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