1 files changed, 279 insertions, 4 deletions

diff --git a/cpukit/posix/src/shmopen.c b/cpukit/posix/src/shmopen.c
index abac3f4057..fec443abba 100644
--- a/cpukit/posix/src/shmopen.c
+++ b/cpukit/posix/src/shmopen.c
@@ -16,13 +16,288 @@
 
 #include <sys/mman.h>
 #include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+
+#include <rtems/libio_.h>
 #include <rtems/seterr.h>
 
+#include <rtems/posix/shmimpl.h>
+#include <rtems/score/wkspace.h>
+
+static const rtems_filesystem_file_handlers_r shm_handlers;
+
+static int shm_fstat(
+  const rtems_filesystem_location_info_t *loc,
+  struct stat *buf
+)
+{
+  POSIX_Shm_Control *shm = loc_to_shm( loc );
+
+  if ( shm == NULL )
+    rtems_set_errno_and_return_minus_one( EIO );
+
+  /* mandatory for shm objects */
+  buf->st_uid = shm->uid;
+  buf->st_gid = shm->gid;
+  buf->st_size = shm->shm_object.size;
+  buf->st_mode = shm->mode;
+
+  /* optional for shm objects */
+  buf->st_atime = shm->atime;
+  buf->st_mtime = shm->mtime;
+  buf->st_ctime = shm->ctime;
+
+  return 0;
+}
+
+/* read() is unspecified for shared memory objects */
+static ssize_t shm_read( rtems_libio_t *iop, void *buffer, size_t count )
+{
+  Thread_queue_Context queue_context;
+  ssize_t bytes_read;
+  POSIX_Shm_Control *shm = iop_to_shm( iop );
+
+  _Thread_queue_Context_initialize( &queue_context );
+  _POSIX_Shm_Acquire( shm, &queue_context );
+  bytes_read = (*shm->shm_object.ops->object_read)(
+      &shm->shm_object,
+      buffer,
+      count
+  );
+  _POSIX_Shm_Release( shm, &queue_context );
+
+  return bytes_read;
+}
+
+static int shm_ftruncate( rtems_libio_t *iop, off_t length )
+{
+  Thread_queue_Context queue_context;
+  int err;
+  POSIX_Shm_Control *shm = iop_to_shm( iop );
+
+  _Thread_queue_Context_initialize( &queue_context );
+  _POSIX_Shm_Acquire( shm, &queue_context );
+
+  err = (*shm->shm_object.ops->object_resize)( &shm->shm_object, length );
+
+  if ( err != 0 ) {
+    _POSIX_Shm_Release( shm, &queue_context );
+    rtems_set_errno_and_return_minus_one( err );
+  }
+
+  _POSIX_Shm_Update_mtime_ctime( shm );
+
+  _POSIX_Shm_Release( shm, &queue_context );
+  return 0;
+}
+
+static int shm_close( rtems_libio_t *iop )
+{
+  POSIX_Shm_Control *shm = iop_to_shm( iop );
+  Objects_Control       *obj;
+  ISR_lock_Context       lock_ctx;
+  int err;
+
+  _Objects_Allocator_lock();
+
+  --shm->reference_count;
+  if ( shm->reference_count == 0 ) {
+    /* TODO: need to make sure this counts mmaps too! */
+    if ( (*shm->shm_object.ops->object_delete)( &shm->shm_object ) != 0 ) {
+      err = EIO;
+    }
+    /* check if the object has been unlinked yet. */
+    obj = _Objects_Get( shm->Object.id, &lock_ctx, &_POSIX_Shm_Information );
+    if ( obj == NULL ) {
+      /* if it was unlinked, then it can be freed. */
+      _POSIX_Shm_Free( shm );
+    } else {
+      /* it will be freed when it is unlinked. */
+      _ISR_lock_ISR_enable( &lock_ctx );
+    }
+  }
+  iop->pathinfo.node_access = NULL;
+
+  _Objects_Allocator_unlock();
+
+  if ( err != 0 ) {
+    rtems_set_errno_and_return_minus_one( err );
+  }
+  return 0;
+}
+
+static inline POSIX_Shm_Control *shm_allocate(
+  const char *name_arg,
+  size_t name_len,
+  int oflag,
+  mode_t mode,
+  int *error
+)
+{
+  POSIX_Shm_Control *shm;
+  char *name;
+  struct timeval tv;
+
+  /* Reject any name without a leading slash. */
+  if ( name_arg[0] != '/' ) {
+    *error = EINVAL;
+    return NULL;
+  }
+
+  /* Only create the object if requested. */
+  if ( ( oflag & O_CREAT ) != O_CREAT ) {
+    *error = ENOENT;
+    return NULL;
+  }
+
+  name = _Workspace_String_duplicate( name_arg, name_len );
+  if ( name == NULL ) {
+    *error = ENOSPC;
+    return NULL;
+  }
+
+  shm = _POSIX_Shm_Allocate_unprotected();
+  if ( shm == NULL ) {
+    _Workspace_Free( name );
+    *error = ENFILE;
+    return NULL;
+  }
+
+  gettimeofday( &tv, 0 );
+
+  shm->reference_count = 1;
+  shm->shm_object.handle = NULL;
+  shm->shm_object.size = 0;
+  shm->shm_object.ops = &_POSIX_Shm_Object_operations;
+  shm->mode = mode & ~rtems_filesystem_umask;
+  shm->uid = geteuid();
+  shm->gid = getegid();
+  shm->atime = (time_t) tv.tv_sec;
+  shm->mtime = (time_t) tv.tv_sec;
+  shm->ctime = (time_t) tv.tv_sec;
+
+  _Objects_Open_string( &_POSIX_Shm_Information, &shm->Object, name );
+
+  return shm;
+}
+
+static inline bool shm_access_ok( POSIX_Shm_Control *shm, int oflag )
+{
+  int flags;
+  if ( oflag & O_RDONLY ) {
+    flags = RTEMS_FS_PERMS_READ;
+  } else {
+    flags = RTEMS_FS_PERMS_WRITE;
+  }
+  return rtems_filesystem_check_access( flags, shm->mode, shm->uid, shm->gid );
+}
+
+static inline int shm_check_oflag( int oflag )
+{
+  if ( ( oflag & O_ACCMODE ) != O_RDONLY && ( oflag & O_ACCMODE ) != O_RDWR ) {
+    rtems_set_errno_and_return_minus_one( EACCES );
+  }
+
+  if ( ( oflag & ~( O_RDONLY | O_RDWR | O_CREAT | O_EXCL | O_TRUNC ) ) != 0 ) {
+    rtems_set_errno_and_return_minus_one( EACCES );
+  }
+
+  if ( ( oflag & O_TRUNC ) != 0 && ( oflag & O_ACCMODE ) != O_RDWR ) {
+    rtems_set_errno_and_return_minus_one( EACCES );
+  }
+  return 0;
+}
+
 int shm_open( const char *name, int oflag, mode_t mode )
 {
-  (void) name;
-  (void) oflag;
-  (void) mode;
+  int err = 0;
+  int fd;
+  rtems_libio_t *iop;
+  POSIX_Shm_Control *shm;
+  size_t len;
+  Objects_Get_by_name_error obj_err;
+
+  if ( shm_check_oflag( oflag ) != 0 ) {
+    return -1;
+  }
+
+  iop = rtems_libio_allocate();
+  if ( iop == NULL ) {
+    rtems_set_errno_and_return_minus_one( EMFILE );
+  }
 
-  rtems_set_errno_and_return_minus_one( EINVAL );
+  _Objects_Allocator_lock();
+  shm = _POSIX_Shm_Get_by_name( name, &len, &obj_err );
+
+  if ( shm == NULL ) {
+    switch ( obj_err ) {
+      case OBJECTS_GET_BY_NAME_INVALID_NAME:
+        err = EINVAL;
+        break;
+
+      case OBJECTS_GET_BY_NAME_NAME_TOO_LONG:
+        err = ENAMETOOLONG;
+        break;
+
+      case OBJECTS_GET_BY_NAME_NO_OBJECT:
+      default:
+        shm = shm_allocate(name, len, oflag, mode, &err);
+        break;
+    }
+  } else { /* shm exists */
+    if ( ( oflag & ( O_EXCL | O_CREAT ) ) == ( O_EXCL | O_CREAT ) ) {
+      /* Request to create failed. */
+      err = EEXIST;
+    } else if ( !shm_access_ok( shm, oflag ) ) {
+      err = EACCES;
+    } else {
+      ++shm->reference_count;
+    }
+  }
+  _Objects_Allocator_unlock();
+  if ( err != 0 ) {
+    rtems_libio_free( iop );
+    rtems_set_errno_and_return_minus_one( err );
+  }
+
+  if ( oflag & O_TRUNC ) {
+    err = shm_ftruncate( iop, 0 );
+    (void) err; /* ignore truncate error */
+  }
+
+  fd = rtems_libio_iop_to_descriptor( iop );
+  iop->flags |= LIBIO_FLAGS_CLOSE_ON_EXEC;
+  if ( oflag & O_RDONLY ) {
+    iop->flags |= LIBIO_FLAGS_READ;
+  } else {
+    iop->flags |= LIBIO_FLAGS_READ_WRITE;
+  }
+  iop->data0 = fd;
+  iop->data1 = shm;
+  iop->pathinfo.node_access = shm;
+  iop->pathinfo.handlers = &shm_handlers;
+  iop->pathinfo.mt_entry = &rtems_filesystem_null_mt_entry;
+  rtems_filesystem_location_add_to_mt_entry( &iop->pathinfo );
+
+  return fd;
 }
+
+static const rtems_filesystem_file_handlers_r shm_handlers = {
+  .open_h = rtems_filesystem_default_open,
+  .close_h = shm_close,
+  .read_h = shm_read,
+  .write_h = rtems_filesystem_default_write,
+  .ioctl_h = rtems_filesystem_default_ioctl,
+  .lseek_h = rtems_filesystem_default_lseek,
+  .fstat_h = shm_fstat,
+  .ftruncate_h = shm_ftruncate,
+  .fsync_h = rtems_filesystem_default_fsync_or_fdatasync,
+  .fdatasync_h = rtems_filesystem_default_fsync_or_fdatasync,
+  .fcntl_h = rtems_filesystem_default_fcntl,
+  .kqfilter_h = rtems_filesystem_default_kqfilter,
+  .poll_h = rtems_filesystem_default_poll,
+  .readv_h = rtems_filesystem_default_readv,
+  .writev_h = rtems_filesystem_default_writev
+};