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