Re: genetlink misinterprets NEW as GET

On 06/01/11 15:25, Jan Engelhardt wrote:

On Thursday 2011-01-06 14:48, Pablo Neira Ayuso wrote:

quoted

quoted

	/* Modifiers to GET request */
	#define NLM_F_ROOT      0x100
	#define NLM_F_MATCH     0x200
	#define NLM_F_ATOMIC    0x400
	#define NLM_F_DUMP      (NLM_F_ROOT|NLM_F_MATCH)
	
	/* Modifiers to NEW request */
	#define NLM_F_REPLACE   0x100
	#define NLM_F_EXCL      0x200
	#define NLM_F_CREATE    0x400
	#define NLM_F_APPEND    0x800

Except there is nothing that declares a particular Netlink message
as "GET" or "NEW". Subsequently, genetlink chokes:

	if (nlh->nlmsg_flags & NLM_F_DUMP)
		if (ops->dumpit == NULL)
			return -EOPNOTSUPP;

Because NLM_F_CREATE | NLM_F_EXCL == NLM_F_DUMP.
That, of course, is absolutely bogus.

Hm, NLM_F_CREATE | NLM_F_EXCL is not equal to NLM_F_DUMP.

You must be hitting -EOPNOTSUPP elsewhere.

No, I am hitting EOPNOTSUPP here; right it's not equal, sorry.
But nlmsg_flags is tested for NLM_F_MATCH (0x200), which is provided by
NLM_F_EXCL. ipset does use NLM_F_EXCL and thus ran into this.

i getting confused, so ipset is also setting NLM_F_REPLACE to match the
NLM_F_DUMP bitmask?