ipmr, ip6mr: Unite dumproute flows

The various MFC entries are being held in the same kind of mr_tables
for both ipmr and ip6mr, and their traversal logic is identical.
Also, with the exception of the addresses [and other small tidbits]
the major bulk of the nla setting is identical.

Unite as much of the dumping as possible between the two.
Notice this requires creating an mr_table iterator for each, as the
for-each preprocessor macro can't be used by the common logic.
Signed-off-by: NYuval Mintz <yuvalm@mellanox.com>
Acked-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/linux/mroute_base.h

@@ -170,6 +170,16 @@ void *mr_mfc_find_parent(struct mr_table *mrt,
 void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi);
 void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg);
 
+int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+		   struct mr_mfc *c, struct rtmsg *rtm);
+int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct mr_table *(*iter)(struct net *net,
+					      struct mr_table *mrt),
+		     int (*fill)(struct mr_table *mrt,
+				 struct sk_buff *skb,
+				 u32 portid, u32 seq, struct mr_mfc *c,
+				 int cmd, int flags),
+		     spinlock_t *lock);
 #else
 static inline void vif_device_init(struct vif_device *v,
 				   struct net_device *dev,
@@ -207,6 +217,25 @@ static inline struct mr_mfc *mr_mfc_find_any(struct mr_table *mrt,
 {
 	return NULL;
 }
+
+static inline int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+				 struct mr_mfc *c, struct rtmsg *rtm)
+{
+	return -EINVAL;
+}
+
+static inline int
+mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
+		 struct mr_table *(*iter)(struct net *net,
+					  struct mr_table *mrt),
+		 int (*fill)(struct mr_table *mrt,
+			     struct sk_buff *skb,
+			     u32 portid, u32 seq, struct mr_mfc *c,
+			     int cmd, int flags),
+		 spinlock_t *lock)
+{
+	return -EINVAL;
+}
 #endif
 
 static inline void *mr_mfc_find(struct mr_table *mrt, void *hasharg)

net/ipv4/ipmr.c

@@ -105,8 +105,6 @@ static void ip_mr_forward(struct net *net, struct mr_table *mrt,
 			  struct mfc_cache *cache, 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,
-			      struct mr_mfc *c, struct rtmsg *rtm);
 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 				 int cmd);
 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
@@ -117,6 +115,23 @@ static void ipmr_expire_process(struct timer_list *t);
 #define ipmr_for_each_table(mrt, net) \
 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
 
+static struct mr_table *ipmr_mr_table_iter(struct net *net,
+					   struct mr_table *mrt)
+{
+	struct mr_table *ret;
+
+	if (!mrt)
+		ret = list_entry_rcu(net->ipv4.mr_tables.next,
+				     struct mr_table, list);
+	else
+		ret = list_entry_rcu(mrt->list.next,
+				     struct mr_table, list);
+
+	if (&ret->list == &net->ipv4.mr_tables)
+		return NULL;
+	return ret;
+}
+
 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
@@ -284,6 +299,14 @@ EXPORT_SYMBOL(ipmr_rule_default);
 #define ipmr_for_each_table(mrt, net) \
 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 
+static struct mr_table *ipmr_mr_table_iter(struct net *net,
+					   struct mr_table *mrt)
+{
+	if (!mrt)
+		return net->ipv4.mrt;
+	return NULL;
+}
+
 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 {
 	return net->ipv4.mrt;
@@ -1051,7 +1074,7 @@ static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
 			struct nlmsghdr *nlh = skb_pull(skb,
 							sizeof(struct iphdr));
 
-			if (__ipmr_fill_mroute(mrt, skb, &c->_c,
+			if (mr_fill_mroute(mrt, skb, &c->_c,
 					   nlmsg_data(nlh)) > 0) {
 				nlh->nlmsg_len = skb_tail_pointer(skb) -
 						 (u8 *)nlh;
@@ -2256,66 +2279,6 @@ static int pim_rcv(struct sk_buff *skb)
 }
 #endif
 
-static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
-			      struct mr_mfc *c, struct rtmsg *rtm)
-{
-	struct rta_mfc_stats mfcs;
-	struct nlattr *mp_attr;
-	struct rtnexthop *nhp;
-	unsigned long lastuse;
-	int ct;
-
-	/* If cache is unresolved, don't try to parse IIF and OIF */
-	if (c->mfc_parent >= MAXVIFS) {
-		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
-		return -ENOENT;
-	}
-
-	if (VIF_EXISTS(mrt, c->mfc_parent) &&
-	    nla_put_u32(skb, RTA_IIF,
-			mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
-		return -EMSGSIZE;
-
-	if (c->mfc_flags & MFC_OFFLOAD)
-		rtm->rtm_flags |= RTNH_F_OFFLOAD;
-
-	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
-		return -EMSGSIZE;
-
-	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
-		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
-			struct vif_device *vif;
-
-			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
-				nla_nest_cancel(skb, mp_attr);
-				return -EMSGSIZE;
-			}
-
-			nhp->rtnh_flags = 0;
-			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
-			vif = &mrt->vif_table[ct];
-			nhp->rtnh_ifindex = vif->dev->ifindex;
-			nhp->rtnh_len = sizeof(*nhp);
-		}
-	}
-
-	nla_nest_end(skb, mp_attr);
-
-	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
-	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
-
-	mfcs.mfcs_packets = c->mfc_un.res.pkt;
-	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
-	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
-	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
-	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
-			      RTA_PAD))
-		return -EMSGSIZE;
-
-	rtm->rtm_type = RTN_MULTICAST;
-	return 1;
-}
-
 int ipmr_get_route(struct net *net, struct sk_buff *skb,
 		   __be32 saddr, __be32 daddr,
 		   struct rtmsg *rtm, u32 portid)
@@ -2373,7 +2336,7 @@ int ipmr_get_route(struct net *net, struct sk_buff *skb,
 	}
 
 	read_lock(&mrt_lock);
-	err = __ipmr_fill_mroute(mrt, skb, &cache->_c, rtm);
+	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
 	read_unlock(&mrt_lock);
 	rcu_read_unlock();
 	return err;
@@ -2410,7 +2373,7 @@ static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
 		goto nla_put_failure;
-	err = __ipmr_fill_mroute(mrt, skb, &c->_c, rtm);
+	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
 	/* do not break the dump if cache is unresolved */
 	if (err < 0 && err != -ENOENT)
 		goto nla_put_failure;
@@ -2423,6 +2386,14 @@ static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
+static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
+			     int flags)
+{
+	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
+				cmd, flags);
+}
+
 static size_t mroute_msgsize(bool unresolved, int maxvif)
 {
 	size_t len =
@@ -2596,62 +2567,8 @@ static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
 
 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	struct net *net = sock_net(skb->sk);
-	unsigned int t = 0, s_t;
-	unsigned int e = 0, s_e;
-	struct mr_table *mrt;
-	struct mr_mfc *mfc;
-
-	s_t = cb->args[0];
-	s_e = cb->args[1];
-
-	rcu_read_lock();
-	ipmr_for_each_table(mrt, net) {
-		if (t < s_t)
-			goto next_table;
-		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
-			if (e < s_e)
-				goto next_entry;
-			if (ipmr_fill_mroute(mrt, skb,
-					     NETLINK_CB(cb->skb).portid,
-					     cb->nlh->nlmsg_seq,
-					     (struct mfc_cache *)mfc,
-					     RTM_NEWROUTE, NLM_F_MULTI) < 0)
-				goto done;
-next_entry:
-			e++;
-		}
-		e = 0;
-		s_e = 0;
-
-		spin_lock_bh(&mfc_unres_lock);
-		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
-			if (e < s_e)
-				goto next_entry2;
-			if (ipmr_fill_mroute(mrt, skb,
-					     NETLINK_CB(cb->skb).portid,
-					     cb->nlh->nlmsg_seq,
-					     (struct mfc_cache *)mfc,
-					     RTM_NEWROUTE, NLM_F_MULTI) < 0) {
-				spin_unlock_bh(&mfc_unres_lock);
-				goto done;
-			}
-next_entry2:
-			e++;
-		}
-		spin_unlock_bh(&mfc_unres_lock);
-		e = 0;
-		s_e = 0;
-next_table:
-		t++;
-	}
-done:
-	rcu_read_unlock();
-
-	cb->args[1] = e;
-	cb->args[0] = t;
-
-	return skb->len;
+	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
+				_ipmr_fill_mroute, &mfc_unres_lock);
 }
 
 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {

net/ipv4/ipmr_base.c

@@ -198,3 +198,126 @@ void *mr_mfc_seq_next(struct seq_file *seq, void *v,
 }
 EXPORT_SYMBOL(mr_mfc_seq_next);
 #endif
+
+int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+		   struct mr_mfc *c, struct rtmsg *rtm)
+{
+	struct rta_mfc_stats mfcs;
+	struct nlattr *mp_attr;
+	struct rtnexthop *nhp;
+	unsigned long lastuse;
+	int ct;
+
+	/* If cache is unresolved, don't try to parse IIF and OIF */
+	if (c->mfc_parent >= MAXVIFS) {
+		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
+		return -ENOENT;
+	}
+
+	if (VIF_EXISTS(mrt, c->mfc_parent) &&
+	    nla_put_u32(skb, RTA_IIF,
+			mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
+		return -EMSGSIZE;
+
+	if (c->mfc_flags & MFC_OFFLOAD)
+		rtm->rtm_flags |= RTNH_F_OFFLOAD;
+
+	mp_attr = nla_nest_start(skb, RTA_MULTIPATH);
+	if (!mp_attr)
+		return -EMSGSIZE;
+
+	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
+		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
+			struct vif_device *vif;
+
+			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
+			if (!nhp) {
+				nla_nest_cancel(skb, mp_attr);
+				return -EMSGSIZE;
+			}
+
+			nhp->rtnh_flags = 0;
+			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
+			vif = &mrt->vif_table[ct];
+			nhp->rtnh_ifindex = vif->dev->ifindex;
+			nhp->rtnh_len = sizeof(*nhp);
+		}
+	}
+
+	nla_nest_end(skb, mp_attr);
+
+	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
+	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
+
+	mfcs.mfcs_packets = c->mfc_un.res.pkt;
+	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
+	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
+	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
+	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
+			      RTA_PAD))
+		return -EMSGSIZE;
+
+	rtm->rtm_type = RTN_MULTICAST;
+	return 1;
+}
+EXPORT_SYMBOL(mr_fill_mroute);
+
+int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct mr_table *(*iter)(struct net *net,
+					      struct mr_table *mrt),
+		     int (*fill)(struct mr_table *mrt,
+				 struct sk_buff *skb,
+				 u32 portid, u32 seq, struct mr_mfc *c,
+				 int cmd, int flags),
+		     spinlock_t *lock)
+{
+	unsigned int t = 0, e = 0, s_t = cb->args[0], s_e = cb->args[1];
+	struct net *net = sock_net(skb->sk);
+	struct mr_table *mrt;
+	struct mr_mfc *mfc;
+
+	rcu_read_lock();
+	for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
+		if (t < s_t)
+			goto next_table;
+		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
+			if (e < s_e)
+				goto next_entry;
+			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+				 cb->nlh->nlmsg_seq, mfc,
+				 RTM_NEWROUTE, NLM_F_MULTI) < 0)
+				goto done;
+next_entry:
+			e++;
+		}
+		e = 0;
+		s_e = 0;
+
+		spin_lock_bh(lock);
+		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
+			if (e < s_e)
+				goto next_entry2;
+			if (fill(mrt, skb, NETLINK_CB(cb->skb).portid,
+				 cb->nlh->nlmsg_seq, mfc,
+				 RTM_NEWROUTE, NLM_F_MULTI) < 0) {
+				spin_unlock_bh(lock);
+				goto done;
+			}
+next_entry2:
+			e++;
+		}
+		spin_unlock_bh(lock);
+		e = 0;
+		s_e = 0;
+next_table:
+		t++;
+	}
+done:
+	rcu_read_unlock();
+
+	cb->args[1] = e;
+	cb->args[0] = t;
+
+	return skb->len;
+}
+EXPORT_SYMBOL(mr_rtm_dumproute);

net/ipv6/ip6mr.c

@@ -87,8 +87,6 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
 			   struct sk_buff *skb, struct mfc6_cache *cache);
 static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt,
 			      mifi_t mifi, int assert);
-static int __ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
-			       struct mfc6_cache *c, struct rtmsg *rtm);
 static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
 			      int cmd);
 static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
@@ -101,6 +99,23 @@ static void ipmr_expire_process(struct timer_list *t);
 #define ip6mr_for_each_table(mrt, net) \
 	list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list)
 
+static struct mr_table *ip6mr_mr_table_iter(struct net *net,
+					    struct mr_table *mrt)
+{
+	struct mr_table *ret;
+
+	if (!mrt)
+		ret = list_entry_rcu(net->ipv6.mr6_tables.next,
+				     struct mr_table, list);
+	else
+		ret = list_entry_rcu(mrt->list.next,
+				     struct mr_table, list);
+
+	if (&ret->list == &net->ipv6.mr6_tables)
+		return NULL;
+	return ret;
+}
+
 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
@@ -247,6 +262,14 @@ static void __net_exit ip6mr_rules_exit(struct net *net)
 #define ip6mr_for_each_table(mrt, net) \
 	for (mrt = net->ipv6.mrt6; mrt; mrt = NULL)
 
+static struct mr_table *ip6mr_mr_table_iter(struct net *net,
+					    struct mr_table *mrt)
+{
+	if (!mrt)
+		return net->ipv6.mrt6;
+	return NULL;
+}
+
 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
 {
 	return net->ipv6.mrt6;
@@ -948,7 +971,8 @@ static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt,
 			struct nlmsghdr *nlh = skb_pull(skb,
 							sizeof(struct ipv6hdr));
 
-			if (__ip6mr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
+			if (mr_fill_mroute(mrt, skb, &c->_c,
+					   nlmsg_data(nlh)) > 0) {
 				nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh;
 			} else {
 				nlh->nlmsg_type = NLMSG_ERROR;
@@ -2081,63 +2105,6 @@ int ip6_mr_input(struct sk_buff *skb)
 	return 0;
 }
 
-
-static int __ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
-			       struct mfc6_cache *c, struct rtmsg *rtm)
-{
-	struct rta_mfc_stats mfcs;
-	struct nlattr *mp_attr;
-	struct rtnexthop *nhp;
-	unsigned long lastuse;
-	int ct;
-
-	/* If cache is unresolved, don't try to parse IIF and OIF */
-	if (c->_c.mfc_parent >= MAXMIFS) {
-		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
-		return -ENOENT;
-	}
-
-	if (VIF_EXISTS(mrt, c->_c.mfc_parent) &&
-	    nla_put_u32(skb, RTA_IIF,
-			mrt->vif_table[c->_c.mfc_parent].dev->ifindex) < 0)
-		return -EMSGSIZE;
-	mp_attr = nla_nest_start(skb, RTA_MULTIPATH);
-	if (!mp_attr)
-		return -EMSGSIZE;
-
-	for (ct = c->_c.mfc_un.res.minvif;
-	     ct < c->_c.mfc_un.res.maxvif; ct++) {
-		if (VIF_EXISTS(mrt, ct) && c->_c.mfc_un.res.ttls[ct] < 255) {
-			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
-			if (!nhp) {
-				nla_nest_cancel(skb, mp_attr);
-				return -EMSGSIZE;
-			}
-
-			nhp->rtnh_flags = 0;
-			nhp->rtnh_hops = c->_c.mfc_un.res.ttls[ct];
-			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
-			nhp->rtnh_len = sizeof(*nhp);
-		}
-	}
-
-	nla_nest_end(skb, mp_attr);
-
-	lastuse = READ_ONCE(c->_c.mfc_un.res.lastuse);
-	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
-
-	mfcs.mfcs_packets = c->_c.mfc_un.res.pkt;
-	mfcs.mfcs_bytes = c->_c.mfc_un.res.bytes;
-	mfcs.mfcs_wrong_if = c->_c.mfc_un.res.wrong_if;
-	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
-	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
-			      RTA_PAD))
-		return -EMSGSIZE;
-
-	rtm->rtm_type = RTN_MULTICAST;
-	return 1;
-}
-
 int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
 		    u32 portid)
 {
@@ -2203,7 +2170,7 @@ int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
 		return err;
 	}
 
-	err = __ip6mr_fill_mroute(mrt, skb, cache, rtm);
+	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
 	read_unlock(&mrt_lock);
 	return err;
 }
@@ -2239,7 +2206,7 @@ static int ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 	if (nla_put_in6_addr(skb, RTA_SRC, &c->mf6c_origin) ||
 	    nla_put_in6_addr(skb, RTA_DST, &c->mf6c_mcastgrp))
 		goto nla_put_failure;
-	err = __ip6mr_fill_mroute(mrt, skb, c, rtm);
+	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
 	/* do not break the dump if cache is unresolved */
 	if (err < 0 && err != -ENOENT)
 		goto nla_put_failure;
@@ -2252,6 +2219,14 @@ static int ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 	return -EMSGSIZE;
 }
 
+static int _ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
+			      u32 portid, u32 seq, struct mr_mfc *c,
+			      int cmd, int flags)
+{
+	return ip6mr_fill_mroute(mrt, skb, portid, seq, (struct mfc6_cache *)c,
+				 cmd, flags);
+}
+
 static int mr6_msgsize(bool unresolved, int maxvif)
 {
 	size_t len =
@@ -2365,59 +2340,6 @@ static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
 
 static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
 {
-	struct net *net = sock_net(skb->sk);
-	unsigned int t = 0, s_t;
-	unsigned int e = 0, s_e;
-	struct mr_table *mrt;
-	struct mr_mfc *mfc;
-
-	s_t = cb->args[0];
-	s_e = cb->args[1];
-
-	rcu_read_lock();
-	ip6mr_for_each_table(mrt, net) {
-		if (t < s_t)
-			goto next_table;
-		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
-			if (e < s_e)
-				goto next_entry;
-			if (ip6mr_fill_mroute(mrt, skb,
-					      NETLINK_CB(cb->skb).portid,
-					      cb->nlh->nlmsg_seq,
-					      (struct mfc6_cache *)mfc,
-					      RTM_NEWROUTE, NLM_F_MULTI) < 0)
-				goto done;
-next_entry:
-			e++;
-		}
-		e = 0;
-		s_e = 0;
-
-		spin_lock_bh(&mfc_unres_lock);
-		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
-			if (e < s_e)
-				goto next_entry2;
-			if (ip6mr_fill_mroute(mrt, skb,
-					      NETLINK_CB(cb->skb).portid,
-					      cb->nlh->nlmsg_seq,
-					     (struct mfc6_cache *)mfc,
-					      RTM_NEWROUTE, NLM_F_MULTI) < 0) {
-				spin_unlock_bh(&mfc_unres_lock);
-				goto done;
-			}
-next_entry2:
-			e++;
-		}
-		spin_unlock_bh(&mfc_unres_lock);
-		e = s_e = 0;
-next_table:
-		t++;
-	}
-done:
-	rcu_read_unlock();
-
-	cb->args[1] = e;
-	cb->args[0] = t;
-
-	return skb->len;
+	return mr_rtm_dumproute(skb, cb, ip6mr_mr_table_iter,
+				_ip6mr_fill_mroute, &mfc_unres_lock);
 }