Commit 831119f8 authored by Matt Johnston's avatar Matt Johnston Committed by David S. Miller
Browse files

mctp: Add neighbour netlink interface 



This change adds the netlink interfaces for manipulating the MCTP
neighbour table.

Signed-off-by: default avatarMatt Johnston <matt@codeconstruct.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4d8b9319

net/mctp/neigh.c

+204 −3
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
#include <net/netlink.h>

#include <net/sock.h>



static int __always_unused mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid,

static int mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid,

			  enum mctp_neigh_source source,

			  size_t lladdr_len, const void *lladdr)

{
@@ -85,6 +85,196 @@ void mctp_neigh_remove_dev(struct mctp_dev *mdev) 
	mutex_unlock(&net->mctp.neigh_lock);

}



// TODO: add a "source" flag so netlink can only delete static neighbours?

static int mctp_neigh_remove(struct mctp_dev *mdev, mctp_eid_t eid)

{

	struct net *net = dev_net(mdev->dev);

	struct mctp_neigh *neigh, *tmp;

	bool dropped = false;



	mutex_lock(&net->mctp.neigh_lock);

	list_for_each_entry_safe(neigh, tmp, &net->mctp.neighbours, list) {

		if (neigh->dev == mdev && neigh->eid == eid) {

			list_del_rcu(&neigh->list);

			/* TODO: immediate RTM_DELNEIGH */

			call_rcu(&neigh->rcu, __mctp_neigh_free);

			dropped = true;

		}

	}



	mutex_unlock(&net->mctp.neigh_lock);

	return dropped ? 0 : -ENOENT;

}



static const struct nla_policy nd_mctp_policy[NDA_MAX + 1] = {

	[NDA_DST]		= { .type = NLA_U8 },

	[NDA_LLADDR]		= { .type = NLA_BINARY, .len = MAX_ADDR_LEN },

};



static int mctp_rtm_newneigh(struct sk_buff *skb, struct nlmsghdr *nlh,

			     struct netlink_ext_ack *extack)

{

	struct net *net = sock_net(skb->sk);

	struct net_device *dev;

	struct mctp_dev *mdev;

	struct ndmsg *ndm;

	struct nlattr *tb[NDA_MAX + 1];

	int rc;

	mctp_eid_t eid;

	void *lladdr;

	int lladdr_len;



	rc = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, nd_mctp_policy,

			 extack);

	if (rc < 0) {

		NL_SET_ERR_MSG(extack, "lladdr too large?");

		return rc;

	}



	if (!tb[NDA_DST]) {

		NL_SET_ERR_MSG(extack, "Neighbour EID must be specified");

		return -EINVAL;

	}



	if (!tb[NDA_LLADDR]) {

		NL_SET_ERR_MSG(extack, "Neighbour lladdr must be specified");

		return -EINVAL;

	}



	eid = nla_get_u8(tb[NDA_DST]);

	if (!mctp_address_ok(eid)) {

		NL_SET_ERR_MSG(extack, "Invalid neighbour EID");

		return -EINVAL;

	}



	lladdr = nla_data(tb[NDA_LLADDR]);

	lladdr_len = nla_len(tb[NDA_LLADDR]);



	ndm = nlmsg_data(nlh);



	dev = __dev_get_by_index(net, ndm->ndm_ifindex);

	if (!dev)

		return -ENODEV;



	mdev = mctp_dev_get_rtnl(dev);

	if (!mdev)

		return -ENODEV;



	if (lladdr_len != dev->addr_len) {

		NL_SET_ERR_MSG(extack, "Wrong lladdr length");

		return -EINVAL;

	}



	return mctp_neigh_add(mdev, eid, MCTP_NEIGH_STATIC,

			lladdr_len, lladdr);

}



static int mctp_rtm_delneigh(struct sk_buff *skb, struct nlmsghdr *nlh,

			     struct netlink_ext_ack *extack)

{

	struct net *net = sock_net(skb->sk);

	struct nlattr *tb[NDA_MAX + 1];

	struct net_device *dev;

	struct mctp_dev *mdev;

	struct ndmsg *ndm;

	int rc;

	mctp_eid_t eid;



	rc = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, nd_mctp_policy,

			 extack);

	if (rc < 0) {

		NL_SET_ERR_MSG(extack, "incorrect format");

		return rc;

	}



	if (!tb[NDA_DST]) {

		NL_SET_ERR_MSG(extack, "Neighbour EID must be specified");

		return -EINVAL;

	}

	eid = nla_get_u8(tb[NDA_DST]);



	ndm = nlmsg_data(nlh);

	dev = __dev_get_by_index(net, ndm->ndm_ifindex);

	if (!dev)

		return -ENODEV;



	mdev = mctp_dev_get_rtnl(dev);

	if (!mdev)

		return -ENODEV;



	return mctp_neigh_remove(mdev, eid);

}



static int mctp_fill_neigh(struct sk_buff *skb, u32 portid, u32 seq, int event,

			   unsigned int flags, struct mctp_neigh *neigh)

{

	struct net_device *dev = neigh->dev->dev;

	struct nlmsghdr *nlh;

	struct ndmsg *hdr;



	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);

	if (!nlh)

		return -EMSGSIZE;



	hdr = nlmsg_data(nlh);

	hdr->ndm_family = AF_MCTP;

	hdr->ndm_ifindex = dev->ifindex;

	hdr->ndm_state = 0; // TODO other state bits?

	if (neigh->source == MCTP_NEIGH_STATIC)

		hdr->ndm_state |= NUD_PERMANENT;

	hdr->ndm_flags = 0;

	hdr->ndm_type = RTN_UNICAST; // TODO: is loopback RTN_LOCAL?



	if (nla_put_u8(skb, NDA_DST, neigh->eid))

		goto cancel;



	if (nla_put(skb, NDA_LLADDR, dev->addr_len, neigh->ha))

		goto cancel;



	nlmsg_end(skb, nlh);



	return 0;

cancel:

	nlmsg_cancel(skb, nlh);

	return -EMSGSIZE;

}



static int mctp_rtm_getneigh(struct sk_buff *skb, struct netlink_callback *cb)

{

	struct net *net = sock_net(skb->sk);

	int rc, idx, req_ifindex;

	struct mctp_neigh *neigh;

	struct ndmsg *ndmsg;

	struct {

		int idx;

	} *cbctx = (void *)cb->ctx;



	ndmsg = nlmsg_data(cb->nlh);

	req_ifindex = ndmsg->ndm_ifindex;



	idx = 0;

	rcu_read_lock();

	list_for_each_entry_rcu(neigh, &net->mctp.neighbours, list) {

		if (idx < cbctx->idx)

			goto cont;



		rc = 0;

		if (req_ifindex == 0 || req_ifindex == neigh->dev->dev->ifindex)

			rc = mctp_fill_neigh(skb, NETLINK_CB(cb->skb).portid,

					     cb->nlh->nlmsg_seq,

					     RTM_NEWNEIGH, NLM_F_MULTI, neigh);



		if (rc)

			break;

cont:

		idx++;

	}

	rcu_read_unlock();



	cbctx->idx = idx;

	return skb->len;

}



int mctp_neigh_lookup(struct mctp_dev *mdev, mctp_eid_t eid, void *ret_hwaddr)

{

	struct net *net = dev_net(mdev->dev);
@@ -111,6 +301,7 @@ static int __net_init mctp_neigh_net_init(struct net *net) 
	struct netns_mctp *ns = &net->mctp;



	INIT_LIST_HEAD(&ns->neighbours);

	mutex_init(&ns->neigh_lock);

	return 0;

}
@@ -132,10 +323,20 @@ static struct pernet_operations mctp_net_ops = { 


int __init mctp_neigh_init(void)

{

	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWNEIGH,

			     mctp_rtm_newneigh, NULL, 0);

	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELNEIGH,

			     mctp_rtm_delneigh, NULL, 0);

	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETNEIGH,

			     NULL, mctp_rtm_getneigh, 0);



	return register_pernet_subsys(&mctp_net_ops);

}



void __exit mctp_neigh_exit(void)

{

	unregister_pernet_subsys(&mctp_net_ops);

	rtnl_unregister(PF_MCTP, RTM_GETNEIGH);

	rtnl_unregister(PF_MCTP, RTM_DELNEIGH);

	rtnl_unregister(PF_MCTP, RTM_NEWNEIGH);

}