net.c

在LINUX下获取AP/BRIDGE的IP OR MAC

#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <assert.h>
#include <pthread.h>
#include <stdio.h>
#include <errno.h>  
#include <unistd.h>
#include <fcntl.h>

#include <sys/socket.h>
#include <sys/types.h>  
#include <sys/ioctl.h> 
#include <sys/time.h>

#include <linux/in.h>
//#include <arpa/inet.h>
#include <linux/if_arp.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/filter.h>

/*获取主机ＩＰ、ＭＡＣ地址以及子网掩码*/
int GetHostAddr(unsigned char * pMac, unsigned char * pIP, unsigned char * pMask)
{
	int s,nRes;
	unsigned char * p;
	unsigned long nl;
	struct ifreq ifr; 
	s=socket(PF_INET, SOCK_DGRAM,0 ); 
	if( s >= 0) 
	{
        bzero(&ifr, sizeof(ifr));
        strncpy(ifr.ifr_name, "eth0",16); 
		/*Get Host IP*/
		if(ioctl (s, SIOCGIFADDR, &ifr)>=0)
		{
			if(pIP)
			{
				nl = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
				memcpy((void*)pIP, (void*)&nl, 4);
				p = pIP;
				printf("Local Host:%02X%02X%02X%02X", p,p[1],p[2],p[3]);
			}
		}
		/*Get host netmask*/
		if(ioctl (s, SIOCGIFNETMASK, &ifr)>=0)
		{
			if(pMask)
			{
				nl = ((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr.s_addr;
				memcpy((void*)pMask, (void*)&nl, 4);
				p = pMask;
				printf("Local Host:%02X%02X%02X%02X", p,p[1],p[2],p[3]);
			}
		}
		nRes = ioctl(s, SIOCGIFHWADDR, &ifr);
		close(s);
		if ( nRes< 0)
			perror("ioctl() get hardware address error:");
		else 
		{
			p = (unsigned char*) &ifr.ifr_hwaddr.sa_data;
			if(pMac)
				memcpy(pMac, p, 6);
			return 6;
		}		
	}
	return -1;
}
int GetBridgeAddr(unsigned  char * pMac, unsigned char * pIP)
{
	int s,nRes,n, i,ifindex;
	unsigned char buffer[2048];
	unsigned char hostmac[12];
	unsigned char *iphead, *ethhead;
	unsigned long ip;
	struct ifreq ethreq;
	struct sockaddr_ll socket_address;
	
	n = -1;

	bzero(buffer, sizeof(buffer));
	s = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
	if (s != -1) 
	{
		strncpy(ethreq.ifr_name, "eth0", IFNAMSIZ);
		if (ioctl(s, SIOCGIFINDEX, &ethreq) != -1) 
		{
			ifindex = ethreq.ifr_ifindex;
			if (ioctl(s, SIOCGIFHWADDR, &ethreq) != -1) 
			{
				for (i = 0; i < 6; i++) 
					hostmac[i] = ethreq.ifr_hwaddr.sa_data[i];
				socket_address.sll_family   = PF_PACKET;
				socket_address.sll_protocol = htons(ETH_P_IP);
				socket_address.sll_ifindex  = ifindex;
				socket_address.sll_hatype   = ARPHRD_ETHER;
				socket_address.sll_pkttype  = PACKET_OTHERHOST;
				socket_address.sll_halen    = ETH_ALEN;
				socket_address.sll_addr[6]  = 0x00; 
				socket_address.sll_addr[7]  = 0x00;
				socket_address.sll_addr[0]  = 0x03;
				socket_address.sll_addr[1]  = 0x00;
				socket_address.sll_addr[2]  = 0x00;
				socket_address.sll_addr[3]  = 0x00;
				socket_address.sll_addr[4]  = 0x00;
				socket_address.sll_addr[5]  = 0x07;

				/*Send the discovery packet 4 times.*/
				buffer[0] = 0x03;
				buffer[1] = 0x00;
				buffer[2] = 0x00;
				buffer[3] = 0x00;
				buffer[4] = 0x00;
				buffer[5] = 0x07;
				
				buffer[12] = 0x38;
				buffer[13] = 0x42;
				memcpy(buffer+6, hostmac, 6);
				buffer[0x12] = 0x01;
				buffer[0x14] = 0x81;
				buffer[0x15] = 0x04;
				buffer[0x17] = 0x01;
				buffer[0x20] = 0x01;
				buffer[0x24] = 0x03;
				sendto(s, buffer, 70, 0, (struct sockaddr*)&socket_address, sizeof(socket_address));
				sendto(s, buffer, 70, 0, (struct sockaddr*)&socket_address, sizeof(socket_address));
				sendto(s, buffer, 70, 0, (struct sockaddr*)&socket_address, sizeof(socket_address));
				sendto(s, buffer, 70, 0, (struct sockaddr*)&socket_address, sizeof(socket_address));
				nRes = 0;
				while(nRes<1000)
				{
					n = recvfrom(s,buffer,2048,0,NULL,NULL);
					if (n>=42) 
					{
						if(memcmp(buffer,hostmac, 6)==0 && buffer[12] == 0x38 && buffer[13] == 0x42)
						{
							memcpy(pMac,buffer +6, 6);
							memcpy(&ip, buffer+0x4a,4);
							//sprintf(buffer, "Bridge IP:%08X", ip);
							pIP[0] = (ip&0xFF000000) >>24;
							pIP[1] = (ip&0x00FF0000) >>16;
							pIP[2] = (ip&0x0000FF00) >>8;
							pIP[3] =  ip&0x000000FF;
							n = 6;
							break;
						}
					}
					nRes ++;
				}
				if(nRes ==1000)
					n = -1;
			}
		}
	}
	close(s);
	return n;
}