mystar.c

linux / UNIX 802.1x协议下的开源代码

/*
   Mystar is an 802.1x client tool for Linux, which is compatible with MentoSupplicant3.8 for Windows.
   This file contains the main() function of mystar.
*/


#include "mystar.h"
#include "global.h"
#include "sendpacket.h"
#include "myerr.h"
#include "blog.h"
#include "conn_monitor.h"

/*   Note that: in this file, the global variables (defined without a leading "static")
  from here to the beginning of the definition of main() are referenced by sendpacket.c ( we
  reference them in the form of "extern ..." in sendpacket.c) */

/* These info should be retrieved from mystar.conf */
char         *m_name=NULL;//用户名
char         *m_password=NULL;//密码
int           m_authenticationMode=-1; //是哪种认证模式：0:标准 1:实达
static char  *m_nic=NULL;//网卡
static int    m_echoInterval= -1; //echo间隔, set to 0 to disable echo
static int    m_intelligentReconnect=-1; // 0:don't use it, 1: ues it.  NOTE: not supported NOW!!
static char  *m_fakeAddress=NULL;  // or set to "123.45.67.89" etc.
/* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
static char  *m_intelligentHost=NULL;
static unsigned int m_DbgInfoLevel = 0;
/* +++++++++++++++++++++++++++++++++++++++++++++++ By 夕霞孤雁 05.10.20    */

/* These information should be worked out by initialization portion. */
unsigned char         m_localMAC[6];//本机的MAC地址
unsigned char         m_destMAC[6];//服务器的MAC地址.
static unsigned char  m_ip[4];	//当前选择的网卡的IP地址
static unsigned char  m_netmask[4];//当前选择的网卡的子网掩码
static unsigned char  m_netgate[4];//当前选择的网卡的网关
static unsigned char  m_dns1[4];   //当前选择的网卡的DNS

/* 当前认证状态
   0:未找到服务器                      1:已找到服务器，未通过用户名认证
   2:已通过用户名认证，未通过MD5认证   3:已通过MD5认证，通网成功         */
static volatile sig_atomic_t m_state=0;//当前认证状态

ULONG_BYTEARRAY  m_serialNo;  //序列号,收到第一个有效的Authentication-Success-packet时初始化
ULONG_BYTEARRAY  m_key;       //密码加密键值,在main()函数开始时初始化

/////////////////////////////////////////////////////////////////////////
static void sig_intr(int signo); //do some cleanup work on exit with Ctrl+C
static void checkAndSetConfig(void); //configure related parameters


int main(int argc, char* argv[])
{
    libnet_t *                l=NULL;
    u_int32_t                 l_ip;
    char                      l_errbuf[LIBNET_ERRBUF_SIZE];
    struct libnet_ether_addr *l_ether_addr;

    pcap_t             *p=NULL;
    int                 p_fd;
    fd_set              read_set;
    char                filter_buf[256];
    struct bpf_program  filter_code;
    u_int32_t           p_netaddr,p_netmask;
    struct pcap_pkthdr *pkt_hdr;
    const u_char       *pkt_data;
    char                p_errbuf[PCAP_ERRBUF_SIZE];

    u_int16_t       offset;
    int             msgLen;
    char            msgBuf[256];
    char           *pmsgBuf;
    ULONG_BYTEARRAY uTemp;
    int             isFirstPacketFromServer=1;
    sigset_t        sigset_full,sigset_zero;
    struct timespec timeout;
    int packetCount_SentFindServer=0;
    int packetCount_SentName=0;
    int packetCount_SentPassword=0;


    m_serialNo.ulValue = 0x1000002a;        //the initial serial number, a magic number! Used to generate the Magic Numbers
    checkAndSetConfig(); //Set the arguments

    if((l=libnet_init(LIBNET_LINK, m_nic,l_errbuf))==NULL)
        err_quit("libnet_init: %s\n", l_errbuf);

    if((p=pcap_open_live(m_nic,65536,0, 500, p_errbuf))==NULL) //Get the libpcap handle
    { err_msg("pcap_open_live: %s\n",p_errbuf); goto err1; }
    p_fd=pcap_fileno(p); //we can pselect() it in the following code.
    //Get the Libpcap File Descriptor,Used by pselect() function

    //Get the Local Mac Address
    if((l_ether_addr=libnet_get_hwaddr(l))==NULL)
    { err_msg("unable to get local mac address :%s\n",libnet_geterror(l)); goto err2; };
    memcpy(m_localMAC,l_ether_addr,sizeof(m_localMAC));

    //Get the ip address
    if(m_fakeAddress==NULL)
    {
        if((l_ip=libnet_get_ipaddr4(l))==-1)
        { err_msg("unable to get ip address--ingored... :%s\n",libnet_geterror(l)); l_ip=0; }
        memcpy(m_ip,&l_ip,sizeof(m_ip));
    }
    else {}; //in this case , m_ip has been initialized in checkandSetConfig()

    //Get the netmask
    if(pcap_lookupnet(m_nic,&p_netaddr,&p_netmask,p_errbuf)==-1)
    { err_msg("unable to get netmask--igored... %s\n",p_errbuf); p_netmask=0;}
    memcpy(m_netmask,&p_netmask,sizeof(m_netmask));

    InitializeBlog(m_ip,m_netmask,m_netgate,m_dns1); //see blog.c and bloc.h for details

    //set the filter. Here I'm sure filter_buf is big enough.
    snprintf(filter_buf,sizeof(filter_buf),FILTER_STR, m_localMAC[0],m_localMAC[1],
             m_localMAC[2],m_localMAC[3],m_localMAC[4],m_localMAC[5]);
    // m_localMAC[2],m_localMAC[3],m_localMAC[4],m_localMAC[5],m_localMAC[6]);
    if(pcap_compile(p, &filter_code,filter_buf, 0, p_netmask)==-1)
    { err_msg("pcap_compile(): %s", pcap_geterr(p));  goto err2; }
    if(pcap_setfilter(p, &filter_code)==-1)
    { err_msg("pcap_setfilter(): %s", pcap_geterr(p)); goto err2; }
    pcap_freecode(&filter_code); // avoid  memory-leak

    (void)signal(SIGINT,sig_intr);  //We can exit with Ctrl+C
    (void)sigfillset(&sigset_full);
    (void)sigprocmask(SIG_BLOCK,&sigset_full,NULL); //block all signals.

    //search for the server
beginAuthentication:
    m_state=0;
    (void)SendFindServerPacket(l); //the first time to search for server
    packetCount_SentFindServer=1;
    packetCount_SentName=0;
    packetCount_SentPassword=0;

    while(1)
    {
        (void)sigfillset(&sigset_full);
        (void)sigdelset(&sigset_full,SIGINT);
        FD_ZERO(&read_set);  FD_SET(p_fd, &read_set);
        timeout.tv_sec =1;   timeout.tv_nsec =0; // 1 second

        //wait with all signals(except SIGINT) blocked.
        switch ( pselect(p_fd+1,&read_set,NULL,NULL,&timeout,&sigset_full) )
        {
        case -1: //Normally, this case should not happen since sig_intr() never returns!
            goto err2;
        case 0:  //timed out
            switch(m_state)
            {
            case 0:
                if(++packetCount_SentFindServer>3)
                { puts("Restarting authenticaton!"); goto beginAuthentication; }
                (void)SendFindServerPacket(l);
                continue; //jump to next loop of while(1) to receive next packet
            case 1:
                if(++packetCount_SentName>3)
                { puts("Restarting authenticaton!"); goto beginAuthentication; }
                (void)SendNamePacket(l, pkt_data);
                continue;
            case 2:
                if(++packetCount_SentPassword>3)
                { puts("Restarting authenticaton!"); goto beginAuthentication; }
                (void)SendPasswordPacket(l, pkt_data);
                continue;
            default:
                goto err2;
            }
        }

        //Here return value of pselect must be 1

        if((pcap_next_ex(p,&pkt_hdr,&pkt_data))!=1) continue;

        //收到的第二个及其以后的有效packet的源MAC必须等于头次收到的有效分组的源MAC
        if ((!isFirstPacketFromServer)&&(memcmp(m_destMAC,pkt_data+6,6)!=0)) continue;

        //received a packet successfully. for convenience, SUPPOSE it's the RIGHT packet!! but maybe WRONG!!
        //for example, we have NEVER vefified the length of packet, fancying the packet's length is 0x11 ?!

        switch( pkt_data[0x12] )        //分析EAP包类型
        {
        case 0x01:        //表示请求
            switch( pkt_data[0x16] )
            {
            case 0x01:   //type 1,以用户名应答
                if(m_state!=0) continue;
                m_state=1;
                fputs("@@ Server found, requesting user name...\n",stdout);
                if (isFirstPacketFromServer) //获得服务器的MAC地址
                { memcpy( m_destMAC, pkt_data+6, 6); isFirstPacketFromServer=0;}
                ++packetCount_SentName;
                (void)SendNamePacket(l, pkt_data);
                break;
            case 0x04:   //type 4,挑战，以MD5计算得到的值应答
                if(m_state!=1) continue;
                m_state=2;
                fputs("@@ User name valid, requesting password...\n",stdout);
                ++packetCount_SentPassword;
                (void)SendPasswordPacket(l, pkt_data);
                break;