src/shared/conf-parser.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <errno.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <syslog.h>
   9
  10 #include "alloc-util.h"
  11 #include "log.h"
  12 #include "macro.h"
  13 #include "time-util.h"
  14
  15 /* An abstract parser for simple, line based, shallow configuration files consisting of variable assignments only. */
  16
  17 typedef enum ConfigParseFlags {
  18         CONFIG_PARSE_RELAXED       = 1 << 0, /* Do not warn about unknown non-extension fields */
  19         CONFIG_PARSE_WARN          = 1 << 1, /* Emit non-debug messages */
  20 } ConfigParseFlags;
  21
  22 /* Argument list for parsers of specific configuration settings. */
  23 #define CONFIG_PARSER_ARGUMENTS                 \
  24         const char *unit,                       \
  25         const char *filename,                   \
  26         unsigned line,                          \
  27         const char *section,                    \
  28         unsigned section_line,                  \
  29         const char *lvalue,                     \
  30         int ltype,                              \
  31         const char *rvalue,                     \
  32         void *data,                             \
  33         void *userdata
  34
  35 /* Prototype for a parser for a specific configuration setting */
  36 typedef int (*ConfigParserCallback)(CONFIG_PARSER_ARGUMENTS);
  37
  38 /* A macro declaring the a function prototype, following the typedef above, simply because it's so cumbersomely long
  39  * otherwise. (And current emacs gets irritatingly slow when editing files that contain lots of very long function
  40  * prototypes on the same screen…) */
  41 #define CONFIG_PARSER_PROTOTYPE(name) int name(CONFIG_PARSER_ARGUMENTS)
  42
  43 /* Wraps information for parsing a specific configuration variable, to
  44  * be stored in a simple array */
  45 typedef struct ConfigTableItem {
  46         const char *section;            /* Section */
  47         const char *lvalue;             /* Name of the variable */
  48         ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
  49         int ltype;                      /* Distinguish different variables passed to the same callback */
  50         void *data;                     /* Where to store the variable's data */
  51 } ConfigTableItem;
  52
  53 /* Wraps information for parsing a specific configuration variable, to
  54  * be stored in a gperf perfect hashtable */
  55 typedef struct ConfigPerfItem {
  56         const char *section_and_lvalue; /* Section + "." + name of the variable */
  57         ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
  58         int ltype;                      /* Distinguish different variables passed to the same callback */
  59         size_t offset;                  /* Offset where to store data, from the beginning of userdata */
  60 } ConfigPerfItem;
  61
  62 /* Prototype for a low-level gperf lookup function */
  63 typedef const ConfigPerfItem* (*ConfigPerfItemLookup)(const char *section_and_lvalue, unsigned length);
  64
  65 /* Prototype for a generic high-level lookup function */
  66 typedef int (*ConfigItemLookup)(
  67                 const void *table,
  68                 const char *section,
  69                 const char *lvalue,
  70                 ConfigParserCallback *func,
  71                 int *ltype,
  72                 void **data,
  73                 void *userdata);
  74
  75 /* Linear table search implementation of ConfigItemLookup, based on
  76  * ConfigTableItem arrays */
  77 int config_item_table_lookup(const void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
  78
  79 /* gperf implementation of ConfigItemLookup, based on gperf
  80  * ConfigPerfItem tables */
  81 int config_item_perf_lookup(const void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
  82
  83 int config_parse(
  84                 const char *unit,
  85                 const char *filename,
  86                 FILE *f,
  87                 const char *sections,       /* nulstr */
  88                 ConfigItemLookup lookup,
  89                 const void *table,
  90                 ConfigParseFlags flags,
  91                 void *userdata,
  92                 usec_t *ret_mtime);         /* possibly NULL */
  93
  94 int config_parse_many_nulstr(
  95                 const char *conf_file,      /* possibly NULL */
  96                 const char *conf_file_dirs, /* nulstr */
  97                 const char *sections,       /* nulstr */
  98                 ConfigItemLookup lookup,
  99                 const void *table,
 100                 ConfigParseFlags flags,
 101                 void *userdata,
 102                 usec_t *ret_mtime);         /* possibly NULL */
 103
 104 int config_parse_many(
 105                 const char *conf_file,      /* possibly NULL */
 106                 const char* const* conf_file_dirs,
 107                 const char *dropin_dirname,
 108                 const char *sections,       /* nulstr */
 109                 ConfigItemLookup lookup,
 110                 const void *table,
 111                 ConfigParseFlags flags,
 112                 void *userdata,
 113                 usec_t *ret_mtime);         /* possibly NULL */
 114
 115 CONFIG_PARSER_PROTOTYPE(config_parse_int);
 116 CONFIG_PARSER_PROTOTYPE(config_parse_unsigned);
 117 CONFIG_PARSER_PROTOTYPE(config_parse_long);
 118 CONFIG_PARSER_PROTOTYPE(config_parse_uint8);
 119 CONFIG_PARSER_PROTOTYPE(config_parse_uint16);
 120 CONFIG_PARSER_PROTOTYPE(config_parse_uint32);
 121 CONFIG_PARSER_PROTOTYPE(config_parse_int32);
 122 CONFIG_PARSER_PROTOTYPE(config_parse_uint64);
 123 CONFIG_PARSER_PROTOTYPE(config_parse_double);
 124 CONFIG_PARSER_PROTOTYPE(config_parse_iec_size);
 125 CONFIG_PARSER_PROTOTYPE(config_parse_si_uint64);
 126 CONFIG_PARSER_PROTOTYPE(config_parse_iec_uint64);
 127 CONFIG_PARSER_PROTOTYPE(config_parse_bool);
 128 CONFIG_PARSER_PROTOTYPE(config_parse_id128);
 129 CONFIG_PARSER_PROTOTYPE(config_parse_tristate);
 130 CONFIG_PARSER_PROTOTYPE(config_parse_string);
 131 CONFIG_PARSER_PROTOTYPE(config_parse_path);
 132 CONFIG_PARSER_PROTOTYPE(config_parse_strv);
 133 CONFIG_PARSER_PROTOTYPE(config_parse_sec);
 134 CONFIG_PARSER_PROTOTYPE(config_parse_sec_def_infinity);
 135 CONFIG_PARSER_PROTOTYPE(config_parse_sec_def_unset);
 136 CONFIG_PARSER_PROTOTYPE(config_parse_nsec);
 137 CONFIG_PARSER_PROTOTYPE(config_parse_mode);
 138 CONFIG_PARSER_PROTOTYPE(config_parse_warn_compat);
 139 CONFIG_PARSER_PROTOTYPE(config_parse_log_facility);
 140 CONFIG_PARSER_PROTOTYPE(config_parse_log_level);
 141 CONFIG_PARSER_PROTOTYPE(config_parse_signal);
 142 CONFIG_PARSER_PROTOTYPE(config_parse_personality);
 143 CONFIG_PARSER_PROTOTYPE(config_parse_permille);
 144 CONFIG_PARSER_PROTOTYPE(config_parse_ifname);
 145 CONFIG_PARSER_PROTOTYPE(config_parse_ifnames);
 146 CONFIG_PARSER_PROTOTYPE(config_parse_ip_port);
 147 CONFIG_PARSER_PROTOTYPE(config_parse_mtu);
 148 CONFIG_PARSER_PROTOTYPE(config_parse_rlimit);
 149 CONFIG_PARSER_PROTOTYPE(config_parse_vlanprotocol);
 150 CONFIG_PARSER_PROTOTYPE(config_parse_percent);
 151
 152 typedef enum Disabled {
 153         DISABLED_CONFIGURATION,
 154         DISABLED_LEGACY,
 155         DISABLED_EXPERIMENTAL,
 156 } Disabled;
 157
 158 #define DEFINE_CONFIG_PARSE(function, parser, msg)                      \
 159         CONFIG_PARSER_PROTOTYPE(function) {                             \
 160                 int *i = data, r;                                       \
 161                                                                         \
 162                 assert(filename);                                       \
 163                 assert(lvalue);                                         \
 164                 assert(rvalue);                                         \
 165                 assert(data);                                           \
 166                                                                         \
 167                 r = parser(rvalue);                                     \
 168                 if (r < 0) {                                            \
 169                         log_syntax(unit, LOG_WARNING, filename, line, r, \
 170                                    msg ", ignoring: %s", rvalue);       \
 171                         return 0;                                       \
 172                 }                                                       \
 173                                                                         \
 174                 *i = r;                                                 \
 175                 return 0;                                               \
 176         }
 177
 178 #define DEFINE_CONFIG_PARSE_PTR(function, parser, type, msg)            \
 179         CONFIG_PARSER_PROTOTYPE(function) {                             \
 180                 type *i = data;                                         \
 181                 int r;                                                  \
 182                                                                         \
 183                 assert(filename);                                       \
 184                 assert(lvalue);                                         \
 185                 assert(rvalue);                                         \
 186                 assert(data);                                           \
 187                                                                         \
 188                 r = parser(rvalue, i);                                  \
 189                 if (r < 0)                                              \
 190                         log_syntax(unit, LOG_WARNING, filename, line, r, \
 191                                    msg ", ignoring: %s", rvalue);       \
 192                                                                         \
 193                 return 0;                                               \
 194         }
 195
 196 #define DEFINE_CONFIG_PARSE_ENUM_FULL(function, from_string, type, msg) \
 197         CONFIG_PARSER_PROTOTYPE(function) {                             \
 198                 type *i = data, x;                                      \
 199                                                                         \
 200                 assert(filename);                                       \
 201                 assert(lvalue);                                         \
 202                 assert(rvalue);                                         \
 203                 assert(data);                                           \
 204                                                                         \
 205                 x = from_string(rvalue);                                \
 206                 if (x < 0) {                                            \
 207                         log_syntax(unit, LOG_WARNING, filename, line, 0, \
 208                                    msg ", ignoring: %s", rvalue);       \
 209                         return 0;                                       \
 210                 }                                                       \
 211                                                                         \
 212                 *i = x;                                                 \
 213                 return 0;                                               \
 214         }
 215
 216 #define DEFINE_CONFIG_PARSE_ENUM(function, name, type, msg)             \
 217         DEFINE_CONFIG_PARSE_ENUM_FULL(function, name##_from_string, type, msg)
 218
 219 #define DEFINE_CONFIG_PARSE_ENUM_WITH_DEFAULT(function, name, type, default_value, msg) \
 220         CONFIG_PARSER_PROTOTYPE(function) {                             \
 221                 type *i = data, x;                                      \
 222                                                                         \
 223                 assert(filename);                                       \
 224                 assert(lvalue);                                         \
 225                 assert(rvalue);                                         \
 226                 assert(data);                                           \
 227                                                                         \
 228                 if (isempty(rvalue)) {                                  \
 229                         *i = default_value;                             \
 230                         return 0;                                       \
 231                 }                                                       \
 232                                                                         \
 233                 x = name##_from_string(rvalue);                         \
 234                 if (x < 0) {                                            \
 235                         log_syntax(unit, LOG_WARNING, filename, line, 0, \
 236                                    msg ", ignoring: %s", rvalue);       \
 237                         return 0;                                       \
 238                 }                                                       \
 239                                                                         \
 240                 *i = x;                                                 \
 241                 return 0;                                               \
 242         }
 243
 244 #define DEFINE_CONFIG_PARSE_ENUMV(function, name, type, invalid, msg)          \
 245         CONFIG_PARSER_PROTOTYPE(function) {                                    \
 246                 type **enums = data;                                           \
 247                 _cleanup_free_ type *xs = NULL;                                \
 248                 size_t i = 0;                                                  \
 249                 int r;                                                         \
 250                                                                                \
 251                 assert(filename);                                              \
 252                 assert(lvalue);                                                \
 253                 assert(rvalue);                                                \
 254                 assert(data);                                                  \
 255                                                                                \
 256                 xs = new0(type, 1);                                            \
 257                 if (!xs)                                                       \
 258                         return -ENOMEM;                                        \
 259                                                                                \
 260                 *xs = invalid;                                                 \
 261                                                                                \
 262                 for (const char *p = rvalue;;) {                               \
 263                         _cleanup_free_ char *en = NULL;                        \
 264                         type x, *new_xs;                                       \
 265                                                                                \
 266                         r = extract_first_word(&p, &en, NULL, 0);              \
 267                         if (r == -ENOMEM)                                      \
 268                                 return log_oom();                              \
 269                         if (r < 0)                                             \
 270                                 return log_syntax(unit, LOG_ERR, filename, line, 0,   \
 271                                                   msg ": %s", en);             \
 272                         if (r == 0)                                            \
 273                                 break;                                         \
 274                                                                                \
 275                         if ((x = name##_from_string(en)) < 0) {                \
 276                                 log_syntax(unit, LOG_WARNING, filename, line, 0,        \
 277                                            msg ", ignoring: %s", en);          \
 278                                 continue;                                      \
 279                         }                                                      \
 280                                                                                \
 281                         for (type *ys = xs; x != invalid && *ys != invalid; ys++)       \
 282                                 if (*ys == x) {                                         \
 283                                         log_syntax(unit, LOG_NOTICE, filename, line, 0, \
 284                                                    "Duplicate entry, ignoring: %s",     \
 285                                                    en);                        \
 286                                         x = invalid;                           \
 287                                 }                                              \
 288                                                                                \
 289                         if (x == invalid)                                      \
 290                                 continue;                                      \
 291                                                                                \
 292                         *(xs + i) = x;                                         \
 293                         new_xs = realloc(xs, (++i + 1) * sizeof(type));        \
 294                         if (new_xs)                                            \
 295                                 xs = new_xs;                                   \
 296                         else                                                   \
 297                                 return log_oom();                              \
 298                                                                                \
 299                         *(xs + i) = invalid;                                   \
 300                 }                                                              \
 301                                                                                \
 302                 return free_and_replace(*enums, xs);                           \
 303         }