diff options
-rw-r--r-- | Documentation/networking/ip-sysctl.rst | 27 | ||||
-rw-r--r-- | include/linux/ipv6.h | 1 | ||||
-rw-r--r-- | include/uapi/linux/ipv6.h | 1 | ||||
-rw-r--r-- | net/ipv6/addrconf.c | 10 | ||||
-rw-r--r-- | net/ipv6/ndisc.c | 20 | ||||
-rw-r--r-- | tools/testing/selftests/net/Makefile | 1 | ||||
-rwxr-xr-x | tools/testing/selftests/net/ndisc_unsolicited_na_test.sh | 255 |
7 files changed, 314 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index b0024aa7b051..433f2e4a5fed 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -2467,6 +2467,33 @@ drop_unsolicited_na - BOOLEAN By default this is turned off. +accept_unsolicited_na - BOOLEAN + Add a new neighbour cache entry in STALE state for routers on receiving an + unsolicited neighbour advertisement with target link-layer address option + specified. This is as per router-side behavior documented in RFC9131. + This has lower precedence than drop_unsolicited_na. + + ==== ====== ====== ============================================== + drop accept fwding behaviour + ---- ------ ------ ---------------------------------------------- + 1 X X Drop NA packet and don't pass up the stack + 0 0 X Pass NA packet up the stack, don't update NC + 0 1 0 Pass NA packet up the stack, don't update NC + 0 1 1 Pass NA packet up the stack, and add a STALE + NC entry + ==== ====== ====== ============================================== + + This will optimize the return path for the initial off-link communication + that is initiated by a directly connected host, by ensuring that + the first-hop router which turns on this setting doesn't have to + buffer the initial return packets to do neighbour-solicitation. + The prerequisite is that the host is configured to send + unsolicited neighbour advertisements on interface bringup. + This setting should be used in conjunction with the ndisc_notify setting + on the host to satisfy this prerequisite. + + By default this is turned off. + enhanced_dad - BOOLEAN Include a nonce option in the IPv6 neighbor solicitation messages used for duplicate address detection per RFC7527. A received DAD NS will only signal diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 16870f86c74d..918bfea4ef5f 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -61,6 +61,7 @@ struct ipv6_devconf { __s32 suppress_frag_ndisc; __s32 accept_ra_mtu; __s32 drop_unsolicited_na; + __s32 accept_unsolicited_na; struct ipv6_stable_secret { bool initialized; struct in6_addr secret; diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index d4178dace0bf..549ddeaf788b 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -194,6 +194,7 @@ enum { DEVCONF_IOAM6_ID, DEVCONF_IOAM6_ID_WIDE, DEVCONF_NDISC_EVICT_NOCARRIER, + DEVCONF_ACCEPT_UNSOLICITED_NA, DEVCONF_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 1afc4c024981..6473dc84b71d 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5587,6 +5587,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_IOAM6_ID] = cnf->ioam6_id; array[DEVCONF_IOAM6_ID_WIDE] = cnf->ioam6_id_wide; array[DEVCONF_NDISC_EVICT_NOCARRIER] = cnf->ndisc_evict_nocarrier; + array[DEVCONF_ACCEPT_UNSOLICITED_NA] = cnf->accept_unsolicited_na; } static inline size_t inet6_ifla6_size(void) @@ -7038,6 +7039,15 @@ static const struct ctl_table addrconf_sysctl[] = { .extra2 = (void *)SYSCTL_ONE, }, { + .procname = "accept_unsolicited_na", + .data = &ipv6_devconf.accept_unsolicited_na, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = (void *)SYSCTL_ZERO, + .extra2 = (void *)SYSCTL_ONE, + }, + { /* sentinel */ } }; diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index fcb288b0ae13..254addad0dd3 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -979,6 +979,7 @@ static void ndisc_recv_na(struct sk_buff *skb) struct inet6_dev *idev = __in6_dev_get(dev); struct inet6_ifaddr *ifp; struct neighbour *neigh; + bool create_neigh; if (skb->len < sizeof(struct nd_msg)) { ND_PRINTK(2, warn, "NA: packet too short\n"); @@ -999,6 +1000,7 @@ static void ndisc_recv_na(struct sk_buff *skb) /* For some 802.11 wireless deployments (and possibly other networks), * there will be a NA proxy and unsolicitd packets are attacks * and thus should not be accepted. + * drop_unsolicited_na takes precedence over accept_unsolicited_na */ if (!msg->icmph.icmp6_solicited && idev && idev->cnf.drop_unsolicited_na) @@ -1039,7 +1041,23 @@ static void ndisc_recv_na(struct sk_buff *skb) in6_ifa_put(ifp); return; } - neigh = neigh_lookup(&nd_tbl, &msg->target, dev); + /* RFC 9131 updates original Neighbour Discovery RFC 4861. + * An unsolicited NA can now create a neighbour cache entry + * on routers if it has Target LL Address option. + * + * drop accept fwding behaviour + * ---- ------ ------ ---------------------------------------------- + * 1 X X Drop NA packet and don't pass up the stack + * 0 0 X Pass NA packet up the stack, don't update NC + * 0 1 0 Pass NA packet up the stack, don't update NC + * 0 1 1 Pass NA packet up the stack, and add a STALE + * NC entry + * Note that we don't do a (daddr == all-routers-mcast) check. + */ + create_neigh = !msg->icmph.icmp6_solicited && lladdr && + idev && idev->cnf.forwarding && + idev->cnf.accept_unsolicited_na; + neigh = __neigh_lookup(&nd_tbl, &msg->target, dev, create_neigh); if (neigh) { u8 old_flags = neigh->flags; diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 3fe2515aa616..af7f6e6ff182 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -36,6 +36,7 @@ TEST_PROGS += srv6_end_dt4_l3vpn_test.sh TEST_PROGS += srv6_end_dt6_l3vpn_test.sh TEST_PROGS += vrf_strict_mode_test.sh TEST_PROGS += arp_ndisc_evict_nocarrier.sh +TEST_PROGS += ndisc_unsolicited_na_test.sh TEST_PROGS_EXTENDED := in_netns.sh setup_loopback.sh setup_veth.sh TEST_PROGS_EXTENDED += toeplitz_client.sh toeplitz.sh TEST_GEN_FILES = socket nettest diff --git a/tools/testing/selftests/net/ndisc_unsolicited_na_test.sh b/tools/testing/selftests/net/ndisc_unsolicited_na_test.sh new file mode 100755 index 000000000000..f508657ee126 --- /dev/null +++ b/tools/testing/selftests/net/ndisc_unsolicited_na_test.sh @@ -0,0 +1,255 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +# This test is for the accept_unsolicited_na feature to +# enable RFC9131 behaviour. The following is the test-matrix. +# drop accept fwding behaviour +# ---- ------ ------ ---------------------------------------------- +# 1 X X Drop NA packet and don't pass up the stack +# 0 0 X Pass NA packet up the stack, don't update NC +# 0 1 0 Pass NA packet up the stack, don't update NC +# 0 1 1 Pass NA packet up the stack, and add a STALE +# NC entry + +ret=0 +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +PAUSE_ON_FAIL=no +PAUSE=no + +HOST_NS="ns-host" +ROUTER_NS="ns-router" + +HOST_INTF="veth-host" +ROUTER_INTF="veth-router" + +ROUTER_ADDR="2000:20::1" +HOST_ADDR="2000:20::2" +SUBNET_WIDTH=64 +ROUTER_ADDR_WITH_MASK="${ROUTER_ADDR}/${SUBNET_WIDTH}" +HOST_ADDR_WITH_MASK="${HOST_ADDR}/${SUBNET_WIDTH}" + +IP_HOST="ip -6 -netns ${HOST_NS}" +IP_HOST_EXEC="ip netns exec ${HOST_NS}" +IP_ROUTER="ip -6 -netns ${ROUTER_NS}" +IP_ROUTER_EXEC="ip netns exec ${ROUTER_NS}" + +tcpdump_stdout= +tcpdump_stderr= + +log_test() +{ + local rc=$1 + local expected=$2 + local msg="$3" + + if [ ${rc} -eq ${expected} ]; then + printf " TEST: %-60s [ OK ]\n" "${msg}" + nsuccess=$((nsuccess+1)) + else + ret=1 + nfail=$((nfail+1)) + printf " TEST: %-60s [FAIL]\n" "${msg}" + if [ "${PAUSE_ON_FAIL}" = "yes" ]; then + echo + echo "hit enter to continue, 'q' to quit" + read a + [ "$a" = "q" ] && exit 1 + fi + fi + + if [ "${PAUSE}" = "yes" ]; then + echo + echo "hit enter to continue, 'q' to quit" + read a + [ "$a" = "q" ] && exit 1 + fi +} + +setup() +{ + set -e + + local drop_unsolicited_na=$1 + local accept_unsolicited_na=$2 + local forwarding=$3 + + # Setup two namespaces and a veth tunnel across them. + # On end of the tunnel is a router and the other end is a host. + ip netns add ${HOST_NS} + ip netns add ${ROUTER_NS} + ${IP_ROUTER} link add ${ROUTER_INTF} type veth \ + peer name ${HOST_INTF} netns ${HOST_NS} + + # Enable IPv6 on both router and host, and configure static addresses. + # The router here is the DUT + # Setup router configuration as specified by the arguments. + # forwarding=0 case is to check that a non-router + # doesn't add neighbour entries. + ROUTER_CONF=net.ipv6.conf.${ROUTER_INTF} + ${IP_ROUTER_EXEC} sysctl -qw \ + ${ROUTER_CONF}.forwarding=${forwarding} + ${IP_ROUTER_EXEC} sysctl -qw \ + ${ROUTER_CONF}.drop_unsolicited_na=${drop_unsolicited_na} + ${IP_ROUTER_EXEC} sysctl -qw \ + ${ROUTER_CONF}.accept_unsolicited_na=${accept_unsolicited_na} + ${IP_ROUTER_EXEC} sysctl -qw ${ROUTER_CONF}.disable_ipv6=0 + ${IP_ROUTER} addr add ${ROUTER_ADDR_WITH_MASK} dev ${ROUTER_INTF} + + # Turn on ndisc_notify on host interface so that + # the host sends unsolicited NAs. + HOST_CONF=net.ipv6.conf.${HOST_INTF} + ${IP_HOST_EXEC} sysctl -qw ${HOST_CONF}.ndisc_notify=1 + ${IP_HOST_EXEC} sysctl -qw ${HOST_CONF}.disable_ipv6=0 + ${IP_HOST} addr add ${HOST_ADDR_WITH_MASK} dev ${HOST_INTF} + + set +e +} + +start_tcpdump() { + set -e + tcpdump_stdout=`mktemp` + tcpdump_stderr=`mktemp` + ${IP_ROUTER_EXEC} timeout 15s \ + tcpdump --immediate-mode -tpni ${ROUTER_INTF} -c 1 \ + "icmp6 && icmp6[0] == 136 && src ${HOST_ADDR}" \ + > ${tcpdump_stdout} 2> /dev/null + set +e +} + +cleanup_tcpdump() +{ + set -e + [[ ! -z ${tcpdump_stdout} ]] && rm -f ${tcpdump_stdout} + [[ ! -z ${tcpdump_stderr} ]] && rm -f ${tcpdump_stderr} + tcpdump_stdout= + tcpdump_stderr= + set +e +} + +cleanup() +{ + cleanup_tcpdump + ip netns del ${HOST_NS} + ip netns del ${ROUTER_NS} +} + +link_up() { + set -e + ${IP_ROUTER} link set dev ${ROUTER_INTF} up + ${IP_HOST} link set dev ${HOST_INTF} up + set +e +} + +verify_ndisc() { + local drop_unsolicited_na=$1 + local accept_unsolicited_na=$2 + local forwarding=$3 + + neigh_show_output=$(${IP_ROUTER} neigh show \ + to ${HOST_ADDR} dev ${ROUTER_INTF} nud stale) + if [ ${drop_unsolicited_na} -eq 0 ] && \ + [ ${accept_unsolicited_na} -eq 1 ] && \ + [ ${forwarding} -eq 1 ]; then + # Neighbour entry expected to be present for 011 case + [[ ${neigh_show_output} ]] + else + # Neighbour entry expected to be absent for all other cases + [[ -z ${neigh_show_output} ]] + fi +} + +test_unsolicited_na_common() +{ + # Setup the test bed, but keep links down + setup $1 $2 $3 + + # Bring the link up, wait for the NA, + # and add a delay to ensure neighbour processing is done. + link_up + start_tcpdump + + # Verify the neighbour table + verify_ndisc $1 $2 $3 + +} + +test_unsolicited_na_combination() { + test_unsolicited_na_common $1 $2 $3 + test_msg=("test_unsolicited_na: " + "drop_unsolicited_na=$1 " + "accept_unsolicited_na=$2 " + "forwarding=$3") + log_test $? 0 "${test_msg[*]}" + cleanup +} + +test_unsolicited_na_combinations() { + # Args: drop_unsolicited_na accept_unsolicited_na forwarding + + # Expect entry + test_unsolicited_na_combination 0 1 1 + + # Expect no entry + test_unsolicited_na_combination 0 0 0 + test_unsolicited_na_combination 0 0 1 + test_unsolicited_na_combination 0 1 0 + test_unsolicited_na_combination 1 0 0 + test_unsolicited_na_combination 1 0 1 + test_unsolicited_na_combination 1 1 0 + test_unsolicited_na_combination 1 1 1 +} + +############################################################################### +# usage + +usage() +{ + cat <<EOF +usage: ${0##*/} OPTS + -p Pause on fail + -P Pause after each test before cleanup +EOF +} + +############################################################################### +# main + +while getopts :pPh o +do + case $o in + p) PAUSE_ON_FAIL=yes;; + P) PAUSE=yes;; + h) usage; exit 0;; + *) usage; exit 1;; + esac +done + +# make sure we don't pause twice +[ "${PAUSE}" = "yes" ] && PAUSE_ON_FAIL=no + +if [ "$(id -u)" -ne 0 ];then + echo "SKIP: Need root privileges" + exit $ksft_skip; +fi + +if [ ! -x "$(command -v ip)" ]; then + echo "SKIP: Could not run test without ip tool" + exit $ksft_skip +fi + +if [ ! -x "$(command -v tcpdump)" ]; then + echo "SKIP: Could not run test without tcpdump tool" + exit $ksft_skip +fi + +# start clean +cleanup &> /dev/null + +test_unsolicited_na_combinations + +printf "\nTests passed: %3d\n" ${nsuccess} +printf "Tests failed: %3d\n" ${nfail} + +exit $ret |