Commit cb6a4e46 authored by Patrick McHardy's avatar Patrick McHardy
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net: ipmr: add support for dumping routing tables over netlink 



The ipmr /proc interface (ip_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 25239cee

net/ipv4/ipmr.c

+89 −7
Original line number Diff line number Diff line
@@ -128,7 +128,7 @@ static int ip_mr_forward(struct net *net, struct mr_table *mrt, 
			 int local);

static int ipmr_cache_report(struct mr_table *mrt,

			     struct sk_buff *pkt, vifi_t vifi, int assert);

static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,

static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,

			      struct mfc_cache *c, struct rtmsg *rtm);

static void ipmr_expire_process(unsigned long arg);
@@ -831,7 +831,7 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt, 
		if (ip_hdr(skb)->version == 0) {

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



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

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

				nlh->nlmsg_len = (skb_tail_pointer(skb) -

						  (u8 *)nlh);

			} else {
@@ -1904,9 +1904,8 @@ drop: 
}

#endif



static int

ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, struct mfc_cache *c,

		 struct rtmsg *rtm)

static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,

			      struct mfc_cache *c, struct rtmsg *rtm)

{

	int ct;

	struct rtnexthop *nhp;
@@ -1994,11 +1993,93 @@ int ipmr_get_route(struct net *net, 


	if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))

		cache->mfc_flags |= MFC_NOTIFY;

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

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

	read_unlock(&mrt_lock);

	return err;

}



static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,

			    u32 pid, u32 seq, struct mfc_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  = 32;

	rtm->rtm_src_len  = 32;

	rtm->rtm_tos      = 0;

	rtm->rtm_table    = mrt->id;

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

	rtm->rtm_type     = RTN_MULTICAST;

	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;

	rtm->rtm_protocol = RTPROT_UNSPEC;

	rtm->rtm_flags    = 0;



	NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);

	NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);



	if (__ipmr_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 ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)

{

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

	struct mr_table *mrt;

	struct mfc_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);

	ipmr_for_each_table(mrt, net) {

		if (t < s_t)

			goto next_table;

		if (t > s_t)

			s_h = 0;

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

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

				if (e < s_e)

					goto next_entry;

				if (ipmr_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;

}



#ifdef CONFIG_PROC_FS

/*

 *	The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif
@@ -2355,6 +2436,7 @@ int __init ip_mr_init(void) 
		goto add_proto_fail;

	}

#endif

	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);

	return 0;



#ifdef CONFIG_IP_PIMSM_V2

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