/* $OpenBSD: getifaddrs.c,v 1.9 2002/08/09 06:12:25 itojun Exp $ */ /* * Copyright (c) 1995, 1999 * Berkeley Software Design, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define SALIGN (sizeof(long) - 1) #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) int getifaddrs(struct ifaddrs **pif) { int icnt = 1; int dcnt = 0; int ncnt = 0; int mib[6]; size_t needed; char *buf; char *next; struct ifaddrs *cif = 0; char *p, *p0; struct rt_msghdr *rtm; struct if_msghdr *ifm; struct ifa_msghdr *ifam; struct sockaddr_dl *dl; struct sockaddr *sa; u_short index = 0; size_t len, alen; struct ifaddrs *ifa, *ift; int i; char *data; char *names; mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; /* protocol */ mib[3] = 0; /* wildcard address family */ mib[4] = NET_RT_IFLIST; mib[5] = 0; /* no flags */ if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) return (-1); if ((buf = malloc(needed)) == NULL) return (-1); if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { free(buf); return (-1); } for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { rtm = (struct rt_msghdr *)next; if (rtm->rtm_version != RTM_VERSION) continue; switch (rtm->rtm_type) { case RTM_IFINFO: ifm = (struct if_msghdr *)rtm; if (ifm->ifm_addrs & RTA_IFP) { index = ifm->ifm_index; ++icnt; dl = (struct sockaddr_dl *)(ifm + 1); dcnt += SA_RLEN((struct sockaddr *)dl) + ALIGNBYTES; dcnt += sizeof(ifm->ifm_data); ncnt += dl->sdl_nlen + 1; } else index = 0; break; case RTM_NEWADDR: ifam = (struct ifa_msghdr *)rtm; if (index && ifam->ifam_index != index) abort(); /* XXX abort illegal in library */ #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) break; p = (char *)(ifam + 1); ++icnt; /* Scan to look for length of address */ alen = 0; for (p0 = p, i = 0; i < RTAX_MAX; i++) { if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) == 0) continue; sa = (struct sockaddr *)p; len = SA_RLEN(sa); if (i == RTAX_IFA) { alen = len; break; } p += len; } for (p = p0, i = 0; i < RTAX_MAX; i++) { if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) == 0) continue; sa = (struct sockaddr *)p; len = SA_RLEN(sa); if (i == RTAX_NETMASK && sa->sa_len == 0) dcnt += alen; else dcnt += len; p += len; } break; } } if (icnt + dcnt + ncnt == 1) { *pif = NULL; free(buf); return (0); } data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); if (data == NULL) { free(buf); return(-1); } ifa = (struct ifaddrs *)data; data += sizeof(struct ifaddrs) * icnt; names = data + dcnt; memset(ifa, 0, sizeof(struct ifaddrs) * icnt); ift = ifa; index = 0; for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { rtm = (struct rt_msghdr *)next; if (rtm->rtm_version != RTM_VERSION) continue; switch (rtm->rtm_type) { case RTM_IFINFO: ifm = (struct if_msghdr *)rtm; if (ifm->ifm_addrs & RTA_IFP) { index = ifm->ifm_index; dl = (struct sockaddr_dl *)(ifm + 1); cif = ift; ift->ifa_name = names; ift->ifa_flags = (int)ifm->ifm_flags; memcpy(names, dl->sdl_data, dl->sdl_nlen); names[dl->sdl_nlen] = 0; names += dl->sdl_nlen + 1; ift->ifa_addr = (struct sockaddr *)data; memcpy(data, dl, ((struct sockaddr *)dl)->sa_len); data += SA_RLEN((struct sockaddr *)dl); /* ifm_data needs to be aligned */ ift->ifa_data = data = (void *)ALIGN(data); memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); data += sizeof(ifm->ifm_data); ift = (ift->ifa_next = ift + 1); } else index = 0; break; case RTM_NEWADDR: ifam = (struct ifa_msghdr *)rtm; if (index && ifam->ifam_index != index) abort(); /* XXX abort illegal in library */ if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) break; ift->ifa_name = cif->ifa_name; ift->ifa_flags = cif->ifa_flags; ift->ifa_data = NULL; p = (char *)(ifam + 1); /* Scan to look for length of address */ alen = 0; for (p0 = p, i = 0; i < RTAX_MAX; i++) { if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) == 0) continue; sa = (struct sockaddr *)p; len = SA_RLEN(sa); if (i == RTAX_IFA) { alen = len; break; } p += len; } for (p = p0, i = 0; i < RTAX_MAX; i++) { if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) == 0) continue; sa = (struct sockaddr *)p; len = SA_RLEN(sa); switch (i) { case RTAX_IFA: ift->ifa_addr = (struct sockaddr *)data; memcpy(data, p, len); data += len; break; case RTAX_NETMASK: ift->ifa_netmask = (struct sockaddr *)data; if (sa->sa_len == 0) { memset(data, 0, alen); data += alen; break; } memcpy(data, p, len); data += len; break; case RTAX_BRD: ift->ifa_broadaddr = (struct sockaddr *)data; memcpy(data, p, len); data += len; break; } p += len; } ift = (ift->ifa_next = ift + 1); break; } } free(buf); if (--ift >= ifa) { ift->ifa_next = NULL; *pif = ifa; } else { *pif = NULL; free(ifa); } return (0); } void freeifaddrs(struct ifaddrs *ifp) { free(ifp); }