Commit dbdd9a52 authored by David S. Miller's avatar David S. Miller
Browse files

ipv4: Remove redundant RCU locking in ip_check_mc(). 



All callers are under rcu_read_lock() protection already.

Rename to ip_check_mc_rcu() to make it even more clear.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 33175d84

include/linux/igmp.h

+1 −1
Original line number Diff line number Diff line
@@ -217,7 +217,7 @@ struct ip_mc_list { 
#define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)

#define IGMPV3_MRC(value) IGMPV3_EXP(0x80, 4, 3, value)



extern int ip_check_mc(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);

extern int ip_check_mc_rcu(struct in_device *dev, __be32 mc_addr, __be32 src_addr, u16 proto);

extern int igmp_rcv(struct sk_buff *);

extern int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr);

extern int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr);

net/ipv4/igmp.c

+2 −3
Original line number Diff line number Diff line
@@ -2333,13 +2333,13 @@ void ip_mc_drop_socket(struct sock *sk) 
	rtnl_unlock();

}



int ip_check_mc(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)

/* called with rcu_read_lock() */

int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)

{

	struct ip_mc_list *im;

	struct ip_sf_list *psf;

	int rv = 0;



	rcu_read_lock();

	for_each_pmc_rcu(in_dev, im) {

		if (im->multiaddr == mc_addr)

			break;
@@ -2361,7 +2361,6 @@ int ip_check_mc(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 p 
		} else

			rv = 1; /* unspecified source; tentatively allow */

	}

	rcu_read_unlock();

	return rv;

}

net/ipv4/route.c

+4 −4
Original line number Diff line number Diff line
@@ -2309,7 +2309,7 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr, 
		struct in_device *in_dev = __in_dev_get_rcu(dev);



		if (in_dev) {

			int our = ip_check_mc(in_dev, daddr, saddr,

			int our = ip_check_mc_rcu(in_dev, daddr, saddr,

						  ip_hdr(skb)->protocol);

			if (our

#ifdef CONFIG_IP_MROUTE
@@ -2368,7 +2368,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res, 
		fi = NULL;

	} else if (type == RTN_MULTICAST) {

		flags |= RTCF_MULTICAST | RTCF_LOCAL;

		if (!ip_check_mc(in_dev, oldflp->fl4_dst, oldflp->fl4_src,

		if (!ip_check_mc_rcu(in_dev, oldflp->fl4_dst, oldflp->fl4_src,

				     oldflp->proto))

			flags &= ~RTCF_LOCAL;

		/* If multicast route do not exist use