forked from Minki/linux
4d8b931928
Add an initial neighbour table implementation, to be used in the route output path. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
142 lines
3.1 KiB
C
142 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Management Component Transport Protocol (MCTP) - routing
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* implementation.
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*
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* This is currently based on a simple routing table, with no dst cache. The
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* number of routes should stay fairly small, so the lookup cost is small.
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*
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* Copyright (c) 2021 Code Construct
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* Copyright (c) 2021 Google
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*/
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#include <linux/idr.h>
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#include <linux/mctp.h>
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#include <linux/netdevice.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <net/mctp.h>
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#include <net/mctpdevice.h>
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#include <net/netlink.h>
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#include <net/sock.h>
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static int __always_unused mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid,
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enum mctp_neigh_source source,
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size_t lladdr_len, const void *lladdr)
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{
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struct net *net = dev_net(mdev->dev);
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struct mctp_neigh *neigh;
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int rc;
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mutex_lock(&net->mctp.neigh_lock);
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if (mctp_neigh_lookup(mdev, eid, NULL) == 0) {
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rc = -EEXIST;
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goto out;
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}
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if (lladdr_len > sizeof(neigh->ha)) {
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rc = -EINVAL;
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goto out;
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}
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neigh = kzalloc(sizeof(*neigh), GFP_KERNEL);
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if (!neigh) {
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rc = -ENOMEM;
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goto out;
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}
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INIT_LIST_HEAD(&neigh->list);
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neigh->dev = mdev;
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dev_hold(neigh->dev->dev);
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neigh->eid = eid;
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neigh->source = source;
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memcpy(neigh->ha, lladdr, lladdr_len);
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list_add_rcu(&neigh->list, &net->mctp.neighbours);
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rc = 0;
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out:
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mutex_unlock(&net->mctp.neigh_lock);
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return rc;
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}
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static void __mctp_neigh_free(struct rcu_head *rcu)
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{
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struct mctp_neigh *neigh = container_of(rcu, struct mctp_neigh, rcu);
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dev_put(neigh->dev->dev);
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kfree(neigh);
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}
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/* Removes all neighbour entries referring to a device */
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void mctp_neigh_remove_dev(struct mctp_dev *mdev)
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{
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struct net *net = dev_net(mdev->dev);
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struct mctp_neigh *neigh, *tmp;
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mutex_lock(&net->mctp.neigh_lock);
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list_for_each_entry_safe(neigh, tmp, &net->mctp.neighbours, list) {
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if (neigh->dev == mdev) {
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list_del_rcu(&neigh->list);
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/* TODO: immediate RTM_DELNEIGH */
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call_rcu(&neigh->rcu, __mctp_neigh_free);
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}
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}
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mutex_unlock(&net->mctp.neigh_lock);
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}
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int mctp_neigh_lookup(struct mctp_dev *mdev, mctp_eid_t eid, void *ret_hwaddr)
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{
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struct net *net = dev_net(mdev->dev);
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struct mctp_neigh *neigh;
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int rc = -EHOSTUNREACH; // TODO: or ENOENT?
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rcu_read_lock();
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list_for_each_entry_rcu(neigh, &net->mctp.neighbours, list) {
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if (mdev == neigh->dev && eid == neigh->eid) {
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if (ret_hwaddr)
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memcpy(ret_hwaddr, neigh->ha,
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sizeof(neigh->ha));
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rc = 0;
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break;
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}
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}
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rcu_read_unlock();
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return rc;
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}
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/* namespace registration */
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static int __net_init mctp_neigh_net_init(struct net *net)
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{
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struct netns_mctp *ns = &net->mctp;
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INIT_LIST_HEAD(&ns->neighbours);
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return 0;
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}
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static void __net_exit mctp_neigh_net_exit(struct net *net)
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{
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struct netns_mctp *ns = &net->mctp;
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struct mctp_neigh *neigh;
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list_for_each_entry(neigh, &ns->neighbours, list)
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call_rcu(&neigh->rcu, __mctp_neigh_free);
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}
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/* net namespace implementation */
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static struct pernet_operations mctp_net_ops = {
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.init = mctp_neigh_net_init,
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.exit = mctp_neigh_net_exit,
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};
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int __init mctp_neigh_init(void)
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{
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return register_pernet_subsys(&mctp_net_ops);
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}
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void __exit mctp_neigh_exit(void)
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{
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unregister_pernet_subsys(&mctp_net_ops);
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}
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