HardenedBSD/sbin/ifconfig/af_nd6.c
Bjoern A. Zeeb 21231a7aa6 Update for IETF draft-ietf-6man-ipv6only-flag.
All changes are hidden behind the EXPERIMENTAL option and are not compiled
in by default.

Add ND6_IFF_IPV6_ONLY_MANUAL to be able to set the interface into no-IPv4-mode
manually without router advertisement options.  This will allow developers to
test software for the appropriate behaviour even on dual-stack networks or
IPv6-Only networks without the option being set in RA messages.
Update ifconfig to allow setting and displaying the flag.

Update the checks for the filters to check for either the automatic or the manual
flag to be set.  Add REVARP to the list of filtered IPv4-related protocols and add
an input filter similar to the output filter.

Add a check, when receiving the IPv6-Only RA flag to see if the receiving
interface has any IPv4 configured.  If it does, ignore the IPv6-Only flag.

Add a per-VNET global sysctl, which is on by default, to not process the automatic
RA IPv6-Only flag.  This way an administrator (if this is compiled in) has control
over the behaviour in case the node still relies on IPv4.
2019-03-06 23:31:42 +00:00

179 lines
4.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009 Hiroki Sato. 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.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/route.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ifaddrs.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netinet6/nd6.h>
#include "ifconfig.h"
#define MAX_SYSCTL_TRY 5
#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
#define ND6BITS "\020\001PERFORMNUD\002ACCEPT_RTADV\003PREFER_SOURCE" \
"\004IFDISABLED\005DONT_SET_IFROUTE\006AUTO_LINKLOCAL" \
"\007NO_RADR\010NO_PREFER_IFACE\011NO_DAD" \
"\012IPV6_ONLY\013IPV6_ONLY_MANUAL" \
"\020DEFAULTIF"
#else
#define ND6BITS "\020\001PERFORMNUD\002ACCEPT_RTADV\003PREFER_SOURCE" \
"\004IFDISABLED\005DONT_SET_IFROUTE\006AUTO_LINKLOCAL" \
"\007NO_RADR\010NO_PREFER_IFACE\011NO_DAD\020DEFAULTIF"
#endif
static int isnd6defif(int);
void setnd6flags(const char *, int, int, const struct afswtch *);
void setnd6defif(const char *, int, int, const struct afswtch *);
void nd6_status(int);
void
setnd6flags(const char *dummyaddr __unused,
int d, int s,
const struct afswtch *afp)
{
struct in6_ndireq nd;
int error;
memset(&nd, 0, sizeof(nd));
strlcpy(nd.ifname, ifr.ifr_name, sizeof(nd.ifname));
error = ioctl(s, SIOCGIFINFO_IN6, &nd);
if (error) {
warn("ioctl(SIOCGIFINFO_IN6)");
return;
}
if (d < 0)
nd.ndi.flags &= ~(-d);
else
nd.ndi.flags |= d;
error = ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd);
if (error)
warn("ioctl(SIOCSIFINFO_IN6)");
}
void
setnd6defif(const char *dummyaddr __unused,
int d, int s,
const struct afswtch *afp)
{
struct in6_ndifreq ndifreq;
int ifindex;
int error;
memset(&ndifreq, 0, sizeof(ndifreq));
strlcpy(ndifreq.ifname, ifr.ifr_name, sizeof(ndifreq.ifname));
if (d < 0) {
if (isnd6defif(s)) {
/* ifindex = 0 means to remove default if */
ifindex = 0;
} else
return;
} else if ((ifindex = if_nametoindex(ndifreq.ifname)) == 0) {
warn("if_nametoindex(%s)", ndifreq.ifname);
return;
}
ndifreq.ifindex = ifindex;
error = ioctl(s, SIOCSDEFIFACE_IN6, (caddr_t)&ndifreq);
if (error)
warn("ioctl(SIOCSDEFIFACE_IN6)");
}
static int
isnd6defif(int s)
{
struct in6_ndifreq ndifreq;
unsigned int ifindex;
int error;
memset(&ndifreq, 0, sizeof(ndifreq));
strlcpy(ndifreq.ifname, ifr.ifr_name, sizeof(ndifreq.ifname));
ifindex = if_nametoindex(ndifreq.ifname);
error = ioctl(s, SIOCGDEFIFACE_IN6, (caddr_t)&ndifreq);
if (error) {
warn("ioctl(SIOCGDEFIFACE_IN6)");
return (error);
}
return (ndifreq.ifindex == ifindex);
}
void
nd6_status(int s)
{
struct in6_ndireq nd;
int s6;
int error;
int isdefif;
memset(&nd, 0, sizeof(nd));
strlcpy(nd.ifname, ifr.ifr_name, sizeof(nd.ifname));
if ((s6 = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
if (errno != EAFNOSUPPORT && errno != EPROTONOSUPPORT)
warn("socket(AF_INET6, SOCK_DGRAM)");
return;
}
error = ioctl(s6, SIOCGIFINFO_IN6, &nd);
if (error) {
if (errno != EPFNOSUPPORT)
warn("ioctl(SIOCGIFINFO_IN6)");
close(s6);
return;
}
isdefif = isnd6defif(s6);
close(s6);
if (nd.ndi.flags == 0 && !isdefif)
return;
printb("\tnd6 options",
(unsigned int)(nd.ndi.flags | (isdefif << 15)), ND6BITS);
putchar('\n');
}