Date: Wed, 16 Oct 2013 00:41:13 +1100 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Kevin Lo <kevlo@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r256505 - head/sys/netinet Message-ID: <20131015231355.H1194@besplex.bde.org> In-Reply-To: <201310150735.r9F7ZdIt094705@svn.freebsd.org> References: <201310150735.r9F7ZdIt094705@svn.freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 15 Oct 2013, Kevin Lo wrote: > Log: > Treat INADDR_NONE as uint32_t. > > Reviewed by: glebius > Modified: > head/sys/netinet/in.h > > Modified: head/sys/netinet/in.h > ============================================================================== > --- head/sys/netinet/in.h Tue Oct 15 06:38:40 2013 (r256504) > +++ head/sys/netinet/in.h Tue Oct 15 07:35:39 2013 (r256505) > @@ -379,7 +379,7 @@ __END_DECLS > > #define INADDR_LOOPBACK (u_int32_t)0x7f000001 The old casts of inet address macros are remarkably buggy: - all are missing parentheses. This gives an incorrect parse for weird code like INADDR_LOOPBACK[array] (this syntax is valid but gives different semantics to array[INADDR_LOOPBACK], unlike if the array and the index are either correctly written macros or not macros. - all cast to u_int32_t instead of to in_addr_t. This is not just a style bug. u_int32_t isn't even declared, except accidentally via namespace pollution. > #ifndef _KERNEL > -#define INADDR_NONE 0xffffffff /* -1 return */ > +#define INADDR_NONE (uint32_t)0xffffffff /* -1 return */ This cast has no effect (except to add bugs) on any supported arch, since all supported arches have 32-bit ints. I first thought that this copied all the bugs from one of the old casts. Actually, it uses a not-incorrect type, so its bugs are only: - missing parentheses - the type is not visually identical to the type of an inet address (in_addr_t) - it is a style bug to not be bug for bug compatible with the spelling in the old casts. > #endif > > #define INADDR_UNSPEC_GROUP (u_int32_t)0xe0000000 /* 224.0.0.0 */ > u_int32_t is also used in many non-address macros starting with IN_CLASSA(). These macros don't aren't missing parentheses. I thought that namespace errors in <net/in.h> had all been fixed. It carefully declares in_addr_t and uint32_t, but still uses u_int32_t in the POSIX inet address macros; these macros are also placed before the typedefs. Bruce
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20131015231355.H1194>