tree e3e6c66af5ed0a6d7270a842986487ba5e8c8c26
parent 518a4b7eadcba567f01061e6659d8179380efcdf
author Paul Jakma <paul.jakma@hpe.com> 1454605218 +0000
committer Paul Jakma <paul.jakma@hpe.com> 1457459602 +0000

bgpd: Remove the double-pass parsing of NLRIs

* bgpd parses NLRIs twice, a first pass "sanity check" and then a second pass
  that changes actual state. For most AFI/SAFIs this is done by
  bgp_nlri_sanity_check and bgp_nlri_parse, which are almost identical.

  As the required action on a syntactic error in an NLRI is to NOTIFY and
  shut down the session, it should be acceptable to just do a one pass
  parse.  There is no need to atomically handle the NLRIs.

* bgp_route.h: (bgp_nlri_sanity_check) Delete
* bgp_route.c: (bgp_nlri_parse) Make the prefixlen size check more general
  and don't hard-code AFI/SAFI details, e.g. use prefix_blen library function.

  Add error logs consistent with bgp_nlri_sanity_check as much as possible.

  Add a "defense in depth" type check of the prefixlen against the sizeof
  the (struct prefix) storage - ala bgp_nlri_parse_vpn.
  Update standards text from draft RFC4271 to the actual RFC4271 text.

  Extend the semantic consistency test of IPv6. E.g. it should skip mcast
  NLRIs for unicast safi as v4 does.

* bgp_mplsvpn.{c,h}: Delete bgp_nlri_sanity_check_vpn and make
  bgp_nlri_parse_vpn_body the bgp_nlri_parse_vpn function again.

  (bgp_nlri_parse_vpn) Remove the notifies.  The sanity checks were
  responsible for this, but bgp_update_receive handles sending NOTIFY
  generically for bgp_nlri_parse.

* bgp_attr.c: (bgp_mp_reach_parse,bgp_mp_unreach_parse) Delete sanity check.
  NLRI parsing done after attr parsing by bgp_update_receive.

Arising out of discussions on the need for two-pass NLRI parse with:

Lou Berger <lberger@labn.net>
Donald Sharp <sharpd@cumulusnetworks.com>