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/if_private.h> 50 #include <net/route.h> 51 #include <net/route/route_ctl.h> 52 #include <net/route/route_var.h> 53 #include <net/route/fib_algo.h> 54 #include <net/route/nhop.h> 55 #include <net/toeplitz.h> 56 #include <net/vnet.h> 57 58 #include <netinet/in.h> 59 #include <netinet/in_var.h> 60 #include <netinet/in_fib.h> 61 62 #ifdef INET 63 64 /* Verify struct route compatibility */ 65 /* Assert 'struct route_in' is compatible with 'struct route' */ 66 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4); 67 68 #ifdef FIB_ALGO 69 VNET_DEFINE(struct fib_dp *, inet_dp); 70 #endif 71 72 #ifdef ROUTE_MPATH 73 struct _hash_5tuple_ipv4 { 74 struct in_addr src; 75 struct in_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_ipv4) == 16, 82 "_hash_5tuple_ipv4 size is wrong"); 83 84 uint32_t 85 fib4_calc_software_hash(struct in_addr src, struct in_addr dst, 86 unsigned short src_port, unsigned short dst_port, char proto, 87 uint32_t *phashtype) 88 { 89 struct _hash_5tuple_ipv4 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; 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 * Returns path nexthop on success. Nexthop is safe to use 108 * within the current network epoch. If longer lifetime is required, 109 * one needs to pass NHR_REF as a flag. This will return referenced 110 * nexthop. 111 */ 112 #ifdef FIB_ALGO 113 struct nhop_object * 114 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 115 uint32_t flags, uint32_t flowid) 116 { 117 struct nhop_object *nh; 118 struct fib_dp *dp = &V_inet_dp[fibnum]; 119 struct flm_lookup_key key = {.addr4 = dst }; 120 121 nh = dp->f(dp->arg, key, scopeid); 122 if (nh != NULL) { 123 nh = nhop_select(nh, flowid); 124 /* Ensure route & ifp is UP */ 125 if (RT_LINK_IS_UP(nh->nh_ifp)) { 126 if (flags & NHR_REF) 127 nhop_ref_object(nh); 128 return (nh); 129 } 130 } 131 RTSTAT_INC(rts_unreach); 132 return (NULL); 133 } 134 #else 135 struct nhop_object * 136 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 137 uint32_t flags, uint32_t flowid) 138 { 139 RIB_RLOCK_TRACKER; 140 struct rib_head *rh; 141 struct radix_node *rn; 142 struct nhop_object *nh; 143 144 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum")); 145 rh = rt_tables_get_rnh(fibnum, AF_INET); 146 if (rh == NULL) 147 return (NULL); 148 149 /* Prepare lookup key */ 150 struct sockaddr_in sin4 = { 151 .sin_family = AF_INET, 152 .sin_len = sizeof(struct sockaddr_in), 153 .sin_addr = dst, 154 }; 155 156 nh = NULL; 157 RIB_RLOCK(rh); 158 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 159 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 160 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid); 161 /* Ensure route & ifp is UP */ 162 if (RT_LINK_IS_UP(nh->nh_ifp)) { 163 if (flags & NHR_REF) 164 nhop_ref_object(nh); 165 RIB_RUNLOCK(rh); 166 return (nh); 167 } 168 } 169 RIB_RUNLOCK(rh); 170 171 RTSTAT_INC(rts_unreach); 172 return (NULL); 173 } 174 #endif 175 176 inline static int 177 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags, 178 const struct ifnet *src_if) 179 { 180 181 if (src_if != NULL && nh->nh_aifp == src_if) { 182 return (1); 183 } 184 if (src_if == NULL) { 185 if ((flags & NHR_NODEFAULT) == 0) 186 return (1); 187 else if ((nh->nh_flags & NHF_DEFAULT) == 0) 188 return (1); 189 } 190 191 return (0); 192 } 193 194 static int 195 check_urpf(struct nhop_object *nh, uint32_t flags, 196 const struct ifnet *src_if) 197 { 198 #ifdef ROUTE_MPATH 199 if (NH_IS_NHGRP(nh)) { 200 const struct weightened_nhop *wn; 201 uint32_t num_nhops; 202 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops); 203 for (int i = 0; i < num_nhops; i++) { 204 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0) 205 return (1); 206 } 207 return (0); 208 } else 209 #endif 210 return (check_urpf_nhop(nh, flags, src_if)); 211 } 212 213 #ifndef FIB_ALGO 214 static struct nhop_object * 215 lookup_nhop(uint32_t fibnum, struct in_addr dst, uint32_t scopeid) 216 { 217 RIB_RLOCK_TRACKER; 218 struct rib_head *rh; 219 struct radix_node *rn; 220 struct nhop_object *nh; 221 222 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum")); 223 rh = rt_tables_get_rnh(fibnum, AF_INET); 224 if (rh == NULL) 225 return (NULL); 226 227 /* Prepare lookup key */ 228 struct sockaddr_in sin4; 229 memset(&sin4, 0, sizeof(sin4)); 230 sin4.sin_len = sizeof(struct sockaddr_in); 231 sin4.sin_addr = dst; 232 233 nh = NULL; 234 RIB_RLOCK(rh); 235 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 236 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) 237 nh = RNTORT(rn)->rt_nhop; 238 RIB_RUNLOCK(rh); 239 240 return (nh); 241 } 242 #endif 243 244 /* 245 * Performs reverse path forwarding lookup. 246 * If @src_if is non-zero, verifies that at least 1 path goes via 247 * this interface. 248 * If @src_if is zero, verifies that route exist. 249 * if @flags contains NHR_NOTDEFAULT, do not consider default route. 250 * 251 * Returns 1 if route matching conditions is found, 0 otherwise. 252 */ 253 int 254 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 255 uint32_t flags, const struct ifnet *src_if) 256 { 257 struct nhop_object *nh; 258 #ifdef FIB_ALGO 259 struct fib_dp *dp = &V_inet_dp[fibnum]; 260 struct flm_lookup_key key = {.addr4 = dst }; 261 262 nh = dp->f(dp->arg, key, scopeid); 263 #else 264 nh = lookup_nhop(fibnum, dst, scopeid); 265 #endif 266 if (nh != NULL) 267 return (check_urpf(nh, flags, src_if)); 268 269 return (0); 270 } 271 272 /* 273 * Function returning prefix match data along with the nexthop data. 274 * Intended to be used by the control plane code. 275 * Supported flags: 276 * NHR_UNLOCKED: do not lock radix during lookup. 277 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry 278 * and nexthop are safe to use within current epoch. Note: 279 * Note: rnd_nhop can actually be the nexthop group. 280 */ 281 struct rtentry * 282 fib4_lookup_rt(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 283 uint32_t flags, struct route_nhop_data *rnd) 284 { 285 RIB_RLOCK_TRACKER; 286 struct rib_head *rh; 287 struct radix_node *rn; 288 struct rtentry *rt; 289 290 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_rt: bad fibnum")); 291 rh = rt_tables_get_rnh(fibnum, AF_INET); 292 if (rh == NULL) 293 return (NULL); 294 295 /* Prepare lookup key */ 296 struct sockaddr_in sin4 = { 297 .sin_family = AF_INET, 298 .sin_len = sizeof(struct sockaddr_in), 299 .sin_addr = dst, 300 }; 301 302 rt = NULL; 303 if (!(flags & NHR_UNLOCKED)) 304 RIB_RLOCK(rh); 305 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 306 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 307 rt = (struct rtentry *)rn; 308 rnd->rnd_nhop = rt->rt_nhop; 309 rnd->rnd_weight = rt->rt_weight; 310 } 311 if (!(flags & NHR_UNLOCKED)) 312 RIB_RUNLOCK(rh); 313 314 return (rt); 315 } 316 317 struct nhop_object * 318 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 319 uint32_t flags) 320 { 321 struct rtentry *rt; 322 struct route_nhop_data rnd; 323 324 rt = fib4_lookup_rt(fibnum, dst, scopeid, NHR_UNLOCKED, &rnd); 325 if (rt != NULL) { 326 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0); 327 /* Ensure route & ifp is UP */ 328 if (RT_LINK_IS_UP(nh->nh_ifp)) 329 return (nh); 330 } 331 332 return (NULL); 333 } 334 335 #endif 336