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