tango-tfe/plugin/business/traffic-mirror/src/ethdev.cpp

#include <unistd.h>
#include <pcap/pcap.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <assert.h>

#include <tfe_utils.h>
#include <tfe_proxy.h>
#include <traffic_mirror.h>

struct traffic_mirror_ethdev_pkt_desc{};
struct traffic_mirror_ethdev_pkt_desc_pcap
{
    unsigned int pktlen;
    char * pkt;
};

static int pcap_ethdev_inject(struct traffic_mirror_ethdev * ethdev, const char * pkt, unsigned int pktlen)
{
    return pcap_sendpacket(ethdev->pcap_device_handle, (const u_char *)pkt, pktlen);
}

static void pcap_ethdev_destroy(struct traffic_mirror_ethdev * ethdev)
{
    pcap_close(ethdev->pcap_device_handle);
    return free(ethdev);
}

void traffic_mirror_ethdev_destroy(struct traffic_mirror_ethdev * ethdev)
{
    ethdev->fn_destroy(ethdev);
}

int traffic_mirror_ethdev_inject(struct traffic_mirror_ethdev * ethdev, const char * pkt, unsigned int pktlen)
{
    return ethdev->fn_inject(ethdev, pkt, pktlen);
}

struct traffic_mirror_ethdev * traffic_mirror_ethdev_pcap_create(const char * str_ethdev, void * logger)
{
    struct traffic_mirror_ethdev * ethdev = ALLOC(struct traffic_mirror_ethdev, 1);
    char pcap_errbuf[PCAP_ERRBUF_SIZE] = {};

    int fd = 0;
    struct ifreq if_req{};

    ethdev->en_offload_ip_cksum = 0;
    ethdev->en_offload_tcp_cksum = 0;
    ethdev->en_offload_vlan = 0;

    /* open the device by pcap */
    ethdev->pcap_device_handle = pcap_open_live(str_ethdev, 0, 0, 0, pcap_errbuf);
    if (!ethdev->pcap_device_handle)
    {
        TFE_LOG_ERROR(logger, "failed at pcap_open_live(), device = %s: %s", str_ethdev, pcap_errbuf);
        goto errout;
    }

    /* local ether address */
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if(fd < 0)
    {
        TFE_LOG_ERROR(logger, "failed at create socket: %s", strerror(errno));
        goto errout;
    }

    memset(&if_req, 0, sizeof(if_req));
    strncpy(if_req.ifr_ifrn.ifrn_name, str_ethdev, IFNAMSIZ - 1);

    if(ioctl(fd, SIOCGIFHWADDR, &if_req) < 0)
    {
        TFE_LOG_ERROR(logger, "failed at read hwaddr of device %s: %s", str_ethdev, strerror(errno));
        goto errout;
    }

    for(int i = 0; i < 6; i++)
    {
        ethdev->local_ether_addr[i] = if_req.ifr_ifru.ifru_hwaddr.sa_data[i];
    }

    /* MTU */
    memset(&if_req, 0, sizeof(if_req));
    strncpy(if_req.ifr_ifrn.ifrn_name, str_ethdev, IFNAMSIZ - 1);

    if (ioctl(fd, SIOCGIFMTU, &if_req) < 0)
    {
        TFE_LOG_ERROR(logger, "failed at read mtu of device %s: %s", str_ethdev, strerror(errno));
        goto errout;
    }

    ethdev->mtu = if_req.ifr_ifru.ifru_mtu;
    strncpy(ethdev->str_device, str_ethdev, sizeof(ethdev->str_device) - 1);

    TFE_LOG_INFO(logger, "traffic mirror device %s (pcap mode): %02X:%02X:%02X:%02X:%02X:%02X, mtu=%u",
        ethdev->str_device, ethdev->local_ether_addr[0], ethdev->local_ether_addr[1],
        ethdev->local_ether_addr[2], ethdev->local_ether_addr[3],
        ethdev->local_ether_addr[4], ethdev->local_ether_addr[5], ethdev->mtu);

    ethdev->fn_inject = pcap_ethdev_inject;
    ethdev->fn_destroy = pcap_ethdev_destroy;

    close(fd);
    return ethdev;

errout:
    if (fd > 0) close(fd);
    if (ethdev->pcap_device_handle) pcap_close(ethdev->pcap_device_handle);
    if (ethdev) FREE(&ethdev);
    return nullptr;
}