Root/package/libnl-tiny/src/genl_ctrl.c

1/*
2 * lib/genl/ctrl.c Generic Netlink Controller
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 genl_mngt
14 * @defgroup ctrl Controller
15 * @brief
16 *
17 * @{
18 */
19
20#include <netlink-generic.h>
21#include <netlink/netlink.h>
22#include <netlink/genl/genl.h>
23#include <netlink/genl/family.h>
24#include <netlink/genl/mngt.h>
25#include <netlink/genl/ctrl.h>
26#include <netlink/utils.h>
27
28/** @cond SKIP */
29#define CTRL_VERSION 0x0001
30
31static struct nl_cache_ops genl_ctrl_ops;
32/** @endcond */
33
34static int ctrl_request_update(struct nl_cache *c, struct nl_sock *h)
35{
36    return genl_send_simple(h, GENL_ID_CTRL, CTRL_CMD_GETFAMILY,
37                CTRL_VERSION, NLM_F_DUMP);
38}
39
40static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
41    [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
42    [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING,
43                    .maxlen = GENL_NAMSIZ },
44    [CTRL_ATTR_VERSION] = { .type = NLA_U32 },
45    [CTRL_ATTR_HDRSIZE] = { .type = NLA_U32 },
46    [CTRL_ATTR_MAXATTR] = { .type = NLA_U32 },
47    [CTRL_ATTR_OPS] = { .type = NLA_NESTED },
48};
49
50static struct nla_policy family_op_policy[CTRL_ATTR_OP_MAX+1] = {
51    [CTRL_ATTR_OP_ID] = { .type = NLA_U32 },
52    [CTRL_ATTR_OP_FLAGS] = { .type = NLA_U32 },
53};
54
55static int ctrl_msg_parser(struct nl_cache_ops *ops, struct genl_cmd *cmd,
56               struct genl_info *info, void *arg)
57{
58    struct genl_family *family;
59    struct nl_parser_param *pp = arg;
60    int err;
61
62    family = genl_family_alloc();
63    if (family == NULL) {
64        err = -NLE_NOMEM;
65        goto errout;
66    }
67
68    if (info->attrs[CTRL_ATTR_FAMILY_NAME] == NULL) {
69        err = -NLE_MISSING_ATTR;
70        goto errout;
71    }
72
73    if (info->attrs[CTRL_ATTR_FAMILY_ID] == NULL) {
74        err = -NLE_MISSING_ATTR;
75        goto errout;
76    }
77
78    family->ce_msgtype = info->nlh->nlmsg_type;
79    genl_family_set_id(family,
80               nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]));
81    genl_family_set_name(family,
82             nla_get_string(info->attrs[CTRL_ATTR_FAMILY_NAME]));
83
84    if (info->attrs[CTRL_ATTR_VERSION]) {
85        uint32_t version = nla_get_u32(info->attrs[CTRL_ATTR_VERSION]);
86        genl_family_set_version(family, version);
87    }
88
89    if (info->attrs[CTRL_ATTR_HDRSIZE]) {
90        uint32_t hdrsize = nla_get_u32(info->attrs[CTRL_ATTR_HDRSIZE]);
91        genl_family_set_hdrsize(family, hdrsize);
92    }
93
94    if (info->attrs[CTRL_ATTR_MAXATTR]) {
95        uint32_t maxattr = nla_get_u32(info->attrs[CTRL_ATTR_MAXATTR]);
96        genl_family_set_maxattr(family, maxattr);
97    }
98
99    if (info->attrs[CTRL_ATTR_OPS]) {
100        struct nlattr *nla, *nla_ops;
101        int remaining;
102
103        nla_ops = info->attrs[CTRL_ATTR_OPS];
104        nla_for_each_nested(nla, nla_ops, remaining) {
105            struct nlattr *tb[CTRL_ATTR_OP_MAX+1];
106            int flags = 0, id;
107
108            err = nla_parse_nested(tb, CTRL_ATTR_OP_MAX, nla,
109                           family_op_policy);
110            if (err < 0)
111                goto errout;
112
113            if (tb[CTRL_ATTR_OP_ID] == NULL) {
114                err = -NLE_MISSING_ATTR;
115                goto errout;
116            }
117            
118            id = nla_get_u32(tb[CTRL_ATTR_OP_ID]);
119
120            if (tb[CTRL_ATTR_OP_FLAGS])
121                flags = nla_get_u32(tb[CTRL_ATTR_OP_FLAGS]);
122
123            err = genl_family_add_op(family, id, flags);
124            if (err < 0)
125                goto errout;
126
127        }
128    }
129
130    err = pp->pp_cb((struct nl_object *) family, pp);
131errout:
132    genl_family_put(family);
133    return err;
134}
135
136/**
137 * @name Cache Management
138 * @{
139 */
140
141int genl_ctrl_alloc_cache(struct nl_sock *sock, struct nl_cache **result)
142{
143    return nl_cache_alloc_and_fill(&genl_ctrl_ops, sock, result);
144}
145
146/**
147 * Look up generic netlink family by id in the provided cache.
148 * @arg cache Generic netlink family cache.
149 * @arg id Family identifier.
150 *
151 * Searches through the cache looking for a registered family
152 * matching the specified identifier. The caller will own a
153 * reference on the returned object which needs to be given
154 * back after usage using genl_family_put().
155 *
156 * @return Generic netlink family object or NULL if no match was found.
157 */
158struct genl_family *genl_ctrl_search(struct nl_cache *cache, int id)
159{
160    struct genl_family *fam;
161
162    if (cache->c_ops != &genl_ctrl_ops)
163        BUG();
164
165    nl_list_for_each_entry(fam, &cache->c_items, ce_list) {
166        if (fam->gf_id == id) {
167            nl_object_get((struct nl_object *) fam);
168            return fam;
169        }
170    }
171
172    return NULL;
173}
174
175/**
176 * @name Resolver
177 * @{
178 */
179
180/**
181 * Look up generic netlink family by family name in the provided cache.
182 * @arg cache Generic netlink family cache.
183 * @arg name Family name.
184 *
185 * Searches through the cache looking for a registered family
186 * matching the specified name. The caller will own a reference
187 * on the returned object which needs to be given back after
188 * usage using genl_family_put().
189 *
190 * @return Generic netlink family object or NULL if no match was found.
191 */
192struct genl_family *genl_ctrl_search_by_name(struct nl_cache *cache,
193                        const char *name)
194{
195    struct genl_family *fam;
196
197    if (cache->c_ops != &genl_ctrl_ops)
198        BUG();
199
200    nl_list_for_each_entry(fam, &cache->c_items, ce_list) {
201        if (!strcmp(name, fam->gf_name)) {
202            nl_object_get((struct nl_object *) fam);
203            return fam;
204        }
205    }
206
207    return NULL;
208}
209
210/** @} */
211
212/**
213 * Resolve generic netlink family name to its identifier
214 * @arg sk Netlink socket.
215 * @arg name Name of generic netlink family
216 *
217 * Resolves the generic netlink family name to its identifer and returns
218 * it.
219 *
220 * @return A positive identifier or a negative error code.
221 */
222int genl_ctrl_resolve(struct nl_sock *sk, const char *name)
223{
224    struct nl_cache *cache;
225    struct genl_family *family;
226    int err;
227
228    if ((err = genl_ctrl_alloc_cache(sk, &cache)) < 0)
229        return err;
230
231    family = genl_ctrl_search_by_name(cache, name);
232    if (family == NULL) {
233        err = -NLE_OBJ_NOTFOUND;
234        goto errout;
235    }
236
237    err = genl_family_get_id(family);
238    genl_family_put(family);
239errout:
240    nl_cache_free(cache);
241
242    return err;
243}
244
245/** @} */
246
247static struct genl_cmd genl_cmds[] = {
248    {
249        .c_id = CTRL_CMD_NEWFAMILY,
250        .c_name = "NEWFAMILY" ,
251        .c_maxattr = CTRL_ATTR_MAX,
252        .c_attr_policy = ctrl_policy,
253        .c_msg_parser = ctrl_msg_parser,
254    },
255    {
256        .c_id = CTRL_CMD_DELFAMILY,
257        .c_name = "DELFAMILY" ,
258    },
259    {
260        .c_id = CTRL_CMD_GETFAMILY,
261        .c_name = "GETFAMILY" ,
262    },
263    {
264        .c_id = CTRL_CMD_NEWOPS,
265        .c_name = "NEWOPS" ,
266    },
267    {
268        .c_id = CTRL_CMD_DELOPS,
269        .c_name = "DELOPS" ,
270    },
271};
272
273static struct genl_ops genl_ops = {
274    .o_cmds = genl_cmds,
275    .o_ncmds = ARRAY_SIZE(genl_cmds),
276};
277
278/** @cond SKIP */
279extern struct nl_object_ops genl_family_ops;
280/** @endcond */
281
282static struct nl_cache_ops genl_ctrl_ops = {
283    .co_name = "genl/family",
284    .co_hdrsize = GENL_HDRSIZE(0),
285    .co_msgtypes = GENL_FAMILY(GENL_ID_CTRL, "nlctrl"),
286    .co_genl = &genl_ops,
287    .co_protocol = NETLINK_GENERIC,
288    .co_request_update = ctrl_request_update,
289    .co_obj_ops = &genl_family_ops,
290};
291
292static void __init ctrl_init(void)
293{
294    genl_register(&genl_ctrl_ops);
295}
296
297static void __exit ctrl_exit(void)
298{
299    genl_unregister(&genl_ctrl_ops);
300}
301
302/** @} */
303

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