IOCTL获取和配置IP地址/子网掩码/网关

TIPS：部分代码摘自网上，代码已测试通过。

#include <sys/socket.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <stdio.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <ctype.h>
#include <net/route.h>
#include <fcntl.h>
#include <string.h>
#include <pthread.h>
#if defined(__GLIBC__) && __GLIBC__ >=2 && __GLIBC_MINOR__ >= 1
#include <netpacket/packet.h>
#include <net/ethernet.h>
#else
#include <sys/types.h>
#include <netinet/if_ether.h>
#endif#include "xxx_ip.h"static int set_addr(unsigned char ip[16], int flag);
static int get_addr(unsigned char ip[16], int flag);int get_ip(unsigned char ip[16])
{return get_addr(ip, SIOCGIFADDR);
}int get_ip_netmask(unsigned char ip[16])
{return get_addr(ip, SIOCGIFNETMASK);
}int get_mac(unsigned char addr[6])
{return get_addr(addr, SIOCGIFHWADDR);
}static int get_addr(unsigned char *addr, int flag)
{SINT32 sockfd = 0;struct sockaddr_in *sin;struct ifreq ifr;if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0){perror("socket error!\n");return FALSE;}memset(&ifr, 0, sizeof(ifr));snprintf(ifr.ifr_name, (sizeof(ifr.ifr_name) - 1), "%s", DEFAULT_ETH);if(ioctl(sockfd, flag, &ifr) < 0 ){perror("ioctl error!\n");close(sockfd);return FALSE;}close(sockfd);if (SIOCGIFHWADDR == flag){memcpy((void *)addr, (const void *)&ifr.ifr_ifru.ifru_hwaddr.sa_data, 6);/*printf("mac address: %2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x\n", addr[0],addr[1],addr[2],addr[3],addr[4],addr[5]);*/}else{sin = (struct sockaddr_in *)&ifr.ifr_addr;snprintf((char *)addr, IP_LENGTH, "%s", inet_ntoa(sin->sin_addr));}return TRUE;
}int is_valid_ip(unsigned char ipaddr[16])
{int ret = 0;struct in_addr inp;ret = inet_aton(ipaddr, &inp);if (0 == ret){return FALSE;}else{printf("inet_aton:ip=%lu\n",ntohl(inp.s_addr));}return TRUE;
}/** 先验证是否为合法IP，然后将掩码转化成32无符号整型，取反为000...00111...1，* 然后再加1为00...01000...0，此时为2^n，如果满足就为合法掩码** */
int is_valid_netmask(unsigned char netmask[16])
{if(is_valid_ip(netmask) > 0){unsigned int b = 0, i, n[4];sscanf(netmask, "%u.%u.%u.%u", &n[3], &n[2], &n[1], &n[0]);for(i = 0; i < 4; ++i) //将子网掩码存入32位无符号整型b += n[i] << (i * 8);b = ~b + 1;if((b & (b - 1)) == 0) //判断是否为2^nreturn TRUE;}return FALSE;
}int set_ip_netmask(unsigned char ip[16])
{return set_addr(ip, SIOCSIFNETMASK);
}int set_ip(unsigned char ip[16])
{return set_addr(ip, SIOCSIFADDR);
}static int set_addr(unsigned char ip[16], int flag)
{struct ifreq ifr;struct sockaddr_in sin;int sockfd;if (is_valid_ip(ip) < 0){printf("ip was invalid!\n");return FALSE;}sockfd = socket(AF_INET, SOCK_DGRAM, 0);if(sockfd == -1){fprintf(stderr, "Could not get socket.\n");perror("eth0\n");return FALSE;}snprintf(ifr.ifr_name, (sizeof(ifr.ifr_name) - 1), "%s", DEFAULT_ETH);/* Read interface flags */if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) < 0) {fprintf(stderr, "ifdown: shutdown ");perror(ifr.ifr_name);return FALSE;}memset(&sin, 0, sizeof(struct sockaddr));sin.sin_family = AF_INET;inet_aton(ip, &sin.sin_addr.s_addr);memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));if (ioctl(sockfd, flag, &ifr) < 0){fprintf(stderr, "Cannot set IP address. ");perror(ifr.ifr_name);return FALSE;}return TRUE;
}int set_gateway(unsigned char ip[16])
{int sockFd;struct sockaddr_in sockaddr;struct rtentry rt;if (is_valid_ip(ip) < 0){printf("gateway was invalid!\n");return FALSE;}sockFd = socket(AF_INET, SOCK_DGRAM, 0);if (sockFd < 0){perror("Socket create error.\n");return FALSE;}memset(&rt, 0, sizeof(struct rtentry));memset(&sockaddr, 0, sizeof(struct sockaddr_in));sockaddr.sin_family = AF_INET;sockaddr.sin_port = 0;if(inet_aton(ip, &sockaddr.sin_addr)<0){perror("inet_aton error\n" );close(sockFd);return FALSE;}memcpy ( &rt.rt_gateway, &sockaddr, sizeof(struct sockaddr_in));((struct sockaddr_in *)&rt.rt_dst)->sin_family=AF_INET;((struct sockaddr_in *)&rt.rt_genmask)->sin_family=AF_INET;rt.rt_flags = RTF_GATEWAY;if (ioctl(sockFd, SIOCADDRT, &rt)<0){perror("ioctl(SIOCADDRT) error in set_default_route\n");close(sockFd);return FALSE;}return TRUE;
}