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 #include "opt_mpath.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_var.h> 52 #include <net/route/nhop.h> 53 #include <net/vnet.h> 54 55 #ifdef RADIX_MPATH 56 #include <net/radix_mpath.h> 57 #endif 58 59 #include <netinet/in.h> 60 #include <netinet/in_var.h> 61 #include <netinet/in_fib.h> 62 63 #ifdef INET 64 65 /* Verify struct route compatiblity */ 66 /* Assert 'struct route_in' is compatible with 'struct route' */ 67 CHK_STRUCT_ROUTE_COMPAT(struct route_in, ro_dst4); 68 69 /* 70 * Looks up path in fib @fibnum specified by @dst. 71 * Returns path nexthop on success. Nexthop is safe to use 72 * within the current network epoch. If longer lifetime is required, 73 * one needs to pass NHR_REF as a flag. This will return referenced 74 * nexthop. 75 */ 76 struct nhop_object * 77 fib4_lookup(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 78 uint32_t flags, uint32_t flowid) 79 { 80 RIB_RLOCK_TRACKER; 81 struct rib_head *rh; 82 struct radix_node *rn; 83 struct rtentry *rt; 84 struct nhop_object *nh; 85 86 KASSERT((fibnum < rt_numfibs), ("fib4_lookup: bad fibnum")); 87 rh = rt_tables_get_rnh(fibnum, AF_INET); 88 if (rh == NULL) 89 return (NULL); 90 91 /* Prepare lookup key */ 92 struct sockaddr_in sin4; 93 memset(&sin4, 0, sizeof(sin4)); 94 sin4.sin_family = AF_INET; 95 sin4.sin_len = sizeof(struct sockaddr_in); 96 sin4.sin_addr = dst; 97 98 nh = NULL; 99 RIB_RLOCK(rh); 100 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 101 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 102 rt = RNTORT(rn); 103 #ifdef RADIX_MPATH 104 if (rt_mpath_next(rt) != NULL) 105 rt = rt_mpath_selectrte(rt, flowid); 106 #endif 107 nh = rt->rt_nhop; 108 /* Ensure route & ifp is UP */ 109 if (RT_LINK_IS_UP(nh->nh_ifp)) { 110 if (flags & NHR_REF) 111 nhop_ref_object(nh); 112 RIB_RUNLOCK(rh); 113 return (nh); 114 } 115 } 116 RIB_RUNLOCK(rh); 117 118 RTSTAT_INC(rts_unreach); 119 return (NULL); 120 } 121 122 inline static int 123 check_urpf(const struct nhop_object *nh, uint32_t flags, 124 const struct ifnet *src_if) 125 { 126 127 if (src_if != NULL && nh->nh_aifp == src_if) { 128 return (1); 129 } 130 if (src_if == NULL) { 131 if ((flags & NHR_NODEFAULT) == 0) 132 return (1); 133 else if ((nh->nh_flags & NHF_DEFAULT) == 0) 134 return (1); 135 } 136 137 return (0); 138 } 139 140 #ifdef RADIX_MPATH 141 inline static int 142 check_urpf_mpath(struct rtentry *rt, uint32_t flags, 143 const struct ifnet *src_if) 144 { 145 146 while (rt != NULL) { 147 if (check_urpf(rt->rt_nhop, flags, src_if) != 0) 148 return (1); 149 rt = rt_mpath_next(rt); 150 } 151 152 return (0); 153 } 154 #endif 155 156 /* 157 * Performs reverse path forwarding lookup. 158 * If @src_if is non-zero, verifies that at least 1 path goes via 159 * this interface. 160 * If @src_if is zero, verifies that route exist. 161 * if @flags contains NHR_NOTDEFAULT, do not consider default route. 162 * 163 * Returns 1 if route matching conditions is found, 0 otherwise. 164 */ 165 int 166 fib4_check_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 167 uint32_t flags, const struct ifnet *src_if) 168 { 169 RIB_RLOCK_TRACKER; 170 struct rib_head *rh; 171 struct radix_node *rn; 172 struct rtentry *rt; 173 int ret; 174 175 KASSERT((fibnum < rt_numfibs), ("fib4_check_urpf: bad fibnum")); 176 rh = rt_tables_get_rnh(fibnum, AF_INET); 177 if (rh == NULL) 178 return (0); 179 180 /* Prepare lookup key */ 181 struct sockaddr_in sin4; 182 memset(&sin4, 0, sizeof(sin4)); 183 sin4.sin_len = sizeof(struct sockaddr_in); 184 sin4.sin_addr = dst; 185 186 RIB_RLOCK(rh); 187 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 188 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 189 rt = RNTORT(rn); 190 #ifdef RADIX_MPATH 191 ret = check_urpf_mpath(rt, flags, src_if); 192 #else 193 ret = check_urpf(rt->rt_nhop, flags, src_if); 194 #endif 195 RIB_RUNLOCK(rh); 196 return (ret); 197 } 198 RIB_RUNLOCK(rh); 199 200 return (0); 201 } 202 203 struct nhop_object * 204 fib4_lookup_debugnet(uint32_t fibnum, struct in_addr dst, uint32_t scopeid, 205 uint32_t flags) 206 { 207 struct rib_head *rh; 208 struct radix_node *rn; 209 struct rtentry *rt; 210 struct nhop_object *nh; 211 212 KASSERT((fibnum < rt_numfibs), ("fib4_lookup_debugnet: bad fibnum")); 213 rh = rt_tables_get_rnh(fibnum, AF_INET); 214 if (rh == NULL) 215 return (NULL); 216 217 /* Prepare lookup key */ 218 struct sockaddr_in sin4; 219 memset(&sin4, 0, sizeof(sin4)); 220 sin4.sin_family = AF_INET; 221 sin4.sin_len = sizeof(struct sockaddr_in); 222 sin4.sin_addr = dst; 223 224 nh = NULL; 225 /* unlocked lookup */ 226 rn = rh->rnh_matchaddr((void *)&sin4, &rh->head); 227 if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0)) { 228 rt = RNTORT(rn); 229 #ifdef RADIX_MPATH 230 if (rt_mpath_next(rt) != NULL) 231 rt = rt_mpath_selectrte(rt, 0); 232 #endif 233 nh = rt->rt_nhop; 234 /* Ensure route & ifp is UP */ 235 if (RT_LINK_IS_UP(nh->nh_ifp)) { 236 if (flags & NHR_REF) 237 nhop_ref_object(nh); 238 return (nh); 239 } 240 } 241 242 return (NULL); 243 } 244 245 #endif 246