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; 88191080Skmacy i += rt->rt_rmx.rmx_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 } else { 116178168Sqingli if (rt->rt_gateway->sa_len == gate->sa_len && 117178168Sqingli !memcmp(rt->rt_gateway, gate, gate->sa_len)) 118178168Sqingli break; 119178168Sqingli } 120178168Sqingli } while ((rn = rn_mpath_next(rn)) != NULL); 121178168Sqingli 122178168Sqingli return (struct rtentry *)rn; 123178168Sqingli} 124178168Sqingli 125178168Sqingli/* 126178168Sqingli * go through the chain and unlink "rt" from the list 127178168Sqingli * the caller will free "rt" 128178168Sqingli */ 129178168Sqingliint 130178168Sqinglirt_mpath_deldup(struct rtentry *headrt, struct rtentry *rt) 131178168Sqingli{ 132178168Sqingli struct radix_node *t, *tt; 133178168Sqingli 134178168Sqingli if (!headrt || !rt) 135178168Sqingli return (0); 136178168Sqingli t = (struct radix_node *)headrt; 137178168Sqingli tt = rn_mpath_next(t); 138178168Sqingli while (tt) { 139178168Sqingli if (tt == (struct radix_node *)rt) { 140178168Sqingli t->rn_dupedkey = tt->rn_dupedkey; 141178168Sqingli tt->rn_dupedkey = NULL; 142178168Sqingli tt->rn_flags &= ~RNF_ACTIVE; 143178168Sqingli tt[1].rn_flags &= ~RNF_ACTIVE; 144178168Sqingli return (1); 145178168Sqingli } 146178168Sqingli t = tt; 147178168Sqingli tt = rn_mpath_next((struct radix_node *)t); 148178168Sqingli } 149178168Sqingli return (0); 150178168Sqingli} 151178168Sqingli 152178168Sqingli/* 153178168Sqingli * check if we have the same key/mask/gateway on the table already. 154178168Sqingli */ 155178168Sqingliint 156178168Sqinglirt_mpath_conflict(struct radix_node_head *rnh, struct rtentry *rt, 157178168Sqingli struct sockaddr *netmask) 158178168Sqingli{ 159178168Sqingli struct radix_node *rn, *rn1; 160178168Sqingli struct rtentry *rt1; 161178168Sqingli char *p, *q, *eq; 162178168Sqingli int same, l, skip; 163178168Sqingli 164178168Sqingli rn = (struct radix_node *)rt; 165178168Sqingli rn1 = rnh->rnh_lookup(rt_key(rt), netmask, rnh); 166178168Sqingli if (!rn1 || rn1->rn_flags & RNF_ROOT) 167178168Sqingli return 0; 168178168Sqingli 169178168Sqingli /* 170178168Sqingli * unlike other functions we have in this file, we have to check 171178168Sqingli * all key/mask/gateway as rnh_lookup can match less specific entry. 172178168Sqingli */ 173178168Sqingli rt1 = (struct rtentry *)rn1; 174178168Sqingli 175178168Sqingli /* compare key. */ 176178168Sqingli if (rt_key(rt1)->sa_len != rt_key(rt)->sa_len || 177178168Sqingli bcmp(rt_key(rt1), rt_key(rt), rt_key(rt1)->sa_len)) 178178168Sqingli goto different; 179178168Sqingli 180178168Sqingli /* key was the same. compare netmask. hairy... */ 181178168Sqingli if (rt_mask(rt1) && netmask) { 182178168Sqingli skip = rnh->rnh_treetop->rn_offset; 183178168Sqingli if (rt_mask(rt1)->sa_len > netmask->sa_len) { 184178168Sqingli /* 185178168Sqingli * as rt_mask(rt1) is made optimal by radix.c, 186178168Sqingli * there must be some 1-bits on rt_mask(rt1) 187178168Sqingli * after netmask->sa_len. therefore, in 188178168Sqingli * this case, the entries are different. 189178168Sqingli */ 190178168Sqingli if (rt_mask(rt1)->sa_len > skip) 191178168Sqingli goto different; 192178168Sqingli else { 193178168Sqingli /* no bits to compare, i.e. same*/ 194178168Sqingli goto maskmatched; 195178168Sqingli } 196178168Sqingli } 197178168Sqingli 198178168Sqingli l = rt_mask(rt1)->sa_len; 199178168Sqingli if (skip > l) { 200178168Sqingli /* no bits to compare, i.e. same */ 201178168Sqingli goto maskmatched; 202178168Sqingli } 203178168Sqingli p = (char *)rt_mask(rt1); 204178168Sqingli q = (char *)netmask; 205178168Sqingli if (bcmp(p + skip, q + skip, l - skip)) 206178168Sqingli goto different; 207178168Sqingli /* 208178168Sqingli * need to go through all the bit, as netmask is not 209178168Sqingli * optimal and can contain trailing 0s 210178168Sqingli */ 211178168Sqingli eq = (char *)netmask + netmask->sa_len; 212178168Sqingli q += l; 213178168Sqingli same = 1; 214178168Sqingli while (eq > q) 215178168Sqingli if (*q++) { 216178168Sqingli same = 0; 217178168Sqingli break; 218178168Sqingli } 219178168Sqingli if (!same) 220178168Sqingli goto different; 221178168Sqingli } else if (!rt_mask(rt1) && !netmask) 222178168Sqingli ; /* no mask to compare, i.e. same */ 223178168Sqingli else { 224178168Sqingli /* one has mask and the other does not, different */ 225178168Sqingli goto different; 226178168Sqingli } 227178168Sqingli 228178168Sqinglimaskmatched: 229178168Sqingli 230178168Sqingli /* key/mask were the same. compare gateway for all multipaths */ 231178168Sqingli do { 232178168Sqingli rt1 = (struct rtentry *)rn1; 233178168Sqingli 234178168Sqingli /* sanity: no use in comparing the same thing */ 235178168Sqingli if (rn1 == rn) 236178168Sqingli continue; 237178168Sqingli 238178168Sqingli if (rt1->rt_gateway->sa_family == AF_LINK) { 239178168Sqingli if (rt1->rt_ifa->ifa_addr->sa_len != rt->rt_ifa->ifa_addr->sa_len || 240178168Sqingli bcmp(rt1->rt_ifa->ifa_addr, rt->rt_ifa->ifa_addr, 241178168Sqingli rt1->rt_ifa->ifa_addr->sa_len)) 242178168Sqingli continue; 243178168Sqingli } else { 244178168Sqingli if (rt1->rt_gateway->sa_len != rt->rt_gateway->sa_len || 245178168Sqingli bcmp(rt1->rt_gateway, rt->rt_gateway, 246178168Sqingli rt1->rt_gateway->sa_len)) 247178168Sqingli continue; 248178168Sqingli } 249178168Sqingli 250178168Sqingli /* all key/mask/gateway are the same. conflicting entry. */ 251178168Sqingli return EEXIST; 252178168Sqingli } while ((rn1 = rn_mpath_next(rn1)) != NULL); 253178168Sqingli 254178168Sqinglidifferent: 255178168Sqingli return 0; 256178168Sqingli} 257178168Sqingli 258178168Sqinglivoid 259191080Skmacyrtalloc_mpath_fib(struct route *ro, uint32_t hash, u_int fibnum) 260178168Sqingli{ 261178168Sqingli struct radix_node *rn0, *rn; 262179426Sqingli u_int32_t n; 263191080Skmacy struct rtentry *rt; 264191080Skmacy int64_t weight; 265178168Sqingli 266178168Sqingli /* 267178168Sqingli * XXX we don't attempt to lookup cached route again; what should 268178168Sqingli * be done for sendto(3) case? 269178168Sqingli */ 270204902Sqingli if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP) 271204902Sqingli && RT_LINK_IS_UP(ro->ro_rt->rt_ifp)) 272186119Sqingli return; 273186119Sqingli ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, 0, fibnum); 274178168Sqingli 275178168Sqingli /* if the route does not exist or it is not multipath, don't care */ 276178454Sqingli if (ro->ro_rt == NULL) 277178454Sqingli return; 278178454Sqingli if (rn_mpath_next((struct radix_node *)ro->ro_rt) == NULL) { 279178168Sqingli RT_UNLOCK(ro->ro_rt); 280178168Sqingli return; 281178168Sqingli } 282178168Sqingli 283178168Sqingli /* beyond here, we use rn as the master copy */ 284178168Sqingli rn0 = rn = (struct radix_node *)ro->ro_rt; 285178168Sqingli n = rn_mpath_count(rn0); 286178168Sqingli 287178168Sqingli /* gw selection by Modulo-N Hash (RFC2991) XXX need improvement? */ 288178168Sqingli hash += hashjitter; 289178168Sqingli hash %= n; 290191080Skmacy for (weight = abs((int32_t)hash), rt = ro->ro_rt; 291191080Skmacy weight >= rt->rt_rmx.rmx_weight && rn; 292191080Skmacy weight -= rt->rt_rmx.rmx_weight) { 293191080Skmacy 294178168Sqingli /* stay within the multipath routes */ 295178168Sqingli if (rn->rn_dupedkey && rn->rn_mask != rn->rn_dupedkey->rn_mask) 296178168Sqingli break; 297178168Sqingli rn = rn->rn_dupedkey; 298191080Skmacy rt = (struct rtentry *)rn; 299178168Sqingli } 300178168Sqingli /* XXX try filling rt_gwroute and avoid unreachable gw */ 301178168Sqingli 302191080Skmacy /* gw selection has failed - there must be only zero weight routes */ 303178168Sqingli if (!rn) { 304178168Sqingli RT_UNLOCK(ro->ro_rt); 305191080Skmacy ro->ro_rt = NULL; 306178168Sqingli return; 307178168Sqingli } 308191080Skmacy if (ro->ro_rt != rt) { 309191080Skmacy RTFREE_LOCKED(ro->ro_rt); 310191080Skmacy ro->ro_rt = (struct rtentry *)rn; 311191080Skmacy RT_LOCK(ro->ro_rt); 312191080Skmacy RT_ADDREF(ro->ro_rt); 313191080Skmacy 314191080Skmacy } 315178168Sqingli RT_UNLOCK(ro->ro_rt); 316178168Sqingli} 317178168Sqingli 318178168Sqingliextern int in6_inithead(void **head, int off); 319178168Sqingliextern int in_inithead(void **head, int off); 320178168Sqingli 321184681Sbz#ifdef INET 322178168Sqingliint 323178168Sqinglirn4_mpath_inithead(void **head, int off) 324178168Sqingli{ 325178168Sqingli struct radix_node_head *rnh; 326178168Sqingli 327178168Sqingli hashjitter = arc4random(); 328178168Sqingli if (in_inithead(head, off) == 1) { 329178168Sqingli rnh = (struct radix_node_head *)*head; 330178168Sqingli rnh->rnh_multipath = 1; 331178168Sqingli return 1; 332178168Sqingli } else 333178168Sqingli return 0; 334178168Sqingli} 335184681Sbz#endif 336178168Sqingli 337178183Sphk#ifdef INET6 338178168Sqingliint 339178168Sqinglirn6_mpath_inithead(void **head, int off) 340178168Sqingli{ 341178168Sqingli struct radix_node_head *rnh; 342178168Sqingli 343178168Sqingli hashjitter = arc4random(); 344178168Sqingli if (in6_inithead(head, off) == 1) { 345178168Sqingli rnh = (struct radix_node_head *)*head; 346178168Sqingli rnh->rnh_multipath = 1; 347178168Sqingli return 1; 348178168Sqingli } else 349178168Sqingli return 0; 350178168Sqingli} 351178168Sqingli 352178183Sphk#endif 353