652 lines
15 KiB
C++
652 lines
15 KiB
C++
/*
|
|
* \brief TAR file system
|
|
* \author Norman Feske
|
|
* \date 2011-02-17
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2011-2013 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
#ifndef _NOUX__TAR_FILE_SYSTEM_H_
|
|
#define _NOUX__TAR_FILE_SYSTEM_H_
|
|
|
|
/* Genode includes */
|
|
#include <base/printf.h>
|
|
#include <base/lock.h>
|
|
#include <rom_session/connection.h>
|
|
#include <dataspace/client.h>
|
|
|
|
/* Noux includes */
|
|
#include <noux_session/sysio.h>
|
|
#include <file_system.h>
|
|
#include <vfs_handle.h>
|
|
|
|
namespace Noux {
|
|
|
|
class Tar_file_system : public File_system
|
|
{
|
|
enum { verbose = false };
|
|
|
|
Lock _lock;
|
|
|
|
struct Rom_name
|
|
{
|
|
enum { ROM_NAME_MAX_LEN = 64 };
|
|
char name[ROM_NAME_MAX_LEN];
|
|
|
|
Rom_name(Xml_node config) {
|
|
config.attribute("name").value(name, sizeof(name));
|
|
}
|
|
} _rom_name;
|
|
|
|
Rom_connection _rom;
|
|
|
|
char *_tar_base;
|
|
size_t _tar_size;
|
|
|
|
class Record
|
|
{
|
|
private:
|
|
|
|
char _name[100];
|
|
char _mode[8];
|
|
char _uid[8];
|
|
char _gid[8];
|
|
char _size[12];
|
|
char _mtime[12];
|
|
char _checksum[8];
|
|
char _type[1];
|
|
char _linked_name[100];
|
|
|
|
/**
|
|
* Convert ASCII-encoded octal number to unsigned value
|
|
*/
|
|
template <typename T>
|
|
unsigned long _read(T const &field) const
|
|
{
|
|
/*
|
|
* Copy-out ASCII string to temporary buffer that is
|
|
* large enough to host an additional zero.
|
|
*/
|
|
char buf[sizeof(field) + 1];
|
|
strncpy(buf, field, sizeof(buf));
|
|
|
|
unsigned long value = 0;
|
|
ascii_to(buf, &value, 8);
|
|
return value;
|
|
}
|
|
|
|
public:
|
|
|
|
/* length of on data block in tar */
|
|
enum { BLOCK_LEN = 512 };
|
|
|
|
/* record type values */
|
|
enum { TYPE_FILE = 0, TYPE_HARDLINK = 1,
|
|
TYPE_SYMLINK = 2, TYPE_DIR = 5 };
|
|
|
|
size_t size() const { return _read(_size); }
|
|
unsigned uid() const { return _read(_uid); }
|
|
unsigned gid() const { return _read(_gid); }
|
|
unsigned mode() const { return _read(_mode); }
|
|
unsigned type() const { return _read(_type); }
|
|
char const *name() const { return _name; }
|
|
char const *linked_name() const { return _linked_name; }
|
|
|
|
void *data() const { return (char *)this + BLOCK_LEN; }
|
|
};
|
|
|
|
|
|
class Tar_vfs_handle : public Vfs_handle
|
|
{
|
|
private:
|
|
|
|
Record const *_record;
|
|
|
|
public:
|
|
|
|
Tar_vfs_handle(File_system *fs, int status_flags, Record const *record)
|
|
: Vfs_handle(fs, fs, status_flags), _record(record)
|
|
{ }
|
|
|
|
Record const *record() const { return _record; }
|
|
};
|
|
|
|
|
|
/**
|
|
* path element token
|
|
*/
|
|
|
|
struct Scanner_policy_path_element
|
|
{
|
|
static bool identifier_char(char c, unsigned /* i */)
|
|
{
|
|
return (c != '/') && (c != 0);
|
|
}
|
|
};
|
|
|
|
|
|
typedef Genode::Token<Scanner_policy_path_element> Path_element_token;
|
|
|
|
|
|
struct Node : List<Node>, List<Node>::Element
|
|
{
|
|
char const *name;
|
|
Record const *record;
|
|
|
|
Node(char const *name, Record const *record) : name(name), record(record) { }
|
|
|
|
Node *lookup(char const *name)
|
|
{
|
|
Absolute_path lookup_path(name);
|
|
|
|
if (verbose)
|
|
PDBG("lookup_path = %s", lookup_path.base());
|
|
|
|
Node *parent_node = this;
|
|
Node *child_node;
|
|
|
|
Path_element_token t(lookup_path.base());
|
|
|
|
while (t) {
|
|
|
|
if (t.type() != Path_element_token::IDENT) {
|
|
t = t.next();
|
|
continue;
|
|
}
|
|
|
|
char path_element[Sysio::MAX_PATH_LEN];
|
|
|
|
t.string(path_element, sizeof(path_element));
|
|
|
|
if (verbose)
|
|
PDBG("path_element = %s", path_element);
|
|
|
|
for (child_node = parent_node->first(); child_node; child_node = child_node->next()) {
|
|
if (verbose)
|
|
PDBG("comparing with node %s", child_node->name);
|
|
if (strcmp(child_node->name, path_element) == 0) {
|
|
if (verbose)
|
|
PDBG("found matching child node");
|
|
parent_node = child_node;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!child_node)
|
|
return 0;
|
|
|
|
t = t.next();
|
|
}
|
|
|
|
return parent_node;
|
|
}
|
|
|
|
|
|
Node *lookup_child(int index)
|
|
{
|
|
for (Node *child_node = first(); child_node; child_node = child_node->next(), index--) {
|
|
if (index == 0)
|
|
return child_node;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
size_t num_dirent()
|
|
{
|
|
size_t count = 0;
|
|
for (Node *child_node = first(); child_node; child_node = child_node->next(), count++) ;
|
|
return count;
|
|
}
|
|
|
|
} _root_node;
|
|
|
|
|
|
/*
|
|
* Create a Node for a tar record and insert it into the node list
|
|
*/
|
|
class Add_node_action
|
|
{
|
|
private:
|
|
|
|
Node &_root_node;
|
|
|
|
public:
|
|
|
|
Add_node_action(Node &root_node) : _root_node(root_node) { }
|
|
|
|
void operator()(Record const *record)
|
|
{
|
|
Absolute_path current_path(record->name());
|
|
|
|
if (verbose)
|
|
PDBG("current_path = %s", current_path.base());
|
|
|
|
char path_element[Sysio::MAX_PATH_LEN];
|
|
|
|
Path_element_token t(current_path.base());
|
|
|
|
Node *parent_node = &_root_node;
|
|
Node *child_node;
|
|
|
|
while(t) {
|
|
|
|
if (t.type() != Path_element_token::IDENT) {
|
|
t = t.next();
|
|
continue;
|
|
}
|
|
|
|
Absolute_path remaining_path(t.start());
|
|
|
|
t.string(path_element, sizeof(path_element));
|
|
|
|
for (child_node = parent_node->first(); child_node; child_node = child_node->next()) {
|
|
if (strcmp(child_node->name, path_element) == 0)
|
|
break;
|
|
}
|
|
|
|
if (child_node) {
|
|
|
|
if (verbose)
|
|
PDBG("found node for %s", path_element);
|
|
|
|
if (remaining_path.has_single_element()) {
|
|
/* Found a node for the record to be inserted.
|
|
* This is usually a directory node without
|
|
* record. */
|
|
child_node->record = record;
|
|
}
|
|
} else {
|
|
if (remaining_path.has_single_element()) {
|
|
|
|
if (verbose)
|
|
PDBG("creating node for %s", path_element);
|
|
|
|
/*
|
|
* TODO: find 'path_element' in 'record->name'
|
|
* and use the location in the record as name
|
|
* pointer to save some memory
|
|
*/
|
|
size_t name_size = strlen(path_element) + 1;
|
|
char *name = (char*)env()->heap()->alloc(name_size);
|
|
strncpy(name, path_element, name_size);
|
|
child_node = new (env()->heap()) Node(name, record);
|
|
} else {
|
|
|
|
if (verbose)
|
|
PDBG("creating node without record for %s", path_element);
|
|
|
|
/* create a directory node without record */
|
|
size_t name_size = strlen(path_element) + 1;
|
|
char *name = (char*)env()->heap()->alloc(name_size);
|
|
strncpy(name, path_element, name_size);
|
|
child_node = new (env()->heap()) Node(name, 0);
|
|
}
|
|
parent_node->insert(child_node);
|
|
}
|
|
|
|
parent_node = child_node;
|
|
t = t.next();
|
|
}
|
|
}
|
|
};
|
|
|
|
|
|
template <typename Tar_record_action>
|
|
void _for_each_tar_record_do(Tar_record_action tar_record_action)
|
|
{
|
|
/* measure size of archive in blocks */
|
|
unsigned block_id = 0, block_cnt = _tar_size/Record::BLOCK_LEN;
|
|
|
|
/* scan metablocks of archive */
|
|
while (block_id < block_cnt) {
|
|
|
|
Record *record = (Record *)(_tar_base + block_id*Record::BLOCK_LEN);
|
|
|
|
tar_record_action(record);
|
|
|
|
size_t file_size = record->size();
|
|
|
|
/* some datablocks */ /* one metablock */
|
|
block_id = block_id + (file_size / Record::BLOCK_LEN) + 1;
|
|
|
|
/* round up */
|
|
if (file_size % Record::BLOCK_LEN != 0) block_id++;
|
|
|
|
/* check for end of tar archive */
|
|
if (block_id*Record::BLOCK_LEN >= _tar_size)
|
|
break;
|
|
|
|
/* lookout for empty eof-blocks */
|
|
if (*(_tar_base + (block_id*Record::BLOCK_LEN)) == 0x00)
|
|
if (*(_tar_base + (block_id*Record::BLOCK_LEN + 1)) == 0x00)
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
struct Num_dirent_cache
|
|
{
|
|
Lock lock;
|
|
Node &root_node;
|
|
bool valid; /* true after first lookup */
|
|
char key[256]; /* key used for lookup */
|
|
size_t cached_num_dirent; /* cached value */
|
|
|
|
Num_dirent_cache(Node &root_node)
|
|
: root_node(root_node), valid(false), cached_num_dirent(0) { }
|
|
|
|
size_t num_dirent(char const *path)
|
|
{
|
|
Lock::Guard guard(lock);
|
|
|
|
/* check for cache miss */
|
|
if (!valid || strcmp(path, key) != 0) {
|
|
Node *node = root_node.lookup(path);
|
|
if (!node)
|
|
return 0;
|
|
strncpy(key, path, sizeof(key));
|
|
cached_num_dirent = node->num_dirent();
|
|
valid = true;
|
|
}
|
|
return cached_num_dirent;
|
|
}
|
|
} _cached_num_dirent;
|
|
|
|
|
|
public:
|
|
|
|
Tar_file_system(Xml_node config)
|
|
:
|
|
_rom_name(config), _rom(_rom_name.name),
|
|
_tar_base(env()->rm_session()->attach(_rom.dataspace())),
|
|
_tar_size(Dataspace_client(_rom.dataspace()).size()),
|
|
_root_node("", 0),
|
|
_cached_num_dirent(_root_node)
|
|
{
|
|
PINF("tar archive '%s' local at %p, size is %zd",
|
|
_rom_name.name, _tar_base, _tar_size);
|
|
|
|
_for_each_tar_record_do(Add_node_action(_root_node));
|
|
}
|
|
|
|
|
|
/*********************************
|
|
** Directory-service interface **
|
|
*********************************/
|
|
|
|
Dataspace_capability dataspace(char const *path)
|
|
{
|
|
/*
|
|
* Walk hardlinks until we reach a file
|
|
*/
|
|
Record const *record = 0;
|
|
for (;;) {
|
|
Node *node = _root_node.lookup(path);
|
|
|
|
if (!node)
|
|
return Dataspace_capability();
|
|
|
|
record = node->record;
|
|
|
|
if (record) {
|
|
if (record->type() == Record::TYPE_HARDLINK) {
|
|
path = record->linked_name();
|
|
continue;
|
|
}
|
|
|
|
if (record->type() == Record::TYPE_FILE)
|
|
break;
|
|
|
|
PERR("TAR record \"%s\" has unsupported type %d",
|
|
record->name(), record->type());
|
|
}
|
|
|
|
PERR("TAR record \"%s\" has unsupported type %d",
|
|
path, Record::TYPE_DIR);
|
|
|
|
return Dataspace_capability();
|
|
}
|
|
|
|
try {
|
|
Ram_dataspace_capability ds_cap =
|
|
env()->ram_session()->alloc(record->size());
|
|
|
|
void *local_addr = env()->rm_session()->attach(ds_cap);
|
|
memcpy(local_addr, record->data(), record->size());
|
|
env()->rm_session()->detach(local_addr);
|
|
|
|
return ds_cap;
|
|
}
|
|
catch (...) { PDBG("Could not create new dataspace"); }
|
|
|
|
return Dataspace_capability();
|
|
}
|
|
|
|
void release(char const *, Dataspace_capability ds_cap)
|
|
{
|
|
env()->ram_session()->free(static_cap_cast<Ram_dataspace>(ds_cap));
|
|
}
|
|
|
|
bool stat(Sysio *sysio, char const *path)
|
|
{
|
|
if (verbose)
|
|
PDBG("path = %s", path);
|
|
|
|
Node const *node = 0;
|
|
Record const *record = 0;
|
|
|
|
/*
|
|
* Walk hardlinks until we reach a file
|
|
*/
|
|
for (;;) {
|
|
node = _root_node.lookup(path);
|
|
|
|
if (!node) {
|
|
sysio->error.stat = Sysio::STAT_ERR_NO_ENTRY;
|
|
return false;
|
|
}
|
|
|
|
record = node->record;
|
|
|
|
if (record) {
|
|
if (record->type() == Record::TYPE_HARDLINK) {
|
|
path = record->linked_name();
|
|
continue;
|
|
} else
|
|
break;
|
|
} else {
|
|
if (verbose)
|
|
PDBG("found a virtual directoty node");
|
|
memset(&sysio->stat_out.st, 0, sizeof(sysio->stat_out.st));
|
|
sysio->stat_out.st.mode = Sysio::STAT_MODE_DIRECTORY;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/* convert TAR record modes to stat modes */
|
|
unsigned mode = record->mode();
|
|
switch (record->type()) {
|
|
case Record::TYPE_FILE: mode |= Sysio::STAT_MODE_FILE; break;
|
|
case Record::TYPE_SYMLINK: mode |= Sysio::STAT_MODE_SYMLINK; break;
|
|
case Record::TYPE_DIR: mode |= Sysio::STAT_MODE_DIRECTORY; break;
|
|
|
|
default:
|
|
if (verbose)
|
|
PDBG("unhandled record type %d", record->type());
|
|
}
|
|
|
|
memset(&sysio->stat_out.st, 0, sizeof(sysio->stat_out.st));
|
|
sysio->stat_out.st.mode = mode;
|
|
sysio->stat_out.st.size = record->size();
|
|
sysio->stat_out.st.uid = record->uid();
|
|
sysio->stat_out.st.gid = record->gid();
|
|
sysio->stat_out.st.inode = (unsigned long)node;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool dirent(Sysio *sysio, char const *path, off_t index)
|
|
{
|
|
Lock::Guard guard(_lock);
|
|
|
|
Node *node = _root_node.lookup(path);
|
|
|
|
if (!node)
|
|
return false;
|
|
|
|
node = node->lookup_child(index);
|
|
|
|
if (!node) {
|
|
sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_END;
|
|
return true;
|
|
}
|
|
|
|
sysio->dirent_out.entry.fileno = (unsigned long)node;
|
|
|
|
Record const *record = node->record;
|
|
|
|
if (record) {
|
|
switch (record->type()) {
|
|
case 0: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_FILE; break;
|
|
case 2: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_SYMLINK; break;
|
|
case 5: sysio->dirent_out.entry.type = Sysio::DIRENT_TYPE_DIRECTORY; break;
|
|
|
|
default:
|
|
if (verbose)
|
|
PDBG("unhandled record type %d", record->type());
|
|
}
|
|
}
|
|
|
|
strncpy(sysio->dirent_out.entry.name,
|
|
node->name,
|
|
sizeof(sysio->dirent_out.entry.name));
|
|
|
|
return true;
|
|
}
|
|
|
|
bool unlink(Sysio *, char const *) { return false; }
|
|
|
|
bool readlink(Sysio *sysio, char const *path)
|
|
{
|
|
Node *node = _root_node.lookup(path);
|
|
Record const *record = node ? node->record : 0;
|
|
|
|
if (!record || (record->type() != Record::TYPE_SYMLINK)) {
|
|
sysio->error.readlink = Sysio::READLINK_ERR_NO_ENTRY;
|
|
return false;
|
|
}
|
|
|
|
size_t const count = min(sysio->readlink_in.bufsiz,
|
|
min(sizeof(sysio->readlink_out.chunk),
|
|
(size_t)100));
|
|
|
|
memcpy(sysio->readlink_out.chunk, record->linked_name(), count);
|
|
|
|
sysio->readlink_out.count = count;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool rename(Sysio *, char const *, char const *) { return false; }
|
|
|
|
bool mkdir(Sysio *, char const *) { return false; }
|
|
|
|
bool symlink(Sysio *, char const *) { return false; }
|
|
|
|
size_t num_dirent(char const *path)
|
|
{
|
|
return _cached_num_dirent.num_dirent(path);
|
|
}
|
|
|
|
bool is_directory(char const *path)
|
|
{
|
|
Node *node = _root_node.lookup(path);
|
|
|
|
if (!node)
|
|
return false;
|
|
|
|
Record const *record = node->record;
|
|
|
|
return record ? (record->type() == Record::TYPE_DIR) : true;
|
|
}
|
|
|
|
char const *leaf_path(char const *path)
|
|
{
|
|
/*
|
|
* Check if path exists within the file system. If this is the
|
|
* case, return the whole path, which is relative to the root
|
|
* of this file system.
|
|
*/
|
|
Node *node = _root_node.lookup(path);
|
|
return node ? path : 0;
|
|
}
|
|
|
|
Vfs_handle *open(Sysio *sysio, char const *path)
|
|
{
|
|
Lock::Guard guard(_lock);
|
|
|
|
Node *node = _root_node.lookup(path);
|
|
if (node)
|
|
return new (env()->heap())
|
|
Tar_vfs_handle(this, 0, node->record);
|
|
|
|
sysio->error.open = Sysio::OPEN_ERR_UNACCESSIBLE;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/***************************
|
|
** File_system interface **
|
|
***************************/
|
|
|
|
static char const *name() { return "tar"; }
|
|
|
|
|
|
/********************************
|
|
** File I/O service interface **
|
|
********************************/
|
|
|
|
bool write(Sysio *sysio, Vfs_handle *handle)
|
|
{
|
|
PDBG("called\n");
|
|
return false;
|
|
}
|
|
|
|
bool read(Sysio *sysio, Vfs_handle *vfs_handle)
|
|
{
|
|
Tar_vfs_handle const *handle = static_cast<Tar_vfs_handle *>(vfs_handle);
|
|
|
|
size_t const record_size = handle->record()->size();
|
|
|
|
size_t const record_bytes_left = record_size >= handle->seek()
|
|
? record_size - handle->seek() : 0;
|
|
|
|
size_t const count = min(record_bytes_left,
|
|
min(sizeof(sysio->read_out.chunk),
|
|
sysio->read_in.count));
|
|
|
|
char const *data = (char *)handle->record()->data() + handle->seek();
|
|
|
|
memcpy(sysio->read_out.chunk, data, count);
|
|
|
|
sysio->read_out.count = count;
|
|
return true;
|
|
}
|
|
|
|
bool ftruncate(Sysio *sysio, Vfs_handle *handle)
|
|
{
|
|
PDBG("called\n");
|
|
return false;
|
|
}
|
|
};
|
|
}
|
|
|
|
#endif /* _NOUX__TAR_FILE_SYSTEM_H_ */
|