getcon(3) — Linux manual page


getcon(3)               SELinux API documentation              getcon(3)

NAME         top

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

       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         top

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

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

       void freecon(char *con);

       void freeconary(char **con);

       int setcon(char *context);

       int setcon_raw(char *context);

DESCRIPTION         top

       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

       getpidcon() returns the process context for the specified PID.

       getpeercon() retrieves context of peer socket, and set *context
       to refer to it, which must be free'd with freecon().

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

       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)

       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

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

RETURN VALUE         top

       On error -1 is returned.  On success 0 is returned.

SEE ALSO         top

       selinux(8), setexeccon(3)

COLOPHON         top

       This page is part of the selinux (Security-Enhanced Linux user-
       space libraries and tools) project.  Information about the
       project can be found at 
       ⟨⟩.  If you have a
       bug report for this manual page, see
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2021-04-01.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-03-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to        21 December 2011                   getcon(3)

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