Commit 5b285cac authored by Patrick McHardy's avatar Patrick McHardy
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ipv6: ip6mr: add support for dumping routing tables over netlink 



The ip6mr /proc interface (ip6_mr_cache) can't be extended to dump routes
from any tables but the main table in a backwards compatible fashion since
the output format ends in a variable amount of output interfaces.

Introduce a new netlink interface to dump multicast routes from all tables,
similar to the netlink interface for regular routes.

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent d1db275d

net/ipv6/ip6mr.c

+89 −7
Original line number Diff line number Diff line
@@ -112,8 +112,10 @@ static int ip6_mr_forward(struct net *net, struct mr6_table *mrt, 
			  struct sk_buff *skb, struct mfc6_cache *cache);

static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,

			      mifi_t mifi, int assert);

static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,

static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,

			       struct mfc6_cache *c, struct rtmsg *rtm);

static int ip6mr_rtm_dumproute(struct sk_buff *skb,

			       struct netlink_callback *cb);

static void mroute_clean_tables(struct mr6_table *mrt);

static void ipmr_expire_process(unsigned long arg);
@@ -1038,7 +1040,7 @@ static void ip6mr_cache_resolve(struct net *net, struct mr6_table *mrt, 
			int err;

			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct ipv6hdr));



			if (ip6mr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {

			if (__ip6mr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {

				nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh;

			} else {

				nlh->nlmsg_type = NLMSG_ERROR;
@@ -1350,6 +1352,7 @@ int __init ip6_mr_init(void) 
		goto add_proto_fail;

	}

#endif

	rtnl_register(RTNL_FAMILY_IP6MR, RTM_GETROUTE, NULL, ip6mr_rtm_dumproute);

	return 0;

#ifdef CONFIG_IPV6_PIMSM_V2

add_proto_fail:
@@ -2007,8 +2010,7 @@ int ip6_mr_input(struct sk_buff *skb) 
}





static int

ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,

static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,

			       struct mfc6_cache *c, struct rtmsg *rtm)

{

	int ct;
@@ -2111,8 +2113,88 @@ int ip6mr_get_route(struct net *net, 
	if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))

		cache->mfc_flags |= MFC_NOTIFY;



	err = ip6mr_fill_mroute(mrt, skb, cache, rtm);

	err = __ip6mr_fill_mroute(mrt, skb, cache, rtm);

	read_unlock(&mrt_lock);

	return err;

}



static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,

			     u32 pid, u32 seq, struct mfc6_cache *c)

{

	struct nlmsghdr *nlh;

	struct rtmsg *rtm;



	nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);

	if (nlh == NULL)

		return -EMSGSIZE;



	rtm = nlmsg_data(nlh);

	rtm->rtm_family   = RTNL_FAMILY_IPMR;

	rtm->rtm_dst_len  = 128;

	rtm->rtm_src_len  = 128;

	rtm->rtm_tos      = 0;

	rtm->rtm_table    = mrt->id;

	NLA_PUT_U32(skb, RTA_TABLE, mrt->id);

	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;

	rtm->rtm_protocol = RTPROT_UNSPEC;

	rtm->rtm_flags    = 0;



	NLA_PUT(skb, RTA_SRC, 16, &c->mf6c_origin);

	NLA_PUT(skb, RTA_DST, 16, &c->mf6c_mcastgrp);



	if (__ip6mr_fill_mroute(mrt, skb, c, rtm) < 0)

		goto nla_put_failure;



	return nlmsg_end(skb, nlh);



nla_put_failure:

	nlmsg_cancel(skb, nlh);

	return -EMSGSIZE;

}



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

{

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

	struct mr6_table *mrt;

	struct mfc6_cache *mfc;

	unsigned int t = 0, s_t;

	unsigned int h = 0, s_h;

	unsigned int e = 0, s_e;



	s_t = cb->args[0];

	s_h = cb->args[1];

	s_e = cb->args[2];



	read_lock(&mrt_lock);

	ip6mr_for_each_table(mrt, net) {

		if (t < s_t)

			goto next_table;

		if (t > s_t)

			s_h = 0;

		for (h = s_h; h < MFC6_LINES; h++) {

			list_for_each_entry(mfc, &mrt->mfc6_cache_array[h], list) {

				if (e < s_e)

					goto next_entry;

				if (ip6mr_fill_mroute(mrt, skb,

						      NETLINK_CB(cb->skb).pid,

						      cb->nlh->nlmsg_seq,

						      mfc) < 0)

					goto done;

next_entry:

				e++;

			}

			e = s_e = 0;

		}

		s_h = 0;

next_table:

		t++;

	}

done:

	read_unlock(&mrt_lock);



	cb->args[2] = e;

	cb->args[1] = h;

	cb->args[0] = t;



	return skb->len;

}

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