libnl: /data/src/libnl3/lib/route/link/inet.c Source File

libnl 3.7.0

inet.c
1 /* SPDX-License-Identifier: LGPL-2.1-only */
2 /*
3 * Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
4 */
5
6 /**
7 * @ingroup link_API
8 * @defgroup link_inet IPv4 Link Module
9 * @brief Implementation of IPv4 specific link attributes
10 *
11 *
12 *
13 * @par Example: Reading the value of IPV4_DEVCONF_FORWARDING
14 * @code
15 * struct nl_cache *cache;
16 * struct rtnl_link *link;
17 * uint32_t value;
18 *
19 * // Allocate a link cache
20 * rtnl_link_alloc_cache(sock, AF_UNSPEC, &cache);
21 *
22 * // Search for the link we wish to see the value from
23 * link = rtnl_link_get_by_name(cache, "eth0");
24 *
25 * // Read the value of the setting IPV4_DEVCONF_FORWARDING
26 * if (rtnl_link_inet_get_conf(link, IPV4_DEVCONF_FORWARDING, &value) < 0)
27 * // Error: Unable to read config setting
28 *
29 * printf("forwarding is %s\n", value ? "enabled" : "disabled");
30 * @endcode
31 *
32 * @par Example: Changing the value of IPV4_DEVCONF_FOWARDING
33 * @code
34 * //
35 * // ... Continueing from the previous example ...
36 * //
37 *
38 * struct rtnl_link *new;
39 *
40 * // Allocate a new link to store the changes we wish to make.
41 * new = rtnl_link_alloc();
42 *
43 * // Set IPV4_DEVCONF_FORWARDING to '1'
44 * rtnl_link_inet_set_conf(new, IPV4_DEVCONF_FORWARDING, 1);
45 *
46 * // Send the change request to the kernel.
47 * rtnl_link_change(sock, link, new, 0);
48 * @endcode
49 *
50 * @{
51 */
52
53
54 #include <netlink-private/netlink.h>
55 #include <netlink/netlink.h>
56 #include <netlink/attr.h>
57 #include <netlink/route/rtnl.h>
58 #include <netlink/route/link/inet.h>
59 #include <netlink-private/route/link/api.h>
60
61 /** @cond SKIP */
62 struct inet_data
63 {
64 uint8_t i_confset[IPV4_DEVCONF_MAX];
65 uint32_t i_conf[IPV4_DEVCONF_MAX];
66 };
67 /** @endcond */
68
69 static void *inet_alloc(struct rtnl_link *link)
70 {
71 return calloc(1, sizeof(struct inet_data));
72 }
73
74 static void *inet_clone(struct rtnl_link *link, void *data)
75 {
76 struct inet_data *id;
77
78 if ((id = inet_alloc(link)))
79 memcpy(id, data, sizeof(*id));
80
81 return id;
82 }
83
84 static void inet_free(struct rtnl_link *link, void *data)
85 {
86 free(data);
87 }
88
89 static struct nla_policy inet_policy[IFLA_INET_MAX+1] = {
90 [IFLA_INET_CONF] = { .minlen = 4 },
91 };
92
93 static int inet_parse_af(struct rtnl_link *link, struct nlattr *attr, void *data)
94 {
95 struct inet_data *id = data;
96 struct nlattr *tb[IFLA_INET_MAX+1];
97 int err;
98
99 err = nla_parse_nested(tb, IFLA_INET_MAX, attr, inet_policy);
100 if (err < 0)
101 return err;
102 if (tb[IFLA_INET_CONF] && nla_len(tb[IFLA_INET_CONF]) % 4)
103 return -EINVAL;
104
105 if (tb[IFLA_INET_CONF]) {
106 int i;
107 int len = min_t(int, IPV4_DEVCONF_MAX, nla_len(tb[IFLA_INET_CONF]) / 4);
108
109 for (i = 0; i < len; i++)
110 id->i_confset[i] = 1;
111 nla_memcpy(&id->i_conf, tb[IFLA_INET_CONF], sizeof(id->i_conf));
112 }
113
114 return 0;
115 }
116
117 static int inet_fill_af(struct rtnl_link *link, struct nl_msg *msg, void *data)
118 {
119 struct inet_data *id = data;
120 struct nlattr *nla;
121 int i;
122
123 if (!(nla = nla_nest_start(msg, IFLA_INET_CONF)))
124 return -NLE_MSGSIZE;
125
126 for (i = 0; i < IPV4_DEVCONF_MAX; i++)
127 if (id->i_confset[i])
128 NLA_PUT_U32(msg, i+1, id->i_conf[i]);
129
130 nla_nest_end(msg, nla);
131
132 return 0;
133
134 nla_put_failure:
135 return -NLE_MSGSIZE;
136 }
137
138 static const struct trans_tbl inet_devconf[] = {
139 __ADD(IPV4_DEVCONF_FORWARDING, forwarding),
140 __ADD(IPV4_DEVCONF_MC_FORWARDING, mc_forwarding),
141 __ADD(IPV4_DEVCONF_PROXY_ARP, proxy_arp),
142 __ADD(IPV4_DEVCONF_ACCEPT_REDIRECTS, accept_redirects),
143 __ADD(IPV4_DEVCONF_SECURE_REDIRECTS, secure_redirects),
144 __ADD(IPV4_DEVCONF_SEND_REDIRECTS, send_redirects),
145 __ADD(IPV4_DEVCONF_SHARED_MEDIA, shared_media),
146 __ADD(IPV4_DEVCONF_RP_FILTER, rp_filter),
147 __ADD(IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE, accept_source_route),
148 __ADD(IPV4_DEVCONF_BOOTP_RELAY, bootp_relay),
149 __ADD(IPV4_DEVCONF_LOG_MARTIANS, log_martians),
150 __ADD(IPV4_DEVCONF_TAG, tag),
151 __ADD(IPV4_DEVCONF_ARPFILTER, arpfilter),
152 __ADD(IPV4_DEVCONF_MEDIUM_ID, medium_id),
153 __ADD(IPV4_DEVCONF_NOXFRM, noxfrm),
154 __ADD(IPV4_DEVCONF_NOPOLICY, nopolicy),
155 __ADD(IPV4_DEVCONF_FORCE_IGMP_VERSION, force_igmp_version),
156 __ADD(IPV4_DEVCONF_ARP_ANNOUNCE, arp_announce),
157 __ADD(IPV4_DEVCONF_ARP_IGNORE, arp_ignore),
158 __ADD(IPV4_DEVCONF_PROMOTE_SECONDARIES, promote_secondaries),
159 __ADD(IPV4_DEVCONF_ARP_ACCEPT, arp_accept),
160 __ADD(IPV4_DEVCONF_ARP_NOTIFY, arp_notify),
161 __ADD(IPV4_DEVCONF_ACCEPT_LOCAL, accept_local),
162 __ADD(IPV4_DEVCONF_SRC_VMARK, src_vmark),
163 __ADD(IPV4_DEVCONF_PROXY_ARP_PVLAN, proxy_arp_pvlan),
164 __ADD(IPV4_DEVCONF_ROUTE_LOCALNET, route_localnet),
165 __ADD(IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL, igmpv2_unsolicited_report_interval),
166 __ADD(IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL, igmpv3_unsolicited_report_interval),
167 };
168
169 const char *rtnl_link_inet_devconf2str(int type, char *buf, size_t len)
170 {
171 return __type2str(type, buf, len, inet_devconf,
172 ARRAY_SIZE(inet_devconf));
173 }
174
175 int rtnl_link_inet_str2devconf(const char *name)
176 {
177 return __str2type(name, inet_devconf, ARRAY_SIZE(inet_devconf));
178 }
179
180 static void inet_dump_details(struct rtnl_link *link,
181 struct nl_dump_params *p, void *data)
182 {
183 struct inet_data *id = data;
184 char buf[64];
185 int i, n = 0;
186
187 nl_dump_line(p, " ipv4 devconf:\n");
188 nl_dump_line(p, " ");
189
190 for (i = 0; i < IPV4_DEVCONF_MAX; i++) {
191 nl_dump_line(p, "%-19s %3u",
192 rtnl_link_inet_devconf2str(i+1, buf, sizeof(buf)),
193 id->i_confset[i] ? id->i_conf[i] : 0);
194
195 if (++n == 3) {
196 nl_dump(p, "\n");
197 nl_dump_line(p, " ");
198 n = 0;
199 } else
200 nl_dump(p, " ");
201 }
202
203 if (n != 0)
204 nl_dump(p, "\n");
205 }
206
207 static struct rtnl_link_af_ops inet_ops = {
208 .ao_family = AF_INET,
209 .ao_alloc = &inet_alloc,
210 .ao_clone = &inet_clone,
211 .ao_free = &inet_free,
212 .ao_parse_af = &inet_parse_af,
213 .ao_fill_af = &inet_fill_af,
214 .ao_dump[NL_DUMP_DETAILS] = &inet_dump_details,
215 };
216
217 /**
218 * Get value of a ipv4 link configuration setting
219 * @arg link Link object
220 * @arg cfgid Configuration identifier
221 * @arg res Result pointer
222 *
223 * Stores the value of the specified configuration setting in the provided
224 * result pointer.
225 *
226 * @return 0 on success or a negative error code.
227 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
228 * @return -NLE_NOATTR configuration setting not available
229 * @return -NLE_INVAL cfgid not set. If the link was received via netlink,
230 * it means that the cfgid is not supported.
231 */
232 int rtnl_link_inet_get_conf(struct rtnl_link *link, const unsigned int cfgid,
233 uint32_t *res)
234 {
235 struct inet_data *id;
236
237 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
238 return -NLE_RANGE;
239
240 if (!(id = rtnl_link_af_data(link, &inet_ops)))
241 return -NLE_NOATTR;
242
243 if (!id->i_confset[cfgid - 1])
244 return -NLE_INVAL;
245 *res = id->i_conf[cfgid - 1];
246
247 return 0;
248 }
249
250 /**
251 * Change value of a ipv4 link configuration setting
252 * @arg link Link object
253 * @arg cfgid Configuration identifier
254 * @arg value New value
255 *
256 * Changes the value in the per link ipv4 configuration array.
257 *
258 * @return 0 on success or a negative error code.
259 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
260 * @return -NLE_NOMEM memory allocation failed
261 */
262 int rtnl_link_inet_set_conf(struct rtnl_link *link, const unsigned int cfgid,
263 uint32_t value)
264 {
265 struct inet_data *id;
266
267 if (!(id = rtnl_link_af_alloc(link, &inet_ops)))
268 return -NLE_NOMEM;
269
270 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
271 return -NLE_RANGE;
272
273 id->i_confset[cfgid - 1] = 1;
274 id->i_conf[cfgid - 1] = value;
275
276 return 0;
277 }
278
279
280 static void __init inet_init(void)
281 {
282 rtnl_link_af_register(&inet_ops);
283 }
284
285 static void __exit inet_exit(void)
286 {
287 rtnl_link_af_unregister(&inet_ops);
288 }
289
290 /** @} */
NLA_PUT_U32
#define NLA_PUT_U32(msg, attrtype, value)
Add 32 bit integer attribute to netlink message.
Definition: attr.h:230
nla_memcpy
int nla_memcpy(void *dest, const struct nlattr *src, int count)
Copy attribute payload to another memory area.
Definition: attr.c:346
nla_nest_start
struct nlattr * nla_nest_start(struct nl_msg *msg, int attrtype)
Start a new level of nested attributes.
Definition: attr.c:895
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:1013
nla_len
int nla_len(const struct nlattr *nla)
Return length of the payload .
Definition: attr.c:125
nla_nest_end
int nla_nest_end(struct nl_msg *msg, struct nlattr *start)
Finalize nesting of attributes.
Definition: attr.c:958
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:341
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:302
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:281
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:246
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:232
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:262
nl_dump
void nl_dump(struct nl_dump_params *params, const char *fmt,...)
Dump a formatted character string.
Definition: utils.c:955
NL_DUMP_DETAILS
@ NL_DUMP_DETAILS
Dump all attributes but no statistics.
Definition: types.h:17
nl_dump_params
Dumping parameters.
Definition: types.h:28
nla_policy
Attribute validation policy.
Definition: attr.h:63
nla_policy::minlen
uint16_t minlen
Minimal length of payload required.
Definition: attr.h:68
rtnl_link
Link object.