route.c

/* SPDX-License-Identifier: LGPL-2.1-only */
/*
 * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
 */
 
/**
 * @ingroup rtnl
 * @defgroup route Routing
 * @brief
 * @{
 */
 
#include <netlink-private/netlink.h>
#include <netlink-private/nl-auto.h>
#include <netlink/netlink.h>
#include <netlink/cache.h>
#include <netlink/utils.h>
#include <netlink/data.h>
#include <netlink/route/rtnl.h>
#include <netlink/route/route.h>
#include <netlink/route/link.h>
 
static struct nl_cache_ops rtnl_route_ops;
 
static int route_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
                            struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
        struct rtnl_route *route;
        int err;
 
        if ((err = rtnl_route_parse(nlh, &route)) < 0)
                return err;
 
        err = pp->pp_cb((struct nl_object *) route, pp);
 
        rtnl_route_put(route);
        return err;
}
 
static int route_request_update(struct nl_cache *c, struct nl_sock *h)
{
        struct rtmsg rhdr = {
                .rtm_family = c->c_iarg1,
        };
 
        if (c->c_iarg2 & ROUTE_CACHE_CONTENT)
                rhdr.rtm_flags |= RTM_F_CLONED;
 
        return nl_send_simple(h, RTM_GETROUTE, NLM_F_DUMP, &rhdr, sizeof(rhdr));
}
 
/**
 * @name Cache Management
 * @{
 */
 
/**
 * Build a route cache holding all routes currently configured in the kernel
 * @arg sk              Netlink socket.
 * @arg family          Address family of routes to cover or AF_UNSPEC
 * @arg flags           Flags
 * @arg result          Result pointer
 *
 * Allocates a new cache, initializes it properly and updates it to
 * contain all routes currently configured in the kernel.
 *
 * Valid flags:
 *   * ROUTE_CACHE_CONTENT - Cache will contain contents of routing cache
 *                           instead of actual routes.
 *
 * @note The caller is responsible for destroying and freeing the
 *       cache after using it.
 * @return 0 on success or a negative error code.
 */
int rtnl_route_alloc_cache(struct nl_sock *sk, int family, int flags,
                           struct nl_cache **result)
{
        struct nl_cache *cache;
        int err;
 
        if (!(cache = nl_cache_alloc(&rtnl_route_ops)))
                return -NLE_NOMEM;
 
        cache->c_iarg1 = family;
        cache->c_iarg2 = flags;
 
        if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
                free(cache);
                return err;
        }
 
        *result = cache;
        return 0;
}
 
/** @} */
 
/**
 * @name Route Addition
 * @{
 */
 
static int build_route_msg(struct rtnl_route *tmpl, int cmd, int flags,
                           struct nl_msg **result)
{
        struct nl_msg *msg;
        int err;
 
        if (!(msg = nlmsg_alloc_simple(cmd, flags)))
                return -NLE_NOMEM;
 
        if ((err = rtnl_route_build_msg(msg, tmpl)) < 0) {
                nlmsg_free(msg);
                return err;
        }
 
        *result = msg;
        return 0;
}
 
int rtnl_route_build_add_request(struct rtnl_route *tmpl, int flags,
                                 struct nl_msg **result)
{
        return build_route_msg(tmpl, RTM_NEWROUTE, NLM_F_CREATE | flags,
                               result);
}
 
int rtnl_route_lookup(struct nl_sock *sk, struct nl_addr *dst,
                      struct rtnl_route **result)
{
        _nl_auto_nl_msg struct nl_msg *msg = NULL;
        _nl_auto_rtnl_route struct rtnl_route *tmpl = NULL;
        struct nl_object *obj;
        int err;
 
        tmpl = rtnl_route_alloc();
        rtnl_route_set_dst(tmpl, dst);
        err = build_route_msg(tmpl, RTM_GETROUTE, 0, &msg);
        if (err < 0)
                return err;
 
        err = nl_send_auto(sk, msg);
        if (err < 0)
                return err;
 
        if ((err = nl_pickup(sk, route_msg_parser, &obj)) < 0)
                return err;
 
        *result = (struct rtnl_route *)obj;
        wait_for_ack(sk);
        return 0;
}
 
int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
{
        struct nl_msg *msg;
        int err;
 
        if ((err = rtnl_route_build_add_request(route, flags, &msg)) < 0)
                return err;
 
        err = nl_send_auto_complete(sk, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return wait_for_ack(sk);
}
 
int rtnl_route_build_del_request(struct rtnl_route *tmpl, int flags,
                                 struct nl_msg **result)
{
        return build_route_msg(tmpl, RTM_DELROUTE, flags, result);
}
 
int rtnl_route_delete(struct nl_sock *sk, struct rtnl_route *route, int flags)
{
        struct nl_msg *msg;
        int err;
 
        if ((err = rtnl_route_build_del_request(route, flags, &msg)) < 0)
                return err;
 
        err = nl_send_auto_complete(sk, msg);
        nlmsg_free(msg);
        if (err < 0)
                return err;
 
        return wait_for_ack(sk);
}
 
/** @} */
 
static struct nl_af_group route_groups[] = {
        { AF_INET,      RTNLGRP_IPV4_ROUTE },
        { AF_INET6,     RTNLGRP_IPV6_ROUTE },
        { AF_MPLS,      RTNLGRP_MPLS_ROUTE },
        { AF_DECnet,    RTNLGRP_DECnet_ROUTE },
        { END_OF_GROUP_LIST },
};
 
static struct nl_cache_ops rtnl_route_ops = {
        .co_name                = "route/route",
        .co_hdrsize             = sizeof(struct rtmsg),
        .co_msgtypes            = {
                                        { RTM_NEWROUTE, NL_ACT_NEW, "new" },
                                        { RTM_DELROUTE, NL_ACT_DEL, "del" },
                                        { RTM_GETROUTE, NL_ACT_GET, "get" },
                                        END_OF_MSGTYPES_LIST,
                                  },
        .co_protocol            = NETLINK_ROUTE,
        .co_groups              = route_groups,
        .co_request_update      = route_request_update,
        .co_msg_parser          = route_msg_parser,
        .co_obj_ops             = &route_obj_ops,
};
 
static void __init route_init(void)
{
        nl_cache_mngt_register(&rtnl_route_ops);
}
 
static void __exit route_exit(void)
{
        nl_cache_mngt_unregister(&rtnl_route_ops);
}
 
/** @} */