Question

我需要获取有关FreeBSD主机（位于VirtualBox上）上所有已连接网络接口的信息。我使用了StackOverflow上的代码段。在Linux上，它运行良好，但是在FreeBSD上，发生了一些奇怪的事情。这是我使用的代码：

#include <unistd.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <stdio.h>
#include <arpa/inet.h>

int main(void)
{
    char          buf[8096];
    struct ifconf ifc;
    struct ifreq *ifr;
    int           sck;
    int           nInterfaces;
    int           i;

    /* Get a socket handle. */
    sck = socket(AF_INET, SOCK_DGRAM, 0);
    if(sck < 0)
    {
        perror("socket");
        return 1;
    }

    /* Query available interfaces. */
    ifc.ifc_len = sizeof(buf);
    ifc.ifc_buf = buf;
    if(ioctl(sck, SIOCGIFCONF, &ifc) < 0)
    {
        perror("ioctl(SIOCGIFCONF)");
        return 1;
    }

    /* Iterate through the list of interfaces. */
    ifr         = ifc.ifc_req;
    write(2, ifr, ifc.ifc_len);

    nInterfaces = ifc.ifc_len / sizeof(struct ifreq);
    printf("%d\n", nInterfaces);
    for(i = 0; i < nInterfaces; i++)
    {
        struct ifreq *item = &ifr[i];

    /* Show the device name and IP address */
        printf("%s: IP %s", item->ifr_name,inet_ntoa(((struct sockaddr_in *)&item->ifr_addr)->sin_addr));


    /* Get the broadcast address (added by Eric) */
        if(ioctl(sck, SIOCGIFBRDADDR, item) >= 0)
            printf(", BROADCAST %s", inet_ntoa(((struct sockaddr_in *)&item->ifr_broadaddr)->sin_addr));
        printf("\n");
    }

        return 0;
}

Linux上的输出是：

3
lo: IP 127.0.0.1, BROADCAST 0.0.0.0
wlxf4f26d1cdfaf: IP 192.168.1.123, BROADCAST 192.168.1.255
vboxnet0: IP 192.168.56.1, BROADCAST 192.168.56.255

在FreeBSD上，输出为：

9
em0: IP 6.3.6.0, BROADCAST 192.168.56.255
�: IP 0.0.0.0
: IP 0.0.0.0
: IP 0.0.0.0
lo0: IP 0.0.0.0
: IP 0.0.0.0
: IP 0.0.0.1
: IP 254.128.0.2
: IP 0.0.0.0

以下是FreeBSD上ifconfig的输出：

em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=81009b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,VLAN_HWFILTER>
        ether 08:00:27:5f:63:c7
        inet 192.168.56.101 netmask 0xffffff00 broadcast 192.168.56.255 
        media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
        options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
        inet6 ::1 prefixlen 128 
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2 
        inet 127.0.0.1 netmask 0xff000000 
        groups: lo 
        nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

在FreeBSD上获取网络接口信息

0 个答案: