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mirror of https://git.FreeBSD.org/src.git synced 2024-12-05 09:14:03 +00:00
freebsd/lib/libc/net/getifaddrs.c
Bjoern A. Zeeb ca1672da93 Switch getifaddrs(3) to the new API introduced in r231505. Also remove
conditional code parts not used by or applicable to FreeBSD.

The new implementation is supposed to be able to cope with changes to
the 'l' versions of the msghdr structs now used as well as to if_data
allowing future changes without breaking things.

This restores carp(4) config support in HEAD after r231504.

Reviewed by:	glebius, brooks
MFC After:	3 months
2012-02-11 06:05:40 +00:00

344 lines
8.5 KiB
C

/* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 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
*/
/*
* NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform
* try-and-error for region size.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#ifdef NET_RT_IFLIST
#include <sys/param.h>
#include <net/route.h>
#include <sys/sysctl.h>
#include <net/if_dl.h>
#endif
#include <errno.h>
#include <ifaddrs.h>
#include <stdlib.h>
#include <string.h>
#include "un-namespace.h"
#if !defined(AF_LINK)
#define SA_LEN(sa) sizeof(struct sockaddr)
#endif
#if !defined(SA_LEN)
#define SA_LEN(sa) (sa)->sa_len
#endif
#define SALIGN (sizeof(long) - 1)
#define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1))
#ifndef ALIGNBYTES
/*
* On systems with a routing socket, ALIGNBYTES should match the value
* that the kernel uses when building the messages.
*/
#define ALIGNBYTES XXX
#endif
#ifndef ALIGN
#define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
#endif
#define MAX_SYSCTL_TRY 5
int
getifaddrs(struct ifaddrs **pif)
{
int icnt = 1;
int dcnt = 0;
int ncnt = 0;
int ntry = 0;
int mib[6];
size_t needed;
char *buf;
char *next;
struct ifaddrs *cif = 0;
char *p, *p0;
struct rt_msghdr *rtm;
struct if_msghdrl *ifm;
struct ifa_msghdrl *ifam;
struct sockaddr_dl *dl;
struct sockaddr *sa;
struct ifaddrs *ifa, *ift;
struct if_data *if_data;
u_short idx = 0;
int i;
size_t len, alen;
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_IFLISTL;/* extra fields for extensible msghdr structs */
mib[5] = 0; /* no flags */
do {
/*
* We'll try to get addresses several times in case that
* the number of addresses is unexpectedly increased during
* the two sysctl calls. This should rarely happen, but we'll
* try to do our best for applications that assume success of
* this library (which should usually be the case).
* Portability note: since FreeBSD does not add margin of
* memory at the first sysctl, the possibility of failure on
* the second sysctl call is a bit higher.
*/
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) {
if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
free(buf);
return (-1);
}
free(buf);
buf = NULL;
}
} while (buf == NULL);
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_msghdrl *)(void *)rtm;
if (ifm->ifm_addrs & RTA_IFP) {
idx = ifm->ifm_index;
++icnt;
if_data = IF_MSGHDRL_IFM_DATA(ifm);
dcnt += if_data->ifi_datalen;
dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);
dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
ALIGNBYTES;
ncnt += dl->sdl_nlen + 1;
} else
idx = 0;
break;
case RTM_NEWADDR:
ifam = (struct ifa_msghdrl *)(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 *)IFA_MSGHDRL_RTA(ifam);
++icnt;
if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
dcnt += if_data->ifi_datalen + ALIGNBYTES;
/* 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_LEN(sa) == 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_msghdrl *)(void *)rtm;
if ((ifm->ifm_addrs & RTA_IFP) == 0) {
idx = 0;
break;
}
idx = ifm->ifm_index;
dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm);
cif = ift;
ift->ifa_name = names;
ift->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;
ift->ifa_addr = (struct sockaddr *)(void *)data;
memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *)
(void *)dl));
data += SA_RLEN((struct sockaddr *)(void *)dl);
if_data = IF_MSGHDRL_IFM_DATA(ifm);
/* ifm_data needs to be aligned */
ift->ifa_data = data = (void *)ALIGN(data);
memcpy(data, if_data, if_data->ifi_datalen);
data += if_data->ifi_datalen;
ift = (ift->ifa_next = ift + 1);
break;
case RTM_NEWADDR:
ifam = (struct ifa_msghdrl *)(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 *)IFA_MSGHDRL_RTA(ifam);
/* 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;
break;
case RTAX_NETMASK:
ift->ifa_netmask =
(struct sockaddr *)(void *)data;
if (SA_LEN(sa) == 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;
}
if_data = IFA_MSGHDRL_IFAM_DATA(ifam);
/* ifam_data needs to be aligned */
ift->ifa_data = data = (void *)ALIGN(data);
memcpy(data, if_data, if_data->ifi_datalen);
data += if_data->ifi_datalen;
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);
}