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-private/route/link/api.h>
65
66 /** @cond SKIP */
67 struct inet_data
68 {
69 uint8_t i_confset[IPV4_DEVCONF_MAX];
70 uint32_t i_conf[IPV4_DEVCONF_MAX];
71 };
72 /** @endcond */
73
inet_alloc(struct rtnl_link * link)74 static void *inet_alloc(struct rtnl_link *link)
75 {
76 return calloc(1, sizeof(struct inet_data));
77 }
78
inet_clone(struct rtnl_link * link,void * data)79 static void *inet_clone(struct rtnl_link *link, void *data)
80 {
81 struct inet_data *id;
82
83 if ((id = inet_alloc(link)))
84 memcpy(id, data, sizeof(*id));
85
86 return id;
87 }
88
inet_free(struct rtnl_link * link,void * data)89 static void inet_free(struct rtnl_link *link, void *data)
90 {
91 free(data);
92 }
93
94 static struct nla_policy inet_policy[IFLA_INET6_MAX+1] = {
95 [IFLA_INET_CONF] = { .minlen = 4 },
96 };
97
inet_parse_af(struct rtnl_link * link,struct nlattr * attr,void * data)98 static int inet_parse_af(struct rtnl_link *link, struct nlattr *attr, void *data)
99 {
100 struct inet_data *id = data;
101 struct nlattr *tb[IFLA_INET_MAX+1];
102 int err;
103
104 err = nla_parse_nested(tb, IFLA_INET_MAX, attr, inet_policy);
105 if (err < 0)
106 return err;
107 if (tb[IFLA_INET_CONF] && nla_len(tb[IFLA_INET_CONF]) % 4)
108 return -EINVAL;
109
110 if (tb[IFLA_INET_CONF]) {
111 int i;
112 int len = min_t(int, IPV4_DEVCONF_MAX, nla_len(tb[IFLA_INET_CONF]) / 4);
113
114 for (i = 0; i < len; i++)
115 id->i_confset[i] = 1;
116 nla_memcpy(&id->i_conf, tb[IFLA_INET_CONF], sizeof(id->i_conf));
117 }
118
119 return 0;
120 }
121
inet_fill_af(struct rtnl_link * link,struct nl_msg * msg,void * data)122 static int inet_fill_af(struct rtnl_link *link, struct nl_msg *msg, void *data)
123 {
124 struct inet_data *id = data;
125 struct nlattr *nla;
126 int i;
127
128 if (!(nla = nla_nest_start(msg, IFLA_INET_CONF)))
129 return -NLE_MSGSIZE;
130
131 for (i = 0; i < IPV4_DEVCONF_MAX; i++)
132 if (id->i_confset[i])
133 NLA_PUT_U32(msg, i+1, id->i_conf[i]);
134
135 nla_nest_end(msg, nla);
136
137 return 0;
138
139 nla_put_failure:
140 return -NLE_MSGSIZE;
141 }
142
143 static const struct trans_tbl inet_devconf[] = {
144 __ADD(IPV4_DEVCONF_FORWARDING, forwarding)
145 __ADD(IPV4_DEVCONF_MC_FORWARDING, mc_forwarding)
146 __ADD(IPV4_DEVCONF_PROXY_ARP, proxy_arp)
147 __ADD(IPV4_DEVCONF_ACCEPT_REDIRECTS, accept_redirects)
148 __ADD(IPV4_DEVCONF_SECURE_REDIRECTS, secure_redirects)
149 __ADD(IPV4_DEVCONF_SEND_REDIRECTS, send_redirects)
150 __ADD(IPV4_DEVCONF_SHARED_MEDIA, shared_media)
151 __ADD(IPV4_DEVCONF_RP_FILTER, rp_filter)
152 __ADD(IPV4_DEVCONF_ACCEPT_SOURCE_ROUTE, accept_source_route)
153 __ADD(IPV4_DEVCONF_BOOTP_RELAY, bootp_relay)
154 __ADD(IPV4_DEVCONF_LOG_MARTIANS, log_martians)
155 __ADD(IPV4_DEVCONF_TAG, tag)
156 __ADD(IPV4_DEVCONF_ARPFILTER, arpfilter)
157 __ADD(IPV4_DEVCONF_MEDIUM_ID, medium_id)
158 __ADD(IPV4_DEVCONF_NOXFRM, noxfrm)
159 __ADD(IPV4_DEVCONF_NOPOLICY, nopolicy)
160 __ADD(IPV4_DEVCONF_FORCE_IGMP_VERSION, force_igmp_version)
161 __ADD(IPV4_DEVCONF_ARP_ANNOUNCE, arp_announce)
162 __ADD(IPV4_DEVCONF_ARP_IGNORE, arp_ignore)
163 __ADD(IPV4_DEVCONF_PROMOTE_SECONDARIES, promote_secondaries)
164 __ADD(IPV4_DEVCONF_ARP_ACCEPT, arp_accept)
165 __ADD(IPV4_DEVCONF_ARP_NOTIFY, arp_notify)
166 __ADD(IPV4_DEVCONF_ACCEPT_LOCAL, accept_local)
167 __ADD(IPV4_DEVCONF_SRC_VMARK, src_vmark)
168 __ADD(IPV4_DEVCONF_PROXY_ARP_PVLAN, proxy_arp_pvlan)
169 __ADD(IPV4_DEVCONF_ROUTE_LOCALNET, route_localnet)
170 __ADD(IPV4_DEVCONF_IGMPV2_UNSOLICITED_REPORT_INTERVAL, igmpv2_unsolicited_report_interval)
171 __ADD(IPV4_DEVCONF_IGMPV3_UNSOLICITED_REPORT_INTERVAL, igmpv3_unsolicited_report_interval)
172 };
173
rtnl_link_inet_devconf2str(int type,char * buf,size_t len)174 const char *rtnl_link_inet_devconf2str(int type, char *buf, size_t len)
175 {
176 return __type2str(type, buf, len, inet_devconf,
177 ARRAY_SIZE(inet_devconf));
178 }
179
rtnl_link_inet_str2devconf(const char * name)180 int rtnl_link_inet_str2devconf(const char *name)
181 {
182 return __str2type(name, inet_devconf, ARRAY_SIZE(inet_devconf));
183 }
184
inet_dump_details(struct rtnl_link * link,struct nl_dump_params * p,void * data)185 static void inet_dump_details(struct rtnl_link *link,
186 struct nl_dump_params *p, void *data)
187 {
188 struct inet_data *id = data;
189 char buf[64];
190 int i, n = 0;
191
192 nl_dump_line(p, " ipv4 devconf:\n");
193 nl_dump_line(p, " ");
194
195 for (i = 0; i < IPV4_DEVCONF_MAX; i++) {
196 nl_dump_line(p, "%-19s %3u",
197 rtnl_link_inet_devconf2str(i+1, buf, sizeof(buf)),
198 id->i_confset[i] ? id->i_conf[i] : 0);
199
200 if (++n == 3) {
201 nl_dump(p, "\n");
202 nl_dump_line(p, " ");
203 n = 0;
204 } else
205 nl_dump(p, " ");
206 }
207
208 if (n != 0)
209 nl_dump(p, "\n");
210 }
211
212 static struct rtnl_link_af_ops inet_ops = {
213 .ao_family = AF_INET,
214 .ao_alloc = &inet_alloc,
215 .ao_clone = &inet_clone,
216 .ao_free = &inet_free,
217 .ao_parse_af = &inet_parse_af,
218 .ao_fill_af = &inet_fill_af,
219 .ao_dump[NL_DUMP_DETAILS] = &inet_dump_details,
220 };
221
222 /**
223 * Get value of a ipv4 link configuration setting
224 * @arg link Link object
225 * @arg cfgid Configuration identifier
226 * @arg res Result pointer
227 *
228 * Stores the value of the specified configuration setting in the provided
229 * result pointer.
230 *
231 * @return 0 on success or a negative error code.
232 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
233 * @return -NLE_NOATTR configuration setting not available
234 * @return -NLE_INVAL cfgid not set. If the link was received via netlink,
235 * it means that the cfgid is not supported.
236 */
rtnl_link_inet_get_conf(struct rtnl_link * link,const unsigned int cfgid,uint32_t * res)237 int rtnl_link_inet_get_conf(struct rtnl_link *link, const unsigned int cfgid,
238 uint32_t *res)
239 {
240 struct inet_data *id;
241
242 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
243 return -NLE_RANGE;
244
245 if (!(id = rtnl_link_af_alloc(link, &inet_ops)))
246 return -NLE_NOATTR;
247
248 if (!id->i_confset[cfgid - 1])
249 return -NLE_INVAL;
250 *res = id->i_conf[cfgid - 1];
251
252 return 0;
253 }
254
255 /**
256 * Change value of a ipv4 link configuration setting
257 * @arg link Link object
258 * @arg cfgid Configuration identifier
259 * @arg value New value
260 *
261 * Changes the value in the per link ipv4 configuration array.
262 *
263 * @return 0 on success or a negative error code.
264 * @return -NLE_RANGE cfgid is out of range, 1..IPV4_DEVCONF_MAX
265 * @return -NLE_NOMEM memory allocation failed
266 */
rtnl_link_inet_set_conf(struct rtnl_link * link,const unsigned int cfgid,uint32_t value)267 int rtnl_link_inet_set_conf(struct rtnl_link *link, const unsigned int cfgid,
268 uint32_t value)
269 {
270 struct inet_data *id;
271
272 if (!(id = rtnl_link_af_alloc(link, &inet_ops)))
273 return -NLE_NOMEM;
274
275 if (cfgid == 0 || cfgid > IPV4_DEVCONF_MAX)
276 return -NLE_RANGE;
277
278 id->i_confset[cfgid - 1] = 1;
279 id->i_conf[cfgid - 1] = value;
280
281 return 0;
282 }
283
284
inet_init(void)285 static void __init inet_init(void)
286 {
287 rtnl_link_af_register(&inet_ops);
288 }
289
inet_exit(void)290 static void __exit inet_exit(void)
291 {
292 rtnl_link_af_unregister(&inet_ops);
293 }
294
295 /** @} */
296