site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com -josh On Dec 8, 2005, at 11:25 AM, Stephane Sudre wrote: Could there be a problem with the declaration of mbuf_len? size_t mbuf_len(mbuf_t mbuf); size_t is said to be a __darwin_size_t __darwin_size_t is said to be __SIZE_TYPE__ struct m_hdr { struct mbuf *mh_next; /* next buffer in chain */ struct mbuf *mh_nextpkt; /* next chain in queue/record */ long mh_len; /* amount of data in this mbuf */ so mh_len is signed if I'm not mistaken. p *((struct mbuf *) 0x3d1fd100) $3 = { m_hdr = { mh_next = 0x3d221700, mh_nextpkt = 0x0, mh_len = 0, mh_data = 0x3d1fd13b "@\002\001?\b>\006l!E", mh_type = 0, mh_flags = 0 }, .... p *((struct mbuf *) 0x3d221700) $5 = { m_hdr = { mh_next = 0x3d221600, mh_nextpkt = 0xfffffff7, mh_len = -1, mh_data = 0xffffffff <Address 0xffffffff out of bounds>, mh_type = 0, mh_flags = -1 }, and you're testing if (mbuf_len( ) < 0) ... This email sent to jgraessley@apple.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... This email sent to site_archiver@lists.apple.com The mismatch could lead to problems, however, an mbuf length of less than zero is invalid. The length is an absolute length. It makes no sense for it to be less than 0. The internal implementation hasn't switched over to an unsigned type yet. It is conceivable that there are bugs with the conversion between the two. In the long run, the length should be unsigned so the KPI is correct. __SIZE_TYPE__ is said to be long unsigned int (from what I've found with google). My problem is that the m_hdr struct is stating (in the xnu source code): This is a bit "funny" when you're trying to deal with this kind of weird mbuf chain : _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/jgraessley% 40apple.com smime.p7s