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freebsd-dev/sys/net/route/route_var.h
Alexander V. Chernikov da187ddb3d * Add rib_<add|del|change>_route() functions to manipulate the routing table. 
The main driver for the change is the need to improve notification mechanism.
Currently callers guess the operation data based on the rtentry structure
 returned in case of successful operation result. There are two problems with
 this appoach. First is that it doesn't provide enough information for the
 upcoming multipath changes, where rtentry refers to a new nexthop group,
 and there is no way of guessing which paths were added during the change.
 Second is that some rtentry fields can change during notification and
 protecting from it by requiring customers to unlock rtentry is not desired.

Additionally, as the consumers such as rtsock do know which operation they
 request in advance, making explicit add/change/del versions of the functions
 makes sense, especially given the functions don't share a lot of code.

With that in mind, introduce rib_cmd_info notification structure and
 rib_<add|del|change>_route() functions, with mandatory rib_cmd_info pointer.
 It will be used in upcoming generalized notifications.

* Move definitions of the new functions and some other functions/structures
 used for the routing table manipulation to a separate header file,
 net/route/route_ctl.h. net/route.h is a frequently used file included in
 ~140 places in kernel, and 90% of the users don't need these definitions.

Reviewed by:		ae
Differential Revision:	https://reviews.freebsd.org/D25067
2020-06-01 20:49:42 +00:00

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/*-
* Copyright (c) 2015-2016
* Alexander V. Chernikov <melifaro@FreeBSD.org>
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* $FreeBSD$
*/
#ifndef _NET_ROUTE_VAR_H_
#define _NET_ROUTE_VAR_H_
#ifndef RNF_NORMAL
#include <net/radix.h>
#endif
#include <sys/ck.h>
#include <sys/epoch.h>
#include <netinet/in.h> /* struct sockaddr_in */
#include <sys/counter.h>
struct nh_control;
typedef int rnh_preadd_entry_f_t(u_int fibnum, const struct sockaddr *addr,
const struct sockaddr *mask, struct nhop_object *nh);
struct rib_head {
struct radix_head head;
rn_matchaddr_f_t *rnh_matchaddr; /* longest match for sockaddr */
rn_addaddr_f_t *rnh_addaddr; /* add based on sockaddr*/
rn_deladdr_f_t *rnh_deladdr; /* remove based on sockaddr */
rn_lookup_f_t *rnh_lookup; /* exact match for sockaddr */
rn_walktree_t *rnh_walktree; /* traverse tree */
rn_walktree_from_t *rnh_walktree_from; /* traverse tree below a */
rnh_preadd_entry_f_t *rnh_preadd; /* hook to alter record prior to insertion */
rt_gen_t rnh_gen; /* generation counter */
int rnh_multipath; /* multipath capable ? */
struct radix_node rnh_nodes[3]; /* empty tree for common case */
struct rmlock rib_lock; /* config/data path lock */
struct radix_mask_head rmhead; /* masks radix head */
struct vnet *rib_vnet; /* vnet pointer */
int rib_family; /* AF of the rtable */
u_int rib_fibnum; /* fib number */
struct callout expire_callout; /* Callout for expiring dynamic routes */
time_t next_expire; /* Next expire run ts */
struct nh_control *nh_control; /* nexthop subsystem data */
CK_STAILQ_HEAD(, rib_subscription) rnh_subscribers;/* notification subscribers */
};
#define RIB_RLOCK_TRACKER struct rm_priotracker _rib_tracker
#define RIB_LOCK_INIT(rh) rm_init(&(rh)->rib_lock, "rib head lock")
#define RIB_LOCK_DESTROY(rh) rm_destroy(&(rh)->rib_lock)
#define RIB_RLOCK(rh) rm_rlock(&(rh)->rib_lock, &_rib_tracker)
#define RIB_RUNLOCK(rh) rm_runlock(&(rh)->rib_lock, &_rib_tracker)
#define RIB_WLOCK(rh) rm_wlock(&(rh)->rib_lock)
#define RIB_WUNLOCK(rh) rm_wunlock(&(rh)->rib_lock)
#define RIB_LOCK_ASSERT(rh) rm_assert(&(rh)->rib_lock, RA_LOCKED)
#define RIB_WLOCK_ASSERT(rh) rm_assert(&(rh)->rib_lock, RA_WLOCKED)
/* Constants */
#define RIB_MAX_RETRIES 3
/* Macro for verifying fields in af-specific 'struct route' structures */
#define CHK_STRUCT_FIELD_GENERIC(_s1, _f1, _s2, _f2) \
_Static_assert(sizeof(((_s1 *)0)->_f1) == sizeof(((_s2 *)0)->_f2), \
"Fields " #_f1 " and " #_f2 " size differs"); \
_Static_assert(__offsetof(_s1, _f1) == __offsetof(_s2, _f2), \
"Fields " #_f1 " and " #_f2 " offset differs");
#define _CHK_ROUTE_FIELD(_route_new, _field) \
CHK_STRUCT_FIELD_GENERIC(struct route, _field, _route_new, _field)
#define CHK_STRUCT_ROUTE_FIELDS(_route_new) \
_CHK_ROUTE_FIELD(_route_new, ro_nh) \
_CHK_ROUTE_FIELD(_route_new, ro_lle) \
_CHK_ROUTE_FIELD(_route_new, ro_prepend)\
_CHK_ROUTE_FIELD(_route_new, ro_plen) \
_CHK_ROUTE_FIELD(_route_new, ro_flags) \
_CHK_ROUTE_FIELD(_route_new, ro_mtu) \
_CHK_ROUTE_FIELD(_route_new, spare)
#define CHK_STRUCT_ROUTE_COMPAT(_ro_new, _dst_new) \
CHK_STRUCT_ROUTE_FIELDS(_ro_new); \
_Static_assert(__offsetof(struct route, ro_dst) == __offsetof(_ro_new, _dst_new),\
"ro_dst and " #_dst_new " are at different offset")
struct rib_head *rt_tables_get_rnh(int fib, int family);
void rt_mpath_init_rnh(struct rib_head *rnh);
int rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum);
void rt_setmetrics(const struct rt_addrinfo *info, struct rtentry *rt);
#ifdef RADIX_MPATH
struct radix_node *rt_mpath_unlink(struct rib_head *rnh,
struct rt_addrinfo *info, struct rtentry *rto, int *perror);
#endif
struct rib_cmd_info;
int add_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc);
int del_route(struct rib_head *rnh, struct rt_addrinfo *info,
struct rib_cmd_info *rc);
int change_route(struct rib_head *, struct rt_addrinfo *,
struct rib_cmd_info *rc);
VNET_PCPUSTAT_DECLARE(struct rtstat, rtstat);
#define RTSTAT_ADD(name, val) \
VNET_PCPUSTAT_ADD(struct rtstat, rtstat, name, (val))
#define RTSTAT_INC(name) RTSTAT_ADD(name, 1)
/*
* Convert a 'struct radix_node *' to a 'struct rtentry *'.
* The operation can be done safely (in this code) because a
* 'struct rtentry' starts with two 'struct radix_node''s, the first
* one representing leaf nodes in the routing tree, which is
* what the code in radix.c passes us as a 'struct radix_node'.
*
* But because there are a lot of assumptions in this conversion,
* do not cast explicitly, but always use the macro below.
*/
#define RNTORT(p) ((struct rtentry *)(p))
struct rtentry {
struct radix_node rt_nodes[2]; /* tree glue, and other values */
/*
* XXX struct rtentry must begin with a struct radix_node (or two!)
* because the code does some casts of a 'struct radix_node *'
* to a 'struct rtentry *'
*/
#define rt_key(r) (*((struct sockaddr **)(&(r)->rt_nodes->rn_key)))
#define rt_mask(r) (*((struct sockaddr **)(&(r)->rt_nodes->rn_mask)))
#define rt_key_const(r) (*((const struct sockaddr * const *)(&(r)->rt_nodes->rn_key)))
#define rt_mask_const(r) (*((const struct sockaddr * const *)(&(r)->rt_nodes->rn_mask)))
/*
* 2 radix_node structurs above consists of 2x6 pointers, leaving
* 4 pointers (32 bytes) of the second cache line on amd64.
*
*/
struct nhop_object *rt_nhop; /* nexthop data */
union {
/*
* Destination address storage.
* sizeof(struct sockaddr_in6) == 28, however
* the dataplane-relevant part (e.g. address) lies
* at offset 8..24, making the address not crossing
* cacheline boundary.
*/
struct sockaddr_in rt_dst4;
struct sockaddr_in6 rt_dst6;
struct sockaddr rt_dst;
char rt_dstb[28];
};
int rt_flags; /* up/down?, host/net */
u_long rt_weight; /* absolute weight */
u_long rt_expire; /* lifetime for route, e.g. redirect */
#define rt_endzero rt_mtx
struct mtx rt_mtx; /* mutex for routing entry */
struct rtentry *rt_chain; /* pointer to next rtentry to delete */
struct epoch_context rt_epoch_ctx; /* net epoch tracker */
};
#define RT_LOCK_INIT(_rt) \
mtx_init(&(_rt)->rt_mtx, "rtentry", NULL, MTX_DEF | MTX_DUPOK | MTX_NEW)
#define RT_LOCK(_rt) mtx_lock(&(_rt)->rt_mtx)
#define RT_UNLOCK(_rt) mtx_unlock(&(_rt)->rt_mtx)
#define RT_LOCK_DESTROY(_rt) mtx_destroy(&(_rt)->rt_mtx)
#define RT_LOCK_ASSERT(_rt) mtx_assert(&(_rt)->rt_mtx, MA_OWNED)
#define RT_UNLOCK_COND(_rt) do { \
if (mtx_owned(&(_rt)->rt_mtx)) \
mtx_unlock(&(_rt)->rt_mtx); \
} while (0)
/*
* With the split between the routing entry and the nexthop,
* rt_flags has to be split between these 2 entries. As rtentry
* mostly contains prefix data and is thought to be generic enough
* so one can transparently change the nexthop pointer w/o requiring
* any other rtentry changes, most of rt_flags shifts to the particular nexthop.
* /
*
* RTF_UP: rtentry, as an indication that it is linked.
* RTF_HOST: rtentry, nhop. The latter indication is needed for the datapath
* RTF_DYNAMIC: nhop, to make rtentry generic.
* RTF_MODIFIED: nhop, to make rtentry generic. (legacy)
* -- "native" path (nhop) properties:
* RTF_GATEWAY, RTF_STATIC, RTF_PROTO1, RTF_PROTO2, RTF_PROTO3, RTF_FIXEDMTU,
* RTF_PINNED, RTF_REJECT, RTF_BLACKHOLE, RTF_BROADCAST
*/
/* Nexthop rt flags mask */
#define NHOP_RT_FLAG_MASK (RTF_GATEWAY | RTF_HOST | RTF_REJECT | RTF_DYNAMIC | \
RTF_MODIFIED | RTF_STATIC | RTF_BLACKHOLE | RTF_PROTO1 | RTF_PROTO2 | \
RTF_PROTO3 | RTF_FIXEDMTU | RTF_PINNED | RTF_BROADCAST)
/* rtentry rt flag mask */
#define RTE_RT_FLAG_MASK (RTF_UP | RTF_HOST)
/* Nexthop selection */
#define _NH2MP(_nh) ((struct nhgrp_object *)(_nh))
#define _SELECT_NHOP(_nh, _flowid) \
(_NH2MP(_nh))->nhops[(_flowid) % (_NH2MP(_nh))->mp_size]
#define _RT_SELECT_NHOP(_nh, _flowid) \
((!NH_IS_MULTIPATH(_nh)) ? (_nh) : _SELECT_NHOP(_nh, _flowid))
#define RT_SELECT_NHOP(_rt, _flowid) _RT_SELECT_NHOP((_rt)->rt_nhop, _flowid)
/* rte<>nhop translation */
static inline uint16_t
fib_rte_to_nh_flags(int rt_flags)
{
uint16_t res;
res = (rt_flags & RTF_REJECT) ? NHF_REJECT : 0;
res |= (rt_flags & RTF_HOST) ? NHF_HOST : 0;
res |= (rt_flags & RTF_BLACKHOLE) ? NHF_BLACKHOLE : 0;
res |= (rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) ? NHF_REDIRECT : 0;
res |= (rt_flags & RTF_BROADCAST) ? NHF_BROADCAST : 0;
res |= (rt_flags & RTF_GATEWAY) ? NHF_GATEWAY : 0;
return (res);
}
void tmproutes_update(struct rib_head *rnh, struct rtentry *rt);
void tmproutes_init(struct rib_head *rh);
void tmproutes_destroy(struct rib_head *rh);
#endif
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