libnl 3.5.0

route.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3 * lib/route/route.c Routes
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation version 2.1
8 * of the License.
9 *
10 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
11 */
12
13 /**
14 * @ingroup rtnl
15 * @defgroup route Routing
16 * @brief
17 * @{
18 */
19
20 #include <netlink-private/netlink.h>
21 #include <netlink/netlink.h>
22 #include <netlink/cache.h>
23 #include <netlink/utils.h>
24 #include <netlink/data.h>
25 #include <netlink/route/rtnl.h>
26 #include <netlink/route/route.h>
27 #include <netlink/route/link.h>
28
29 static struct nl_cache_ops rtnl_route_ops;
30
31 static int route_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
32 struct nlmsghdr *nlh, struct nl_parser_param *pp)
33 {
34 struct rtnl_route *route;
35 int err;
36
37 if ((err = rtnl_route_parse(nlh, &route)) < 0)
38 return err;
39
40 err = pp->pp_cb((struct nl_object *) route, pp);
41
42 rtnl_route_put(route);
43 return err;
44 }
45
46 static int route_request_update(struct nl_cache *c, struct nl_sock *h)
47 {
48 struct rtmsg rhdr = {
49 .rtm_family = c->c_iarg1,
50 };
51
52 if (c->c_iarg2 & ROUTE_CACHE_CONTENT)
53 rhdr.rtm_flags |= RTM_F_CLONED;
54
55 return nl_send_simple(h, RTM_GETROUTE, NLM_F_DUMP, &rhdr, sizeof(rhdr));
56 }
57
58 /**
59 * @name Cache Management
60 * @{
61 */
62
63 /**
64 * Build a route cache holding all routes currently configured in the kernel
65 * @arg sk Netlink socket.
66 * @arg family Address family of routes to cover or AF_UNSPEC
67 * @arg flags Flags
68 * @arg result Result pointer
69 *
70 * Allocates a new cache, initializes it properly and updates it to
71 * contain all routes currently configured in the kernel.
72 *
73 * Valid flags:
74 * * ROUTE_CACHE_CONTENT - Cache will contain contents of routing cache
75 * instead of actual routes.
76 *
77 * @note The caller is responsible for destroying and freeing the
78 * cache after using it.
79 * @return 0 on success or a negative error code.
80 */
81 int rtnl_route_alloc_cache(struct nl_sock *sk, int family, int flags,
82 struct nl_cache **result)
83 {
84 struct nl_cache *cache;
85 int err;
86
87 if (!(cache = nl_cache_alloc(&rtnl_route_ops)))
88 return -NLE_NOMEM;
89
90 cache->c_iarg1 = family;
91 cache->c_iarg2 = flags;
92
93 if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
94 free(cache);
95 return err;
96 }
97
98 *result = cache;
99 return 0;
100 }
101
102 /** @} */
103
104 /**
105 * @name Route Addition
106 * @{
107 */
108
109 static int build_route_msg(struct rtnl_route *tmpl, int cmd, int flags,
110 struct nl_msg **result)
111 {
112 struct nl_msg *msg;
113 int err;
114
115 if (!(msg = nlmsg_alloc_simple(cmd, flags)))
116 return -NLE_NOMEM;
117
118 if ((err = rtnl_route_build_msg(msg, tmpl)) < 0) {
119 nlmsg_free(msg);
120 return err;
121 }
122
123 *result = msg;
124 return 0;
125 }
126
127 int rtnl_route_build_add_request(struct rtnl_route *tmpl, int flags,
128 struct nl_msg **result)
129 {
130 return build_route_msg(tmpl, RTM_NEWROUTE, NLM_F_CREATE | flags,
131 result);
132 }
133
134 int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
135 {
136 struct nl_msg *msg;
137 int err;
138
139 if ((err = rtnl_route_build_add_request(route, flags, &msg)) < 0)
140 return err;
141
142 err = nl_send_auto_complete(sk, msg);
143 nlmsg_free(msg);
144 if (err < 0)
145 return err;
146
147 return wait_for_ack(sk);
148 }
149
150 int rtnl_route_build_del_request(struct rtnl_route *tmpl, int flags,
151 struct nl_msg **result)
152 {
153 return build_route_msg(tmpl, RTM_DELROUTE, flags, result);
154 }
155
156 int rtnl_route_delete(struct nl_sock *sk, struct rtnl_route *route, int flags)
157 {
158 struct nl_msg *msg;
159 int err;
160
161 if ((err = rtnl_route_build_del_request(route, flags, &msg)) < 0)
162 return err;
163
164 err = nl_send_auto_complete(sk, msg);
165 nlmsg_free(msg);
166 if (err < 0)
167 return err;
168
169 return wait_for_ack(sk);
170 }
171
172 /** @} */
173
174 static struct nl_af_group route_groups[] = {
175 { AF_INET, RTNLGRP_IPV4_ROUTE },
176 { AF_INET6, RTNLGRP_IPV6_ROUTE },
177 { AF_MPLS, RTNLGRP_MPLS_ROUTE },
178 { AF_DECnet, RTNLGRP_DECnet_ROUTE },
179 { END_OF_GROUP_LIST },
180 };
181
182 static struct nl_cache_ops rtnl_route_ops = {
183 .co_name = "route/route",
184 .co_hdrsize = sizeof(struct rtmsg),
185 .co_msgtypes = {
186 { RTM_NEWROUTE, NL_ACT_NEW, "new" },
187 { RTM_DELROUTE, NL_ACT_DEL, "del" },
188 { RTM_GETROUTE, NL_ACT_GET, "get" },
189 END_OF_MSGTYPES_LIST,
190 },
191 .co_protocol = NETLINK_ROUTE,
192 .co_groups = route_groups,
193 .co_request_update = route_request_update,
194 .co_msg_parser = route_msg_parser,
195 .co_obj_ops = &route_obj_ops,
196 };
197
198 static void __init route_init(void)
199 {
200 nl_cache_mngt_register(&rtnl_route_ops);
201 }
202
203 static void __exit route_exit(void)
204 {
205 nl_cache_mngt_unregister(&rtnl_route_ops);
206 }
207
208 /** @} */
nl_send_auto_complete
int nl_send_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
Definition: nl.c:1248
nlmsg_free
void nlmsg_free(struct nl_msg *msg)
Release a reference from an netlink message.
Definition: msg.c:565
nl_cache_mngt_unregister
int nl_cache_mngt_unregister(struct nl_cache_ops *ops)
Unregister a set of cache operations.
Definition: cache_mngt.c:288
ROUTE_CACHE_CONTENT
#define ROUTE_CACHE_CONTENT
When passed to rtnl_route_alloc_cache() the cache will correspond to the contents of the routing cach...
Definition: route.h:33
nl_cache_mngt_register
int nl_cache_mngt_register(struct nl_cache_ops *ops)
Register a set of cache operations.
Definition: cache_mngt.c:253
nl_send_simple
int nl_send_simple(struct nl_sock *sk, int type, int flags, void *buf, size_t size)
Construct and transmit a Netlink message.
Definition: nl.c:581
nl_cache_refill
int nl_cache_refill(struct nl_sock *sk, struct nl_cache *cache)
(Re)fill a cache with the contents in the kernel.
Definition: cache.c:1041
nlmsg_alloc_simple
struct nl_msg * nlmsg_alloc_simple(int nlmsgtype, int flags)
Allocate a new netlink message.
Definition: msg.c:348
rtnl_route_alloc_cache
int rtnl_route_alloc_cache(struct nl_sock *sk, int family, int flags, struct nl_cache **result)
Build a route cache holding all routes currently configured in the kernel.
Definition: route.c:81
nl_cache_alloc
struct nl_cache * nl_cache_alloc(struct nl_cache_ops *ops)
Allocate new cache.
Definition: cache.c:184