Resolves: #2168855 - BFD not working through VRF
This commit is contained in:
Michal Ruprich
parent
afb66bcb7e
commit
4fbe36d12f
255
0012-bfd-not-working-in-vrf.patch
Normal file
255
0012-bfd-not-working-in-vrf.patch
Normal file
@ -0,0 +1,255 @@
|
||||
From edc3f63167fd95e4e70287743c9b252415c9336e Mon Sep 17 00:00:00 2001
|
||||
From: Philippe Guibert <philippe.guibert@6wind.com>
|
||||
Date: Thu, 7 Jul 2022 14:33:48 +0200
|
||||
Subject: [PATCH] bfdd: allow l3vrf bfd sessions without udp leaking
|
||||
|
||||
Until now, when in vrf-lite mode, the BFD implementation
|
||||
creates a single UDP socket and relies on the following
|
||||
sysctl value to 1:
|
||||
|
||||
echo 1 > /proc/sys/net/ipv4/udp_l3mdev_accept
|
||||
|
||||
With this setting, the incoming BFD packets from a given
|
||||
vrf, would leak to the default vrf, and would match the
|
||||
UDP socket.
|
||||
|
||||
The drawback of this solution is that udp packets received
|
||||
on a given vrf may leak to an other vrf. This may be a
|
||||
security concern.
|
||||
|
||||
The commit addresses this issue by avoiding this leak
|
||||
mechanism. An UDP socket is created for each vrf, and each
|
||||
socket uses new setsockopt option: SO_REUSEADDR + SO_REUSEPORT.
|
||||
|
||||
With this option, the incoming UDP packets are distributed on
|
||||
the available sockets. The impact of those options with l3mdev
|
||||
devices is unknown. It has been observed that this option is not
|
||||
needed, until the default vrf sockets are created.
|
||||
|
||||
To ensure the BFD packets are correctly routed to the appropriate
|
||||
socket, a BPF filter has been put in place and attached to the
|
||||
sockets : SO_ATTACH_REUSEPORT_CBPF. This option adds a criterium
|
||||
to force the packet to choose a given socket. If initial criteria
|
||||
from the default distribution algorithm were not good, at least
|
||||
two sockets would be available, and the CBPF would force the
|
||||
selection to the same socket. This would come to the situation
|
||||
where an incoming packet would be processed on a different vrf.
|
||||
|
||||
The bpf code is the following one:
|
||||
|
||||
struct sock_filter code[] = {
|
||||
{ BPF_RET | BPF_K, 0, 0, 0 },
|
||||
};
|
||||
|
||||
struct sock_fprog p = {
|
||||
.len = sizeof(code)/sizeof(struct sock_filter),
|
||||
.filter = code,
|
||||
};
|
||||
|
||||
if (setsockopt(sd, SOL_SOCKET, SO_ATTACH_REUSEPORT_CBPF, &p, sizeof(p))) {
|
||||
zlog_warn("unable to set SO_ATTACH_REUSEPORT_CBPF on socket: %s",
|
||||
strerror(errno));
|
||||
return -1;
|
||||
}
|
||||
|
||||
Some tests have been done with by creating vrf contexts, and by using
|
||||
the below vtysh configuration:
|
||||
|
||||
ip route 2.2.2.2/32 10.126.0.2
|
||||
vrf vrf2
|
||||
ip route 2.2.2.2/32 10.126.0.2
|
||||
!
|
||||
interface ntfp2
|
||||
ip address 10.126.0.1/24
|
||||
!
|
||||
interface ntfp3 vrf vrf4
|
||||
ip address 10.126.0.1/24
|
||||
!
|
||||
interface ntfp2 vrf vrf1
|
||||
ip address 10.126.0.1/24
|
||||
!
|
||||
interface ntfp2.100 vrf vrf2
|
||||
ip address 10.126.0.1/24
|
||||
!
|
||||
interface ntfp2.200 vrf vrf3
|
||||
ip address 10.126.0.1/24
|
||||
!
|
||||
line vty
|
||||
!
|
||||
bfd
|
||||
peer 10.126.0.2 vrf vrf2
|
||||
!
|
||||
peer 10.126.0.2 vrf vrf3
|
||||
!
|
||||
peer 10.126.0.2
|
||||
!
|
||||
peer 10.126.0.2 vrf vrf4
|
||||
!
|
||||
peer 2.2.2.2 multihop local-address 1.1.1.1
|
||||
!
|
||||
peer 2.2.2.2 multihop local-address 1.1.1.1 vrf vrf2
|
||||
transmit-interval 1500
|
||||
receive-interval 1500
|
||||
!
|
||||
|
||||
The results showed no issue related to packets received by
|
||||
the wrong vrf. Even changing the udp_l3mdev_accept flag to
|
||||
1 did not change the test results.
|
||||
|
||||
Signed-off-by: Philippe Guibert <philippe.guibert@6wind.com>
|
||||
---
|
||||
bfdd/bfd.c | 66 +++++++++++++++++++++++------------------------
|
||||
bfdd/bfd_packet.c | 45 ++++++++++++++++++++++++++++++++
|
||||
2 files changed, 77 insertions(+), 34 deletions(-)
|
||||
|
||||
diff --git a/bfdd/bfd.c b/bfdd/bfd.c
|
||||
index 483beb1b17c..a1619263588 100644
|
||||
--- a/bfdd/bfd.c
|
||||
+++ b/bfdd/bfd.c
|
||||
@@ -1950,40 +1950,38 @@ static int bfd_vrf_enable(struct vrf *vrf)
|
||||
if (bglobal.debug_zebra)
|
||||
zlog_debug("VRF enable add %s id %u", vrf->name, vrf->vrf_id);
|
||||
|
||||
- if (vrf->vrf_id == VRF_DEFAULT ||
|
||||
- vrf_get_backend() == VRF_BACKEND_NETNS) {
|
||||
- if (!bvrf->bg_shop)
|
||||
- bvrf->bg_shop = bp_udp_shop(vrf);
|
||||
- if (!bvrf->bg_mhop)
|
||||
- bvrf->bg_mhop = bp_udp_mhop(vrf);
|
||||
- if (!bvrf->bg_shop6)
|
||||
- bvrf->bg_shop6 = bp_udp6_shop(vrf);
|
||||
- if (!bvrf->bg_mhop6)
|
||||
- bvrf->bg_mhop6 = bp_udp6_mhop(vrf);
|
||||
- if (!bvrf->bg_echo)
|
||||
- bvrf->bg_echo = bp_echo_socket(vrf);
|
||||
- if (!bvrf->bg_echov6)
|
||||
- bvrf->bg_echov6 = bp_echov6_socket(vrf);
|
||||
-
|
||||
- if (!bvrf->bg_ev[0] && bvrf->bg_shop != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_shop, &bvrf->bg_ev[0]);
|
||||
- if (!bvrf->bg_ev[1] && bvrf->bg_mhop != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_mhop, &bvrf->bg_ev[1]);
|
||||
- if (!bvrf->bg_ev[2] && bvrf->bg_shop6 != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_shop6, &bvrf->bg_ev[2]);
|
||||
- if (!bvrf->bg_ev[3] && bvrf->bg_mhop6 != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_mhop6, &bvrf->bg_ev[3]);
|
||||
- if (!bvrf->bg_ev[4] && bvrf->bg_echo != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_echo, &bvrf->bg_ev[4]);
|
||||
- if (!bvrf->bg_ev[5] && bvrf->bg_echov6 != -1)
|
||||
- thread_add_read(master, bfd_recv_cb, bvrf,
|
||||
- bvrf->bg_echov6, &bvrf->bg_ev[5]);
|
||||
- }
|
||||
+ if (!bvrf->bg_shop)
|
||||
+ bvrf->bg_shop = bp_udp_shop(vrf);
|
||||
+ if (!bvrf->bg_mhop)
|
||||
+ bvrf->bg_mhop = bp_udp_mhop(vrf);
|
||||
+ if (!bvrf->bg_shop6)
|
||||
+ bvrf->bg_shop6 = bp_udp6_shop(vrf);
|
||||
+ if (!bvrf->bg_mhop6)
|
||||
+ bvrf->bg_mhop6 = bp_udp6_mhop(vrf);
|
||||
+ if (!bvrf->bg_echo)
|
||||
+ bvrf->bg_echo = bp_echo_socket(vrf);
|
||||
+ if (!bvrf->bg_echov6)
|
||||
+ bvrf->bg_echov6 = bp_echov6_socket(vrf);
|
||||
+
|
||||
+ if (!bvrf->bg_ev[0] && bvrf->bg_shop != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_shop,
|
||||
+ &bvrf->bg_ev[0]);
|
||||
+ if (!bvrf->bg_ev[1] && bvrf->bg_mhop != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_mhop,
|
||||
+ &bvrf->bg_ev[1]);
|
||||
+ if (!bvrf->bg_ev[2] && bvrf->bg_shop6 != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_shop6,
|
||||
+ &bvrf->bg_ev[2]);
|
||||
+ if (!bvrf->bg_ev[3] && bvrf->bg_mhop6 != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_mhop6,
|
||||
+ &bvrf->bg_ev[3]);
|
||||
+ if (!bvrf->bg_ev[4] && bvrf->bg_echo != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_echo,
|
||||
+ &bvrf->bg_ev[4]);
|
||||
+ if (!bvrf->bg_ev[5] && bvrf->bg_echov6 != -1)
|
||||
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_echov6,
|
||||
+ &bvrf->bg_ev[5]);
|
||||
+
|
||||
if (vrf->vrf_id != VRF_DEFAULT) {
|
||||
bfdd_zclient_register(vrf->vrf_id);
|
||||
bfdd_sessions_enable_vrf(vrf);
|
||||
diff --git a/bfdd/bfd_packet.c b/bfdd/bfd_packet.c
|
||||
index d34d6427628..054a9bfbf21 100644
|
||||
--- a/bfdd/bfd_packet.c
|
||||
+++ b/bfdd/bfd_packet.c
|
||||
@@ -876,6 +876,14 @@ void bfd_recv_cb(struct thread *t)
|
||||
"no session found");
|
||||
return;
|
||||
}
|
||||
+ /*
|
||||
+ * We may have a situation where received packet is on wrong vrf
|
||||
+ */
|
||||
+ if (bfd && bfd->vrf && bfd->vrf != bvrf->vrf) {
|
||||
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
|
||||
+ "wrong vrfid.");
|
||||
+ return;
|
||||
+ }
|
||||
|
||||
/* Ensure that existing good sessions are not overridden. */
|
||||
if (!cp->discrs.remote_discr && bfd->ses_state != PTM_BFD_DOWN &&
|
||||
@@ -1208,10 +1216,41 @@ int bp_set_tos(int sd, uint8_t value)
|
||||
return 0;
|
||||
}
|
||||
|
||||
+static bool bp_set_reuse_addr(int sd)
|
||||
+{
|
||||
+ int one = 1;
|
||||
+
|
||||
+ if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) == -1) {
|
||||
+ zlog_warn("set-reuse-addr: setsockopt(SO_REUSEADDR, %d): %s",
|
||||
+ one, strerror(errno));
|
||||
+ return false;
|
||||
+ }
|
||||
+ return true;
|
||||
+}
|
||||
+
|
||||
+static bool bp_set_reuse_port(int sd)
|
||||
+{
|
||||
+ int one = 1;
|
||||
+
|
||||
+ if (setsockopt(sd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) == -1) {
|
||||
+ zlog_warn("set-reuse-port: setsockopt(SO_REUSEPORT, %d): %s",
|
||||
+ one, strerror(errno));
|
||||
+ return false;
|
||||
+ }
|
||||
+ return true;
|
||||
+}
|
||||
+
|
||||
+
|
||||
static void bp_set_ipopts(int sd)
|
||||
{
|
||||
int rcvttl = BFD_RCV_TTL_VAL;
|
||||
|
||||
+ if (!bp_set_reuse_addr(sd))
|
||||
+ zlog_fatal("set-reuse-addr: failed");
|
||||
+
|
||||
+ if (!bp_set_reuse_port(sd))
|
||||
+ zlog_fatal("set-reuse-port: failed");
|
||||
+
|
||||
if (bp_set_ttl(sd, BFD_TTL_VAL) != 0)
|
||||
zlog_fatal("set-ipopts: TTL configuration failed");
|
||||
|
||||
@@ -1453,6 +1492,12 @@ static void bp_set_ipv6opts(int sd)
|
||||
int ipv6_pktinfo = BFD_IPV6_PKT_INFO_VAL;
|
||||
int ipv6_only = BFD_IPV6_ONLY_VAL;
|
||||
|
||||
+ if (!bp_set_reuse_addr(sd))
|
||||
+ zlog_fatal("set-reuse-addr: failed");
|
||||
+
|
||||
+ if (!bp_set_reuse_port(sd))
|
||||
+ zlog_fatal("set-reuse-port: failed");
|
||||
+
|
||||
if (bp_set_ttlv6(sd, BFD_TTL_VAL) == -1)
|
||||
zlog_fatal(
|
||||
"set-ipv6opts: setsockopt(IPV6_UNICAST_HOPS, %d): %s",
|
||||
6
frr.spec
6
frr.spec
@ -7,7 +7,7 @@
|
||||
|
||||
Name: frr
|
||||
Version: 8.3.1
|
||||
Release: 6%{?checkout}%{?dist}
|
||||
Release: 7%{?checkout}%{?dist}
|
||||
Summary: Routing daemon
|
||||
License: GPLv2+
|
||||
URL: http://www.frrouting.org
|
||||
@ -74,6 +74,7 @@ Patch0008: 0008-frr-non-root-user.patch
|
||||
Patch0009: 0009-CVE-2022-36440-40302.patch
|
||||
Patch0010: 0010-CVE-2022-43681.patch
|
||||
Patch0011: 0011-CVE-2022-40318.patch
|
||||
Patch0012: 0012-bfd-not-working-in-vrf.patch
|
||||
|
||||
%description
|
||||
FRRouting is free software that manages TCP/IP based routing protocols. It takes
|
||||
@ -279,6 +280,9 @@ make check PYTHON=%{__python3}
|
||||
%endif
|
||||
|
||||
%changelog
|
||||
* Wed Jun 07 2023 Michal Ruprich <mruprich@redhat.com> - 8.3.1-7
|
||||
- Resolves: #2168855 - BFD not working through VRF
|
||||
|
||||
* Tue May 23 2023 Michal Ruprich <mruprich@redhat.com> - 8.3.1-6
|
||||
- Resolves: #2184870 - Reachable assertion in peek_for_as4_capability function
|
||||
- Resolves: #2196795 - denial of service by crafting a BGP OPEN message with an option of type 0xff
|
||||
|
||||
Loading…
Reference in New Issue
Block a user