freebsd-dev/sys/net/route/nhop_var.h

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Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Alexander V. Chernikov
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* This header file contains private definitions for nexthop routing.
*
* Header is not intended to be included by the code external to the
* routing subsystem.
*/
#ifndef _NET_ROUTE_NHOP_VAR_H_
#define _NET_ROUTE_NHOP_VAR_H_
/* define nhop hash table */
struct nhop_priv;
CHT_SLIST_DEFINE(nhops, struct nhop_priv);
/* produce hash value for an object */
#define nhops_hash_obj(_obj) hash_priv(_obj)
/* compare two objects */
#define nhops_cmp(_one, _two) cmp_priv(_one, _two)
/* next object accessor */
#define nhops_next(_obj) (_obj)->nh_next
struct nh_control {
struct nhops_head nh_head; /* hash table head */
struct bitmask_head nh_idx_head; /* nhop index head */
struct rwlock ctl_lock; /* overall ctl lock */
struct rib_head *ctl_rh; /* pointer back to rnh */
struct epoch_context ctl_epoch_ctx; /* epoch ctl helper */
};
#define NHOPS_WLOCK(ctl) rw_wlock(&(ctl)->ctl_lock)
#define NHOPS_RLOCK(ctl) rw_rlock(&(ctl)->ctl_lock)
#define NHOPS_WUNLOCK(ctl) rw_wunlock(&(ctl)->ctl_lock)
#define NHOPS_RUNLOCK(ctl) rw_runlock(&(ctl)->ctl_lock)
#define NHOPS_LOCK_INIT(ctl) rw_init(&(ctl)->ctl_lock, "nhop_ctl")
#define NHOPS_LOCK_DESTROY(ctl) rw_destroy(&(ctl)->ctl_lock)
#define NHOPS_WLOCK_ASSERT(ctl) rw_assert(&(ctl)->ctl_lock, RA_WLOCKED)
/* Control plane-only nhop data */
struct nhop_object;
struct nhop_priv {
uint32_t nh_idx; /* nexthop index */
uint8_t nh_family; /* address family of the lookup */
uint16_t nh_type; /* nexthop type */
void *cb_func; /* function handling additional rewrite caps */
u_int nh_refcnt; /* number of references, refcount(9) */
u_int nh_linked; /* refcount(9), == 2 if linked to the list */
int rt_flags; /* routing flags for the control plane */
struct nhop_object *nh; /* backreference to the dataplane nhop */
struct nh_control *nh_control; /* backreference to the rnh */
struct nhop_priv *nh_next; /* hash table membership */
struct vnet *nh_vnet; /* vnet nhop belongs to */
Introduce nexthop objects and new routing KPI. This is the foundational change for the routing subsytem rearchitecture. More details and goals are available in https://reviews.freebsd.org/D24141 . This patch introduces concept of nexthop objects and new nexthop-based routing KPI. Nexthops are objects, containing all necessary information for performing the packet output decision. Output interface, mtu, flags, gw address goes there. For most of the cases, these objects will serve the same role as the struct rtentry is currently serving. Typically there will be low tens of such objects for the router even with multiple BGP full-views, as these objects will be shared between routing entries. This allows to store more information in the nexthop. New KPI: struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, uint32_t flowid); struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, uint32_t flowid); These 2 function are intended to replace all all flavours of <in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous fib[46]-generation functions. Upon successful lookup, they return nexthop object which is guaranteed to exist within current NET_EPOCH. If longer lifetime is desired, one can specify NHR_REF as a flag and get a referenced version of the nexthop. Reference semantic closely resembles rtentry one, allowing sed-style conversion. Additionally, another 2 functions are introduced to support uRPF functionality inside variety of our firewalls. Their primary goal is to hide the multipath implementation details inside the routing subsystem, greatly simplifying firewalls implementation: int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid, uint32_t flags, const struct ifnet *src_if); All functions have a separate scopeid argument, paving way to eliminating IPv6 scope embedding and allowing to support IPv4 link-locals in the future. Structure changes: * rtentry gets new 'rt_nhop' pointer, slightly growing the overall size. * rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz. Old KPI: During the transition state old and new KPI will coexists. As there are another 4-5 decent-sized conversion patches, it will probably take a couple of weeks. To support both KPIs, fields not required by the new KPI (most of rtentry) has to be kept, resulting in the temporary size increase. Once conversion is finished, rtentry will notably shrink. More details: * architectural overview: https://reviews.freebsd.org/D24141 * list of the next changes: https://reviews.freebsd.org/D24232 Reviewed by: ae,glebius(initial version) Differential Revision: https://reviews.freebsd.org/D24232
2020-04-12 14:30:00 +00:00
struct epoch_context nh_epoch_ctx; /* epoch data for nhop */
};
#define NH_IS_PINNED(_nh) ((_nh)->nh_priv->rt_flags & RTF_PINNED)
/* nhop.c */
struct nhop_priv *find_nhop(struct nh_control *ctl,
const struct nhop_priv *nh_priv);
int link_nhop(struct nh_control *ctl, struct nhop_priv *nh_priv);
struct nhop_priv *unlink_nhop(struct nh_control *ctl, struct nhop_priv *nh_priv);
/* nhop_ctl.c */
int cmp_priv(const struct nhop_priv *_one, const struct nhop_priv *_two);
#endif