mngt.h

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2012 Thomas Graf <tgraf@suug.ch>
 */
 
#ifndef NETLINK_GENL_MNGT_H_
#define NETLINK_GENL_MNGT_H_
 
#include <netlink/netlink.h>
#include <netlink/attr.h>
#include <netlink/list.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
struct nl_cache_ops;
 
/**
 * @ingroup genl_mngt
 * @struct genl_info netlink/genl/mngt.h
 *
 * Informative structure passed on to message parser callbacks
 *
 * This structure is passed on to all message parser callbacks and contains
 * information about the sender of the message as well as pointers to all
 * relevant sections of the parsed message.
 *
 * @see genl_cmd::c_msg_parser
 */
struct genl_info
{
        /** Socket address of sender */
        struct sockaddr_nl *    who;
 
        /** Pointer to Netlink message header */
        struct nlmsghdr *       nlh;
 
        /** Pointer to Generic Netlink message header */
        struct genlmsghdr *     genlhdr;
 
        /** Pointer to user header */
        void *                  userhdr;
 
        /** Pointer to array of parsed attributes */
        struct nlattr **        attrs;
};
 
/**
 * @ingroup genl_mngt
 * @struct genl_cmd netlink/genl/mngt.h
 *
 * Definition of a Generic Netlink command.
 *
 * This structure is used to define the list of available commands on the
 * receiving side.
 *
 * @par Example:
 * @code
 * 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" ,
 *      },
 * };
 *
 * static struct genl_ops my_genl_ops = {
 *      [...]
 *      .o_cmds                 = foo_cmds,
 *      .o_ncmds                = ARRAY_SIZE(foo_cmds),
 * };
 * @endcode
 */
struct genl_cmd
{
        /** Numeric command identifier (required) */
        int                     c_id;
 
        /** Human readable name  (required) */
        char *                  c_name;
 
        /** Maximum attribute identifier that the command is prepared to handle. */
        int                     c_maxattr;
 
        /** Called whenever a message for this command is received */
        int                   (*c_msg_parser)(struct nl_cache_ops *,
                                              struct genl_cmd *,
                                              struct genl_info *, void *);
 
        /** Attribute validation policy, enforced before the callback is called */
        struct nla_policy *     c_attr_policy;
};
 
/**
 * @ingroup genl_mngt
 * @struct genl_ops netlink/genl/mngt.h
 *
 * Definition of a Generic Netlink family
 *
 * @par Example:
 * @code
 * static struct genl_cmd foo_cmds[] = {
 *      [...]
 * };
 *
 * static struct genl_ops my_genl_ops = {
 *      .o_name                 = "foo",
 *      .o_hdrsize              = sizeof(struct my_hdr),
 *      .o_cmds                 = foo_cmds,
 *      .o_ncmds                = ARRAY_SIZE(foo_cmds),
 * };
 *
 * if ((err = genl_register_family(&my_genl_ops)) < 0)
 *      // ERROR
 * @endcode
 *
 * @see genl_cmd
 */
struct genl_ops
{
        /** Length of user header */
        unsigned int            o_hdrsize;
 
        /** Numeric identifier, automatically filled in by genl_ops_resolve() */
        int                     o_id;
 
        /** Human readable name, used by genl_ops_resolve() to resolve numeric id */
        char *                  o_name;
 
        /**
         * If registered via genl_register(), will point to the related
         * cache operations.
         */
        struct nl_cache_ops *   o_cache_ops;
 
        /** Optional array defining the available Generic Netlink commands */
        struct genl_cmd *       o_cmds;
 
        /** Number of elements in \c o_cmds array */
        int                     o_ncmds;
 
        /**
         * @private
         * Used internally to link together all registered operations.
         */
        struct nl_list_head     o_list;
};
 
extern int              genl_register_family(struct genl_ops *);
extern int              genl_unregister_family(struct genl_ops *);
extern int              genl_handle_msg(struct nl_msg *, void *);
 
extern int              genl_register(struct nl_cache_ops *);
extern void             genl_unregister(struct nl_cache_ops *);
 
extern int              genl_ops_resolve(struct nl_sock *, struct genl_ops *);
extern int              genl_mngt_resolve(struct nl_sock *);
 
#ifdef __cplusplus
}
#endif
 
#endif