从FreeBSD4.5的arp命令的源代码中获得，可以在macos10.6上编译，运行。 gcc -o arp -Wall arp.c #include <sys/param.h>#include <sys/file.h>#include <sys/socket.h>#include <sys/sockio.h>#include <sys/sysctl.h>#include <sys/ioctl.h>#include <sys/time.h>#include <net/if.h>#include <net/if_dl.h>#include <net/if_types.h>#include <net/route.h>#include <netinet/in.h>#include <netinet/if_ether.h>#include <arpa/inet.h>#include <err.h>#include <errno.h>#include <netdb.h>#include <nlist.h>#include <paths.h>#include <stdio.h>#include <stdlib.h>#include <strings.h>#include <unistd.h> #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))voidether_print(u_char * cp){ printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]);}voidprint_entry(struct sockaddr_dl * sdl, struct sockaddr_inarp * sin, struct rt_msghdr * rtm){ const char *host; struct hostent *hp; char ifname[IF_NAMESIZE]; hp = 0; host = "?"; printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); if (sdl->sdl_alen) { ether_print((u_char *) LLADDR(sdl)); } else { printf("(incomplete)"); } if (if_indextoname(sdl->sdl_index, ifname) != NULL) { printf(" on %s", ifname); } if (rtm->rtm_rmx.rmx_expire == 0) { printf(" permanent"); } if (sin->sin_other & SIN_PROXY) { printf(" published (proxy only)"); } if (rtm->rtm_addrs & RTA_NETMASK) { sin = (struct sockaddr_inarp *) (ROUNDUP(sdl->sdl_len) + (char *) sdl); if (sin->sin_addr.s_addr == 0xffffffff) { printf(" published"); } if (sin->sin_len != 8) { printf("(weird)"); } } switch (sdl->sdl_type) { case IFT_ETHER: printf(" [ethernet]"); break; case IFT_ISO88025: printf(" [token-ring]"); break; case IFT_L2VLAN: printf(" [vlan]"); break; } printf("/n");}voidsearch(u_long addr, void (*action) (struct sockaddr_dl * sdl, struct sockaddr_inarp * sin, struct rt_msghdr * rtm)){ int mib[6]; size_t needed; char *lim, *buf, *next; struct rt_msghdr *rtm; struct sockaddr_inarp *sin; struct sockaddr_dl *sdl; 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) { errx(1, "route-sysctl-estimate"); } if ((buf = malloc(needed)) == NULL) { errx(1, "malloc"); } if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { errx(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); (char *) sdl = (char *) sin + ROUNDUP(sin->sin_len); if (addr) { if (addr != sin->sin_addr.s_addr) { continue; } } (*action) (sdl, sin, rtm); } free(buf);}intmain(){ search(0, print_entry); return 0;}
