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 extern int in_inithead(void **head, int off, u_int fibnum); 58 #ifdef VIMAGE 59 extern int in_detachhead(void **head, int off); 60 #endif 61 62 static int 63 rib4_preadd(u_int fibnum, const struct sockaddr *addr, const struct sockaddr *mask, 64 struct nhop_object *nh) 65 { 66 const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr; 67 uint16_t nh_type; 68 int rt_flags; 69 70 /* XXX: RTF_LOCAL && RTF_MULTICAST */ 71 72 rt_flags = nhop_get_rtflags(nh); 73 74 if (rt_flags & RTF_HOST) { 75 76 /* 77 * Backward compatibility: 78 * if the destination is broadcast, 79 * mark route as broadcast. 80 * This behavior was useful when route cloning 81 * was in place, so there was an explicit cloned 82 * route for every broadcasted address. 83 * Currently (2020-04) there is no kernel machinery 84 * to do route cloning, though someone might explicitly 85 * add these routes to support some cases with active-active 86 * load balancing. Given that, retain this support. 87 */ 88 if (in_broadcast(addr4->sin_addr, nh->nh_ifp)) { 89 rt_flags |= RTF_BROADCAST; 90 nhop_set_rtflags(nh, rt_flags); 91 nh->nh_flags |= NHF_BROADCAST; 92 } 93 } 94 95 /* 96 * Check route MTU: 97 * inherit interface MTU if not set or 98 * check if MTU is too large. 99 */ 100 if (nh->nh_mtu == 0) { 101 nh->nh_mtu = nh->nh_ifp->if_mtu; 102 } else if (nh->nh_mtu > nh->nh_ifp->if_mtu) 103 nh->nh_mtu = nh->nh_ifp->if_mtu; 104 105 /* Ensure that default route nhop has special flag */ 106 const struct sockaddr_in *mask4 = (const struct sockaddr_in *)mask; 107 if ((rt_flags & RTF_HOST) == 0 && mask4 != NULL && 108 mask4->sin_addr.s_addr == 0) 109 nh->nh_flags |= NHF_DEFAULT; 110 111 /* Set nhop type to basic per-AF nhop */ 112 if (nhop_get_type(nh) == 0) { 113 if (nh->nh_flags & NHF_GATEWAY) 114 nh_type = NH_TYPE_IPV4_ETHER_NHOP; 115 else 116 nh_type = NH_TYPE_IPV4_ETHER_RSLV; 117 118 nhop_set_type(nh, nh_type); 119 } 120 121 return (0); 122 } 123 124 static int _in_rt_was_here; 125 /* 126 * Initialize our routing tree. 127 */ 128 int 129 in_inithead(void **head, int off, u_int fibnum) 130 { 131 struct rib_head *rh; 132 133 rh = rt_table_init(32, AF_INET, fibnum); 134 if (rh == NULL) 135 return (0); 136 137 rh->rnh_preadd = rib4_preadd; 138 #ifdef RADIX_MPATH 139 rt_mpath_init_rnh(rh); 140 #endif 141 *head = (void *)rh; 142 143 if (_in_rt_was_here == 0 ) { 144 _in_rt_was_here = 1; 145 } 146 return 1; 147 } 148 149 #ifdef VIMAGE 150 int 151 in_detachhead(void **head, int off) 152 { 153 154 rt_table_destroy((struct rib_head *)(*head)); 155 return (1); 156 } 157 #endif 158 159 /* 160 * This zaps old routes when the interface goes down or interface 161 * address is deleted. In the latter case, it deletes static routes 162 * that point to this address. If we don't do this, we may end up 163 * using the old address in the future. The ones we always want to 164 * get rid of are things like ARP entries, since the user might down 165 * the interface, walk over to a completely different network, and 166 * plug back in. 167 */ 168 struct in_ifadown_arg { 169 struct ifaddr *ifa; 170 int del; 171 }; 172 173 static int 174 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh, 175 void *xap) 176 { 177 struct in_ifadown_arg *ap = xap; 178 179 if (nh->nh_ifa != ap->ifa) 180 return (0); 181 182 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0) 183 return (0); 184 185 return (1); 186 } 187 188 void 189 in_ifadown(struct ifaddr *ifa, int delete) 190 { 191 struct in_ifadown_arg arg; 192 193 KASSERT(ifa->ifa_addr->sa_family == AF_INET, 194 ("%s: wrong family", __func__)); 195 196 arg.ifa = ifa; 197 arg.del = delete; 198 199 rt_foreach_fib_walk_del(AF_INET, in_ifadownkill, &arg); 200 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */ 201 } 202 203