xref: /freebsd/sys/net/route/route_ifaddrs.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1986, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)route.c	8.3.1.1 (Berkeley) 2/23/95
32  * $FreeBSD$
33  */
34 
35 #include "opt_route.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42 #include <sys/syslog.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/rmlock.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/if_dl.h>
50 #include <net/route.h>
51 #include <net/route/route_ctl.h>
52 #include <net/route/route_var.h>
53 #include <net/route/nhop.h>
54 #include <net/vnet.h>
55 
56 #include <netinet/in.h>
57 
58 /*
59  * Control interface address fib propagation.
60  * By default, interface address routes are added to the fib of the interface.
61  * Once set to non-zero, adds interface address route to all fibs.
62  */
63 VNET_DEFINE(u_int, rt_add_addr_allfibs) = 0;
64 SYSCTL_UINT(_net, OID_AUTO, add_addr_allfibs, CTLFLAG_RWTUN | CTLFLAG_VNET,
65     &VNET_NAME(rt_add_addr_allfibs), 0, "");
66 
67 /*
68  * Executes routing tables change specified by @cmd and @info for the fib
69  * @fibnum. Generates routing message on success.
70  * Note: it assumes there is only single route (interface route) for the
71  * provided prefix.
72  * Returns 0 on success or errno.
73  */
74 static int
75 rib_handle_ifaddr_one(uint32_t fibnum, int cmd, struct rt_addrinfo *info)
76 {
77 	struct rib_cmd_info rc;
78 	struct nhop_object *nh;
79 	int error;
80 
81 	error = rib_action(fibnum, cmd, info, &rc);
82 	if (error == 0) {
83 		if (cmd == RTM_ADD)
84 			nh = nhop_select(rc.rc_nh_new, 0);
85 		else
86 			nh = nhop_select(rc.rc_nh_old, 0);
87 		rt_routemsg(cmd, rc.rc_rt, nh, fibnum);
88 	}
89 
90 	return (error);
91 }
92 
93 /*
94  * Adds/deletes interface prefix specified by @info to the routing table.
95  * If V_rt_add_addr_allfibs is set, iterates over all existing routing
96  * tables, otherwise uses fib in @fibnum. Generates routing message for
97  *  each table.
98  * Returns 0 on success or errno.
99  */
100 int
101 rib_handle_ifaddr_info(uint32_t fibnum, int cmd, struct rt_addrinfo *info)
102 {
103 	int error, last_error = 0;
104 	bool didwork = false;
105 
106 	if (V_rt_add_addr_allfibs == 0) {
107 		error = rib_handle_ifaddr_one(fibnum, cmd, info);
108 		didwork = (error == 0);
109 	} else {
110 		for (fibnum = 0; fibnum < V_rt_numfibs; fibnum++) {
111 			error = rib_handle_ifaddr_one(fibnum, cmd, info);
112 			if (error == 0)
113 				didwork = true;
114 			else
115 				last_error = error;
116 		}
117 	}
118 
119 	if (cmd == RTM_DELETE) {
120 		if (didwork) {
121 			error = 0;
122 		} else {
123 			/* we only give an error if it wasn't in any table */
124 			error = ((info->rti_flags & RTF_HOST) ?
125 			    EHOSTUNREACH : ENETUNREACH);
126 		}
127 	} else {
128 		if (last_error != 0) {
129 			/* return an error if any of them failed */
130 			error = last_error;
131 		}
132 	}
133 	return (error);
134 }
135 
136 static int
137 ifa_maintain_loopback_route(int cmd, const char *otype, struct ifaddr *ifa,
138     struct sockaddr *ia)
139 {
140 	struct rib_cmd_info rc;
141 	struct epoch_tracker et;
142 	int error;
143 	struct rt_addrinfo info;
144 	struct sockaddr_dl null_sdl;
145 	struct ifnet *ifp;
146 	struct ifaddr *rti_ifa = NULL;
147 
148 	ifp = ifa->ifa_ifp;
149 
150 	NET_EPOCH_ENTER(et);
151 	bzero(&info, sizeof(info));
152 	if (cmd != RTM_DELETE)
153 		info.rti_ifp = V_loif;
154 	if (cmd == RTM_ADD) {
155 		/* explicitly specify (loopback) ifa */
156 		if (info.rti_ifp != NULL) {
157 			rti_ifa = ifaof_ifpforaddr(ifa->ifa_addr, info.rti_ifp);
158 			if (rti_ifa != NULL)
159 				ifa_ref(rti_ifa);
160 			info.rti_ifa = rti_ifa;
161 		}
162 	}
163 	info.rti_flags = ifa->ifa_flags | RTF_HOST | RTF_STATIC | RTF_PINNED;
164 	info.rti_info[RTAX_DST] = ia;
165 	info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&null_sdl;
166 	link_init_sdl(ifp, (struct sockaddr *)&null_sdl, ifp->if_type);
167 
168 	error = rib_action(ifp->if_fib, cmd, &info, &rc);
169 	NET_EPOCH_EXIT(et);
170 
171 	if (rti_ifa != NULL)
172 		ifa_free(rti_ifa);
173 
174 	if (error == 0 ||
175 	    (cmd == RTM_ADD && error == EEXIST) ||
176 	    (cmd == RTM_DELETE && (error == ENOENT || error == ESRCH)))
177 		return (error);
178 
179 	log(LOG_DEBUG, "%s: %s failed for interface %s: %u\n",
180 		__func__, otype, if_name(ifp), error);
181 
182 	return (error);
183 }
184 
185 int
186 ifa_add_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
187 {
188 
189 	return (ifa_maintain_loopback_route(RTM_ADD, "insertion", ifa, ia));
190 }
191 
192 int
193 ifa_del_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
194 {
195 
196 	return (ifa_maintain_loopback_route(RTM_DELETE, "deletion", ifa, ia));
197 }
198 
199 int
200 ifa_switch_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
201 {
202 
203 	return (ifa_maintain_loopback_route(RTM_CHANGE, "switch", ifa, ia));
204 }
205 
206 
207