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. v15: - More fixes, after feedback and discussions. Notably: - Added a secondary lookup in fwd_neigh_mac_get(), so that we respond with the guest GW's MAC address in case the primary lookup fails. - Removed guest_gw IP address as 'blocker' entry in the neighbor table. It is ok to let the host GW MAC address go through if the GW addresses match, and even when they don't we found it isn't needed. - Removed previous patch #2 about no_map_gw, since the change it introduced only was needed by the the functionality we just removed as described above. Jon Maloy (9): netlink: add subscription on changes in NDP/ARP table 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 | 59 +++++++++++++- arp.h | 2 + epoll_type.h | 2 + flow.c | 2 + flow.h | 2 + fwd.c | 212 +++++++++++++++++++++++++++++++++++++++++++++++++ fwd.h | 7 ++ icmp.c | 8 +- inany.c | 1 + ndp.c | 16 +++- ndp.h | 1 + netlink.c | 208 +++++++++++++++++++++++++++++++++++++++++++++++- netlink.h | 4 + passt.c | 17 ++-- passt.h | 3 +- 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 + 26 files changed, 623 insertions(+), 83 deletions(-) -- 2.50.1