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_var.h> 46 #include <net/route/nhop.h> 47 #include <net/route/shared.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 extern int in_inithead(void **head, int off, u_int fibnum); 57 #ifdef VIMAGE 58 extern int in_detachhead(void **head, int off); 59 #endif 60 61 static int 62 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask, 63 struct nhop_object *nh) 64 { 65 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr; 66 uint16_t nh_type; 67 int rt_flags; 68 69 /* XXX: RTF_LOCAL && RTF_MULTICAST */ 70 71 rt_flags = nhop_get_rtflags(nh); 72 73 if (rt_flags & RTF_HOST) { 74 75 /* 76 * Backward compatibility: 77 * if the destination is broadcast, 78 * mark route as broadcast. 79 * This behavior was useful when route cloning 80 * was in place, so there was an explicit cloned 81 * route for every broadcasted address. 82 * Currently (2020-04) there is no kernel machinery 83 * to do route cloning, though someone might explicitly 84 * add these routes to support some cases with active-active 85 * load balancing. Given that, retain this support. 86 */ 87 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) { 88 rt_flags |= RTF_BROADCAST; 89 nhop_set_rtflags(nh, rt_flags); 90 nh->nh_flags |= NHF_BROADCAST; 91 } 92 } 93 94 /* 95 * Check route MTU: 96 * inherit interface MTU if not set or 97 * check if MTU is too large. 98 */ 99 if (nh->nh_mtu == 0) { 100 nh->nh_mtu = nh->nh_ifp->if_mtu; 101 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu) 102 nh->nh_mtu = nh->nh_ifp->if_mtu; 103 104 /* Ensure that default route nhop has special flag */ 105 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask; 106 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL && 107 mask4->sin_addr.s_addr == 0) 108 nh->nh_flags |= NHF_DEFAULT; 109 110 /* Set nhop type to basic per-AF nhop */ 111 if (nhop_get_type(nh) == 0) { 112 if (nh->nh_flags & NHF_GATEWAY) 113 nh_type = NH_TYPE_IPV4_ETHER_NHOP; 114 else 115 nh_type = NH_TYPE_IPV4_ETHER_RSLV; 116 117 nhop_set_type(nh, nh_type); 118 } 119 120 return (0); 121 } 122 123 static int _in_rt_was_here; 124 /* 125 * Initialize our routing tree. 126 */ 127 int 128 in_inithead(void **head, int off, u_int fibnum) 129 { 130 struct rib_head *rh; 131 132 rh = rt_table_init(32, AF_INET, fibnum); 133 if (rh == NULL) 134 return (0); 135 136 rh->rnh_preadd = rib4_preadd; 137 #ifdef RADIX_MPATH 138 rt_mpath_init_rnh(rh); 139 #endif 140 *head = (void *)rh; 141 142 if (_in_rt_was_here == 0 ) { 143 _in_rt_was_here = 1; 144 } 145 return 1; 146 } 147 148 #ifdef VIMAGE 149 int 150 in_detachhead(void **head, int off) 151 { 152 153 rt_table_destroy((struct rib_head *)(*head)); 154 return (1); 155 } 156 #endif 157 158 /* 159 * This zaps old routes when the interface goes down or interface 160 * address is deleted. In the latter case, it deletes static routes 161 * that point to this address. If we don't do this, we may end up 162 * using the old address in the future. The ones we always want to 163 * get rid of are things like ARP entries, since the user might down 164 * the interface, walk over to a completely different network, and 165 * plug back in. 166 */ 167 struct in_ifadown_arg { 168 struct ifaddr *ifa; 169 int del; 170 }; 171 172 static int 173 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh, 174 void *xap) 175 { 176 struct in_ifadown_arg *ap = xap; 177 178 if (nh->nh_ifa != ap->ifa) 179 return (0); 180 181 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0) 182 return (0); 183 184 return (1); 185 } 186 187 void 188 in_ifadown(struct ifaddr *ifa, int delete) 189 { 190 struct in_ifadown_arg arg; 191 192 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 193 ("%s: wrong family", __func__)); 194 195 arg.ifa = ifa; 196 arg.del = delete; 197 198 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg); 199 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 200 } 201 202