1178168Sqingli/* $KAME: radix_mpath.c,v 1.17 2004/11/08 10:29:39 itojun Exp $ */ 2178168Sqingli 3178168Sqingli/* 4178168Sqingli * Copyright (C) 2001 WIDE Project. 5178168Sqingli * All rights reserved. 6178168Sqingli * 7178168Sqingli * Redistribution and use in source and binary forms, with or without 8178168Sqingli * modification, are permitted provided that the following conditions 9178168Sqingli * are met: 10178168Sqingli * 1. Redistributions of source code must retain the above copyright 11178168Sqingli * notice, this list of conditions and the following disclaimer. 12178168Sqingli * 2. Redistributions in binary form must reproduce the above copyright 13178168Sqingli * notice, this list of conditions and the following disclaimer in the 14178168Sqingli * documentation and/or other materials provided with the distribution. 15178168Sqingli * 3. Neither the name of the project nor the names of its contributors 16178168Sqingli * may be used to endorse or promote products derived from this software 17178168Sqingli * without specific prior written permission. 18178168Sqingli * 19178168Sqingli * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20178168Sqingli * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21178168Sqingli * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22178168Sqingli * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23178168Sqingli * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24178168Sqingli * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25178168Sqingli * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26178168Sqingli * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27178168Sqingli * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28178168Sqingli * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29178168Sqingli * SUCH DAMAGE. 30178168Sqingli * THE AUTHORS DO NOT GUARANTEE THAT THIS SOFTWARE DOES NOT INFRINGE 31178168Sqingli * ANY OTHERS' INTELLECTUAL PROPERTIES. IN NO EVENT SHALL THE AUTHORS 32178168Sqingli * BE LIABLE FOR ANY INFRINGEMENT OF ANY OTHERS' INTELLECTUAL 33178168Sqingli * PROPERTIES. 34178168Sqingli */ 35178168Sqingli 36178168Sqingli#include <sys/cdefs.h> 37178168Sqingli__FBSDID("$FreeBSD$"); 38178168Sqingli 39184681Sbz#include "opt_inet.h" 40178187Sqingli#include "opt_inet6.h" 41178187Sqingli 42178168Sqingli#include <sys/param.h> 43178168Sqingli#include <sys/systm.h> 44178168Sqingli#include <sys/malloc.h> 45178168Sqingli#include <sys/socket.h> 46178168Sqingli#include <sys/domain.h> 47178168Sqingli#include <sys/syslog.h> 48178168Sqingli#include <net/radix.h> 49178168Sqingli#include <net/radix_mpath.h> 50178168Sqingli#include <net/route.h> 51178168Sqingli#include <net/if.h> 52178168Sqingli#include <net/if_var.h> 53178168Sqingli 54178168Sqingli/* 55178168Sqingli * give some jitter to hash, to avoid synchronization between routers 56178168Sqingli */ 57184837Skmacystatic uint32_t hashjitter; 58178168Sqingli 59178168Sqingliint 60178168Sqinglirn_mpath_capable(struct radix_node_head *rnh) 61178168Sqingli{ 62178168Sqingli 63178168Sqingli return rnh->rnh_multipath; 64178168Sqingli} 65178168Sqingli 66178168Sqinglistruct radix_node * 67178168Sqinglirn_mpath_next(struct radix_node *rn) 68178168Sqingli{ 69178168Sqingli struct radix_node *next; 70178168Sqingli 71178168Sqingli if (!rn->rn_dupedkey) 72178168Sqingli return NULL; 73178168Sqingli next = rn->rn_dupedkey; 74178168Sqingli if (rn->rn_mask == next->rn_mask) 75178168Sqingli return next; 76178168Sqingli else 77178168Sqingli return NULL; 78178168Sqingli} 79178168Sqingli 80191080Skmacyuint32_t 81178168Sqinglirn_mpath_count(struct radix_node *rn) 82178168Sqingli{ 83191080Skmacy uint32_t i = 0; 84191080Skmacy struct rtentry *rt; 85191080Skmacy 86191080Skmacy while (rn != NULL) { 87191080Skmacy rt = (struct rtentry *)rn; 88263478Sglebius i += rt->rt_weight; 89191080Skmacy rn = rn_mpath_next(rn); 90191080Skmacy } 91191080Skmacy return (i); 92178168Sqingli} 93178168Sqingli 94178168Sqinglistruct rtentry * 95178168Sqinglirt_mpath_matchgate(struct rtentry *rt, struct sockaddr *gate) 96178168Sqingli{ 97178168Sqingli struct radix_node *rn; 98178168Sqingli 99225163Sqingli if (!gate || !rt->rt_gateway) 100178168Sqingli return NULL; 101178168Sqingli 102178168Sqingli /* beyond here, we use rn as the master copy */ 103178168Sqingli rn = (struct radix_node *)rt; 104178168Sqingli do { 105178168Sqingli rt = (struct rtentry *)rn; 106178168Sqingli /* 107178168Sqingli * we are removing an address alias that has 108178168Sqingli * the same prefix as another address 109178168Sqingli * we need to compare the interface address because 110178168Sqingli * rt_gateway is a special sockadd_dl structure 111178168Sqingli */ 112178168Sqingli if (rt->rt_gateway->sa_family == AF_LINK) { 113178168Sqingli if (!memcmp(rt->rt_ifa->ifa_addr, gate, gate->sa_len)) 114178168Sqingli break; 115178168Sqingli } 116265711Smelifaro 117265711Smelifaro /* 118265711Smelifaro * Check for other options: 119265711Smelifaro * 1) Routes with 'real' IPv4/IPv6 gateway 120265711Smelifaro * 2) Loopback host routes (another AF_LINK/sockadd_dl check) 121265711Smelifaro * */ 122265711Smelifaro if (rt->rt_gateway->sa_len == gate->sa_len && 123265711Smelifaro !memcmp(rt->rt_gateway, gate, gate->sa_len)) 124265711Smelifaro break; 125178168Sqingli } while ((rn = rn_mpath_next(rn)) != NULL); 126178168Sqingli 127178168Sqingli return (struct rtentry *)rn; 128178168Sqingli} 129178168Sqingli 130178168Sqingli/* 131178168Sqingli * go through the chain and unlink "rt" from the list 132178168Sqingli * the caller will free "rt" 133178168Sqingli */ 134178168Sqingliint 135178168Sqinglirt_mpath_deldup(struct rtentry *headrt, struct rtentry *rt) 136178168Sqingli{ 137178168Sqingli struct radix_node *t, *tt; 138178168Sqingli 139178168Sqingli if (!headrt || !rt) 140178168Sqingli return (0); 141178168Sqingli t = (struct radix_node *)headrt; 142178168Sqingli tt = rn_mpath_next(t); 143178168Sqingli while (tt) { 144178168Sqingli if (tt == (struct radix_node *)rt) { 145178168Sqingli t->rn_dupedkey = tt->rn_dupedkey; 146178168Sqingli tt->rn_dupedkey = NULL; 147178168Sqingli tt->rn_flags &= ~RNF_ACTIVE; 148178168Sqingli tt[1].rn_flags &= ~RNF_ACTIVE; 149178168Sqingli return (1); 150178168Sqingli } 151178168Sqingli t = tt; 152178168Sqingli tt = rn_mpath_next((struct radix_node *)t); 153178168Sqingli } 154178168Sqingli return (0); 155178168Sqingli} 156178168Sqingli 157178168Sqingli/* 158178168Sqingli * check if we have the same key/mask/gateway on the table already. 159265708Smelifaro * Assume @rt rt_key host bits are cleared according to @netmask 160178168Sqingli */ 161178168Sqingliint 162178168Sqinglirt_mpath_conflict(struct radix_node_head *rnh, struct rtentry *rt, 163178168Sqingli struct sockaddr *netmask) 164178168Sqingli{ 165178168Sqingli struct radix_node *rn, *rn1; 166178168Sqingli struct rtentry *rt1; 167178168Sqingli 168178168Sqingli rn = (struct radix_node *)rt; 169178168Sqingli rn1 = rnh->rnh_lookup(rt_key(rt), netmask, rnh); 170178168Sqingli if (!rn1 || rn1->rn_flags & RNF_ROOT) 171265708Smelifaro return (0); 172178168Sqingli 173265708Smelifaro /* key/mask are the same. compare gateway for all multipaths */ 174178168Sqingli do { 175178168Sqingli rt1 = (struct rtentry *)rn1; 176178168Sqingli 177178168Sqingli /* sanity: no use in comparing the same thing */ 178178168Sqingli if (rn1 == rn) 179178168Sqingli continue; 180178168Sqingli 181178168Sqingli if (rt1->rt_gateway->sa_family == AF_LINK) { 182178168Sqingli if (rt1->rt_ifa->ifa_addr->sa_len != rt->rt_ifa->ifa_addr->sa_len || 183178168Sqingli bcmp(rt1->rt_ifa->ifa_addr, rt->rt_ifa->ifa_addr, 184178168Sqingli rt1->rt_ifa->ifa_addr->sa_len)) 185178168Sqingli continue; 186178168Sqingli } else { 187178168Sqingli if (rt1->rt_gateway->sa_len != rt->rt_gateway->sa_len || 188178168Sqingli bcmp(rt1->rt_gateway, rt->rt_gateway, 189178168Sqingli rt1->rt_gateway->sa_len)) 190178168Sqingli continue; 191178168Sqingli } 192178168Sqingli 193178168Sqingli /* all key/mask/gateway are the same. conflicting entry. */ 194265708Smelifaro return (EEXIST); 195178168Sqingli } while ((rn1 = rn_mpath_next(rn1)) != NULL); 196178168Sqingli 197265708Smelifaro return (0); 198178168Sqingli} 199178168Sqingli 200178168Sqinglivoid 201191080Skmacyrtalloc_mpath_fib(struct route *ro, uint32_t hash, u_int fibnum) 202178168Sqingli{ 203178168Sqingli struct radix_node *rn0, *rn; 204179426Sqingli u_int32_t n; 205191080Skmacy struct rtentry *rt; 206191080Skmacy int64_t weight; 207178168Sqingli 208178168Sqingli /* 209178168Sqingli * XXX we don't attempt to lookup cached route again; what should 210178168Sqingli * be done for sendto(3) case? 211178168Sqingli */ 212204902Sqingli if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP) 213204902Sqingli && RT_LINK_IS_UP(ro->ro_rt->rt_ifp)) 214186119Sqingli return; 215186119Sqingli ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, 0, fibnum); 216178168Sqingli 217178168Sqingli /* if the route does not exist or it is not multipath, don't care */ 218178454Sqingli if (ro->ro_rt == NULL) 219178454Sqingli return; 220178454Sqingli if (rn_mpath_next((struct radix_node *)ro->ro_rt) == NULL) { 221178168Sqingli RT_UNLOCK(ro->ro_rt); 222178168Sqingli return; 223178168Sqingli } 224178168Sqingli 225178168Sqingli /* beyond here, we use rn as the master copy */ 226178168Sqingli rn0 = rn = (struct radix_node *)ro->ro_rt; 227178168Sqingli n = rn_mpath_count(rn0); 228178168Sqingli 229178168Sqingli /* gw selection by Modulo-N Hash (RFC2991) XXX need improvement? */ 230178168Sqingli hash += hashjitter; 231178168Sqingli hash %= n; 232191080Skmacy for (weight = abs((int32_t)hash), rt = ro->ro_rt; 233263478Sglebius weight >= rt->rt_weight && rn; 234263478Sglebius weight -= rt->rt_weight) { 235191080Skmacy 236178168Sqingli /* stay within the multipath routes */ 237178168Sqingli if (rn->rn_dupedkey && rn->rn_mask != rn->rn_dupedkey->rn_mask) 238178168Sqingli break; 239178168Sqingli rn = rn->rn_dupedkey; 240191080Skmacy rt = (struct rtentry *)rn; 241178168Sqingli } 242178168Sqingli /* XXX try filling rt_gwroute and avoid unreachable gw */ 243178168Sqingli 244191080Skmacy /* gw selection has failed - there must be only zero weight routes */ 245178168Sqingli if (!rn) { 246178168Sqingli RT_UNLOCK(ro->ro_rt); 247191080Skmacy ro->ro_rt = NULL; 248178168Sqingli return; 249178168Sqingli } 250191080Skmacy if (ro->ro_rt != rt) { 251191080Skmacy RTFREE_LOCKED(ro->ro_rt); 252191080Skmacy ro->ro_rt = (struct rtentry *)rn; 253191080Skmacy RT_LOCK(ro->ro_rt); 254191080Skmacy RT_ADDREF(ro->ro_rt); 255191080Skmacy 256191080Skmacy } 257178168Sqingli RT_UNLOCK(ro->ro_rt); 258178168Sqingli} 259178168Sqingli 260178168Sqingliextern int in6_inithead(void **head, int off); 261178168Sqingliextern int in_inithead(void **head, int off); 262178168Sqingli 263184681Sbz#ifdef INET 264178168Sqingliint 265178168Sqinglirn4_mpath_inithead(void **head, int off) 266178168Sqingli{ 267178168Sqingli struct radix_node_head *rnh; 268178168Sqingli 269178168Sqingli hashjitter = arc4random(); 270178168Sqingli if (in_inithead(head, off) == 1) { 271178168Sqingli rnh = (struct radix_node_head *)*head; 272178168Sqingli rnh->rnh_multipath = 1; 273178168Sqingli return 1; 274178168Sqingli } else 275178168Sqingli return 0; 276178168Sqingli} 277184681Sbz#endif 278178168Sqingli 279178183Sphk#ifdef INET6 280178168Sqingliint 281178168Sqinglirn6_mpath_inithead(void **head, int off) 282178168Sqingli{ 283178168Sqingli struct radix_node_head *rnh; 284178168Sqingli 285178168Sqingli hashjitter = arc4random(); 286178168Sqingli if (in6_inithead(head, off) == 1) { 287178168Sqingli rnh = (struct radix_node_head *)*head; 288178168Sqingli rnh->rnh_multipath = 1; 289178168Sqingli return 1; 290178168Sqingli } else 291178168Sqingli return 0; 292178168Sqingli} 293178168Sqingli 294178183Sphk#endif 295