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