prop_copyin_ioctl(9) - NetBSD Manual Pages

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PROP_COPYIN_IOCTL(9)   NetBSD Kernel Developer's Manual   PROP_COPYIN_IOCTL(9)


NAME

     prop_object_copyin, prop_object_copyin_size, prop_object_copyin_ioctl,
     prop_object_copyin_ioctl_size, prop_object_copyout,
     prop_object_copyout_ioctl -- Copy property lists to and from kernel space


SYNOPSIS

     #include <prop/proplib.h>

     int
     prop_object_copyin(const struct plistref *pref, prop_object_t *arrayp);

     int
     prop_object_copyin_size(const struct plistref *pref,
         prop_object_t *arrayp, size_t lim);

     int
     prop_object_copyin_ioctl(const struct plistref *pref, const u_long cmd,
         prop_object_t *arrayp);

     int
     prop_object_copyin_ioctl_size(const struct plistref *pref,
         const u_long cmd, prop_object_t *arrayp, size_t lim);

     int
     prop_object_copyout(struct plistref *pref, prop_object_t array);

     int
     prop_object_copyout_ioctl(struct plistref *pref, const u_long cmd,
         prop_object_t array);


DESCRIPTION

     The prop_object_copyin_ioctl, prop_object_copyin_ioctl_size, and
     prop_object_copyout_ioctl functions implement the kernel side of a proto-
     col for copying property lists to and from the kernel using ioctl(2).
     The functions prop_object_copyin, prop_object_copyin_size, and
     prop_object_copyout implement the kernel side of a protocol for copying
     property lists to the kernel as arguments of normal system calls.

     A kernel routine receiving or returning a property list will be passed a
     pointer to a struct plistref.  This structure encapsulates the reference
     to the property list in externalized form.

     The functions prop_object_copyin_size and prop_object_copyin_ioctl_size
     take an explicit size limit argument lim while prop_object_copyin and
     prop_object_copyin_ioctl have an implicit size limit of 128KB.  Attempts
     to transfer objects larger than the limit result in an E2BIG return
     value.

     The functions prop_array_copyin(), prop_array_copyin_size(),
     prop_array_copyin_ioctl(), prop_array_copyin_ioctl_size(),
     prop_dictionary_copyin(), prop_dictionary_copyin_size(),
     prop_dictionary_copyin_ioctl(), and prop_dictionary_copyin_ioctl_size()
     are provided as wrappers around the corresponding generic object func-
     tions.  They are provided for backwards compatibility and will fail if
     the object copied in is not of the specified type, preserving the previ-
     ous behavior.

     The functions prop_array_copyout(), prop_array_copyout_ioctl(),
     prop_dictionary_copyout(), and prop_dictionary_copyout_ioctl() are also
     provided as backwards compatibility wrappers around the corresponding
     generic object functions, but impose no object type constraints.


RETURN VALUES

     If successful, functions return zero.  Otherwise, an error number will be
     returned to indicate the error.


EXAMPLES

     The following (simplified) example demonstrates using
     prop_object_copyin_ioctl() and prop_object_copyout_ioctl() in an ioctl
     routine:

     extern prop_dictionary_t fooprops;

     int
     fooioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
     {
         prop_dictionary_t dict, odict;
         int error;

         switch (cmd) {
         case FOOSETPROPS: {
             const struct plistref *pref = (const struct plistref *) data;
             error = prop_object_copyin_ioctl(pref, cmd,
                 (prop_object_t *)&dict);
             if (error)
                     return (error);
             odict = fooprops;
             fooprops = dict;
             prop_object_release(odict);
             break;
           }

         case FOOGETPROPS: {
             struct plistref *pref = (struct plistref *) data;
             error = prop_object_copyout_ioctl(pref, cmd, fooprops);
             break;
           }

         default:
             return (EPASSTHROUGH);
         }
         return (error);
     }

     The following (simplified) example demonstrates using
     prop_object_copyin() in a routine:

     int
     foocopyin(const struct plistref *pref))
     {
         prop_array_t array;
         int error;

         error = prop_object_copyin(pref, (prop_object_t *)&array);
         if (error)
                 return (error);
         ...
     }


ERRORS

     prop_object_copyin_ioctl() will fail if:

     [E2BIG]            The object being copied is larger than an arbitrarily
                        established limit (currently set to 128Kbytes).

     [EFAULT]           Bad address

     [EIO]              Input/output error

     [ENOMEM]           Cannot allocate memory

     prop_object_copyout_ioctl() will fail if:

     [EFAULT]           Bad address

     [ENOMEM]           Cannot allocate memory


SEE ALSO

     prop_array(3), prop_dictionary(3), prop_object(3), prop_send_ioctl(3),
     prop_send_syscall(3), proplib(3)


HISTORY

     The proplib property container object library first appeared in
     NetBSD 4.0.

NetBSD 10.99                    April 20, 2025                    NetBSD 10.99