[Pkg-utopia-maintainers] Bug#392813: dns completely failed after upgrade to libnss-mdns 0.8-5

[Walter Hofmann]

Package: libnss-mdns
Version: 0.8-5
Severity: normal

After today's Sid dist-upgrade, programs couldn't resolve names anymore.
E.g. "ping www.google.com" fails with "ping: unknown host www.google.com".
An strace of the failing ping is below.

I have never used libnss-mdns, but it was upgraded during the last
dist-upgrade so it is suspect. I'm not sure why it is installed at all,
I certainly never used it. I see that there is the following entry in
/etc/nsswitch.conf:
 hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4
changing this entry to
 hosts:          files dns
made things work again.


# strace ping www.google.com
[...]
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 4
setsockopt(4, SOL_IP, IP_MULTICAST_TTL, [255], 4) = 0
bind(4, {sa_family=AF_INET, sin_port=htons(0),
sin_addr=inet_addr("0.0.0.0")}, 16) = 0
setsockopt(4, SOL_IP, IP_RECVTTL, [1], 4) = 0
setsockopt(4, SOL_IP, IP_PKTINFO, [1], 4) = 0
fcntl64(4, F_GETFD)                     = 0
fcntl64(4, F_SETFD, FD_CLOEXEC)         = 0
fcntl64(4, F_GETFL)                     = 0x2 (flags O_RDWR)
fcntl64(4, F_SETFL, O_RDWR|O_NONBLOCK)  = 0
open("/etc/resolv.conf", O_RDONLY)      = 5
fstat64(5, {st_mode=S_IFREG|0644, st_size=34, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
0) = 0xb7f6f000
read(5, "search local\nnameserver 127.0.0."..., 4096) = 34
read(5, "", 4096)                       = 0
close(5)                                = 0
munmap(0xb7f6f000, 4096)                = 0
open("/dev/urandom", O_RDONLY)          = 5
read(5, "\377\31", 2)                   = 2
close(5)                                = 0
ioctl(4, SIOCGIFCONF, {192, {{"lo", {AF_INET, inet_addr("127.0.0.1")}},
{"eth0", {AF_INET, inet_addr("192.168.4.1")}}, {"wlan0", {AF_INET,
inet_addr("192.168.1.1")}}, {"vmnet1", {AF_INET,
inet_addr("172.16.160.1")}}, {"vmnet8", {AF_INET,
inet_addr("192.168.215.1")}}, {"ppp0", {AF_INET,
inet_addr("84.57.79.55")}}}}) = 0
ioctl(4, SIOCGIFFLAGS, {ifr_name="eth0",
ifr_flags=IFF_UP|IFF_BROADCAST|IFF_MULTICAST}) = 0
ioctl(4, SIOCGIFFLAGS, {ifr_name="wlan0",
ifr_flags=IFF_UP|IFF_BROADCAST|IFF_RUNNING|IFF_MULTICAST}) = 0
ioctl(4, SIOCGIFINDEX, {ifr_name="wlan0", ifr_index=3}) = 0
sendmsg(4, {msg_name(16)={sa_family=AF_INET, sin_port=htons(5353),
sin_addr=inet_addr("224.0.0.251")},
msg_iov(1)=[{"\31\377\0\0\0\1\0\0\0\0\0\0\3www\6google\3com\5loca"...,
38}], msg_controllen=24, {cmsg_len=24, cmsg_level=SOL_IP, cmsg_type=,
...}, msg_flags=0}, MSG_DONTROUTE) = -1
EPERM (Operation not permitted)
close(4)                                = 0
write(2, "ping: unknown host www.google.co"..., 34ping: unknown host
www.google.com
) = 34
exit_group(2)                           = ?
Process 30762 detached
#






-- System Information:
Debian Release: testing/unstable
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable'), (1, 'experimental')
Architecture: i386 (i686)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.6.16.11
Locale: LANG=de_DE at euro, LC_CTYPE=de_DE at euro (charmap=ISO-8859-15) (ignored: LC_ALL set to de_DE at euro)

Versions of packages libnss-mdns depends on:
ii  base-files                   3.1.16      Debian base system miscellaneous f
ii  libc6                        2.3.6.ds1-6 GNU C Library: Shared libraries

libnss-mdns recommends no packages.

-- no debconf information