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freebsd-skq/sys/netinet6/nd6_nbr.c
kan c8da6fae2c Do pass removing some write-only variables from the kernel. 
This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385
2017-12-25 04:48:39 +00:00

1548 lines
42 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*
* $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <sys/callout.h>
#include <sys/refcount.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/if_var.h>
#include <net/route.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <net/if_llatbl.h>
#include <netinet6/in6_var.h>
#include <netinet6/in6_ifattach.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#include <netinet/ip_carp.h>
#include <netinet6/send.h>
#define SDL(s) ((struct sockaddr_dl *)s)
struct dadq;
static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
static void nd6_dad_add(struct dadq *dp);
static void nd6_dad_del(struct dadq *dp);
static void nd6_dad_rele(struct dadq *);
static void nd6_dad_starttimer(struct dadq *, int, int);
static void nd6_dad_stoptimer(struct dadq *);
static void nd6_dad_timer(struct dadq *);
static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
static void nd6_dad_ns_output(struct dadq *);
static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
static void nd6_dad_na_input(struct ifaddr *);
static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
static VNET_DEFINE(int, dad_enhanced) = 1;
#define V_dad_enhanced VNET(dad_enhanced)
SYSCTL_DECL(_net_inet6_ip6);
SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(dad_enhanced), 0,
"Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to
transmit DAD packet */
#define V_dad_maxtry VNET(dad_maxtry)
/*
* Input a Neighbor Solicitation Message.
*
* Based on RFC 2461
* Based on RFC 2462 (duplicate address detection)
*/
void
nd6_ns_input(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_neighbor_solicit *nd_ns;
struct in6_addr saddr6 = ip6->ip6_src;
struct in6_addr daddr6 = ip6->ip6_dst;
struct in6_addr taddr6;
struct in6_addr myaddr6;
char *lladdr = NULL;
struct ifaddr *ifa = NULL;
int lladdrlen = 0;
int anycast = 0, proxy = 0, tentative = 0;
int tlladdr;
int rflag;
union nd_opts ndopts;
struct sockaddr_dl proxydl;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
rflag = 0;
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
if (nd_ns == NULL) {
ICMP6STAT_INC(icp6s_tooshort);
return;
}
#endif
ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
taddr6 = nd_ns->nd_ns_target;
if (in6_setscope(&taddr6, ifp, NULL) != 0)
goto bad;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
goto bad;
}
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
/* dst has to be a solicited node multicast address. */
if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
/* don't check ifindex portion */
daddr6.s6_addr32[1] == 0 &&
daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
daddr6.s6_addr8[12] == 0xff) {
; /* good */
} else {
nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
"(wrong ip6 dst)\n"));
goto bad;
}
} else if (!V_nd6_onlink_ns_rfc4861) {
struct sockaddr_in6 src_sa6;
/*
* According to recent IETF discussions, it is not a good idea
* to accept a NS from an address which would not be deemed
* to be a neighbor otherwise. This point is expected to be
* clarified in future revisions of the specification.
*/
bzero(&src_sa6, sizeof(src_sa6));
src_sa6.sin6_family = AF_INET6;
src_sa6.sin6_len = sizeof(src_sa6);
src_sa6.sin6_addr = saddr6;
if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
nd6log((LOG_INFO, "nd6_ns_input: "
"NS packet from non-neighbor\n"));
goto bad;
}
}
if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
goto bad;
}
icmp6len -= sizeof(*nd_ns);
nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_ns_input: invalid ND option, ignored\n"));
/* nd6_options have incremented stats */
goto freeit;
}
if (ndopts.nd_opts_src_lladdr) {
lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
}
if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
"(link-layer address option)\n"));
goto bad;
}
/*
* Attaching target link-layer address to the NA?
* (RFC 2461 7.2.4)
*
* NS IP dst is unicast/anycast MUST NOT add
* NS IP dst is solicited-node multicast MUST add
*
* In implementation, we add target link-layer address by default.
* We do not add one in MUST NOT cases.
*/
if (!IN6_IS_ADDR_MULTICAST(&daddr6))
tlladdr = 0;
else
tlladdr = 1;
/*
* Target address (taddr6) must be either:
* (1) Valid unicast/anycast address for my receiving interface,
* (2) Unicast address for which I'm offering proxy service, or
* (3) "tentative" address on which DAD is being performed.
*/
/* (1) and (3) check. */
if (ifp->if_carp)
ifa = (*carp_iamatch6_p)(ifp, &taddr6);
else
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
/* (2) check. */
if (ifa == NULL) {
struct sockaddr_dl rt_gateway;
struct rt_addrinfo info;
struct sockaddr_in6 dst6;
bzero(&dst6, sizeof(dst6));
dst6.sin6_len = sizeof(struct sockaddr_in6);
dst6.sin6_family = AF_INET6;
dst6.sin6_addr = taddr6;
bzero(&rt_gateway, sizeof(rt_gateway));
rt_gateway.sdl_len = sizeof(rt_gateway);
bzero(&info, sizeof(info));
info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6,
0, 0, &info) == 0) {
if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
rt_gateway.sdl_family == AF_LINK) {
/*
* proxy NDP for single entry
*/
proxydl = *SDL(&rt_gateway);
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(
ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
if (ifa)
proxy = 1;
}
}
}
if (ifa == NULL) {
/*
* We've got an NS packet, and we don't have that adddress
* assigned for us. We MUST silently ignore it.
* See RFC2461 7.2.3.
*/
goto freeit;
}
myaddr6 = *IFA_IN6(ifa);
anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
goto freeit;
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
"(if %d, NS packet %d)\n",
ip6_sprintf(ip6bufs, &taddr6),
ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
ip6_sprintf(ip6bufs, &saddr6)));
goto freeit;
}
/*
* We have neighbor solicitation packet, with target address equals to
* one of my tentative address.
*
* src addr how to process?
* --- ---
* multicast of course, invalid (rejected in ip6_input)
* unicast somebody is doing address resolution -> ignore
* unspec dup address detection
*
* The processing is defined in RFC 2462.
*/
if (tentative) {
/*
* If source address is unspecified address, it is for
* duplicate address detection.
*
* If not, the packet is for addess resolution;
* silently ignore it.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
goto freeit;
}
/*
* If the source address is unspecified address, entries must not
* be created or updated.
* It looks that sender is performing DAD. Output NA toward
* all-node multicast address, to tell the sender that I'm using
* the address.
* S bit ("solicited") must be zero.
*/
if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
struct in6_addr in6_all;
in6_all = in6addr_linklocal_allnodes;
if (in6_setscope(&in6_all, ifp, NULL) != 0)
goto bad;
nd6_na_output_fib(ifp, &in6_all, &taddr6,
((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
M_GETFIB(m));
goto freeit;
}
nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
ND_NEIGHBOR_SOLICIT, 0);
nd6_na_output_fib(ifp, &saddr6, &taddr6,
((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
rflag | ND_NA_FLAG_SOLICITED, tlladdr,
proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
freeit:
if (ifa != NULL)
ifa_free(ifa);
m_freem(m);
return;
bad:
nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
ip6_sprintf(ip6bufs, &saddr6)));
nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
ip6_sprintf(ip6bufs, &daddr6)));
nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
ip6_sprintf(ip6bufs, &taddr6)));
ICMP6STAT_INC(icp6s_badns);
if (ifa != NULL)
ifa_free(ifa);
m_freem(m);
}
/*
* Output a Neighbor Solicitation Message. Caller specifies:
* - ICMP6 header source IP6 address
* - ND6 header target IP6 address
* - ND6 header source datalink address
*
* Based on RFC 2461
* Based on RFC 2462 (duplicate address detection)
*
* ln - for source address determination
* nonce - If non-NULL, NS is used for duplicate address detection and
* the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
*/
static void
nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
const struct in6_addr *daddr6, const struct in6_addr *taddr6,
uint8_t *nonce, u_int fibnum)
{
struct mbuf *m;
struct m_tag *mtag;
struct ip6_hdr *ip6;
struct nd_neighbor_solicit *nd_ns;
struct ip6_moptions im6o;
int icmp6len;
int maxlen;
caddr_t mac;
if (IN6_IS_ADDR_MULTICAST(taddr6))
return;
/* estimate the size of message */
maxlen = sizeof(*ip6) + sizeof(*nd_ns);
maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
"%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
__func__, max_linkhdr, maxlen, MCLBYTES));
if (max_linkhdr + maxlen > MHLEN)
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
else
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL)
return;
M_SETFIB(m, fibnum);
if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 255;
im6o.im6o_multicast_loop = 0;
}
icmp6len = sizeof(*nd_ns);
m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
/* fill neighbor solicitation packet */
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
/* ip6->ip6_plen will be set later */
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 255;
if (daddr6)
ip6->ip6_dst = *daddr6;
else {
ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
ip6->ip6_dst.s6_addr16[1] = 0;
ip6->ip6_dst.s6_addr32[1] = 0;
ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
ip6->ip6_dst.s6_addr8[12] = 0xff;
if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
goto bad;
}
if (nonce == NULL) {
struct ifaddr *ifa = NULL;
/*
* RFC2461 7.2.2:
* "If the source address of the packet prompting the
* solicitation is the same as one of the addresses assigned
* to the outgoing interface, that address SHOULD be placed
* in the IP Source Address of the outgoing solicitation.
* Otherwise, any one of the addresses assigned to the
* interface should be used."
*
* We use the source address for the prompting packet
* (saddr6), if saddr6 belongs to the outgoing interface.
* Otherwise, we perform the source address selection as usual.
*/
if (saddr6 != NULL)
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
if (ifa != NULL) {
/* ip6_src set already. */
ip6->ip6_src = *saddr6;
ifa_free(ifa);
} else {
int error;
struct in6_addr dst6, src6;
uint32_t scopeid;
in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
error = in6_selectsrc_addr(fibnum, &dst6,
scopeid, ifp, &src6, NULL);
if (error) {
char ip6buf[INET6_ADDRSTRLEN];
nd6log((LOG_DEBUG, "%s: source can't be "
"determined: dst=%s, error=%d\n", __func__,
ip6_sprintf(ip6buf, &dst6),
error));
goto bad;
}
ip6->ip6_src = src6;
}
} else {
/*
* Source address for DAD packet must always be IPv6
* unspecified address. (0::0)
* We actually don't have to 0-clear the address (we did it
* above), but we do so here explicitly to make the intention
* clearer.
*/
bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
}
nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
nd_ns->nd_ns_code = 0;
nd_ns->nd_ns_reserved = 0;
nd_ns->nd_ns_target = *taddr6;
in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
/*
* Add source link-layer address option.
*
* spec implementation
* --- ---
* DAD packet MUST NOT do not add the option
* there's no link layer address:
* impossible do not add the option
* there's link layer address:
* Multicast NS MUST add one add the option
* Unicast NS SHOULD add one add the option
*/
if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
/* 8 byte alignments... */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
bzero((caddr_t)nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
}
/*
* Add a Nonce option (RFC 3971) to detect looped back NS messages.
* This behavior is documented as Enhanced Duplicate Address
* Detection in RFC 7527.
* net.inet6.ip6.dad_enhanced=0 disables this.
*/
if (V_dad_enhanced != 0 && nonce != NULL) {
int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
/* 8-byte alignment is required. */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
bzero((caddr_t)nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_NONCE;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
}
ip6->ip6_plen = htons((u_short)icmp6len);
nd_ns->nd_ns_cksum = 0;
nd_ns->nd_ns_cksum =
in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
if (send_sendso_input_hook != NULL) {
mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
sizeof(unsigned short), M_NOWAIT);
if (mtag == NULL)
goto bad;
*(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
m_tag_prepend(m, mtag);
}
ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
&im6o, NULL, NULL);
icmp6_ifstat_inc(ifp, ifs6_out_msg);
icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
return;
bad:
m_freem(m);
}
#ifndef BURN_BRIDGES
void
nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
{
nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
}
#endif
/*
* Neighbor advertisement input handling.
*
* Based on RFC 2461
* Based on RFC 2462 (duplicate address detection)
*
* the following items are not implemented yet:
* - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
* - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
*/
void
nd6_na_input(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp = m->m_pkthdr.rcvif;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
struct nd_neighbor_advert *nd_na;
struct in6_addr daddr6 = ip6->ip6_dst;
struct in6_addr taddr6;
int flags;
int is_router;
int is_solicited;
int is_override;
char *lladdr = NULL;
int lladdrlen = 0;
int checklink = 0;
struct ifaddr *ifa;
struct llentry *ln = NULL;
union nd_opts ndopts;
struct mbuf *chain = NULL;
struct sockaddr_in6 sin6;
u_char linkhdr[LLE_MAX_LINKHDR];
size_t linkhdrsize;
int lladdr_off;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
if (ip6->ip6_hlim != 255) {
nd6log((LOG_ERR,
"nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
goto bad;
}
#ifndef PULLDOWN_TEST
IP6_EXTHDR_CHECK(m, off, icmp6len,);
nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
#else
IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
if (nd_na == NULL) {
ICMP6STAT_INC(icp6s_tooshort);
return;
}
#endif
flags = nd_na->nd_na_flags_reserved;
is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
memset(&sin6, 0, sizeof(sin6));
taddr6 = nd_na->nd_na_target;
if (in6_setscope(&taddr6, ifp, NULL))
goto bad; /* XXX: impossible */
if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
nd6log((LOG_ERR,
"nd6_na_input: invalid target address %s\n",
ip6_sprintf(ip6bufs, &taddr6)));
goto bad;
}
if (IN6_IS_ADDR_MULTICAST(&daddr6))
if (is_solicited) {
nd6log((LOG_ERR,
"nd6_na_input: a solicited adv is multicasted\n"));
goto bad;
}
icmp6len -= sizeof(*nd_na);
nd6_option_init(nd_na + 1, icmp6len, &ndopts);
if (nd6_options(&ndopts) < 0) {
nd6log((LOG_INFO,
"nd6_na_input: invalid ND option, ignored\n"));
/* nd6_options have incremented stats */
goto freeit;
}
if (ndopts.nd_opts_tgt_lladdr) {
lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
}
/*
* This effectively disables the DAD check on a non-master CARP
* address.
*/
if (ifp->if_carp)
ifa = (*carp_iamatch6_p)(ifp, &taddr6);
else
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
/*
* Target address matches one of my interface address.
*
* If my address is tentative, this means that there's somebody
* already using the same address as mine. This indicates DAD failure.
* This is defined in RFC 2462.
*
* Otherwise, process as defined in RFC 2461.
*/
if (ifa
&& (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
nd6_dad_na_input(ifa);
ifa_free(ifa);
goto freeit;
}
/* Just for safety, maybe unnecessary. */
if (ifa) {
ifa_free(ifa);
log(LOG_ERR,
"nd6_na_input: duplicate IP6 address %s\n",
ip6_sprintf(ip6bufs, &taddr6));
goto freeit;
}
if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
"(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
ifp->if_addrlen, lladdrlen - 2));
goto bad;
}
/*
* If no neighbor cache entry is found, NA SHOULD silently be
* discarded.
*/
IF_AFDATA_RLOCK(ifp);
ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
IF_AFDATA_RUNLOCK(ifp);
if (ln == NULL) {
goto freeit;
}
if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
/*
* If the link-layer has address, and no lladdr option came,
* discard the packet.
*/
if (ifp->if_addrlen && lladdr == NULL) {
goto freeit;
}
/*
* Record link-layer address, and update the state.
*/
linkhdrsize = sizeof(linkhdr);
if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
linkhdr, &linkhdrsize, &lladdr_off) != 0)
return;
if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
lladdr_off) == 0) {
ln = NULL;
goto freeit;
}
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
if (is_solicited)
nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
else
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
if ((ln->ln_router = is_router) != 0) {
/*
* This means a router's state has changed from
* non-reachable to probably reachable, and might
* affect the status of associated prefixes..
*/
checklink = 1;
}
} else {
int llchange;
/*
* Check if the link-layer address has changed or not.
*/
if (lladdr == NULL)
llchange = 0;
else {
if (ln->la_flags & LLE_VALID) {
if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
llchange = 1;
else
llchange = 0;
} else
llchange = 1;
}
/*
* This is VERY complex. Look at it with care.
*
* override solicit lladdr llchange action
* (L: record lladdr)
*
* 0 0 n -- (2c)
* 0 0 y n (2b) L
* 0 0 y y (1) REACHABLE->STALE
* 0 1 n -- (2c) *->REACHABLE
* 0 1 y n (2b) L *->REACHABLE
* 0 1 y y (1) REACHABLE->STALE
* 1 0 n -- (2a)
* 1 0 y n (2a) L
* 1 0 y y (2a) L *->STALE
* 1 1 n -- (2a) *->REACHABLE
* 1 1 y n (2a) L *->REACHABLE
* 1 1 y y (2a) L *->REACHABLE
*/
if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
/*
* If state is REACHABLE, make it STALE.
* no other updates should be done.
*/
if (ln->ln_state == ND6_LLINFO_REACHABLE)
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
goto freeit;
} else if (is_override /* (2a) */
|| (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
|| lladdr == NULL) { /* (2c) */
/*
* Update link-local address, if any.
*/
if (lladdr != NULL) {
linkhdrsize = sizeof(linkhdr);
if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
linkhdr, &linkhdrsize, &lladdr_off) != 0)
goto freeit;
if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
linkhdrsize, lladdr_off) == 0) {
ln = NULL;
goto freeit;
}
EVENTHANDLER_INVOKE(lle_event, ln,
LLENTRY_RESOLVED);
}
/*
* If solicited, make the state REACHABLE.
* If not solicited and the link-layer address was
* changed, make it STALE.
*/
if (is_solicited)
nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
else {
if (lladdr != NULL && llchange)
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
}
}
if (ln->ln_router && !is_router) {
/*
* The peer dropped the router flag.
* Remove the sender from the Default Router List and
* update the Destination Cache entries.
*/
struct ifnet *nd6_ifp;
nd6_ifp = lltable_get_ifp(ln->lle_tbl);
if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
(ND_IFINFO(nd6_ifp)->flags &
ND6_IFF_ACCEPT_RTADV) != 0)
/*
* Even if the neighbor is not in the default
* router list, the neighbor may be used as a
* next hop for some destinations (e.g. redirect
* case). So we must call rt6_flush explicitly.
*/
rt6_flush(&ip6->ip6_src, ifp);
}
ln->ln_router = is_router;
}
/* XXX - QL
* Does this matter?
* rt->rt_flags &= ~RTF_REJECT;
*/
ln->la_asked = 0;
if (ln->la_hold != NULL)
nd6_grab_holdchain(ln, &chain, &sin6);
freeit:
if (ln != NULL)
LLE_WUNLOCK(ln);
if (chain != NULL)
nd6_flush_holdchain(ifp, chain, &sin6);
if (checklink)
pfxlist_onlink_check();
m_freem(m);
return;
bad:
if (ln != NULL)
LLE_WUNLOCK(ln);
ICMP6STAT_INC(icp6s_badna);
m_freem(m);
}
/*
* Neighbor advertisement output handling.
*
* Based on RFC 2461
*
* the following items are not implemented yet:
* - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
* - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
*
* tlladdr - 1 if include target link-layer address
* sdl0 - sockaddr_dl (= proxy NA) or NULL
*/
static void
nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
const struct in6_addr *taddr6, u_long flags, int tlladdr,
struct sockaddr *sdl0, u_int fibnum)
{
struct mbuf *m;
struct m_tag *mtag;
struct ip6_hdr *ip6;
struct nd_neighbor_advert *nd_na;
struct ip6_moptions im6o;
struct in6_addr daddr6, dst6, src6;
uint32_t scopeid;
int icmp6len, maxlen, error;
caddr_t mac = NULL;
daddr6 = *daddr6_0; /* make a local copy for modification */
/* estimate the size of message */
maxlen = sizeof(*ip6) + sizeof(*nd_na);
maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
"%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
__func__, max_linkhdr, maxlen, MCLBYTES));
if (max_linkhdr + maxlen > MHLEN)
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
else
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL)
return;
M_SETFIB(m, fibnum);
if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
m->m_flags |= M_MCAST;
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 255;
im6o.im6o_multicast_loop = 0;
}
icmp6len = sizeof(*nd_na);
m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
/* fill neighbor advertisement packet */
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_flow = 0;
ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_nxt = IPPROTO_ICMPV6;
ip6->ip6_hlim = 255;
if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
/* reply to DAD */
daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
daddr6.s6_addr16[1] = 0;
daddr6.s6_addr32[1] = 0;
daddr6.s6_addr32[2] = 0;
daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
if (in6_setscope(&daddr6, ifp, NULL))
goto bad;
flags &= ~ND_NA_FLAG_SOLICITED;
}
ip6->ip6_dst = daddr6;
/*
* Select a source whose scope is the same as that of the dest.
*/
in6_splitscope(&daddr6, &dst6, &scopeid);
error = in6_selectsrc_addr(fibnum, &dst6,
scopeid, ifp, &src6, NULL);
if (error) {
char ip6buf[INET6_ADDRSTRLEN];
nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
"determined: dst=%s, error=%d\n",
ip6_sprintf(ip6buf, &daddr6), error));
goto bad;
}
ip6->ip6_src = src6;
nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
nd_na->nd_na_code = 0;
nd_na->nd_na_target = *taddr6;
in6_clearscope(&nd_na->nd_na_target); /* XXX */
/*
* "tlladdr" indicates NS's condition for adding tlladdr or not.
* see nd6_ns_input() for details.
* Basically, if NS packet is sent to unicast/anycast addr,
* target lladdr option SHOULD NOT be included.
*/
if (tlladdr) {
/*
* sdl0 != NULL indicates proxy NA. If we do proxy, use
* lladdr in sdl0. If we are not proxying (sending NA for
* my address) use lladdr configured for the interface.
*/
if (sdl0 == NULL) {
if (ifp->if_carp)
mac = (*carp_macmatch6_p)(ifp, m, taddr6);
if (mac == NULL)
mac = nd6_ifptomac(ifp);
} else if (sdl0->sa_family == AF_LINK) {
struct sockaddr_dl *sdl;
sdl = (struct sockaddr_dl *)sdl0;
if (sdl->sdl_alen == ifp->if_addrlen)
mac = LLADDR(sdl);
}
}
if (tlladdr && mac) {
int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
/* roundup to 8 bytes alignment! */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
bzero((caddr_t)nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
} else
flags &= ~ND_NA_FLAG_OVERRIDE;
ip6->ip6_plen = htons((u_short)icmp6len);
nd_na->nd_na_flags_reserved = flags;
nd_na->nd_na_cksum = 0;
nd_na->nd_na_cksum =
in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
if (send_sendso_input_hook != NULL) {
mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
sizeof(unsigned short), M_NOWAIT);
if (mtag == NULL)
goto bad;
*(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
m_tag_prepend(m, mtag);
}
ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
icmp6_ifstat_inc(ifp, ifs6_out_msg);
icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
return;
bad:
m_freem(m);
}
#ifndef BURN_BRIDGES
void
nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
const struct in6_addr *taddr6, u_long flags, int tlladdr,
struct sockaddr *sdl0)
{
nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
RT_DEFAULT_FIB);
}
#endif
caddr_t
nd6_ifptomac(struct ifnet *ifp)
{
switch (ifp->if_type) {
case IFT_ARCNET:
case IFT_ETHER:
case IFT_FDDI:
case IFT_IEEE1394:
case IFT_L2VLAN:
case IFT_INFINIBAND:
case IFT_BRIDGE:
case IFT_ISO88025:
return IF_LLADDR(ifp);
default:
return NULL;
}
}
struct dadq {
TAILQ_ENTRY(dadq) dad_list;
struct ifaddr *dad_ifa;
int dad_count; /* max NS to send */
int dad_ns_tcount; /* # of trials to send NS */
int dad_ns_ocount; /* NS sent so far */
int dad_ns_icount;
int dad_na_icount;
int dad_ns_lcount; /* looped back NS */
int dad_loopbackprobe; /* probing state for loopback detection */
struct callout dad_timer_ch;
struct vnet *dad_vnet;
u_int dad_refcnt;
#define ND_OPT_NONCE_LEN32 \
((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
};
static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
static VNET_DEFINE(struct rwlock, dad_rwlock);
#define V_dadq VNET(dadq)
#define V_dad_rwlock VNET(dad_rwlock)
#define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
#define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
#define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
#define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
static void
nd6_dad_add(struct dadq *dp)
{
DADQ_WLOCK();
TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
DADQ_WUNLOCK();
}
static void
nd6_dad_del(struct dadq *dp)
{
DADQ_WLOCK();
TAILQ_REMOVE(&V_dadq, dp, dad_list);
DADQ_WUNLOCK();
nd6_dad_rele(dp);
}
static struct dadq *
nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
{
struct dadq *dp;
DADQ_RLOCK();
TAILQ_FOREACH(dp, &V_dadq, dad_list) {
if (dp->dad_ifa != ifa)
continue;
/*
* Skip if the nonce matches the received one.
* +2 in the length is required because of type and
* length fields are included in a header.
*/
if (n != NULL &&
n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
ND_OPT_NONCE_LEN) == 0) {
dp->dad_ns_lcount++;
continue;
}
refcount_acquire(&dp->dad_refcnt);
break;
}
DADQ_RUNLOCK();
return (dp);
}
static void
nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns)
{
if (send_ns != 0)
nd6_dad_ns_output(dp);
callout_reset(&dp->dad_timer_ch, ticks,
(void (*)(void *))nd6_dad_timer, (void *)dp);
}
static void
nd6_dad_stoptimer(struct dadq *dp)
{
callout_drain(&dp->dad_timer_ch);
}
static void
nd6_dad_rele(struct dadq *dp)
{
if (refcount_release(&dp->dad_refcnt)) {
ifa_free(dp->dad_ifa);
free(dp, M_IP6NDP);
}
}
void
nd6_dad_init(void)
{
rw_init(&V_dad_rwlock, "nd6 DAD queue");
TAILQ_INIT(&V_dadq);
}
/*
* Start Duplicate Address Detection (DAD) for specified interface address.
*/
void
nd6_dad_start(struct ifaddr *ifa, int delay)
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct dadq *dp;
char ip6buf[INET6_ADDRSTRLEN];
KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
("starting DAD on non-tentative address %p", ifa));
/*
* If we don't need DAD, don't do it.
* There are several cases:
* - DAD is disabled globally or on the interface
* - the interface address is anycast
*/
if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
V_ip6_dad_count == 0 ||
(ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) {
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
return;
}
if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
(ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0)
return;
if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
/*
* DAD is already in progress. Let the existing entry
* finish it.
*/
nd6_dad_rele(dp);
return;
}
dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
if (dp == NULL) {
log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
"%s(%s)\n",
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
return;
}
callout_init(&dp->dad_timer_ch, 0);
#ifdef VIMAGE
dp->dad_vnet = curvnet;
#endif
nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
/*
* Send NS packet for DAD, ip6_dad_count times.
* Note that we must delay the first transmission, if this is the
* first packet to be sent from the interface after interface
* (re)initialization.
*/
dp->dad_ifa = ifa;
ifa_ref(dp->dad_ifa);
dp->dad_count = V_ip6_dad_count;
dp->dad_ns_icount = dp->dad_na_icount = 0;
dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
refcount_init(&dp->dad_refcnt, 1);
nd6_dad_add(dp);
nd6_dad_starttimer(dp, delay, 0);
}
/*
* terminate DAD unconditionally. used for address removals.
*/
void
nd6_dad_stop(struct ifaddr *ifa)
{
struct dadq *dp;
dp = nd6_dad_find(ifa, NULL);
if (!dp) {
/* DAD wasn't started yet */
return;
}
nd6_dad_stoptimer(dp);
/*
* The DAD queue entry may have been removed by nd6_dad_timer() while
* we were waiting for it to stop, so re-do the lookup.
*/
nd6_dad_rele(dp);
dp = nd6_dad_find(ifa, NULL);
if (dp == NULL)
return;
nd6_dad_del(dp);
nd6_dad_rele(dp);
}
static void
nd6_dad_timer(struct dadq *dp)
{
CURVNET_SET(dp->dad_vnet);
struct ifaddr *ifa = dp->dad_ifa;
struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
char ip6buf[INET6_ADDRSTRLEN];
KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
/* Do not need DAD for ifdisabled interface. */
log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
"ND6_IFF_IFDISABLED.\n", ifp->if_xname);
goto err;
}
if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
"%s(%s)\n",
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
goto err;
}
if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
"%s(%s)\n",
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
goto err;
}
/* Stop DAD if the interface is down even after dad_maxtry attempts. */
if ((dp->dad_ns_tcount > V_dad_maxtry) &&
(((ifp->if_flags & IFF_UP) == 0) ||
((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
nd6log((LOG_INFO, "%s: could not run DAD "
"because the interface was down or not running.\n",
if_name(ifa->ifa_ifp)));
goto err;
}
/* Need more checks? */
if (dp->dad_ns_ocount < dp->dad_count) {
/*
* We have more NS to go. Send NS packet for DAD.
*/
nd6_dad_starttimer(dp,
(long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
goto done;
} else {
/*
* We have transmitted sufficient number of DAD packets.
* See what we've got.
*/
if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
/* We've seen NS or NA, means DAD has failed. */
nd6_dad_duplicated(ifa, dp);
else if (V_dad_enhanced != 0 &&
dp->dad_ns_lcount > 0 &&
dp->dad_ns_lcount > dp->dad_loopbackprobe) {
/*
* Sec. 4.1 in RFC 7527 requires transmission of
* additional probes until the loopback condition
* becomes clear when a looped back probe is detected.
*/
log(LOG_ERR, "%s: a looped back NS message is "
"detected during DAD for %s. "
"Another DAD probes are being sent.\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa)));
dp->dad_loopbackprobe = dp->dad_ns_lcount;
/*
* Send an NS immediately and increase dad_count by
* V_nd6_mmaxtries - 1.
*/
dp->dad_count =
dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
nd6_dad_starttimer(dp,
(long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1);
goto done;
} else {
/*
* We are done with DAD. No NA came, no NS came.
* No duplicate address found. Check IFDISABLED flag
* again in case that it is changed between the
* beginning of this function and here.
*/
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
nd6log((LOG_DEBUG,
"%s: DAD complete for %s - no duplicates found\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
if (dp->dad_ns_lcount > 0)
log(LOG_ERR, "%s: DAD completed while "
"a looped back NS message is detected "
"during DAD for %s.\n",
if_name(ifa->ifa_ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa)));
}
}
err:
nd6_dad_del(dp);
done:
CURVNET_RESTORE();
}
static void
nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
struct ifnet *ifp;
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
"NS in/out/loopback=%d/%d/%d, NA in=%d\n",
if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
dp->dad_na_icount);
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
ia->ia6_flags |= IN6_IFF_DUPLICATED;
ifp = ifa->ifa_ifp;
log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
log(LOG_ERR, "%s: manual intervention required\n",
if_name(ifp));
/*
* If the address is a link-local address formed from an interface
* identifier based on the hardware address which is supposed to be
* uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
* operation on the interface SHOULD be disabled.
* [RFC 4862, Section 5.4.5]
*/
if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
struct in6_addr in6;
/*
* To avoid over-reaction, we only apply this logic when we are
* very sure that hardware addresses are supposed to be unique.
*/
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_FDDI:
case IFT_ATM:
case IFT_IEEE1394:
case IFT_INFINIBAND:
in6 = ia->ia_addr.sin6_addr;
if (in6_get_hw_ifid(ifp, &in6) == 0 &&
IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
log(LOG_ERR, "%s: possible hardware address "
"duplication detected, disable IPv6\n",
if_name(ifp));
}
break;
}
}
}
static void
nd6_dad_ns_output(struct dadq *dp)
{
struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
int i;
dp->dad_ns_tcount++;
if ((ifp->if_flags & IFF_UP) == 0) {
return;
}
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
return;
}
dp->dad_ns_ocount++;
if (V_dad_enhanced != 0) {
for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
dp->dad_nonce[i] = arc4random();
/*
* XXXHRS: Note that in the case that
* DupAddrDetectTransmits > 1, multiple NS messages with
* different nonces can be looped back in an unexpected
* order. The current implementation recognizes only
* the latest nonce on the sender side. Practically it
* should work well in almost all cases.
*/
}
nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
(uint8_t *)&dp->dad_nonce[0]);
}
static void
nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
{
struct dadq *dp;
if (ifa == NULL)
panic("ifa == NULL in nd6_dad_ns_input");
/* Ignore Nonce option when Enhanced DAD is disabled. */
if (V_dad_enhanced == 0)
ndopt_nonce = NULL;
dp = nd6_dad_find(ifa, ndopt_nonce);
if (dp == NULL)
return;
dp->dad_ns_icount++;
nd6_dad_rele(dp);
}
static void
nd6_dad_na_input(struct ifaddr *ifa)
{
struct dadq *dp;
if (ifa == NULL)
panic("ifa == NULL in nd6_dad_na_input");
dp = nd6_dad_find(ifa, NULL);
if (dp != NULL) {
dp->dad_na_icount++;
nd6_dad_rele(dp);
}
}
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