sysdeps/mach/hurd/ioctl.c

   1 /* Copyright (C) 1992,93,94,95,96,97,99,2000,2002,2005
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <sys/ioctl.h>
  22 #include <hurd.h>
  23 #include <hurd/fd.h>
  24 #include <hurd/signal.h>
  25 #include <stdarg.h>
  26 #include <mach/notify.h>
  27 #include <assert.h>
  28 #include <string.h>
  29 #include <stdint.h>
  30 #include <hurd/ioctl.h>
  31 #include <mach/mig_support.h>
  32
  33 #include <hurd/ioctls.defs>
  34
  35 #define typesize(type)  (1 << (type))
  36
  37
  38 /* Perform the I/O control operation specified by REQUEST on FD.
  39    The actual type and use of ARG and the return value depend on REQUEST.  */
  40 int
  41 __ioctl (int fd, unsigned long int request, ...)
  42 {
  43 #ifdef MACH_MSG_TYPE_CHAR
  44   /* Map individual type fields to Mach IPC types.  */
  45   static const int mach_types[] =
  46     { MACH_MSG_TYPE_CHAR, MACH_MSG_TYPE_INTEGER_16, MACH_MSG_TYPE_INTEGER_32,
  47       MACH_MSG_TYPE_INTEGER_64 };
  48 #define io2mach_type(count, type) \
  49   ((mach_msg_type_t) { mach_types[type], typesize (type) * 8, count, 1, 0, 0 })
  50 #endif
  51
  52   /* Extract the type information encoded in the request.  */
  53   unsigned int type = _IOC_TYPE (request);
  54
  55   /* Message buffer.  */
  56 #define msg_align(x) \
  57   (((x) + sizeof (mach_msg_type_t) - 1) & ~(sizeof (mach_msg_type_t) - 1))
  58   struct
  59   {
  60 #ifdef MACH_MSG_TYPE_BIT
  61     union
  62     {
  63       mig_reply_header_t header;
  64       struct
  65       {
  66         mach_msg_header_t       Head;
  67         int                     RetCodeType;
  68         kern_return_t           RetCode;
  69       } header_typecheck;
  70     };
  71     char data[3 * sizeof (mach_msg_type_t) +
  72              msg_align (_IOT_COUNT0 (type) * typesize (_IOT_TYPE0 (type))) +
  73              msg_align (_IOT_COUNT1 (type) * typesize (_IOT_TYPE1 (type))) +
  74              _IOT_COUNT2 (type) * typesize (_IOT_TYPE2 (type))];
  75 #else  /* Untyped Mach IPC format.  */
  76     mig_reply_error_t header;
  77     char data[_IOT_COUNT0 (type) * typesize (_IOT_TYPE0 (type)) +
  78              _IOT_COUNT1 (type) * typesize (_IOT_TYPE1 (type)) +
  79              _IOT_COUNT2 (type) * typesize (_IOT_TYPE2 (type))];
  80     mach_msg_trailer_t trailer;
  81 #endif
  82   } msg;
  83   mach_msg_header_t *const m = &msg.header.Head;
  84   mach_msg_id_t msgid;
  85   unsigned int reply_size;
  86 #ifdef MACH_MSG_TYPE_BIT
  87   mach_msg_type_t *t;
  88 #else
  89   void *p;
  90 #endif
  91
  92   void *arg;
  93
  94   error_t err;
  95
  96   /* Send the RPC already packed up in MSG to IOPORT
  97      and decode the return value.  */
  98   error_t send_rpc (io_t ioport)
  99     {
 100       error_t err;
 101 #ifdef MACH_MSG_TYPE_BIT
 102       mach_msg_type_t *t = &msg.header.RetCodeType;
 103 #else
 104       void *p = &msg.header.RetCode;
 105 #endif
 106
 107       /* Marshal the request arguments into the message buffer.
 108          We must redo this work each time we retry the RPC after a SIGTTOU,
 109          because the reply message containing the EBACKGROUND error code
 110          clobbers the same message buffer also used for the request.  */
 111
 112       if (_IOC_INOUT (request) & IOC_IN)
 113         {
 114           /* We don't want to advance ARG since it will be used to copy out
 115              too if IOC_OUT is also set.  */
 116           void *argptr = arg;
 117
 118           /* Pack an argument into the message buffer.  */
 119           void in (unsigned int count, enum __ioctl_datum type)
 120             {
 121               if (count > 0)
 122                 {
 123                   const size_t len = count * typesize ((unsigned int) type);
 124 #ifdef MACH_MSG_TYPE_BIT
 125                   void *p = &t[1];
 126                   *t = io2mach_type (count, type);
 127                   p = __mempcpy (p, argptr, len);
 128                   p = (void *) (((uintptr_t) p + sizeof (*t) - 1)
 129                                 & ~(sizeof (*t) - 1));
 130                   t = p;
 131 #else
 132                   p = __mempcpy (p, argptr, len);
 133 #endif
 134                   argptr += len;
 135                 }
 136             }
 137
 138           /* Pack the argument data.  */
 139           in (_IOT_COUNT0 (type), _IOT_TYPE0 (type));
 140           in (_IOT_COUNT1 (type), _IOT_TYPE1 (type));
 141           in (_IOT_COUNT2 (type), _IOT_TYPE2 (type));
 142         }
 143       else if (_IOC_INOUT (request) == IOC_VOID)
 144         {
 145           /* The RPC takes a single integer_t argument.
 146              Rather than pointing to the value, ARG is the value itself.  */
 147 #ifdef MACH_MSG_TYPE_BIT
 148           *t++ = io2mach_type (1, _IOTS (integer_t));
 149           *(integer_t *) t = (integer_t) arg;
 150           t = (void *) t + sizeof (integer_t);
 151 #else
 152           *(integer_t *) p = (integer_t) arg;
 153           p = (void *) p + sizeof (integer_t);
 154 #endif
 155         }
 156
 157       memset (m, 0, sizeof *m); /* Clear unused fields.  */
 158       m->msgh_size = (
 159 #ifdef MACH_MSG_TYPE_BIT
 160                       (char *) t
 161 #else
 162                       (char *) p
 163 #endif
 164                       - (char *) &msg);
 165       m->msgh_remote_port = ioport;
 166       m->msgh_local_port = __mig_get_reply_port ();
 167       m->msgh_id = msgid;
 168       m->msgh_bits = MACH_MSGH_BITS (MACH_MSG_TYPE_COPY_SEND,
 169                                      MACH_MSG_TYPE_MAKE_SEND_ONCE);
 170       err = _hurd_intr_rpc_mach_msg (m, MACH_SEND_MSG|MACH_RCV_MSG,
 171                                      m->msgh_size, sizeof (msg),
 172                                      m->msgh_local_port,
 173                                      MACH_MSG_TIMEOUT_NONE,
 174                                      MACH_PORT_NULL);
 175       switch (err)
 176         {
 177         case MACH_MSG_SUCCESS:
 178           break;
 179         case MACH_SEND_INVALID_REPLY:
 180         case MACH_RCV_INVALID_NAME:
 181           __mig_dealloc_reply_port (m->msgh_local_port);
 182         default:
 183           return err;
 184         }
 185
 186       if ((m->msgh_bits & MACH_MSGH_BITS_COMPLEX))
 187         {
 188           /* Allow no ports or VM.  */
 189           __mach_msg_destroy (m);
 190           /* Want to return a different error below for a different msgid.  */
 191           if (m->msgh_id == msgid + 100)
 192             return MIG_TYPE_ERROR;
 193         }
 194
 195       if (m->msgh_id != msgid + 100)
 196         return (m->msgh_id == MACH_NOTIFY_SEND_ONCE ?
 197                 MIG_SERVER_DIED : MIG_REPLY_MISMATCH);
 198
 199       if (m->msgh_size != reply_size &&
 200           m->msgh_size != sizeof msg.header)
 201         return MIG_TYPE_ERROR;
 202
 203 #ifdef MACH_MSG_TYPE_BIT
 204       if (msg.header_typecheck.RetCodeType !=
 205           ((union { mach_msg_type_t t; int i; })
 206            { t: io2mach_type (1, _IOTS (msg.header.RetCode)) }).i)
 207         return MIG_TYPE_ERROR;
 208 #endif
 209       return msg.header.RetCode;
 210     }
 211
 212   va_list ap;
 213
 214   va_start (ap, request);
 215   arg = va_arg (ap, void *);
 216   va_end (ap);
 217
 218   {
 219     /* Check for a registered handler for REQUEST.  */
 220     ioctl_handler_t handler = _hurd_lookup_ioctl_handler (request);
 221     if (handler)
 222       {
 223         /* This handler groks REQUEST.  Se lo puntamonos.  */
 224         int save = errno;
 225         int result = (*handler) (fd, request, arg);
 226         if (result != -1 || errno != ENOTTY)
 227           return result;
 228
 229         /* The handler doesn't really grok this one.
 230            Try the normal RPC translation.  */
 231         errno = save;
 232       }
 233   }
 234
 235   /* Compute the Mach message ID for the RPC from the group and command
 236      parts of the ioctl request.  */
 237   msgid = IOC_MSGID (request);
 238
 239   /* Compute the expected size of the reply.  There is a standard header
 240      consisting of the message header and the reply code.  Then, for out
 241      and in/out ioctls, there come the data with their type headers.  */
 242   reply_size = sizeof msg.header;
 243
 244   if (_IOC_INOUT (request) & IOC_OUT)
 245     {
 246       inline void figure_reply (unsigned int count, enum __ioctl_datum type)
 247         {
 248           if (count > 0)
 249             {
 250 #ifdef MACH_MSG_TYPE_BIT
 251               /* Add the size of the type and data.  */
 252               reply_size += sizeof (mach_msg_type_t) + typesize (type) * count;
 253               /* Align it to word size.  */
 254               reply_size += sizeof (mach_msg_type_t) - 1;
 255               reply_size &= ~(sizeof (mach_msg_type_t) - 1);
 256 #else
 257               reply_size += typesize (type) * count;
 258 #endif
 259             }
 260         }
 261       figure_reply (_IOT_COUNT0 (type), _IOT_TYPE0 (type));
 262       figure_reply (_IOT_COUNT1 (type), _IOT_TYPE1 (type));
 263       figure_reply (_IOT_COUNT2 (type), _IOT_TYPE2 (type));
 264     }
 265
 266   /* Marshal the arguments into the request message and make the RPC.
 267      This wrapper function handles EBACKGROUND returns, turning them
 268      into either SIGTTOU or EIO.  */
 269   err = HURD_DPORT_USE (fd, _hurd_ctty_output (port, ctty, send_rpc));
 270
 271 #ifdef MACH_MSG_TYPE_BIT
 272   t = (mach_msg_type_t *) msg.data;
 273 #else
 274   p = (void *) msg.data;
 275 #endif
 276   switch (err)
 277     {
 278       /* Unpack the message buffer into the argument location.  */
 279       int out (unsigned int count, unsigned int type,
 280                void *store, void **update)
 281         {
 282           if (count > 0)
 283             {
 284               const size_t len = count * typesize (type);
 285 #ifdef MACH_MSG_TYPE_BIT
 286               union { mach_msg_type_t t; int i; } ipctype;
 287               ipctype.t = io2mach_type (count, type);
 288               if (*(int *) t != ipctype.i)
 289                 return 1;
 290               ++t;
 291               memcpy (store, t, len);
 292               if (update != NULL)
 293                 *update += len;
 294               t = (void *) (((uintptr_t) t + len + sizeof (*t) - 1)
 295                             & ~(sizeof (*t) - 1));
 296 #else
 297               memcpy (store, p, len);
 298               p += len;
 299               if (update != NULL)
 300                 *update += len;
 301 #endif
 302             }
 303           return 0;
 304         }
 305
 306     case 0:
 307       if (m->msgh_size != reply_size ||
 308           ((_IOC_INOUT (request) & IOC_OUT) &&
 309            (out (_IOT_COUNT0 (type), _IOT_TYPE0 (type), arg, &arg) ||
 310             out (_IOT_COUNT1 (type), _IOT_TYPE1 (type), arg, &arg) ||
 311             out (_IOT_COUNT2 (type), _IOT_TYPE2 (type), arg, &arg))))
 312         return __hurd_fail (MIG_TYPE_ERROR);
 313       return 0;
 314
 315     case MIG_BAD_ID:
 316     case EOPNOTSUPP:
 317       /* The server didn't understand the RPC.  */
 318       err = ENOTTY;
 319     default:
 320       return __hurd_fail (err);
 321     }
 322 }
 323
 324 weak_alias (__ioctl, ioctl)