Updated: April 19, 2023 |
Handle an _IO_CHOWN message
#include <sys/iofunc.h> int iofunc_chown ( resmgr_context_t *ctp, io_chown_t *msg, iofunc_ocb_t *ocb, iofunc_attr_t *attr );
libc
Use the -l c option to qcc to link against this library. This library is usually included automatically.
The iofunc_chown() helper function implements POSIX semantics for the client's chown() call, which is received as an _IO_CHOWN message by the resource manager.
The iofunc_chown() function calls iofunc_check_access() to verify that the client has the necessary permissions to effect a chown on the attribute. If so, the chown is performed, modifying elements of the ocb->attr structure. As per POSIX 1003.1, if the client isn't root, iofunc_chown() clears the set-user-id and set-group-id bits in the ocb->attr->mode member.
This function takes care of updating the IOFUNC_ATTR_CTIME, IOFUNC_ATTR_DIRTY_TIME, and IOFUNC_ATTR_DIRTY_MODE bits in ocb->attr->flags. You can use iofunc_time_update(), to update the appropriate time fields in ocb->attr.
io_chown_t structure
The io_chown_t structure holds the _IO_CHOWN message received by the resource manager:
struct _io_chown { uint16_t type; uint16_t combine_len; int32_t gid; int32_t uid; }; typedef union { struct _io_chown i; } io_chown_t;
The I/O message structures are unions of an input message (coming to the resource manager) and an output or reply message (going back to the client). In this case, there's only an input message, i.
The i member is a structure of type _io_chown that contains the following members:
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | Yes |
Thread | Yes |