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/*
* lib/genl/mngt.c Generic Netlink Management
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
*/
/**
* @ingroup genl
* @defgroup genl_mngt Management
*
* @par 1) Registering a generic netlink module
* @code
* #include <netlink/genl/mngt.h>
*
* // First step is to define all the commands being used in
* // particular generic netlink family. The ID and name are
* // mandatory to be filled out. A callback function and
* // most the attribute policy that comes with it must be
* // defined for commands expected to be issued towards
* // userspace.
* static struct genl_cmd foo_cmds[] = {
* {
* .c_id = FOO_CMD_NEW,
* .c_name = "NEWFOO" ,
* .c_maxattr = FOO_ATTR_MAX,
* .c_attr_policy = foo_policy,
* .c_msg_parser = foo_msg_parser,
* },
* {
* .c_id = FOO_CMD_DEL,
* .c_name = "DELFOO" ,
* },
* };
*
* // The list of commands must then be integrated into a
* // struct genl_ops serving as handle for this particular
* // family.
* static struct genl_ops my_genl_ops = {
* .o_cmds = foo_cmds,
* .o_ncmds = ARRAY_SIZE(foo_cmds),
* };
*
* // Using the above struct genl_ops an arbitary number of
* // cache handles can be associated to it.
* //
* // The macro GENL_HDRSIZE() must be used to specify the
* // length of the header to automatically take headers on
* // generic layers into account.
* //
* // The macro GENL_FAMILY() is used to represent the generic
* // netlink family id.
* static struct nl_cache_ops genl_foo_ops = {
* .co_name = "genl/foo",
* .co_hdrsize = GENL_HDRSIZE(sizeof(struct my_hdr)),
* .co_msgtypes = GENL_FAMILY(GENL_ID_GENERATE, "foo"),
* .co_genl = &my_genl_ops,
* .co_protocol = NETLINK_GENERIC,
* .co_request_update = foo_request_update,
* .co_obj_ops = &genl_foo_ops,
* };
*
* // Finally each cache handle for a generic netlink family
* // must be registered using genl_register().
* static void __init foo_init(void)
* {
* genl_register(&genl_foo_ops);
* }
*
* // ... respectively unregsted again.
* static void __exit foo_exit(void)
* {
* genl_unregister(&genl_foo_ops);
* }
* @endcode
* @{
*/
#include <netlink-generic.h>
#include <netlink/netlink.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/mngt.h>
#include <netlink/genl/family.h>
#include <netlink/genl/ctrl.h>
#include <netlink/utils.h>
static NL_LIST_HEAD(genl_ops_list);
static int genl_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
int i, err;
struct genlmsghdr *ghdr;
struct genl_cmd *cmd;
ghdr = nlmsg_data(nlh);
if (ops->co_genl == NULL)
BUG();
for (i = 0; i < ops->co_genl->o_ncmds; i++) {
cmd = &ops->co_genl->o_cmds[i];
if (cmd->c_id == ghdr->cmd)
goto found;
}
err = -NLE_MSGTYPE_NOSUPPORT;
goto errout;
found:
if (cmd->c_msg_parser == NULL)
err = -NLE_OPNOTSUPP;
else {
struct nlattr *tb[cmd->c_maxattr + 1];
struct genl_info info = {
.who = who,
.nlh = nlh,
.genlhdr = ghdr,
.userhdr = genlmsg_data(ghdr),
.attrs = tb,
};
err = nlmsg_parse(nlh, ops->co_hdrsize, tb, cmd->c_maxattr,
cmd->c_attr_policy);
if (err < 0)
goto errout;
err = cmd->c_msg_parser(ops, cmd, &info, pp);
}
errout:
return err;
}
/**
* @name Register/Unregister
* @{
*/
/**
* Register generic netlink operations
* @arg ops cache operations
*/
int genl_register(struct nl_cache_ops *ops)
{
int err;
if (ops->co_protocol != NETLINK_GENERIC) {
err = -NLE_PROTO_MISMATCH;
goto errout;
}
if ((size_t) ops->co_hdrsize < GENL_HDRSIZE(0)) {
err = -NLE_INVAL;
goto errout;
}
if (ops->co_genl == NULL) {
err = -NLE_INVAL;
goto errout;
}
ops->co_genl->o_cache_ops = ops;
ops->co_genl->o_name = ops->co_msgtypes[0].mt_name;
ops->co_genl->o_family = ops->co_msgtypes[0].mt_id;
ops->co_msg_parser = genl_msg_parser;
/* FIXME: check for dup */
nl_list_add_tail(&ops->co_genl->o_list, &genl_ops_list);
err = nl_cache_mngt_register(ops);
errout:
return err;
}
/**
* Unregister generic netlink operations
* @arg ops cache operations
*/
void genl_unregister(struct nl_cache_ops *ops)
{
nl_cache_mngt_unregister(ops);
nl_list_del(&ops->co_genl->o_list);
}
/** @} */
/** @} */
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