2 * lib/genl/mngt.c Generic Netlink Management
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
9 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
14 * @defgroup genl_mngt Management
16 * @par 1) Registering a generic netlink module
18 * #include <netlink/genl/mngt.h>
20 * // First step is to define all the commands being used in
21 * // particular generic netlink family. The ID and name are
22 * // mandatory to be filled out. A callback function and
23 * // most the attribute policy that comes with it must be
24 * // defined for commands expected to be issued towards
26 * static struct genl_cmd foo_cmds[] = {
28 * .c_id = FOO_CMD_NEW,
29 * .c_name = "NEWFOO" ,
30 * .c_maxattr = FOO_ATTR_MAX,
31 * .c_attr_policy = foo_policy,
32 * .c_msg_parser = foo_msg_parser,
35 * .c_id = FOO_CMD_DEL,
36 * .c_name = "DELFOO" ,
40 * // The list of commands must then be integrated into a
41 * // struct genl_ops serving as handle for this particular
43 * static struct genl_ops my_genl_ops = {
45 * .o_ncmds = ARRAY_SIZE(foo_cmds),
48 * // Using the above struct genl_ops an arbitary number of
49 * // cache handles can be associated to it.
51 * // The macro GENL_HDRSIZE() must be used to specify the
52 * // length of the header to automatically take headers on
53 * // generic layers into account.
55 * // The macro GENL_FAMILY() is used to represent the generic
56 * // netlink family id.
57 * static struct nl_cache_ops genl_foo_ops = {
58 * .co_name = "genl/foo",
59 * .co_hdrsize = GENL_HDRSIZE(sizeof(struct my_hdr)),
60 * .co_msgtypes = GENL_FAMILY(GENL_ID_GENERATE, "foo"),
61 * .co_genl = &my_genl_ops,
62 * .co_protocol = NETLINK_GENERIC,
63 * .co_request_update = foo_request_update,
64 * .co_obj_ops = &genl_foo_ops,
67 * // Finally each cache handle for a generic netlink family
68 * // must be registered using genl_register().
69 * static void __init foo_init(void)
71 * genl_register(&genl_foo_ops);
74 * // ... respectively unregsted again.
75 * static void __exit foo_exit(void)
77 * genl_unregister(&genl_foo_ops);
83 #include <netlink-generic.h>
84 #include <netlink/netlink.h>
85 #include <netlink/genl/genl.h>
86 #include <netlink/genl/mngt.h>
87 #include <netlink/genl/family.h>
88 #include <netlink/genl/ctrl.h>
89 #include <netlink/utils.h>
91 static NL_LIST_HEAD(genl_ops_list);
93 static int genl_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
94 struct nlmsghdr *nlh, struct nl_parser_param *pp)
97 struct genlmsghdr *ghdr;
100 ghdr = nlmsg_data(nlh);
102 if (ops->co_genl == NULL)
105 for (i = 0; i < ops->co_genl->o_ncmds; i++) {
106 cmd = &ops->co_genl->o_cmds[i];
107 if (cmd->c_id == ghdr->cmd)
111 err = -NLE_MSGTYPE_NOSUPPORT;
115 if (cmd->c_msg_parser == NULL)
116 err = -NLE_OPNOTSUPP;
118 struct nlattr *tb[cmd->c_maxattr + 1];
119 struct genl_info info = {
123 .userhdr = genlmsg_data(ghdr),
127 err = nlmsg_parse(nlh, ops->co_hdrsize, tb, cmd->c_maxattr,
132 err = cmd->c_msg_parser(ops, cmd, &info, pp);
139 char *genl_op2name(int family, int op, char *buf, size_t len)
141 struct genl_ops *ops;
144 nl_list_for_each_entry(ops, &genl_ops_list, o_list) {
145 if (ops->o_family == family) {
146 for (i = 0; i < ops->o_ncmds; i++) {
147 struct genl_cmd *cmd;
148 cmd = &ops->o_cmds[i];
150 if (cmd->c_id == op) {
151 strncpy(buf, cmd->c_name, len - 1);
158 strncpy(buf, "unknown", len - 1);
164 * @name Register/Unregister
169 * Register generic netlink operations
170 * @arg ops cache operations
172 int genl_register(struct nl_cache_ops *ops)
176 if (ops->co_protocol != NETLINK_GENERIC) {
177 err = -NLE_PROTO_MISMATCH;
181 if (ops->co_hdrsize < GENL_HDRSIZE(0)) {
186 if (ops->co_genl == NULL) {
191 ops->co_genl->o_cache_ops = ops;
192 ops->co_genl->o_name = ops->co_msgtypes[0].mt_name;
193 ops->co_genl->o_family = ops->co_msgtypes[0].mt_id;
194 ops->co_msg_parser = genl_msg_parser;
196 /* FIXME: check for dup */
198 nl_list_add_tail(&ops->co_genl->o_list, &genl_ops_list);
200 err = nl_cache_mngt_register(ops);
206 * Unregister generic netlink operations
207 * @arg ops cache operations
209 void genl_unregister(struct nl_cache_ops *ops)
211 nl_cache_mngt_unregister(ops);
212 nl_list_del(&ops->co_genl->o_list);
218 * @name Resolving ID/Name
222 static int __genl_ops_resolve(struct nl_cache *ctrl, struct genl_ops *ops)
224 struct genl_family *family;
226 family = genl_ctrl_search_by_name(ctrl, ops->o_name);
227 if (family != NULL) {
228 ops->o_id = genl_family_get_id(family);
229 genl_family_put(family);
234 return -NLE_OBJ_NOTFOUND;
237 int genl_ops_resolve(struct nl_sock *sk, struct genl_ops *ops)
239 struct nl_cache *ctrl;
242 if ((err = genl_ctrl_alloc_cache(sk, &ctrl)) < 0)
245 err = __genl_ops_resolve(ctrl, ops);
252 int genl_mngt_resolve(struct nl_sock *sk)
254 struct nl_cache *ctrl;
255 struct genl_ops *ops;
258 if ((err = genl_ctrl_alloc_cache(sk, &ctrl)) < 0)
261 nl_list_for_each_entry(ops, &genl_ops_list, o_list) {
262 err = __genl_ops_resolve(ctrl, ops);