Add _IOC_NEWLEN() and _IOC_NEWTYPE() macros.

These macros take an existing ioctl(2) command and replace the length
with the specified length or length of the specified type respectively.
These can be used to define commands for 32-bit compatibility with fewer
opportunities for cut-and-paste errors then a whole new definition.

Reviewed by:	cem, kib
Obtained from:	CheriBSD
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D14706
This commit is contained in:
Brooks Davis 2018-03-16 22:23:04 +00:00
parent a8c03de86d
commit 28e7752907
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=331077

View File

@ -61,6 +61,10 @@
#define _IOW(g,n,t) _IOC(IOC_IN, (g), (n), sizeof(t))
/* this should be _IORW, but stdio got there first */
#define _IOWR(g,n,t) _IOC(IOC_INOUT, (g), (n), sizeof(t))
/* Replace length/type in an ioctl command. */
#define _IOC_NEWLEN(ioc, len) \
(((~(IOCPARM_MASK << 16)) & (ioc)) | (((len) & IOCPARM_MASK) << 16))
#define _IOC_NEWTYPE(ioc, type) _IOC_NEWLEN((ioc), sizeof(type))
#ifdef _KERNEL