int arp_EtherAddr(struct in_addr ipaddr, struct sockaddr_dl *hwaddr, int verbose) { int mib[6], skip; size_t needed; char *buf, *ptr, *end; struct if_msghdr *ifm; struct ifa_msghdr *ifam; struct sockaddr_dl *dl; struct sockaddr *sa[RTAX_MAX]; mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = 0; mib[4] = NET_RT_IFLIST; mib[5] = 0; if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n", strerror(errno)); return 0; } if ((buf = malloc(needed)) == NULL) return 0; if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { free(buf); return 0; } end = buf + needed; ptr = buf; while (ptr < end) { ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ if (ifm->ifm_type != RTM_IFINFO) break; dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); ptr += ifm->ifm_msglen; /* First ifa_msghdr */ while (ptr < end) { ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ break; ptr += ifam->ifam_msglen; if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != (RTA_NETMASK|RTA_IFA)) continue; /* Found a candidate. Do the addresses match ? */ if (log_IsKept(LogDEBUG) && ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", dl->sdl_nlen, dl->sdl_data); iface_ParseHdr(ifam, sa); if (sa[RTAX_IFA]->sa_family == AF_INET) { struct sockaddr_in *ifa, *netmask; ifa = (struct sockaddr_in *)sa[RTAX_IFA]; netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; if (log_IsKept(LogDEBUG)) { char a[16]; strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); a[sizeof a - 1] = '\0'; log_Printf(LogDEBUG, "Check addr %s, mask %s\n", inet_ntoa(ifa->sin_addr), a); } if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == (ipaddr.s_addr & netmask->sin_addr.s_addr)) { log_Printf(verbose ? LogPHASE : LogDEBUG, "Found interface %.*s for %s\n", dl->sdl_nlen, dl->sdl_data, inet_ntoa(ipaddr)); memcpy(hwaddr, dl, dl->sdl_len); free(buf); return 1; } } } } free(buf); return 0; }
struct iface * iface_Create(const char *name) { int mib[6], maxtries, err; size_t needed, namelen; char *buf, *ptr, *end; struct if_msghdr *ifm; struct ifa_msghdr *ifam; struct sockaddr_dl *dl; struct sockaddr *sa[RTAX_MAX]; struct iface *iface; struct iface_addr *addr; mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = 0; mib[4] = NET_RT_IFLIST; mib[5] = 0; maxtries = 20; err = 0; do { if (maxtries-- == 0 || (err && err != ENOMEM)) { fprintf(stderr, "iface_Create: sysctl: %s\n", strerror(err)); return NULL; } if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { fprintf(stderr, "iface_Create: sysctl: estimate: %s\n", strerror(errno)); return NULL; } if ((buf = (char *)malloc(needed)) == NULL) { fprintf(stderr, "iface_Create: malloc failed: %s\n", strerror(errno)); return NULL; } if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { err = errno; free(buf); buf = NULL; } } while (buf == NULL); ptr = buf; end = buf + needed; iface = NULL; namelen = strlen(name); while (ptr < end && iface == NULL) { ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ if (ifm->ifm_type != RTM_IFINFO) break; dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ if (dl->sdl_nlen == namelen && !strncmp(name, dl->sdl_data, namelen)) { iface = (struct iface *)malloc(sizeof *iface); if (iface == NULL) { fprintf(stderr, "iface_Create: malloc: %s\n", strerror(errno)); return NULL; } iface->name = strdup(name); iface->descr = NULL; iface->index = ifm->ifm_index; iface->flags = ifm->ifm_flags; iface->mtu = 0; iface->addrs = 0; iface->addr = NULL; } ptr += ifm->ifm_msglen; /* First ifa_msghdr */ for (; ptr < end; ptr += ifam->ifam_msglen) { ifam = (struct ifa_msghdr *)ptr; /* Next if address */ if (ifam->ifam_type != RTM_NEWADDR) /* finished this if */ break; if (iface != NULL && ifam->ifam_addrs & RTA_IFA) { /* Found a configured interface ! */ iface_ParseHdr(ifam, sa); if (sa[RTAX_IFA] && (sa[RTAX_IFA]->sa_family == AF_INET #ifndef NOINET6 || sa[RTAX_IFA]->sa_family == AF_INET6 #endif )) { /* Record the address */ addr = (struct iface_addr *) realloc(iface->addr, (iface->addrs + 1) * sizeof iface->addr[0]); if (addr == NULL) break; iface->addr = addr; addr += iface->addrs; iface->addrs++; ncprange_setsa(&addr->ifa, sa[RTAX_IFA], sa[RTAX_NETMASK]); if (sa[RTAX_BRD]) ncpaddr_setsa(&addr->peer, sa[RTAX_BRD]); else ncpaddr_init(&addr->peer); } } } } free(buf); return iface; }