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| author | Chris Novakovic <chris@chrisn.me.uk> | 2018-04-24 04:56:35 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-04-24 19:40:41 +0200 |
| commit | de1fa15b6642f0b66f1844b9b464a8c28e84347c (patch) | |
| tree | dffa5c3adf8ca466eb5e9fdea8a7016cabf50c47 | |
| parent | ipconfig: BOOTP: Don't request IEN-116 name servers (diff) | |
| download | linux-de1fa15b6642f0b66f1844b9b464a8c28e84347c.tar.xz linux-de1fa15b6642f0b66f1844b9b464a8c28e84347c.zip | |
ipconfig: BOOTP: Request CONF_NAMESERVERS_MAX name servers
When ipconfig is autoconfigured via BOOTP, the request packet
initialised by ic_bootp_init_ext() always allocates 8 bytes for the name
server option, limiting the BOOTP server to responding with at most 2
name servers even though ipconfig in fact supports an arbitrary number
of name servers (as defined by CONF_NAMESERVERS_MAX, which is currently
3).
Only request name servers in the request packet if CONF_NAMESERVERS_MAX
is positive (to comply with [1, ยง3.8]), and allocate enough space in the
packet for CONF_NAMESERVERS_MAX name servers to indicate the maximum
number we can accept in response.
[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>
| -rw-r--r-- | net/ipv4/ipconfig.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index bcf3c4f9882d..0f460d6d3cce 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -721,9 +721,11 @@ static void __init ic_bootp_init_ext(u8 *e) *e++ = 3; /* Default gateway request */ *e++ = 4; e += 4; +#if CONF_NAMESERVERS_MAX > 0 *e++ = 6; /* (DNS) name server request */ - *e++ = 8; - e += 8; + *e++ = 4 * CONF_NAMESERVERS_MAX; + e += 4 * CONF_NAMESERVERS_MAX; +#endif *e++ = 12; /* Host name request */ *e++ = 32; e += 32; |