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 #include "opt_inet.h" 32 #include "opt_route.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/lock.h> 37 #include <sys/rmlock.h> 38 #include <sys/malloc.h> 39 #include <sys/mbuf.h> 40 #include <sys/socket.h> 41 #include <sys/sysctl.h> 42 #include <sys/kernel.h> 43 44 #include <net/if.h> 45 #include <net/if_var.h> 46 #include <net/if_dl.h> 47 #include <net/if_private.h> 48 #include <net/route.h> 49 #include <net/route/route_ctl.h> 50 #include <net/route/route_var.h> 51 #include <net/route/fib_algo.h> 52 #include <net/route/nhop.h> 53 #include <net/toeplitz.h> 54 #include <net/vnet.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_var.h> 58 #include <netinet/in_fib.h> 59 60 #ifdef INET 61 62 /* Verify struct route compatibility */ 63 /* Assert 'struct route_in' is compatible with 'struct route' */ 64 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4); 65 66 #ifdef FIB_ALGO 67 VNET_DEFINE(struct fib_dp *, inet_dp); 68 #endif 69 70 #ifdef ROUTE_MPATH 71 struct _hash_5tuple_ipv4 { 72 struct in_addr src; 73 struct in_addr dst; 74 unsigned short src_port; 75 unsigned short dst_port; 76 char proto; 77 char spare[3]; 78 }; 79 _Static_assert(sizeof(struct _hash_5tuple_ipv4) == 16, 80 "_hash_5tuple_ipv4 size is wrong"); 81 82 uint32_t 83 fib4_calc_software_hash(struct in_addr src, struct in_addr dst, 84 unsigned short src_port, unsigned short dst_port, char proto, 85 uint32_t *phashtype) 86 { 87 struct _hash_5tuple_ipv4 data; 88 89 data.src = src; 90 data.dst = dst; 91 data.src_port = src_port; 92 data.dst_port = dst_port; 93 data.proto = proto; 94 data.spare[0] = data.spare[1] = data.spare[2] = 0; 95 96 *phashtype = M_HASHTYPE_OPAQUE; 97 98 return (toeplitz_hash(MPATH_ENTROPY_KEY_LEN, mpath_entropy_key, 99 sizeof(data), (uint8_t *)&data)); 100 } 101 #endif 102 103 /* 104 * Looks up path in fib @fibnum specified by @dst. 105 * Returns path nexthop on success. Nexthop is safe to use 106 * within the current network epoch. If longer lifetime is required, 107 * one needs to pass NHR_REF as a flag. This will return referenced 108 * nexthop. 109 */ 110 #ifdef FIB_ALGO 111 struct nhop_object * 112 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 113 uint32_t flags, uint32_t flowid) 114 { 115 struct nhop_object *nh; 116 struct fib_dp *dp = &V_inet_dp[fibnum]; 117 struct flm_lookup_key key = {.addr4 = dst }; 118 119 nh = dp->f(dp->arg, key, scopeid); 120 if (nh != NULL) { 121 nh = nhop_select(nh, flowid); 122 /* Ensure route & ifp is UP */ 123 if (RT_LINK_IS_UP(nh->nh_ifp)) { 124 if (flags & NHR_REF) 125 nhop_ref_object(nh); 126 return (nh); 127 } 128 } 129 RTSTAT_INC(rts_unreach); 130 return (NULL); 131 } 132 #else 133 struct nhop_object * 134 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 135 uint32_t flags, uint32_t flowid) 136 { 137 RIB_RLOCK_TRACKER; 138 struct rib_head *rh; 139 struct radix_node *rn; 140 struct nhop_object *nh; 141 142 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum")); 143 rh = rt_tables_get_rnh(fibnum, AF_INET); 144 if (rh == NULL) 145 return (NULL); 146 147 /* Prepare lookup key */ 148 struct sockaddr_in sin4 = { 149 .sin_family = AF_INET, 150 .sin_len = sizeof(struct sockaddr_in), 151 .sin_addr = dst, 152 }; 153 154 nh = NULL; 155 RIB_RLOCK(rh); 156 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 157 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 158 nh = nhop_select((RNTORT(rn))->rt_nhop, flowid); 159 /* Ensure route & ifp is UP */ 160 if (RT_LINK_IS_UP(nh->nh_ifp)) { 161 if (flags & NHR_REF) 162 nhop_ref_object(nh); 163 RIB_RUNLOCK(rh); 164 return (nh); 165 } 166 } 167 RIB_RUNLOCK(rh); 168 169 RTSTAT_INC(rts_unreach); 170 return (NULL); 171 } 172 #endif 173 174 inline static int 175 check_urpf_nhop(const struct nhop_object *nh, uint32_t flags, 176 const struct ifnet *src_if) 177 { 178 179 if (src_if != NULL && nh->nh_aifp == src_if) { 180 return (1); 181 } 182 if (src_if == NULL) { 183 if ((flags & NHR_NODEFAULT) == 0) 184 return (1); 185 else if ((nh->nh_flags & NHF_DEFAULT) == 0) 186 return (1); 187 } 188 189 return (0); 190 } 191 192 static int 193 check_urpf(struct nhop_object *nh, uint32_t flags, 194 const struct ifnet *src_if) 195 { 196 #ifdef ROUTE_MPATH 197 if (NH_IS_NHGRP(nh)) { 198 const struct weightened_nhop *wn; 199 uint32_t num_nhops; 200 wn = nhgrp_get_nhops((struct nhgrp_object *)nh, &num_nhops); 201 for (int i = 0; i < num_nhops; i++) { 202 if (check_urpf_nhop(wn[i].nh, flags, src_if) != 0) 203 return (1); 204 } 205 return (0); 206 } else 207 #endif 208 return (check_urpf_nhop(nh, flags, src_if)); 209 } 210 211 #ifndef FIB_ALGO 212 static struct nhop_object * 213 lookup_nhop(uint32_t fibnum, struct in_addr dst, uint32_t scopeid) 214 { 215 RIB_RLOCK_TRACKER; 216 struct rib_head *rh; 217 struct radix_node *rn; 218 struct nhop_object *nh; 219 220 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum")); 221 rh = rt_tables_get_rnh(fibnum, AF_INET); 222 if (rh == NULL) 223 return (NULL); 224 225 /* Prepare lookup key */ 226 struct sockaddr_in sin4; 227 memset(&sin4, 0, sizeof(sin4)); 228 sin4.sin_len = sizeof(struct sockaddr_in); 229 sin4.sin_addr = dst; 230 231 nh = NULL; 232 RIB_RLOCK(rh); 233 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 234 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) 235 nh = RNTORT(rn)->rt_nhop; 236 RIB_RUNLOCK(rh); 237 238 return (nh); 239 } 240 #endif 241 242 /* 243 * Performs reverse path forwarding lookup. 244 * If @src_if is non-zero, verifies that at least 1 path goes via 245 * this interface. 246 * If @src_if is zero, verifies that route exist. 247 * if @flags contains NHR_NOTDEFAULT, do not consider default route. 248 * 249 * Returns 1 if route matching conditions is found, 0 otherwise. 250 */ 251 int 252 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 253 uint32_t flags, const struct ifnet *src_if) 254 { 255 struct nhop_object *nh; 256 #ifdef FIB_ALGO 257 struct fib_dp *dp = &V_inet_dp[fibnum]; 258 struct flm_lookup_key key = {.addr4 = dst }; 259 260 nh = dp->f(dp->arg, key, scopeid); 261 #else 262 nh = lookup_nhop(fibnum, dst, scopeid); 263 #endif 264 if (nh != NULL) 265 return (check_urpf(nh, flags, src_if)); 266 267 return (0); 268 } 269 270 /* 271 * Function returning prefix match data along with the nexthop data. 272 * Intended to be used by the control plane code. 273 * Supported flags: 274 * NHR_UNLOCKED: do not lock radix during lookup. 275 * Returns pointer to rtentry and raw nexthop in @rnd. Both rtentry 276 * and nexthop are safe to use within current epoch. Note: 277 * Note: rnd_nhop can actually be the nexthop group. 278 */ 279 struct rtentry * 280 fib4_lookup_rt(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 281 uint32_t flags, struct route_nhop_data *rnd) 282 { 283 RIB_RLOCK_TRACKER; 284 struct rib_head *rh; 285 struct radix_node *rn; 286 struct rtentry *rt; 287 288 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_rt: bad fibnum")); 289 rh = rt_tables_get_rnh(fibnum, AF_INET); 290 if (rh == NULL) 291 return (NULL); 292 293 /* Prepare lookup key */ 294 struct sockaddr_in sin4 = { 295 .sin_family = AF_INET, 296 .sin_len = sizeof(struct sockaddr_in), 297 .sin_addr = dst, 298 }; 299 300 rt = NULL; 301 if (!(flags & NHR_UNLOCKED)) 302 RIB_RLOCK(rh); 303 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 304 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 305 rt = (struct rtentry *)rn; 306 rnd->rnd_nhop = rt->rt_nhop; 307 rnd->rnd_weight = rt->rt_weight; 308 } 309 if (!(flags & NHR_UNLOCKED)) 310 RIB_RUNLOCK(rh); 311 312 return (rt); 313 } 314 315 struct nhop_object * 316 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 317 uint32_t flags) 318 { 319 struct rtentry *rt; 320 struct route_nhop_data rnd; 321 322 rt = fib4_lookup_rt(fibnum, dst, scopeid, NHR_UNLOCKED, &rnd); 323 if (rt != NULL) { 324 struct nhop_object *nh = nhop_select(rnd.rnd_nhop, 0); 325 /* Ensure route & ifp is UP */ 326 if (RT_LINK_IS_UP(nh->nh_ifp)) 327 return (nh); 328 } 329 330 return (NULL); 331 } 332 333 #endif 334