src/shared/conf-parser.h

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