NAME

       getcon, getprevcon, getpidcon - get SELinux security context of a process

       freecon, freeconary - free memory associated with SELinux security contexts

       getpeercon - get security context of a peer socket

       setcon - set current security context of a process

SYNOPSIS

       #include <selinux/selinux.h>

       int getcon(char **context);

       int getcon_raw(char **context);

       int getprevcon(char **context);

       int getprevcon_raw(char **context);

       int getpidcon(pid_t pid, char **context);

       int getpidcon_raw(pid_t pid, char **context);

       int getpidprevcon(pid_t pid, char **context);

       int getpidprevcon_raw(pid_t pid, char **context);

       int getpeercon(int fd, char **context);

       int getpeercon_raw(int fd, char **context);

       void freecon(char *con);

       void freeconary(char **con);

       int setcon(const char *context);

       int setcon_raw(const char *context);

DESCRIPTION

       getcon()
              retrieves the context of the current process, which must be free'd with freecon().

       getprevcon()
              same as getcon but gets the context before the last exec.

       getpidcon()
              returns the process context for the specified PID, which must be free'd with freecon().

       getpidprevcon()
              returns  the process context before the last exec for the specified PID, which must be free'd with
              freecon().

       getpeercon()
              retrieves the context of the peer socket, which must be free'd with freecon().

       freecon()
              frees the memory allocated for a security context.

              If con is NULL, no operation is performed.

       freeconary()
              frees the memory allocated for a context array.

              If con is NULL, no operation is performed.

       setcon()
              sets the current security context of the process to a new value.  Note that use of  this  function
              requires that the entire application be trusted to maintain any desired separation between the old
              and new security contexts,  unlike  exec-based  transitions  performed  via  setexeccon(3).   When
              possible, decompose your application and use setexeccon(3) and execve(3) instead.

              Since  access  to  file  descriptors  is  revalidated upon use by SELinux, the new context must be
              explicitly authorized in the policy to use the descriptors opened by the old context  if  that  is
              desired.   Otherwise,  attempts  by  the process to use any existing descriptors (including stdin,
              stdout, and stderr) after performing the setcon() will fail.

              A multi-threaded application can perform a setcon() prior to creating any child threads, in  which
              case  all  of  the  child  threads  will inherit the new context.  However, prior to Linux 2.6.28,
              setcon() would fail if there are any other threads running in the same process  since  this  would
              yield  an  inconsistency  among  the  security  contexts of threads sharing the same memory space.
              Since Linux 2.6.28, setcon() is permitted for threads within a multi-threaded process if  the  new
              security  context  is  bounded  by the old security context, where the bounded relation is defined
              through typebounds statements in the policy and guarantees that the new  security  context  has  a
              subset of the permissions of the old security context.

              If  the process was being ptraced at the time of the setcon() operation, ptrace permission will be
              revalidated against the new context and the setcon() will fail if it is not allowed by policy.

       *_raw()
              getcon_raw(),  getprevcon_raw(),  getpidcon_raw(),   getpidprevcon_raw(),   getpeercon_raw()   and
              setcon_raw()  behave  identically  to  their  non-raw  counterparts  but  do  not  perform context
              translation.

RETURN VALUE

       On error -1 is returned with errno set.  On success 0 is returned.

NOTES

       The retrieval functions might return success and set *context to NULL if  and  only  if  SELinux  is  not
       enabled.

       Querying  a  foreign  process  via  its  PID, e.g. getpidcon() or getpidprevcon(), is inherently racy and
       therefore should never be relied upon for security purposes.

SEE ALSO

       selinux(8), setexeccon(3)