Bitcoin Core  27.99.0
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 <config/bitcoin-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 
21 namespace common {
22 namespace {
23 
24 enum 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
33 const std::string SETTINGS_WARN_MSG_KEY{"_warning_"};
34 
40 template <typename Fn>
41 static 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 
72 bool 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 
87  SettingsValue in;
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 
123 bool 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.", PACKAGE_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 
203 std::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 
248 bool 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 
263 SettingsSpan::SettingsSpan(const std::vector<SettingsValue>& vec) noexcept : SettingsSpan(vec.data(), vec.size()) {}
264 const SettingsValue* SettingsSpan::begin() const { return data + negated(); }
265 const SettingsValue* SettingsSpan::end() const { return data + size; }
266 bool SettingsSpan::empty() const { return size == 0 || last_negated(); }
267 bool SettingsSpan::last_negated() const { return size > 0 && data[size - 1].isFalse(); }
268 size_t SettingsSpan::negated() const
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())
#define PACKAGE_NAME
@ 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:840
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:60
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:1161