Commit 4a19edb6 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

netlink: Pass extack to dump handlers 



Declare extack in netlink_dump and pass to dump handlers via
netlink_callback. Add any extack message after the dump_done_errno
allowing error messages to be returned. This will be useful when
strict checking is done on dump requests, returning why the dump
fails EINVAL.

Signed-off-by: default avatarDavid Ahern <dsahern@gmail.com>
Acked-by: default avatarChristian Brauner <christian@brauner.io>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 272a6617

include/linux/netlink.h

+1 −0
Original line number Diff line number Diff line
@@ -176,6 +176,7 @@ struct netlink_callback { 
	void			*data;

	/* the module that dump function belong to */

	struct module		*module;

	struct netlink_ext_ack	*extack;

	u16			family;

	u16			min_dump_alloc;

	unsigned int		prev_seq, seq;

net/netlink/af_netlink.c

+11 −1
Original line number Diff line number Diff line
@@ -2171,6 +2171,7 @@ EXPORT_SYMBOL(__nlmsg_put); 
static int netlink_dump(struct sock *sk)

{

	struct netlink_sock *nlk = nlk_sk(sk);

	struct netlink_ext_ack extack = {};

	struct netlink_callback *cb;

	struct sk_buff *skb = NULL;

	struct nlmsghdr *nlh;
@@ -2222,8 +2223,11 @@ static int netlink_dump(struct sock *sk) 
	skb_reserve(skb, skb_tailroom(skb) - alloc_size);

	netlink_skb_set_owner_r(skb, sk);



	if (nlk->dump_done_errno > 0)

	if (nlk->dump_done_errno > 0) {

		cb->extack = &extack;

		nlk->dump_done_errno = cb->dump(skb, cb);

		cb->extack = NULL;

	}



	if (nlk->dump_done_errno > 0 ||

	    skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
@@ -2246,6 +2250,12 @@ static int netlink_dump(struct sock *sk) 
	memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,

	       sizeof(nlk->dump_done_errno));



	if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) {

		nlh->nlmsg_flags |= NLM_F_ACK_TLVS;

		if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg))

			nlmsg_end(skb, nlh);

	}



	if (sk_filter(sk, skb))

		kfree_skb(skb);

	else