1 /*- 2 * Copyright 1994, 1995 Massachusetts Institute of Technology 3 * 4 * Permission to use, copy, modify, and distribute this software and 5 * its documentation for any purpose and without fee is hereby 6 * granted, provided that both the above copyright notice and this 7 * permission notice appear in all copies, that both the above 8 * copyright notice and this permission notice appear in all 9 * supporting documentation, and that the name of M.I.T. not be used 10 * in advertising or publicity pertaining to distribution of the 11 * software without specific, written prior permission. M.I.T. makes 12 * no representations about the suitability of this software for any 13 * purpose. It is provided "as is" without express or implied 14 * warranty. 15 * 16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS 17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, 18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT 20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/kernel.h> 33 #include <sys/sysctl.h> 34 #include <sys/socket.h> 35 #include <sys/mbuf.h> 36 37 #include <net/if.h> 38 #include <net/if_var.h> 39 #include <net/if_private.h> 40 #include <net/route.h> 41 #include <net/route/route_ctl.h> 42 #include <net/route/route_var.h> 43 #include <net/route/nhop.h> 44 #include <net/vnet.h> 45 46 #include <netinet/in.h> 47 #include <netinet/in_var.h> 48 #include <netinet/ip.h> 49 #include <netinet/ip_icmp.h> 50 #include <netinet/ip_var.h> 51 52 static int 53 rib4_set_nh_pfxflags(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask, 54 struct nhop_object *nh) 55 { 56 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr; 57 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask; 58 bool is_broadcast = false; 59 60 if (mask == NULL) { 61 nhop_set_pxtype_flag(nh, NHF_HOST); 62 /* 63 * Backward compatibility: 64 * if the destination is broadcast, 65 * mark route as broadcast. 66 * This behavior was useful when route cloning 67 * was in place, so there was an explicit cloned 68 * route for every broadcasted address. 69 * Currently (2020-04) there is no kernel machinery 70 * to do route cloning, though someone might explicitly 71 * add these routes to support some cases with active-active 72 * load balancing. Given that, retain this support. 73 */ 74 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) 75 is_broadcast = true; 76 } else if (mask4->sin_addr.s_addr == 0) 77 nhop_set_pxtype_flag(nh, NHF_DEFAULT); 78 else 79 nhop_set_pxtype_flag(nh, 0); 80 81 nhop_set_broadcast(nh, is_broadcast); 82 83 return (0); 84 } 85 86 static int 87 rib4_augment_nh(u_int fibnum, struct nhop_object *nh) 88 { 89 /* 90 * Check route MTU: 91 * inherit interface MTU if not set or 92 * check if MTU is too large. 93 */ 94 if (nh->nh_mtu == 0) { 95 nh->nh_mtu = nh->nh_ifp->if_mtu; 96 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu) 97 nh->nh_mtu = nh->nh_ifp->if_mtu; 98 99 /* Set nhop type to basic per-AF nhop */ 100 if (nhop_get_type(nh) == 0) { 101 uint16_t nh_type; 102 if (nh->nh_flags & NHF_GATEWAY) 103 nh_type = NH_TYPE_IPV4_ETHER_NHOP; 104 else 105 nh_type = NH_TYPE_IPV4_ETHER_RSLV; 106 107 nhop_set_type(nh, nh_type); 108 } 109 110 return (0); 111 } 112 113 /* 114 * Initialize our routing tree. 115 */ 116 struct rib_head * 117 in_inithead(uint32_t fibnum) 118 { 119 struct rib_head *rh; 120 121 rh = rt_table_init(32, AF_INET, fibnum); 122 if (rh == NULL) 123 return (NULL); 124 125 rh->rnh_set_nh_pfxflags = rib4_set_nh_pfxflags; 126 rh->rnh_augment_nh = rib4_augment_nh; 127 128 return (rh); 129 } 130 131 #ifdef VIMAGE 132 void 133 in_detachhead(struct rib_head *rh) 134 { 135 136 rt_table_destroy(rh); 137 } 138 #endif 139 140 /* 141 * This zaps old routes when the interface goes down or interface 142 * address is deleted. In the latter case, it deletes static routes 143 * that point to this address. If we don't do this, we may end up 144 * using the old address in the future. The ones we always want to 145 * get rid of are things like ARP entries, since the user might down 146 * the interface, walk over to a completely different network, and 147 * plug back in. 148 */ 149 struct in_ifadown_arg { 150 struct ifaddr *ifa; 151 int del; 152 }; 153 154 static int 155 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh, 156 void *xap) 157 { 158 struct in_ifadown_arg *ap = xap; 159 160 if (nh->nh_ifa != ap->ifa) 161 return (0); 162 163 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0) 164 return (0); 165 166 return (1); 167 } 168 169 void 170 in_ifadown(struct ifaddr *ifa, int delete) 171 { 172 struct in_ifadown_arg arg; 173 174 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 175 ("%s: wrong family", __func__)); 176 177 arg.ifa = ifa; 178 arg.del = delete; 179 180 rib_foreach_table_walk_del(AF_INET, in_ifadownkill, &arg); 181 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 182 } 183