phonet netlink: allow multiple messages per skb in route dump (926e9878) · Commits · 戴 / test

My previous patch to this file changed the code to be bug-compatible towards userspace. Unless userspace (which I wasn't able to find) implements the dump reader by hand in a wrong way, this isn't needed. If it uses libnl or similar code putting multiple messages into a single SKB is far more efficient. Change the code to do this. While at it, also clean it up and don't use so many variables - just store the address in the callback args directly. Signed-off-by:

Johannes Berg <johannes.berg@intel.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/phonet/pn_netlink.c

+7 −15

Original line number	Diff line number	Diff line
		@@ -272,31 +272,23 @@ static int route_doit(struct sk_buff skb, struct nlmsghdr nlh)
		static int route_dumpit(struct sk_buff skb, struct netlink_callback cb)
		{
		struct net *net = sock_net(skb->sk);
		u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
		u8 addr;

		rcu_read_lock();
		for (addr = 0; addr < 64; addr++) {
		struct net_device *dev;
		for (addr = cb->args[0]; addr < 64; addr++) {
		struct net_device *dev = phonet_route_get_rcu(net, addr << 2);

		dev = phonet_route_get_rcu(net, addr << 2);
		if (!dev)
		continue;

		if (addr_idx++ < addr_start_idx)
		continue;
		fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid,
		cb->nlh->nlmsg_seq, RTM_NEWROUTE);
		/* fill_route() used to return > 0 (or negative errors) but
		* never 0 - ignore the return value and just go out to
		* call dumpit again from outside to preserve the behavior
		*/
		if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).portid,
		cb->nlh->nlmsg_seq, RTM_NEWROUTE) < 0)
		goto out;
		}

		out:
		rcu_read_unlock();
		cb->args[0] = addr_idx;
		cb->args[1] = 0;
		cb->args[0] = addr;

		return skb->len;
		}

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