获取IP地址

IPAddress.h

 

#define MAXADDRS    32  

extern char *if_names[MAXADDRS];  
extern char *ip_names[MAXADDRS];  
extern char *hw_addrs[MAXADDRS];  
extern unsigned long ip_addrs[MAXADDRS];  

void InitAddresses();  
void FreeAddresses();  
void GetIPAddresses();  
void GetHWAddresses();

 

IPAddress.c

 

#include "IPAddress.h"  

#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 
#include <unistd.h> 
#include <sys/ioctl.h> 
#include <sys/types.h> 
#include <sys/socket.h> 
#include <netinet/in.h> 
#include <netdb.h> 
#include <arpa/inet.h> 
#include <sys/sockio.h> 
#include <net/if.h> 
#include <errno.h> 
#include <net/if_dl.h> 

#define    min(a,b)    ((a) < (b) ? (a) : (b))  
#define    max(a,b)    ((a) > (b) ? (a) : (b))  

#define BUFFERSIZE    4000  

char *if_names[MAXADDRS];  
char *ip_names[MAXADDRS];  
char *hw_addrs[MAXADDRS];  
unsigned long ip_addrs[MAXADDRS];  

static int   nextAddr = 0;  

void InitAddresses() {  
    int i;  
    for (i = 0; i < MAXADDRS; ++i) {  
        if_names[i] = ip_names[i] = hw_addrs[i] = NULL;  
        ip_addrs[i] = 0;  
    }  
}  

void FreeAddresses() {  
    int i;  
    for (i=0; i<MAXADDRS; ++i) {  
        if (if_names[i] != 0) free(if_names[i]);  
        if (ip_names[i] != 0) free(ip_names[i]);  
        if (hw_addrs[i] != 0) free(hw_addrs[i]);  
        ip_addrs[i] = 0;  
    }  
    InitAddresses();  
}  

void GetIPAddresses() {  
    int i, len, flags;  
    char buffer[BUFFERSIZE], *ptr, lastname[IFNAMSIZ], *cptr;  
    struct ifconf ifc;  
    struct ifreq *ifr, ifrcopy;  
    struct sockaddr_in *sin;  
    
    char temp[80];  
    
    int sockfd;  
    
    for (i = 0; i < MAXADDRS; ++i) {  
        if_names[i] = ip_names[i] = NULL;  
        ip_addrs[i] = 0;  
    }  
    
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);  
    if (sockfd < 0) {  
        perror("socket failed");  
        return;  
    }  
    
    ifc.ifc_len = BUFFERSIZE;  
    ifc.ifc_buf = buffer;  
    
    if (ioctl(sockfd, SIOCGIFCONF, &ifc) < 0) {  
        perror("ioctl error");  
        return;  
    }  
    
    lastname[0] = 0;  
    
    for (ptr = buffer; ptr < buffer + ifc.ifc_len; ) {  
        ifr = (struct ifreq *)ptr;  
        len = max(sizeof(struct sockaddr), ifr->ifr_addr.sa_len);  
        ptr += sizeof(ifr->ifr_name) + len;     
        
        if (ifr->ifr_addr.sa_family != AF_INET) {  
            continue;      
        }  
        
        if ((cptr = (char *)strchr(ifr->ifr_name, ':')) != NULL) {  
            *cptr = 0;        
        }  
        
        if (strncmp(lastname, ifr->ifr_name, IFNAMSIZ) == 0) {  
            continue;      
        }  
        
        memcpy(lastname, ifr->ifr_name, IFNAMSIZ);  
        
        ifrcopy = *ifr;  
        ioctl(sockfd, SIOCGIFFLAGS, &ifrcopy);  
        flags = ifrcopy.ifr_flags;  
        if ((flags & IFF_UP) == 0) {  
            continue;      
        }  
        
        if_names[nextAddr] = (char *)malloc(strlen(ifr->ifr_name)+1);  
        if (if_names[nextAddr] == NULL) {  
            return;  
        }  
        strcpy(if_names[nextAddr], ifr->ifr_name);  
        
        sin = (struct sockaddr_in *)&ifr->ifr_addr;  
        strcpy(temp, inet_ntoa(sin->sin_addr));  
        
        ip_names[nextAddr] = (char *)malloc(strlen(temp) + 1);  
        if (ip_names[nextAddr] == NULL) {  
            return;  
        }  
        strcpy(ip_names[nextAddr], temp);  
        
        ip_addrs[nextAddr] = sin->sin_addr.s_addr;  
        
        ++nextAddr;  
    }  
    
    close(sockfd);  
}  

void GetHWAddresses() {  
    struct ifconf ifc;  
    struct ifreq *ifr;  
    int i, sockfd;  
    char buffer[BUFFERSIZE], *cp, *cplim;  
    char temp[80];  
    
    for (i = 0; i < MAXADDRS; ++i) {  
        hw_addrs[i] = NULL;  
    }  
    
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);  
    if (sockfd < 0) {  
        perror("socket failed");  
        return;  
    }  
    
    ifc.ifc_len = BUFFERSIZE;  
    ifc.ifc_buf = buffer;  
    
    if (ioctl(sockfd, SIOCGIFCONF, (char *)&ifc) < 0) {  
        perror("ioctl error");  
        close(sockfd);  
        return;  
    }  
    
    ifr = ifc.ifc_req;  
    
    cplim = buffer + ifc.ifc_len;  
    
    for (cp = buffer; cp < cplim; ) {  
        ifr = (struct ifreq *)cp;  
        if (ifr->ifr_addr.sa_family == AF_LINK) {  
            struct sockaddr_dl *sdl = (struct sockaddr_dl *)&ifr->ifr_addr;  
            int a,b,c,d,e,f;  
            int i;  
            
            strcpy(temp, (char *)ether_ntoa(LLADDR(sdl)));  
            sscanf(temp, "%x:%x:%x:%x:%x:%x", &a, &b, &c, &d, &e, &f);  
            sprintf(temp, "%02X:%02X:%02X:%02X:%02X:%02X",a,b,c,d,e,f);  
            
            for (i = 0; i < MAXADDRS; ++i) {  
                if ((if_names[i] != NULL) && (strcmp(ifr->ifr_name,if_names[i]) == 0)) {  
                    if (hw_addrs[i] == NULL) {  
                        hw_addrs[i] = (char *)malloc(strlen(temp) + 1);  
                        strcpy(hw_addrs[i], temp);  
                        break;  
                    }  
                }  
            }  
        }  
        cp += sizeof(ifr->ifr_name) + max(sizeof(ifr->ifr_addr), ifr->ifr_addr.sa_len);  
    }  
    close(sockfd);  
} 

 

示例：

 

- (NSString *)deviceIPAdress {  
    InitAddresses();  
    GetIPAddresses();  
    GetHWAddresses();  
    return [NSString stringWithFormat:@"%s", ip_names[1]];  
} 

- (void)viewDidLoad {
	NSString* address = [self deviceIPAdress];
	NSString* myIPAdress = [NSString stringWithFormat:@"IP Address: %@", address];
	textView.text = myIPAdress;
}