Commit 3e41af90 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo() 

Adopt net->dev_by_index as I did in commit 0e0939c0
("net-procfs: use xarray iterator to implement /proc/net/dev")

This makes sure an existing device is always visible in the dump,
regardless of concurrent insertions/deletions.

v2: added suggestions from Jakub Kicinski and Ido Schimmel,
    thanks for the help !

Link: https://lore.kernel.org/all/20240209142441.6c56435b@kernel.org/
Link: https://lore.kernel.org/all/ZckR-XOsULLI9EHc@shredder/


Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240211214404.1882191-3-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent f383ced2

net/core/rtnetlink.c

+20 −38
Original line number Diff line number Diff line
@@ -2188,25 +2188,22 @@ static int rtnl_valid_dump_ifinfo_req(const struct nlmsghdr *nlh, 


static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)

{

	const struct rtnl_link_ops *kind_ops = NULL;

	struct netlink_ext_ack *extack = cb->extack;

	const struct nlmsghdr *nlh = cb->nlh;

	struct net *net = sock_net(skb->sk);

	struct net *tgt_net = net;

	int h, s_h;

	int idx = 0, s_idx;

	struct net_device *dev;

	struct hlist_head *head;

	unsigned int flags = NLM_F_MULTI;

	struct nlattr *tb[IFLA_MAX+1];

	struct {

		unsigned long ifindex;

	} *ctx = (void *)cb->ctx;

	struct net *tgt_net = net;

	u32 ext_filter_mask = 0;

	const struct rtnl_link_ops *kind_ops = NULL;

	unsigned int flags = NLM_F_MULTI;

	struct net_device *dev;

	int master_idx = 0;

	int netnsid = -1;

	int err, i;



	s_h = cb->args[0];

	s_idx = cb->args[1];



	err = rtnl_valid_dump_ifinfo_req(nlh, cb->strict_check, tb, extack);

	if (err < 0) {

		if (cb->strict_check)
@@ -2250,36 +2247,21 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) 
		flags |= NLM_F_DUMP_FILTERED;



walk_entries:

	for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {

		idx = 0;

		head = &tgt_net->dev_index_head[h];

		hlist_for_each_entry(dev, head, index_hlist) {

	err = 0;

	for_each_netdev_dump(tgt_net, dev, ctx->ifindex) {

		if (link_dump_filtered(dev, master_idx, kind_ops))

				goto cont;

			if (idx < s_idx)

				goto cont;

			err = rtnl_fill_ifinfo(skb, dev, net,

					       RTM_NEWLINK,

			continue;

		err = rtnl_fill_ifinfo(skb, dev, net, RTM_NEWLINK,

				       NETLINK_CB(cb->skb).portid,

				       nlh->nlmsg_seq, 0, flags,

				       ext_filter_mask, 0, NULL, 0,

				       netnsid, GFP_KERNEL);



		if (err < 0) {

			if (likely(skb->len))

					goto out;



				goto out_err;

			}

cont:

			idx++;

				err = skb->len;

			break;

		}

	}

out:

	err = skb->len;

out_err:

	cb->args[1] = idx;

	cb->args[0] = h;

	cb->seq = tgt_net->dev_base_seq;

	nl_dump_check_consistent(cb, nlmsg_hdr(skb));

	if (netnsid >= 0)