This change is based on the nexthop objects landed in D24232. The change introduces the concept of nexthop groups. Each group contains the collection of nexthops with their relative weights and a dataplane-optimized structure to enable efficient nexthop selection. Simular to the nexthops, nexthop groups are immutable. Dataplane part gets compiled during group creation and is basically an array of nexthop pointers, compiled w.r.t their weights. With this change, `rt_nhop` field of `struct rtentry` contains either nexthop or nexthop group. They are distinguished by the presense of NHF_MULTIPATH flag. All dataplane lookup functions returns pointer to the nexthop object, leaving nexhop groups details inside routing subsystem. User-visible changes: The change is intended to be backward-compatible: all non-mpath operations should work as before with ROUTE_MPATH and net.route.multipath=1. All routes now comes with weight, default weight is 1, maximum is 2^24-1. Current maximum multipath group width is statically set to 64. This will become sysctl-tunable in the followup changes. Using functionality: * Recompile kernel with ROUTE_MPATH * set net.route.multipath to 1 route add -6 2001:db8::/32 2001:db8::2 -weight 10 route add -6 2001:db8::/32 2001:db8::3 -weight 20 netstat -6On Nexthop groups data Internet6: GrpIdx NhIdx Weight Slots Gateway Netif Refcnt 1 ------- ------- ------- --------------------------------------- --------- 1 13 10 1 2001:db8::2 vlan2 14 20 2 2001:db8::3 vlan2 Next steps: * Land outbound hashing for locally-originated routes ( D26523 ). * Fix net/bird multipath (net/frr seems to work fine) * Add ROUTE_MPATH to GENERIC * Set net.route.multipath=1 by default Tested by: olivier Reviewed by: glebius Relnotes: yes Differential Revision: https://reviews.freebsd.org/D26449 |
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.. | ||
bpf.c | ||
common.c | ||
common.h | ||
if.c | ||
inet6.c | ||
inet.c | ||
ipsec.c | ||
main.c | ||
Makefile | ||
Makefile.depend | ||
Makefile.depend.options | ||
mbuf.c | ||
mroute6.c | ||
mroute.c | ||
netgraph.c | ||
netisr.c | ||
netstat.1 | ||
netstat.h | ||
nhgrp.c | ||
nhops.c | ||
nlist_symbols | ||
pfkey.c | ||
route.c | ||
sctp.c | ||
unix.c |