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>

diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index d0ea0ec..bcf3c4f 100644 (file)
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -721,7 +721,7 @@ static void __init ic_bootp_init_ext(u8 *e)
        *e++ = 3;               /* Default gateway request */
        *e++ = 4;
        e += 4;
-       *e++ = 5;               /* Name server request */
+       *e++ = 6;               /* (DNS) name server request */
        *e++ = 8;
        e += 8;
        *e++ = 12;              /* Host name request */