Commit 386520e0 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag 



Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDonald Hunter <donald.hunter@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e39951d9

include/linux/netlink.h

+2 −0
Original line number Diff line number Diff line
@@ -291,6 +291,7 @@ struct netlink_callback { 
	u16			answer_flags;

	u32			min_dump_alloc;

	unsigned int		prev_seq, seq;

	int			flags;

	bool			strict_check;

	union {

		u8		ctx[48];
@@ -323,6 +324,7 @@ struct netlink_dump_control { 
	void *data;

	struct module *module;

	u32 min_dump_alloc;

	int flags;

};



int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,

include/net/rtnetlink.h

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *); 
enum rtnl_link_flags {

	RTNL_FLAG_DOIT_UNLOCKED		= BIT(0),

	RTNL_FLAG_BULK_DEL_SUPPORTED	= BIT(1),

	RTNL_FLAG_DUMP_UNLOCKED		= BIT(2),

};



enum rtnl_kinds {

net/core/rtnetlink.c

+2 −0
Original line number Diff line number Diff line
@@ -6532,6 +6532,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 
		}

		owner = link->owner;

		dumpit = link->dumpit;

		flags = link->flags;



		if (type == RTM_GETLINK - RTM_BASE)

			min_dump_alloc = rtnl_calcit(skb, nlh);
@@ -6549,6 +6550,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 
				.dump		= dumpit,

				.min_dump_alloc	= min_dump_alloc,

				.module		= owner,

				.flags		= flags,

			};

			err = netlink_dump_start(rtnl, skb, nlh, &c);

			/* netlink_dump_start() will keep a reference on

net/netlink/af_netlink.c

+3 −0
Original line number Diff line number Diff line
@@ -2261,6 +2261,8 @@ static int netlink_dump(struct sock *sk, bool lock_taken) 


		cb->extack = &extack;



		if (cb->flags & RTNL_FLAG_DUMP_UNLOCKED)

			extra_mutex = NULL;

		if (extra_mutex)

			mutex_lock(extra_mutex);

		nlk->dump_done_errno = cb->dump(skb, cb);
@@ -2355,6 +2357,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 
	cb->data = control->data;

	cb->module = control->module;

	cb->min_dump_alloc = control->min_dump_alloc;

	cb->flags = control->flags;

	cb->skb = skb;



	cb->strict_check = nlk_test_bit(STRICT_CHK, NETLINK_CB(skb).sk);