一直以来我们获取IP地址方法都是直接百度一查，或者老代码里就已经存在这部分代码然后直接使用。今天归纳一下常见的两种方法以及如何选择：
方式一：
代码语言：javascript复制#import <sys/socket.h>
#import <sys/sockio.h>
#import <sys/ioctl.h>
#import <ifaddrs.h>
#import <arpa/inet.h>
- (NSString *)getIPAddress {
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
NSMutableArray *ips = [NSMutableArray array];
int BUFFERSIZE = 4096;
struct ifconf ifc;
char buffer[BUFFERSIZE], *ptr, lastname[IFNAMSIZ], *cptr;
struct ifreq *ifr, ifrcopy;
ifc.ifc_len = BUFFERSIZE;
ifc.ifc_buf = buffer;
if (ioctl(sockfd, SIOCGIFCONF, &ifc) >= 0) {
for (ptr = buffer; ptr < buffer ifc.ifc_len; ) {
ifr = (struct ifreq *)ptr;
int len = sizeof(struct sockaddr);
if (ifr->ifr_addr.sa_len > len) {
len = 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);
if ((ifrcopy.ifr_flags & IFF_UP) == 0) continue;
NSString *ip = [NSString stringWithFormat:@"%s",inet_ntoa(((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr)];
[ips addObject:ip];
}
}
close(sockfd);
NSString *deviceIP = @"";
for (int i = 0; i < ips.count; i ) {
if(ips.count > 0) {
deviceIP = [NSString stringWithFormat:@"%@", ips.lastObject];
}
}
return deviceIP;
}方式二：
代码语言：javascript复制#import <ifaddrs.h>
#import <arpa/inet.h>
#import <net/if.h>
#define IOS_CELLULAR @"pdp_ip0"
#define IOS_WIFI @"en0"
#define IOS_VPN @"utun0"
#define IP_ADDR_IPv4 @"ipv4"
#define IP_ADDR_IPv6 @"ipv6"
- (NSString *)getLocalIPAddress:(BOOL)preferIPv4 {
NSArray *searchArray = preferIPv4 ?
@[ IOS_VPN @"/" IP_ADDR_IPv4, IOS_VPN @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6 ] :
@[ IOS_VPN @"/" IP_ADDR_IPv6, IOS_VPN @"/" IP_ADDR_IPv4, IOS_WIFI @"/" IP_ADDR_IPv6, IOS_WIFI @"/" IP_ADDR_IPv4, IOS_CELLULAR @"/" IP_ADDR_IPv6, IOS_CELLULAR @"/" IP_ADDR_IPv4 ] ;
NSDictionary *addresses = [self getIPAddresses];
NSLog(@"addresses: %@", addresses);
__block NSString *address;
[searchArray enumerateObjectsUsingBlock:^(NSString *key, NSUInteger idx, BOOL *stop) {
address = addresses[key];
//筛选出IP地址格式
if([self isValidatIP:address]) *stop = YES;
} ];
return address ? address : @"0.0.0.0";
}
- (BOOL)isValidatIP:(NSString *)ipAddress {
if (ipAddress.length == 0) {
return NO;
}
NSString *urlRegEx = @"^([01]?\d\d?|2[0-4]\d|25[0-5])\."
"([01]?\d\d?|2[0-4]\d|25[0-5])\."
"([01]?\d\d?|2[0-4]\d|25[0-5])\."
"([01]?\d\d?|2[0-4]\d|25[0-5])$";
NSError *error;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:urlRegEx options:0 error:&error];
if (regex != nil) {
NSTextCheckingResult *firstMatch=[regex firstMatchInString:ipAddress options:0 range:NSMakeRange(0, [ipAddress length])];
if (firstMatch) {
NSRange resultRange = [firstMatch rangeAtIndex:0];
NSString *result=[ipAddress substringWithRange:resultRange];
//输出结果
NSLog(@"%@",result);
return YES;
}
}
return NO;
}
- (NSDictionary *)getIPAddresses {
NSMutableDictionary *addresses = [NSMutableDictionary dictionaryWithCapacity:8];
// retrieve the current interfaces - returns 0 on success
struct ifaddrs *interfaces;
if(!getifaddrs(&interfaces)) {
// Loop through linked list of interfaces
struct ifaddrs *interface;
for(interface=interfaces; interface; interface=interface->ifa_next) {
if(!(interface->ifa_flags & IFF_UP) /* || (interface->ifa_flags & IFF_LOOPBACK) */ ) {
continue; // deeply nested code harder to read
}
const struct sockaddr_in *addr = (const struct sockaddr_in*)interface->ifa_addr;
char addrBuf[ MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) ];
if(addr && (addr->sin_family==AF_INET || addr->sin_family==AF_INET6)) {
NSString *name = [NSString stringWithUTF8String:interface->ifa_name];
NSString *type;
if(addr->sin_family == AF_INET) {
if(inet_ntop(AF_INET, &addr->sin_addr, addrBuf, INET_ADDRSTRLEN)) {
type = IP_ADDR_IPv4;
}
} else {
const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6*)interface->ifa_addr;
if(inet_ntop(AF_INET6, &addr6->sin6_addr, addrBuf, INET6_ADDRSTRLEN)) {
type = IP_ADDR_IPv6;
}
}
if(type) {
NSString *key = [NSString stringWithFormat:@"%@/%@", name, type];
addresses[key] = [NSString stringWithUTF8String:addrBuf];
}
}
}
// Free memory
freeifaddrs(interfaces);
}
return [addresses count] ? addresses : nil;
}正常使用都没有大问题，方式二多了一些功能，多了一些校验，只是使用 UBSan 分析时，方式一会报一下内存问题，都是指针错位没有字节对齐之类的相关检测报错。
UBSan.jpg
这些报错虽然不会直接导致问题，但是按照苹果官方的描述，可能导致崩溃或性能下降：
Misaligned Pointer (错位的指针) Detects when code accesses a misaligned pointer or creates a misaligned reference. 检测代码何时访问错位的指针或创建错位的引用。 Overview In Xcode 9 and later, you can use this check to detect reads from, or writes to, a misaligned pointer, or when you create a misaligned reference. A pointer misaligns if its address isn’t a multiple of its type’s alignment. Dereferencing a misaligned pointer has undefined behavior, and may result in a crash or degraded performance. Alignment violations occur frequently in code that serializes or deserializes data. Avoid this issue by using a serialization format that preserves data alignment. 在Xcode 9和之后更高版本中，你可以使用这个检查来检测从一个错位的指针读取或写入，或者当你创建一个错位的引用时，如果一个指针的地址不是其类型对齐的倍数，那么它就会出现错位。解除一个错位的指针有未定义的行为，并可能导致崩溃或性能下降。 在序列化或反序列化数据的代码中，经常发生违反对齐方式的情况。通过使用保留数据对齐的序列化格式来避免这个问题。
所以综上还是建议使用方式二来获取ID地址（都是本地地址），要获取公网地址可以使用淘宝的API：
代码语言：javascript复制- (NSString *)getNetworkIPAddress {
//方式一：淘宝api
NSURL *ipURL = [NSURL URLWithString:@"http://ip.taobao.com/service/getIpInfo.php?ip=myip"];
NSData *data = [NSData dataWithContentsOfURL:ipURL];
NSDictionary *ipDic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];
NSString *ipStr = nil;
if (ipDic && [ipDic[@"code"] integerValue] == 0) {
//获取成功
ipStr = ipDic[@"data"][@"ip"];
}
return (ipStr ? ipStr : @"0.0.0.0");
}
