Line data Source code
1 : // Copyright (c) 2019-2022 The Bitcoin Core developers
2 : // Distributed under the MIT software license, see the accompanying
3 : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 :
5 : #include <common/settings.h>
6 :
7 : #include <tinyformat.h>
8 : #include <univalue.h>
9 : #include <util/fs.h>
10 :
11 : #include <algorithm>
12 : #include <fstream>
13 : #include <iterator>
14 : #include <map>
15 : #include <string>
16 : #include <utility>
17 : #include <vector>
18 :
19 : namespace common {
20 : namespace {
21 :
22 : enum class Source {
23 : FORCED,
24 : COMMAND_LINE,
25 : RW_SETTINGS,
26 : CONFIG_FILE_NETWORK_SECTION,
27 : CONFIG_FILE_DEFAULT_SECTION
28 : };
29 :
30 : //! Merge settings from multiple sources in precedence order:
31 : //! Forced config > command line > read-write settings file > config file network-specific section > config file default section
32 : //!
33 : //! This function is provided with a callback function fn that contains
34 : //! specific logic for how to merge the sources.
35 : template <typename Fn>
36 173939 : static void MergeSettings(const Settings& settings, const std::string& section, const std::string& name, Fn&& fn)
37 : {
38 : // Merge in the forced settings
39 173939 : if (auto* value = FindKey(settings.forced_settings, name)) {
40 3179 : fn(SettingsSpan(*value), Source::FORCED);
41 3179 : }
42 : // Merge in the command-line options
43 173939 : if (auto* values = FindKey(settings.command_line_options, name)) {
44 761 : fn(SettingsSpan(*values), Source::COMMAND_LINE);
45 761 : }
46 : // Merge in the read-write settings
47 173939 : if (const SettingsValue* value = FindKey(settings.rw_settings, name)) {
48 0 : fn(SettingsSpan(*value), Source::RW_SETTINGS);
49 0 : }
50 : // Merge in the network-specific section of the config file
51 173939 : if (!section.empty()) {
52 173192 : if (auto* map = FindKey(settings.ro_config, section)) {
53 0 : if (auto* values = FindKey(*map, name)) {
54 0 : fn(SettingsSpan(*values), Source::CONFIG_FILE_NETWORK_SECTION);
55 0 : }
56 0 : }
57 173192 : }
58 : // Merge in the default section of the config file
59 173939 : if (auto* map = FindKey(settings.ro_config, "")) {
60 0 : if (auto* values = FindKey(*map, name)) {
61 0 : fn(SettingsSpan(*values), Source::CONFIG_FILE_DEFAULT_SECTION);
62 0 : }
63 0 : }
64 173939 : }
65 : } // namespace
66 :
67 10039 : bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& values, std::vector<std::string>& errors)
68 : {
69 10039 : values.clear();
70 10039 : errors.clear();
71 :
72 : // Ok for file to not exist
73 10039 : if (!fs::exists(path)) return true;
74 173 :
75 10039 : std::ifstream file;
76 10039 : file.open(path);
77 10039 : if (!file.is_open()) {
78 0 : errors.emplace_back(strprintf("%s. Please check permissions.", fs::PathToString(path)));
79 0 : return false;
80 : }
81 :
82 10039 : SettingsValue in;
83 10039 : if (!in.read(std::string{std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>()})) {
84 2093 : errors.emplace_back(strprintf("Unable to parse settings file %s", fs::PathToString(path)));
85 2093 : return false;
86 : }
87 :
88 7946 : if (file.fail()) {
89 0 : errors.emplace_back(strprintf("Failed reading settings file %s", fs::PathToString(path)));
90 0 : return false;
91 : }
92 7946 : file.close(); // Done with file descriptor. Release while copying data.
93 :
94 7946 : if (!in.isObject()) {
95 96 : errors.emplace_back(strprintf("Found non-object value %s in settings file %s", in.write(), fs::PathToString(path)));
96 96 : return false;
97 : }
98 :
99 7850 : const std::vector<std::string>& in_keys = in.getKeys();
100 7850 : const std::vector<SettingsValue>& in_values = in.getValues();
101 15690 : for (size_t i = 0; i < in_keys.size(); ++i) {
102 7840 : auto inserted = values.emplace(in_keys[i], in_values[i]);
103 7840 : if (!inserted.second) {
104 0 : errors.emplace_back(strprintf("Found duplicate key %s in settings file %s", in_keys[i], fs::PathToString(path)));
105 0 : values.clear();
106 0 : break;
107 : }
108 7840 : }
109 7850 : return errors.empty();
110 10039 : }
111 :
112 12153 : bool WriteSettings(const fs::path& path,
113 : const std::map<std::string, SettingsValue>& values,
114 : std::vector<std::string>& errors)
115 : {
116 12153 : SettingsValue out(SettingsValue::VOBJ);
117 24306 : for (const auto& value : values) {
118 12153 : out.pushKVEnd(value.first, value.second);
119 : }
120 12153 : std::ofstream file;
121 12153 : file.open(path);
122 12153 : if (file.fail()) {
123 2445 : errors.emplace_back(strprintf("Error: Unable to open settings file %s for writing", fs::PathToString(path)));
124 2445 : return false;
125 : }
126 9708 : file << out.write(/* prettyIndent= */ 4, /* indentLevel= */ 1) << std::endl;
127 9708 : file.close();
128 9708 : return true;
129 12153 : }
130 :
131 172907 : SettingsValue GetSetting(const Settings& settings,
132 : const std::string& section,
133 : const std::string& name,
134 : bool ignore_default_section_config,
135 : bool ignore_nonpersistent,
136 : bool get_chain_type)
137 : {
138 172907 : SettingsValue result;
139 172907 : bool done = false; // Done merging any more settings sources.
140 176640 : MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
141 : // Weird behavior preserved for backwards compatibility: Apply negated
142 : // setting even if non-negated setting would be ignored. A negated
143 : // value in the default section is applied to network specific options,
144 : // even though normal non-negated values there would be ignored.
145 3733 : const bool never_ignore_negated_setting = span.last_negated();
146 :
147 : // Weird behavior preserved for backwards compatibility: Take first
148 : // assigned value instead of last. In general, later settings take
149 : // precedence over early settings, but for backwards compatibility in
150 : // the config file the precedence is reversed for all settings except
151 : // chain type settings.
152 3733 : const bool reverse_precedence =
153 3733 : (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
154 0 : !get_chain_type;
155 :
156 : // Weird behavior preserved for backwards compatibility: Negated
157 : // -regtest and -testnet arguments which you would expect to override
158 : // values set in the configuration file are currently accepted but
159 : // silently ignored. It would be better to apply these just like other
160 : // negated values, or at least warn they are ignored.
161 3733 : const bool skip_negated_command_line = get_chain_type;
162 :
163 3733 : if (done) return;
164 :
165 : // Ignore settings in default config section if requested.
166 3733 : if (ignore_default_section_config && source == Source::CONFIG_FILE_DEFAULT_SECTION &&
167 0 : !never_ignore_negated_setting) {
168 0 : return;
169 : }
170 :
171 : // Ignore nonpersistent settings if requested.
172 3733 : if (ignore_nonpersistent && (source == Source::COMMAND_LINE || source == Source::FORCED)) return;
173 :
174 : // Skip negated command line settings.
175 3733 : if (skip_negated_command_line && span.last_negated()) return;
176 :
177 3733 : if (!span.empty()) {
178 3526 : result = reverse_precedence ? span.begin()[0] : span.end()[-1];
179 3526 : done = true;
180 3733 : } else if (span.last_negated()) {
181 207 : result = false;
182 207 : done = true;
183 207 : }
184 3733 : });
185 172907 : return result;
186 172907 : }
187 :
188 496 : std::vector<SettingsValue> GetSettingsList(const Settings& settings,
189 : const std::string& section,
190 : const std::string& name,
191 : bool ignore_default_section_config)
192 : {
193 496 : std::vector<SettingsValue> result;
194 496 : bool done = false; // Done merging any more settings sources.
195 496 : bool prev_negated_empty = false;
196 703 : MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
197 : // Weird behavior preserved for backwards compatibility: Apply config
198 : // file settings even if negated on command line. Negating a setting on
199 : // command line will ignore earlier settings on the command line and
200 : // ignore settings in the config file, unless the negated command line
201 : // value is followed by non-negated value, in which case config file
202 : // settings will be brought back from the dead (but earlier command
203 : // line settings will still be ignored).
204 207 : const bool add_zombie_config_values =
205 207 : (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
206 0 : !prev_negated_empty;
207 :
208 : // Ignore settings in default config section if requested.
209 207 : if (ignore_default_section_config && source == Source::CONFIG_FILE_DEFAULT_SECTION) return;
210 :
211 : // Add new settings to the result if isn't already complete, or if the
212 : // values are zombies.
213 207 : if (!done || add_zombie_config_values) {
214 414 : for (const auto& value : span) {
215 207 : if (value.isArray()) {
216 0 : result.insert(result.end(), value.getValues().begin(), value.getValues().end());
217 0 : } else {
218 207 : result.push_back(value);
219 : }
220 : }
221 207 : }
222 :
223 : // If a setting was negated, or if a setting was forced, set
224 : // done to true to ignore any later lower priority settings.
225 207 : done |= span.negated() > 0 || source == Source::FORCED;
226 :
227 : // Update the negated and empty state used for the zombie values check.
228 207 : prev_negated_empty |= span.last_negated() && result.empty();
229 207 : });
230 496 : return result;
231 496 : }
232 :
233 536 : bool OnlyHasDefaultSectionSetting(const Settings& settings, const std::string& section, const std::string& name)
234 : {
235 536 : bool has_default_section_setting = false;
236 536 : bool has_other_setting = false;
237 536 : MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
238 0 : if (span.empty()) return;
239 0 : else if (source == Source::CONFIG_FILE_DEFAULT_SECTION) has_default_section_setting = true;
240 0 : else has_other_setting = true;
241 0 : });
242 : // If a value is set in the default section and not explicitly overwritten by the
243 : // user on the command line or in a different section, then we want to enable
244 : // warnings about the value being ignored.
245 536 : return has_default_section_setting && !has_other_setting;
246 : }
247 :
248 761 : SettingsSpan::SettingsSpan(const std::vector<SettingsValue>& vec) noexcept : SettingsSpan(vec.data(), vec.size()) {}
249 207 : const SettingsValue* SettingsSpan::begin() const { return data + negated(); }
250 3733 : const SettingsValue* SettingsSpan::end() const { return data + size; }
251 3733 : bool SettingsSpan::empty() const { return size == 0 || last_negated(); }
252 7880 : bool SettingsSpan::last_negated() const { return size > 0 && data[size - 1].isFalse(); }
253 414 : size_t SettingsSpan::negated() const
254 : {
255 828 : for (size_t i = size; i > 0; --i) {
256 552 : if (data[i - 1].isFalse()) return i; // Return number of negated values (position of last false value)
257 414 : }
258 276 : return 0;
259 414 : }
260 :
261 : } // namespace common
|
