libnl  3.7.0
route.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
4  */
5 
6 /**
7  * @ingroup rtnl
8  * @defgroup route Routing
9  * @brief
10  * @{
11  */
12 
13 #include <netlink-private/netlink.h>
14 #include <netlink-private/nl-auto.h>
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 static struct nl_cache_ops rtnl_route_ops;
24 
25 static int route_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
26  struct nlmsghdr *nlh, struct nl_parser_param *pp)
27 {
28  struct rtnl_route *route;
29  int err;
30 
31  if ((err = rtnl_route_parse(nlh, &route)) < 0)
32  return err;
33 
34  err = pp->pp_cb((struct nl_object *) route, pp);
35 
36  rtnl_route_put(route);
37  return err;
38 }
39 
40 static int route_request_update(struct nl_cache *c, struct nl_sock *h)
41 {
42  struct rtmsg rhdr = {
43  .rtm_family = c->c_iarg1,
44  };
45 
46  if (c->c_iarg2 & ROUTE_CACHE_CONTENT)
47  rhdr.rtm_flags |= RTM_F_CLONED;
48 
49  return nl_send_simple(h, RTM_GETROUTE, NLM_F_DUMP, &rhdr, sizeof(rhdr));
50 }
51 
52 /**
53  * @name Cache Management
54  * @{
55  */
56 
57 /**
58  * Build a route cache holding all routes currently configured in the kernel
59  * @arg sk Netlink socket.
60  * @arg family Address family of routes to cover or AF_UNSPEC
61  * @arg flags Flags
62  * @arg result Result pointer
63  *
64  * Allocates a new cache, initializes it properly and updates it to
65  * contain all routes currently configured in the kernel.
66  *
67  * Valid flags:
68  * * ROUTE_CACHE_CONTENT - Cache will contain contents of routing cache
69  * instead of actual routes.
70  *
71  * @note The caller is responsible for destroying and freeing the
72  * cache after using it.
73  * @return 0 on success or a negative error code.
74  */
75 int rtnl_route_alloc_cache(struct nl_sock *sk, int family, int flags,
76  struct nl_cache **result)
77 {
78  struct nl_cache *cache;
79  int err;
80 
81  if (!(cache = nl_cache_alloc(&rtnl_route_ops)))
82  return -NLE_NOMEM;
83 
84  cache->c_iarg1 = family;
85  cache->c_iarg2 = flags;
86 
87  if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
88  free(cache);
89  return err;
90  }
91 
92  *result = cache;
93  return 0;
94 }
95 
96 /** @} */
97 
98 /**
99  * @name Route Addition
100  * @{
101  */
102 
103 static int build_route_msg(struct rtnl_route *tmpl, int cmd, int flags,
104  struct nl_msg **result)
105 {
106  struct nl_msg *msg;
107  int err;
108 
109  if (!(msg = nlmsg_alloc_simple(cmd, flags)))
110  return -NLE_NOMEM;
111 
112  if ((err = rtnl_route_build_msg(msg, tmpl)) < 0) {
113  nlmsg_free(msg);
114  return err;
115  }
116 
117  *result = msg;
118  return 0;
119 }
120 
121 int rtnl_route_build_add_request(struct rtnl_route *tmpl, int flags,
122  struct nl_msg **result)
123 {
124  return build_route_msg(tmpl, RTM_NEWROUTE, NLM_F_CREATE | flags,
125  result);
126 }
127 
128 int rtnl_route_lookup(struct nl_sock *sk, struct nl_addr *dst,
129  struct rtnl_route **result)
130 {
131  _nl_auto_nl_msg struct nl_msg *msg = NULL;
132  _nl_auto_rtnl_route struct rtnl_route *tmpl = NULL;
133  struct nl_object *obj;
134  int err;
135 
136  tmpl = rtnl_route_alloc();
137  rtnl_route_set_dst(tmpl, dst);
138  err = build_route_msg(tmpl, RTM_GETROUTE, 0, &msg);
139  if (err < 0)
140  return err;
141 
142  err = nl_send_auto(sk, msg);
143  if (err < 0)
144  return err;
145 
146  if ((err = nl_pickup(sk, route_msg_parser, &obj)) < 0)
147  return err;
148 
149  *result = (struct rtnl_route *)obj;
150  wait_for_ack(sk);
151  return 0;
152 }
153 
154 int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
155 {
156  struct nl_msg *msg;
157  int err;
158 
159  if ((err = rtnl_route_build_add_request(route, flags, &msg)) < 0)
160  return err;
161 
162  err = nl_send_auto_complete(sk, msg);
163  nlmsg_free(msg);
164  if (err < 0)
165  return err;
166 
167  return wait_for_ack(sk);
168 }
169 
170 int rtnl_route_build_del_request(struct rtnl_route *tmpl, int flags,
171  struct nl_msg **result)
172 {
173  return build_route_msg(tmpl, RTM_DELROUTE, flags, result);
174 }
175 
176 int rtnl_route_delete(struct nl_sock *sk, struct rtnl_route *route, int flags)
177 {
178  struct nl_msg *msg;
179  int err;
180 
181  if ((err = rtnl_route_build_del_request(route, flags, &msg)) < 0)
182  return err;
183 
184  err = nl_send_auto_complete(sk, msg);
185  nlmsg_free(msg);
186  if (err < 0)
187  return err;
188 
189  return wait_for_ack(sk);
190 }
191 
192 /** @} */
193 
194 static struct nl_af_group route_groups[] = {
195  { AF_INET, RTNLGRP_IPV4_ROUTE },
196  { AF_INET6, RTNLGRP_IPV6_ROUTE },
197  { AF_MPLS, RTNLGRP_MPLS_ROUTE },
198  { AF_DECnet, RTNLGRP_DECnet_ROUTE },
199  { END_OF_GROUP_LIST },
200 };
201 
202 static struct nl_cache_ops rtnl_route_ops = {
203  .co_name = "route/route",
204  .co_hdrsize = sizeof(struct rtmsg),
205  .co_msgtypes = {
206  { RTM_NEWROUTE, NL_ACT_NEW, "new" },
207  { RTM_DELROUTE, NL_ACT_DEL, "del" },
208  { RTM_GETROUTE, NL_ACT_GET, "get" },
209  END_OF_MSGTYPES_LIST,
210  },
211  .co_protocol = NETLINK_ROUTE,
212  .co_groups = route_groups,
213  .co_request_update = route_request_update,
214  .co_msg_parser = route_msg_parser,
215  .co_obj_ops = &route_obj_ops,
216 };
217 
218 static void __init route_init(void)
219 {
220  nl_cache_mngt_register(&rtnl_route_ops);
221 }
222 
223 static void __exit route_exit(void)
224 {
225  nl_cache_mngt_unregister(&rtnl_route_ops);
226 }
227 
228 /** @} */
int nl_cache_mngt_unregister(struct nl_cache_ops *ops)
Unregister a set of cache operations.
Definition: cache_mngt.c:281
int nl_cache_mngt_register(struct nl_cache_ops *ops)
Register a set of cache operations.
Definition: cache_mngt.c:246
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:1035
struct nl_cache * nl_cache_alloc(struct nl_cache_ops *ops)
Allocate new cache.
Definition: cache.c:178
struct nl_msg * nlmsg_alloc_simple(int nlmsgtype, int flags)
Allocate a new netlink message.
Definition: msg.c:341
void nlmsg_free(struct nl_msg *msg)
Release a reference from an netlink message.
Definition: msg.c:558
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:75
#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:27
int nl_send_auto(struct nl_sock *sk, struct nl_msg *msg)
Finalize and transmit Netlink message.
Definition: nl.c:510
int nl_send_auto_complete(struct nl_sock *sk, struct nl_msg *msg)
Definition: nl.c:1241
int nl_pickup(struct nl_sock *sk, int(*parser)(struct nl_cache_ops *, struct sockaddr_nl *, struct nlmsghdr *, struct nl_parser_param *), struct nl_object **result)
Pickup netlink answer, parse is and return object.
Definition: nl.c:1172
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:574