netlink例子(1)

这个程序用来打印本机的网卡信息.也就是说直接和内核通信,然后获取所需要的数据.

 

#include <stdio.h> #include <string.h> #include <errno.h> #include <sys/socket.h> #include <sys/types.h> #include <unistd.h> #include <asm/types.h> #include <linux/netlink.h> #include <linux/rtnetlink.h> #include <linux/netdevice.h> #include <net/if_arp.h> #include <netinet/if_ether.h> #include <netinet/ether.h> int main() { int nSocket, nLen, nAttrLen; char szBuffer[4096]; struct { struct nlmsghdr nh; struct ifinfomsg ifi; }struReq; struct sockaddr_nl struAddr; struct nlmsghdr *pstruNL; struct ifinfomsg *pstruIF; struct rtattr *pstruAttr; struct net_device_stats *pstruInfo; struct ether_addr *pstruEther; /* * 创建一个PF_NETLINK的SOCKET,使用NETLINK_ROUTE协议 */ nSocket = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); if(nSocket < 0) { fprintf(stderr, "创建SOCKET错误:%s/n", strerror(errno)); return -1; } /* * 绑定地址 */ memset(&struAddr, 0, sizeof(struAddr)); struAddr.nl_family = AF_NETLINK; struAddr.nl_pid = getpid(); struAddr.nl_groups = 0; if(bind(nSocket, (struct sockaddr *)&struAddr, sizeof(struAddr)) < 0) { fprintf(stderr, "绑定SOCKET错误:%s/n", strerror(errno)); return -1; } /* * 发送一个请求 */ memset(&struReq, 0, sizeof(struReq)); struReq.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struReq)); struReq.nh.nlmsg_type = RTM_GETLINK; struReq.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; struReq.ifi.ifi_family = AF_UNSPEC; memset(&struAddr, 0, sizeof(struAddr)); struAddr.nl_family = AF_NETLINK; struAddr.nl_pid = 0; struAddr.nl_groups = 0; if(sendto(nSocket, &struReq, struReq.nh.nlmsg_len, 0, (struct sockaddr *)&struAddr, sizeof(struAddr)) < 0) { fprintf(stderr, "发送数据错误:%s/n", strerror(errno)); return -1; } /* * 循环接收数据，直到超时 */ alarm(30); memset(szBuffer, 0, sizeof(szBuffer)); while((nLen = recv(nSocket, szBuffer, sizeof(szBuffer), 0))) { alarm(0); pstruNL = (struct nlmsghdr *)szBuffer; /* * 判断是否继续有数据 */ while(NLMSG_OK(pstruNL, nLen)) { /* * 数据已经获取完成 */ if(pstruNL -> nlmsg_type == NLMSG_DONE) break; if(pstruNL -> nlmsg_type == NLMSG_ERROR) { /* * 发生一个错误 */ struct nlmsgerr *pstruError; pstruError = (struct nlmsgerr *)NLMSG_DATA(pstruNL); fprintf(stderr, "发生错误[%s]/n", strerror(-pstruError -> error)); break; } /* * 下面通过宏获取数据 */ pstruIF = NLMSG_DATA(pstruNL); fprintf(stderr, "获取到设备[%d]信息/n", pstruIF -> ifi_index); fprintf(stderr, "/t设备类型:"); switch(pstruIF -> ifi_type) { case ARPHRD_ETHER: fprintf(stderr, "以太网/n"); break; case ARPHRD_PPP: fprintf(stderr, "PPP拨号/n"); break; case ARPHRD_LOOPBACK: fprintf(stderr, "环路设备/n"); break; default: fprintf(stderr, "未知/n"); break; } fprintf(stderr, "/t设备状态:"); if((pstruIF -> ifi_flags & IFF_UP )== IFF_UP) fprintf(stderr, " UP"); if((pstruIF -> ifi_flags & IFF_BROADCAST) == IFF_BROADCAST) fprintf(stderr, " BROADCAST"); if((pstruIF -> ifi_flags & IFF_DEBUG) == IFF_DEBUG) fprintf(stderr, " DEBUG"); if((pstruIF -> ifi_flags & IFF_LOOPBACK) == IFF_LOOPBACK) fprintf(stderr, " LOOPBACK"); if((pstruIF -> ifi_flags & IFF_POINTOPOINT) == IFF_POINTOPOINT) fprintf(stderr, " POINTOPOINT"); if((pstruIF -> ifi_flags & IFF_RUNNING) == IFF_RUNNING) fprintf(stderr, " RUNNING"); if((pstruIF -> ifi_flags & IFF_NOARP) == IFF_NOARP) fprintf(stderr, " NOARP"); if((pstruIF -> ifi_flags & IFF_PROMISC) == IFF_PROMISC) fprintf(stderr, " PROMISC"); if((pstruIF -> ifi_flags & IFF_NOTRAILERS) == IFF_NOTRAILERS) fprintf(stderr, " NOTRAILERS"); if((pstruIF -> ifi_flags & IFF_ALLMULTI) == IFF_ALLMULTI) fprintf(stderr, " ALLMULTI"); if((pstruIF -> ifi_flags & IFF_MASTER) == IFF_MASTER) fprintf(stderr, " MASTER"); if((pstruIF -> ifi_flags & IFF_SLAVE) == IFF_SLAVE) fprintf(stderr, " SLAVE"); if((pstruIF -> ifi_flags & IFF_MULTICAST) == IFF_MULTICAST) fprintf(stderr, " MULTICAST"); if((pstruIF -> ifi_flags & IFF_PORTSEL) == IFF_PORTSEL) fprintf(stderr, " SLAVE"); if((pstruIF -> ifi_flags & IFF_AUTOMEDIA) == IFF_AUTOMEDIA) fprintf(stderr, " AUTOMEDIA"); if((pstruIF -> ifi_flags & IFF_DYNAMIC) == IFF_DYNAMIC) fprintf(stderr, " DYNAMIC"); fprintf(stderr, "/n"); /* * 下面通过宏获取属性 */ pstruAttr = IFLA_RTA(pstruIF); nAttrLen = NLMSG_PAYLOAD(pstruNL, sizeof(struct ifinfomsg)); while(RTA_OK(pstruAttr, nAttrLen)) { switch(pstruAttr->rta_type) { case IFLA_IFNAME: fprintf(stderr, "/t设备名称:%s/n", (char *)RTA_DATA(pstruAttr)); break; case IFLA_MTU: fprintf(stderr, "/t设备MTU:%d/n", *(unsigned int *)RTA_DATA(pstruAttr)); break; case IFLA_QDISC: fprintf(stderr, "/t设备队列:%s/n", (char *)RTA_DATA(pstruAttr)); break; case IFLA_ADDRESS: if(pstruIF -> ifi_type == ARPHRD_ETHER) { pstruEther = (struct ether_addr *) RTA_DATA(pstruAttr); fprintf(stderr, "/tMAC地址:%s/n", ether_ntoa(pstruEther)); } break; case IFLA_BROADCAST: if(pstruIF -> ifi_type == ARPHRD_ETHER) { pstruEther = (struct ether_addr *) RTA_DATA(pstruAttr); fprintf(stderr, "/t广播MAC地址:%s/n", ether_ntoa(pstruEther)); } break; case IFLA_STATS: pstruInfo = (struct net_device_stats *) RTA_DATA(pstruAttr); fprintf(stderr, "/t接收信息:/n"); fprintf(stderr, "/t/t接收报文:%lu 字节:%lu/n", pstruInfo -> rx_packets, pstruInfo -> rx_bytes); fprintf(stderr, "/t/terrors:%lu dropped:%lu " "multicast:%lu collisions:%lu/n", pstruInfo -> rx_errors, pstruInfo -> rx_dropped, pstruInfo -> multicast, pstruInfo -> collisions); fprintf(stderr, "/t/tlength:%lu over:%lu crc:%lu " "frame:%lu fifo:%lu missed:%lu/n", pstruInfo -> rx_length_errors, pstruInfo -> rx_over_errors, pstruInfo -> rx_crc_errors, pstruInfo -> rx_frame_errors, pstruInfo -> rx_fifo_errors, pstruInfo -> rx_missed_errors); fprintf(stderr, "/t发送信息:/n"); fprintf(stderr, "/t/t发送报文:%lu 字节:%lu/n", pstruInfo -> tx_packets, pstruInfo -> tx_bytes); fprintf(stderr, "/t/terrors:%lu dropped:%lu/n", pstruInfo -> tx_errors, pstruInfo -> tx_dropped); fprintf(stderr, "/t/taborted:%lu carrier:%lu fifo:%lu" " heartbeat:%lu window:%lu/n", pstruInfo -> tx_aborted_errors, pstruInfo -> tx_carrier_errors, pstruInfo -> tx_fifo_errors, pstruInfo -> tx_heartbeat_errors, pstruInfo -> tx_window_errors); break; default: break; } /* * 继续下一个属性 */ pstruAttr = RTA_NEXT(pstruAttr, nAttrLen); } /* * 继续下一个数据 */ pstruNL = NLMSG_NEXT(pstruNL, nLen); } memset(szBuffer, 0, sizeof(szBuffer)); alarm(30); } return 0; }

 

输出结果:

root@wangxiaoming:~/Desktop/root/aodv/nelink_test/test1# ./netlink_test 获取到设备[1]信息 设备类型:环路设备 设备状态: UP LOOPBACK RUNNING 设备名称:lo 设备MTU:16436 设备队列:noqueue 接收信息: 接收报文:212 字节:12720 errors:0 dropped:0 multicast:0 collisions:0 length:0 over:0 crc:0 frame:0 fifo:0 missed:0 发送信息: 发送报文:212 字节:12720 errors:0 dropped:0 aborted:0 carrier:0 fifo:0 heartbeat:0 window:0 获取到设备[2]信息 设备类型:以太网 设备状态: UP BROADCAST RUNNING MULTICAST 设备名称:eth0 设备MTU:1500 设备队列:pfifo_fast MAC地址:0:c:29:97:c2:4a 广播MAC地址:ff:ff:ff:ff:ff:ff 接收信息: 接收报文:5079 字节:1657655 errors:0 dropped:0 multicast:0 collisions:0 length:0 over:0 crc:0 frame:0 fifo:0 missed:0 发送信息: 发送报文:4520 字节:693301 errors:0 dropped:0 aborted:0 carrier:0 fifo:0 heartbeat:0 window:0