[pkg-dhcp-devel] Bug#629863: isc-dhcp-client: error dhcping means no routes are installed

[Sanjoy Mahajan]

Package: isc-dhcp-client
Version: 4.1.1-P1-17
Severity: grave
File: /sbin/dhclient-script

Today I noticed that ifup using dhcp kept failing, and I had to add the
routes manually.  The problem was in running dhclient, which would give
an error when executing the following shell command from
/sbin/dhclient-script:

  ip -4 addr add 192.168.101.18/255.255.255.0 broadcast 192.168.101.255 dev wlan0 label wlan0

The error was:

  Error: an inet prefix is expected rather than "192.168.101.18/255.255.255.0".

In the address, the information after the slash needs to be the number
of "1" bits in the netmask, rather than the netmask itself.  The
following hacky diff fixes it for me, but I doubt it's the best fix:

--- /sbin/dhclient-script	2011-05-19 02:13:42.000000000 -0400
+++ /sbin/dhclient-script	2011-06-08 19:17:00.000000000 -0400
@@ -140,6 +140,7 @@
 fi
 if [ -n "$new_subnet_mask" ]; then
     new_mask="/$new_subnet_mask"
+    new_mask_bits=`echo "$new_subnet_mask" | awk -F. '{print ($1+$2+$3+$4)/255*8;}'`
 fi
 if [ -n "$alias_subnet_mask" ]; then
     alias_mask="/$alias_subnet_mask"
@@ -209,7 +210,7 @@
            [ "$old_ip_address" != "$new_ip_address" ] ||
            [ "$reason" = "BOUND" ] || [ "$reason" = "REBOOT" ]; then
             # new IP has been leased or leased IP changed => set it
-            ip -4 addr add ${new_ip_address}${new_mask} ${new_broadcast_arg} \
+            ip -4 addr add ${new_ip_address}/${new_mask_bits} ${new_broadcast_arg} \
                 dev ${interface} label ${interface}
 
             if [ -n "$new_interface_mtu" ]; then


-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)

Kernel: Linux 2.6.38-2-686 (SMP w/2 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages isc-dhcp-client depends on:
ii  debianutils                  4           Miscellaneous utilities specific t
ii  iproute                      20110315-1  networking and traffic control too
ii  isc-dhcp-common              4.1.1-P1-17 common files used by all the isc-d
ii  libc6                        2.13-4      Embedded GNU C Library: Shared lib

isc-dhcp-client recommends no packages.

Versions of packages isc-dhcp-client suggests:
pn  avahi-autoipd                 <none>     (no description available)
pn  resolvconf                    <none>     (no description available)

-- Configuration Files:
/etc/dhcp/dhclient.conf changed:
supersede domain-name "mit.edu";
request subnet-mask, broadcast-address, time-offset, routers,
	domain-name, domain-name-servers, domain-search, host-name,
	netbios-name-servers, netbios-scope, interface-mtu;


-- debconf-show failed

-- 
-Sanjoy

`Until lions have their historians, tales of the hunt shall always
 glorify the hunters.'  --African Proverb