Subject: Re: Report: iproute2 build broken?

From: Ido Schimmel <[email-masked]>
Date: Mon, 4 Jul 2022 20:17:51 +0300

On Mon, Jul 04, 2022 at 12:59:45PM -0400, Jamal Hadi Salim wrote:
> Thanks Ido. That fixed it.
> General question: do we need a "stable" iproute2?

Maybe a new point release is enough (e.g., 5.18.1)?

I see that's what Stephen did the last time something similar happened:

$ git log v4.14.0^..v4.14.1

commit 212b52299e90a369373b9e38924b9492df695559
Author: Stephen Hemminger <[email-masked]>
Date:   Mon Nov 13 10:09:57 2017 -0800

    v4.14.1

commit b867d46dafee4ac81acecd2d398c392eb43b50bb
Author: Stephen Hemminger <[email-masked]>
Date:   Mon Nov 13 10:08:39 2017 -0800

    utils: remove duplicate include of ctype.h
    
    Signed-off-by: Stephen Hemminger <[email-masked]>

commit aba736dc251ee7aa7c2035e18bffc37b18f05222
Author: Leon Romanovsky <[email-masked]>
Date:   Mon Nov 13 12:21:19 2017 +0200

    ip: Fix compilation break on old systems
    
    As was reported [1], the iproute2 fails to compile on old systems,
    in Cong's case, it was Fedora 19, in our case it was RedHat 7.2, which
    failed with the following errors during compilation:
    
    ipxfrm.c: In function ‘xfrm_selector_print’:
    ipxfrm.c:479:7: error: ‘IPPROTO_MH’ undeclared (first use in this
    function)
      case IPPROTO_MH:
           ^
    ipxfrm.c:479:7: note: each undeclared identifier is reported only once
    for each function it appears in
    ipxfrm.c: In function ‘xfrm_selector_upspec_parse’:
    ipxfrm.c:1345:8: error: ‘IPPROTO_MH’ undeclared (first use in this
    function)
       case IPPROTO_MH:
            ^                                                                                                                                                            make[1]: *** [ipxfrm.o] Error 1
    
    The reason to it is the order of headers files. The IPPROTO_MH field is
    set in kernel's UAPI header file (in6.h), but only in case
    __UAPI_DEF_IPPROTO_V6 is set before. That define comes from other kernel's
    header file (libc-compat.h) and is set in case there are no previous
    libc relevant declarations.
    
    In ip code, the include of <netdb.h> causes to indirect inclusion of
    <netinet/in.h> and it sets __UAPI_DEF_IPPROTO_V6 to be zero and prevents from
    IPPROTO_MH declaration.
    
    This patch takes the simplest possible approach to fix the compilation
    error by checking if IPPROTO_MH was defined before and in case it
    wasn't, it defines it to be the same as in the kernel.
    
    [1] https://www.spinics.net/lists/netdev/msg463980.html
    
    Cc: Cong Wang <[email-masked]>
    Cc: Riad Abo Raed <[email-masked]>
    Signed-off-by: Leon Romanovsky <[email-masked]>

commit 7d14d00795c334a288f1733bfdabdf363a7f962c
Author: Stephen Hemminger <[email-masked]>
Date:   Sun Nov 12 16:29:43 2017 -0800

    v4.14.0