xref: /freebsd/sys/net/route/route_ifaddrs.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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  */
33 
34 #include "opt_route.h"
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/malloc.h>
39 #include <sys/socket.h>
40 #include <sys/sysctl.h>
41 #include <sys/syslog.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/rmlock.h>
45 
46 #include <net/if.h>
47 #include <net/if_var.h>
48 #include <net/if_private.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 = 0, 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 
147 	ifp = ifa->ifa_ifp;
148 
149 	NET_EPOCH_ENTER(et);
150 	bzero(&info, sizeof(info));
151 	if (cmd != RTM_DELETE)
152 		info.rti_ifp = V_loif;
153 	if (cmd == RTM_ADD) {
154 		/* explicitly specify (loopback) ifa */
155 		if (info.rti_ifp != NULL)
156 			info.rti_ifa = ifaof_ifpforaddr(ifa->ifa_addr, info.rti_ifp);
157 	}
158 	info.rti_flags = ifa->ifa_flags | RTF_HOST | RTF_STATIC | RTF_PINNED;
159 	info.rti_info[RTAX_DST] = ia;
160 	info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&null_sdl;
161 	link_init_sdl(ifp, (struct sockaddr *)&null_sdl, ifp->if_type);
162 
163 	error = rib_action(ifp->if_fib, cmd, &info, &rc);
164 	NET_EPOCH_EXIT(et);
165 
166 	if (error == 0 ||
167 	    (cmd == RTM_ADD && error == EEXIST) ||
168 	    (cmd == RTM_DELETE && (error == ENOENT || error == ESRCH)))
169 		return (error);
170 
171 	log(LOG_DEBUG, "%s: %s failed for interface %s: %u\n",
172 		__func__, otype, if_name(ifp), error);
173 
174 	return (error);
175 }
176 
177 int
178 ifa_add_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
179 {
180 
181 	return (ifa_maintain_loopback_route(RTM_ADD, "insertion", ifa, ia));
182 }
183 
184 int
185 ifa_del_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
186 {
187 
188 	return (ifa_maintain_loopback_route(RTM_DELETE, "deletion", ifa, ia));
189 }
190 
191 int
192 ifa_switch_loopback_route(struct ifaddr *ifa, struct sockaddr *ia)
193 {
194 
195 	return (ifa_maintain_loopback_route(RTM_CHANGE, "switch", ifa, ia));
196 }
197 
198 static bool
199 match_kernel_route(const struct rtentry *rt, struct nhop_object *nh)
200 {
201 	if (!NH_IS_NHGRP(nh) && (nhop_get_rtflags(nh) & RTF_PINNED) &&
202 	    nh->nh_aifp->if_fib == nhop_get_fibnum(nh))
203 		return (true);
204 	return (false);
205 }
206 
207 static int
208 pick_kernel_route(struct rtentry *rt, void *arg)
209 {
210 	struct nhop_object *nh = rt->rt_nhop;
211 	struct rib_head *rh_dst = (struct rib_head *)arg;
212 
213 	if (match_kernel_route(rt, nh)) {
214 		struct rib_cmd_info rc = {};
215 		struct route_nhop_data rnd = {
216 			.rnd_nhop = nh,
217 			.rnd_weight = rt->rt_weight,
218 		};
219 		rib_copy_route(rt, &rnd, rh_dst, &rc);
220 	}
221 	return (0);
222 }
223 
224 /*
225  * Tries to copy kernel routes matching pattern from @rh_src to @rh_dst.
226  *
227  * Note: as this function acquires locks for both @rh_src and @rh_dst,
228  *  it needs to be called under RTABLES_LOCK() to avoid deadlocking
229  * with multiple ribs.
230  */
231 void
232 rib_copy_kernel_routes(struct rib_head *rh_src, struct rib_head *rh_dst)
233 {
234 	struct epoch_tracker et;
235 
236 	if (V_rt_add_addr_allfibs == 0)
237 		return;
238 
239 	NET_EPOCH_ENTER(et);
240 	rib_walk_ext_internal(rh_src, false, pick_kernel_route, NULL, rh_dst);
241 	NET_EPOCH_EXIT(et);
242 }
243 
244