ec_inet_linux.c

Ettercap最初设计为交换网上的sniffer

   static struct sockaddr_ll dest;
   static struct ifreq ifr;
#else
   static struct sockaddr dest;
#endif

   if (first_time)
   {
      memset(&dest, 0, sizeof (dest));
      first_time = 0;

      #if defined (HAVE_PF_PACKET) && defined (NETPACKET_PACKET_H)

         memset(&ifr, 0, sizeof(ifr));
         strncpy(ifr.ifr_name, Options.netiface, sizeof(ifr.ifr_name));

         if ( ioctl(sock, SIOCGIFINDEX, &ifr) < 0)
            ERROR_MSG("ioctl(SIOCGIFINDEX)");

         dest.sll_family = AF_PACKET;
         dest.sll_ifindex = ifr.ifr_ifindex;
         dest.sll_protocol = htons(ETH_P_ALL);
      #else
         strncpy(dest.sa_data, Options.netiface, sizeof (dest.sa_data));
      #endif
   }

   sent = sendto(sock, buffer, len, 0, (struct sockaddr *)&dest, sizeof(dest));
   if (sent < len)
   {
      while (errno == ENOBUFS)
      {
         usleep(5000);
         sent = sendto(sock, buffer, len, 0, (struct sockaddr *)&dest, sizeof(dest));
         if (sent == len) return (sent);
      }

      Error_msg("ec_inet_linux:%d sendto() %d(%d) | ERRNO : %d | %s \n", __LINE__, len, sent, errno, strerror(errno));
   }

   return (sent);

}



int Inet_SetPromisc(char *iface)
{

   int sock;
   struct ifreq ifr;

   DEBUG_MSG("Inet_SetPromisc\tiface: %s", iface);

   sock = Inet_OpenRawSock(iface);

   memset(&ifr, 0, sizeof(ifr));
   strncpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name));

   if ( ioctl(sock, SIOCGIFFLAGS, &ifr) < 0 )
      ERROR_MSG("ioctl(SIOCGIFFLAGS)");

   memset(&old_ifr, 0, sizeof(old_ifr));
   old_ifr.ifr_flags = ifr.ifr_flags;              //save old flags

   if (!(ifr.ifr_flags & IFF_PROMISC))
   {
      ifr.ifr_flags |= IFF_PROMISC;
      if ( ioctl(sock, SIOCSIFFLAGS, &ifr) < 0 )      // promisc mode
         ERROR_MSG("ioctl(SIOCSIFFLAGS) | promisc on");
      atexit(Inet_Restore_ifr);
   }


   Inet_CloseRawSock(sock);
   return 0;

}



void Inet_Restore_ifr(void)
{
   int sock;
   struct ifreq ifr;

   DEBUG_MSG("Inet_Restore_ifr");

   sock = Inet_OpenRawSock(Options.netiface);

   memset(&ifr, 0, sizeof(ifr));
   strncpy(ifr.ifr_name, Options.netiface, sizeof(ifr.ifr_name));

   ifr.ifr_flags = old_ifr.ifr_flags;

   if ( ioctl(sock, SIOCSIFFLAGS, &ifr) < 0 )     // flag restoring
      ERROR_MSG("ioctl(SIOCSIFFLAGS) | flag restoring");

   Inet_CloseRawSock(sock);
}


void Inet_DisableForwarding(void)
{
   FILE *fd;

   fd = fopen("/proc/sys/net/ipv4/ip_forward", "r");
   if (fd == NULL)
      Error_msg("failed to open /proc/sys/net/ipv4/ip_forward");

   fscanf(fd, "%c", &IpForward_status);
   fclose(fd);

   DEBUG_MSG("Inet_DisableForwarding from %c", IpForward_status);

   atexit(Inet_RestoreForwarding);

   fd = fopen("/proc/sys/net/ipv4/ip_forward", "w");
   if (fd == NULL)
      Error_msg("failed to open /proc/sys/net/ipv4/ip_forward");

   fprintf(fd, "0");
   fclose(fd);
}



void Inet_RestoreForwarding(void)
{
   FILE *fd;

   if (strcmp(ECThread_getname(pthread_self()), PROGRAM)) return;

   fd = fopen("/proc/sys/net/ipv4/ip_forward", "w");
   if (fd == NULL)
      Error_msg("failed to open /proc/sys/net/ipv4/ip_forward");

   DEBUG_MSG("Inet_RestoreForwarding to %c", IpForward_status);

   fprintf(fd, "%c", IpForward_status );
   fclose(fd);
}



char *Inet_MacFromIP(unsigned long ip)
{
   int sock_raw;
   static struct arpreq ar;
   struct sockaddr_in *sa_in;

   DEBUG_MSG("Inet_MacFromIP");

   memset((char *)&ar, 0, sizeof(ar));
   strncpy(ar.arp_dev, Options.netiface, sizeof(ar.arp_dev));
   sa_in = (struct sockaddr_in *)&ar.arp_pa;
   sa_in->sin_family = AF_INET;
   sa_in->sin_addr.s_addr = ip;

   sock_raw =Inet_OpenRawSock(Options.netiface);

   if (ioctl(sock_raw, SIOCGARP, (caddr_t)&ar) == -1)  // not in cache... try to find it...
   {
      struct recv_packet recvpck;
      char MyMAC[6];
      u_long MyIP;
      int MTU, sock;
      TIME_DECLARE;

      DEBUG_MSG("Inet_MacFromIP -- try to find it");

      sock = Inet_OpenRawSock(Options.netiface);

      Inet_GetIfaceInfo(Options.netiface, &MTU, MyMAC, &MyIP, NULL);

      if (ip == MyIP) {
         DEBUG_MSG("Inet_MacFromIP -- try to find me... ;)");

         memcpy(&ar.arp_ha.sa_data, MyMAC, ETHER_ADDR_LEN);
         Inet_CloseRawSock(sock);
         Inet_CloseRawSock(sock_raw);
         return (char *) ar.arp_ha.sa_data;
      }

      recvpck.buf = Inet_Forge_packet( MTU + ALIGN_ETH_TO_WORD );
      recvpck.aligned = recvpck.buf + ALIGN_ETH_TO_WORD;

      Inet_Forge_ethernet( recvpck.aligned, MyMAC, ETH_BROADCAST, ETH_P_ARP );

      Inet_Forge_arp(recvpck.aligned + ETH_HEADER, ARPOP_REQUEST,
                         MyMAC, MyIP,
                         ARP_BROADCAST, ip );

      Inet_SendRawPacket(sock, recvpck.aligned, ETH_HEADER + ARP_HEADER);

		memset(recvpck.aligned, 0, MTU);

      fcntl(sock, F_SETFL, O_NONBLOCK);
      TIME_START;

      do
      {
         int len;
         short pkttype;
         ETH_header *ethpkt;
         ARP_header *arppkt;

         len = Inet_GetRawPacket(sock, recvpck.aligned, MTU, &pkttype);

         ethpkt = (ETH_header *)recvpck.aligned;
         arppkt = (ARP_header *)(ethpkt + 1);

         TIME_FINISH;

         if (len > 0 && pkttype == PACKET_HOST && ethpkt->type == htons(ETH_P_ARP) && arppkt->opcode == htons(ARPOP_REPLY))
         {
            if ( *(unsigned long *)arppkt->source_ip == ip )
            {
               memcpy(&ar.arp_ha.sa_data, &arppkt->source_add, ETHER_ADDR_LEN);
               Inet_Forge_packet_destroy( recvpck.buf );
               Inet_CloseRawSock(sock);
               Inet_CloseRawSock(sock_raw);
               return (char *) ar.arp_ha.sa_data;
            }
         }
      } while ( TIME_ELAPSED < 0.5 );

		Inet_Forge_packet_destroy( recvpck.buf );
      Inet_CloseRawSock(sock);
      Inet_CloseRawSock(sock_raw);
      return ETH_BROADCAST;  // workaround for non local ip
   }

   Inet_CloseRawSock(sock_raw);
   return (char *) ar.arp_ha.sa_data;

}

#ifdef PERMIT_HTTPS

// ARP ENTRY MANAGEMENT ---------------------------

unsigned long SavedIP;
unsigned char SavedMAC[6];

void Inet_UnSetARPEntry(void)
{
   struct arpreq req;
   int sockfd;
   struct sockaddr_in *sa_in;

   DEBUG_MSG("Inet_UnSetARPEntry");

   sockfd = socket(AF_INET, SOCK_DGRAM, 0);

   memset((char *) &req, 0, sizeof(req));
   sa_in = (struct sockaddr_in *)&req.arp_pa;
   sa_in->sin_family = AF_INET;
   sa_in->sin_addr.s_addr = SavedIP;
   req.arp_flags = ATF_PERM | ATF_COM;

   memcpy(req.arp_ha.sa_data, SavedMAC, 6);
   strlcpy(req.arp_dev, Options.netiface, sizeof(req.arp_dev));

   ioctl(sockfd, SIOCDARP, &req);

   close(sockfd);
}


int Inet_SetARPEntry(unsigned long IP, char MAC[6])
{
   struct arpreq req;
   int sockfd;
   struct sockaddr_in *sa_in;
   int retval;

   DEBUG_MSG("Inet_SetARPEntry");

   sockfd = socket(AF_INET, SOCK_DGRAM, 0);

   memset((char *) &req, 0, sizeof(req));
   sa_in = (struct sockaddr_in *)&req.arp_pa;
   sa_in->sin_family = AF_INET;
   sa_in->sin_addr.s_addr = IP;
   req.arp_flags = ATF_PERM | ATF_COM;

   memcpy(req.arp_ha.sa_data, MAC, 6);
   strlcpy(req.arp_dev, Options.netiface, sizeof(req.arp_dev));

   retval = ioctl(sockfd, SIOCSARP, &req);

   close(sockfd);

   SavedIP=IP;
   memcpy(SavedMAC, MAC, 6);
   atexit(Inet_UnSetARPEntry);

   return retval;
}

// ROUTE MANAGEMENT ---------------------------

struct rtentry
{
    unsigned long int rt_pad1;
    struct sockaddr_in rt_dst;
    struct sockaddr_in rt_gateway;
    struct sockaddr_in rt_genmask;
    unsigned short int rt_flags;
    short int rt_pad2;
    unsigned long int rt_pad3;
    unsigned char rt_tos;
    unsigned char rt_class;
    short int rt_pad4;
    short int rt_metric;
    char *rt_dev;
    unsigned long int rt_mtu;
    unsigned long int rt_window;
    unsigned short int rt_irtt;
};

void Inet_UnsetRoute(void)
{
    int skfd;
    struct rtentry rt;

    DEBUG_MSG("Inet_UnsetRoute");

    skfd = socket(AF_INET, SOCK_DGRAM, 0);

    memset((char *)&rt,0, sizeof(struct rtentry));

    rt.rt_dst.sin_family=AF_INET;
    rt.rt_dst.sin_addr.s_addr=inet_addr("1.0.0.1");
    rt.rt_genmask.sin_family=AF_INET;
    rt.rt_genmask.sin_addr.s_addr=inet_addr("255.255.255.255");
    rt.rt_flags=5;
    rt.rt_dev=Options.netiface;

    ioctl(skfd, SIOCDELRT, &rt);

    rt.rt_dst.sin_addr.s_addr=inet_addr("1.0.0.0");
    rt.rt_gateway.sin_family=AF_INET;
    rt.rt_gateway.sin_addr.s_addr=inet_addr("1.0.0.1");
    rt.rt_genmask.sin_addr.s_addr=inet_addr("255.0.0.0");
    rt.rt_flags=3;

    ioctl(skfd, SIOCDELRT, &rt);

    close(skfd);
}

void Inet_SetRoute(void)
{
    int skfd;
    struct rtentry rt;

    DEBUG_MSG("Inet_SetRoute");

    skfd = socket(AF_INET, SOCK_DGRAM, 0);

    memset((char *)&rt,0, sizeof(struct rtentry));

    rt.rt_dst.sin_family=AF_INET;
    rt.rt_dst.sin_addr.s_addr=inet_addr("1.0.0.1");
    rt.rt_genmask.sin_family=AF_INET;
    rt.rt_genmask.sin_addr.s_addr=inet_addr("255.255.255.255");
    rt.rt_flags=5;
    rt.rt_dev=Options.netiface;

    ioctl(skfd, SIOCADDRT, &rt);

    rt.rt_dst.sin_addr.s_addr=inet_addr("1.0.0.0");
    rt.rt_gateway.sin_family=AF_INET;
    rt.rt_gateway.sin_addr.s_addr=inet_addr("1.0.0.1");
    rt.rt_genmask.sin_addr.s_addr=inet_addr("255.0.0.0");
    rt.rt_flags=3;

    ioctl(skfd, SIOCADDRT, &rt);

    close(skfd);

    atexit(Inet_UnsetRoute);
}

#endif

/* EOF */

// vim:ts=3:expandtab