transmission/libtransmission/blocklist.cc

392 lines
9.6 KiB
C++

// This file Copyright © 2008-2022 Mnemosyne LLC.
// It may be used under GPLv2 (SPDX: GPL-2.0-only), GPLv3 (SPDX: GPL-3.0-only),
// or any future license endorsed by Mnemosyne LLC.
// License text can be found in the licenses/ folder.
#include <algorithm>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <string_view>
#include <fmt/core.h>
#include "transmission.h"
#include "blocklist.h"
#include "error.h"
#include "file.h"
#include "log.h"
#include "net.h"
#include "utils.h"
/***
**** PRIVATE
***/
void BlocklistFile::close()
{
if (rules_ != nullptr)
{
tr_sys_file_unmap(rules_, byte_count_);
tr_sys_file_close(fd_);
rules_ = nullptr;
rule_count_ = 0;
byte_count_ = 0;
fd_ = TR_BAD_SYS_FILE;
}
}
void BlocklistFile::load()
{
close();
auto info = tr_sys_path_info{};
if (!tr_sys_path_get_info(getFilename(), 0, &info))
{
return;
}
auto const byteCount = info.size;
if (byteCount == 0)
{
return;
}
tr_error* error = nullptr;
auto const fd = tr_sys_file_open(getFilename(), TR_SYS_FILE_READ, 0, &error);
if (fd == TR_BAD_SYS_FILE)
{
tr_logAddWarn(fmt::format(
_("Couldn't read '{path}': {error} ({error_code})"),
fmt::arg("path", getFilename()),
fmt::arg("error", error->message),
fmt::arg("error_code", error->code)));
tr_error_free(error);
return;
}
rules_ = static_cast<struct IPv4Range*>(tr_sys_file_map_for_reading(fd, 0, byteCount, &error));
if (rules_ == nullptr)
{
tr_logAddWarn(fmt::format(
_("Couldn't read '{path}': {error} ({error_code})"),
fmt::arg("path", getFilename()),
fmt::arg("error", error->message),
fmt::arg("error_code", error->code)));
tr_sys_file_close(fd);
tr_error_free(error);
return;
}
fd_ = fd;
byte_count_ = byteCount;
rule_count_ = byteCount / sizeof(IPv4Range);
tr_logAddInfo(fmt::format(
ngettext("Blocklist '{path}' has {count} entry", "Blocklist '{path}' has {count} entries", rule_count_),
fmt::arg("path", tr_sys_path_basename(getFilename())),
fmt::arg("count", rule_count_)));
}
void BlocklistFile::ensureLoaded()
{
if (rules_ == nullptr)
{
load();
}
}
// TODO: unused
//static void blocklistDelete(tr_blocklistFile* b)
//{
// blocklistClose(b);
// tr_sys_path_remove(b->filename, nullptr);
//}
/***
**** PACKAGE-VISIBLE
***/
bool BlocklistFile::hasAddress(tr_address const& addr)
{
TR_ASSERT(tr_address_is_valid(&addr));
if (!is_enabled_ || addr.type == TR_AF_INET6)
{
return false;
}
ensureLoaded();
if (rules_ == nullptr || rule_count_ == 0)
{
return false;
}
auto const needle = ntohl(addr.addr.addr4.s_addr);
// std::binary_search works differently and requires a less-than comparison
// and two arguments of the same type. std::bsearch is the right choice.
auto const* range = static_cast<IPv4Range const*>(
std::bsearch(&needle, rules_, rule_count_, sizeof(IPv4Range), IPv4Range::compareAddressToRange));
return range != nullptr;
}
/*
* P2P plaintext format: "comment:x.x.x.x-y.y.y.y"
* http://wiki.phoenixlabs.org/wiki/P2P_Format
* https://en.wikipedia.org/wiki/PeerGuardian#P2P_plaintext_format
*/
bool BlocklistFile::parseLine1(std::string_view line, struct IPv4Range* range)
{
// remove leading "comment:"
auto pos = line.find(':');
if (pos == std::string_view::npos)
{
return false;
}
line = line.substr(pos + 1);
// parse the leading 'x.x.x.x'
pos = line.find('-');
if (pos == std::string_view::npos)
{
return false;
}
if (auto addr = tr_address{}; tr_address_from_string(&addr, line.substr(0, pos)))
{
range->begin_ = ntohl(addr.addr.addr4.s_addr);
}
else
{
return false;
}
line = line.substr(pos + 1);
// parse the trailing 'y.y.y.y'
if (auto addr = tr_address{}; tr_address_from_string(&addr, line))
{
range->end_ = ntohl(addr.addr.addr4.s_addr);
}
else
{
return false;
}
return true;
}
/*
* DAT / eMule format: "000.000.000.000 - 000.255.255.255 , 000 , invalid ip"a
* https://sourceforge.net/p/peerguardian/wiki/dev-blocklist-format-dat/
*/
bool BlocklistFile::parseLine2(std::string_view line, struct IPv4Range* range)
{
static auto constexpr Delim1 = std::string_view{ " - " };
static auto constexpr Delim2 = std::string_view{ " , " };
auto pos = line.find(Delim1);
if (pos == std::string_view::npos)
{
return false;
}
if (auto addr = tr_address{}; tr_address_from_string(&addr, line.substr(0, pos)))
{
range->begin_ = ntohl(addr.addr.addr4.s_addr);
}
else
{
return false;
}
line = line.substr(pos + std::size(Delim1));
pos = line.find(Delim2);
if (pos == std::string_view::npos)
{
return false;
}
if (auto addr = tr_address{}; tr_address_from_string(&addr, line.substr(0, pos)))
{
range->end_ = ntohl(addr.addr.addr4.s_addr);
}
else
{
return false;
}
return true;
}
/*
* CIDR notation: "0.0.0.0/8", IPv4 only
* https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation
*/
bool BlocklistFile::parseLine3(char const* line, IPv4Range* range)
{
unsigned int ip[4];
unsigned int pflen = 0;
uint32_t ip_u = 0;
uint32_t mask = 0xffffffff;
if (sscanf(line, "%u.%u.%u.%u/%u", TR_ARG_TUPLE(&ip[0], &ip[1], &ip[2], &ip[3]), &pflen) != 5)
{
return false;
}
if (pflen > 32 || ip[0] > 0xff || ip[1] > 0xff || ip[2] > 0xff || ip[3] > 0xff)
{
return false;
}
/* this is host order */
mask <<= 32 - pflen;
ip_u = ip[0] << 24 | ip[1] << 16 | ip[2] << 8 | ip[3];
/* fill the non-prefix bits the way we need it */
range->begin_ = ip_u & mask;
range->end_ = ip_u | (~mask);
return true;
}
bool BlocklistFile::parseLine(char const* line, IPv4Range* range)
{
return parseLine1(line, range) || parseLine2(line, range) || parseLine3(line, range);
}
bool BlocklistFile::compareAddressRangesByFirstAddress(IPv4Range const& a, IPv4Range const& b)
{
return a.begin_ < b.begin_;
}
size_t BlocklistFile::setContent(char const* filename)
{
int inCount = 0;
char line[2048];
tr_error* error = nullptr;
if (filename == nullptr)
{
return 0;
}
auto const in = tr_sys_file_open(filename, TR_SYS_FILE_READ, 0, &error);
if (in == TR_BAD_SYS_FILE)
{
tr_logAddWarn(fmt::format(
_("Couldn't read '{path}': {error} ({error_code})"),
fmt::arg("path", filename),
fmt::arg("error", error->message),
fmt::arg("error_code", error->code)));
tr_error_free(error);
return 0;
}
close();
auto const out = tr_sys_file_open(
getFilename(),
TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE | TR_SYS_FILE_TRUNCATE,
0666,
&error);
if (out == TR_BAD_SYS_FILE)
{
tr_logAddWarn(fmt::format(
_("Couldn't read '{path}': {error} ({error_code})"),
fmt::arg("path", getFilename()),
fmt::arg("error", error->message),
fmt::arg("error_code", error->code)));
tr_error_free(error);
tr_sys_file_close(in);
return 0;
}
/* load the rules into memory */
std::vector<IPv4Range> ranges;
while (tr_sys_file_read_line(in, line, sizeof(line)))
{
IPv4Range range = {};
++inCount;
if (!parseLine(line, &range))
{
/* don't try to display the actual lines - it causes issues */
tr_logAddWarn(fmt::format(_("Couldn't parse line: '{line}'"), fmt::arg("line", inCount)));
continue;
}
ranges.push_back(range);
}
if (!std::empty(ranges)) // sort and merge
{
size_t keep = 0; // index in ranges
std::sort(std::begin(ranges), std::end(ranges), BlocklistFile::compareAddressRangesByFirstAddress);
// merge
for (auto const& r : ranges)
{
if (ranges[keep].end_ < r.begin_)
{
ranges[++keep] = r;
}
else if (ranges[keep].end_ < r.end_)
{
ranges[keep].end_ = r.end_;
}
}
TR_ASSERT_MSG(keep + 1 <= std::size(ranges), "Can shrink `ranges` or leave intact, but not grow");
ranges.resize(keep + 1);
#ifdef TR_ENABLE_ASSERTS
assertValidRules(ranges);
#endif
}
if (!tr_sys_file_write(out, ranges.data(), sizeof(IPv4Range) * std::size(ranges), nullptr, &error))
{
tr_logAddWarn(fmt::format(
_("Couldn't save '{path}': {error} ({error_code})"),
fmt::arg("path", getFilename()),
fmt::arg("error", error->message),
fmt::arg("error_code", error->code)));
tr_error_free(error);
}
else
{
tr_logAddInfo(fmt::format(
ngettext("Blocklist '{path}' has {count} entry", "Blocklist '{path}' has {count} entries", rule_count_),
fmt::arg("path", tr_sys_path_basename(getFilename())),
fmt::arg("count", rule_count_)));
}
tr_sys_file_close(out);
tr_sys_file_close(in);
load();
return std::size(ranges);
}
#ifdef TR_ENABLE_ASSERTS
void BlocklistFile::assertValidRules(std::vector<IPv4Range>& ranges)
{
for (auto const& r : ranges)
{
TR_ASSERT(r.begin_ <= r.end_);
}
for (size_t i = 1; i < std::size(ranges); ++i)
{
TR_ASSERT(ranges[i - 1].end_ < ranges[i].begin_);
}
}
#endif