1 /*- 2 * Copyright (c) 2015 3 * Alexander V. Chernikov <melifaro@FreeBSD.org> 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_inet.h" 34 #include "opt_inet6.h" 35 #include "opt_route.h" 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/lock.h> 40 #include <sys/rmlock.h> 41 #include <sys/malloc.h> 42 #include <sys/mbuf.h> 43 #include <sys/socket.h> 44 #include <sys/sysctl.h> 45 #include <sys/kernel.h> 46 47 #include <net/if.h> 48 #include <net/if_var.h> 49 #include <net/if_dl.h> 50 #include <net/route.h> 51 #include <net/route/route_ctl.h> 52 #include <net/route/route_var.h> 53 #include <net/route/nhop.h> 54 #include <net/toeplitz.h> 55 #include <net/vnet.h> 56 57 #include <netinet/in.h> 58 #include <netinet/in_var.h> 59 #include <netinet/ip_mroute.h> 60 #include <netinet/ip6.h> 61 #include <netinet6/in6_fib.h> 62 #include <netinet6/in6_var.h> 63 #include <netinet6/nd6.h> 64 #include <netinet6/scope6_var.h> 65 66 #include <net/if_types.h> 67 68 #ifdef INET6 69 70 CHK_STRUCT_ROUTE_COMPAT(struct route_in6, ro_dst); 71 72 #ifdef ROUTE_MPATH 73 struct _hash_5tuple_ipv6 { 74 struct in6_addr src; 75 struct in6_addr dst; 76 unsigned short src_port; 77 unsigned short dst_port; 78 char proto; 79 char spare[3]; 80 }; 81 _Static_assert(sizeof(struct _hash_5tuple_ipv6) == 40, 82 "_hash_5tuple_ipv6 size is wrong"); 83 84 uint32_t 85 fib6_calc_software_hash(const struct in6_addr *src, const struct in6_addr *dst, 86 unsigned short src_port, unsigned short dst_port, char proto, 87 uint32_t *phashtype) 88 { 89 struct _hash_5tuple_ipv6 data; 90 91 data.src = *src; 92 data.dst = *dst; 93 data.src_port = src_port; 94 data.dst_port = dst_port; 95 data.proto = proto; 96 data.spare[0] = data.spare[1] = data.spare[2] = 0; 97 98 *phashtype = M_HASHTYPE_OPAQUE_HASH; 99 100 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key, 101 sizeof(data), (uint8_t *)&data)); 102 } 103 #endif 104 105 /* 106 * Looks up path in fib @fibnum specified by @dst. 107 * Assumes scope is deembedded and provided in @scopeid. 108 * 109 * Returns path nexthop on success. Nexthop is safe to use 110 * within the current network epoch. If longer lifetime is required, 111 * one needs to pass NHR_REF as a flag. This will return referenced 112 * nexthop. 113 */ 114 struct nhop_object * 115 fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6, 116 uint32_t scopeid, uint32_t flags, uint32_t flowid) 117 { 118 RIB_RLOCK_TRACKER; 119 struct rib_head *rh; 120 struct radix_node *rn; 121 struct nhop_object *nh; 122 123 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum")); 124 rh = rt_tables_get_rnh(fibnum, AF_INET6); 125 if (rh == NULL) 126 return (NULL); 127 128 struct sockaddr_in6 sin6 = { 129 .sin6_len = sizeof(struct sockaddr_in6), 130 .sin6_addr = *dst6, 131 }; 132 133 /* Assume scopeid is valid and embed it directly */ 134 if (IN6_IS_SCOPE_LINKLOCAL(dst6)) 135 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff); 136 137 RIB_RLOCK(rh); 138 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head); 139 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 140 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid); 141 /* Ensure route & ifp is UP */ 142 if (RT_LINK_IS_UP(nh->nh_ifp)) { 143 if (flags & NHR_REF) 144 nhop_ref_object(nh); 145 RIB_RUNLOCK(rh); 146 return (nh); 147 } 148 } 149 RIB_RUNLOCK(rh); 150 151 RTSTAT_INC(rts_unreach); 152 return (NULL); 153 } 154 155 inline static int 156 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags, 157 const struct ifnet *src_if) 158 { 159 160 if (src_if != NULL && nh->nh_aifp == src_if) { 161 return (1); 162 } 163 if (src_if == NULL) { 164 if ((flags & NHR_NODEFAULT) == 0) 165 return (1); 166 else if ((nh->nh_flags & NHF_DEFAULT) == 0) 167 return (1); 168 } 169 170 return (0); 171 } 172 173 static int 174 check_urpf(struct nhop_object *nh, uint32_t flags, 175 const struct ifnet *src_if) 176 { 177 #ifdef ROUTE_MPATH 178 if (NH_IS_NHGRP(nh)) { 179 struct weightened_nhop *wn; 180 uint32_t num_nhops; 181 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops); 182 for (int i = 0; i < num_nhops; i++) { 183 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0) 184 return (1); 185 } 186 return (0); 187 } else 188 #endif 189 return (check_urpf_nhop(nh, flags, src_if)); 190 } 191 192 static struct nhop_object * 193 lookup_nhop(uint32_t fibnum, const struct in6_addr *dst6, 194 uint32_t scopeid) 195 { 196 RIB_RLOCK_TRACKER; 197 struct rib_head *rh; 198 struct radix_node *rn; 199 struct nhop_object *nh; 200 201 KASSERT((fibnum < rt_numfibs), ("fib6_check_urpf: bad fibnum")); 202 rh = rt_tables_get_rnh(fibnum, AF_INET6); 203 if (rh == NULL) 204 return (NULL); 205 206 /* Prepare lookup key */ 207 struct sockaddr_in6 sin6 = { 208 .sin6_len = sizeof(struct sockaddr_in6), 209 .sin6_addr = *dst6, 210 }; 211 212 /* Assume scopeid is valid and embed it directly */ 213 if (IN6_IS_SCOPE_LINKLOCAL(dst6)) 214 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff); 215 216 nh = NULL; 217 RIB_RLOCK(rh); 218 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head); 219 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) 220 nh = RNTORT(rn)->rt_nhop; 221 RIB_RUNLOCK(rh); 222 223 return (nh); 224 } 225 226 /* 227 * Performs reverse path forwarding lookup. 228 * If @src_if is non-zero, verifies that at least 1 path goes via 229 * this interface. 230 * If @src_if is zero, verifies that route exist. 231 * if @flags contains NHR_NOTDEFAULT, do not consider default route. 232 * 233 * Returns 1 if route matching conditions is found, 0 otherwise. 234 */ 235 int 236 fib6_check_urpf(uint32_t fibnum, const struct in6_addr *dst6, 237 uint32_t scopeid, uint32_t flags, const struct ifnet *src_if) 238 { 239 struct nhop_object *nh; 240 241 nh = lookup_nhop(fibnum, dst6, scopeid); 242 if (nh != NULL) 243 return (check_urpf(nh, flags, src_if)); 244 return (0); 245 } 246 247 /* 248 * Function returning prefix match data along with the nexthop data. 249 * Intended to be used by the control plane code. 250 * Supported flags: 251 * NHR_UNLOCKED: do not lock radix during lookup. 252 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry 253 * and nexthop are safe to use within current epoch. Note: 254 * Note: rnd_nhop can actually be the nexthop group. 255 */ 256 struct rtentry * 257 fib6_lookup_rt(uint32_t fibnum, const struct in6_addr *dst6, 258 uint32_t scopeid, uint32_t flags, struct route_nhop_data *rnd) 259 { 260 RIB_RLOCK_TRACKER; 261 struct rib_head *rh; 262 struct radix_node *rn; 263 struct rtentry *rt; 264 265 KASSERT((fibnum < rt_numfibs), ("fib6_lookup: bad fibnum")); 266 rh = rt_tables_get_rnh(fibnum, AF_INET6); 267 if (rh == NULL) 268 return (NULL); 269 270 struct sockaddr_in6 sin6 = { 271 .sin6_len = sizeof(struct sockaddr_in6), 272 .sin6_addr = *dst6, 273 }; 274 275 /* Assume scopeid is valid and embed it directly */ 276 if (IN6_IS_SCOPE_LINKLOCAL(dst6)) 277 sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff); 278 279 rt = NULL; 280 if (!(flags & NHR_UNLOCKED)) 281 RIB_RLOCK(rh); 282 rn = rh->rnh_matchaddr((void *)&sin6, &rh->head); 283 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 284 rt = (struct rtentry *)rn; 285 rnd->rnd_nhop = rt->rt_nhop; 286 rnd->rnd_weight = rt->rt_weight; 287 } 288 if (!(flags & NHR_UNLOCKED)) 289 RIB_RUNLOCK(rh); 290 291 return (rt); 292 } 293 294 struct nhop_object * 295 fib6_lookup_debugnet(uint32_t fibnum, const struct in6_addr *dst6, 296 uint32_t scopeid, uint32_t flags) 297 { 298 struct rtentry *rt; 299 struct route_nhop_data rnd; 300 301 rt = fib6_lookup_rt(fibnum, dst6, scopeid, NHR_UNLOCKED, &rnd); 302 if (rt != NULL) { 303 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0); 304 /* Ensure route & ifp is UP */ 305 if (RT_LINK_IS_UP(nh->nh_ifp)) 306 return (nh); 307 } 308 309 return (NULL); 310 } 311 312 #endif 313