linux/net
Francesco Ruggeri fac6fce9bd net: icmp6: provide input address for traceroute6
traceroute6 output can be confusing, in that it shows the address
that a router would use to reach the sender, rather than the address
the packet used to reach the router.
Consider this case:

        ------------------------ N2
         |                    |
       ------              ------  N3  ----
       | R1 |              | R2 |------|H2|
       ------              ------      ----
         |                    |
        ------------------------ N1
                  |
                 ----
                 |H1|
                 ----

where H1's default route is through R1, and R1's default route is
through R2 over N2.
traceroute6 from H1 to H2 shows R2's address on N1 rather than on N2.

The script below can be used to reproduce this scenario.

traceroute6 output without this patch:

traceroute to 2000:103::4 (2000:103::4), 30 hops max, 80 byte packets
 1  2000:101::1 (2000:101::1)  0.036 ms  0.008 ms  0.006 ms
 2  2000:101::2 (2000:101::2)  0.011 ms  0.008 ms  0.007 ms
 3  2000:103::4 (2000:103::4)  0.013 ms  0.010 ms  0.009 ms

traceroute6 output with this patch:

traceroute to 2000:103::4 (2000:103::4), 30 hops max, 80 byte packets
 1  2000:101::1 (2000:101::1)  0.056 ms  0.019 ms  0.006 ms
 2  2000:102::2 (2000:102::2)  0.013 ms  0.008 ms  0.008 ms
 3  2000:103::4 (2000:103::4)  0.013 ms  0.009 ms  0.009 ms

#!/bin/bash
#
#        ------------------------ N2
#         |                    |
#       ------              ------  N3  ----
#       | R1 |              | R2 |------|H2|
#       ------              ------      ----
#         |                    |
#        ------------------------ N1
#                  |
#                 ----
#                 |H1|
#                 ----
#
# N1: 2000:101::/64
# N2: 2000:102::/64
# N3: 2000:103::/64
#
# R1's host part of address: 1
# R2's host part of address: 2
# H1's host part of address: 3
# H2's host part of address: 4
#
# For example:
# the IPv6 address of R1's interface on N2 is 2000:102::1/64
#
# Nets are implemented by macvlan interfaces (bridge mode) over
# dummy interfaces.
#

# Create net namespaces
ip netns add host1
ip netns add host2
ip netns add rtr1
ip netns add rtr2

# Create nets
ip link add net1 type dummy; ip link set net1 up
ip link add net2 type dummy; ip link set net2 up
ip link add net3 type dummy; ip link set net3 up

# Add interfaces to net1, move them to their nemaspaces
ip link add link net1 dev host1net1 type macvlan mode bridge
ip link set host1net1 netns host1
ip link add link net1 dev rtr1net1 type macvlan mode bridge
ip link set rtr1net1 netns rtr1
ip link add link net1 dev rtr2net1 type macvlan mode bridge
ip link set rtr2net1 netns rtr2

# Add interfaces to net2, move them to their nemaspaces
ip link add link net2 dev rtr1net2 type macvlan mode bridge
ip link set rtr1net2 netns rtr1
ip link add link net2 dev rtr2net2 type macvlan mode bridge
ip link set rtr2net2 netns rtr2

# Add interfaces to net3, move them to their nemaspaces
ip link add link net3 dev rtr2net3 type macvlan mode bridge
ip link set rtr2net3 netns rtr2
ip link add link net3 dev host2net3 type macvlan mode bridge
ip link set host2net3 netns host2

# Configure interfaces and routes in host1
ip netns exec host1 ip link set lo up
ip netns exec host1 ip link set host1net1 up
ip netns exec host1 ip -6 addr add 2000:101::3/64 dev host1net1
ip netns exec host1 ip -6 route add default via 2000:101::1

# Configure interfaces and routes in rtr1
ip netns exec rtr1 ip link set lo up
ip netns exec rtr1 ip link set rtr1net1 up
ip netns exec rtr1 ip -6 addr add 2000:101::1/64 dev rtr1net1
ip netns exec rtr1 ip link set rtr1net2 up
ip netns exec rtr1 ip -6 addr add 2000:102::1/64 dev rtr1net2
ip netns exec rtr1 ip -6 route add default via 2000:102::2
ip netns exec rtr1 sysctl net.ipv6.conf.all.forwarding=1

# Configure interfaces and routes in rtr2
ip netns exec rtr2 ip link set lo up
ip netns exec rtr2 ip link set rtr2net1 up
ip netns exec rtr2 ip -6 addr add 2000:101::2/64 dev rtr2net1
ip netns exec rtr2 ip link set rtr2net2 up
ip netns exec rtr2 ip -6 addr add 2000:102::2/64 dev rtr2net2
ip netns exec rtr2 ip link set rtr2net3 up
ip netns exec rtr2 ip -6 addr add 2000:103::2/64 dev rtr2net3
ip netns exec rtr2 sysctl net.ipv6.conf.all.forwarding=1

# Configure interfaces and routes in host2
ip netns exec host2 ip link set lo up
ip netns exec host2 ip link set host2net3 up
ip netns exec host2 ip -6 addr add 2000:103::4/64 dev host2net3
ip netns exec host2 ip -6 route add default via 2000:103::2

# Ping host2 from host1
ip netns exec host1 ping6 -c5 2000:103::4

# Traceroute host2 from host1
ip netns exec host1 traceroute6 2000:103::4

# Delete nets
ip link del net3
ip link del net2
ip link del net1

# Delete namespaces
ip netns del rtr2
ip netns del rtr1
ip netns del host2
ip netns del host1

Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Original-patch-by: Honggang Xu <hxu@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-03 17:26:53 -08:00
..
6lowpan 6lowpan: no need to check return value of debugfs_create functions 2019-07-06 12:50:01 +02:00
9p 9p pull request for inclusion in 5.4 2019-09-27 15:10:34 -07:00
802 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
8021q net: remove unnecessary variables and callback 2019-10-24 14:53:49 -07:00
appletalk appletalk: enforce CAP_NET_RAW for raw sockets 2019-09-24 16:37:18 +02:00
atm net: use skb_queue_empty_lockless() in poll() handlers 2019-10-28 13:33:41 -07:00
ax25 ax25: enforce CAP_NET_RAW for raw sockets 2019-09-24 16:37:18 +02:00
batman-adv Here are two batman-adv bugfixes: 2019-10-28 16:39:07 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
bpf bpf: Allow __sk_buff tstamp in BPF_PROG_TEST_RUN 2019-10-15 16:24:26 -07:00
bpfilter Kbuild updates for v5.3 2019-07-12 16:03:16 -07:00
bridge Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
can can: add support of SAE J1939 protocol 2019-09-04 14:22:33 +02:00
ceph libceph: use ceph_kvmalloc() for osdmap arrays 2019-09-16 12:06:25 +02:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
dcb treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
dccp inet: stop leaking jiffies on the wire 2019-11-01 14:57:52 -07:00
decnet net: use skb_queue_empty_lockless() in poll() handlers 2019-10-28 13:33:41 -07:00
dns_resolver Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
ethernet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 11:00:14 -07:00
hsr hsr: switch ->dellink() to ->ndo_uninit() 2019-07-11 14:37:45 -07:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
ife net: Fix Kconfig indentation 2019-09-26 08:56:17 +02:00
ipv4 net: icmp: use input address in traceroute 2019-11-03 17:25:18 -08:00
ipv6 net: icmp6: provide input address for traceroute6 2019-11-03 17:26:53 -08:00
iucv net/af_iucv: mark expected switch fall-throughs 2019-07-29 10:26:14 -07:00
kcm kcm: disable preemption in kcm_parse_func_strparser() 2019-09-27 10:27:14 +02:00
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
l2tp net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
l3mdev ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF 2019-06-23 13:24:17 -07:00
lapb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-17 20:20:36 -07:00
llc net: silence KCSAN warnings around sk_add_backlog() calls 2019-10-09 21:42:59 -07:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-20 10:43:00 -07:00
mac802154 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
mpls ipv4: mpls: fix mpls_xmit for iptunnel 2019-08-25 14:34:08 -07:00
ncsi net/ncsi: Disable global multicast filter 2019-09-19 18:04:40 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
netlabel netlabel: remove redundant assignment to pointer iter 2019-09-01 11:45:02 -07:00
netlink genetlink: do not parse attributes for families with zero maxattr 2019-10-13 11:20:03 -07:00
netrom net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
nsh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
openvswitch net: openvswitch: simplify the ovs_dp_cmd_new 2019-11-03 17:18:04 -08:00
packet netfilter: drop bridge nf reset from nf_reset 2019-10-01 18:42:15 +02:00
phonet net: use skb_queue_empty_lockless() in poll() handlers 2019-10-28 13:33:41 -07:00
psample net: sched: take reference to psample group in flow_action infra 2019-09-16 09:18:03 +02:00
qrtr net: qrtr: Simplify 'qrtr_tun_release()' 2019-10-30 17:58:23 -07:00
rds net/rds: Remove unnecessary null check 2019-10-17 15:23:03 -04:00
rfkill treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rose net: core: add generic lockdep keys 2019-10-24 14:53:48 -07:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
strparser Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
sunrpc SUNRPC: Destroy the back channel when we destroy the host transport 2019-10-30 12:04:35 -04:00
switchdev treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tipc tipc: improve message bundling algorithm 2019-11-03 17:26:15 -08:00
tls net/tls: store decrypted on a single bit 2019-10-07 09:58:28 -04:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
wimax wimax: no need to check return value of debugfs_create functions 2019-08-10 15:25:47 -07:00
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-02 13:54:56 -07:00
x25 net: silence KCSAN warnings around sk_add_backlog() calls 2019-10-09 21:42:59 -07:00
xdp Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2019-11-02 15:29:58 -07:00
xfrm netfilter: drop bridge nf reset from nf_reset 2019-10-01 18:42:15 +02:00
Kconfig devlink: Add packet trap infrastructure 2019-08-17 12:40:08 -07:00
Makefile
compat.c uio: make import_iovec()/compat_import_iovec() return bytes on success 2019-05-31 15:30:03 -06:00
socket.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
sysctl_net.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00