NAME

       avc_context_to_sid,   avc_sid_to_context,  avc_get_initial_sid  -  obtain  and  manipulate
       SELinux security ID's

SYNOPSIS

       #include <selinux/selinux.h>
       #include <selinux/avc.h>

       int avc_context_to_sid(char *ctx, security_id_t *sid);

       int avc_sid_to_context(security_id_t sid, char **ctx);

       int avc_get_initial_sid(const char *name, security_id_t *sid);

DESCRIPTION

       Security ID's (SID's) are opaque representations of  security  contexts,  managed  by  the
       userspace AVC.

       avc_context_to_sid() returns a SID for the given context in the memory referenced by sid.

       avc_sid_to_context()  returns  a  copy  of  the  context  represented by sid in the memory
       referenced by ctx.  The user must free the copy with freecon(3).

       avc_get_initial_sid() returns a SID for the kernel initial security  identifier  specified
       by name.

RETURN VALUE

       avc_context_to_sid()  and  avc_sid_to_context()  return  zero on success.  On error, -1 is
       returned and errno is set appropriately.

ERRORS

       ENOMEM An attempt to allocate memory failed.

NOTES

       As of libselinux version 2.0.86, SID's are no longer reference counted.   A  SID  will  be
       valid  from  the  time  it  is  first obtained until the next call to avc_destroy(3).  The
       sidget(3) and sidput(3) functions, formerly used to adjust the reference count, are no-ops
       and are deprecated.

AUTHOR

       Eamon Walsh <ewalsh@tycho.nsa.gov>

SEE ALSO

       avc_init(3), avc_has_perm(3), avc_cache_stats(3), avc_add_callback(3), getcon(3),
       freecon(3), selinux(8)

                                           27 May 2004                      avc_context_to_sid(3)