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/// \file run.h
/// Structures and functions to run a program in an isolated manner.
///
/// Pretty much all the functions of this module (ab)use global variables to
/// store their state.  This means that they are not reentrant, but this is by
/// design: the whole point of implementing standalone testers is to simplify
/// the writing of this code by being able to make such assumptions.

#if !defined(KYUA_RUN_H)
#define KYUA_RUN_H

#include <stdbool.h>
#include <unistd.h>

#include "defs.h"
#include "error_fwd.h"
#include "run_fwd.h"


extern const char* kyua_run_tmpdir;


/// Parameters that indicate how to isolate a subprocess.
///
/// In the name of simplicity, the fields of this structure can be considered
/// public.
struct kyua_run_params {
    /// Execution deadline for the subprocess.
    unsigned long timeout_seconds;

    /// Work directory for the subprocess to use.
    const char* work_directory;

    /// UID of the user to switch to before running the subprocess.
    uid_t unprivileged_user;

    /// GID of the group to switch to before running the subprocess.
    gid_t unprivileged_group;
};


void kyua_run_params_init(kyua_run_params_t*);


void kyua_run_exec(const char*, const char* const*) KYUA_DEFS_NORETURN;


kyua_error_t kyua_run_fork(const kyua_run_params_t*, pid_t* const);
kyua_error_t kyua_run_wait(const pid_t, int*, bool*);


kyua_error_t kyua_run_work_directory_enter(const char*, const uid_t,
                                           const gid_t, char**);
kyua_error_t kyua_run_work_directory_leave(char**);


#endif  // !defined(KYUA_RUN_H)