Ubuntu 10.04 校园网通插件解决方案（西邮）

以前一直用wine装的网通插件，就是装好后运行ishare_user.exe的那个。最近插件突然不能用了，重装老是在装winpcap那儿报错，没办法，就google了另一个方法。
       （不知道怎么发附件，只好贴源代码了……）
        1.copy下面的源代码，保存成drcom.c（名字其实无所谓）
#include <stdio.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
 
typedef struct _code2 {
    char sign;
    char type;
    short len;
    int id;
    int code0;
    int code1;
}code2;
 
typedef struct _code3 {
    char sign;
    char type;
    short len;
    int id;
    int unk0;
    int code1;
    int unk1;
    int code0;
    int check;
    int unk2;
    char mac[6];
    char dhcp;
    char devtype;
    int ipaddr;
    int netmask;
    char padding[48];
}code3;
 
int waitdata(int hsocket, int time)
{
    fd_set fds;
    struct timeval tv;
 
    FD_ZERO(&fds);
    FD_SET(hsocket,&fds);
    tv.tv_usec = time;
    tv.tv_sec = 0;
    return select(hsocket+1,&fds,NULL,NULL,&tv);
}
 
 
main (int argc, char* argv[])
{
    struct in_addr ip,netmask,ptp;
    char mac[6];
    int hsocket;
    struct ifreq ifr;
    struct sockaddr_in sin;
    struct sockaddr *sa = (struct sockaddr *) &sin;
    int fromlen;
    struct sockaddr_in *sin_ptr;
    u_char *ptr;
    u_long *ptr_long;
    int n;
    int check;
    char c1[] = {7,1,8,0,1,0,0,0};
    code2 c2;
    code3 c3;
    char c4[512];
    int sendlen, recvlen;
    int errorcount,workwell,noticed=0;
 
    printf("\nFree Dr.COM for Linux  v0.3\n  mengxp works,2009 @ xiyou\n  http://www.deadc0de.com/\n\n");

init:
    if ((hsocket = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
    {
        perror( "socket error!");
        return 0;
    }
 
    errorcount = 0;
    strcpy(ifr.ifr_name, "ppp0");
    if (ioctl(hsocket, SIOCGIFADDR, &ifr) < 0)
    {
//        perror("ioctl SIOCGIFADDR error");
        errorcount++;
    }
    sin_ptr = (struct sockaddr_in *)&ifr.ifr_addr;
    ip = sin_ptr->sin_addr;
 
    if (ioctl(hsocket, SIOCGIFNETMASK, &ifr) < 0)
    {
//        perror("ioctl SIOCGIFNETMASK error");
        errorcount++;
    }
    sin_ptr = (struct sockaddr_in *)&ifr.ifr_addr;
    netmask = sin_ptr->sin_addr;

    if (ioctl(hsocket, SIOCGIFDSTADDR, &ifr) < 0)
    {
//        perror("ioctl SIOCGIFDSTADDR error");
        errorcount++;
    }
    sin_ptr = (struct sockaddr_in *)&ifr.ifr_addr;
    ptp = sin_ptr->sin_addr;
    memset(&mac,0,6);
 
    if(errorcount)
    {
        close(hsocket);
        if(!noticed)
            printf("couldn't get ppp0 interface!\nplease check your connection!\n\n");
        noticed++;
        sleep(3);
        goto init;
    }
    else
        noticed = 0;

    printf("ppp0 interface:\n");
    printf(" IP:      %s\n", inet_ntoa(ip));
    printf(" NetMask: %s\n", inet_ntoa(netmask));
    printf(" Server:  %s\n\n", inet_ntoa(ptp));

    sin.sin_addr = ip;
    sin.sin_port = htons(61440);
    sin.sin_family = AF_INET;
    if ((bind(hsocket,sa,sizeof(sin))) < 0)
    {
        printf( "can't bind udp port 61440!\n");
        return 0;
    }

    sin.sin_addr = ptp;
    printf("Activating connection...\n");

    workwell = 0;
keepalive:
    errorcount = 0;
    while(1)
    {
        sendlen = sendto(hsocket,&c1,8,MSG_NOSIGNAL,sa,sizeof(sin));
        if(sendlen < 0 || errorcount >= 5)
        {
            printf("socket error! reinit...\n");
            close(hsocket);
            goto init;
        }
        if(waitdata(hsocket,1000*1000))
        {
            fromlen = sizeof(sin);
            recvlen = recvfrom(hsocket,&c2,sizeof(c2),0,sa,&fromlen);
            ip = sin.sin_addr;
            break;
        }
        else
        {
            errorcount++;
            printf("recv2 timed out\n");
        }
    }
   
    memset(&c3,0,96);
    c3.sign = 7;
    c3.len = 96;
    c3.id = 3;
    c3.code1 = c2.code1;
    c3.unk1 = 0x2000200;
    c3.code0 = c2.code0;
    c3.check = 0x1312fc7;
    c3.unk2 = 0x7e;
    memcpy(&c3.mac,&mac,6);
    c3.devtype = 0x17;
    memcpy(&c3.ipaddr,&ip,4);
    memcpy(&c3.netmask,&netmask,4);
   
    ptr_long = (u_long *)&c3;
    for(n=0,check=0;n<96/4;n++)
        check ^= *(ptr_long + n);
    c3.check = check * 0x12C4B7E;
    c3.unk2 = 0;
   
    ptr = (u_char *)&c3.mac;
    for(n=0;n<64;n++)
        *(ptr + n) = (*(ptr + n) >> 8 - (n & 7)) + (*(ptr + n) << (n & 7));
   
    sendlen = sendto(hsocket,&c3,96,MSG_NOSIGNAL,sa,sizeof(sin));
    if(sendlen < 0 || errorcount >= 5)
    {
        printf("socket error! reinit...\n");
        close(hsocket);
        goto init;
    }
    if(waitdata(hsocket,1000*1000))
    {
        fromlen = sizeof(sin);
        recvlen = recvfrom(hsocket,&c2,sizeof(c2),0,sa,&fromlen);
        if(!workwell)
        {
        printf("Keeping connection active...\n");
        workwell++;
        }
    }
    else
    {
        printf("recv4 timed out\n");
        sleep(1);
        goto keepalive;
    }