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
rib4_set_nh_pfxflags(u_int fibnum,const struct sockaddr * addr,const struct sockaddr * mask,struct nhop_object * nh)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_ifnet_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
rib4_augment_nh(u_int fibnum,struct nhop_object * nh)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 *
in_inithead(uint32_t fibnum)117 in_inithead(uint32_t fibnum)
118 {
119 struct rib_head *rh;
120
121 rh = rt_table_init(32, AF_INET, fibnum);
122 rh->rnh_set_nh_pfxflags = rib4_set_nh_pfxflags;
123 rh->rnh_augment_nh = rib4_augment_nh;
124
125 return (rh);
126 }
127
128 #ifdef VIMAGE
129 void
in_detachhead(struct rib_head * rh)130 in_detachhead(struct rib_head *rh)
131 {
132
133 rt_table_destroy(rh);
134 }
135 #endif
136
137 /*
138 * This zaps old routes when the interface goes down or interface
139 * address is deleted. In the latter case, it deletes static routes
140 * that point to this address. If we don't do this, we may end up
141 * using the old address in the future. The ones we always want to
142 * get rid of are things like ARP entries, since the user might down
143 * the interface, walk over to a completely different network, and
144 * plug back in.
145 */
146 struct in_ifadown_arg {
147 struct ifaddr *ifa;
148 int del;
149 };
150
151 static int
in_ifadownkill(const struct rtentry * rt,const struct nhop_object * nh,void * xap)152 in_ifadownkill(const struct rtentry *rt, const struct nhop_object *nh,
153 void *xap)
154 {
155 struct in_ifadown_arg *ap = xap;
156
157 if (nh->nh_ifa != ap->ifa)
158 return (0);
159
160 if ((nhop_get_rtflags(nh) & RTF_STATIC) != 0 && ap->del == 0)
161 return (0);
162
163 return (1);
164 }
165
166 void
in_ifadown(struct ifaddr * ifa,int delete)167 in_ifadown(struct ifaddr *ifa, int delete)
168 {
169 struct in_ifadown_arg arg;
170
171 KASSERT(ifa->ifa_addr->sa_family == AF_INET,
172 ("%s: wrong family", __func__));
173
174 arg.ifa = ifa;
175 arg.del = delete;
176
177 rib_foreach_table_walk_del(AF_INET, in_ifadownkill, &arg);
178 ifa->ifa_flags &= ~IFA_ROUTE; /* XXXlocking? */
179 }
180