Bug#421375: libc6: "No route to host" does not describe EHOSTUNREACH properly

[Bart Dopheide <dopheide@fmf.nl>]

Package: libc6
Version: 2.3.6.ds1-13
Severity: minor

IMHO "No route to host" is not a string that covers EHOSTUNREACH 
properly. In common situation it _is_ (that is why no one has complained 
so far I guess), but I run into trouble with ICMP type 3.13 (admin 
prohibited):

# iptables -I INPUT 1 -p tcp --dport 42 -j REJECT --reject-with icmp-admin-prohibited
# telnet localhost 42
Trying 127.0.0.1...
telnet: Unable to connect to remote host: No route to host

Clearly, there is a route to localhost, but perror describes 
EHOSTUNREACH as 'No route to host'. In real life situation, I run into 
trouble with access lists on (Cisco) routers. Testing the connection 
with telnet gives me nothing but a red herring; checking and rechecking 
every route tables on every router, traceroute-ing etc. and then 
discovering with tcpdump that is it in fact admin-prohibited.

Arguably, there is in fact no route, because the 'would-be route' is 
prohibited, but then I say that the host might be reachable on other 
ports, or with other protocols meaning that there _is_ a route

The only suggestion that comes to my mind that covers the charge better, 
is 'Destination unreachable'.

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)

Kernel: Linux 2.6.18-4-686 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libc6 depends on:
ii  tzdata                        2007e-3    Time Zone and Daylight Saving Time

libc6 recommends no packages.

-- no debconf information