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freebsd-dev/sys/netinet6/nd6_nbr.c
Mark Johnston 4caea9b169 icmp6: Count packets dropped due to an invalid hop limit 
Pad the icmp6stat structure so that we can add more counters in the
future without breaking compatibility again, last done in r358620.
Annotate the rarely executed error paths with __predict_false while
here.

Reviewed by:	bz, melifaro
Sponsored by:	NetApp, Inc.
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D26578
2020-10-19 17:07:19 +00:00

1568 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 <sys/param.h>
#include <sys/systm.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/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>
#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);
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)
/*
* 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 anycast, lladdrlen, proxy, rflag, tentative, tlladdr;
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_len < off + icmp6len) {
m = m_pullup(m, off + icmp6len);
if (m == NULL) {
IP6STAT_INC(ip6s_exthdrtoolong);
return;
}
}
ip6 = mtod(m, struct ip6_hdr *);
nd_ns = (struct nd_neighbor_solicit *)((caddr_t)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 (ND_IFINFO(ifp)->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.
*/
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;
}
lladdr = NULL;
lladdrlen = 0;
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. */
proxy = 0;
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)));
bads:
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;
struct ip6_hdr *ip6;
struct ifaddr *ifa;
struct llentry *ln;
struct mbuf *chain;
struct nd_neighbor_advert *nd_na;
struct in6_addr daddr6, taddr6;
struct sockaddr_in6 sin6;
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, lladdrlen, checklink;
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_len < off + icmp6len) {
m = m_pullup(m, off + icmp6len);
if (m == NULL) {
IP6STAT_INC(ip6s_exthdrtoolong);
return;
}
}
ip6 = mtod(m, struct ip6_hdr *);
nd_na = (struct nd_neighbor_advert *)((caddr_t)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;
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.
*/
ln = nd6_lookup(&taddr6, 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.
*/
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) {
memset(&sin6, 0, sizeof(sin6));
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_ETHER:
case IFT_IEEE1394:
case IFT_L2VLAN:
case IFT_INFINIBAND:
case IFT_BRIDGE:
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];
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_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);
dp->dad_ondadq = true;
DADQ_WUNLOCK();
}
static void
nd6_dad_del(struct dadq *dp)
{
DADQ_WLOCK();
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;
DADQ_WUNLOCK();
nd6_dad_rele(dp);
} else
DADQ_WUNLOCK();
}
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)
{
NET_EPOCH_ASSERT();
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];
struct epoch_tracker et;
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;
/* Add this to the dadq and add a reference for the dadq. */
refcount_init(&dp->dad_refcnt, 1);
nd6_dad_add(dp);
NET_EPOCH_ENTER(et);
nd6_dad_starttimer(dp, delay, 0);
NET_EPOCH_EXIT(et);
}
/*
* 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);
nd6_dad_del(dp);
/* Release this function's reference, acquired by nd6_dad_find(). */
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];
struct epoch_tracker et;
KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
NET_EPOCH_ENTER(et);
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:
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];
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_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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