1 files changed, 220 insertions, 0 deletions
diff --git a/src/common/config.cpp b/src/common/config.cpp
new file mode 100644
index 0000000000..747503ad2a
--- /dev/null
+++ b/src/common/config.cpp
@@ -0,0 +1,220 @@
+// Copyright (c) 2023 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <common/args.h>
+
+#include <logging.h>
+#include <sync.h>
+#include <tinyformat.h>
+#include <univalue.h>
+#include <util/fs.h>
+#include <util/settings.h>
+#include <util/string.h>
+
+#include <algorithm>
+#include <cassert>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <list>
+#include <map>
+#include <memory>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
+
+fs::path GetConfigFile(const ArgsManager& args, const fs::path& configuration_file_path)
+{
+    return AbsPathForConfigVal(args, configuration_file_path, /*net_specific=*/false);
+}
+
+static bool GetConfigOptions(std::istream& stream, const std::string& filepath, std::string& error, std::vector<std::pair<std::string, std::string>>& options, std::list<SectionInfo>& sections)
+{
+    std::string str, prefix;
+    std::string::size_type pos;
+    int linenr = 1;
+    while (std::getline(stream, str)) {
+        bool used_hash = false;
+        if ((pos = str.find('#')) != std::string::npos) {
+            str = str.substr(0, pos);
+            used_hash = true;
+        }
+        const static std::string pattern = " \t\r\n";
+        str = TrimString(str, pattern);
+        if (!str.empty()) {
+            if (*str.begin() == '[' && *str.rbegin() == ']') {
+                const std::string section = str.substr(1, str.size() - 2);
+                sections.emplace_back(SectionInfo{section, filepath, linenr});
+                prefix = section + '.';
+            } else if (*str.begin() == '-') {
+                error = strprintf("parse error on line %i: %s, options in configuration file must be specified without leading -", linenr, str);
+                return false;
+            } else if ((pos = str.find('=')) != std::string::npos) {
+                std::string name = prefix + TrimString(std::string_view{str}.substr(0, pos), pattern);
+                std::string_view value = TrimStringView(std::string_view{str}.substr(pos + 1), pattern);
+                if (used_hash && name.find("rpcpassword") != std::string::npos) {
+                    error = strprintf("parse error on line %i, using # in rpcpassword can be ambiguous and should be avoided", linenr);
+                    return false;
+                }
+                options.emplace_back(name, value);
+                if ((pos = name.rfind('.')) != std::string::npos && prefix.length() <= pos) {
+                    sections.emplace_back(SectionInfo{name.substr(0, pos), filepath, linenr});
+                }
+            } else {
+                error = strprintf("parse error on line %i: %s", linenr, str);
+                if (str.size() >= 2 && str.substr(0, 2) == "no") {
+                    error += strprintf(", if you intended to specify a negated option, use %s=1 instead", str);
+                }
+                return false;
+            }
+        }
+        ++linenr;
+    }
+    return true;
+}
+
+bool IsConfSupported(KeyInfo& key, std::string& error) {
+    if (key.name == "conf") {
+        error = "conf cannot be set in the configuration file; use includeconf= if you want to include additional config files";
+        return false;
+    }
+    if (key.name == "reindex") {
+        // reindex can be set in a config file but it is strongly discouraged as this will cause the node to reindex on
+        // every restart. Allow the config but throw a warning
+        LogPrintf("Warning: reindex=1 is set in the configuration file, which will significantly slow down startup. Consider removing or commenting out this option for better performance, unless there is currently a condition which makes rebuilding the indexes necessary\n");
+        return true;
+    }
+    return true;
+}
+
+bool ArgsManager::ReadConfigStream(std::istream& stream, const std::string& filepath, std::string& error, bool ignore_invalid_keys)
+{
+    LOCK(cs_args);
+    std::vector<std::pair<std::string, std::string>> options;
+    if (!GetConfigOptions(stream, filepath, error, options, m_config_sections)) {
+        return false;
+    }
+    for (const std::pair<std::string, std::string>& option : options) {
+        KeyInfo key = InterpretKey(option.first);
+        std::optional<unsigned int> flags = GetArgFlags('-' + key.name);
+        if (!IsConfSupported(key, error)) return false;
+        if (flags) {
+            std::optional<util::SettingsValue> value = InterpretValue(key, &option.second, *flags, error);
+            if (!value) {
+                return false;
+            }
+            m_settings.ro_config[key.section][key.name].push_back(*value);
+        } else {
+            if (ignore_invalid_keys) {
+                LogPrintf("Ignoring unknown configuration value %s\n", option.first);
+            } else {
+                error = strprintf("Invalid configuration value %s", option.first);
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
+{
+    {
+        LOCK(cs_args);
+        m_settings.ro_config.clear();
+        m_config_sections.clear();
+    }
+
+    const auto conf_path{GetConfigFilePath()};
+    std::ifstream stream{conf_path};
+
+    // not ok to have a config file specified that cannot be opened
+    if (IsArgSet("-conf") && !stream.good()) {
+        error = strprintf("specified config file \"%s\" could not be opened.", fs::PathToString(conf_path));
+        return false;
+    }
+    // ok to not have a config file
+    if (stream.good()) {
+        if (!ReadConfigStream(stream, fs::PathToString(conf_path), error, ignore_invalid_keys)) {
+            return false;
+        }
+        // `-includeconf` cannot be included in the command line arguments except
+        // as `-noincludeconf` (which indicates that no included conf file should be used).
+        bool use_conf_file{true};
+        {
+            LOCK(cs_args);
+            if (auto* includes = util::FindKey(m_settings.command_line_options, "includeconf")) {
+                // ParseParameters() fails if a non-negated -includeconf is passed on the command-line
+                assert(util::SettingsSpan(*includes).last_negated());
+                use_conf_file = false;
+            }
+        }
+        if (use_conf_file) {
+            std::string chain_id = GetChainName();
+            std::vector<std::string> conf_file_names;
+
+            auto add_includes = [&](const std::string& network, size_t skip = 0) {
+                size_t num_values = 0;
+                LOCK(cs_args);
+                if (auto* section = util::FindKey(m_settings.ro_config, network)) {
+                    if (auto* values = util::FindKey(*section, "includeconf")) {
+                        for (size_t i = std::max(skip, util::SettingsSpan(*values).negated()); i < values->size(); ++i) {
+                            conf_file_names.push_back((*values)[i].get_str());
+                        }
+                        num_values = values->size();
+                    }
+                }
+                return num_values;
+            };
+
+            // We haven't set m_network yet (that happens in SelectParams()), so manually check
+            // for network.includeconf args.
+            const size_t chain_includes = add_includes(chain_id);
+            const size_t default_includes = add_includes({});
+
+            for (const std::string& conf_file_name : conf_file_names) {
+                std::ifstream conf_file_stream{GetConfigFile(*this, fs::PathFromString(conf_file_name))};
+                if (conf_file_stream.good()) {
+                    if (!ReadConfigStream(conf_file_stream, conf_file_name, error, ignore_invalid_keys)) {
+                        return false;
+                    }
+                    LogPrintf("Included configuration file %s\n", conf_file_name);
+                } else {
+                    error = "Failed to include configuration file " + conf_file_name;
+                    return false;
+                }
+            }
+
+            // Warn about recursive -includeconf
+            conf_file_names.clear();
+            add_includes(chain_id, /* skip= */ chain_includes);
+            add_includes({}, /* skip= */ default_includes);
+            std::string chain_id_final = GetChainName();
+            if (chain_id_final != chain_id) {
+                // Also warn about recursive includeconf for the chain that was specified in one of the includeconfs
+                add_includes(chain_id_final);
+            }
+            for (const std::string& conf_file_name : conf_file_names) {
+                tfm::format(std::cerr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", conf_file_name);
+            }
+        }
+    }
+
+    // If datadir is changed in .conf file:
+    ClearPathCache();
+    if (!CheckDataDirOption(*this)) {
+        error = strprintf("specified data directory \"%s\" does not exist.", GetArg("-datadir", ""));
+        return false;
+    }
+    return true;
+}
+
+fs::path AbsPathForConfigVal(const ArgsManager& args, const fs::path& path, bool net_specific)
+{
+    if (path.is_absolute()) {
+        return path;
+    }
+    return fsbridge::AbsPathJoin(net_specific ? args.GetDataDirNet() : args.GetDataDirBase(), path);
+}