libnl 3.5.0

inet.c
1 /*
2 * lib/route/link/inet.c AF_INET link operations
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) 2010 Thomas Graf <tgraf@suug.ch>
10 */
11
12 /**
13 * @ingroup link_API
14 * @defgroup link_inet IPv4 Link Module
15 * @brief Implementation of IPv4 specific link attributes
16 *
17 *
18 *
19 * @par Example: Reading the value of IPV4_DEVCONF_FORWARDING
20 * @code
21 * struct nl_cache *cache;
22 * struct rtnl_link *link;
23 * uint32_t value;
24 *
25 * // Allocate a link cache
26 * rtnl_link_alloc_cache(sock, AF_UNSPEC, &cache);
27 *
28 * // Search for the link we wish to see the value from
29 * link = rtnl_link_get_by_name(cache, "eth0");
30 *
31 * // Read the value of the setting IPV4_DEVCONF_FORWARDING
32 * if (rtnl_link_inet_get_conf(link, IPV4_DEVCONF_FORWARDING, &value) < 0)
33 * // Error: Unable to read config setting
34 *
35 * printf("forwarding is %s\n", value ? "enabled" : "disabled");
36 * @endcode
37 *
38 * @par Example: Changing the value of IPV4_DEVCONF_FOWARDING
39 * @code
40 * //
41 * // ... Continueing from the previous example ...
42 * //
43 *
44 * struct rtnl_link *new;
45 *
46 * // Allocate a new link to store the changes we wish to make.
47 * new = rtnl_link_alloc();
48 *
49 * // Set IPV4_DEVCONF_FORWARDING to '1'
50 * rtnl_link_inet_set_conf(new, IPV4_DEVCONF_FORWARDING, 1);
51 *
52 * // Send the change request to the kernel.
53 * rtnl_link_change(sock, link, new, 0);
54 * @endcode
55 *
56 * @{
57 */
58
59
60 #include <netlink-private/netlink.h>
61 #include <netlink/netlink.h>
62 #include <netlink/attr.h>
63 #include <netlink/route/rtnl.h>
64 #include <netlink/route/link/inet.h>
65 #include <netlink-private/route/link/api.h>
66
67 /** @cond SKIP */
68 struct inet_data
69 {
70 uint8_t i_confset[IPV4_DEVCONF_MAX];
71 uint32_t i_conf[IPV4_DEVCONF_MAX];
72 };
73 /** @endcond */
74
75 static void *inet_alloc(struct rtnl_link *link)
76 {
77 return calloc(1, sizeof(struct inet_data));
78 }
79
80 static void *inet_clone(struct rtnl_link *link, void *data)
81 {
82 struct inet_data *id;
83
84 if ((id = inet_alloc(link)))
85 memcpy(id, data, sizeof(*id));
86
87 return id;
88 }
89
90 static void inet_free(struct rtnl_link *link, void *data)
91 {
92 free(data);
93 }
94
95 static struct nla_policy inet_policy[IFLA_INET_MAX+1] = {
96 [IFLA_INET_CONF] = { .minlen = 4 },
97 };
98
99 static int inet_parse_af(struct rtnl_link *link, struct nlattr *attr, void *data)
100 {
101 struct inet_data *id = data;
102 struct nlattr *tb[IFLA_INET_MAX+1];
103 int err;
104
105 err = nla_parse_nested(tb, IFLA_INET_MAX, attr, inet_policy);
106 if (err < 0)
107 return err;
108 if (tb[IFLA_INET_CONF] && nla_len(tb[IFLA_INET_CONF]) % 4)
109 return -EINVAL;
110
111 if (tb[IFLA_INET_CONF]) {
112 int i;
113 int len = min_t(int, IPV4_DEVCONF_MAX, nla_len(tb[IFLA_INET_CONF]) / 4);
114
115 for (i = 0; i < len; i++)
116 id->i_confset[i] = 1;
117 nla_memcpy(&id->i_conf, tb[IFLA_INET_CONF], sizeof(id->i_conf));
118 }
119
120 return 0;
121 }
122
123 static int inet_fill_af(struct rtnl_link *link, struct nl_msg *msg, void *data)
124 {
125 struct inet_data *id = data;
126 struct nlattr *nla;
127 int i;
128
129 if (!(nla = nla_nest_start(msg, IFLA_INET_CONF)))
130 return -NLE_MSGSIZE;
131
132 for (i = 0; i < IPV4_DEVCONF_MAX; i++)
133 if (id->i_confset[i])
134 NLA_PUT_U32(msg, i+1, id->i_conf[i]);
135
136 nla_nest_end(msg, nla);
137
138 return 0;
139
140 nla_put_failure:
141 return -NLE_MSGSIZE;
142 }
143
144 static const struct trans_tbl inet_devconf[] = {
145 __ADD(IPV4_DEVCONF_FORWARDING, forwarding),
146 __ADD(IPV4_DEVCONF_MC_FORWARDING, mc_forwarding),
147 __ADD(IPV4_DEVCONF_PROXY_ARP, proxy_arp),
148 __ADD(IPV4_DEVCONF_ACCEPT_REDIRECTS, accept_redirects),
149 __ADD(IPV4_DEVCONF_SECURE_REDIRECTS, secure_redirects),
150 __ADD(IPV4_DEVCONF_SEND_REDIRECTS, send_redirects),
151 __ADD(IPV4_DEVCONF_SHARED_MEDIA, shared_media),
152 __ADD(IPV4_DEVCONF_RP_FILTER, rp_filter),
153 __ADD(IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE, accept_source_route),
154 __ADD(IPV4_DEVCONF_BOOTP_RELAY, bootp_relay),
155 __ADD(IPV4_DEVCONF_LOG_MARTIANS, log_martians),
156 __ADD(IPV4_DEVCONF_TAG, tag),
157 __ADD(IPV4_DEVCONF_ARPFILTER, arpfilter),
158 __ADD(IPV4_DEVCONF_MEDIUM_ID, medium_id),
159 __ADD(IPV4_DEVCONF_NOXFRM, noxfrm),
160 __ADD(IPV4_DEVCONF_NOPOLICY, nopolicy),
161 __ADD(IPV4_DEVCONF_FORCE_IGMP_VERSION, force_igmp_version),
162 __ADD(IPV4_DEVCONF_ARP_ANNOUNCE, arp_announce),
163 __ADD(IPV4_DEVCONF_ARP_IGNORE, arp_ignore),
164 __ADD(IPV4_DEVCONF_PROMOTE_SECONDARIES, promote_secondaries),
165 __ADD(IPV4_DEVCONF_ARP_ACCEPT, arp_accept),
166 __ADD(IPV4_DEVCONF_ARP_NOTIFY, arp_notify),
167 __ADD(IPV4_DEVCONF_ACCEPT_LOCAL, accept_local),
168 __ADD(IPV4_DEVCONF_SRC_VMARK, src_vmark),
169 __ADD(IPV4_DEVCONF_PROXY_ARP_PVLAN, proxy_arp_pvlan),
170 __ADD(IPV4_DEVCONF_ROUTE_LOCALNET, route_localnet),
171 __ADD(IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL, igmpv2_unsolicited_report_interval),
172 __ADD(IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL, igmpv3_unsolicited_report_interval),
173 };
174
175 const char *rtnl_link_inet_devconf2str(int type, char *buf, size_t len)
176 {
177 return __type2str(type, buf, len, inet_devconf,
178 ARRAY_SIZE(inet_devconf));
179 }
180
181 int rtnl_link_inet_str2devconf(const char *name)
182 {
183 return __str2type(name, inet_devconf, ARRAY_SIZE(inet_devconf));
184 }
185
186 static void inet_dump_details(struct rtnl_link *link,
187 struct nl_dump_params *p, void *data)
188 {
189 struct inet_data *id = data;
190 char buf[64];
191 int i, n = 0;
192
193 nl_dump_line(p, " ipv4 devconf:\n");
194 nl_dump_line(p, " ");
195
196 for (i = 0; i < IPV4_DEVCONF_MAX; i++) {
197 nl_dump_line(p, "%-19s %3u",
198 rtnl_link_inet_devconf2str(i+1, buf, sizeof(buf)),
199 id->i_confset[i] ? id->i_conf[i] : 0);
200
201 if (++n == 3) {
202 nl_dump(p, "\n");
203 nl_dump_line(p, " ");
204 n = 0;
205 } else
206 nl_dump(p, " ");
207 }
208
209 if (n != 0)
210 nl_dump(p, "\n");
211 }
212
213 static struct rtnl_link_af_ops inet_ops = {
214 .ao_family = AF_INET,
215 .ao_alloc = &inet_alloc,
216 .ao_clone = &inet_clone,
217 .ao_free = &inet_free,
218 .ao_parse_af = &inet_parse_af,
219 .ao_fill_af = &inet_fill_af,
220 .ao_dump[NL_DUMP_DETAILS] = &inet_dump_details,
221 };
222
223 /**
224 * Get value of a ipv4 link configuration setting
225 * @arg link Link object
226 * @arg cfgid Configuration identifier
227 * @arg res Result pointer
228 *
229 * Stores the value of the specified configuration setting in the provided
230 * result pointer.
231 *
232 * @return 0 on success or a negative error code.
233 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
234 * @return -NLE_NOATTR configuration setting not available
235 * @return -NLE_INVAL cfgid not set. If the link was received via netlink,
236 * it means that the cfgid is not supported.
237 */
238 int rtnl_link_inet_get_conf(struct rtnl_link *link, const unsigned int cfgid,
239 uint32_t *res)
240 {
241 struct inet_data *id;
242
243 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
244 return -NLE_RANGE;
245
246 if (!(id = rtnl_link_af_data(link, &inet_ops)))
247 return -NLE_NOATTR;
248
249 if (!id->i_confset[cfgid - 1])
250 return -NLE_INVAL;
251 *res = id->i_conf[cfgid - 1];
252
253 return 0;
254 }
255
256 /**
257 * Change value of a ipv4 link configuration setting
258 * @arg link Link object
259 * @arg cfgid Configuration identifier
260 * @arg value New value
261 *
262 * Changes the value in the per link ipv4 configuration array.
263 *
264 * @return 0 on success or a negative error code.
265 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
266 * @return -NLE_NOMEM memory allocation failed
267 */
268 int rtnl_link_inet_set_conf(struct rtnl_link *link, const unsigned int cfgid,
269 uint32_t value)
270 {
271 struct inet_data *id;
272
273 if (!(id = rtnl_link_af_alloc(link, &inet_ops)))
274 return -NLE_NOMEM;
275
276 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
277 return -NLE_RANGE;
278
279 id->i_confset[cfgid - 1] = 1;
280 id->i_conf[cfgid - 1] = value;
281
282 return 0;
283 }
284
285
286 static void __init inet_init(void)
287 {
288 rtnl_link_af_register(&inet_ops);
289 }
290
291 static void __exit inet_exit(void)
292 {
293 rtnl_link_af_unregister(&inet_ops);
294 }
295
296 /** @} */
rtnl_link_af_register
int rtnl_link_af_register(struct rtnl_link_af_ops *ops)
Register operations for a link address family.
Definition: api.c:285
nla_policy
Attribute validation policy.
Definition: attr.h:69
rtnl_link_af_unregister
int rtnl_link_af_unregister(struct rtnl_link_af_ops *ops)
Unregister operations for a link address family.
Definition: api.c:324
rtnl_link
Link object.
NL_DUMP_DETAILS
Dump all attributes but no statistics.
Definition: types.h:23
nla_nest_end
int nla_nest_end(struct nl_msg *msg, struct nlattr *start)
Finalize nesting of attributes.
Definition: attr.c:966
nla_parse_nested
int nla_parse_nested(struct nlattr *tb[], int maxtype, struct nlattr *nla, const struct nla_policy *policy)
Create attribute index based on nested attribute.
Definition: attr.c:1021
nla_memcpy
int nla_memcpy(void *dest, const struct nlattr *src, int count)
Copy attribute payload to another memory area.
Definition: attr.c:354
NLA_PUT_U32
#define NLA_PUT_U32(msg, attrtype, value)
Add 32 bit integer attribute to netlink message.
Definition: attr.h:236
nla_len
int nla_len(const struct nlattr *nla)
Return length of the payload .
Definition: attr.c:132
rtnl_link_af_alloc
void * rtnl_link_af_alloc(struct rtnl_link *link, const struct rtnl_link_af_ops *ops)
Allocate and return data buffer for link address family modules.
Definition: api.c:229
nla_policy::minlen
uint16_t minlen
Minimal length of payload required.
Definition: attr.h:74
rtnl_link_af_data
void * rtnl_link_af_data(const struct rtnl_link *link, const struct rtnl_link_af_ops *ops)
Return data buffer for link address family modules.
Definition: api.c:264
nl_dump_params
Dumping parameters.
Definition: types.h:33
rtnl_link_inet_set_conf
int rtnl_link_inet_set_conf(struct rtnl_link *link, const unsigned int cfgid, uint32_t value)
Change value of a ipv4 link configuration setting.
Definition: inet.c:268
nl_dump
void nl_dump(struct nl_dump_params *params, const char *fmt,...)
Dump a formatted character string.
Definition: utils.c:962
nla_nest_start
struct nlattr * nla_nest_start(struct nl_msg *msg, int attrtype)
Start a new level of nested attributes.
Definition: attr.c:903
rtnl_link_inet_get_conf
int rtnl_link_inet_get_conf(struct rtnl_link *link, const unsigned int cfgid, uint32_t *res)
Get value of a ipv4 link configuration setting.
Definition: inet.c:238