Module: Process::UID

Defined in:: process.c

Overview

The Process::UID module contains a collection of module functions which can be used to portably get, set, and switch the current process's real, effective, and saved user IDs.

Class Method Summary (collapse)

+ (Fixnum) Process::UID.change_privilege(integer)

Change the current process's real and effective user ID to that specified by integer.
+ (Object) eid

Returns the effective user ID for this process.
+ (Object) grant_privilege

Set the effective user ID, and if possible, the saved user ID of the process to the given integer.
+ (Fixnum) Process::UID.re_exchange

Exchange real and effective user IDs and return the new effective user ID.
+ (Boolean) Process::UID.re_exchangeable?

Returns true if the real and effective user IDs of a process may be exchanged on the current platform.
+ (Object) rid

Returns the (real) user ID of this process.
+ (Boolean) Process::UID.sid_available?

Returns true if the current platform has saved user ID functionality.
+ (Object) switch

Switch the effective and real user IDs of the current process.

Class Method Details

+ (`Fixnum`) Process::UID.change_privilege(integer)

Change the current process's real and effective user ID to that specified by integer. Returns the new user ID. Not available on all platforms.

[Process.uid, Process.euid]          #=> [0, 0]
Process::UID.change_privilege(31)    #=> 31
[Process.uid, Process.euid]          #=> [31, 31]

Returns:

(Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.change_privilege(integer)   -> fixnum
 *
 *  Change the current process's real and effective user ID to that
 *  specified by _integer_. Returns the new user ID. Not
 *  available on all platforms.
 *
 *     [Process.uid, Process.euid]          #=> [0, 0]
 *     Process::UID.change_privilege(31)    #=> 31
 *     [Process.uid, Process.euid]          #=> [31, 31]
 */

static VALUE
p_uid_change_privilege(VALUE obj, VALUE id)
{
    rb_uid_t uid;

    check_uid_switch();

    uid = NUM2UIDT(id);

    if (geteuid() == 0) { /* root-user */
#if defined(HAVE_SETRESUID)
    if (setresuid(uid, uid, uid) < 0) rb_sys_fail(0);
    SAVED_USER_ID = uid;
#elif defined(HAVE_SETUID)
    if (setuid(uid) < 0) rb_sys_fail(0);
    SAVED_USER_ID = uid;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
    if (getuid() == uid) {
        if (SAVED_USER_ID == uid) {
        if (setreuid(-1, uid) < 0) rb_sys_fail(0);
        } else {
        if (uid == 0) { /* (r,e,s) == (root, root, x) */
            if (setreuid(-1, SAVED_USER_ID) < 0) rb_sys_fail(0);
            if (setreuid(SAVED_USER_ID, 0) < 0) rb_sys_fail(0);
            SAVED_USER_ID = 0; /* (r,e,s) == (x, root, root) */
            if (setreuid(uid, uid) < 0) rb_sys_fail(0);
            SAVED_USER_ID = uid;
        } else {
            if (setreuid(0, -1) < 0) rb_sys_fail(0);
            SAVED_USER_ID = 0;
            if (setreuid(uid, uid) < 0) rb_sys_fail(0);
            SAVED_USER_ID = uid;
        }
        }
    } else {
        if (setreuid(uid, uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
    }
#elif defined(HAVE_SETRUID) && defined(HAVE_SETEUID)
    if (getuid() == uid) {
        if (SAVED_USER_ID == uid) {
        if (seteuid(uid) < 0) rb_sys_fail(0);
        } else {
        if (uid == 0) {
            if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
            SAVED_USER_ID = 0;
            if (setruid(0) < 0) rb_sys_fail(0);
        } else {
            if (setruid(0) < 0) rb_sys_fail(0);
            SAVED_USER_ID = 0;
            if (seteuid(uid) < 0) rb_sys_fail(0);
            if (setruid(uid) < 0) rb_sys_fail(0);
            SAVED_USER_ID = uid;
        }
        }
    } else {
        if (seteuid(uid) < 0) rb_sys_fail(0);
        if (setruid(uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
    }
#else
    rb_notimplement();
#endif
    } else { /* unprivileged user */
#if defined(HAVE_SETRESUID)
    if (setresuid((getuid() == uid)? -1: uid,
              (geteuid() == uid)? -1: uid,
              (SAVED_USER_ID == uid)? -1: uid) < 0) rb_sys_fail(0);
    SAVED_USER_ID = uid;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
    if (SAVED_USER_ID == uid) {
        if (setreuid((getuid() == uid)? -1: uid,
             (geteuid() == uid)? -1: uid) < 0) rb_sys_fail(0);
    } else if (getuid() != uid) {
        if (setreuid(uid, (geteuid() == uid)? -1: uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
    } else if (/* getuid() == uid && */ geteuid() != uid) {
        if (setreuid(geteuid(), uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
        if (setreuid(uid, -1) < 0) rb_sys_fail(0);
    } else { /* getuid() == uid && geteuid() == uid */
        if (setreuid(-1, SAVED_USER_ID) < 0) rb_sys_fail(0);
        if (setreuid(SAVED_USER_ID, uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
        if (setreuid(uid, -1) < 0) rb_sys_fail(0);
    }
#elif defined(HAVE_SETRUID) && defined(HAVE_SETEUID)
    if (SAVED_USER_ID == uid) {
        if (geteuid() != uid && seteuid(uid) < 0) rb_sys_fail(0);
        if (getuid() != uid && setruid(uid) < 0) rb_sys_fail(0);
    } else if (/* SAVED_USER_ID != uid && */ geteuid() == uid) {
        if (getuid() != uid) {
        if (setruid(uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
        } else {
        if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
        if (setruid(uid) < 0) rb_sys_fail(0);
        }
    } else if (/* geteuid() != uid && */ getuid() == uid) {
        if (seteuid(uid) < 0) rb_sys_fail(0);
        if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
        if (setruid(uid) < 0) rb_sys_fail(0);
    } else {
        errno = EPERM;
        rb_sys_fail(0);
    }
#elif defined HAVE_44BSD_SETUID
    if (getuid() == uid) {
        /* (r,e,s)==(uid,?,?) ==> (uid,uid,uid) */
        if (setuid(uid) < 0) rb_sys_fail(0);
        SAVED_USER_ID = uid;
    } else {
        errno = EPERM;
        rb_sys_fail(0);
    }
#elif defined HAVE_SETEUID
    if (getuid() == uid && SAVED_USER_ID == uid) {
        if (seteuid(uid) < 0) rb_sys_fail(0);
    } else {
        errno = EPERM;
        rb_sys_fail(0);
    }
#elif defined HAVE_SETUID
    if (getuid() == uid && SAVED_USER_ID == uid) {
        if (setuid(uid) < 0) rb_sys_fail(0);
    } else {
        errno = EPERM;
        rb_sys_fail(0);
    }
#else
    rb_notimplement();
#endif
    }
    return id;
}

+ (`Fixnum`) euid + (`Fixnum`) Process::UID.eid + (`Fixnum`) Process::Sys.geteuid

Returns the effective user ID for this process.

Process.euid   #=> 501

Overloads:

+ (Fixnum) euid
Returns:
- (Fixnum)
+ (Fixnum) Process::UID.eid
Returns:
- (Fixnum)
+ (Fixnum) Process::Sys.geteuid
Returns:
- (Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     Process.euid           -> fixnum
 *     Process::UID.eid       -> fixnum
 *     Process::Sys.geteuid   -> fixnum
 *
 *  Returns the effective user ID for this process.
 *
 *     Process.euid   #=> 501
 */

static VALUE
proc_geteuid(VALUE obj)
{
    rb_uid_t euid = geteuid();
    return UIDT2NUM(euid);
}

+ (`Fixnum`) Process::UID.grant_privilege(integer) + (`Fixnum`) Process::UID.eid=(integer)

Set the effective user ID, and if possible, the saved user ID of the process to the given integer. Returns the new effective user ID. Not available on all platforms.

[Process.uid, Process.euid]          #=> [0, 0]
Process::UID.grant_privilege(31)     #=> 31
[Process.uid, Process.euid]          #=> [0, 31]

Overloads:

+ (Fixnum) Process::UID.grant_privilege(integer)
Returns:
- (Fixnum)
+ (Fixnum) Process::UID.eid=(integer)
Returns:
- (Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.grant_privilege(integer)   -> fixnum
 *     Process::UID.eid= integer               -> fixnum
 *
 *  Set the effective user ID, and if possible, the saved user ID of
 *  the process to the given _integer_. Returns the new
 *  effective user ID. Not available on all platforms.
 *
 *     [Process.uid, Process.euid]          #=> [0, 0]
 *     Process::UID.grant_privilege(31)     #=> 31
 *     [Process.uid, Process.euid]          #=> [0, 31]
 */

static VALUE
p_uid_grant_privilege(VALUE obj, VALUE id)
{
    rb_seteuid_core(NUM2UIDT(id));
    return id;
}

+ (`Fixnum`) Process::UID.re_exchange

Exchange real and effective user IDs and return the new effective user ID. Not available on all platforms.

[Process.uid, Process.euid]   #=> [0, 31]
Process::UID.re_exchange      #=> 0
[Process.uid, Process.euid]   #=> [31, 0]

Returns:

(Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.re_exchange   -> fixnum
 *
 *  Exchange real and effective user IDs and return the new effective
 *  user ID. Not available on all platforms.
 *
 *     [Process.uid, Process.euid]   #=> [0, 31]
 *     Process::UID.re_exchange      #=> 0
 *     [Process.uid, Process.euid]   #=> [31, 0]
 */

static VALUE
p_uid_exchange(VALUE obj)
{
    rb_uid_t uid, euid;

    check_uid_switch();

    uid = getuid();
    euid = geteuid();

#if defined(HAVE_SETRESUID)
    if (setresuid(euid, uid, uid) < 0) rb_sys_fail(0);
    SAVED_USER_ID = uid;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
    if (setreuid(euid,uid) < 0) rb_sys_fail(0);
    SAVED_USER_ID = uid;
#else
    rb_notimplement();
#endif
    return UIDT2NUM(uid);
}

+ (`Boolean`) Process::UID.re_exchangeable?

Returns true if the real and effective user IDs of a process may be exchanged on the current platform.

Returns:

(Boolean)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.re_exchangeable?   -> true or false
 *
 *  Returns +true+ if the real and effective user IDs of a
 *  process may be exchanged on the current platform.
 *
 */

static VALUE
p_uid_exchangeable(void)
{
#if defined(HAVE_SETRESUID)
    return Qtrue;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
    return Qtrue;
#else
    return Qfalse;
#endif
}

+ (`Fixnum`) uid + (`Fixnum`) Process::UID.rid + (`Fixnum`) Process::Sys.getuid

Returns the (real) user ID of this process.

Process.uid   #=> 501

Overloads:

+ (Fixnum) uid
Returns:
- (Fixnum)
+ (Fixnum) Process::UID.rid
Returns:
- (Fixnum)
+ (Fixnum) Process::Sys.getuid
Returns:
- (Fixnum)

# File 'process.c'

/*
 *  call-seq:
 *     Process.uid           -> fixnum
 *     Process::UID.rid      -> fixnum
 *     Process::Sys.getuid   -> fixnum
 *
 *  Returns the (real) user ID of this process.
 *
 *     Process.uid   #=> 501
 */

static VALUE
proc_getuid(VALUE obj)
{
    rb_uid_t uid = getuid();
    return UIDT2NUM(uid);
}

+ (`Boolean`) Process::UID.sid_available?

Returns true if the current platform has saved user ID functionality.

Returns:

(Boolean)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.sid_available?   -> true or false
 *
 *  Returns +true+ if the current platform has saved user
 *  ID functionality.
 *
 */

static VALUE
p_uid_have_saved_id(void)
{
#if defined(HAVE_SETRESUID) || defined(HAVE_SETEUID) || defined(_POSIX_SAVED_IDS)
    return Qtrue;
#else
    return Qfalse;
#endif
}

+ (`Fixnum`) Process::UID.switch + (`Object`) Process::UID.switch { ... }

Switch the effective and real user IDs of the current process. If a block is given, the user IDs will be switched back after the block is executed. Returns the new effective user ID if called without a block, and the return value of the block if one is given.

Overloads:

+ (Fixnum) Process::UID.switch
Returns:
- (Fixnum)
+ (Object) Process::UID.switch { ... }
Yields:
Returns:
- (Object)

# File 'process.c'

/*
 *  call-seq:
 *     Process::UID.switch              -> fixnum
 *     Process::UID.switch {|| block}   -> object
 *
 *  Switch the effective and real user IDs of the current process. If
 *  a <em>block</em> is given, the user IDs will be switched back
 *  after the block is executed. Returns the new effective user ID if
 *  called without a block, and the return value of the block if one
 *  is given.
 *
 */

static VALUE
p_uid_switch(VALUE obj)
{
    rb_uid_t uid, euid;

    check_uid_switch();

    uid = getuid();
    euid = geteuid();

    if (uid != euid) {
    proc_seteuid(obj, UIDT2NUM(uid));
    if (rb_block_given_p()) {
        under_uid_switch = 1;
        return rb_ensure(rb_yield, Qnil, p_uid_sw_ensure, SAVED_USER_ID);
    } else {
        return UIDT2NUM(euid);
    }
    } else if (euid != SAVED_USER_ID) {
    proc_seteuid(obj, UIDT2NUM(SAVED_USER_ID));
    if (rb_block_given_p()) {
        under_uid_switch = 1;
        return rb_ensure(rb_yield, Qnil, p_uid_sw_ensure, euid);
    } else {
        return UIDT2NUM(uid);
    }
    } else {
    errno = EPERM;
    rb_sys_fail(0);
    }
}

Module: Process::UID

Overview

Class Method Summary (collapse)

Class Method Details

+ (Fixnum) Process::UID.change_privilege(integer)

+ (Fixnum) euid + (Fixnum) Process::UID.eid + (Fixnum) Process::Sys.geteuid

+ (Fixnum) Process::UID.grant_privilege(integer) + (Fixnum) Process::UID.eid=(integer)

+ (Fixnum) Process::UID.re_exchange

+ (Boolean) Process::UID.re_exchangeable?

+ (Fixnum) uid + (Fixnum) Process::UID.rid + (Fixnum) Process::Sys.getuid

+ (Boolean) Process::UID.sid_available?

+ (Fixnum) Process::UID.switch + (Object) Process::UID.switch { ... }

+ (`Fixnum`) Process::UID.change_privilege(integer)

+ (`Fixnum`) euid + (`Fixnum`) Process::UID.eid + (`Fixnum`) Process::Sys.geteuid

+ (`Fixnum`) Process::UID.grant_privilege(integer) + (`Fixnum`) Process::UID.eid=(integer)

+ (`Fixnum`) Process::UID.re_exchange

+ (`Boolean`) Process::UID.re_exchangeable?

+ (`Fixnum`) uid + (`Fixnum`) Process::UID.rid + (`Fixnum`) Process::Sys.getuid

+ (`Boolean`) Process::UID.sid_available?

+ (`Fixnum`) Process::UID.switch + (`Object`) Process::UID.switch { ... }