <br>
    sigemptyset( &act.sa_mask ); <br>
    act.sa_flags = 0; <br>
    if ( signo == SIGALRM ) <br>
    { <br>
#ifdef  SA_INTERRUPT <br>
        act.sa_flags |= SA_INTERRUPT;  /* SunOS 4.x */ <br>
#endif <br>
    } <br>
    else <br>
    { <br>
#ifdef  SA_RESTART <br>
        act.sa_flags |= SA_RESTART;  /* SVR4, 44BSD */ <br>
#endif <br>
    } <br>
    if ( sigaction( signo, &act, &oact ) < 0 ) <br>
    { <br>
        return( SIG_ERR ); <br>

    } <br>
    return( oact.sa_handler ); <br>
}  /* end of signal */ <br>
Sigfunc * Signal ( int signo, Sigfunc * func )  /* for our signal() function <br>
 */ <br>
{ <br>
    Sigfunc * sigfunc; <br>
    if ( ( sigfunc = signal( signo, func ) ) == SIG_ERR ) <br>
    { <br>
        perror( "signal" ); <br>
        exit( FAILURE ); <br>
    } <br>
    return( sigfunc ); <br>
}  /* end of Signal */ <br>
int Socket ( int family, int type, int protocol ) <br>
{ <br>
    int n; <br>
    if ( ( n = socket( family, type, protocol ) ) < 0 ) <br>
    { <br>
        perror( "socket" ); <br>
        exit( FAILURE ); <br>
    } <br>
    } <br>
    return( n ); <br>
}  /* end of Socket */ <br>
int synScan ( u_long sourceIp, u_short sourcePort, u_short lowPort, u_short <br>
high <br>
Port, struct sockaddr_in * dest ) <br>
{ <br>
    u_char          packet[ SYNSIZE ]; <br>
    struct iphdr *  ip; <br>
    struct tcphdr * tcp; <br>
    int             j; <br>
    ip  = ( struct iphdr * )packet; <br>
    tcp = ( struct tcphdr * )( packet + sizeof( struct iphdr ) ); <br>
    for ( portIndex = lowPort, j = 0 ; portIndex <= highPort; portIndex++ ) <br>
    { <br>
        dest->sin_port = htons( portIndex ); <br>
        if ( sendSyn( sourceIp, sourcePort, 197704, 0, dest ) < 0 ) <br>
        { <br>
            perror( "sendSyn" ); <br>
            exit( FAILURE ); <br>
        } <br>
        while ( 1 ) <br>
        { <br>
        { <br>
            memset( &packet, 0, SYNSIZE ); <br>
            read( recvSocket, &packet, SYNSIZE ); <br>
            if ( ip->saddr != dest->sin_addr.s_addr ) <br>
            { <br>
                continue; <br>
            } <br>
            if ( ( ntohl( tcp->ack_seq ) != 197705 ) && ( ntohl( tcp->ack_se <br>
q ) <br>
!= 197704 ) ) <br>
            { <br>
                continue; <br>
            } <br>
            /* RST/ACK - No service listening on port. */ <br>
            if ( tcp->rst && tcp->ack ) <br>
            { <br>
                break; <br>
            } <br>
            /* SYN/ACK - Service listening on port. */ <br>
            if ( tcp->ack && tcp->syn ) <br>
            { <br>
                ports[ j ] = ntohs( tcp->source ); <br>
                fprintf( stderr, "portIndex = %d, ports[ %d ] = %d\n", portI <br>

ndex <br>
, j, ports[ j ] ); <br>
                j++; <br>
                break; <br>
            } <br>
        }  /* end of while */ <br>
    }  /* end of for */ <br>
    return( j ); <br>
}  /* end of synScan */ <br>
void terminate ( void ) <br>
{ <br>
    if ( sendSocket != -1 ) <br>
    { <br>
        Close( sendSocket ); <br>
        sendSocket = -1; <br>
    } <br>
    if ( recvSocket != -1 ) <br>
    { <br>
        Close( recvSocket ); <br>
        recvSocket = -1; <br>
    } <br>
    fprintf( stderr, "portIndex = %d\n", portIndex ); <br>

    return; <br>
}  /* end of terminate */ <br>
void usage ( char * arg ) <br>
{ <br>
    fprintf( stderr, " Usage: %s [-c localPort] [-l lowPort] [-h highPort] [ <br>
-s s <br>
erverHost]\n", arg ); <br>
    exit( FAILURE ); <br>
}  /* end of usage */ <br>
int main ( int argc, char * argv[] ) <br>
{ <br>
    int    c, i; <br>
    u_char hostName[257]; <br>
    opterr = 0;  /* don't want getopt() writing to stderr */ <br>
    while ( ( c = getopt( argc, argv, "c:h:l:s:" ) ) != EOF ) <br>
    { <br>
        switch ( c ) <br>
        { <br>
        case 'c': <br>
            clientPort      = ( u_short )strtoul( optarg, NULL, 10 ); <br>
            break; <br>
        case 'h': <br>

            highPort        = ( u_short )strtoul( optarg, NULL, 10 ); <br>
            break; <br>
        case 'l': <br>
            lowPort         = ( u_short )strtoul( optarg, NULL, 10 ); <br>
            break; <br>
        case 's': <br>
            serverIp.s_addr = resolveHost( optarg ); <br>
            break; <br>
        case '?': <br>
            usage( argv[0] ); <br>
            break; <br>
        }  /* end of switch */ <br>
    }  /* end of while */ <br>
    if ( ( ( lowPort < LOWPORT ) || ( lowPort > HIGHPORT ) ) <br>
         || <br>
         ( ( highPort < LOWPORT ) || ( highPort > HIGHPORT ) ) <br>
         || <br>
         ( lowPort > highPort ) ) <br>
    { <br>
        fprintf( stderr, "error: lowPort = %d, highPort = %d\n", lowPort, hi <br>
ghPo <br>
rt ); <br>
rt ); <br>
        exit( FAILURE ); <br>
    } <br>
    if ( serverIp.s_addr == 0 ) <br>
    { <br>
        usage( argv[0] ); <br>
    } <br>
    else <br>
    { <br>
        fprintf( stderr, "The server is [ %s ]\n", inet_ntoa( serverIp ) ); <br>
    } <br>
    if ( gethostname( hostName, 256 ) < 0 ) <br>
    { <br>
        perror( "gethostname" ); <br>
        exit( FAILURE ); <br>
    } <br>
    clientIp.s_addr   = resolveHost( hostName ); <br>
    fprintf( stderr, "The client is [ %s ]\n", inet_ntoa( clientIp ) ); <br>
    /* Fill in dest sockaddr_in structure. */ <br>
    memset( ( char * )&server, 0, sizeof( struct sockaddr_in ) ); <br>
    server.sin_family = AF_INET; <br>
    server.sin_addr   = serverIp; <br>
    for ( i = 1; i < 9; i++ ) <br>

    { <br>
        Signal( i, sig_end ); <br>
    } <br>
    Signal( SIGTERM, sig_end ); <br>
    Atexit( terminate ); <br>
    sendSocket = Socket( PF_INET, SOCK_RAW, IPPROTO_RAW ); <br>
    recvSocket = Socket( PF_INET, SOCK_RAW, IPPROTO_TCP ); <br>
    synScan( clientIp.s_addr, clientPort, lowPort, highPort, &server ); <br>
    return( SUCCESS ); <br>
}  /* end of main */ <br>
/*----------------------------------------------------------------------*/ <br>
-- <br>
:发信人: scz (小四), 信区: Security WWW-POST <br>
:标  题: Re: linuxtcp.c(修改) <br>
:发信站: 武汉白云黄鹤站 (Thu Oct 26 11:25:41 2000) , 站内信件 <br>
【 在 scz (小四) 的大作中提到: 】 <br>
: /* <br>
:  * File   : linuxtcp.c: <br>
昨天想看个tcp hijacking的事情，才发现去年在这里贴的那个syn扫描 <br>
不是单独编译版本，实在是不好意思，修改修改，下面这个可以单独编译 <br>
了。完全是演示atexit()、signal()和raw socket，没有太多实际意义了， <br>
等会我转回木棉socket版去。 <br>
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