netdev - Re: [PATCH v3 net-next 2/5] ipv4: Add fib_nh_common to fib

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b8610778-a933-9a48-1499-513f07a84f22@gmail.com>
Date:   Tue, 2 Apr 2019 11:18:16 -0600
From:   David Ahern <dsahern@...il.com>
To:     Martin Lau <kafai@...com>, David Ahern <dsahern@...nel.org>
Cc:     "davem@...emloft.net" <davem@...emloft.net>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "idosch@...lanox.com" <idosch@...lanox.com>
Subject: Re: [PATCH v3 net-next 2/5] ipv4: Add fib_nh_common to fib_result

On 4/2/19 11:10 AM, Martin Lau wrote:
>> @@ -182,11 +183,10 @@ struct fib_result_nl {
>>  	int             err;
>>  };
>>  
>> -#ifdef CONFIG_IP_ROUTE_MULTIPATH
>> -#define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
> If nh_sel is still needed, I am likely missing something to understand why

It is part of the uapi, so I can not delete it.

> a new '*nhc' pointer is needed.  Is nhc always pointing to the "nh_sel"-ed nh,
> like the current FIB_RES_NH() does?

Right now, yes. In the future, no.

> 
> Can you explain more on the commit message:
> "Later, fib_nh can point to data with a nexthop struct."

Today:

fib_info  --> fib_nh
              fib_nh
              ...
              fib_nh

With nexthops as a separate object

fib_info --> nexthop --> fib_nh


or with a nexthop group:

fib_info --> nexthop --> nexthop --> fib_nh
                         nexthop --> fib_nh
                         ...
                         nexthop --> fib_nh

I outlined this here:
    https://www.mail-archive.com/netdev@vger.kernel.org/msg290606.html

Now, the UAPI that uses nhsel still works in the sense that it tells
which fib_nh is used for a lookup even though internally it is part of a
different struct.