"Failed to convert source address to presentation format" when using a specified interface that has both IPv4 and IPv6 addresses #2206
Description
Describe the bug
When I try to discover hosts that are not reachable from a specific interface, and the interface has both IPv4 and IPv6 addresses, nmap fails with:
Failed to convert source address to presentation format!?! Error: Address family not supported by protocol
QUITTING!
Moreover, if the argument is a list of IP addresses (some of them reachable), none of those hosts will be discovered because of the error.
To Reproduce
I'm including a script that reproduces the behavior with Docker CE (20.10.0 on Fedora 32 in my case).
Important: Make sure Docker assigns IPv4 addresses to the interfaces.
#!/bin/bash
DOCKER_IMAGE=docker.io/instrumentisto/nmap
echo ">>> Create two IPv6 networks"
docker network create --ipv6 --subnet 2001:db8::/120 ipv6-net-1
docker network create --ipv6 --subnet fe80:5054::/120 ipv6-net-2
echo
echo ">>> Run container #1 attached to the networks so it has two NICs"
CONTAINER_1=`docker run -d --entrypoint sleep --net ipv6-net-1 $DOCKER_IMAGE 600`
docker network connect ipv6-net-2 $CONTAINER_1
docker exec -ti $CONTAINER_1 ip a
echo
echo ">>> Run container #2 attached to the networks"
CONTAINER_2=`docker run -d --entrypoint sleep --net ipv6-net-1 $DOCKER_IMAGE 600`
docker network connect ipv6-net-2 $CONTAINER_2
docker exec -ti $CONTAINER_2 ip a
echo
echo ">>> Run NMAP from eth0 to the two addresses of container #1"
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth0 2001:db8::2 fe80:5054::2
echo
echo ">>> Run NMAP from eth1 to the two addresses of container #1"
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth1 2001:db8::2 fe80:5054::2
echo
echo ">>> Now run NMAP from eth0 and then eth1, but for each address individually"
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth0 2001:db8::2
echo
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth0 fe80:5054::2
echo
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth1 2001:db8::2
echo
docker exec -ti $CONTAINER_2 nmap -6 -sn -n -e eth1 fe80:5054::2
echo
echo ">>> Cleanup"
docker kill $CONTAINER_1 $CONTAINER_2
docker rm $CONTAINER_1 $CONTAINER_2
docker network rm ipv6-net-1 ipv6-net-2Expected behavior
A standard message saying that the host is down, or at least some hosts discovered in case of multiple IP addresses.
Version info (please complete the following information):
- OS: Alpine Linux v3.12 (containerized)
- Output of
nmap --version:
Nmap version 7.91 ( https://nmap.org )
Platform: x86_64-unknown-linux-gnu
Compiled with: nmap-liblua-5.3.5 openssl-3.1.2 nmap-libssh2-1.9.0 nmap-libz-1.2.11 nmap-libpcre-7.6 libpcap-1.9.1 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: epoll poll select
- Output of
nmap --iflist
Starting Nmap 7.91 ( https://nmap.org ) at 2020-12-16 16:43 UTC
************************INTERFACES************************
DEV (SHORT) IP/MASK TYPE UP MTU MAC
lo (lo) 127.0.0.1/8 loopback up 65536
lo (lo) ::1/128 loopback up 65536
eth0 (eth0) 172.22.0.3/16 ethernet up 1500 02:42:AC:16:00:03
eth0 (eth0) 2001:db8::3/120 ethernet up 1500 02:42:AC:16:00:03
eth0 (eth0) fe80::42:acff:fe16:3/64 ethernet up 1500 02:42:AC:16:00:03
eth1 (eth1) 172.23.0.3/16 ethernet up 1500 02:42:AC:17:00:03
eth1 (eth1) fe80::42:acff:fe17:3/64 ethernet up 1500 02:42:AC:17:00:03
eth1 (eth1) fe80:5054::3/120 ethernet up 1500 02:42:AC:17:00:03
**************************ROUTES**************************
DST/MASK DEV METRIC GATEWAY
172.23.0.0/16 eth1 0
172.22.0.0/16 eth0 0
0.0.0.0/0 eth0 0 172.22.0.1
fe80:5054::3/128 eth1 0
::1/128 lo 0
2001:db8::3/128 eth0 0
2001:db8::/120 eth0 256
fe80:5054::/120 eth1 256
fe80::/64 eth0 256
fe80::/64 eth1 256
ff00::/8 eth0 256
ff00::/8 eth1 256
::/0 eth0 1024 2001:db8::1
Additional context
I observed this problem with a variety of OSs (containers) and nmap versions.