getpeercon - get security context of a peer socket.
setcon - set current security context of a process.
int getcon(security_context_t *context);
int getprevcon(security_context_t *context);
int getpidcon(pid_t pid, security_context_t *context);
int getpeercon(int fd, security_context_t *context);
int setcon(security_context_t context);
getprevcon same as getcon but gets the context before the last exec.
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.
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 applicaiton and use setexeccon() and execve() 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, setcon() will fail if there are any other threads running in the same process.
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.