1 /*
2  * lib/route/route.c	Routes
3  *
4  *	This library is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU Lesser General Public
6  *	License as published by the Free Software Foundation version 2.1
7  *	of the License.
8  *
9  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
10  */
11 
12 /**
13  * @ingroup rtnl
14  * @defgroup route Routing
15  * @brief
16  * @{
17  */
18 
19 #include <netlink-local.h>
20 #include <netlink/netlink.h>
21 #include <netlink/cache.h>
22 #include <netlink/utils.h>
23 #include <netlink/data.h>
24 #include <netlink/route/rtnl.h>
25 #include <netlink/route/route.h>
26 #include <netlink/route/link.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  *
68  * Allocates a new cache, initializes it properly and updates it to
69  * contain all routes currently configured in the kernel.
70  *
71  * @note The caller is responsible for destroying and freeing the
72  *       cache after using it.
73  * @return The cache or NULL if an error has occured.
74  */
rtnl_route_alloc_cache(struct nl_sock * sk,int family,int flags,struct nl_cache ** result)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 
build_route_msg(struct rtnl_route * tmpl,int cmd,int flags,struct nl_msg ** result)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 
rtnl_route_build_add_request(struct rtnl_route * tmpl,int flags,struct nl_msg ** result)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 
rtnl_route_add(struct nl_sock * sk,struct rtnl_route * route,int flags)128 int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
129 {
130 	struct nl_msg *msg;
131 	int err;
132 
133 	if ((err = rtnl_route_build_add_request(route, flags, &msg)) < 0)
134 		return err;
135 
136 	err = nl_send_auto_complete(sk, msg);
137 	nlmsg_free(msg);
138 	if (err < 0)
139 		return err;
140 
141 	return wait_for_ack(sk);
142 }
143 
rtnl_route_build_del_request(struct rtnl_route * tmpl,int flags,struct nl_msg ** result)144 int rtnl_route_build_del_request(struct rtnl_route *tmpl, int flags,
145 				 struct nl_msg **result)
146 {
147 	return build_route_msg(tmpl, RTM_DELROUTE, flags, result);
148 }
149 
rtnl_route_delete(struct nl_sock * sk,struct rtnl_route * route,int flags)150 int rtnl_route_delete(struct nl_sock *sk, struct rtnl_route *route, int flags)
151 {
152 	struct nl_msg *msg;
153 	int err;
154 
155 	if ((err = rtnl_route_build_del_request(route, flags, &msg)) < 0)
156 		return err;
157 
158 	err = nl_send_auto_complete(sk, msg);
159 	nlmsg_free(msg);
160 	if (err < 0)
161 		return err;
162 
163 	return wait_for_ack(sk);
164 }
165 
166 /** @} */
167 
168 static struct nl_af_group route_groups[] = {
169 	{ AF_INET,	RTNLGRP_IPV4_ROUTE },
170 	{ AF_INET6,	RTNLGRP_IPV6_ROUTE },
171 	{ AF_DECnet,	RTNLGRP_DECnet_ROUTE },
172 	{ END_OF_GROUP_LIST },
173 };
174 
175 static struct nl_cache_ops rtnl_route_ops = {
176 	.co_name		= "route/route",
177 	.co_hdrsize		= sizeof(struct rtmsg),
178 	.co_msgtypes		= {
179 					{ RTM_NEWROUTE, NL_ACT_NEW, "new" },
180 					{ RTM_DELROUTE, NL_ACT_DEL, "del" },
181 					{ RTM_GETROUTE, NL_ACT_GET, "get" },
182 					END_OF_MSGTYPES_LIST,
183 				  },
184 	.co_protocol		= NETLINK_ROUTE,
185 	.co_groups		= route_groups,
186 	.co_request_update	= route_request_update,
187 	.co_msg_parser		= route_msg_parser,
188 	.co_obj_ops		= &route_obj_ops,
189 };
190 
route_init(void)191 static void __init route_init(void)
192 {
193 	nl_cache_mngt_register(&rtnl_route_ops);
194 }
195 
route_exit(void)196 static void __exit route_exit(void)
197 {
198 	nl_cache_mngt_unregister(&rtnl_route_ops);
199 }
200 
201 /** @} */
202