freebsd-dev/sys/net/route_var.h
Alexander V. Chernikov 34a5582c47 Bring back redirect route expiration.
Redirect (and temporal) route expiration was broken a while ago.
This change brings route expiration back, with unified IPv4/IPv6 handling code.

It introduces net.inet.icmp.redirtimeout sysctl, allowing to set
 an expiration time for redirected routes. It defaults to 10 minutes,
 analogues with net.inet6.icmp6.redirtimeout.

Implementation uses separate file, route_temporal.c, as route.c is already
 bloated with tons of different functions.
Internally, expiration is implemented as an per-rnh callout scheduled when
 route with non-zero rt_expire time is added or rt_expire is changed.
 It does not add any overhead when no temporal routes are present.

Callout traverses entire routing tree under wlock, scheduling expired routes
 for deletion and calculating the next time it needs to be run. The rationale
 for such implemention is the following: typically workloads requiring large
 amount of routes have redirects turned off already, while the systems with
 small amount of routes will not inhibit large overhead during tree traversal.

This changes also fixes netstat -rn display of route expiration time, which
 has been broken since the conversion from kread() to sysctl.

Reviewed by:	bz
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D23075
2020-01-22 13:53:18 +00:00

113 lines
4.8 KiB
C

/*-
* 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_
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 */
rn_close_t *rnh_close; /*do something when the last ref drops*/
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 */
};
#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)
/* 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_rt) \
_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);
/* 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