这些东西可以通过socket上的ioctl()系统调用获得，附件里是我用strace工具追踪PC上的ifconfig eth0的输出，注意看其中ioctl的部分：
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 4
..
socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP) = 5
...
ioctl(5, SIOCGIFFLAGS, {ifr_name="eth0", ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(5, SIOCGIFHWADDR, {ifr_name="eth0", ifr_hwaddr=00:1c:c4:1f:01:99}) = 0
ioctl(5, SIOCGIFMETRIC, {ifr_name="eth0", ifr_metric=0}) = 0
ioctl(5, SIOCGIFMTU, {ifr_name="eth0", ifr_mtu=1500}) = 0
ioctl(5, SIOCGIFMAP, {ifr_name="eth0", ifr_map={mem_start=0, mem_end=0, base_addr=0, irq=17, dma=0, port=0}}) = 0
ioctl(5, SIOCGIFMAP, {ifr_name="eth0", ifr_map={mem_start=0, mem_end=0, base_addr=0, irq=17, dma=0, port=0}}) = 0
ioctl(5, SIOCGIFTXQLEN, {ifr_name="eth0", ifr_qlen=1000}) = 0
...
ioctl(4, SIOCGIFADDR, {ifr_name="eth0", ifr_addr={AF_INET, inet_addr("16.157.12.196")}}) = 0
ioctl(4, SIOCGIFDSTADDR, {ifr_name="eth0", ifr_dstaddr={AF_INET, inet_addr("16.157.12.196")}}) = 0
ioctl(4, SIOCGIFBRDADDR, {ifr_name="eth0", ifr_broadaddr={AF_INET, inet_addr("16.157.15.255")}}) = 0
ioctl(4, SIOCGIFNETMASK, {ifr_name="eth0", ifr_netmask={AF_INET, inet_addr("255.255.248.0")}}) = 0
