ipconfig: BOOTP: Don't request IEN-116 name servers
authorChris Novakovic <chris@chrisn.me.uk>
Tue, 24 Apr 2018 02:56:34 +0000 (03:56 +0100)
committerDavid S. Miller <davem@davemloft.net>
Tue, 24 Apr 2018 17:40:41 +0000 (13:40 -0400)
commit4e1a8af28d56a4194cf3f17c69d9d21183246f3a
tree350e6a77f4766b144e6154b7b30789d34769a7ed
parente18bdc83aec4b7e187d9c54dc442a6ab3efac26d
ipconfig: BOOTP: Don't request IEN-116 name servers

When ipconfig is autoconfigured via BOOTP, the request packet
initialised by ic_bootp_init_ext() allocates 8 bytes for tag 5 ("Name
Server" [1, §3.7]), but tag 5 in the response isn't processed by
ic_do_bootp_ext(). Instead, allocate the 8 bytes to tag 6 ("Domain Name
Server" [1, §3.8]), which is processed by ic_do_bootp_ext(), and appears
to have been the intended tag to request.

This won't cause any breakage for existing users, as tag 5 responses
provided by BOOTP servers weren't being processed anyway.

[1] RFC 2132, "DHCP Options and BOOTP Vendor Extensions":
    https://tools.ietf.org/rfc/rfc2132.txt

Signed-off-by: Chris Novakovic <chris@chrisn.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/ipconfig.c