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Commit 288f06a0 authored by Nicolas Dichtel's avatar Nicolas Dichtel Committed by David S. Miller
Browse files

netns: enable to dump full nsid translation table 



Like the previous patch, the goal is to ease to convert nsids from one
netns to another netns.
A new attribute (NETNSA_CURRENT_NSID) is added to the kernel answer when
NETNSA_TARGET_NSID is provided, thus the user can easily convert nsids.

Signed-off-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3a4f68bf

include/uapi/linux/net_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ enum { 
	NETNSA_PID,

	NETNSA_FD,

	NETNSA_TARGET_NSID,

	NETNSA_CURRENT_NSID,

	__NETNSA_MAX,

};

net/core/net_namespace.c

+26 −6
Original line number Diff line number Diff line
@@ -736,6 +736,7 @@ static int rtnl_net_get_size(void) 
{

	return NLMSG_ALIGN(sizeof(struct rtgenmsg))

	       + nla_total_size(sizeof(s32)) /* NETNSA_NSID */

	       + nla_total_size(sizeof(s32)) /* NETNSA_CURRENT_NSID */

	       ;

}
@@ -745,6 +746,8 @@ struct net_fill_args { 
	int flags;

	int cmd;

	int nsid;

	bool add_ref;

	int ref_nsid;

};



static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args)
@@ -763,6 +766,10 @@ static int rtnl_net_fill(struct sk_buff *skb, struct net_fill_args *args) 
	if (nla_put_s32(skb, NETNSA_NSID, args->nsid))

		goto nla_put_failure;



	if (args->add_ref &&

	    nla_put_s32(skb, NETNSA_CURRENT_NSID, args->ref_nsid))

		goto nla_put_failure;



	nlmsg_end(skb, nlh);

	return 0;
@@ -782,7 +789,6 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh, 
		.cmd = RTM_NEWNSID,

	};

	struct net *peer, *target = net;

	bool put_target = false;

	struct nlattr *nla;

	struct sk_buff *msg;

	int err;
@@ -824,7 +830,8 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh, 
			err = PTR_ERR(target);

			goto out;

		}

		put_target = true;

		fillargs.add_ref = true;

		fillargs.ref_nsid = peernet2id(net, peer);

	}



	msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
@@ -844,7 +851,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh, 
err_out:

	nlmsg_free(msg);

out:

	if (put_target)

	if (fillargs.add_ref)

		put_net(target);

	put_net(peer);

	return err;
@@ -852,11 +859,11 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh, 


struct rtnl_net_dump_cb {

	struct net *tgt_net;

	struct net *ref_net;

	struct sk_buff *skb;

	struct net_fill_args fillargs;

	int idx;

	int s_idx;

	bool put_tgt_net;

};



static int rtnl_net_dumpid_one(int id, void *peer, void *data)
@@ -868,6 +875,8 @@ static int rtnl_net_dumpid_one(int id, void *peer, void *data) 
		goto cont;



	net_cb->fillargs.nsid = id;

	if (net_cb->fillargs.add_ref)

		net_cb->fillargs.ref_nsid = __peernet2id(net_cb->ref_net, peer);

	ret = rtnl_net_fill(net_cb->skb, &net_cb->fillargs);

	if (ret < 0)

		return ret;
@@ -904,8 +913,9 @@ static int rtnl_valid_dump_net_req(const struct nlmsghdr *nlh, struct sock *sk, 
					       "Invalid target network namespace id");

				return PTR_ERR(net);

			}

			net_cb->fillargs.add_ref = true;

			net_cb->ref_net = net_cb->tgt_net;

			net_cb->tgt_net = net;

			net_cb->put_tgt_net = true;

		} else {

			NL_SET_BAD_ATTR(extack, tb[i]);

			NL_SET_ERR_MSG(extack,
@@ -940,12 +950,22 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb) 
	}



	spin_lock_bh(&net_cb.tgt_net->nsid_lock);

	if (net_cb.fillargs.add_ref &&

	    !net_eq(net_cb.ref_net, net_cb.tgt_net) &&

	    !spin_trylock_bh(&net_cb.ref_net->nsid_lock)) {

		spin_unlock_bh(&net_cb.tgt_net->nsid_lock);

		err = -EAGAIN;

		goto end;

	}

	idr_for_each(&net_cb.tgt_net->netns_ids, rtnl_net_dumpid_one, &net_cb);

	if (net_cb.fillargs.add_ref &&

	    !net_eq(net_cb.ref_net, net_cb.tgt_net))

		spin_unlock_bh(&net_cb.ref_net->nsid_lock);

	spin_unlock_bh(&net_cb.tgt_net->nsid_lock);



	cb->args[0] = net_cb.idx;

end:

	if (net_cb.put_tgt_net)

	if (net_cb.fillargs.add_ref)

		put_net(net_cb.tgt_net);

	return err < 0 ? err : skb->len;

}