xref: /aosp_15_r20/external/libnl/lib/route/route.c (revision 4dc78e53d49367fa8e61b07018507c90983a077d)
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2003-2008 Thomas Graf <[email protected]>
4  */
5 
6 /**
7  * @ingroup rtnl
8  * @defgroup route Routing
9  * @brief
10  * @{
11  */
12 
13 #include "nl-default.h"
14 
15 #include <netlink/netlink.h>
16 #include <netlink/cache.h>
17 #include <netlink/utils.h>
18 #include <netlink/data.h>
19 #include <netlink/route/rtnl.h>
20 #include <netlink/route/route.h>
21 #include <netlink/route/link.h>
22 
23 #include "nl-route.h"
24 #include "nl-priv-dynamic-core/nl-core.h"
25 #include "nl-priv-dynamic-core/cache-api.h"
26 #include "nl-aux-route/nl-route.h"
27 
28 static struct nl_cache_ops rtnl_route_ops;
29 
route_msg_parser(struct nl_cache_ops * ops,struct sockaddr_nl * who,struct nlmsghdr * nlh,struct nl_parser_param * pp)30 static int route_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
31 			    struct nlmsghdr *nlh, struct nl_parser_param *pp)
32 {
33 	struct rtnl_route *route;
34 	int err;
35 
36 	if ((err = rtnl_route_parse(nlh, &route)) < 0)
37 		return err;
38 
39 	err = pp->pp_cb((struct nl_object *) route, pp);
40 
41 	rtnl_route_put(route);
42 	return err;
43 }
44 
route_request_update(struct nl_cache * c,struct nl_sock * h)45 static int route_request_update(struct nl_cache *c, struct nl_sock *h)
46 {
47 	struct rtmsg rhdr = {
48 		.rtm_family = c->c_iarg1,
49 	};
50 
51 	if (c->c_iarg2 & ROUTE_CACHE_CONTENT)
52 		rhdr.rtm_flags |= RTM_F_CLONED;
53 
54 	return nl_send_simple(h, RTM_GETROUTE, NLM_F_DUMP, &rhdr, sizeof(rhdr));
55 }
56 
57 /**
58  * @name Cache Management
59  * @{
60  */
61 
62 /**
63  * Build a route cache holding all routes currently configured in the kernel
64  * @arg sk		Netlink socket.
65  * @arg family		Address family of routes to cover or AF_UNSPEC
66  * @arg flags		Flags
67  * @arg result		Result pointer
68  *
69  * Allocates a new cache, initializes it properly and updates it to
70  * contain all routes currently configured in the kernel.
71  *
72  * Valid flags:
73  *   * ROUTE_CACHE_CONTENT - Cache will contain contents of routing cache
74  *                           instead of actual routes.
75  *
76  * @note The caller is responsible for destroying and freeing the
77  *       cache after using it.
78  * @return 0 on success or a negative error code.
79  */
rtnl_route_alloc_cache(struct nl_sock * sk,int family,int flags,struct nl_cache ** result)80 int rtnl_route_alloc_cache(struct nl_sock *sk, int family, int flags,
81 			   struct nl_cache **result)
82 {
83 	struct nl_cache *cache;
84 	int err;
85 
86 	if (!(cache = nl_cache_alloc(&rtnl_route_ops)))
87 		return -NLE_NOMEM;
88 
89 	cache->c_iarg1 = family;
90 	cache->c_iarg2 = flags;
91 
92 	if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
93 		free(cache);
94 		return err;
95 	}
96 
97 	*result = cache;
98 	return 0;
99 }
100 
101 /** @} */
102 
103 /**
104  * @name Route Addition
105  * @{
106  */
107 
build_route_msg(struct rtnl_route * tmpl,int cmd,int flags,struct nl_msg ** result)108 static int build_route_msg(struct rtnl_route *tmpl, int cmd, int flags,
109 			   struct nl_msg **result)
110 {
111 	struct nl_msg *msg;
112 	int err;
113 
114 	if (!(msg = nlmsg_alloc_simple(cmd, flags)))
115 		return -NLE_NOMEM;
116 
117 	if ((err = rtnl_route_build_msg(msg, tmpl)) < 0) {
118 		nlmsg_free(msg);
119 		return err;
120 	}
121 
122 	*result = msg;
123 	return 0;
124 }
125 
rtnl_route_build_add_request(struct rtnl_route * tmpl,int flags,struct nl_msg ** result)126 int rtnl_route_build_add_request(struct rtnl_route *tmpl, int flags,
127 				 struct nl_msg **result)
128 {
129 	return build_route_msg(tmpl, RTM_NEWROUTE, NLM_F_CREATE | flags,
130 			       result);
131 }
132 
rtnl_route_lookup(struct nl_sock * sk,struct nl_addr * dst,struct rtnl_route ** result)133 int rtnl_route_lookup(struct nl_sock *sk, struct nl_addr *dst,
134                       struct rtnl_route **result)
135 {
136 	_nl_auto_nl_msg struct nl_msg *msg = NULL;
137 	_nl_auto_rtnl_route struct rtnl_route *tmpl = NULL;
138 	struct nl_object *obj;
139 	int err;
140 
141 	tmpl = rtnl_route_alloc();
142 	rtnl_route_set_dst(tmpl, dst);
143 	err = build_route_msg(tmpl, RTM_GETROUTE, 0, &msg);
144 	if (err < 0)
145 		return err;
146 
147 	err = nl_send_auto(sk, msg);
148 	if (err < 0)
149 		return err;
150 
151 	if ((err = nl_pickup(sk, route_msg_parser, &obj)) < 0)
152 		return err;
153 
154 	*result = (struct rtnl_route *)obj;
155 	wait_for_ack(sk);
156 	return 0;
157 }
158 
rtnl_route_add(struct nl_sock * sk,struct rtnl_route * route,int flags)159 int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
160 {
161 	struct nl_msg *msg;
162 	int err;
163 
164 	if ((err = rtnl_route_build_add_request(route, flags, &msg)) < 0)
165 		return err;
166 
167 	err = nl_send_auto_complete(sk, msg);
168 	nlmsg_free(msg);
169 	if (err < 0)
170 		return err;
171 
172 	return wait_for_ack(sk);
173 }
174 
rtnl_route_build_del_request(struct rtnl_route * tmpl,int flags,struct nl_msg ** result)175 int rtnl_route_build_del_request(struct rtnl_route *tmpl, int flags,
176 				 struct nl_msg **result)
177 {
178 	return build_route_msg(tmpl, RTM_DELROUTE, flags, result);
179 }
180 
rtnl_route_delete(struct nl_sock * sk,struct rtnl_route * route,int flags)181 int rtnl_route_delete(struct nl_sock *sk, struct rtnl_route *route, int flags)
182 {
183 	struct nl_msg *msg;
184 	int err;
185 
186 	if ((err = rtnl_route_build_del_request(route, flags, &msg)) < 0)
187 		return err;
188 
189 	err = nl_send_auto_complete(sk, msg);
190 	nlmsg_free(msg);
191 	if (err < 0)
192 		return err;
193 
194 	return wait_for_ack(sk);
195 }
196 
197 /** @} */
198 
199 static struct nl_af_group route_groups[] = {
200 	{ AF_INET,	RTNLGRP_IPV4_ROUTE },
201 	{ AF_INET6,	RTNLGRP_IPV6_ROUTE },
202 	{ AF_MPLS,	RTNLGRP_MPLS_ROUTE },
203 	{ AF_DECnet,	RTNLGRP_DECnet_ROUTE },
204 	{ END_OF_GROUP_LIST },
205 };
206 
207 static struct nl_cache_ops rtnl_route_ops = {
208 	.co_name		= "route/route",
209 	.co_hdrsize		= sizeof(struct rtmsg),
210 	.co_msgtypes		= {
211 					{ RTM_NEWROUTE, NL_ACT_NEW, "new" },
212 					{ RTM_DELROUTE, NL_ACT_DEL, "del" },
213 					{ RTM_GETROUTE, NL_ACT_GET, "get" },
214 					END_OF_MSGTYPES_LIST,
215 				  },
216 	.co_protocol		= NETLINK_ROUTE,
217 	.co_groups		= route_groups,
218 	.co_request_update	= route_request_update,
219 	.co_msg_parser		= route_msg_parser,
220 	.co_obj_ops		= &route_obj_ops,
221 };
222 
route_init(void)223 static void _nl_init route_init(void)
224 {
225 	nl_cache_mngt_register(&rtnl_route_ops);
226 }
227 
route_exit(void)228 static void _nl_exit route_exit(void)
229 {
230 	nl_cache_mngt_unregister(&rtnl_route_ops);
231 }
232 
233 /** @} */
234