sysdeps/mach/hurd/ioctl.c

   1 /* Copyright (C) 1992, 93, 94, 95, 96, 97, 99 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <errno.h>
  20 #include <sys/ioctl.h>
  21 #include <hurd.h>
  22 #include <hurd/fd.h>
  23 #include <hurd/signal.h>
  24 #include <stdarg.h>
  25 #include <mach/notify.h>
  26 #include <assert.h>
  27 #include <string.h>
  28 #include <hurd/ioctl.h>
  29 #include <mach/mig_support.h>
  30
  31 #include <hurd/ioctls.defs>
  32
  33 #define typesize(type)  (1 << (type))
  34
  35
  36 /* Perform the I/O control operation specified by REQUEST on FD.
  37    The actual type and use of ARG and the return value depend on REQUEST.  */
  38 int
  39 __ioctl (int fd, unsigned long int request, ...)
  40 {
  41   /* Map individual type fields to Mach IPC types.  */
  42   static const int mach_types[] =
  43     { MACH_MSG_TYPE_CHAR, MACH_MSG_TYPE_INTEGER_16, MACH_MSG_TYPE_INTEGER_32,
  44       MACH_MSG_TYPE_INTEGER_64 };
  45 #define io2mach_type(count, type) \
  46   ((mach_msg_type_t) { mach_types[type], typesize (type) * 8, count, 1, 0, 0 })
  47
  48   /* Extract the type information encoded in the request.  */
  49   unsigned int type = _IOC_TYPE (request);
  50
  51   /* Message buffer.  */
  52 #define msg_align(x) \
  53   (((x) + sizeof (mach_msg_type_t) - 1) & ~(sizeof (mach_msg_type_t) - 1))
  54   struct
  55     {
  56       mig_reply_header_t header;
  57       char data[3 * sizeof (mach_msg_type_t) +
  58                 msg_align (_IOT_COUNT0 (type) * typesize (_IOT_TYPE0 (type))) +
  59                 msg_align (_IOT_COUNT1 (type) * typesize (_IOT_TYPE1 (type))) +
  60                 _IOT_COUNT2 (type) * typesize (_IOT_TYPE2 (type))];
  61     } msg;
  62   mach_msg_header_t *const m = &msg.header.Head;
  63   mach_msg_type_t *t;
  64   mach_msg_id_t msgid;
  65   unsigned int reply_size;
  66
  67   void *arg;
  68
  69   error_t err;
  70
  71   /* Send the RPC already packed up in MSG to IOPORT
  72      and decode the return value.  */
  73   error_t send_rpc (io_t ioport)
  74     {
  75       error_t err;
  76       mach_msg_type_t *t = &msg.header.RetCodeType;
  77
  78       /* Marshal the request arguments into the message buffer.
  79          We must redo this work each time we retry the RPC after a SIGTTOU,
  80          because the reply message containing the EBACKGROUND error code
  81          clobbers the same message buffer also used for the request.  */
  82
  83       if (_IOC_INOUT (request) & IOC_IN)
  84         {
  85           /* Pack an argument into the message buffer.  */
  86           void in (unsigned int count, enum __ioctl_datum type)
  87             {
  88               if (count > 0)
  89                 {
  90                   void *p = &t[1];
  91                   const size_t len = count * typesize ((unsigned int) type);
  92                   *t = io2mach_type (count, type);
  93                   memcpy (p, arg, len);
  94                   arg += len;
  95                   p += len;
  96                   p = (void *) (((unsigned long int) p + sizeof (*t) - 1)
  97                                 & ~(sizeof (*t) - 1));
  98                   t = p;
  99                 }
 100             }
 101
 102           /* Pack the argument data.  */
 103           in (_IOT_COUNT0 (type), _IOT_TYPE0 (type));
 104           in (_IOT_COUNT1 (type), _IOT_TYPE1 (type));
 105           in (_IOT_COUNT2 (type), _IOT_TYPE2 (type));
 106         }
 107       else if (_IOC_INOUT (request) == IOC_VOID)
 108         {
 109           /* The RPC takes a single integer_t argument.
 110              Rather than pointing to the value, ARG is the value itself.  */
 111           *t++ = io2mach_type (1, _IOTS (int));
 112           *((int *) t)++ = (int) arg;
 113         }
 114
 115       m->msgh_size = (char *) t - (char *) &msg;
 116       m->msgh_remote_port = ioport;
 117       m->msgh_local_port = __mig_get_reply_port ();
 118       m->msgh_seqno = 0;
 119       m->msgh_id = msgid;
 120       m->msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND,
 121                                      MACH_MSG_TYPE_MAKE_SEND_ONCE);
 122       err = _hurd_intr_rpc_mach_msg (m, MACH_SEND_MSG|MACH_RCV_MSG,
 123                                      m->msgh_size, sizeof (msg),
 124                                      m->msgh_local_port,
 125                                      MACH_MSG_TIMEOUT_NONE,
 126                                      MACH_PORT_NULL);
 127       switch (err)
 128         {
 129         case MACH_MSG_SUCCESS:
 130           break;
 131         case MACH_SEND_INVALID_REPLY:
 132         case MACH_RCV_INVALID_NAME:
 133           __mig_dealloc_reply_port (m->msgh_local_port);
 134         default:
 135           return err;
 136         }
 137
 138       if ((m->msgh_bits & MACH_MSGH_BITS_COMPLEX))
 139         {
 140           /* Allow no ports or VM.  */
 141           __mach_msg_destroy (m);
 142           /* Want to return a different error below for a different msgid.  */
 143           if (m->msgh_id == msgid + 100)
 144             return MIG_TYPE_ERROR;
 145         }
 146
 147       if (m->msgh_id != msgid + 100)
 148         return (m->msgh_id == MACH_NOTIFY_SEND_ONCE ?
 149                 MIG_SERVER_DIED : MIG_REPLY_MISMATCH);
 150
 151       if (m->msgh_size != reply_size &&
 152           m->msgh_size != sizeof (mig_reply_header_t))
 153         return MIG_TYPE_ERROR;
 154
 155       if (*(int *) &msg.header.RetCodeType !=
 156           ((union { mach_msg_type_t t; int i; })
 157            { t: io2mach_type (1, _IOTS (sizeof msg.header.RetCode)) }).i)
 158         return MIG_TYPE_ERROR;
 159       return msg.header.RetCode;
 160     }
 161
 162   va_list ap;
 163
 164   va_start (ap, request);
 165   arg = va_arg (ap, void *);
 166   va_end (ap);
 167
 168   {
 169     /* Check for a registered handler for REQUEST.  */
 170     ioctl_handler_t handler = _hurd_lookup_ioctl_handler (request);
 171     if (handler)
 172       {
 173         /* This handler groks REQUEST.  Se lo puntamonos.  */
 174         int save = errno;
 175         int result = (*handler) (fd, request, arg);
 176         if (result != -1 || errno != ENOTTY)
 177           return result;
 178
 179         /* The handler doesn't really grok this one.
 180            Try the normal RPC translation.  */
 181         errno = save;
 182       }
 183   }
 184
 185   /* Compute the Mach message ID for the RPC from the group and command
 186      parts of the ioctl request.  */
 187   msgid = IOC_MSGID (request);
 188
 189   /* Compute the expected size of the reply.  There is a standard header
 190      consisting of the message header and the reply code.  Then, for out
 191      and in/out ioctls, there come the data with their type headers.  */
 192   reply_size = sizeof (mig_reply_header_t);
 193
 194   if (_IOC_INOUT (request) & IOC_OUT)
 195     {
 196       inline void figure_reply (unsigned int count, enum __ioctl_datum type)
 197         {
 198           if (count > 0)
 199             {
 200               /* Add the size of the type and data.  */
 201               reply_size += sizeof (mach_msg_type_t) + typesize (type) * count;
 202               /* Align it to word size.  */
 203               reply_size += sizeof (mach_msg_type_t) - 1;
 204               reply_size &= ~(sizeof (mach_msg_type_t) - 1);
 205             }
 206         }
 207       figure_reply (_IOT_COUNT0 (type), _IOT_TYPE0 (type));
 208       figure_reply (_IOT_COUNT1 (type), _IOT_TYPE1 (type));
 209       figure_reply (_IOT_COUNT2 (type), _IOT_TYPE2 (type));
 210     }
 211
 212   /* Marshal the arguments into the request message and make the RPC.
 213      This wrapper function handles EBACKGROUND returns, turning them
 214      into either SIGTTOU or EIO.  */
 215   err = HURD_DPORT_USE (fd, _hurd_ctty_output (port, ctty, send_rpc));
 216
 217   t = (mach_msg_type_t *) msg.data;
 218   switch (err)
 219     {
 220       /* Unpack the message buffer into the argument location.  */
 221       int out (unsigned int count, unsigned int type,
 222                void *store, void **update)
 223         {
 224           if (count > 0)
 225             {
 226               const size_t len = count * typesize (type);
 227               union { mach_msg_type_t t; int i; } ipctype;
 228               ipctype.t = io2mach_type (count, type);
 229               if (*(int *) t != ipctype.i)
 230                 return 1;
 231               ++t;
 232               memcpy (store, t, len);
 233               if (update != NULL)
 234                 *update += len;
 235               t = (void *) (((unsigned long int) t + len + sizeof (*t) - 1)
 236                             & ~(sizeof (*t) - 1));
 237             }
 238           return 0;
 239         }
 240
 241     case 0:
 242       if (m->msgh_size != reply_size ||
 243           ((_IOC_INOUT (request) & IOC_OUT) &&
 244            (out (_IOT_COUNT0 (type), _IOT_TYPE0 (type), arg, &arg) ||
 245             out (_IOT_COUNT1 (type), _IOT_TYPE1 (type), arg, &arg) ||
 246             out (_IOT_COUNT2 (type), _IOT_TYPE2 (type), arg, &arg))))
 247         return __hurd_fail (MIG_TYPE_ERROR);
 248       return 0;
 249
 250     case MIG_BAD_ID:
 251     case EOPNOTSUPP:
 252       /* The server didn't understand the RPC.  */
 253       err = ENOTTY;
 254     default:
 255       return __hurd_fail (err);
 256     }
 257 }
 258
 259 weak_alias (__ioctl, ioctl)