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mirror of https://git.FreeBSD.org/src.git synced 2024-12-23 11:18:54 +00:00
freebsd/lib/libc/net/getifaddrs.c
Hajimu UMEMOTO 2cbe834ad1 sysctl(NET_RT_IFLIST) up to several (currently 5) times.
This will make the behavior robuster if many addresses are added
after the size estimation of storage at the first sysctl.

Reviewed by:	JINMEI Tatuya <jinmei@isl.rdc.toshiba.co.jp>
MFC after:	1 week
2002-07-25 08:08:30 +00:00

419 lines
10 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
#if _BSDI_VERSION >= 199701
#define HAVE_IFM_DATA
#endif
#if _BSDI_VERSION >= 199802
/* ifam_data is very specific to recent versions of bsdi */
#define HAVE_IFAM_DATA
#endif
#if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__)
#define HAVE_IFM_DATA
#endif
#define MAX_SYSCTL_TRY 5
int
getifaddrs(struct ifaddrs **pif)
{
int icnt = 1;
int dcnt = 0;
int ncnt = 0;
#ifdef NET_RT_IFLIST
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_msghdr *ifm;
struct ifa_msghdr *ifam;
struct sockaddr_dl *dl;
struct sockaddr *sa;
struct ifaddrs *ifa, *ift;
u_short idx = 0;
#else /* NET_RT_IFLIST */
char buf[1024];
int m, sock;
struct ifconf ifc;
struct ifreq *ifr;
struct ifreq *lifr;
#endif /* NET_RT_IFLIST */
int i;
size_t len, alen;
char *data;
char *names;
#ifdef NET_RT_IFLIST
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 */
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_msghdr *)(void *)rtm;
if (ifm->ifm_addrs & RTA_IFP) {
idx = ifm->ifm_index;
++icnt;
dl = (struct sockaddr_dl *)(void *)(ifm + 1);
dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
ALIGNBYTES;
#ifdef HAVE_IFM_DATA
dcnt += sizeof(ifm->ifm_data);
#endif /* HAVE_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;
#ifdef HAVE_IFAM_DATA
dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES;
#endif /* HAVE_IFAM_DATA */
/* 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;
}
}
#else /* NET_RT_IFLIST */
ifc.ifc_buf = buf;
ifc.ifc_len = sizeof(buf);
if ((sock = _socket(AF_INET, SOCK_STREAM, 0)) < 0)
return (-1);
i = _ioctl(sock, SIOCGIFCONF, (char *)&ifc);
_close(sock);
if (i < 0)
return (-1);
ifr = ifc.ifc_req;
lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
while (ifr < lifr) {
struct sockaddr *sa;
sa = &ifr->ifr_addr;
++icnt;
dcnt += SA_RLEN(sa);
ncnt += sizeof(ifr->ifr_name) + 1;
if (SA_LEN(sa) < sizeof(*sa))
ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa));
else
ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
}
#endif /* NET_RT_IFLIST */
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;
#ifdef NET_RT_IFLIST
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) {
idx = ifm->ifm_index;
dl = (struct sockaddr_dl *)(void *)(ifm + 1);
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);
#ifdef HAVE_IFM_DATA
/* 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);
#else /* HAVE_IFM_DATA */
ift->ifa_data = NULL;
#endif /* HAVE_IFM_DATA */
ift = (ift->ifa_next = ift + 1);
} 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;
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;
}
#ifdef HAVE_IFAM_DATA
/* ifam_data needs to be aligned */
ift->ifa_data = data = (void *)ALIGN(data);
memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data));
data += sizeof(ifam->ifam_data);
#endif /* HAVE_IFAM_DATA */
ift = (ift->ifa_next = ift + 1);
break;
}
}
free(buf);
#else /* NET_RT_IFLIST */
ifr = ifc.ifc_req;
lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
while (ifr < lifr) {
struct sockaddr *sa;
ift->ifa_name = names;
names[sizeof(ifr->ifr_name)] = 0;
strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name));
while (*names++)
;
ift->ifa_addr = (struct sockaddr *)data;
sa = &ifr->ifr_addr;
memcpy(data, sa, SA_LEN(sa));
data += SA_RLEN(sa);
ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
ift = (ift->ifa_next = ift + 1);
}
#endif /* NET_RT_IFLIST */
if (--ift >= ifa) {
ift->ifa_next = NULL;
*pif = ifa;
} else {
*pif = NULL;
free(ifa);
}
return (0);
}
void
freeifaddrs(struct ifaddrs *ifp)
{
free(ifp);
}