Bitcoin Core 28.99.0
P2P Digital Currency
settings.cpp
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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 <bitcoin-build-config.h> // IWYU pragma: keep
8
9#include <tinyformat.h>
10#include <univalue.h>
11#include <util/fs.h>
12
13#include <algorithm>
14#include <fstream>
15#include <iterator>
16#include <map>
17#include <string>
18#include <utility>
19#include <vector>
20
21namespace common {
22namespace {
23
24enum class Source {
25 FORCED,
26 COMMAND_LINE,
27 RW_SETTINGS,
28 CONFIG_FILE_NETWORK_SECTION,
29 CONFIG_FILE_DEFAULT_SECTION
30};
31
32// Json object key for the auto-generated warning comment
33const std::string SETTINGS_WARN_MSG_KEY{"_warning_"};
34
40template <typename Fn>
41static void MergeSettings(const Settings& settings, const std::string& section, const std::string& name, Fn&& fn)
42{
43 // Merge in the forced settings
44 if (auto* value = FindKey(settings.forced_settings, name)) {
45 fn(SettingsSpan(*value), Source::FORCED);
46 }
47 // Merge in the command-line options
48 if (auto* values = FindKey(settings.command_line_options, name)) {
49 fn(SettingsSpan(*values), Source::COMMAND_LINE);
50 }
51 // Merge in the read-write settings
52 if (const SettingsValue* value = FindKey(settings.rw_settings, name)) {
53 fn(SettingsSpan(*value), Source::RW_SETTINGS);
54 }
55 // Merge in the network-specific section of the config file
56 if (!section.empty()) {
57 if (auto* map = FindKey(settings.ro_config, section)) {
58 if (auto* values = FindKey(*map, name)) {
59 fn(SettingsSpan(*values), Source::CONFIG_FILE_NETWORK_SECTION);
60 }
61 }
62 }
63 // Merge in the default section of the config file
64 if (auto* map = FindKey(settings.ro_config, "")) {
65 if (auto* values = FindKey(*map, name)) {
66 fn(SettingsSpan(*values), Source::CONFIG_FILE_DEFAULT_SECTION);
67 }
68 }
69}
70} // namespace
71
72bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& values, std::vector<std::string>& errors)
73{
74 values.clear();
75 errors.clear();
76
77 // Ok for file to not exist
78 if (!fs::exists(path)) return true;
79
80 std::ifstream file;
81 file.open(path);
82 if (!file.is_open()) {
83 errors.emplace_back(strprintf("%s. Please check permissions.", fs::PathToString(path)));
84 return false;
85 }
86
88 if (!in.read(std::string{std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>()})) {
89 errors.emplace_back(strprintf("Settings file %s does not contain valid JSON. This is probably caused by disk corruption or a crash, "
90 "and can be fixed by removing the file, which will reset settings to default values.",
91 fs::PathToString(path)));
92 return false;
93 }
94
95 if (file.fail()) {
96 errors.emplace_back(strprintf("Failed reading settings file %s", fs::PathToString(path)));
97 return false;
98 }
99 file.close(); // Done with file descriptor. Release while copying data.
100
101 if (!in.isObject()) {
102 errors.emplace_back(strprintf("Found non-object value %s in settings file %s", in.write(), fs::PathToString(path)));
103 return false;
104 }
105
106 const std::vector<std::string>& in_keys = in.getKeys();
107 const std::vector<SettingsValue>& in_values = in.getValues();
108 for (size_t i = 0; i < in_keys.size(); ++i) {
109 auto inserted = values.emplace(in_keys[i], in_values[i]);
110 if (!inserted.second) {
111 errors.emplace_back(strprintf("Found duplicate key %s in settings file %s", in_keys[i], fs::PathToString(path)));
112 values.clear();
113 break;
114 }
115 }
116
117 // Remove auto-generated warning comment from the accessible settings.
118 values.erase(SETTINGS_WARN_MSG_KEY);
119
120 return errors.empty();
121}
122
123bool WriteSettings(const fs::path& path,
124 const std::map<std::string, SettingsValue>& values,
125 std::vector<std::string>& errors)
126{
128 // Add auto-generated warning comment
129 out.pushKV(SETTINGS_WARN_MSG_KEY, strprintf("This file is automatically generated and updated by %s. Please do not edit this file while the node "
130 "is running, as any changes might be ignored or overwritten.", CLIENT_NAME));
131 // Push settings values
132 for (const auto& value : values) {
133 out.pushKVEnd(value.first, value.second);
134 }
135 std::ofstream file;
136 file.open(path);
137 if (file.fail()) {
138 errors.emplace_back(strprintf("Error: Unable to open settings file %s for writing", fs::PathToString(path)));
139 return false;
140 }
141 file << out.write(/* prettyIndent= */ 4, /* indentLevel= */ 1) << std::endl;
142 file.close();
143 return true;
144}
145
147 const std::string& section,
148 const std::string& name,
149 bool ignore_default_section_config,
150 bool ignore_nonpersistent,
151 bool get_chain_type)
152{
153 SettingsValue result;
154 bool done = false; // Done merging any more settings sources.
155 MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
156 // Weird behavior preserved for backwards compatibility: Apply negated
157 // setting even if non-negated setting would be ignored. A negated
158 // value in the default section is applied to network specific options,
159 // even though normal non-negated values there would be ignored.
160 const bool never_ignore_negated_setting = span.last_negated();
161
162 // Weird behavior preserved for backwards compatibility: Take first
163 // assigned value instead of last. In general, later settings take
164 // precedence over early settings, but for backwards compatibility in
165 // the config file the precedence is reversed for all settings except
166 // chain type settings.
167 const bool reverse_precedence =
168 (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
169 !get_chain_type;
170
171 // Weird behavior preserved for backwards compatibility: Negated
172 // -regtest and -testnet arguments which you would expect to override
173 // values set in the configuration file are currently accepted but
174 // silently ignored. It would be better to apply these just like other
175 // negated values, or at least warn they are ignored.
176 const bool skip_negated_command_line = get_chain_type;
177
178 if (done) return;
179
180 // Ignore settings in default config section if requested.
181 if (ignore_default_section_config && source == Source::CONFIG_FILE_DEFAULT_SECTION &&
182 !never_ignore_negated_setting) {
183 return;
184 }
185
186 // Ignore nonpersistent settings if requested.
187 if (ignore_nonpersistent && (source == Source::COMMAND_LINE || source == Source::FORCED)) return;
188
189 // Skip negated command line settings.
190 if (skip_negated_command_line && span.last_negated()) return;
191
192 if (!span.empty()) {
193 result = reverse_precedence ? span.begin()[0] : span.end()[-1];
194 done = true;
195 } else if (span.last_negated()) {
196 result = false;
197 done = true;
198 }
199 });
200 return result;
201}
202
203std::vector<SettingsValue> GetSettingsList(const Settings& settings,
204 const std::string& section,
205 const std::string& name,
206 bool ignore_default_section_config)
207{
208 std::vector<SettingsValue> result;
209 bool done = false; // Done merging any more settings sources.
210 bool prev_negated_empty = false;
211 MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
212 // Weird behavior preserved for backwards compatibility: Apply config
213 // file settings even if negated on command line. Negating a setting on
214 // command line will ignore earlier settings on the command line and
215 // ignore settings in the config file, unless the negated command line
216 // value is followed by non-negated value, in which case config file
217 // settings will be brought back from the dead (but earlier command
218 // line settings will still be ignored).
219 const bool add_zombie_config_values =
220 (source == Source::CONFIG_FILE_NETWORK_SECTION || source == Source::CONFIG_FILE_DEFAULT_SECTION) &&
221 !prev_negated_empty;
222
223 // Ignore settings in default config section if requested.
224 if (ignore_default_section_config && source == Source::CONFIG_FILE_DEFAULT_SECTION) return;
225
226 // Add new settings to the result if isn't already complete, or if the
227 // values are zombies.
228 if (!done || add_zombie_config_values) {
229 for (const auto& value : span) {
230 if (value.isArray()) {
231 result.insert(result.end(), value.getValues().begin(), value.getValues().end());
232 } else {
233 result.push_back(value);
234 }
235 }
236 }
237
238 // If a setting was negated, or if a setting was forced, set
239 // done to true to ignore any later lower priority settings.
240 done |= span.negated() > 0 || source == Source::FORCED;
241
242 // Update the negated and empty state used for the zombie values check.
243 prev_negated_empty |= span.last_negated() && result.empty();
244 });
245 return result;
246}
247
248bool OnlyHasDefaultSectionSetting(const Settings& settings, const std::string& section, const std::string& name)
249{
250 bool has_default_section_setting = false;
251 bool has_other_setting = false;
252 MergeSettings(settings, section, name, [&](SettingsSpan span, Source source) {
253 if (span.empty()) return;
254 else if (source == Source::CONFIG_FILE_DEFAULT_SECTION) has_default_section_setting = true;
255 else has_other_setting = true;
256 });
257 // If a value is set in the default section and not explicitly overwritten by the
258 // user on the command line or in a different section, then we want to enable
259 // warnings about the value being ignored.
260 return has_default_section_setting && !has_other_setting;
261}
262
263SettingsSpan::SettingsSpan(const std::vector<SettingsValue>& vec) noexcept : SettingsSpan(vec.data(), vec.size()) {}
264const SettingsValue* SettingsSpan::begin() const { return data + negated(); }
265const SettingsValue* SettingsSpan::end() const { return data + size; }
266bool SettingsSpan::empty() const { return size == 0 || last_negated(); }
267bool SettingsSpan::last_negated() const { return size > 0 && data[size - 1].isFalse(); }
269{
270 for (size_t i = size; i > 0; --i) {
271 if (data[i - 1].isFalse()) return i; // Return number of negated values (position of last false value)
272 }
273 return 0;
274}
275
276} // namespace common
if(!SetupNetworking())
@ VOBJ
Definition: univalue.h:24
std::string write(unsigned int prettyIndent=0, unsigned int indentLevel=0) const
const std::vector< UniValue > & getValues() const
const std::vector< std::string > & getKeys() const
bool read(std::string_view raw)
bool isFalse() const
Definition: univalue.h:81
bool isObject() const
Definition: univalue.h:86
Path class wrapper to block calls to the fs::path(std::string) implicit constructor and the fs::path:...
Definition: fs.h:33
Definition: args.cpp:868
bool WriteSettings(const fs::path &path, const std::map< std::string, SettingsValue > &values, std::vector< std::string > &errors)
Write settings file.
Definition: settings.cpp:123
bool ReadSettings(const fs::path &path, std::map< std::string, SettingsValue > &values, std::vector< std::string > &errors)
Read settings file.
Definition: settings.cpp:72
SettingsValue GetSetting(const Settings &settings, const std::string &section, const std::string &name, bool ignore_default_section_config, bool ignore_nonpersistent, bool get_chain_type)
Get settings value from combined sources: forced settings, command line arguments,...
Definition: settings.cpp:146
auto FindKey(Map &&map, Key &&key) -> decltype(&map.at(key))
Map lookup helper.
Definition: settings.h:107
std::vector< SettingsValue > GetSettingsList(const Settings &settings, const std::string &section, const std::string &name, bool ignore_default_section_config)
Get combined setting value similar to GetSetting(), except if setting was specified multiple times,...
Definition: settings.cpp:203
bool OnlyHasDefaultSectionSetting(const Settings &settings, const std::string &section, const std::string &name)
Return true if a setting is set in the default config file section, and not overridden by a higher pr...
Definition: settings.cpp:248
UniValue SettingsValue
Settings value type (string/integer/boolean/null variant).
Definition: settings.h:28
static bool exists(const path &p)
Definition: fs.h:89
static std::string PathToString(const path &path)
Convert path object to a byte string.
Definition: fs.h:151
const char * name
Definition: rest.cpp:49
const char * source
Definition: rpcconsole.cpp:62
static const int64_t values[]
A selection of numbers that do not trigger int64_t overflow when added/subtracted.
Stored settings.
Definition: settings.h:32
Accessor for list of settings that skips negated values when iterated over.
Definition: settings.h:90
bool last_negated() const
True if the last value is negated.
Definition: settings.cpp:267
const SettingsValue * begin() const
Pointer to first non-negated value.
Definition: settings.cpp:264
const SettingsValue * end() const
Pointer to end of values.
Definition: settings.cpp:265
bool empty() const
True if there are any non-negated values.
Definition: settings.cpp:266
size_t negated() const
Number of negated values.
Definition: settings.cpp:268
const SettingsValue * data
Definition: settings.h:101
#define strprintf
Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for...
Definition: tinyformat.h:1165