Commit 3493a5b7 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

ip6mr: ip6mr_cache_report() changes 



ip6mr_cache_report() first argument can be marked const, and we change
the caller convention about which lock needs to be held.

Instead of read_lock(&mrt_lock), we can use rcu_read_lock().

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e4cd9868

net/ipv6/ip6mr.c

+20 −15
Original line number Diff line number Diff line
@@ -91,11 +91,11 @@ static void ip6mr_free_table(struct mr_table *mrt); 
static void ip6_mr_forward(struct net *net, struct mr_table *mrt,

			   struct net_device *dev, struct sk_buff *skb,

			   struct mfc6_cache *cache);

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

static int ip6mr_cache_report(const struct mr_table *mrt, struct sk_buff *pkt,

			      mifi_t mifi, int assert);

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);

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

static int ip6mr_rtm_dumproute(struct sk_buff *skb,

			       struct netlink_callback *cb);

static void mroute_clean_tables(struct mr_table *mrt, int flags);
@@ -608,11 +608,12 @@ static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, 
	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)

		goto tx_err;



	read_lock(&mrt_lock);

	dev->stats.tx_bytes += skb->len;

	dev->stats.tx_packets++;

	ip6mr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, MRT6MSG_WHOLEPKT);

	read_unlock(&mrt_lock);

	rcu_read_lock();

	ip6mr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),

			   MRT6MSG_WHOLEPKT);

	rcu_read_unlock();

	kfree_skb(skb);

	return NETDEV_TX_OK;
@@ -718,8 +719,10 @@ static int mif6_delete(struct mr_table *mrt, int vifi, int notify, 
	RCU_INIT_POINTER(v->dev, NULL);



#ifdef CONFIG_IPV6_PIMSM_V2

	if (vifi == mrt->mroute_reg_vif_num)

		mrt->mroute_reg_vif_num = -1;

	if (vifi == mrt->mroute_reg_vif_num) {

		/* Pairs with READ_ONCE() in ip6mr_cache_report() and reg_vif_xmit() */

		WRITE_ONCE(mrt->mroute_reg_vif_num, -1);

	}

#endif



	if (vifi + 1 == mrt->maxvif) {
@@ -922,7 +925,7 @@ static int mif6_add(struct net *net, struct mr_table *mrt, 
	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);

#ifdef CONFIG_IPV6_PIMSM_V2

	if (v->flags & MIFF_REGISTER)

		mrt->mroute_reg_vif_num = vifi;

		WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);

#endif

	if (vifi + 1 > mrt->maxvif)

		mrt->maxvif = vifi + 1;
@@ -1033,10 +1036,10 @@ static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt, 
/*

 *	Bounce a cache query up to pim6sd and netlink.

 *

 *	Called under mrt_lock.

 *	Called under rcu_read_lock()

 */



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

static int ip6mr_cache_report(const struct mr_table *mrt, struct sk_buff *pkt,

			      mifi_t mifi, int assert)

{

	struct sock *mroute6_sk;
@@ -1077,7 +1080,7 @@ static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt, 
		if (assert == MRT6MSG_WRMIFWHOLE)

			msg->im6_mif = mifi;

		else

			msg->im6_mif = mrt->mroute_reg_vif_num;

			msg->im6_mif = READ_ONCE(mrt->mroute_reg_vif_num);

		msg->im6_pad = 0;

		msg->im6_src = ipv6_hdr(pkt)->saddr;

		msg->im6_dst = ipv6_hdr(pkt)->daddr;
@@ -1112,10 +1115,8 @@ static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt, 
	skb->ip_summed = CHECKSUM_UNNECESSARY;

	}



	rcu_read_lock();

	mroute6_sk = rcu_dereference(mrt->mroute_sk);

	if (!mroute6_sk) {

		rcu_read_unlock();

		kfree_skb(skb);

		return -EINVAL;

	}
@@ -1124,7 +1125,7 @@ static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt, 


	/* Deliver to user space multicast routing algorithms */

	ret = sock_queue_rcv_skb(mroute6_sk, skb);

	rcu_read_unlock();



	if (ret < 0) {

		net_warn_ratelimited("mroute6: pending queue full, dropping entries\n");

		kfree_skb(skb);
@@ -2042,7 +2043,9 @@ static int ip6mr_forward2(struct net *net, struct mr_table *mrt, 
		vif->bytes_out += skb->len;

		vif_dev->stats.tx_bytes += skb->len;

		vif_dev->stats.tx_packets++;

		rcu_read_lock();

		ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);

		rcu_read_unlock();

		goto out_free;

	}

#endif
@@ -2155,10 +2158,12 @@ static void ip6_mr_forward(struct net *net, struct mr_table *mrt, 
			       c->_c.mfc_un.res.last_assert +

			       MFC_ASSERT_THRESH)) {

			c->_c.mfc_un.res.last_assert = jiffies;

			rcu_read_lock();

			ip6mr_cache_report(mrt, skb, true_vifi, MRT6MSG_WRONGMIF);

			if (mrt->mroute_do_wrvifwhole)

				ip6mr_cache_report(mrt, skb, true_vifi,

						   MRT6MSG_WRMIFWHOLE);

			rcu_read_unlock();

		}

		goto dont_forward;

	}
@@ -2465,7 +2470,7 @@ static size_t mrt6msg_netlink_msgsize(size_t payloadlen) 
	return len;

}



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

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

{

	struct net *net = read_pnet(&mrt->net);

	struct nlmsghdr *nlh;