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/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "opt_mpath.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/kernel.h> 38 #include <sys/sysctl.h> 39 #include <sys/socket.h> 40 #include <sys/mbuf.h> 41 42 #include <net/if.h> 43 #include <net/if_var.h> 44 #include <net/route.h> 45 #include <net/route/route_ctl.h> 46 #include <net/route/route_var.h> 47 #include <net/route/nhop.h> 48 #include <net/route/shared.h> 49 #include <net/vnet.h> 50 51 #include <netinet/in.h> 52 #include <netinet/in_var.h> 53 #include <netinet/ip.h> 54 #include <netinet/ip_icmp.h> 55 #include <netinet/ip_var.h> 56 57 58 static int 59 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask, 60 struct nhop_object *nh) 61 { 62 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr; 63 uint16_t nh_type; 64 int rt_flags; 65 66 /* XXX: RTF_LOCAL && RTF_MULTICAST */ 67 68 rt_flags = nhop_get_rtflags(nh); 69 70 if (rt_flags & RTF_HOST) { 71 72 /* 73 * Backward compatibility: 74 * if the destination is broadcast, 75 * mark route as broadcast. 76 * This behavior was useful when route cloning 77 * was in place, so there was an explicit cloned 78 * route for every broadcasted address. 79 * Currently (2020-04) there is no kernel machinery 80 * to do route cloning, though someone might explicitly 81 * add these routes to support some cases with active-active 82 * load balancing. Given that, retain this support. 83 */ 84 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) { 85 rt_flags |= RTF_BROADCAST; 86 nhop_set_rtflags(nh, rt_flags); 87 nh->nh_flags |= NHF_BROADCAST; 88 } 89 } 90 91 /* 92 * Check route MTU: 93 * inherit interface MTU if not set or 94 * check if MTU is too large. 95 */ 96 if (nh->nh_mtu == 0) { 97 nh->nh_mtu = nh->nh_ifp->if_mtu; 98 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu) 99 nh->nh_mtu = nh->nh_ifp->if_mtu; 100 101 /* Ensure that default route nhop has special flag */ 102 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask; 103 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL && 104 mask4->sin_addr.s_addr == 0) 105 nh->nh_flags |= NHF_DEFAULT; 106 107 /* Set nhop type to basic per-AF nhop */ 108 if (nhop_get_type(nh) == 0) { 109 if (nh->nh_flags & NHF_GATEWAY) 110 nh_type = NH_TYPE_IPV4_ETHER_NHOP; 111 else 112 nh_type = NH_TYPE_IPV4_ETHER_RSLV; 113 114 nhop_set_type(nh, nh_type); 115 } 116 117 return (0); 118 } 119 120 /* 121 * Initialize our routing tree. 122 */ 123 struct rib_head * 124 in_inithead(uint32_t fibnum) 125 { 126 struct rib_head *rh; 127 128 rh = rt_table_init(32, AF_INET, fibnum); 129 if (rh == NULL) 130 return (NULL); 131 132 rh->rnh_preadd = rib4_preadd; 133 #ifdef RADIX_MPATH 134 rt_mpath_init_rnh(rh); 135 #endif 136 137 return (rh); 138 } 139 140 #ifdef VIMAGE 141 void 142 in_detachhead(struct rib_head *rh) 143 { 144 145 rt_table_destroy(rh); 146 } 147 #endif 148 149 /* 150 * This zaps old routes when the interface goes down or interface 151 * address is deleted. In the latter case, it deletes static routes 152 * that point to this address. If we don't do this, we may end up 153 * using the old address in the future. The ones we always want to 154 * get rid of are things like ARP entries, since the user might down 155 * the interface, walk over to a completely different network, and 156 * plug back in. 157 */ 158 struct in_ifadown_arg { 159 struct ifaddr *ifa; 160 int del; 161 }; 162 163 static int 164 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh, 165 void *xap) 166 { 167 struct in_ifadown_arg *ap = xap; 168 169 if (nh->nh_ifa != ap->ifa) 170 return (0); 171 172 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0) 173 return (0); 174 175 return (1); 176 } 177 178 void 179 in_ifadown(struct ifaddr *ifa, int delete) 180 { 181 struct in_ifadown_arg arg; 182 183 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 184 ("%s: wrong family", __func__)); 185 186 arg.ifa = ifa; 187 arg.del = delete; 188 189 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg); 190 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 191 } 192 193