这是我编写的一些代码，用于查找机器的路由。 我从netstat代码中复制了系统调用。请注意，他们强烈建议不要这样做，因为这些系统调用不是受支持的API，可能随时更改。他们建议我只解析netstat的输出。
CustomRoute.c：
#import "CustomRoute.h"
@implementation CustomRoute
+ (NSMutableArray*) getRoutes
{
NSMutableArray* routeArray = [NSMutableArray array];
CustomRoute* route = nil;
size_t needed;
int mib[6];
char *buf, *next, *lim;
register struct rt_msghdr2 *rtm;
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = 0;
mib[4] = NET_RT_DUMP2;
mib[5] = 0;
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
err(1, "sysctl: net.route.0.0.dump estimate");
}
if ((buf = malloc(needed)) == 0) {
err(2, "malloc(%lu)", (unsigned long)needed);
}
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
err(1, "sysctl: net.route.0.0.dump");
}
lim = buf + needed;
for (next = buf; next < lim; next += rtm->rtm_msglen) {
rtm = (struct rt_msghdr2 *)next;
route = [self getRoute:rtm];
if(route != nil)
{
[routeArray addObject:route];
}
}
free(buf);
printf("Total routes: %u\n", [routeArray count]);
return routeArray;
}
+ (CustomRoute*) getRoute:(struct rt_msghdr2 *)rtm
{
struct sockaddr* dst_sa = (struct sockaddr *)(rtm + 1);
CustomRoute* route = nil;
if(rtm->rtm_addrs & RTA_DST)
{
switch(dst_sa->sa_family)
{
case AF_INET:
if(dst_sa->sa_family == AF_INET && !((rtm->rtm_flags & RTF_WASCLONED) && (rtm->rtm_parentflags & RTF_PRCLONING)))
{
route = [[CustomRoute alloc] initWithRtm:rtm];
}
break;
}
}
return route;
}
-(void) setAddr:(struct sockaddr*)sa index:(int)rtax_index
{
if(rtax_index >= 0 && rtax_index < RTAX_MAX)
{
memcpy(&(m_addrs[rtax_index]), sa, sizeof(struct sockaddr));
}
}
-(NSString*) getDestination
{
return [self getAddrStringByIndex:RTAX_DST];
}
-(NSString*) getNetmask
{
return [self getAddrStringByIndex:RTAX_NETMASK];
}
-(NSString*) getGateway
{
return [self getAddrStringByIndex:RTAX_GATEWAY];
}
-(NSString*) getDetails
{
NSMutableString* result = [[NSMutableString alloc] init];
[result appendFormat: [NSString stringWithFormat: @"message type: 0x%06x\n", m_rtm.rtm_type]];
[result appendFormat: [NSString stringWithFormat: @"flags: 0x%06x\n", m_rtm.rtm_flags]];
[result appendFormat: [NSString stringWithFormat: @"addrs: 0x%06x\n", m_rtm.rtm_addrs]];
return result;
}
-initWithRtm: (struct rt_msghdr2*) rtm
{
int i;
struct sockaddr* sa = (struct sockaddr*)(rtm + 1);
memcpy(&(m_rtm), rtm, sizeof(struct rt_msghdr2));
for(i = 0; i < RTAX_MAX; i++)
{
[self setAddr:&(sa[i]) index:i];
}
return self;
}
- init
{
memset(m_addrs, 0, sizeof(m_addrs));
return self;
}
@end
@implementation CustomRoute (Private)
-(NSString*) getAddrStringByIndex: (int)rtax_index
{
NSString * routeString = nil;
struct sockaddr* sa = &(m_addrs[rtax_index]);
int flagVal = 1 << rtax_index;
if(!(m_rtm.rtm_addrs & flagVal))
{
return @"none";
}
if(rtax_index >= 0 && rtax_index < RTAX_MAX)
{
switch(sa->sa_family)
{
case AF_INET:
{
struct sockaddr_in* si = (struct sockaddr_in *)sa;
if(si->sin_addr.s_addr == INADDR_ANY)
routeString = @"default";
else
routeString = [NSString stringWithCString:(char *)inet_ntoa(si->sin_addr) encoding:NSASCIIStringEncoding];
}
break;
case AF_LINK:
{
struct sockaddr_dl* sdl = (struct sockaddr_dl*)sa;
if(sdl->sdl_nlen + sdl->sdl_alen + sdl->sdl_slen == 0)
{
routeString = [NSString stringWithFormat: @"link #%d", sdl->sdl_index];
}
else
routeString = [NSString stringWithCString:link_ntoa(sdl) encoding:NSASCIIStringEncoding];
}
break;
default:
{
char a[3 * sa->sa_len];
char *cp;
char *sep = "";
int i;
if(sa->sa_len == 0)
{
routeString = @"empty";
}
else
{
a[0] = (char)NULL;
for(i = 0, cp = a; i < sa->sa_len; i++)
{
cp += sprintf(cp, "%s%02x", sep, (unsigned char)sa->sa_data[i]);
sep = ":";
}
routeString = [NSString stringWithCString:a encoding:NSASCIIStringEncoding];
}
}
}
}
return routeString;
}
@end
CustomRoute.h:
#import <Cocoa/Cocoa.h>
#import <net/route.h>
#import <sys/socket.h>
#import <netinet/in.h>
#import <net/if_dl.h>
#import <sys/sysctl.h>
@interface CustomRoute : NSObject {
struct sockaddr m_addrs[RTAX_MAX];
struct rt_msghdr2 m_rtm;
int m_len;
}
+ (NSMutableArray*) getRoutes;
+ (CustomRoute*) getRoute:(struct rt_msghdr2 *)rtm;
- (void) setAddr:(struct sockaddr*)sa index:(int)rtax_index;
- (NSString*) getDestination;
- (NSString*) getNetmask;
- (NSString*) getGateway;
- initWithRtm: (struct rt_msghdr2*) rtm;
@end
