Getting ARP table on iPhone/iPad
arp, ios, objective-c, xcode
Solution
After importing <netinet/if_ether.h>, you should edit it and change the line
#include <net/if_arp.h>
to
#include "if_arp.h"
and then import <net/if_arp.h> in your project as well. This should fix that error.
Anyway the headers you need to import to compile the code you posted are:
#include "if_ether.h"
#include "route.h"
#include "if_arp.h"
#include "if_dl.h"
Hope this helps =)
EDIT:
You need to "Add files to project", not simply importing it with #import or #include. You can find above files from following links: Files under "netinet" Files under "net"
Problem
I am trying to get the ARP entries on my iPad like here. When compiling the code to run on my iPad (so not the simulator) I am getting missing header error messages. You can resolve them by copying the header files into you project locally as mentioned in this post. The problem lies in the line sdl = (struct sockaddr_dl *)(sin + 1); in this piece of code: ``` -(NSString*) ip2mac: (char*) ip { int expire_time, flags, export_only, doing_proxy, found_entry; NSString *mAddr = nil; u_long addr = inet_addr(ip); int mib[6]; size_t needed; char *host, *lim, *buf, *next; struct rt_msghdr *rtm; struct sockaddr_inarp *sin; struct sockaddr_dl *sdl; extern int h_errno; struct hostent *hp; mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = AF_INET; mib[4] = NET_RT_FLAGS; mib[5] = RTF_LLINFO; if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) err(1, "route-sysctl-estimate"); if ((buf = malloc(needed)) == NULL) err(1, "malloc"); if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) err(1, "actual retrieval of routing table"); lim = buf + needed; for (next = buf; next < lim; next += rtm->rtm_msglen) { rtm = (struct rt_msghdr *)next; sin = (struct sockaddr_inarp *)(rtm + 1); sdl = (struct sockaddr_dl *)(sin + 1); if (addr) { if (addr != sin->sin_addr.s_addr) continue; found_entry = 1; } if (nflag == 0) hp = gethostbyaddr((caddr_t)&(sin->sin_addr), sizeof sin->sin_addr, AF_INET); else hp = 0; if (hp) host = hp->h_name; else { host = "?"; if (h_errno == TRY_AGAIN) nflag = 1; } if (sdl->sdl_alen) { u_char *cp = LLADDR(sdl); mAddr = [NSString stringWithFormat:@"%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]]; // ether_print((u_char *)LLADDR(sdl)); } else mAddr = nil; } if (found_entry == 0) { return nil; } else { return mAddr; } } ``` It gives the following error message: Arithmetic on pointer to incomplete type 'struct sockaddr_inarp*' When you compile the code for the iPad simulator everything runs fine. Does anyone have an idea how to solve this? A similar question (but not solved) is asked here.