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_route.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/lock.h> 39 #include <sys/rmlock.h> 40 #include <sys/malloc.h> 41 #include <sys/mbuf.h> 42 #include <sys/socket.h> 43 #include <sys/sysctl.h> 44 #include <sys/kernel.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_dl.h> 49 #include <net/route.h> 50 #include <net/route/route_ctl.h> 51 #include <net/route/route_var.h> 52 #include <net/route/fib_algo.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/in_fib.h> 60 61 #ifdef INET 62 63 /* Verify struct route compatibility */ 64 /* Assert 'struct route_in' is compatible with 'struct route' */ 65 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4); 66 67 #ifdef FIB_ALGO 68 VNET_DEFINE(struct fib_dp *, inet_dp); 69 #endif 70 71 #ifdef ROUTE_MPATH 72 struct _hash_5tuple_ipv4 { 73 struct in_addr src; 74 struct in_addr dst; 75 unsigned short src_port; 76 unsigned short dst_port; 77 char proto; 78 char spare[3]; 79 }; 80 _Static_assert(sizeof(struct _hash_5tuple_ipv4) == 16, 81 "_hash_5tuple_ipv4 size is wrong"); 82 83 uint32_t 84 fib4_calc_software_hash(struct in_addr src, struct in_addr dst, 85 unsigned short src_port, unsigned short dst_port, char proto, 86 uint32_t *phashtype) 87 { 88 struct _hash_5tuple_ipv4 data; 89 90 data.src = src; 91 data.dst = dst; 92 data.src_port = src_port; 93 data.dst_port = dst_port; 94 data.proto = proto; 95 data.spare[0] = data.spare[1] = data.spare[2] = 0; 96 97 *phashtype = M_HASHTYPE_OPAQUE; 98 99 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key, 100 sizeof(data), (uint8_t *)&data)); 101 } 102 #endif 103 104 /* 105 * Looks up path in fib @fibnum specified by @dst. 106 * Returns path nexthop on success. Nexthop is safe to use 107 * within the current network epoch. If longer lifetime is required, 108 * one needs to pass NHR_REF as a flag. This will return referenced 109 * nexthop. 110 */ 111 #ifdef FIB_ALGO 112 struct nhop_object * 113 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 114 uint32_t flags, uint32_t flowid) 115 { 116 struct nhop_object *nh; 117 struct fib_dp *dp = &V_inet_dp[fibnum]; 118 struct flm_lookup_key key = {.addr4 = dst }; 119 120 nh = dp->f(dp->arg, key, scopeid); 121 if (nh != NULL) { 122 nh = nhop_select(nh, flowid); 123 /* Ensure route & ifp is UP */ 124 if (RT_LINK_IS_UP(nh->nh_ifp)) { 125 if (flags & NHR_REF) 126 nhop_ref_object(nh); 127 return (nh); 128 } 129 } 130 RTSTAT_INC(rts_unreach); 131 return (NULL); 132 } 133 #else 134 struct nhop_object * 135 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 136 uint32_t flags, uint32_t flowid) 137 { 138 RIB_RLOCK_TRACKER; 139 struct rib_head *rh; 140 struct radix_node *rn; 141 struct nhop_object *nh; 142 143 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum")); 144 rh = rt_tables_get_rnh(fibnum, AF_INET); 145 if (rh == NULL) 146 return (NULL); 147 148 /* Prepare lookup key */ 149 struct sockaddr_in sin4 = { 150 .sin_family = AF_INET, 151 .sin_len = sizeof(struct sockaddr_in), 152 .sin_addr = dst, 153 }; 154 155 nh = NULL; 156 RIB_RLOCK(rh); 157 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 158 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 159 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid); 160 /* Ensure route & ifp is UP */ 161 if (RT_LINK_IS_UP(nh->nh_ifp)) { 162 if (flags & NHR_REF) 163 nhop_ref_object(nh); 164 RIB_RUNLOCK(rh); 165 return (nh); 166 } 167 } 168 RIB_RUNLOCK(rh); 169 170 RTSTAT_INC(rts_unreach); 171 return (NULL); 172 } 173 #endif 174 175 inline static int 176 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags, 177 const struct ifnet *src_if) 178 { 179 180 if (src_if != NULL && nh->nh_aifp == src_if) { 181 return (1); 182 } 183 if (src_if == NULL) { 184 if ((flags & NHR_NODEFAULT) == 0) 185 return (1); 186 else if ((nh->nh_flags & NHF_DEFAULT) == 0) 187 return (1); 188 } 189 190 return (0); 191 } 192 193 static int 194 check_urpf(struct nhop_object *nh, uint32_t flags, 195 const struct ifnet *src_if) 196 { 197 #ifdef ROUTE_MPATH 198 if (NH_IS_NHGRP(nh)) { 199 const struct weightened_nhop *wn; 200 uint32_t num_nhops; 201 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops); 202 for (int i = 0; i < num_nhops; i++) { 203 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0) 204 return (1); 205 } 206 return (0); 207 } else 208 #endif 209 return (check_urpf_nhop(nh, flags, src_if)); 210 } 211 212 #ifndef FIB_ALGO 213 static struct nhop_object * 214 lookup_nhop(uint32_t fibnum, struct in_addr dst, uint32_t scopeid) 215 { 216 RIB_RLOCK_TRACKER; 217 struct rib_head *rh; 218 struct radix_node *rn; 219 struct nhop_object *nh; 220 221 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum")); 222 rh = rt_tables_get_rnh(fibnum, AF_INET); 223 if (rh == NULL) 224 return (NULL); 225 226 /* Prepare lookup key */ 227 struct sockaddr_in sin4; 228 memset(&sin4, 0, sizeof(sin4)); 229 sin4.sin_len = sizeof(struct sockaddr_in); 230 sin4.sin_addr = dst; 231 232 nh = NULL; 233 RIB_RLOCK(rh); 234 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 235 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) 236 nh = RNTORT(rn)->rt_nhop; 237 RIB_RUNLOCK(rh); 238 239 return (nh); 240 } 241 #endif 242 243 /* 244 * Performs reverse path forwarding lookup. 245 * If @src_if is non-zero, verifies that at least 1 path goes via 246 * this interface. 247 * If @src_if is zero, verifies that route exist. 248 * if @flags contains NHR_NOTDEFAULT, do not consider default route. 249 * 250 * Returns 1 if route matching conditions is found, 0 otherwise. 251 */ 252 int 253 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 254 uint32_t flags, const struct ifnet *src_if) 255 { 256 struct nhop_object *nh; 257 #ifdef FIB_ALGO 258 struct fib_dp *dp = &V_inet_dp[fibnum]; 259 struct flm_lookup_key key = {.addr4 = dst }; 260 261 nh = dp->f(dp->arg, key, scopeid); 262 #else 263 nh = lookup_nhop(fibnum, dst, scopeid); 264 #endif 265 if (nh != NULL) 266 return (check_urpf(nh, flags, src_if)); 267 268 return (0); 269 } 270 271 /* 272 * Function returning prefix match data along with the nexthop data. 273 * Intended to be used by the control plane code. 274 * Supported flags: 275 * NHR_UNLOCKED: do not lock radix during lookup. 276 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry 277 * and nexthop are safe to use within current epoch. Note: 278 * Note: rnd_nhop can actually be the nexthop group. 279 */ 280 struct rtentry * 281 fib4_lookup_rt(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 282 uint32_t flags, struct route_nhop_data *rnd) 283 { 284 RIB_RLOCK_TRACKER; 285 struct rib_head *rh; 286 struct radix_node *rn; 287 struct rtentry *rt; 288 289 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_rt: bad fibnum")); 290 rh = rt_tables_get_rnh(fibnum, AF_INET); 291 if (rh == NULL) 292 return (NULL); 293 294 /* Prepare lookup key */ 295 struct sockaddr_in sin4 = { 296 .sin_family = AF_INET, 297 .sin_len = sizeof(struct sockaddr_in), 298 .sin_addr = dst, 299 }; 300 301 rt = NULL; 302 if (!(flags & NHR_UNLOCKED)) 303 RIB_RLOCK(rh); 304 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 305 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 306 rt = (struct rtentry *)rn; 307 rnd->rnd_nhop = rt->rt_nhop; 308 rnd->rnd_weight = rt->rt_weight; 309 } 310 if (!(flags & NHR_UNLOCKED)) 311 RIB_RUNLOCK(rh); 312 313 return (rt); 314 } 315 316 struct nhop_object * 317 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 318 uint32_t flags) 319 { 320 struct rtentry *rt; 321 struct route_nhop_data rnd; 322 323 rt = fib4_lookup_rt(fibnum, dst, scopeid, NHR_UNLOCKED, &rnd); 324 if (rt != NULL) { 325 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0); 326 /* Ensure route & ifp is UP */ 327 if (RT_LINK_IS_UP(nh->nh_ifp)) 328 return (nh); 329 } 330 331 return (NULL); 332 } 333 334 #endif 335