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freebsd-src/sys/netinet6/nd6_nbr.c
T
Vinícius Ferrão ede7728078 netinet6: Use memcpy/memset/memcmp for consistency 
Convert the remaining bzero()/bcopy()/bcmp() calls in the neighbor
discovery handlers to memset()/memcpy()/memcmp().

No functional change intended.

Reviewed by:	glebius, pouria
Sponsored by:	VersatusHPC
Differential Revision:	https://reviews.freebsd.org/D58177
2026-11-03 00:03:03 +03:30

1926 lines
53 KiB
C
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/*-
* 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 "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/counter.h>
#include <sys/eventhandler.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/if_private.h>
#include <net/route.h>
#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>
#include <machine/atomic.h>
#define SDL(s) ((struct sockaddr_dl *)s)
MALLOC_DECLARE(M_IP6NDP);
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);
static void nd6_dad_stoptimer(struct dadq *);
static void nd6_dad_timer(void *);
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 void nd6_queue_add(struct ifaddr *, struct in6_addr *,
struct in6_addr *, struct sockaddr_dl *, int, uint32_t);
static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *,
const struct in6_addr *, struct sockaddr_dl *);
VNET_DEFINE_STATIC(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.");
VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
transmit DAD packet */
#define V_dad_maxtry VNET(dad_maxtry)
VNET_DEFINE_STATIC(int, nd6_onlink_ns_rfc4861) = 0;
#define V_nd6_onlink_ns_rfc4861 VNET(nd6_onlink_ns_rfc4861)
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861,
nd6_onlink_ns_rfc4861, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(nd6_onlink_ns_rfc4861), 0,
"Accept 'on-link' ICMPv6 NS messages in compliance with RFC 4861");
struct nd_queue {
TAILQ_ENTRY(nd_queue) ndq_list;
struct ifaddr *ndq_ifa;
struct in6_addr ndq_daddr;
struct in6_addr ndq_taddr;
struct sockaddr_dl ndq_sdl;
uint32_t ndq_flags;
struct callout ndq_callout;
};
/*
* 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;
struct ip6_hdr *ip6;
struct nd_neighbor_solicit *nd_ns;
struct in6_addr daddr6, myaddr6, saddr6, taddr6;
struct ifaddr *ifa;
struct sockaddr_dl proxydl;
union nd_opts ndopts;
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
char *lladdr;
int rflag, tentative, tlladdr;
u_int lladdr_pad, lladdrlen;
uint32_t dflags;
ifa = NULL;
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
ifp = m->m_pkthdr.rcvif;
ip6 = mtod(m, struct ip6_hdr *);
if (__predict_false(ip6->ip6_hlim != 255)) {
ICMP6STAT_INC(icp6s_invlhlim);
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 bads;
}
if ((m = m_pullup(m, off + icmp6len)) == NULL) {
IP6STAT_INC(ip6s_exthdrtoolong);
return;
}
ip6 = mtod(m, struct ip6_hdr *);
nd_ns = (struct nd_neighbor_solicit *)((char *)ip6 + off);
saddr6 = ip6->ip6_src;
daddr6 = ip6->ip6_dst;
taddr6 = nd_ns->nd_ns_target;
if (in6_setscope(&taddr6, ifp, NULL) != 0)
goto bad;
rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
rflag = 0;
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.
*/
memset(&src_sa6, 0, 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;
}
lladdr = NULL;
lladdrlen = 0;
lladdr_pad = nd6_lladdr_opt_pad(ifp);
if (ndopts.nd_opts_src_lladdr) {
lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1) + lladdr_pad;
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.
*/
tlladdr = 0;
if (IN6_IS_ADDR_MULTICAST(&daddr6))
tlladdr |= ND6_NA_OPT_LLA;
/*
* 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);
if (ifa != NULL)
tlladdr |= ND6_NA_CARP_MASTER;
} else
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
/* (2) check. */
dflags = 0;
if (ifa == NULL) {
if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL)
dflags |= ND6_QUEUE_FLAG_PROXY;
}
if (ifa == NULL) {
/*
* We've got an NS packet, and we don't have that address
* assigned for us. We MUST silently ignore it.
* See RFC2461 7.2.3.
*/
goto freeit;
}
if ((((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST) != 0)
dflags |= ND6_QUEUE_FLAG_ANYCAST;
myaddr6 = *IFA_IN6(ifa);
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 %u)\n",
ip6_sprintf(ip6bufs, &taddr6),
ifp->if_addrlen, lladdrlen - 2 - lladdr_pad));
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 Target Address is either an anycast address or a unicast
* address for which the node is providing proxy service, or the Target
* Link-Layer Address option is not included, the Override flag SHOULD
* be set to zero. Otherwise, the Override flag SHOULD be set to one.
*/
if (dflags == 0 && (tlladdr & ND6_NA_OPT_LLA) != 0)
rflag |= ND_NA_FLAG_OVERRIDE;
/*
* If the source address is unspecified address, entries must not
* be created or updated.
* It looks that sender is performing DAD. nd6_na_output() will
* send 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)) {
nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
ND_NEIGHBOR_SOLICIT, 0);
rflag |= ND_NA_FLAG_SOLICITED;
}
/*
* RFC 4861, anycast or proxy NA sent in response to a NS SHOULD
* be delayed by a random time between 0 and MAX_ANYCAST_DELAY_TIME
* to reduce the probability of network congestion.
*/
if (dflags == 0)
nd6_na_output_fib(ifp, &saddr6, &taddr6, rflag, tlladdr, NULL, M_GETFIB(m));
else
nd6_queue_add(ifa, &saddr6, &taddr6, &proxydl, arc4random() %
(MAX_ANYCAST_DELAY_TIME * hz), dflags);
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)));
bads:
ICMP6STAT_INC(icp6s_badns);
if (ifa != NULL)
ifa_free(ifa);
m_freem(m);
}
static struct ifaddr *
nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6,
struct sockaddr_dl *sdl)
{
struct ifaddr *ifa;
struct llentry *ln;
ifa = NULL;
ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp);
if (ln == NULL)
return (ifa);
if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) {
link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type);
sdl->sdl_alen = ifp->if_addrlen;
memcpy(&sdl->sdl_data, ln->ll_addr, ifp->if_addrlen);
LLE_RUNLOCK(ln);
ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
} else
LLE_RUNLOCK(ln);
return (ifa);
}
/*
* 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;
NET_EPOCH_ASSERT();
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);
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 (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
m->m_flags |= M_MCAST;
im6o.im6o_multicast_ifp = ifp;
im6o.im6o_multicast_hlim = 255;
im6o.im6o_multicast_loop = 0;
}
if (nonce == NULL) {
char ip6buf[INET6_ADDRSTRLEN];
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) {
int error;
error = in6_selectsrc_nbr(fibnum, &ip6->ip6_dst, &im6o,
ifp, &ip6->ip6_src);
if (error) {
nd6log((LOG_DEBUG, "%s: source can't be "
"determined: dst=%s, error=%d\n", __func__,
ip6_sprintf(ip6buf, &ip6->ip6_dst),
error));
goto bad;
}
} else
ip6->ip6_src = *saddr6;
if (ifp->if_carp != NULL) {
/*
* Check that selected source address belongs to
* CARP addresses.
*/
if (ifa == NULL)
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
&ip6->ip6_src);
/*
* Do not send NS for CARP address if we are not
* the CARP master.
*/
if (ifa != NULL && ifa->ifa_carp != NULL &&
!(*carp_master_p)(ifa)) {
nd6log((LOG_DEBUG,
"nd6_ns_output: NS from BACKUP CARP address %s\n",
ip6_sprintf(ip6buf, &ip6->ip6_src)));
ifa_free(ifa);
goto bad;
}
}
if (ifa != NULL)
ifa_free(ifa);
} 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.
*/
memset(&ip6->ip6_src, 0, 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) {
struct nd_opt_hdr *nd_opt;
char *mac;
int optlen;
u_int pad;
mac = NULL;
if (ifp->if_carp)
mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src);
if (mac == NULL)
mac = nd6_ifptomac(ifp);
if (mac != NULL) {
nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
pad = nd6_lladdr_opt_pad(ifp);
optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
/* 8 byte alignments... */
optlen = (optlen + 7) & ~7;
m->m_pkthdr.len += optlen;
m->m_len += optlen;
icmp6len += optlen;
memset(nd_opt, 0, optlen);
nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
memcpy((char *)(nd_opt + 1) + pad, mac,
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(nd_opt, optlen);
nd_opt->nd_opt_type = ND_OPT_NONCE;
nd_opt->nd_opt_len = optlen >> 3;
bcopy(nonce, 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_INC2(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)
*/
void
nd6_na_input(struct mbuf *m, int off, int icmp6len)
{
struct ifnet *ifp;
struct ip6_hdr *ip6;
struct ifaddr *ifa;
struct llentry *ln;
struct mbuf *chain;
struct nd_neighbor_advert *nd_na;
struct in6_addr daddr6, taddr6;
union nd_opts ndopts;
u_char linkhdr[LLE_MAX_LINKHDR];
char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
char *lladdr;
size_t linkhdrsize;
int flags, is_override, is_router, is_solicited;
int lladdr_off, checklink;
u_int lladdr_pad, lladdrlen;
bool flush_holdchain = false;
NET_EPOCH_ASSERT();
chain = NULL;
ln = NULL;
checklink = 0;
/* RFC 6980: Nodes MUST silently ignore fragments */
if(m->m_flags & M_FRAGMENTED)
goto freeit;
ifp = m->m_pkthdr.rcvif;
ip6 = mtod(m, struct ip6_hdr *);
if (__predict_false(ip6->ip6_hlim != 255)) {
ICMP6STAT_INC(icp6s_invlhlim);
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;
}
if ((m = m_pullup(m, off + icmp6len)) == NULL) {
IP6STAT_INC(ip6s_exthdrtoolong);
return;
}
ip6 = mtod(m, struct ip6_hdr *);
nd_na = (struct nd_neighbor_advert *)((char *)ip6 + off);
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);
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;
}
daddr6 = ip6->ip6_dst;
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;
}
lladdr = NULL;
lladdrlen = 0;
lladdr_pad = nd6_lladdr_opt_pad(ifp);
if (ndopts.nd_opts_tgt_lladdr) {
lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1) + lladdr_pad;
lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
}
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
if (ifa != NULL && ifa->ifa_carp != NULL) {
/*
* Silently ignore NAs for CARP addresses if we are not
* the CARP master.
*/
if (!(*carp_master_p)(ifa)) {
nd6log((LOG_DEBUG,
"nd6_na_input: NA for BACKUP CARP address %s\n",
ip6_sprintf(ip6bufs, &taddr6)));
ifa_free(ifa);
goto freeit;
}
}
/*
* 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 %u)\n", ip6_sprintf(ip6bufs, &taddr6),
ifp->if_addrlen, lladdrlen - 2 - lladdr_pad));
goto bad;
}
/*
* If no neighbor cache entry is found, NA SHOULD silently be
* discarded.
*/
ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
if (ln == NULL) {
goto freeit;
}
/*
* Do not try to override static entry.
*/
if (ln->la_flags & LLE_STATIC)
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.
*/
if (!nd6_try_set_entry_addr(ifp, ln, lladdr))
goto freeit;
flush_holdchain = true;
if (is_solicited)
nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
else
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
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 (memcmp(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)
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) &&
(nd6_ifp->if_inet6->nd_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)
chain = nd6_grab_holdchain(ln);
freeit:
if (ln != NULL)
LLE_WUNLOCK(ln);
if (chain != NULL)
nd6_flush_holdchain(ifp, ln, chain);
if (flush_holdchain)
nd6_flush_children_holdchain(ifp, ln);
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
*
* tlladdr:
* - 0x01 if include target link-layer address
* - 0x02 if target address is CARP MASTER
* 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;
NET_EPOCH_ASSERT();
int icmp6len, maxlen, error;
char *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);
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 = in6addr_linklocal_allnodes;
if (in6_setscope(&daddr6, ifp, NULL))
goto bad;
flags &= ~ND_NA_FLAG_SOLICITED;
}
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;
}
ip6->ip6_dst = daddr6;
error = in6_selectsrc_nbr(fibnum, &daddr6, &im6o, ifp, &ip6->ip6_src);
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;
}
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 */
/*
* If we respond from CARP address, we need to prepare mac address
* for carp_output().
*/
if (ifp->if_carp && (tlladdr & ND6_NA_CARP_MASTER))
mac = (*carp_macmatch6_p)(ifp, m, taddr6);
/*
* "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 & ND6_NA_OPT_LLA) {
/*
* 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 (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 & ND6_NA_OPT_LLA) && mac != NULL) {
u_int pad = nd6_lladdr_opt_pad(ifp);
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;
memset(nd_opt, 0, optlen);
nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
nd_opt->nd_opt_len = optlen >> 3;
memcpy((char *)(nd_opt + 1) + pad, mac, 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_INC2(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
char *
nd6_ifptomac(struct ifnet *ifp)
{
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_IEEE1394:
case IFT_L2VLAN:
case IFT_INFINIBAND:
case IFT_BRIDGE:
return IF_LLADDR(ifp);
default:
return NULL;
}
}
/*
* Number of reserved octets between the header of an ND link-layer
* address option and the link-layer address itself. On IPoIB links
* two zero octets are prepended to the 20-octet link-layer address
* to fill the 24-octet option (RFC 4391, section 9.3); on all other
* link types the address immediately follows the option header.
*/
u_int
nd6_lladdr_opt_pad(struct ifnet *ifp)
{
switch (ifp->if_type) {
case IFT_INFINIBAND:
case IFT_INFINIBANDLAG:
return (2);
default:
return (0);
}
}
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];
bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
};
VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
#define V_dadq VNET(dadq)
#define V_dad_rwlock VNET(dad_rwlock)
#define DADQ_LOCKPTR() (&V_dad_rwlock)
#define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue")
#define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR())
#define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR())
#define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR())
#define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR())
#define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED);
#define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED);
#define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED);
static void
nd6_dad_add(struct dadq *dp)
{
DADQ_WLOCK_ASSERT();
TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
dp->dad_ondadq = true;
}
static void
nd6_dad_del(struct dadq *dp)
{
DADQ_WLOCK_ASSERT();
if (dp->dad_ondadq) {
/*
* Remove dp from the dadq and release the dadq's
* reference.
*/
TAILQ_REMOVE(&V_dadq, dp, dad_list);
dp->dad_ondadq = false;
nd6_dad_rele(dp);
}
}
static struct dadq *
nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
{
struct dadq *dp;
DADQ_LOCK_ASSERT();
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;
}
break;
}
return (dp);
}
static void
nd6_dad_starttimer(struct dadq *dp, int ticks)
{
DADQ_WLOCK_ASSERT();
callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, 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)) {
KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp));
ifa_free(dp->dad_ifa);
free(dp, M_IP6NDP);
}
}
void
nd6_dad_init(void)
{
DADQ_LOCK_INIT();
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 ||
(ifa->ifa_ifp->if_inet6->nd_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 ||
(ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) != 0)
return;
DADQ_WLOCK();
if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
/*
* DAD is already in progress. Let the existing entry
* finish it.
*/
DADQ_WUNLOCK();
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_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(),
CALLOUT_RETURNUNLOCKED);
#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;
/* Add this to the dadq and add a reference for the dadq. */
refcount_init(&dp->dad_refcnt, 1);
nd6_dad_add(dp);
nd6_dad_starttimer(dp, delay);
DADQ_WUNLOCK();
}
/*
* terminate DAD unconditionally. used for address removals.
*/
void
nd6_dad_stop(struct ifaddr *ifa)
{
struct dadq *dp;
DADQ_WLOCK();
dp = nd6_dad_find(ifa, NULL);
if (dp == NULL) {
DADQ_WUNLOCK();
/* DAD wasn't started yet */
return;
}
/*
* Acquire a temporary reference so that we can safely stop the callout.
*/
(void)refcount_acquire(&dp->dad_refcnt);
nd6_dad_del(dp);
DADQ_WUNLOCK();
nd6_dad_stoptimer(dp);
nd6_dad_rele(dp);
}
static void
nd6_dad_timer(void *arg)
{
struct dadq *dp = arg;
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];
struct epoch_tracker et;
CURVNET_SET(dp->dad_vnet);
KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
NET_EPOCH_ENTER(et);
if (ifp->if_inet6->nd_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)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
nd6_dad_ns_output(dp);
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)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
nd6_dad_ns_output(dp);
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.
*
* Reset DAD failures counter if using stable addresses.
*/
if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) == 0) {
ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY))
atomic_store_int(&DAD_FAILURES(ifp), 0);
/*
* RFC 9131 Section 6.1.2: The first advertisement
* SHOULD be sent as soon as an address changes the
* state from tentative to preferred.
*/
nd6_grand_start(ifa, ND6_QUEUE_FLAG_NEWGUA);
}
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);
DADQ_WUNLOCK();
done:
NET_EPOCH_EXIT(et);
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];
ifp = ifa->ifa_ifp;
log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
"NS in/out/loopback=%d/%d/%d, NA in=%d\n",
if_name(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;
log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
/*
* For RFC 7217 stable addresses, increment failure counter here if we still have retries.
* More addresses will be generated as long as retries are not exhausted.
*/
if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
if (dad_failures <= V_ip6_stableaddr_maxretries) {
atomic_add_int(&DAD_FAILURES(ifp), 1);
/* if retries exhausted, output an informative error message */
if (dad_failures == V_ip6_stableaddr_maxretries)
log(LOG_ERR, "%s: manual intervention required, consider disabling \"stableaddr\" on the interface"
" or checking hostuuid for uniqueness\n",
if_name(ifp));
}
} else {
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_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)) {
ifp->if_inet6->nd_flags |= ND6_IFF_IFDISABLED;
log(LOG_ERR, "%s: possible hardware address "
"duplication detected, disable IPv6\n",
if_name(ifp));
}
break;
}
}
}
/*
* Transmit a neighbour solicitation for the purpose of DAD. Returns with the
* DAD queue unlocked.
*/
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;
DADQ_WLOCK_ASSERT();
dp->dad_ns_tcount++;
if ((ifp->if_flags & IFF_UP) == 0) {
DADQ_WUNLOCK();
return;
}
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
DADQ_WUNLOCK();
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.
*/
}
DADQ_WUNLOCK();
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;
DADQ_RLOCK();
dp = nd6_dad_find(ifa, ndopt_nonce);
if (dp != NULL)
dp->dad_ns_icount++;
DADQ_RUNLOCK();
}
static void
nd6_dad_na_input(struct ifaddr *ifa)
{
struct dadq *dp;
if (ifa == NULL)
panic("ifa == NULL in nd6_dad_na_input");
DADQ_RLOCK();
dp = nd6_dad_find(ifa, NULL);
if (dp != NULL)
dp->dad_na_icount++;
DADQ_RUNLOCK();
}
static void
nd6_queue_rel(void *arg)
{
struct nd_queue *ndq = arg;
struct ifaddr *ifa;
ifa = ndq->ndq_ifa;
IF_ADDR_WLOCK_ASSERT(ifa->ifa_ifp);
/* Remove ndq from the nd_queue list and free it */
TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
IF_ADDR_WUNLOCK(ifa->ifa_ifp);
free(ndq, M_IP6NDP);
ifa_free(ifa);
}
static void
nd6_queue_timer(void *arg)
{
struct nd_queue *ndq = arg;
struct ifaddr *ifa = ndq->ndq_ifa;
struct ifnet *ifp;
struct in6_addr daddr, taddr;
struct sockaddr_dl sdl;
struct epoch_tracker et;
int delay, tlladdr;
u_long flags;
bool proxy;
KASSERT(ifa != NULL, ("ND6 queue entry %p with no address", ndq));
ifp = ifa->ifa_ifp;
CURVNET_SET(ifp->if_vnet);
NET_EPOCH_ENTER(et);
daddr = ndq->ndq_daddr;
taddr = ndq->ndq_taddr;
tlladdr = ND6_NA_OPT_LLA;
flags = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0 && V_ip6_norbit_raif)
flags &= ~ND_NA_FLAG_ROUTER;
/*
* RFC 9131 Section 6.1.2: If the address is preferred,
* then the Override flag SHOULD NOT be set.
*/
if ((ndq->ndq_flags & ND6_QUEUE_FLAG_NEWGUA) != 0) {
/*
* XXX: If the address is in the Optimistic state,
* then the Override flag MUST NOT be set.
* We don't support RFC 4429 yet.
*/
if ((ifp->if_inet6->nd_flags & ND6_IFF_PREFER_SOURCE) == 0)
flags |= ND_NA_FLAG_OVERRIDE;
}
/*
* RFC 4861 Section 7.2.6: if link-layer address changed,
* The Override flag MAY be set to either zero or one.
*/
if ((ndq->ndq_flags & ND6_QUEUE_FLAG_LLADDR) != 0)
flags |= ND_NA_FLAG_OVERRIDE;
/* anycast advertisement delay rule (RFC 4861 7.2.7, SHOULD) */
if ((ndq->ndq_flags & ND6_QUEUE_FLAG_ANYCAST) != 0)
flags |= ND_NA_FLAG_SOLICITED;
/* proxy advertisement delay rule (RFC 4861 7.2.8, SHOULD) */
proxy = false;
if ((ndq->ndq_flags & ND6_QUEUE_FLAG_PROXY) != 0) {
flags |= ND_NA_FLAG_SOLICITED;
sdl = ndq->ndq_sdl;
proxy = true;
}
/*
* if it was GRAND, wait at least a RetransTimer
* before removing from queue.
*/
if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) != 0) {
delay = ifp->if_inet6->nd_retrans * hz / 1000;
callout_reset(&ndq->ndq_callout, delay, nd6_queue_rel, ndq);
IF_ADDR_WUNLOCK(ifp);
} else
nd6_queue_rel(ndq);
if (__predict_true(in6_setscope(&daddr, ifp, NULL) == 0))
nd6_na_output_fib(ifp, &daddr, &taddr, flags, tlladdr,
proxy ? (struct sockaddr *)&sdl : NULL, ifp->if_fib);
NET_EPOCH_EXIT(et);
CURVNET_RESTORE();
}
/*
* Queue a delayed IPv6 Neighbor Advertisement.
*
* daddr: destination address (who the NA is sent to)
* taddr: target address being advertised (used for proxy NAs)
* sdl: link-layer address (used for proxy NAs)
*/
static void
nd6_queue_add(struct ifaddr *ifa, struct in6_addr *daddr,
struct in6_addr *taddr, struct sockaddr_dl *sdl, int delay, uint32_t flags)
{
struct nd_queue *ndq = NULL;
struct ifnet *ifp;
struct in6_ifextra *ext;
char ip6buf[INET6_ADDRSTRLEN];
NET_EPOCH_ASSERT();
ifp = ifa->ifa_ifp;
ext = ifp->if_inet6;
IF_ADDR_WLOCK(ifp);
/*
* if request comes from GRAND, check whether another delayed
* GRAND NA exists in the queue.
* If it exists, cancel previous one and reuse its ndq.
*/
if ((flags & ND6_QUEUE_GRAND_MASK) != 0) {
TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
if (ndq->ndq_ifa == ifa &&
(flags & ND6_QUEUE_GRAND_MASK) != 0)
break;
}
}
if (ndq == NULL) {
ndq = malloc(sizeof(*ndq), M_IP6NDP, M_NOWAIT | M_ZERO);
if (ndq == NULL) {
log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n",
__func__, ip6_sprintf(ip6buf, IFA_IN6(ifa)),
ifp ? if_name(ifp) : "???");
IF_ADDR_WUNLOCK(ifp);
return;
}
callout_init_mtx(&ndq->ndq_callout, &ifp->if_addr_lock,
CALLOUT_TRYLOCK | CALLOUT_RETURNUNLOCKED);
ifa_ref(ifa);
ndq->ndq_ifa = ifa;
TAILQ_INSERT_TAIL(&ext->nd_queue, ndq, ndq_list);
}
memcpy(&ndq->ndq_daddr, daddr, sizeof(struct in6_addr));
/*
* For proxy NAs, the target address (taddr) being advertised differs from
* the interface address (ifa), so we must explicitly store both the proxy
* target address and its link-layer address (sdl).
* For non-proxy NAs, use the interface address (ifa) itself as the target.
*/
if ((flags & ND6_QUEUE_FLAG_PROXY) != 0) {
memcpy(&ndq->ndq_taddr, taddr, sizeof(struct in6_addr));
memcpy(&ndq->ndq_sdl, sdl, sizeof(struct sockaddr_dl));
} else
memcpy(&ndq->ndq_taddr, IFA_IN6(ifa), sizeof(struct in6_addr));
ndq->ndq_flags = flags;
nd6log((LOG_DEBUG, "%s: delay IPv6 NA for %s\n", if_name(ifp),
ip6_sprintf(ip6buf, IFA_IN6(ifa))));
callout_reset(&ndq->ndq_callout, delay, nd6_queue_timer, ndq);
IF_ADDR_WUNLOCK(ifp);
}
/*
* Start Gratuitous Neighbor Discovery (GRAND) for specified address.
* Called after DAD completes and by interface link layer change event.
*/
void
nd6_grand_start(struct ifaddr *ifa, uint32_t flags)
{
struct nd_queue *ndq;
struct in6_ifextra *ext = ifa->ifa_ifp->if_inet6;
struct in6_addr daddr = IN6ADDR_ANY_INIT;
int delay, count = 0;
NET_EPOCH_ASSERT();
/* If we don't need GRAND, don't do it. */
if (V_ip6_grand_count == 0 ||
ifa->ifa_carp != NULL)
return;
/* Check if new address is global */
if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0 &&
in6_addrscope(IFA_IN6(ifa)) != IPV6_ADDR_SCOPE_GLOBAL)
return;
/*
* RFC 9131 Section 6.1.2: These advertisements MUST be
* separated by at least RetransTimer seconds.
*/
TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
/*
* RFC 9131 Section 6.1.2: a node SHOULD send
* up to MAX_NEIGHBOR_ADVERTISEMENT Neighbor Advertisement messages.
* Make sure we don't queue GRAND more than V_ip6_grand_count
* per interface.
* Since this limitation only applies to GRAND, don't
* count non-GRAND ndq.
*/
if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) == 0)
continue;
count++;
if (count >= V_ip6_grand_count)
return;
}
/*
* RFC 9131 Section 6.1.2: if new global address added,
* use the all-routers multicast address.
*/
if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0)
daddr = in6addr_linklocal_allrouters;
/*
* RFC 4861 Section 7.2.6: if link-layer address changed,
* use the all-nodes multicast address.
*/
if ((flags & ND6_QUEUE_FLAG_LLADDR) != 0)
daddr = in6addr_linklocal_allnodes;
delay = ext->nd_retrans * hz / 1000;
nd6_queue_add(ifa, &daddr, NULL, NULL, count * delay, flags);
}
/*
* drain nd6 queue. used for address removals.
*/
void
nd6_queue_stop(struct ifaddr *ifa)
{
struct nd_queue *ndq, *dndq;
struct ifnet *ifp;
ifp = ifa->ifa_ifp;
IF_ADDR_WLOCK(ifp);
TAILQ_FOREACH_SAFE(ndq, &ifp->if_inet6->nd_queue, ndq_list, dndq) {
if (ndq->ndq_ifa != ifa)
continue;
callout_stop(&ndq->ndq_callout);
/* Remove ndq from the nd_queue list and free it */
TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
free(ndq, M_IP6NDP);
ifa_free(ifa);
}
IF_ADDR_WUNLOCK(ifp);
}
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