busybox: Enable domain search list support in udhcpc
diff mbox series

Message ID 20190408110010.2596-1-abrodkin@synopsys.com
State Accepted
Commit 80291c3e9c591ee8cfb9262523cd5151ed0b747a
Headers show
Series
  • busybox: Enable domain search list support in udhcpc
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Commit Message

Alexey Brodkin April 8, 2019, 11 a.m. UTC
This is useful in networks with internal resources as it allows
to use much shorter names.

E.g. instead of "server.internal.company.com" it's possible
to use just "server" if DHCP server is configured with:
---------------------------->8-----------------------
option domain-search "internal.company.com";
---------------------------->8-----------------------

This improvement consists of 2 parts:

1. Enable handling of RFC3397 so DHCP client is ready for processing
   corresponding data from DHCP server.

2. Some DHCP servers always send out search list if it is set in server's
   configuration and some servers only provide search list if client
   asks for that (sending list of options it expectes to get).

   And exactly for those stubborn DHCP servers we need to add "-O search"
   to udhcp's command line via CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
Cc: Peter Korsgaard <peter@korsgaard.com>
---
 package/busybox/busybox.config | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Yann E. MORIN Aug. 3, 2019, 3:49 p.m. UTC | #1
Alexey, All,

On 2019-04-08 14:00 +0300, Alexey Brodkin spake thusly:
> This is useful in networks with internal resources as it allows
> to use much shorter names.
> 
> E.g. instead of "server.internal.company.com" it's possible
> to use just "server" if DHCP server is configured with:
> ---------------------------->8-----------------------
> option domain-search "internal.company.com";
> ---------------------------->8-----------------------
> 
> This improvement consists of 2 parts:
> 
> 1. Enable handling of RFC3397 so DHCP client is ready for processing
>    corresponding data from DHCP server.
> 
> 2. Some DHCP servers always send out search list if it is set in server's
>    configuration and some servers only provide search list if client
>    asks for that (sending list of options it expectes to get).
> 
>    And exactly for those stubborn DHCP servers we need to add "-O search"
>    to udhcp's command line via CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS.
> 
> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
> Cc: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
> Cc: Peter Korsgaard <peter@korsgaard.com>

Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>

Regards,
Yann E. MORIN.

> ---
>  package/busybox/busybox.config | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/package/busybox/busybox.config b/package/busybox/busybox.config
> index 1d9560d655..ab04854c83 100644
> --- a/package/busybox/busybox.config
> +++ b/package/busybox/busybox.config
> @@ -967,9 +967,9 @@ CONFIG_UDHCPC_DEFAULT_SCRIPT="/usr/share/udhcpc/default.script"
>  # CONFIG_FEATURE_UDHCP_PORT is not set
>  CONFIG_UDHCP_DEBUG=0
>  CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS=80
> -# CONFIG_FEATURE_UDHCP_RFC3397 is not set
> +CONFIG_FEATURE_UDHCP_RFC3397=y
>  CONFIG_FEATURE_UDHCP_8021Q=y
> -CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS="-R -n"
> +CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS="-R -n -O search"
>  
>  #
>  # Print Utilities
> -- 
> 2.16.2
> 
> _______________________________________________
> buildroot mailing list
> buildroot@busybox.net
> http://lists.busybox.net/mailman/listinfo/buildroot
Peter Korsgaard Aug. 3, 2019, 4:03 p.m. UTC | #2
>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

 > Alexey, All,
 > On 2019-04-08 14:00 +0300, Alexey Brodkin spake thusly:
 >> This is useful in networks with internal resources as it allows
 >> to use much shorter names.
 >> 
 >> E.g. instead of "server.internal.company.com" it's possible
 >> to use just "server" if DHCP server is configured with:
 ----------------------------> 8-----------------------
 >> option domain-search "internal.company.com";
 ----------------------------> 8-----------------------
 >> 
 >> This improvement consists of 2 parts:
 >> 
 >> 1. Enable handling of RFC3397 so DHCP client is ready for processing
 >> corresponding data from DHCP server.
 >> 
 >> 2. Some DHCP servers always send out search list if it is set in server's
 >> configuration and some servers only provide search list if client
 >> asks for that (sending list of options it expectes to get).
 >> 
 >> And exactly for those stubborn DHCP servers we need to add "-O search"
 >> to udhcp's command line via CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS.
 >> 
 >> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
 >> Cc: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
 >> Cc: Peter Korsgaard <peter@korsgaard.com>

 > Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>

Committed, thanks.

Notice: For a single domain, I believe you can just set

option domain-name "internal.company.com"

In the DHCP server config, which will work out of the box using the
classic (option 15) domain name option.
Alexey Brodkin Aug. 4, 2019, 7:51 a.m. UTC | #3
Hi Peter,

> -----Original Message-----
> From: Peter Korsgaard <jacmet@gmail.com> On Behalf Of Peter Korsgaard
> Sent: Saturday, August 3, 2019 7:04 PM
> To: Yann E. MORIN <yann.morin.1998@free.fr>
> Cc: Alexey Brodkin <abrodkin@synopsys.com>; buildroot@busybox.net; Ignacy Gawedzki
> <ignacy.gawedzki@green-communications.fr>; ARC Buildroot mailing list <arc-buildroot@synopsys.com>
> Subject: Re: [PATCH] busybox: Enable domain search list support in udhcpc
> 
> >>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:
> 
>  > Alexey, All,
>  > On 2019-04-08 14:00 +0300, Alexey Brodkin spake thusly:
>  >> This is useful in networks with internal resources as it allows
>  >> to use much shorter names.
>  >>
>  >> E.g. instead of "server.internal.company.com" it's possible
>  >> to use just "server" if DHCP server is configured with:
>  ----------------------------> 8-----------------------
>  >> option domain-search "internal.company.com";
>  ----------------------------> 8-----------------------
>  >>
>  >> This improvement consists of 2 parts:
>  >>
>  >> 1. Enable handling of RFC3397 so DHCP client is ready for processing
>  >> corresponding data from DHCP server.
>  >>
>  >> 2. Some DHCP servers always send out search list if it is set in server's
>  >> configuration and some servers only provide search list if client
>  >> asks for that (sending list of options it expectes to get).
>  >>
>  >> And exactly for those stubborn DHCP servers we need to add "-O search"
>  >> to udhcp's command line via CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS.
>  >>
>  >> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
>  >> Cc: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
>  >> Cc: Peter Korsgaard <peter@korsgaard.com>
> 
>  > Acked-by: Yann E. MORIN <yann.morin.1998@free.fr>
> 
> Committed, thanks.
> 
> Notice: For a single domain, I believe you can just set
> 
> option domain-name "internal.company.com"

Sure that's perfectly possible.
But in some networks (for example) like we have in the company
they do use search domains and w/o it boards connected to the network
get incomplete configuration and cannot access internal resources.

-Alexey
Peter Korsgaard Aug. 30, 2019, 8:32 p.m. UTC | #4
>>>>> "Yann" == Yann E MORIN <yann.morin.1998@free.fr> writes:

 > On 2019-04-08 14:00 +0300, Alexey Brodkin spake thusly:
 >> This is useful in networks with internal resources as it allows
 >> to use much shorter names.
 >> 
 >> E.g. instead of "server.internal.company.com" it's possible
 >> to use just "server" if DHCP server is configured with:
 ----------------------------> 8-----------------------
 >> option domain-search "internal.company.com";
 ----------------------------> 8-----------------------
 >> 
 >> This improvement consists of 2 parts:
 >> 
 >> 1. Enable handling of RFC3397 so DHCP client is ready for processing
 >> corresponding data from DHCP server.
 >> 
 >> 2. Some DHCP servers always send out search list if it is set in server's
 >> configuration and some servers only provide search list if client
 >> asks for that (sending list of options it expectes to get).
 >> 
 >> And exactly for those stubborn DHCP servers we need to add "-O search"
 >> to udhcp's command line via CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS.
 >> 
 >> Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
 >> Cc: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
 >> Cc: Peter Korsgaard <peter@korsgaard.com>

Committed to 2019.02.x and 2019.05.x, thanks.

Patch
diff mbox series

diff --git a/package/busybox/busybox.config b/package/busybox/busybox.config
index 1d9560d655..ab04854c83 100644
--- a/package/busybox/busybox.config
+++ b/package/busybox/busybox.config
@@ -967,9 +967,9 @@  CONFIG_UDHCPC_DEFAULT_SCRIPT="/usr/share/udhcpc/default.script"
 # CONFIG_FEATURE_UDHCP_PORT is not set
 CONFIG_UDHCP_DEBUG=0
 CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS=80
-# CONFIG_FEATURE_UDHCP_RFC3397 is not set
+CONFIG_FEATURE_UDHCP_RFC3397=y
 CONFIG_FEATURE_UDHCP_8021Q=y
-CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS="-R -n"
+CONFIG_IFUPDOWN_UDHCPC_CMD_OPTIONS="-R -n -O search"
 
 #
 # Print Utilities