#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <errno.h>
/* 接收緩沖區大小 */
#define RCV_BUF_SIZE 1024 * 5
/* 接收緩沖區 */
static int g_iRecvBufSize = RCV_BUF_SIZE;
static char g_acRecvBuf[RCV_BUF_SIZE] = {0};
/* 物理網卡接口,需要根據具體情況修改 */
static const char *g_szIfName = "eth1";
/* 以太網幀封裝的協議類型 */
static const int g_iEthProId[] = { ETHERTYPE_PUP,
ETHERTYPE_SPRITE,
ETHERTYPE_IP,
ETHERTYPE_ARP,
ETHERTYPE_REVARP,
ETHERTYPE_AT,
ETHERTYPE_AARP,
ETHERTYPE_VLAN,
ETHERTYPE_IPX,
ETHERTYPE_IPV6,
ETHERTYPE_LOOPBACK
};
static const char g_szProName[][24] = {
"none", "xerox pup", "sprite", "ip", "arp",
"rarp", "apple-protocol", "apple-arp",
"802.1q", "ipx", "ipv6", "loopback"
};
/* 輸出MAC地址 */
static void ethdump_showMac(const int iType, const char acHWAddr[])
{ int i = 0;
if (0 == iType)
{
printf("SMAC=[");
}
else
{
printf("DMAC=[");
}
for(i = 0; i < ETHER_ADDR_LEN - 1; i++)
{
printf("%02x:", *((unsigned char *)&(acHWAddr[i])));
}
printf("%02x] ", *((unsigned char *)&(acHWAddr[i])));
}
/* 物理網卡混雜模式屬性操作 */
static int ethdump_setPromisc(const char *pcIfName, int fd, int iFlags)
{ int iRet = -1;
struct ifreq stIfr;
/* 獲取接口屬性標誌位 */
strcpy(stIfr.ifr_name, pcIfName);
iRet = ioctl(fd, SIOCGIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Get Interface Flags");
return -1;
}
if (0 == iFlags)
{ /* 取消混雜模式 */
stIfr.ifr_flags &= ~IFF_PROMISC;
}
else
{ /* 設置為混雜模式 */
stIfr.ifr_flags |= IFF_PROMISC;
}
iRet = ioctl(fd, SIOCSIFFLAGS, &stIfr);
if (0 > iRet)
{ perror("[Error]Set Interface Flags");
return -1;
}
return 0;
}
/* 獲取L2幀封裝的協議類型 */
static char *ethdump_getProName(const int iProNum)
{ int iIndex = 0;
for(iIndex = 0; iIndex < sizeof(g_iEthProId) / sizeof(g_iEthProId[0]); iIndex++)
{ if (iProNum == g_iEthProId[iIndex])
{
break;
}
}
return (char *)(g_szProName[iIndex + 1]);
}
/* Init L2 Socket */
static int ethdump_initSocket()
{ int iRet = -1;
int fd = -1;
struct ifreq stIf;
struct sockaddr_ll stLocal = {0};
/* 創建SOCKET */
fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (0 > fd)
{ perror("[Error]Initinate L2 raw socket");
return -1;
}
/* 網卡混雜模式設置 */
ethdump_setPromisc(g_szIfName, fd, 1);
/* 設置SOCKET選項 */
iRet = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &g_iRecvBufSize,sizeof(int));
if (0 > iRet)
{ perror("[Error]Set socket option");
close(fd);
return -1;
}
/* 獲取物理網卡接口索引 */
strcpy(stIf.ifr_name, g_szIfName);
iRet = ioctl(fd, SIOCGIFINDEX, &stIf);
if (0 > iRet)
{ perror("[Error]Ioctl operation");
close(fd);
return -1;
}
/* 綁定物理網卡 */
stLocal.sll_family = PF_PACKET;
stLocal.sll_ifindex = stIf.ifr_ifindex;
stLocal.sll_protocol = htons(ETH_P_ALL);
iRet = bind(fd, (struct sockaddr *)&stLocal, sizeof(stLocal));
if (0 > iRet)
{ perror("[Error]Bind the interface");
close(fd);
return -1;
}
return fd;
}
/* 解析Ethernet幀首部 */
static int ethdump_parseEthHead(const struct ether_header *pstEthHead)
{ unsigned short usEthPktType;
if (NULL == pstEthHead)
{ return -1;}
/* 協議類型、源MAC、目的MAC */
usEthPktType = ntohs(pstEthHead->ether_type);
printf(">>>\nEth-Pkt-Type:0x%04x(%s) ", usEthPktType, ethdump_getProName(usEthPktType));
ethdump_showMac(0, pstEthHead->ether_shost);
ethdump_showMac(1, pstEthHead->ether_dhost);
return 0;
}
/* 解析IP數據包頭 */
static int ethdump_parseIpHead(const struct ip *pstIpHead)
{ struct protoent *pstIpProto = NULL;
if (NULL == pstIpHead)
{ return -1;}
/* 協議類型、源IP地址、目的IP地址 */
pstIpProto = getprotobynumber(pstIpHead->ip_p);
if(NULL != pstIpProto)
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, pstIpProto->p_name); }
else
{ printf("\nIP-Pkt-Type:%d(%s) ", pstIpHead->ip_p, "None");}
printf("SAddr=[%s] ", inet_ntoa(pstIpHead->ip_src));
printf("DAddr=[%s]\n", inet_ntoa(pstIpHead->ip_dst));
return 0;
}
/* 數據幀解析函數 */
static int ethdump_parseFrame(const char *pcFrameData)
{ int iRet = -1;
struct ether_header *pstEthHead = NULL;
struct ip *pstIpHead = NULL;
/* Ethnet幀頭解析 */
pstEthHead = (struct ether_header*)g_acRecvBuf;
iRet = ethdump_parseEthHead(pstEthHead);
if (0 > iRet)
{ return iRet;}
/* IP數據包類型 */
pstIpHead = (struct ip *)(pstEthHead + 1);
iRet = ethdump_parseIpHead(pstIpHead);
return iRet;
}
/* 捕獲網卡數據幀 */
static void ethdump_startCapture(const int fd)
{ int iRet = -1;
socklen_t stFromLen = 0;
/* 循環監聽 */
while(1)
{ /* 清空接收緩沖區 */
memset(g_acRecvBuf, 0, RCV_BUF_SIZE);
/* 接收數據幀 */
iRet = recvfrom(fd, g_acRecvBuf, g_iRecvBufSize, 0, NULL, &stFromLen);
if (0 > iRet)
{ continue;}
/* 解析數據幀 */
ethdump_parseFrame(g_acRecvBuf);
}
}
/* Main */
int main(int argc, char *argv[])
{ int iRet = -1;
int fd = -1;
/* 初始化SOCKET */
fd = ethdump_initSocket();
if(0 > fd) {
return -1;
}
/* 捕獲數據包 */
ethdump_startCapture(fd);
/* 關閉SOCKET */
close(fd);
return 0;
}
編譯命令
gcc -o a a.c
./a
實現效果圖
...
>>>Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:24:7e:dc:99:18] DMAC=[00:1a:92:ef:b6:dd] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.100] DAddr=[192.168.0.111]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:1(icmp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
>>> Eth-Pkt-Type:0x0800(ip) SMAC=[00:1a:92:ef:b6:dd] DMAC=[00:24:7e:dc:99:18] IP-Pkt-Type:6(tcp) SAddr=[192.168.0.111] DAddr=[192.168.0.100]
...