// convert a bdecode_node into an old skool entry
void entry::operator=(bdecode_node const& e)
{
switch (e.type())
{
case bdecode_node::string_t:
this->string() = e.string_value();
break;
case bdecode_node::int_t:
this->integer() = e.int_value();
break;
case bdecode_node::dict_t:
{
dictionary_type& d = this->dict();
for (int i = 0; i < e.dict_size(); ++i)
{
std::pair<std::string, bdecode_node> elem = e.dict_at(i);
d[elem.first] = elem.second;
}
break;
}
case bdecode_node::list_t:
{
list_type& l = this->list();
for (int i = 0; i < e.list_size(); ++i)
{
l.push_back(entry());
l.back() = e.list_at(i);
}
break;
}
case bdecode_node::none_t:
destruct();
break;
}
}
void on_read(lt::error_code const& ec, std::size_t bytes_transferred)
{
if (ec) return;
using libtorrent::entry;
using libtorrent::bdecode;
int pos;
error_code err;
// since the simulation is single threaded, we can get away with just
// allocating a single of these
static bdecode_node msg;
int ret = bdecode(m_buffer, m_buffer + bytes_transferred, msg, err, &pos, 10, 500);
if (ret != 0) return;
if (msg.type() != bdecode_node::dict_t) return;
libtorrent::dht::msg m(msg, m_ep);
dht().incoming(m);
sock().async_receive_from(asio::mutable_buffers_1(m_buffer, sizeof(m_buffer))
, m_ep, [&](lt::error_code const& ec, std::size_t bytes_transferred)
{ this->on_read(ec, bytes_transferred); });
}
void render_variant(std::string& out, bdecode_node const& e)
{
switch (e.type())
{
case bdecode_node::dict_t:
print_dict(out);
for (int i = 0; i < e.dict_size(); ++i)
{
std::pair<lt::string_view, bdecode_node> item = e.dict_at(i);
const bool duplicate = g_seed == 1;
const bool skipped = g_seed == 2;
g_seed -= 2;
if (duplicate)
{
print_string(out, item.first.to_string());
render_variant(out, item.second);
}
if (!skipped)
{
print_string(out, item.first.to_string());
render_variant(out, item.second);
}
render_arbitrary_item(out);
}
print_terminate(out);
break;
case bdecode_node::list_t:
print_list(out);
for (int i = 0; i < e.list_size(); ++i)
{
const bool duplicate = g_seed == 1;
const bool skipped = g_seed == 2;
g_seed -= 2;
if (duplicate) render_variant(out, e.list_at(i));
render_arbitrary_item(out);
if (!skipped) render_variant(out, e.list_at(i));
}
print_terminate(out);
break;
case bdecode_node::int_t:
print_int(out, e.int_value());
break;
case bdecode_node::string_t:
print_string(out, e.string_value().to_string());
break;
default:
abort();
}
}
// root_dir is the name of the torrent, unless this is a single file
// torrent, in which case it's empty.
bool extract_files(bdecode_node const& list, file_storage& target
, std::string const& root_dir, ptrdiff_t info_ptr_diff, error_code& ec)
{
if (list.type() != bdecode_node::list_t)
{
ec = errors::torrent_file_parse_failed;
return false;
}
target.reserve(list.list_size());
// this is the counter used to name pad files
int pad_file_cnt = 0;
for (int i = 0, end(list.list_size()); i < end; ++i)
{
if (!extract_single_file(list.list_at(i), target, root_dir
, info_ptr_diff, false, pad_file_cnt, ec))
return false;
}
return true;
}
// TODO: 2 returning a bool here is redundant. Instead this function should
// return the peer_entry
bool extract_peer_info(bdecode_node const& info, peer_entry& ret, error_code& ec)
{
// extract peer id (if any)
if (info.type() != bdecode_node::dict_t)
{
ec.assign(errors::invalid_peer_dict, get_libtorrent_category());
return false;
}
bdecode_node i = info.dict_find_string("peer id");
if (i && i.string_length() == 20)
{
std::copy(i.string_ptr(), i.string_ptr()+20, ret.pid.begin());
}
else
{
// if there's no peer_id, just initialize it to a bunch of zeroes
std::fill_n(ret.pid.begin(), 20, 0);
}
// extract ip
i = info.dict_find_string("ip");
if (i == 0)
{
ec.assign(errors::invalid_tracker_response, get_libtorrent_category());
return false;
}
ret.hostname = i.string_value();
// extract port
i = info.dict_find_int("port");
if (i == 0)
{
ec.assign(errors::invalid_tracker_response, get_libtorrent_category());
return false;
}
ret.port = boost::uint16_t(i.int_value());
return true;
}
std::string print_entry(bdecode_node const& e
, bool single_line, int indent)
{
char indent_str[200];
using std::memset;
memset(indent_str, ' ', 200);
indent_str[0] = ',';
indent_str[1] = '\n';
indent_str[199] = 0;
if (indent < 197 && indent >= 0) indent_str[indent+2] = 0;
std::string ret;
switch (e.type())
{
case bdecode_node::none_t: return "none";
case bdecode_node::int_t:
{
char str[100];
snprintf(str, sizeof(str), "%" PRId64, e.int_value());
return str;
}
case bdecode_node::string_t:
{
print_string(ret, e.string_ptr(), e.string_length(), single_line);
return ret;
}
case bdecode_node::list_t:
{
ret += '[';
bool one_liner = line_longer_than(e, 200) != -1 || single_line;
if (!one_liner) ret += indent_str + 1;
for (int i = 0; i < e.list_size(); ++i)
{
if (i == 0 && one_liner) ret += " ";
ret += print_entry(e.list_at(i), single_line, indent + 2);
if (i < e.list_size() - 1) ret += (one_liner?", ":indent_str);
else ret += (one_liner?" ":indent_str+1);
}
ret += "]";
return ret;
}
case bdecode_node::dict_t:
{
ret += "{";
bool one_liner = line_longer_than(e, 200) != -1 || single_line;
if (!one_liner) ret += indent_str+1;
for (int i = 0; i < e.dict_size(); ++i)
{
if (i == 0 && one_liner) ret += " ";
std::pair<std::string, bdecode_node> ent = e.dict_at(i);
print_string(ret, ent.first.c_str(), ent.first.size(), true);
ret += ": ";
ret += print_entry(ent.second, single_line, indent + 2);
if (i < e.dict_size() - 1) ret += (one_liner?", ":indent_str);
else ret += (one_liner?" ":indent_str+1);
}
ret += "}";
return ret;
}
}
return ret;
}
// 'top_level' is extracting the file for a single-file torrent. The
// distinction is that the filename is found in "name" rather than
// "path"
// root_dir is the name of the torrent, unless this is a single file
// torrent, in which case it's empty.
bool extract_single_file(bdecode_node const& dict, file_storage& files
, std::string const& root_dir, ptrdiff_t info_ptr_diff, bool top_level
, int& pad_file_cnt, error_code& ec)
{
if (dict.type() != bdecode_node::dict_t) return false;
boost::uint32_t file_flags = get_file_attributes(dict);
// symlinks have an implied "size" of zero. i.e. they use up 0 bytes of
// the torrent payload space
boost::int64_t const file_size = (file_flags & file_storage::flag_symlink)
? 0
: dict.dict_find_int_value("length", -1);
if (file_size < 0 )
{
ec = errors::torrent_invalid_length;
return false;
}
boost::int64_t const mtime = dict.dict_find_int_value("mtime", 0);
std::string path = root_dir;
std::string path_element;
char const* filename = NULL;
int filename_len = 0;
if (top_level)
{
// prefer the name.utf-8 because if it exists, it is more likely to be
// correctly encoded
bdecode_node p = dict.dict_find_string("name.utf-8");
if (!p) p = dict.dict_find_string("name");
if (!p || p.string_length() == 0)
{
ec = errors::torrent_missing_name;
return false;
}
filename = p.string_ptr() + info_ptr_diff;
filename_len = p.string_length();
while (filename_len > 0 && filename[0] == TORRENT_SEPARATOR)
{
filename += 1;
filename_len -= 1;
}
sanitize_append_path_element(path, p.string_ptr(), p.string_length());
}
else
{
bdecode_node p = dict.dict_find_list("path.utf-8");
if (!p) p = dict.dict_find_list("path");
if (p && p.list_size() > 0)
{
std::size_t const orig_path_len = path.size();
int const preallocate = path.size() + path_length(p, ec);
if (ec) return false;
path.reserve(preallocate);
for (int i = 0, end(p.list_size()); i < end; ++i)
{
bdecode_node e = p.list_at(i);
if (i == end - 1)
{
filename = e.string_ptr() + info_ptr_diff;
filename_len = e.string_length();
}
while (filename_len > 0 && filename[0] == TORRENT_SEPARATOR)
{
filename += 1;
filename_len -= 1;
}
sanitize_append_path_element(path, e.string_ptr(), e.string_length());
}
// if all path elements were sanitized away, we need to use another
// name instead
if (path.size() == orig_path_len)
{
path += TORRENT_SEPARATOR;
path += "_";
}
}
else if (file_flags & file_storage::flag_pad_file)
{
// pad files don't need a path element, we'll just store them
// under the .pad directory
char cnt[10];
snprintf(cnt, sizeof(cnt), "%d", pad_file_cnt);
path = combine_path(".pad", cnt);
++pad_file_cnt;
}
else
{
ec = errors::torrent_missing_name;
return false;
}
}
// bitcomet pad file
if (path.find("_____padding_file_") != std::string::npos)
file_flags = file_storage::flag_pad_file;
bdecode_node fh = dict.dict_find_string("sha1");
char const* filehash = NULL;
if (fh && fh.string_length() == 20)
filehash = fh.string_ptr() + info_ptr_diff;
std::string symlink_path;
if (file_flags & file_storage::flag_symlink)
{
if (bdecode_node s_p = dict.dict_find_list("symlink path"))
{
int const preallocate = path_length(s_p, ec);
if (ec) return false;
symlink_path.reserve(preallocate);
for (int i = 0, end(s_p.list_size()); i < end; ++i)
{
bdecode_node const& n = s_p.list_at(i);
sanitize_append_path_element(symlink_path, n.string_ptr()
, n.string_length());
}
}
}
else
{
file_flags &= ~file_storage::flag_symlink;
}
if (filename_len > path.length()
|| path.compare(path.size() - filename_len, filename_len, filename
, filename_len) != 0)
{
// if the filename was sanitized and differ, clear it to just use path
filename = NULL;
filename_len = 0;
}
files.add_file_borrow(filename, filename_len, path, file_size, file_flags, filehash
, mtime, symlink_path);
return true;
}