[cmaster-next] [PATCH] bgpd: Fix crashes when no default bgp instance is configured.

[Donald Sharp]

Lou -

This fixes the crashes that are found by the new topotest testing
suite that Martin has created.  As stated in the commit note, I have
done no work to ensure that vnc is going to work correctly without a
default bgp instance.  We just no longer crash with these tests.
Additionally I see lots of unguarded debugs in the vnc code.  I
believe these need to be cleaned up as well in some manner, thoughts?

Martin -

The bgp tests still fail, from what appears to be display output
change.  How would you like to proceed here?  Send a patch to fix this
issue to the topotests github doohickey?


donald

On Thu, Dec 1, 2016 at 9:11 AM, Donald Sharp <sharpd at cumulusnetworks.com> wrote:
> The vnc code assumes that bgp must have a default instance.
> This code change checks to make sure that we do before
> proceeding.  It makes no assurances that vnc will behave
> correctly without a default instance.
>
> Signed-off-by: Donald Sharp <sharpd at cumulusnetworks.com>
> ---
>  bgpd/rfapi/rfapi_import.c   |  3 ++-
>  bgpd/rfapi/vnc_import_bgp.c | 17 +++++++++++++++--
>  2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/bgpd/rfapi/rfapi_import.c b/bgpd/rfapi/rfapi_import.c
> index 8783024..77da4f9 100644
> --- a/bgpd/rfapi/rfapi_import.c
> +++ b/bgpd/rfapi/rfapi_import.c
> @@ -4414,7 +4414,8 @@ rfapiProcessPeerDown (struct peer *peer)
>     */
>
>    bgp = bgp_get_default ();     /* assume 1 instance for now */
> -  assert (bgp);
> +  if (!bgp)
> +    return;
>
>    h = bgp->rfapi;
>    assert (h);
> diff --git a/bgpd/rfapi/vnc_import_bgp.c b/bgpd/rfapi/vnc_import_bgp.c
> index 4215ce2..dc2640a 100644
> --- a/bgpd/rfapi/vnc_import_bgp.c
> +++ b/bgpd/rfapi/vnc_import_bgp.c
> @@ -208,12 +208,17 @@ prefix_bag_free (void *pb)
>  static void
>  print_rhn_list (const char *tag1, const char *tag2)
>  {
> -  struct bgp *bgp = bgp_get_default ();
> -  struct skiplist *sl = bgp->rfapi->resolve_nve_nexthop;
> +  struct bgp *bgp;
> +  struct skiplist *sl;
>    struct skiplistnode *p;
>    struct prefix_bag *pb;
>    int count = 0;
>
> +  bgp = bgp_get_default ();
> +  if (!bgp)
> +    return;
> +
> +  sl = bgp->frapi->resolve_nve_nexthop;
>    if (!sl)
>      {
>        zlog_debug ("%s: %s: RHN List is empty", (tag1 ? tag1 : ""),
> @@ -251,6 +256,8 @@ vnc_rhnck (char *tag)
>    struct skiplistnode *p;
>
>    bgp = bgp_get_default ();
> +  if (!bgp)
> +    return;
>    sl = bgp->rfapi->resolve_nve_nexthop;
>
>    if (!sl)
> @@ -1798,6 +1805,9 @@ vnc_import_bgp_exterior_add_route_it (
>    struct bgp *bgp_default = bgp_get_default ();
>    afi_t afi = family2afi (prefix->family);
>
> +  if (!bgp_default)
> +    return;
> +
>    h = bgp_default->rfapi;
>    hc = bgp_default->rfapi_cfg;
>
> @@ -1992,6 +2002,9 @@ vnc_import_bgp_exterior_del_route (
>    afi_t afi = family2afi (prefix->family);
>    struct bgp *bgp_default = bgp_get_default ();
>
> +  if (!bgp_default)
> +    return;
> +
>    memset (&pfx_orig_nexthop, 0, sizeof (struct prefix));        /* keep valgrind happy */
>
>    h = bgp_default->rfapi;
> --
> 2.7.4
>