[PATCH v14 00/10] Use true MAC address of LAN local remote hosts

[Jon Maloy <jmaloy@redhat.com>]

Bug #120 asks us to use the true MAC addresses of LAN local
remote hosts, since some programs need this information.
These commits introduces this for ARP, NDP, UDP, TCP and
ICMP.

---
v3: Updated according to feedback from Stefano and David:
    - Made the ARP/NDP lookup call filter out the requested address
      by itself, qualified by the index if the template interface
    - Moved the flow specific MAC address from struct flowside to
      struct flow_common.

v4: - Updated according to feedback from David and Stefan
    - Added a cache table for ARP/NDP table contents

v5: - Updated according to feedback from David and Stefan
    - Added cache table entries to FIFO/LRU queue
    - New criteria for when to consult ARP/NDP

v6: - Simplified and merged mac cache table commits
    - Other changes after feedback from David.
v7: - Fixes in patch #2 based on feedback from David
      and Stefano.
v8: - Redesigned netlink and cache table part to be based
      on a subscription model.
v8: - Small fix to patch #2 so that we cover the case
      when a MAC addess for a host has changed.
    - Added a commit where we send a gratuitous ARP/
      unsolicitated NA to the guest when a new host is
      added to the neighbour cache table.
v10: - Some fixes after feedback from David Gibson
     - Reordered: Moved patch #9 to position #3.
     - Added synchronization step between ARP/NDP
       table contents and the neigbour table at
       initialization. This reduces the number of
       "false" ARP/NDP replies drastically, but not
       completly. 
     - (Next step could be to scan over the flow table
       and update affeced entries when we receive
       a MAC address update.)
v11: - Corrected the gratuitous ARP implementation to use
       the "ARP Announcement" model instead of the
       "Gratuitous ARP reply" model.
v12: - Updated based on feedback from David and Stefano
     - Added special handling of default GW and loopback
       addresses.
v13: - Updated based on discussion with David and Stefano
     - Conceptually moved to only considering guest-side
       visible addresss. A lot of things became simpler
       and clearer through this change. Thank you, David.
     - Introduced a 'permanent' flag in the special
       entries representing addessed mapping to own host
       and conditionally the guest gw. This flag indicates
       those entries cannot be altered by possible remote hosts
       shadowed by these addresses. Suggested by Stefano.
     - Reordered patch ##4 and 5, since #5 cannot work
       correctly for NDP unsolicited NA until #4 is in place.
     - Added a new commit #2 to get later access to the flag
       no_map_gw. It was wrong to call fwd_neigh_table_init()
       from inside conf(), it has to be done in main() after
       random_init() and tap_backend_init().
v14: - Some fixes after feedback from David Gibson, notably
     - Moved the call to nat_inbound() from fwd.c to netlink.c
     - Added RFC quotes to explain the format of ARP announce
       messages.

Jon Maloy (10):
  netlink: add subscription on changes in NDP/ARP table
  passt: add no_map_gw flag to struct ctx
  fwd: Add cache table for ARP/NDP contents
  arp/ndp: respond with true MAC address of LAN local remote hosts
  arp/ndp: send ARP announcement / unsolicited NA when neigbour entry
    added
  flow: add MAC address of LAN local remote hosts to flow
  udp: forward external source MAC address through tap interface
  tcp: forward external source MAC address through tap interface
  tap: change signature of function tap_push_l2h()
  icmp: let icmp use mac address from flowside structure

 arp.c          |  58 ++++++++++++-
 arp.h          |   2 +
 conf.c         |  10 +--
 epoll_type.h   |   2 +
 flow.c         |   2 +
 flow.h         |   2 +
 fwd.c          | 227 +++++++++++++++++++++++++++++++++++++++++++++++++
 fwd.h          |   7 ++
 icmp.c         |   8 +-
 inany.c        |   1 +
 ndp.c          |  16 +++-
 ndp.h          |   1 +
 netlink.c      | 215 +++++++++++++++++++++++++++++++++++++++++++++-
 netlink.h      |   4 +
 passt.c        |  17 ++--
 passt.h        |   4 +-
 pasta.c        |   2 +-
 tap.c          |  24 +++---
 tap.h          |   7 +-
 tcp.c          |  20 ++++-
 tcp.h          |   2 +-
 tcp_buf.c      |  37 ++++----
 tcp_internal.h |   4 +-
 tcp_vu.c       |   5 +-
 udp.c          |  57 ++++++++-----
 udp.h          |   2 +-
 util.h         |   2 +
 27 files changed, 650 insertions(+), 88 deletions(-)

-- 
2.50.1