1/* $KAME: radix_mpath.c,v 1.17 2004/11/08 10:29:39 itojun Exp $ */ 2 3/* 4 * Copyright (C) 2001 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * THE AUTHORS DO NOT GUARANTEE THAT THIS SOFTWARE DOES NOT INFRINGE 31 * ANY OTHERS' INTELLECTUAL PROPERTIES. IN NO EVENT SHALL THE AUTHORS 32 * BE LIABLE FOR ANY INFRINGEMENT OF ANY OTHERS' INTELLECTUAL 33 * PROPERTIES. 34 */ 35 36#include <sys/cdefs.h> 37__FBSDID("$FreeBSD: releng/10.3/sys/net/radix_mpath.c 265711 2014-05-08 20:41:39Z melifaro $"); 38 39#include "opt_inet.h" 40#include "opt_inet6.h" 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/malloc.h> 45#include <sys/socket.h> 46#include <sys/domain.h> 47#include <sys/syslog.h> 48#include <net/radix.h> 49#include <net/radix_mpath.h> 50#include <net/route.h> 51#include <net/if.h> 52#include <net/if_var.h> 53 54/* 55 * give some jitter to hash, to avoid synchronization between routers 56 */ 57static uint32_t hashjitter; 58 59int 60rn_mpath_capable(struct radix_node_head *rnh) 61{ 62 63 return rnh->rnh_multipath; 64} 65 66struct radix_node * 67rn_mpath_next(struct radix_node *rn) 68{ 69 struct radix_node *next; 70 71 if (!rn->rn_dupedkey) 72 return NULL; 73 next = rn->rn_dupedkey; 74 if (rn->rn_mask == next->rn_mask) 75 return next; 76 else 77 return NULL; 78} 79 80uint32_t 81rn_mpath_count(struct radix_node *rn) 82{ 83 uint32_t i = 0; 84 struct rtentry *rt; 85 86 while (rn != NULL) { 87 rt = (struct rtentry *)rn; 88 i += rt->rt_weight; 89 rn = rn_mpath_next(rn); 90 } 91 return (i); 92} 93 94struct rtentry * 95rt_mpath_matchgate(struct rtentry *rt, struct sockaddr *gate) 96{ 97 struct radix_node *rn; 98 99 if (!gate || !rt->rt_gateway) 100 return NULL; 101 102 /* beyond here, we use rn as the master copy */ 103 rn = (struct radix_node *)rt; 104 do { 105 rt = (struct rtentry *)rn; 106 /* 107 * we are removing an address alias that has 108 * the same prefix as another address 109 * we need to compare the interface address because 110 * rt_gateway is a special sockadd_dl structure 111 */ 112 if (rt->rt_gateway->sa_family == AF_LINK) { 113 if (!memcmp(rt->rt_ifa->ifa_addr, gate, gate->sa_len)) 114 break; 115 } 116 117 /* 118 * Check for other options: 119 * 1) Routes with 'real' IPv4/IPv6 gateway 120 * 2) Loopback host routes (another AF_LINK/sockadd_dl check) 121 * */ 122 if (rt->rt_gateway->sa_len == gate->sa_len && 123 !memcmp(rt->rt_gateway, gate, gate->sa_len)) 124 break; 125 } while ((rn = rn_mpath_next(rn)) != NULL); 126 127 return (struct rtentry *)rn; 128} 129 130/* 131 * go through the chain and unlink "rt" from the list 132 * the caller will free "rt" 133 */ 134int 135rt_mpath_deldup(struct rtentry *headrt, struct rtentry *rt) 136{ 137 struct radix_node *t, *tt; 138 139 if (!headrt || !rt) 140 return (0); 141 t = (struct radix_node *)headrt; 142 tt = rn_mpath_next(t); 143 while (tt) { 144 if (tt == (struct radix_node *)rt) { 145 t->rn_dupedkey = tt->rn_dupedkey; 146 tt->rn_dupedkey = NULL; 147 tt->rn_flags &= ~RNF_ACTIVE; 148 tt[1].rn_flags &= ~RNF_ACTIVE; 149 return (1); 150 } 151 t = tt; 152 tt = rn_mpath_next((struct radix_node *)t); 153 } 154 return (0); 155} 156 157/* 158 * check if we have the same key/mask/gateway on the table already. 159 * Assume @rt rt_key host bits are cleared according to @netmask 160 */ 161int 162rt_mpath_conflict(struct radix_node_head *rnh, struct rtentry *rt, 163 struct sockaddr *netmask) 164{ 165 struct radix_node *rn, *rn1; 166 struct rtentry *rt1; 167 168 rn = (struct radix_node *)rt; 169 rn1 = rnh->rnh_lookup(rt_key(rt), netmask, rnh); 170 if (!rn1 || rn1->rn_flags & RNF_ROOT) 171 return (0); 172 173 /* key/mask are the same. compare gateway for all multipaths */ 174 do { 175 rt1 = (struct rtentry *)rn1; 176 177 /* sanity: no use in comparing the same thing */ 178 if (rn1 == rn) 179 continue; 180 181 if (rt1->rt_gateway->sa_family == AF_LINK) { 182 if (rt1->rt_ifa->ifa_addr->sa_len != rt->rt_ifa->ifa_addr->sa_len || 183 bcmp(rt1->rt_ifa->ifa_addr, rt->rt_ifa->ifa_addr, 184 rt1->rt_ifa->ifa_addr->sa_len)) 185 continue; 186 } else { 187 if (rt1->rt_gateway->sa_len != rt->rt_gateway->sa_len || 188 bcmp(rt1->rt_gateway, rt->rt_gateway, 189 rt1->rt_gateway->sa_len)) 190 continue; 191 } 192 193 /* all key/mask/gateway are the same. conflicting entry. */ 194 return (EEXIST); 195 } while ((rn1 = rn_mpath_next(rn1)) != NULL); 196 197 return (0); 198} 199 200void 201rtalloc_mpath_fib(struct route *ro, uint32_t hash, u_int fibnum) 202{ 203 struct radix_node *rn0, *rn; 204 u_int32_t n; 205 struct rtentry *rt; 206 int64_t weight; 207 208 /* 209 * XXX we don't attempt to lookup cached route again; what should 210 * be done for sendto(3) case? 211 */ 212 if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP) 213 && RT_LINK_IS_UP(ro->ro_rt->rt_ifp)) 214 return; 215 ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, 0, fibnum); 216 217 /* if the route does not exist or it is not multipath, don't care */ 218 if (ro->ro_rt == NULL) 219 return; 220 if (rn_mpath_next((struct radix_node *)ro->ro_rt) == NULL) { 221 RT_UNLOCK(ro->ro_rt); 222 return; 223 } 224 225 /* beyond here, we use rn as the master copy */ 226 rn0 = rn = (struct radix_node *)ro->ro_rt; 227 n = rn_mpath_count(rn0); 228 229 /* gw selection by Modulo-N Hash (RFC2991) XXX need improvement? */ 230 hash += hashjitter; 231 hash %= n; 232 for (weight = abs((int32_t)hash), rt = ro->ro_rt; 233 weight >= rt->rt_weight && rn; 234 weight -= rt->rt_weight) { 235 236 /* stay within the multipath routes */ 237 if (rn->rn_dupedkey && rn->rn_mask != rn->rn_dupedkey->rn_mask) 238 break; 239 rn = rn->rn_dupedkey; 240 rt = (struct rtentry *)rn; 241 } 242 /* XXX try filling rt_gwroute and avoid unreachable gw */ 243 244 /* gw selection has failed - there must be only zero weight routes */ 245 if (!rn) { 246 RT_UNLOCK(ro->ro_rt); 247 ro->ro_rt = NULL; 248 return; 249 } 250 if (ro->ro_rt != rt) { 251 RTFREE_LOCKED(ro->ro_rt); 252 ro->ro_rt = (struct rtentry *)rn; 253 RT_LOCK(ro->ro_rt); 254 RT_ADDREF(ro->ro_rt); 255 256 } 257 RT_UNLOCK(ro->ro_rt); 258} 259 260extern int in6_inithead(void **head, int off); 261extern int in_inithead(void **head, int off); 262 263#ifdef INET 264int 265rn4_mpath_inithead(void **head, int off) 266{ 267 struct radix_node_head *rnh; 268 269 hashjitter = arc4random(); 270 if (in_inithead(head, off) == 1) { 271 rnh = (struct radix_node_head *)*head; 272 rnh->rnh_multipath = 1; 273 return 1; 274 } else 275 return 0; 276} 277#endif 278 279#ifdef INET6 280int 281rn6_mpath_inithead(void **head, int off) 282{ 283 struct radix_node_head *rnh; 284 285 hashjitter = arc4random(); 286 if (in6_inithead(head, off) == 1) { 287 rnh = (struct radix_node_head *)*head; 288 rnh->rnh_multipath = 1; 289 return 1; 290 } else 291 return 0; 292} 293 294#endif 295