問題描述

我正在用混雜模式編寫一個(gè)帶有原始套接字的程序，我需要原始套接字而不是嗅探我發(fā)送的數(shù)據(jù)包.我只需要通過以太網(wǎng) rx 線(而不是 tx 線)讀取數(shù)據(jù).可能嗎?

I am writing a program with a Raw Socket in promiscuous mode and I need the raw socket not sniff the packet I send. I need to read only the data over the ethernet rx wire (not the tx wire). It's posible?

非常感謝.

推薦答案

解決方案是查看讀取的數(shù)據(jù)包是否為 PACKET_OUTGOING.使用此選項(xiàng)，您可以區(qū)分放入以太網(wǎng) tx 線的數(shù)據(jù)包和從 rx 線讀取的數(shù)據(jù)包.

The solution is to look in the read packet if it is a PACKET_OUTGOING. Using this option you can diference the packet you put in the ethernet tx wire and the packet you read from the rx wire.

以混雜模式打開套接字:

Open the Socket in promiscuous mode:

char* i = "eth0";
int fd;
struct ifreq ifr;
struct sockaddr_ll interfaceAddr;
struct packet_mreq mreq;

if ((fd = socket(PF_PACKET,SOCK_RAW,htons(ETH_P_ALL))) < 0)
    return -1;

memset(&interfaceAddr,0,sizeof(interfaceAddr));
memset(&ifr,0,sizeof(ifr));
memset(&mreq,0,sizeof(mreq));

memcpy(&ifr.ifr_name,i,IFNAMSIZ);
ioctl(fd,SIOCGIFINDEX,&ifr);

interfaceAddr.sll_ifindex = ifr.ifr_ifindex;
interfaceAddr.sll_family = AF_PACKET;

if (bind(fd, (struct sockaddr *)&interfaceAddr,sizeof(interfaceAddr)) < 0)
    return -2;


mreq.mr_ifindex = ifr.ifr_ifindex;
mreq.mr_type = PACKET_MR_PROMISC;
mreq.mr_alen = 6;

if (setsockopt(fd,SOL_PACKET,PACKET_ADD_MEMBERSHIP,
     (void*)&mreq,(socklen_t)sizeof(mreq)) < 0)
        return -3;
//...

并閱讀.現(xiàn)在，我們可以區(qū)分 Rx 和 Tx 以太網(wǎng)線:

And read. Now, We can differentiate between the Rx and Tx ethernet wire:

unsigned char buf[1500];
struct sockaddr_ll addr;
socklen_t addr_len = sizeof(addr);
n = recvfrom(fd, buf, 2000, 0, (struct sockaddr*)&addr, &addr_len);
if (n <= 0)
{
    //Error reading
}
else if (addr.sll_pkttype == PACKET_OUTGOING)
{
    //The read data are not writing by me.
    //Use only this data to copy in the other network.
}

這就是全部.使用它我不會(huì)讀取我寫的數(shù)據(jù).當(dāng)我將網(wǎng)絡(luò) 1 幀復(fù)制到網(wǎng)絡(luò) 2 并將網(wǎng)絡(luò) 2 幀復(fù)制到網(wǎng)絡(luò) 1 時(shí)，我避免了循環(huán).

And it's all. Using it I don't read the data I write. I avoid the loop when I copy the network 1 frames to network 2 and the network 2 frames to network 1.

這篇關(guān)于原始套接字混雜模式不嗅探我寫的內(nèi)容的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！