Question

我做小型iPhone应用程序，我需要获得IP范围并使用目标C迭代它。我可以获得本地IP，网络掩码。我也在SO解决方案上找到了如何获得广播地址。但是我怎样才能获得网络地址？通过了解本地网络中的第一个网络地址和本地网络中的最后一个广播地址，我想迭代该范围内的所有IP。只需调用它并查看响应即可。我怎样才能做到这一点？

从https://stackoverflow.com/a/21077257

获取广播的解决方案

#include <net/ethernet.h>
#include <arpa/inet.h>

NSString *localIPAddress = @"192.168.1.10";
NSString *netmaskAddress = @"255.255.192.0";

// Strings to in_addr:
struct in_addr localAddr;
struct in_addr netmaskAddr;
inet_aton([localIPAddress UTF8String], &localAddr);
inet_aton([netmaskAddress UTF8String], &netmaskAddr);

// The broadcast address calculation:
localAddr.s_addr |= ~(netmaskAddr.s_addr);

// in_addr to string:
NSString *broadCastAddress = [NSString stringWithUTF8String:inet_ntoa(localAddr)];

更新：来自netmaskAddress我可以获得网络中的主机数量。我只需要使用IP。现在的问题是如何从给定的IP获得下一个IP？例如，我有

NSString *ip = "192.168.1.5"

如何使用目标C获得“192.168.1.6”？

Answer 1

我不建议对这种IP（in_addr）进行位操作，因为如果你看看里面的字节是反向排序的。

下面的代码是打印设备IP，网络IP，网络掩码和广播地址以及网络范围内的所有IP。它可能会有所帮助。享受！

NetworkInformation *network = [[NetworkInformation alloc] init];
NSLog(@"%@", network);
for(NSString *ip in network.ipsInRange){
    NSLog(@"ip: %@", ip);
}

NetworkInformation.h

#import <Foundation/Foundation.h>

@interface NetworkInformation : NSObject
@property (nonatomic, retain) NSString *deviceIP;
@property (nonatomic, retain) NSString *netmask;
@property (nonatomic, retain) NSString *address;
@property (nonatomic, retain) NSString *broadcast;
@property (nonatomic, retain) NSArray *ipsInRange;
- (void)updateData;
- (NSString *)description;
@end

NetworkInformation.m

#import "NetworkInformation.h"
#import <arpa/inet.h>
#import <ifaddrs.h>

@implementation NetworkInformation

- (id)init {
    self = [super init];
    if (self) {
        [self updateData];
    }
    return self;
}

-(void)updateData {
    [self updateDataFromWifiNetwork];
    self.address = [self getNetworkAddress];
    self.ipsInRange = [self getIPsInRange];
}

- (void)updateDataFromWifiNetwork {
    self.deviceIP = nil;
    self.netmask = nil;
    self.broadcast = nil;
    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"]){
                    self.deviceIP = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_addr)->sin_addr)];
                    self.netmask = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_netmask)->sin_addr)];
                    self.broadcast = [NSString stringWithUTF8String:inet_ntoa(((struct sockaddr_in *)temp_addr->ifa_dstaddr)->sin_addr)];
                }
            }
            temp_addr = temp_addr->ifa_next;
        }
    }
    freeifaddrs(interfaces);
    if(!self.deviceIP || !self.netmask){
        NSLog(@"error in updateDataFromWifiNetwork, device ip: %@ netmask: %@", self.deviceIP, self.netmask);
    }
}

-(NSString*)getNetworkAddress {
    if(!self.deviceIP || !self.netmask){
        return nil;
    }
    unsigned int address = [self convertSymbolicIpToNumeric:self.deviceIP];
    address &= [self convertSymbolicIpToNumeric:self.netmask];
    return [self convertNumericIpToSymbolic:address];
}

-(NSArray*)getIPsInRange {
    unsigned int address = [self convertSymbolicIpToNumeric:self.address];
    unsigned int netmask = [self convertSymbolicIpToNumeric:self.netmask];
    NSMutableArray *result = [[NSMutableArray alloc] init];
    int numberOfBits;
    for (numberOfBits = 0; numberOfBits < 32; numberOfBits++) {
        if ((netmask << numberOfBits) == 0){
            break;
        }
    }
    int numberOfIPs = 0;
    for (int n = 0; n < (32 - numberOfBits); n++) {
        numberOfIPs = numberOfIPs << 1;
        numberOfIPs = numberOfIPs | 0x01;
    }
    for (int i = 1; i < (numberOfIPs) && i < numberOfIPs; i++) {
        unsigned int ourIP = address + i;
        NSString *ip = [self convertNumericIpToSymbolic:ourIP];
        [result addObject:ip];
    }
    return result;
}

-(NSString*)convertNumericIpToSymbolic:(unsigned int)numericIP {
    NSMutableString *sb = [NSMutableString string];
    for (int shift = 24; shift > 0; shift -= 8) {
        [sb appendString:[NSString stringWithFormat:@"%d", (numericIP >> shift) & 0xff]];
        [sb appendString:@"."];
    }
    [sb appendString:[NSString stringWithFormat:@"%d", (numericIP & 0xff)]];
    return sb;
}

-(unsigned int)convertSymbolicIpToNumeric:(NSString*)symbolicIP {
    NSArray *st = [symbolicIP componentsSeparatedByString: @"."];
    if (st.count != 4){
        NSLog(@"error in convertSymbolicIpToNumeric, splited string count: %lu", st.count);
        return 0;
    }
    int i = 24;
    int ipNumeric = 0;
    for (int n = 0; n < st.count; n++) {
        int value = [(NSString*)st[n] intValue];
        if (value != (value & 0xff)) {
            NSLog(@"error in convertSymbolicIpToNumeric, invalid IP address: %@", symbolicIP);
            return 0;
        }
        ipNumeric += value << i;
        i -= 8;
    }
    return ipNumeric;
}

-(NSString*)description {
    return [NSString stringWithFormat: @"\nip:%@\nnetmask:%@\nnetwork:%@\nbroadcast:%@", self.deviceIP, self.netmask, self.address, self.broadcast];
}

@end

获取目标C的ip范围

1 个答案: