Questions

在[iOS實現WIFI傳書]中有一個獲取IP的步驟
在此順帶總結一份關于WIFI與IP的常用內容

1. 設備網絡IP地址
2. WiFi信息
3. 路由器地址
4. 本機DNS服務器
5. 手機的網絡IP地址
6. 進入WiFi設置

Code

• 設備網絡IP地址

// 獲取設備網絡Ip地址
+ (NSString *)deviceNetIp {
    int sockfd =socket(AF_INET,SOCK_DGRAM,0);
    // if (sockfd < 0) return nil;
    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;
}

• WiFi信息

/*
 * 獲取wifi信息
 * iOS12以上的版本獲取wifi信息糕韧，需在中設Capability置Access WIFI Infomation = ON
 * iOS13獲取之前需獲判斷是否同意app適用地理位置信息
 */
- (void)wifi:(void(^)(NSDictionary *sender))handler {
    if (@available(iOS 13.0, *)) {
        if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusDenied) {
            // 設置定位權限
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString] options:@{} completionHandler:nil];
        } else if ([CLLocationManager authorizationStatus] == kCLAuthorizationStatusNotDetermined) {
            self.manager = [[CLLocationManager alloc] init];
            self.manager.delegate = self;
            [self.manager requestWhenInUseAuthorization];
            self.wifiBlock = handler;
        } else {
            [self fetchWifi:handler];
        }
    } else {
        [self fetchWifi:handler];
    }
}
- (void)fetchWifi:(void(^)(NSDictionary *sender))handler {
    NSArray *interfaceNames = CFBridgingRelease(CNCopySupportedInterfaces());
    NSDictionary *SSIDInfo;
    for (NSString *interfaceName in interfaceNames) {
        SSIDInfo = CFBridgingRelease(CNCopyCurrentNetworkInfo((__bridge CFStringRef)interfaceName));
        BOOL isNotEmpty = (SSIDInfo.count > 0);
        if (isNotEmpty) {
            break;
        }
    }
    // ssid信息 即wifi名稱
    NSString *ssid = [SSIDInfo objectForKey:@"SSID"];
    // bssid信息 即mac地址
    NSString *bssid = [SSIDInfo objectForKey:@"BSSID"];
    NSLog(@"ssid = %@, mac地址 = %@", ssid, bssid);
    if (handler) {
        handler(SSIDInfo);
    }
}

• 路由器信息

+ (NSString *)routerIp {
    NSString *address = @"error";
    struct ifaddrs *interfaces = NULL;
    struct ifaddrs *temp_addr = NULL;
    int success = 0;
    success = getifaddrs(&interfaces);
    if (success == 0) {
        temp_addr = interfaces;
        while(temp_addr != NULL){
            if(temp_addr->ifa_addr->sa_family == AF_INET) {
                if([[NSString stringWithUTF8String:temp_addr->ifa_name] isEqualToString:@"en0"]) {
                    address = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    NSLog(@"廣播地址--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)]);
                    NSLog(@"本機地址--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)]);
                    NSLog(@"子網掩碼地址--%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)]);
                    NSLog(@"interface--%@",[NSString stringWithUTF8String:temp_addr->ifa_name]);
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    
    // Free memory
    freeifaddrs(interfaces);
    
    in_addr_t i = inet_addr([address cStringUsingEncoding:NSUTF8StringEncoding]);
    in_addr_t* x = &i;
    unsigned char *s = getdefaultgateway(x);
    NSString *ip=[NSString stringWithFormat:@"%d.%d.%d.%d",s[0],s[1],s[2],s[3]];
    free(s);

    return ip;
}

• DNS服務器

// 獲取本機DNS服務器
+ (NSString *)dnsServers {
    res_state res = malloc(sizeof(struct __res_state));
    int result = res_ninit(res);
    NSMutableArray *dnsArray = @[].mutableCopy;
    if ( result == 0 ) {
        for ( int i = 0; i < res->nscount; i++ ) {
            NSString *s = [NSString stringWithUTF8String :  inet_ntoa(res->nsaddr_list[i].sin_addr)];
            [dnsArray addObject:s];
        }
    } else {
        NSLog(@"%@",@" res_init result != 0");
    }
    res_nclose(res);
    return dnsArray.firstObject;
}

• 手機的網絡IP地址

+ (NSString *)phoneInNetIp {
    BOOL success;
    struct ifaddrs * addrs;
    const struct ifaddrs * cursor;
    success = getifaddrs(&addrs) == 0;
    if (success) {
        cursor = addrs;
        while (cursor != NULL) {
            // the second test keeps from picking up the loopback address
            if (cursor->ifa_addr->sa_family == AF_INET && (cursor->ifa_flags & IFF_LOOPBACK) == 0) {
                NSString *name = [NSString stringWithUTF8String:cursor->ifa_name];
                if ([name isEqualToString:@"en0"]) // Wi-Fi adapter
                    NSLog(@"IP:%@",[NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)]);
                return [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)cursor->ifa_addr)->sin_addr)];
            }
            cursor = cursor->ifa_next;
        }
        freeifaddrs(addrs);
    }
    return nil;
}

• WiFi設置

NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
    [[UIApplication sharedApplication] openURL:url options:@{} completionHandler:nil];
}

Over

多說兩句：多數時候解決問題需要找思路跪腹，一旦確定有解拦坠，要實現的就是Code渐苏。代碼不是最全破婆，網絡不少人已貼出來匈挖，在此不多寫兄猩。