From 716ca530e1c4515d8683c9d5be3d56b301758b66 Mon Sep 17 00:00:00 2001 From: James <> Date: Wed, 4 Nov 2015 11:49:21 +0000 Subject: trunk-47381 --- .../libnl-tiny/src/include/netlink/cache-api.h | 199 +++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 package/libs/libnl-tiny/src/include/netlink/cache-api.h (limited to 'package/libs/libnl-tiny/src/include/netlink/cache-api.h') diff --git a/package/libs/libnl-tiny/src/include/netlink/cache-api.h b/package/libs/libnl-tiny/src/include/netlink/cache-api.h new file mode 100644 index 0000000..22fc449 --- /dev/null +++ b/package/libs/libnl-tiny/src/include/netlink/cache-api.h @@ -0,0 +1,199 @@ +/* + * netlink/cache-api.h Caching API + * + * 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) 2003-2006 Thomas Graf + */ + +#ifndef NETLINK_CACHE_API_H_ +#define NETLINK_CACHE_API_H_ + +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @ingroup cache + * @defgroup cache_api Cache Implementation + * @brief + * + * @par 1) Cache Definition + * @code + * struct nl_cache_ops my_cache_ops = { + * .co_name = "route/link", + * .co_protocol = NETLINK_ROUTE, + * .co_hdrsize = sizeof(struct ifinfomsg), + * .co_obj_ops = &my_obj_ops, + * }; + * @endcode + * + * @par 2) + * @code + * // The simplest way to fill a cache is by providing a request-update + * // function which must trigger a complete dump on the kernel-side of + * // whatever the cache covers. + * static int my_request_update(struct nl_cache *cache, + * struct nl_sock *socket) + * { + * // In this example, we request a full dump of the interface table + * return nl_rtgen_request(socket, RTM_GETLINK, AF_UNSPEC, NLM_F_DUMP); + * } + * + * // The resulting netlink messages sent back will be fed into a message + * // parser one at a time. The message parser has to extract all relevant + * // information from the message and create an object reflecting the + * // contents of the message and pass it on to the parser callback function + * // provide which will add the object to the cache. + * static int my_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who, + * struct nlmsghdr *nlh, struct nl_parser_param *pp) + * { + * struct my_obj *obj; + * + * obj = my_obj_alloc(); + * obj->ce_msgtype = nlh->nlmsg_type; + * + * // Parse the netlink message and continue creating the object. + * + * err = pp->pp_cb((struct nl_object *) obj, pp); + * if (err < 0) + * goto errout; + * } + * + * struct nl_cache_ops my_cache_ops = { + * ... + * .co_request_update = my_request_update, + * .co_msg_parser = my_msg_parser, + * }; + * @endcode + * + * @par 3) Notification based Updates + * @code + * // Caches can be kept up-to-date based on notifications if the kernel + * // sends out notifications whenever an object is added/removed/changed. + * // + * // It is trivial to support this, first a list of groups needs to be + * // defined which are required to join in order to receive all necessary + * // notifications. The groups are separated by address family to support + * // the common situation where a separate group is used for each address + * // family. If there is only one group, simply specify AF_UNSPEC. + * static struct nl_af_group addr_groups[] = { + * { AF_INET, RTNLGRP_IPV4_IFADDR }, + * { AF_INET6, RTNLGRP_IPV6_IFADDR }, + * { END_OF_GROUP_LIST }, + * }; + * + * // In order for the caching system to know the meaning of each message + * // type it requires a table which maps each supported message type to + * // a cache action, e.g. RTM_NEWADDR means address has been added or + * // updated, RTM_DELADDR means address has been removed. + * static struct nl_cache_ops rtnl_addr_ops = { + * ... + * .co_msgtypes = { + * { RTM_NEWADDR, NL_ACT_NEW, "new" }, + * { RTM_DELADDR, NL_ACT_DEL, "del" }, + * { RTM_GETADDR, NL_ACT_GET, "get" }, + * END_OF_MSGTYPES_LIST, + * }, + * .co_groups = addr_groups, + * }; + * + * // It is now possible to keep the cache up-to-date using the cache manager. + * @endcode + * @{ + */ + +enum { + NL_ACT_UNSPEC, + NL_ACT_NEW, + NL_ACT_DEL, + NL_ACT_GET, + NL_ACT_SET, + NL_ACT_CHANGE, + __NL_ACT_MAX, +}; + +#define NL_ACT_MAX (__NL_ACT_MAX - 1) + +#define END_OF_MSGTYPES_LIST { -1, -1, NULL } + +/** + * Message type to cache action association + */ +struct nl_msgtype +{ + /** Netlink message type */ + int mt_id; + + /** Cache action to take */ + int mt_act; + + /** Name of operation for human-readable printing */ + char * mt_name; +}; + +/** + * Address family to netlink group association + */ +struct nl_af_group +{ + /** Address family */ + int ag_family; + + /** Netlink group identifier */ + int ag_group; +}; + +#define END_OF_GROUP_LIST AF_UNSPEC, 0 + +struct nl_parser_param +{ + int (*pp_cb)(struct nl_object *, struct nl_parser_param *); + void * pp_arg; +}; + +/** + * Cache Operations + */ +struct nl_cache_ops +{ + char * co_name; + + int co_hdrsize; + int co_protocol; + struct nl_af_group * co_groups; + + /** + * Called whenever an update of the cache is required. Must send + * a request message to the kernel requesting a complete dump. + */ + int (*co_request_update)(struct nl_cache *, struct nl_sock *); + + /** + * Called whenever a message was received that needs to be parsed. + * Must parse the message and call the paser callback function + * (nl_parser_param) provided via the argument. + */ + int (*co_msg_parser)(struct nl_cache_ops *, struct sockaddr_nl *, + struct nlmsghdr *, struct nl_parser_param *); + + struct nl_object_ops * co_obj_ops; + + struct nl_cache_ops *co_next; + struct nl_cache *co_major_cache; + struct genl_ops * co_genl; + struct nl_msgtype co_msgtypes[]; +}; + +/** @} */ + +#ifdef __cplusplus +} +#endif + +#endif -- cgit v1.2.3