lib/libc/net/getifaddrs.c
C | 305 lines | 244 code | 33 blank | 28 comment | 63 complexity | 7b06683bc751cc29f45d23543a7207a6 MD5 | raw file
Possible License(s): MIT, WTFPL, AGPL-1.0, BSD-3-Clause, GPL-3.0, LGPL-2.0, JSON, 0BSD
- /* $NetBSD: getifaddrs.c,v 1.13 2010/11/05 16:23:56 pooka 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 <sys/cdefs.h>
- #if defined(LIBC_SCCS) && !defined(lint)
- __RCSID("$NetBSD: getifaddrs.c,v 1.13 2010/11/05 16:23:56 pooka Exp $");
- #endif /* LIBC_SCCS and not lint */
- #ifndef RUMP_ACTION
- #include "namespace.h"
- #endif
- #include <sys/types.h>
- #include <sys/ioctl.h>
- #include <sys/socket.h>
- #include <net/if.h>
- #include <sys/param.h>
- #include <net/route.h>
- #include <sys/sysctl.h>
- #include <net/if_dl.h>
- #include <assert.h>
- #include <errno.h>
- #include <ifaddrs.h>
- #include <stdlib.h>
- #include <string.h>
- #if defined(__weak_alias) && !defined(RUMP_ACTION)
- __weak_alias(getifaddrs,_getifaddrs)
- __weak_alias(freeifaddrs,_freeifaddrs)
- #endif
- #ifdef RUMP_ACTION
- #include <rump/rump_syscalls.h>
- #define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f)
- #endif
- #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;
- char *p, *p0;
- struct rt_msghdr *rtm;
- struct if_msghdr *ifm;
- struct ifa_msghdr *ifam;
- struct sockaddr *sa;
- struct ifaddrs *ifa, *ift;
- u_short idx = 0;
- int i;
- size_t len, alen;
- char *data;
- char *names;
- _DIAGASSERT(pif != NULL);
- 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, __arraycount(mib), NULL, &needed, NULL, 0) < 0)
- return (-1);
- if ((buf = malloc(needed)) == NULL)
- return (-1);
- if (sysctl(mib, __arraycount(mib), buf, &needed, NULL, 0) < 0) {
- free(buf);
- return (-1);
- }
- for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
- rtm = (struct rt_msghdr *)(void *)next;
- if (rtm->rtm_version != RTM_VERSION)
- continue;
- switch (rtm->rtm_type) {
- case RTM_IFINFO:
- ifm = (struct if_msghdr *)(void *)rtm;
- if (ifm->ifm_addrs & RTA_IFP) {
- const struct sockaddr_dl *dl;
- idx = ifm->ifm_index;
- ++icnt;
- dl = (struct sockaddr_dl *)(void *)(ifm + 1);
- dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl) +
- ALIGNBYTES;
- dcnt += sizeof(ifm->ifm_data);
- ncnt += dl->sdl_nlen + 1;
- } else
- idx = 0;
- break;
- case RTM_NEWADDR:
- ifam = (struct ifa_msghdr *)(void *)rtm;
- if (idx && ifam->ifam_index != idx)
- abort(); /* this cannot happen */
- #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD)
- if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
- break;
- p = (char *)(void *)(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 *)(void *)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 *)(void *)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 *)(void *)data;
- data += sizeof(struct ifaddrs) * icnt;
- names = data + dcnt;
- memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
- ift = ifa;
- idx = 0;
- for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
- rtm = (struct rt_msghdr *)(void *)next;
- if (rtm->rtm_version != RTM_VERSION)
- continue;
- switch (rtm->rtm_type) {
- case RTM_IFINFO:
- ifm = (struct if_msghdr *)(void *)rtm;
- if (ifm->ifm_addrs & RTA_IFP) {
- const struct sockaddr_dl *dl;
- idx = ifm->ifm_index;
- dl = (struct sockaddr_dl *)(void *)(ifm + 1);
- memset(&cif, 0, sizeof(cif));
- cif.ifa_name = names;
- cif.ifa_flags = (int)ifm->ifm_flags;
- memcpy(names, dl->sdl_data,
- (size_t)dl->sdl_nlen);
- names[dl->sdl_nlen] = 0;
- names += dl->sdl_nlen + 1;
- cif.ifa_addr = (struct sockaddr *)(void *)data;
- memcpy(data, dl, (size_t)dl->sdl_len);
- data += SA_RLEN((const struct sockaddr *)(const void *)dl);
- /* ifm_data needs to be aligned */
- cif.ifa_data = data = (void *)ALIGN(data);
- memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
- data += sizeof(ifm->ifm_data);
- } else
- idx = 0;
- break;
- case RTM_NEWADDR:
- ifam = (struct ifa_msghdr *)(void *)rtm;
- if (idx && ifam->ifam_index != idx)
- abort(); /* this cannot happen */
- if (idx == 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 *)(void *)(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 *)(void *)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 *)(void *)p;
- len = SA_RLEN(sa);
- switch (i) {
- case RTAX_IFA:
- ift->ifa_addr =
- (struct sockaddr *)(void *)data;
- memcpy(data, p, len);
- data += len;
- if (ift->ifa_addr->sa_family == AF_LINK)
- ift->ifa_data = cif.ifa_data;
- break;
- case RTAX_NETMASK:
- ift->ifa_netmask =
- (struct sockaddr *)(void *)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 *)(void *)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)
- {
- _DIAGASSERT(ifp != NULL);
- free(ifp);
- }