From d18c9a91979543adc182c7b28819691b64fda388 Mon Sep 17 00:00:00 2001 From: David Bright Date: Mon, 4 Oct 2021 08:43:41 -0700 Subject: [PATCH] RPCBIND: skip ipv6 link local when request is not from link local address RPCINFO on macOS behaves different compared to other linux clients and doesn't provide request address in rpcb structure of the RPCBPROC_GETADDRLIST call which doesn't seem to be forbidden. In this case RPCBIND uses RPC call's source address and picks a closest corresponding local address. If there are no addresses in the same subnet as the source address, return of RPCBIND may vary depending on the order of addresses returned in getifaddrs. If a link local precedes global address it may be returned even if the request comes from neither a link local nor from link local in a different scope, which will prevent services like nfs from working in tpc6 scenario on macOS clients. Issue can be seen only on FreeBSD rpcbind port due to changes in workflow of addrmerge call. Submitted by: Dmitry Ovsyannikov (Dmitry.Ovsyannikov@dell.com) Reviewers: dab Differential Revision: https://reviews.freebsd.org/D31491 Sponsored by: Dell EMC MFC to: stable/12, stable/13 MFC after: 1 week --- usr.sbin/rpcbind/tests/addrmerge_test.c | 34 +++++++++++++++++++++++++ usr.sbin/rpcbind/util.c | 12 +++++---- 2 files changed, 41 insertions(+), 5 deletions(-) diff --git a/usr.sbin/rpcbind/tests/addrmerge_test.c b/usr.sbin/rpcbind/tests/addrmerge_test.c index e1600f1a483..a29dc30fdde 100644 --- a/usr.sbin/rpcbind/tests/addrmerge_test.c +++ b/usr.sbin/rpcbind/tests/addrmerge_test.c @@ -257,6 +257,22 @@ mock_tun0(void) IFF_UP | IFF_RUNNING | IFF_POINTOPOINT | IFF_MULTICAST, 0, false); } +static void +mock_mlxen0(void) +{ + mock_ifaddr4("mlxen0", "192.0.3.1", "255.255.255.128", "192.0.3.127", + IFF_UP | IFF_BROADCAST | IFF_RUNNING | IFF_SIMPLEX | IFF_MULTICAST, + false); + /* Setting link local address before ipv6 address*/ + mock_ifaddr6("mlxen0", "fe80::4", "ffff:ffff:ffff:ffff::", + "fe80::ffff:ffff:ffff:ffff", + IFF_UP | IFF_BROADCAST | IFF_RUNNING | IFF_SIMPLEX | IFF_MULTICAST, + 3, false); + mock_ifaddr6("mlxen0", "2001:db8::7", "ffff:ffff:ffff:ffff::", + "2001:db8::ffff:ffff:ffff:ffff", + IFF_UP | IFF_BROADCAST | IFF_RUNNING | IFF_SIMPLEX | IFF_MULTICAST, + 0, false); +} /* Stub rpcbind functions */ int @@ -835,6 +851,23 @@ ATF_TC_BODY(addrmerge_recvdstaddr6_rev, tc) ATF_CHECK_STREQ("2001:db8::2.3.46", maddr); free(maddr); } + +ATF_TC_WITHOUT_HEAD(addrmerge_ipv6_other_subnet); +ATF_TC_BODY(addrmerge_ipv6_other_subnet, tc) +{ + char *maddr; + + /* getifaddrs will return link local before normal ipv6 */ + mock_lo0(); + mock_mlxen0(); + + maddr = do_addrmerge6("2001:db8:1::1.3.46"); + + /* We must return the closest ipv6 address*/ + ATF_REQUIRE(maddr != NULL); + ATF_CHECK_STREQ("2001:db8::7.3.46", maddr); + free(maddr); +} #endif /* INET6 */ @@ -864,6 +897,7 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, addrmerge_ipv6_linklocal_rev); ATF_TP_ADD_TC(tp, addrmerge_recvdstaddr6); ATF_TP_ADD_TC(tp, addrmerge_recvdstaddr6_rev); + ATF_TP_ADD_TC(tp, addrmerge_ipv6_other_subnet); #endif return (atf_no_error()); diff --git a/usr.sbin/rpcbind/util.c b/usr.sbin/rpcbind/util.c index 455578b657f..e497e922769 100644 --- a/usr.sbin/rpcbind/util.c +++ b/usr.sbin/rpcbind/util.c @@ -229,17 +229,19 @@ addrmerge(struct netbuf *caller, const char *serv_uaddr, const char *clnt_uaddr, * a link-local address then use the scope id to see * which one. */ - if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) && - IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && - IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) { - if (SA2SIN6(ifsa)->sin6_scope_id == - SA2SIN6(caller_sa)->sin6_scope_id) { + if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa))) { + if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) && + IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa)) && + (SA2SIN6(ifsa)->sin6_scope_id == + SA2SIN6(caller_sa)->sin6_scope_id)) { const int goodness = 3; if (bestif_goodness < goodness) { bestif = ifap; bestif_goodness = goodness; } + } else { + continue; } } } -- 2.45.0