native_client_sdk/src/libraries/nacl_io/html5fs/html5_fs_node.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "nacl_io/html5fs/html5_fs_node.h"
   6
   7 #include <errno.h>
   8 #include <fcntl.h>
   9 #include <ppapi/c/pp_completion_callback.h>
  10 #include <ppapi/c/pp_directory_entry.h>
  11 #include <ppapi/c/pp_errors.h>
  12 #include <ppapi/c/pp_file_info.h>
  13 #include <ppapi/c/ppb_file_io.h>
  14 #include <string.h>
  15 #include <vector>
  16
  17 #include "nacl_io/filesystem.h"
  18 #include "nacl_io/getdents_helper.h"
  19 #include "nacl_io/html5fs/html5_fs.h"
  20 #include "nacl_io/kernel_handle.h"
  21 #include "nacl_io/osdirent.h"
  22 #include "nacl_io/pepper_interface.h"
  23 #include "sdk_util/auto_lock.h"
  24
  25 namespace nacl_io {
  26
  27 namespace {
  28
  29 struct OutputBuffer {
  30   void* data;
  31   int element_count;
  32 };
  33
  34 void* GetOutputBuffer(void* user_data, uint32_t count, uint32_t size) {
  35   OutputBuffer* output = static_cast<OutputBuffer*>(user_data);
  36   output->element_count = count;
  37   if (count) {
  38     output->data = malloc(count * size);
  39     if (!output->data)
  40       output->element_count = 0;
  41   } else {
  42     output->data = NULL;
  43   }
  44   return output->data;
  45 }
  46
  47 int32_t OpenFlagsToPPAPIOpenFlags(int open_flags) {
  48   int32_t ppapi_flags = 0;
  49
  50   switch (open_flags & 3) {
  51     default:
  52     case O_RDONLY:
  53       ppapi_flags = PP_FILEOPENFLAG_READ;
  54       break;
  55     case O_WRONLY:
  56       ppapi_flags = PP_FILEOPENFLAG_WRITE;
  57       break;
  58     case O_RDWR:
  59       ppapi_flags = PP_FILEOPENFLAG_READ | PP_FILEOPENFLAG_WRITE;
  60       break;
  61   }
  62
  63   if (open_flags & O_CREAT)
  64     ppapi_flags |= PP_FILEOPENFLAG_CREATE;
  65   if (open_flags & O_TRUNC)
  66     ppapi_flags |= PP_FILEOPENFLAG_TRUNCATE;
  67   if (open_flags & O_EXCL)
  68     ppapi_flags |= PP_FILEOPENFLAG_EXCLUSIVE;
  69
  70   return ppapi_flags;
  71 }
  72
  73 }  // namespace
  74
  75 Error Html5FsNode::FSync() {
  76   // Cannot call Flush on a directory; simply do nothing.
  77   if (IsaDir())
  78     return 0;
  79
  80   int32_t result =
  81       file_io_iface_->Flush(fileio_resource_, PP_BlockUntilComplete());
  82   if (result != PP_OK)
  83     return PPERROR_TO_ERRNO(result);
  84   return 0;
  85 }
  86
  87 Error Html5FsNode::GetDents(size_t offs,
  88                             struct dirent* pdir,
  89                             size_t size,
  90                             int* out_bytes) {
  91   *out_bytes = 0;
  92
  93   // If this is not a directory, fail
  94   if (!IsaDir())
  95     return ENOTDIR;
  96
  97   // TODO(binji): Better handling of ino numbers.
  98   const ino_t kCurDirIno = -1;
  99   const ino_t kParentDirIno = -2;
 100   GetDentsHelper helper(kCurDirIno, kParentDirIno);
 101
 102   OutputBuffer output_buf = {NULL, 0};
 103   PP_ArrayOutput output = {&GetOutputBuffer, &output_buf};
 104   int32_t result = file_ref_iface_->ReadDirectoryEntries(
 105       fileref_resource_, output, PP_BlockUntilComplete());
 106   if (result != PP_OK)
 107     return PPERROR_TO_ERRNO(result);
 108
 109   PP_DirectoryEntry* entries = static_cast<PP_DirectoryEntry*>(output_buf.data);
 110
 111   for (int i = 0; i < output_buf.element_count; ++i) {
 112     PP_Var file_name_var = file_ref_iface_->GetName(entries[i].file_ref);
 113
 114     // Release the file reference.
 115     filesystem_->ppapi()->ReleaseResource(entries[i].file_ref);
 116
 117     if (file_name_var.type != PP_VARTYPE_STRING)
 118       continue;
 119
 120     uint32_t file_name_length;
 121     const char* file_name =
 122         var_iface_->VarToUtf8(file_name_var, &file_name_length);
 123
 124     if (file_name) {
 125       file_name_length =
 126           std::min(static_cast<size_t>(file_name_length),
 127                    MEMBER_SIZE(dirent, d_name) - 1);  // -1 for NULL.
 128
 129       // The INO is based on the running hash of fully qualified path, so
 130       // a childs INO must be the parent directories hash, plus '/', plus
 131       // the filename.
 132       ino_t child_ino = Html5Fs::HashPathSegment(stat_.st_ino, file_name,
 133                                                  file_name_length);
 134
 135       helper.AddDirent(child_ino, file_name, file_name_length);
 136     }
 137
 138     var_iface_->Release(file_name_var);
 139   }
 140
 141   // Release the output buffer.
 142   free(output_buf.data);
 143
 144   return helper.GetDents(offs, pdir, size, out_bytes);
 145 }
 146
 147 Error Html5FsNode::GetStat(struct stat* stat) {
 148   AUTO_LOCK(node_lock_);
 149
 150   PP_FileInfo info;
 151   int32_t result =
 152       file_ref_iface_->Query(fileref_resource_, &info, PP_BlockUntilComplete());
 153   if (result != PP_OK)
 154     return PPERROR_TO_ERRNO(result);
 155
 156   // Fill in known info here.
 157   memcpy(stat, &stat_, sizeof(stat_));
 158
 159   // Fill in the additional info from ppapi.
 160   switch (info.type) {
 161     case PP_FILETYPE_REGULAR:
 162       stat->st_mode |= S_IFREG;
 163       break;
 164     case PP_FILETYPE_DIRECTORY:
 165       stat->st_mode |= S_IFDIR;
 166       break;
 167     case PP_FILETYPE_OTHER:
 168     default:
 169       break;
 170   }
 171   stat->st_size = static_cast<off_t>(info.size);
 172   stat->st_atime = info.last_access_time;
 173   stat->st_mtime = info.last_modified_time;
 174   stat->st_ctime = info.creation_time;
 175
 176   return 0;
 177 }
 178
 179 Error Html5FsNode::Read(const HandleAttr& attr,
 180                         void* buf,
 181                         size_t count,
 182                         int* out_bytes) {
 183   *out_bytes = 0;
 184
 185   if (IsaDir())
 186     return EISDIR;
 187
 188   int32_t result = file_io_iface_->Read(fileio_resource_,
 189                                         attr.offs,
 190                                         static_cast<char*>(buf),
 191                                         static_cast<int32_t>(count),
 192                                         PP_BlockUntilComplete());
 193   if (result < 0)
 194     return PPERROR_TO_ERRNO(result);
 195
 196   *out_bytes = result;
 197   return 0;
 198 }
 199
 200 Error Html5FsNode::FTruncate(off_t size) {
 201   if (IsaDir())
 202     return EISDIR;
 203
 204   int32_t result = file_io_iface_->SetLength(
 205       fileio_resource_, size, PP_BlockUntilComplete());
 206   if (result != PP_OK)
 207     return PPERROR_TO_ERRNO(result);
 208   return 0;
 209 }
 210
 211 Error Html5FsNode::Write(const HandleAttr& attr,
 212                          const void* buf,
 213                          size_t count,
 214                          int* out_bytes) {
 215   *out_bytes = 0;
 216
 217   if (IsaDir())
 218     return EISDIR;
 219
 220   int32_t result = file_io_iface_->Write(fileio_resource_,
 221                                          attr.offs,
 222                                          static_cast<const char*>(buf),
 223                                          static_cast<int32_t>(count),
 224                                          PP_BlockUntilComplete());
 225   if (result < 0)
 226     return PPERROR_TO_ERRNO(result);
 227
 228   *out_bytes = result;
 229   return 0;
 230 }
 231
 232 int Html5FsNode::GetType() {
 233   return fileio_resource_ ? S_IFREG : S_IFDIR;
 234 }
 235
 236 Error Html5FsNode::GetSize(off_t* out_size) {
 237   *out_size = 0;
 238
 239   if (IsaDir())
 240     return 0;
 241
 242   AUTO_LOCK(node_lock_);
 243
 244   PP_FileInfo info;
 245   int32_t result =
 246       file_io_iface_->Query(fileio_resource_, &info, PP_BlockUntilComplete());
 247   if (result != PP_OK)
 248     return PPERROR_TO_ERRNO(result);
 249
 250   *out_size = info.size;
 251   return 0;
 252 }
 253
 254 Html5FsNode::Html5FsNode(Filesystem* filesystem, PP_Resource fileref_resource)
 255     : Node(filesystem),
 256       fileref_resource_(fileref_resource),
 257       fileio_resource_(0) {
 258 }
 259
 260 Error Html5FsNode::Init(int open_flags) {
 261   Error error = Node::Init(open_flags);
 262   if (error)
 263     return error;
 264
 265   file_io_iface_ = filesystem_->ppapi()->GetFileIoInterface();
 266   file_ref_iface_ = filesystem_->ppapi()->GetFileRefInterface();
 267   var_iface_ = filesystem_->ppapi()->GetVarInterface();
 268
 269   if (!(file_io_iface_ && file_ref_iface_ && var_iface_)) {
 270     LOG_ERROR("Got NULL interface(s): %s%s%s",
 271               file_ref_iface_ ? "" : "FileRef",
 272               file_io_iface_ ? "" : "FileIo ",
 273               var_iface_ ? "" : "Var ");
 274     return EIO;
 275   }
 276
 277   // Set all files and directories to RWX.
 278   SetMode(S_IWALL | S_IRALL | S_IXALL);
 279
 280   // First query the FileRef to see if it is a file or directory.
 281   PP_FileInfo file_info;
 282   int32_t query_result = file_ref_iface_->Query(
 283       fileref_resource_, &file_info, PP_BlockUntilComplete());
 284   // If this is a directory, do not get a FileIO.
 285   if (query_result == PP_OK && file_info.type == PP_FILETYPE_DIRECTORY) {
 286     return 0;
 287   }
 288
 289   fileio_resource_ =
 290       file_io_iface_->Create(filesystem_->ppapi()->GetInstance());
 291   if (!fileio_resource_) {
 292     LOG_ERROR("Couldn't create FileIo resource.");
 293     return EIO;
 294   }
 295
 296   int32_t open_result =
 297       file_io_iface_->Open(fileio_resource_,
 298                            fileref_resource_,
 299                            OpenFlagsToPPAPIOpenFlags(open_flags),
 300                            PP_BlockUntilComplete());
 301   if (open_result != PP_OK)
 302     return PPERROR_TO_ERRNO(open_result);
 303   return 0;
 304 }
 305
 306 void Html5FsNode::Destroy() {
 307   FSync();
 308
 309   if (fileio_resource_) {
 310     file_io_iface_->Close(fileio_resource_);
 311     filesystem_->ppapi()->ReleaseResource(fileio_resource_);
 312   }
 313
 314   filesystem_->ppapi()->ReleaseResource(fileref_resource_);
 315   fileio_resource_ = 0;
 316   fileref_resource_ = 0;
 317   Node::Destroy();
 318 }
 319
 320 Error Html5FsNode::Fchmod(mode_t mode) {
 321   // html5fs does not support any kinds of permissions or mode bits.
 322   return 0;
 323 }
 324
 325 }  // namespace nacl_io