Commit 06d2f4c5 authored by Matt Johnston's avatar Matt Johnston Committed by David S. Miller
Browse files

mctp: Add netlink route management 



This change adds RTM_GETROUTE, RTM_NEWROUTE & RTM_DELROUTE handlers,
allowing management of the MCTP route table.

Includes changes from Jeremy Kerr <jk@codeconstruct.com.au>.

Signed-off-by: default avatarMatt Johnston <matt@codeconstruct.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 889b7da2

include/net/mctp.h

+2 −0
Original line number Diff line number Diff line
@@ -111,6 +111,8 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt, 
		      struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);



/* routing <--> device interface */

unsigned int mctp_default_net(struct net *net);

int mctp_default_net_set(struct net *net, unsigned int index);

int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr);

int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr);

void mctp_route_remove_dev(struct mctp_dev *mdev);

net/mctp/route.c

+249 −9
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 


#include <net/mctp.h>

#include <net/mctpdevice.h>

#include <net/netlink.h>

#include <net/sock.h>



/* route output callbacks */

static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
@@ -36,8 +38,7 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb) 
	return 0;

}



static int __always_unused mctp_route_output(struct mctp_route *route,

					     struct sk_buff *skb)

static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)

{

	unsigned int mtu;

	int rc;
@@ -182,20 +183,29 @@ int mctp_local_output(struct sock *sk, struct mctp_route *rt, 
}



/* route management */

int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)

static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,

			  unsigned int daddr_extent, unsigned int mtu,

			  bool is_local)

{

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

	struct mctp_route *rt, *ert;



	if (!mctp_address_ok(daddr_start))

		return -EINVAL;



	if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)

		return -EINVAL;



	rt = mctp_route_alloc();

	if (!rt)

		return -ENOMEM;



	rt->min = addr;

	rt->max = addr;

	rt->min = daddr_start;

	rt->max = daddr_start + daddr_extent;

	rt->mtu = mtu;

	rt->dev = mdev;

	dev_hold(rt->dev->dev);

	rt->output = mctp_route_input;

	rt->output = is_local ? mctp_route_input : mctp_route_output;



	ASSERT_RTNL();

	/* Prevent duplicate identical routes. */
@@ -211,22 +221,43 @@ int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr) 
	return 0;

}



int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)

static int mctp_route_remove(struct mctp_dev *mdev, mctp_eid_t daddr_start,

			     unsigned int daddr_extent)

{

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

	struct mctp_route *rt, *tmp;

	mctp_eid_t daddr_end;

	bool dropped;



	if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)

		return -EINVAL;



	daddr_end = daddr_start + daddr_extent;

	dropped = false;



	ASSERT_RTNL();



	list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {

		if (rt->dev == mdev && rt->min == addr && rt->max == addr) {

		if (rt->dev == mdev &&

		    rt->min == daddr_start && rt->max == daddr_end) {

			list_del_rcu(&rt->list);

			/* TODO: immediate RTM_DELROUTE */

			mctp_route_release(rt);

			dropped = true;

		}

	}



	return 0;

	return dropped ? 0 : -ENOENT;

}



int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)

{

	return mctp_route_add(mdev, addr, 0, 0, true);

}



int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)

{

	return mctp_route_remove(mdev, addr, 0);

}



/* removes all entries for a given device */
@@ -294,6 +325,204 @@ static struct packet_type mctp_packet_type = { 
	.func = mctp_pkttype_receive,

};



/* netlink interface */



static const struct nla_policy rta_mctp_policy[RTA_MAX + 1] = {

	[RTA_DST]		= { .type = NLA_U8 },

	[RTA_METRICS]		= { .type = NLA_NESTED },

	[RTA_OIF]		= { .type = NLA_U32 },

};



/* Common part for RTM_NEWROUTE and RTM_DELROUTE parsing.

 * tb must hold RTA_MAX+1 elements.

 */

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

			      struct netlink_ext_ack *extack,

			      struct nlattr **tb, struct rtmsg **rtm,

			      struct mctp_dev **mdev, mctp_eid_t *daddr_start)

{

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

	struct net_device *dev;

	unsigned int ifindex;

	int rc;



	rc = nlmsg_parse(nlh, sizeof(struct rtmsg), tb, RTA_MAX,

			 rta_mctp_policy, extack);

	if (rc < 0) {

		NL_SET_ERR_MSG(extack, "incorrect format");

		return rc;

	}



	if (!tb[RTA_DST]) {

		NL_SET_ERR_MSG(extack, "dst EID missing");

		return -EINVAL;

	}

	*daddr_start = nla_get_u8(tb[RTA_DST]);



	if (!tb[RTA_OIF]) {

		NL_SET_ERR_MSG(extack, "ifindex missing");

		return -EINVAL;

	}

	ifindex = nla_get_u32(tb[RTA_OIF]);



	*rtm = nlmsg_data(nlh);

	if ((*rtm)->rtm_family != AF_MCTP) {

		NL_SET_ERR_MSG(extack, "route family must be AF_MCTP");

		return -EINVAL;

	}



	dev = __dev_get_by_index(net, ifindex);

	if (!dev) {

		NL_SET_ERR_MSG(extack, "bad ifindex");

		return -ENODEV;

	}

	*mdev = mctp_dev_get_rtnl(dev);

	if (!*mdev)

		return -ENODEV;



	if (dev->flags & IFF_LOOPBACK) {

		NL_SET_ERR_MSG(extack, "no routes to loopback");

		return -EINVAL;

	}



	return 0;

}



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

			 struct netlink_ext_ack *extack)

{

	struct nlattr *tb[RTA_MAX + 1];

	mctp_eid_t daddr_start;

	struct mctp_dev *mdev;

	struct rtmsg *rtm;

	unsigned int mtu;

	int rc;



	rc = mctp_route_nlparse(skb, nlh, extack, tb,

				&rtm, &mdev, &daddr_start);

	if (rc < 0)

		return rc;



	if (rtm->rtm_type != RTN_UNICAST) {

		NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST");

		return -EINVAL;

	}



	/* TODO: parse mtu from nlparse */

	mtu = 0;



	rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu, false);

	return rc;

}



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

			 struct netlink_ext_ack *extack)

{

	struct nlattr *tb[RTA_MAX + 1];

	mctp_eid_t daddr_start;

	struct mctp_dev *mdev;

	struct rtmsg *rtm;

	int rc;



	rc = mctp_route_nlparse(skb, nlh, extack, tb,

				&rtm, &mdev, &daddr_start);

	if (rc < 0)

		return rc;



	/* we only have unicast routes */

	if (rtm->rtm_type != RTN_UNICAST)

		return -EINVAL;



	rc = mctp_route_remove(mdev, daddr_start, rtm->rtm_dst_len);

	return rc;

}



static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt,

			    u32 portid, u32 seq, int event, unsigned int flags)

{

	struct nlmsghdr *nlh;

	struct rtmsg *hdr;

	void *metrics;



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

	if (!nlh)

		return -EMSGSIZE;



	hdr = nlmsg_data(nlh);

	hdr->rtm_family = AF_MCTP;



	/* we use the _len fields as a number of EIDs, rather than

	 * a number of bits in the address

	 */

	hdr->rtm_dst_len = rt->max - rt->min;

	hdr->rtm_src_len = 0;

	hdr->rtm_tos = 0;

	hdr->rtm_table = RT_TABLE_DEFAULT;

	hdr->rtm_protocol = RTPROT_STATIC; /* everything is user-defined */

	hdr->rtm_scope = RT_SCOPE_LINK; /* TODO: scope in mctp_route? */

	hdr->rtm_type = RTN_ANYCAST; /* TODO: type from route */



	if (nla_put_u8(skb, RTA_DST, rt->min))

		goto cancel;



	metrics = nla_nest_start_noflag(skb, RTA_METRICS);

	if (!metrics)

		goto cancel;



	if (rt->mtu) {

		if (nla_put_u32(skb, RTAX_MTU, rt->mtu))

			goto cancel;

	}



	nla_nest_end(skb, metrics);



	if (rt->dev) {

		if (nla_put_u32(skb, RTA_OIF, rt->dev->dev->ifindex))

			goto cancel;

	}



	/* TODO: conditional neighbour physaddr? */



	nlmsg_end(skb, nlh);



	return 0;



cancel:

	nlmsg_cancel(skb, nlh);

	return -EMSGSIZE;

}



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

{

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

	struct mctp_route *rt;

	int s_idx, idx;



	/* TODO: allow filtering on route data, possibly under

	 * cb->strict_check

	 */



	/* TODO: change to struct overlay */

	s_idx = cb->args[0];

	idx = 0;



	rcu_read_lock();

	list_for_each_entry_rcu(rt, &net->mctp.routes, list) {

		if (idx++ < s_idx)

			continue;

		if (mctp_fill_rtinfo(skb, rt,

				     NETLINK_CB(cb->skb).portid,

				     cb->nlh->nlmsg_seq,

				     RTM_NEWROUTE, NLM_F_MULTI) < 0)

			break;

	}



	rcu_read_unlock();

	cb->args[0] = idx;



	return skb->len;

}



/* net namespace implementation */

static int __net_init mctp_routes_net_init(struct net *net)

{
@@ -319,11 +548,22 @@ static struct pernet_operations mctp_net_ops = { 
int __init mctp_routes_init(void)

{

	dev_add_pack(&mctp_packet_type);



	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETROUTE,

			     NULL, mctp_dump_rtinfo, 0);

	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWROUTE,

			     mctp_newroute, NULL, 0);

	rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELROUTE,

			     mctp_delroute, NULL, 0);



	return register_pernet_subsys(&mctp_net_ops);

}



void __exit mctp_routes_exit(void)

{

	unregister_pernet_subsys(&mctp_net_ops);

	rtnl_unregister(PF_MCTP, RTM_DELROUTE);

	rtnl_unregister(PF_MCTP, RTM_NEWROUTE);

	rtnl_unregister(PF_MCTP, RTM_GETROUTE);

	dev_remove_pack(&mctp_packet_type);

}