diff options
| -rw-r--r-- | net/ipv6/seg6_iptunnel.c | 34 | ||||
| -rw-r--r-- | tools/testing/selftests/net/Makefile | 1 | ||||
| -rwxr-xr-x | tools/testing/selftests/net/srv6_iptunnel_cache.sh | 197 |
3 files changed, 221 insertions, 11 deletions
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 3e1b9991131a..d6a0f7df9080 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -48,7 +48,8 @@ static size_t seg6_lwt_headroom(struct seg6_iptunnel_encap *tuninfo) } struct seg6_lwt { - struct dst_cache cache; + struct dst_cache cache_input; + struct dst_cache cache_output; struct seg6_iptunnel_encap tuninfo[]; }; @@ -488,7 +489,7 @@ static int seg6_input_core(struct net *net, struct sock *sk, slwt = seg6_lwt_lwtunnel(lwtst); local_bh_disable(); - dst = dst_cache_get(&slwt->cache); + dst = dst_cache_get(&slwt->cache_input); local_bh_enable(); err = seg6_do_srh(skb, dst); @@ -504,7 +505,7 @@ static int seg6_input_core(struct net *net, struct sock *sk, /* cache only if we don't create a dst reference loop */ if (!dst->error && lwtst != dst->lwtstate) { local_bh_disable(); - dst_cache_set_ip6(&slwt->cache, dst, + dst_cache_set_ip6(&slwt->cache_input, dst, &ipv6_hdr(skb)->saddr); local_bh_enable(); } @@ -564,7 +565,7 @@ static int seg6_output_core(struct net *net, struct sock *sk, slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate); local_bh_disable(); - dst = dst_cache_get(&slwt->cache); + dst = dst_cache_get(&slwt->cache_output); local_bh_enable(); err = seg6_do_srh(skb, dst); @@ -591,7 +592,7 @@ static int seg6_output_core(struct net *net, struct sock *sk, /* cache only if we don't create a dst reference loop */ if (orig_dst->lwtstate != dst->lwtstate) { local_bh_disable(); - dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); + dst_cache_set_ip6(&slwt->cache_output, dst, &fl6.saddr); local_bh_enable(); } @@ -701,11 +702,13 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, slwt = seg6_lwt_lwtunnel(newts); - err = dst_cache_init(&slwt->cache, GFP_ATOMIC); - if (err) { - kfree(newts); - return err; - } + err = dst_cache_init(&slwt->cache_input, GFP_ATOMIC); + if (err) + goto err_free_newts; + + err = dst_cache_init(&slwt->cache_output, GFP_ATOMIC); + if (err) + goto err_destroy_input; memcpy(&slwt->tuninfo, tuninfo, tuninfo_len); @@ -720,11 +723,20 @@ static int seg6_build_state(struct net *net, struct nlattr *nla, *ts = newts; return 0; + +err_destroy_input: + dst_cache_destroy(&slwt->cache_input); +err_free_newts: + kfree(newts); + return err; } static void seg6_destroy_state(struct lwtunnel_state *lwt) { - dst_cache_destroy(&seg6_lwt_lwtunnel(lwt)->cache); + struct seg6_lwt *slwt = seg6_lwt_lwtunnel(lwt); + + dst_cache_destroy(&slwt->cache_input); + dst_cache_destroy(&slwt->cache_output); } static int seg6_fill_encap_info(struct sk_buff *skb, diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 605c54c0e8a3..c709523c99c6 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -89,6 +89,7 @@ TEST_PROGS := \ srv6_end_x_next_csid_l3vpn_test.sh \ srv6_hencap_red_l3vpn_test.sh \ srv6_hl2encap_red_l2vpn_test.sh \ + srv6_iptunnel_cache.sh \ stress_reuseport_listen.sh \ tcp_fastopen_backup_key.sh \ test_bpf.sh \ diff --git a/tools/testing/selftests/net/srv6_iptunnel_cache.sh b/tools/testing/selftests/net/srv6_iptunnel_cache.sh new file mode 100755 index 000000000000..62638ab679d9 --- /dev/null +++ b/tools/testing/selftests/net/srv6_iptunnel_cache.sh @@ -0,0 +1,197 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# author: Andrea Mayer <andrea.mayer@uniroma2.it> + +# This test verifies that the seg6 lwtunnel does not share the dst_cache +# between the input (forwarding) and output (locally generated) paths. +# +# A shared dst_cache allows a forwarded packet to populate the cache and a +# subsequent locally generated packet to silently reuse that entry, bypassing +# its own route lookup. To expose this, the SID is made reachable only for +# forwarded traffic (via an ip rule matching iif) and blackholed for everything +# else. A local ping on ns_router must always hit the blackhole; +# if it succeeds after a forwarded packet has populated the +# cache, the bug is confirmed. +# +# Both forwarded and local packets are pinned to the same CPU with taskset, +# since dst_cache is per-cpu. +# +# +# +--------------------+ +--------------------+ +# | ns_src | | ns_dst | +# | | | | +# | veth-s0 | | veth-d0 | +# | fd00::1/64 | | fd01::2/64 | +# +-------+------------+ +----------+---------+ +# | | +# | +--------------------+ | +# | | ns_router | | +# | | | | +# +------------+ veth-r0 veth-r1 +--------------+ +# | fd00::2 fd01::1 | +# +--------------------+ +# +# +# ns_router: encap (main table) +# +---------+---------------------------------------+ +# | dst | action | +# +---------+---------------------------------------+ +# | cafe::1 | encap seg6 mode encap segs fc00::100 | +# +---------+---------------------------------------+ +# +# ns_router: post-encap SID resolution +# +-------+------------+----------------------------+ +# | table | dst | action | +# +-------+------------+----------------------------+ +# | 100 | fc00::100 | via fd01::2 dev veth-r1 | +# +-------+------------+----------------------------+ +# | main | fc00::100 | blackhole | +# +-------+------------+----------------------------+ +# +# ns_router: ip rule +# +------------------+------------------------------+ +# | match | action | +# +------------------+------------------------------+ +# | iif veth-r0 | lookup 100 | +# +------------------+------------------------------+ +# +# ns_dst: SRv6 decap (main table) +# +--------------+----------------------------------+ +# | SID | action | +# +--------------+----------------------------------+ +# | fc00::100 | End.DT6 table 255 (local) | +# +--------------+----------------------------------+ + +source lib.sh + +readonly SID="fc00::100" +readonly DEST="cafe::1" + +readonly SRC_MAC="02:00:00:00:00:01" +readonly RTR_R0_MAC="02:00:00:00:00:02" +readonly RTR_R1_MAC="02:00:00:00:00:03" +readonly DST_MAC="02:00:00:00:00:04" + +cleanup() +{ + cleanup_ns "${NS_SRC}" "${NS_RTR}" "${NS_DST}" +} + +check_prerequisites() +{ + if ! command -v ip &>/dev/null; then + echo "SKIP: ip tool not found" + exit "${ksft_skip}" + fi + + if ! command -v ping &>/dev/null; then + echo "SKIP: ping not found" + exit "${ksft_skip}" + fi + + if ! command -v sysctl &>/dev/null; then + echo "SKIP: sysctl not found" + exit "${ksft_skip}" + fi + + if ! command -v taskset &>/dev/null; then + echo "SKIP: taskset not found" + exit "${ksft_skip}" + fi +} + +setup() +{ + setup_ns NS_SRC NS_RTR NS_DST + + ip link add veth-s0 netns "${NS_SRC}" type veth \ + peer name veth-r0 netns "${NS_RTR}" + ip link add veth-r1 netns "${NS_RTR}" type veth \ + peer name veth-d0 netns "${NS_DST}" + + ip -n "${NS_SRC}" link set veth-s0 address "${SRC_MAC}" + ip -n "${NS_RTR}" link set veth-r0 address "${RTR_R0_MAC}" + ip -n "${NS_RTR}" link set veth-r1 address "${RTR_R1_MAC}" + ip -n "${NS_DST}" link set veth-d0 address "${DST_MAC}" + + # ns_src + ip -n "${NS_SRC}" link set veth-s0 up + ip -n "${NS_SRC}" addr add fd00::1/64 dev veth-s0 nodad + ip -n "${NS_SRC}" -6 route add "${DEST}"/128 via fd00::2 + + # ns_router + ip -n "${NS_RTR}" link set veth-r0 up + ip -n "${NS_RTR}" addr add fd00::2/64 dev veth-r0 nodad + ip -n "${NS_RTR}" link set veth-r1 up + ip -n "${NS_RTR}" addr add fd01::1/64 dev veth-r1 nodad + ip netns exec "${NS_RTR}" sysctl -qw net.ipv6.conf.all.forwarding=1 + + ip -n "${NS_RTR}" -6 route add "${DEST}"/128 \ + encap seg6 mode encap segs "${SID}" dev veth-r0 + ip -n "${NS_RTR}" -6 route add "${SID}"/128 table 100 \ + via fd01::2 dev veth-r1 + ip -n "${NS_RTR}" -6 route add blackhole "${SID}"/128 + ip -n "${NS_RTR}" -6 rule add iif veth-r0 lookup 100 + + # ns_dst + ip -n "${NS_DST}" link set veth-d0 up + ip -n "${NS_DST}" addr add fd01::2/64 dev veth-d0 nodad + ip -n "${NS_DST}" addr add "${DEST}"/128 dev lo nodad + ip -n "${NS_DST}" -6 route add "${SID}"/128 \ + encap seg6local action End.DT6 table 255 dev veth-d0 + ip -n "${NS_DST}" -6 route add fd00::/64 via fd01::1 + + # static neighbors + ip -n "${NS_SRC}" -6 neigh add fd00::2 dev veth-s0 \ + lladdr "${RTR_R0_MAC}" nud permanent + ip -n "${NS_RTR}" -6 neigh add fd00::1 dev veth-r0 \ + lladdr "${SRC_MAC}" nud permanent + ip -n "${NS_RTR}" -6 neigh add fd01::2 dev veth-r1 \ + lladdr "${DST_MAC}" nud permanent + ip -n "${NS_DST}" -6 neigh add fd01::1 dev veth-d0 \ + lladdr "${RTR_R1_MAC}" nud permanent +} + +test_cache_isolation() +{ + RET=0 + + # local ping with empty cache: must fail (SID is blackholed) + if ip netns exec "${NS_RTR}" taskset -c 0 \ + ping -c 1 -W 2 "${DEST}" &>/dev/null; then + echo "SKIP: local ping succeeded, topology broken" + exit "${ksft_skip}" + fi + + # forward from ns_src to populate the input cache + if ! ip netns exec "${NS_SRC}" taskset -c 0 \ + ping -c 1 -W 2 "${DEST}" &>/dev/null; then + echo "SKIP: forwarded ping failed, topology broken" + exit "${ksft_skip}" + fi + + # local ping again: must still fail; if the output path reuses + # the input cache, it bypasses the blackhole and the ping succeeds + if ip netns exec "${NS_RTR}" taskset -c 0 \ + ping -c 1 -W 2 "${DEST}" &>/dev/null; then + echo "FAIL: output path used dst cached by input path" + RET="${ksft_fail}" + else + echo "PASS: output path dst_cache is independent" + fi + + return "${RET}" +} + +if [ "$(id -u)" -ne 0 ]; then + echo "SKIP: Need root privileges" + exit "${ksft_skip}" +fi + +trap cleanup EXIT + +check_prerequisites +setup +test_cache_isolation +exit "${RET}" |