freebsd-dev/sys/netinet/in_fib.c
Gleb Smirnoff 6ca363eb7b Existense of PCB route caching doesn't allow us to use new fast route
lookup KPI in ip_output() like it is already used in ip_forward().
However, when there is no PCB provided we can use fast KPI, gaining
performance advantage.

Typical case when ip_output() is called without a PCB pointer is a
sendto(2) on a not connected UDP socket. In practice DNS servers do
this.

Reviewed by:	melifaro
Differential Revision:	https://reviews.freebsd.org/D19804
2019-05-08 23:39:24 +00:00

233 lines
6.8 KiB
C

/*-
* Copyright (c) 2015
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_route.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/rmlock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/route_var.h>
#include <net/vnet.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_fib.h>
#ifdef INET
static void fib4_rte_to_nh_basic(struct rtentry *rte, struct in_addr dst,
uint32_t flags, struct nhop4_basic *pnh4);
static void fib4_rte_to_nh_extended(struct rtentry *rte, struct in_addr dst,
uint32_t flags, struct nhop4_extended *pnh4);
#define RNTORT(p) ((struct rtentry *)(p))
static void
fib4_rte_to_nh_basic(struct rtentry *rte, struct in_addr dst,
uint32_t flags, struct nhop4_basic *pnh4)
{
struct sockaddr_in *gw;
if ((flags & NHR_IFAIF) != 0)
pnh4->nh_ifp = rte->rt_ifa->ifa_ifp;
else
pnh4->nh_ifp = rte->rt_ifp;
pnh4->nh_mtu = min(rte->rt_mtu, rte->rt_ifp->if_mtu);
if (rte->rt_flags & RTF_GATEWAY) {
gw = (struct sockaddr_in *)rte->rt_gateway;
pnh4->nh_addr = gw->sin_addr;
} else
pnh4->nh_addr = dst;
/* Set flags */
pnh4->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
gw = (struct sockaddr_in *)rt_key(rte);
if (gw->sin_addr.s_addr == 0)
pnh4->nh_flags |= NHF_DEFAULT;
/* TODO: Handle RTF_BROADCAST here */
}
static void
fib4_rte_to_nh_extended(struct rtentry *rte, struct in_addr dst,
uint32_t flags, struct nhop4_extended *pnh4)
{
struct sockaddr_in *gw;
if ((flags & NHR_IFAIF) != 0)
pnh4->nh_ifp = rte->rt_ifa->ifa_ifp;
else
pnh4->nh_ifp = rte->rt_ifp;
pnh4->nh_mtu = min(rte->rt_mtu, rte->rt_ifp->if_mtu);
if (rte->rt_flags & RTF_GATEWAY) {
gw = (struct sockaddr_in *)rte->rt_gateway;
pnh4->nh_addr = gw->sin_addr;
} else
pnh4->nh_addr = dst;
/* Set flags */
pnh4->nh_flags = fib_rte_to_nh_flags(rte->rt_flags);
gw = (struct sockaddr_in *)rt_key(rte);
if (gw->sin_addr.s_addr == 0)
pnh4->nh_flags |= NHF_DEFAULT;
pnh4->nh_ia = ifatoia(rte->rt_ifa);
pnh4->nh_src = IA_SIN(pnh4->nh_ia)->sin_addr;
}
/*
* Performs IPv4 route table lookup on @dst. Returns 0 on success.
* Stores nexthop info provided @pnh4 structure.
* Note that
* - nh_ifp cannot be safely dereferenced
* - nh_ifp represents logical transmit interface (rt_ifp) (e.g. if
* looking up address on interface "ix0" pointer to "lo0" interface
* will be returned instead of "ix0")
* - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
* - howewer mtu from "transmit" interface will be returned.
*/
int
fib4_lookup_nh_basic(uint32_t fibnum, struct in_addr dst, uint32_t flags,
uint32_t flowid, struct nhop4_basic *pnh4)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct sockaddr_in sin;
struct rtentry *rte;
KASSERT((fibnum < rt_numfibs), ("fib4_lookup_nh_basic: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET);
if (rh == NULL)
return (ENOENT);
/* Prepare lookup key */
memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_addr = dst;
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rte = RNTORT(rn);
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(rte->rt_ifp)) {
fib4_rte_to_nh_basic(rte, dst, flags, pnh4);
RIB_RUNLOCK(rh);
return (0);
}
}
RIB_RUNLOCK(rh);
return (ENOENT);
}
/*
* Performs IPv4 route table lookup on @dst. Returns 0 on success.
* Stores extende nexthop info provided @pnh4 structure.
* Note that
* - nh_ifp cannot be safely dereferenced unless NHR_REF is specified.
* - in that case you need to call fib4_free_nh_ext()
* - nh_ifp represents logical transmit interface (rt_ifp) (e.g. if
* looking up address of interface "ix0" pointer to "lo0" interface
* will be returned instead of "ix0")
* - nh_ifp represents "address" interface if NHR_IFAIF flag is passed
* - howewer mtu from "transmit" interface will be returned.
*/
int
fib4_lookup_nh_ext(uint32_t fibnum, struct in_addr dst, uint32_t flags,
uint32_t flowid, struct nhop4_extended *pnh4)
{
RIB_RLOCK_TRACKER;
struct rib_head *rh;
struct radix_node *rn;
struct sockaddr_in sin;
struct rtentry *rte;
KASSERT((fibnum < rt_numfibs), ("fib4_lookup_nh_ext: bad fibnum"));
rh = rt_tables_get_rnh(fibnum, AF_INET);
if (rh == NULL)
return (ENOENT);
/* Prepare lookup key */
memset(&sin, 0, sizeof(sin));
sin.sin_len = sizeof(struct sockaddr_in);
sin.sin_addr = dst;
RIB_RLOCK(rh);
rn = rh->rnh_matchaddr((void *)&sin, &rh->head);
if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) {
rte = RNTORT(rn);
#ifdef RADIX_MPATH
rte = rt_mpath_select(rte, flowid);
if (rte == NULL) {
RIB_RUNLOCK(rh);
return (ENOENT);
}
#endif
/* Ensure route & ifp is UP */
if (RT_LINK_IS_UP(rte->rt_ifp)) {
fib4_rte_to_nh_extended(rte, dst, flags, pnh4);
if ((flags & NHR_REF) != 0) {
/* TODO: lwref on egress ifp's ? */
}
RIB_RUNLOCK(rh);
return (0);
}
}
RIB_RUNLOCK(rh);
return (ENOENT);
}
void
fib4_free_nh_ext(uint32_t fibnum, struct nhop4_extended *pnh4)
{
}
#endif