Commit d7c31cbd authored by David Lamparter's avatar David Lamparter Committed by David S. Miller
Browse files

net: ip6mr: add RTM_GETROUTE netlink op 



The IPv6 multicast routing code previously implemented only the dump
variant of RTM_GETROUTE.  Implement single MFC item retrieval by copying
and adapting the respective IPv4 code.

Tested against FRRouting's IPv6 PIM stack.

Signed-off-by: default avatarDavid Lamparter <equinox@diac24.net>
Reviewed-by: default avatarNikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 00cf1fb3

net/ipv6/ip6mr.c

+92 −1
Original line number Diff line number Diff line
@@ -95,6 +95,8 @@ static int ip6mr_cache_report(const struct mr_table *mrt, struct sk_buff *pkt, 
static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,

			      int cmd);

static void mrt6msg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt);

static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,

			      struct netlink_ext_ack *extack);

static int ip6mr_rtm_dumproute(struct sk_buff *skb,

			       struct netlink_callback *cb);

static void mroute_clean_tables(struct mr_table *mrt, int flags);
@@ -1390,7 +1392,7 @@ int __init ip6_mr_init(void) 
	}

#endif

	err = rtnl_register_module(THIS_MODULE, RTNL_FAMILY_IP6MR, RTM_GETROUTE,

				   NULL, ip6mr_rtm_dumproute, 0);

				   ip6mr_rtm_getroute, ip6mr_rtm_dumproute, 0);

	if (err == 0)

		return 0;
@@ -2510,6 +2512,95 @@ static void mrt6msg_netlink_event(const struct mr_table *mrt, struct sk_buff *pk 
	rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE_R, -ENOBUFS);

}



static const struct nla_policy ip6mr_getroute_policy[RTA_MAX + 1] = {

	[RTA_SRC]		= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),

	[RTA_DST]		= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),

	[RTA_TABLE]		= { .type = NLA_U32 },

};



static int ip6mr_rtm_valid_getroute_req(struct sk_buff *skb,

					const struct nlmsghdr *nlh,

					struct nlattr **tb,

					struct netlink_ext_ack *extack)

{

	struct rtmsg *rtm;

	int err;



	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, ip6mr_getroute_policy,

			  extack);

	if (err)

		return err;



	rtm = nlmsg_data(nlh);

	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||

	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||

	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||

	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {

		NL_SET_ERR_MSG_MOD(extack,

				   "Invalid values in header for multicast route get request");

		return -EINVAL;

	}



	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||

	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {

		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");

		return -EINVAL;

	}



	return 0;

}



static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,

			      struct netlink_ext_ack *extack)

{

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

	struct in6_addr src = {}, grp = {};

	struct nlattr *tb[RTA_MAX + 1];

	struct mfc6_cache *cache;

	struct mr_table *mrt;

	struct sk_buff *skb;

	u32 tableid;

	int err;



	err = ip6mr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);

	if (err < 0)

		return err;



	if (tb[RTA_SRC])

		src = nla_get_in6_addr(tb[RTA_SRC]);

	if (tb[RTA_DST])

		grp = nla_get_in6_addr(tb[RTA_DST]);

	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;



	mrt = ip6mr_get_table(net, tableid ?: RT_TABLE_DEFAULT);

	if (!mrt) {

		NL_SET_ERR_MSG_MOD(extack, "MR table does not exist");

		return -ENOENT;

	}



	/* entries are added/deleted only under RTNL */

	rcu_read_lock();

	cache = ip6mr_cache_find(mrt, &src, &grp);

	rcu_read_unlock();

	if (!cache) {

		NL_SET_ERR_MSG_MOD(extack, "MR cache entry not found");

		return -ENOENT;

	}



	skb = nlmsg_new(mr6_msgsize(false, mrt->maxvif), GFP_KERNEL);

	if (!skb)

		return -ENOBUFS;



	err = ip6mr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,

				nlh->nlmsg_seq, cache, RTM_NEWROUTE, 0);

	if (err < 0) {

		kfree_skb(skb);

		return err;

	}



	return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);

}



static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)

{

	const struct nlmsghdr *nlh = cb->nlh;