src/shared/conf-parser.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2010 Lennart Poettering
   8 ***/
   9
  10 #include <errno.h>
  11 #include <stdbool.h>
  12 #include <stddef.h>
  13 #include <stdio.h>
  14 #include <syslog.h>
  15
  16 #include "alloc-util.h"
  17 #include "log.h"
  18 #include "macro.h"
  19
  20 /* An abstract parser for simple, line based, shallow configuration files consisting of variable assignments only. */
  21
  22 typedef enum ConfigParseFlags {
  23         CONFIG_PARSE_RELAXED       = 1U << 0,
  24         CONFIG_PARSE_ALLOW_INCLUDE = 1U << 1,
  25         CONFIG_PARSE_WARN          = 1U << 2,
  26         CONFIG_PARSE_REFUSE_BOM    = 1U << 3,
  27 } ConfigParseFlags;
  28
  29 /* Argument list for parsers of specific configuration settings. */
  30 #define CONFIG_PARSER_ARGUMENTS                 \
  31         const char *unit,                       \
  32         const char *filename,                   \
  33         unsigned line,                          \
  34         const char *section,                    \
  35         unsigned section_line,                  \
  36         const char *lvalue,                     \
  37         int ltype,                              \
  38         const char *rvalue,                     \
  39         void *data,                             \
  40         void *userdata
  41
  42 /* Prototype for a parser for a specific configuration setting */
  43 typedef int (*ConfigParserCallback)(CONFIG_PARSER_ARGUMENTS);
  44
  45 /* A macro declaring the a function prototype, following the typedef above, simply because it's so cumbersomely long
  46  * otherwise. (And current emacs gets irritatingly slow when editing files that contain lots of very long function
  47  * prototypes on the same screen…) */
  48 #define CONFIG_PARSER_PROTOTYPE(name) int name(CONFIG_PARSER_ARGUMENTS)
  49
  50 /* Wraps information for parsing a specific configuration variable, to
  51  * be stored in a simple array */
  52 typedef struct ConfigTableItem {
  53         const char *section;            /* Section */
  54         const char *lvalue;             /* Name of the variable */
  55         ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
  56         int ltype;                      /* Distinguish different variables passed to the same callback */
  57         void *data;                     /* Where to store the variable's data */
  58 } ConfigTableItem;
  59
  60 /* Wraps information for parsing a specific configuration variable, to
  61  * be stored in a gperf perfect hashtable */
  62 typedef struct ConfigPerfItem {
  63         const char *section_and_lvalue; /* Section + "." + name of the variable */
  64         ConfigParserCallback parse;     /* Function that is called to parse the variable's value */
  65         int ltype;                      /* Distinguish different variables passed to the same callback */
  66         size_t offset;                  /* Offset where to store data, from the beginning of userdata */
  67 } ConfigPerfItem;
  68
  69 /* Prototype for a low-level gperf lookup function */
  70 typedef const ConfigPerfItem* (*ConfigPerfItemLookup)(const char *section_and_lvalue, unsigned length);
  71
  72 /* Prototype for a generic high-level lookup function */
  73 typedef int (*ConfigItemLookup)(
  74                 const void *table,
  75                 const char *section,
  76                 const char *lvalue,
  77                 ConfigParserCallback *func,
  78                 int *ltype,
  79                 void **data,
  80                 void *userdata);
  81
  82 /* Linear table search implementation of ConfigItemLookup, based on
  83  * ConfigTableItem arrays */
  84 int config_item_table_lookup(const void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
  85
  86 /* gperf implementation of ConfigItemLookup, based on gperf
  87  * ConfigPerfItem tables */
  88 int config_item_perf_lookup(const void *table, const char *section, const char *lvalue, ConfigParserCallback *func, int *ltype, void **data, void *userdata);
  89
  90 int config_parse(
  91                 const char *unit,
  92                 const char *filename,
  93                 FILE *f,
  94                 const char *sections,  /* nulstr */
  95                 ConfigItemLookup lookup,
  96                 const void *table,
  97                 ConfigParseFlags flags,
  98                 void *userdata);
  99
 100 int config_parse_many_nulstr(
 101                 const char *conf_file,      /* possibly NULL */
 102                 const char *conf_file_dirs, /* nulstr */
 103                 const char *sections,       /* nulstr */
 104                 ConfigItemLookup lookup,
 105                 const void *table,
 106                 ConfigParseFlags flags,
 107                 void *userdata);
 108
 109 #if 0 /// UNNEEDED by elogind
 110 int config_parse_many(
 111                 const char *conf_file,      /* possibly NULL */
 112                 const char* const* conf_file_dirs,
 113                 const char *dropin_dirname,
 114                 const char *sections,       /* nulstr */
 115                 ConfigItemLookup lookup,
 116                 const void *table,
 117                 ConfigParseFlags flags,
 118                 void *userdata);
 119 #endif // 0
 120
 121 #if 0 /// UNNEEDED by elogind
 122 #endif // 0
 123 #if 0 /// UNNEEDED by elogind
 124 #endif // 0
 125 #if 0 /// UNNEEDED by elogind
 126 #endif // 0
 127 #if 0 /// UNNEEDED by elogind
 128 #endif // 0
 129 #if 0 /// UNNEEDED by elogind
 130 #endif // 0
 131 #if 0 /// UNNEEDED by elogind
 132 #endif // 0
 133 #if 0 /// UNNEEDED by elogind
 134 #endif // 0
 135 CONFIG_PARSER_PROTOTYPE(config_parse_int);
 136 CONFIG_PARSER_PROTOTYPE(config_parse_unsigned);
 137 CONFIG_PARSER_PROTOTYPE(config_parse_long);
 138 CONFIG_PARSER_PROTOTYPE(config_parse_uint8);
 139 CONFIG_PARSER_PROTOTYPE(config_parse_uint16);
 140 CONFIG_PARSER_PROTOTYPE(config_parse_uint32);
 141 CONFIG_PARSER_PROTOTYPE(config_parse_uint64);
 142 CONFIG_PARSER_PROTOTYPE(config_parse_double);
 143 CONFIG_PARSER_PROTOTYPE(config_parse_iec_size);
 144 CONFIG_PARSER_PROTOTYPE(config_parse_si_size);
 145 CONFIG_PARSER_PROTOTYPE(config_parse_iec_uint64);
 146 CONFIG_PARSER_PROTOTYPE(config_parse_bool);
 147 CONFIG_PARSER_PROTOTYPE(config_parse_tristate);
 148 CONFIG_PARSER_PROTOTYPE(config_parse_string);
 149 CONFIG_PARSER_PROTOTYPE(config_parse_path);
 150 CONFIG_PARSER_PROTOTYPE(config_parse_strv);
 151 CONFIG_PARSER_PROTOTYPE(config_parse_sec);
 152 CONFIG_PARSER_PROTOTYPE(config_parse_nsec);
 153 CONFIG_PARSER_PROTOTYPE(config_parse_mode);
 154 CONFIG_PARSER_PROTOTYPE(config_parse_warn_compat);
 155 CONFIG_PARSER_PROTOTYPE(config_parse_log_facility);
 156 CONFIG_PARSER_PROTOTYPE(config_parse_log_level);
 157 CONFIG_PARSER_PROTOTYPE(config_parse_signal);
 158 CONFIG_PARSER_PROTOTYPE(config_parse_personality);
 159 CONFIG_PARSER_PROTOTYPE(config_parse_ifname);
 160 CONFIG_PARSER_PROTOTYPE(config_parse_ip_port);
 161 CONFIG_PARSER_PROTOTYPE(config_parse_join_controllers);
 162 CONFIG_PARSER_PROTOTYPE(config_parse_mtu);
 163 CONFIG_PARSER_PROTOTYPE(config_parse_rlimit);
 164
 165 typedef enum Disabled {
 166         DISABLED_CONFIGURATION,
 167         DISABLED_LEGACY,
 168         DISABLED_EXPERIMENTAL,
 169 } Disabled;
 170
 171 #define DEFINE_CONFIG_PARSE_ENUM(function,name,type,msg)                \
 172         CONFIG_PARSER_PROTOTYPE(function) {                             \
 173                 type *i = data, x;                                      \
 174                                                                         \
 175                 assert(filename);                                       \
 176                 assert(lvalue);                                         \
 177                 assert(rvalue);                                         \
 178                 assert(data);                                           \
 179                                                                         \
 180                 if ((x = name##_from_string(rvalue)) < 0) {             \
 181                         log_syntax(unit, LOG_ERR, filename, line, -x,   \
 182                                    msg ", ignoring: %s", rvalue);       \
 183                         return 0;                                       \
 184                 }                                                       \
 185                                                                         \
 186                 *i = x;                                                 \
 187                 return 0;                                               \
 188         }
 189
 190 #define DEFINE_CONFIG_PARSE_ENUMV(function,name,type,invalid,msg)              \
 191         CONFIG_PARSER_PROTOTYPE(function) {                                    \
 192                 type **enums = data, x, *ys;                                   \
 193                 _cleanup_free_ type *xs = NULL;                                \
 194                 const char *word, *state;                                      \
 195                 size_t l, i = 0;                                               \
 196                                                                                \
 197                 assert(filename);                                              \
 198                 assert(lvalue);                                                \
 199                 assert(rvalue);                                                \
 200                 assert(data);                                                  \
 201                                                                                \
 202                 xs = new0(type, 1);                                            \
 203                 if (!xs)                                                       \
 204                         return -ENOMEM;                                        \
 205                                                                                \
 206                 *xs = invalid;                                                 \
 207                                                                                \
 208                 FOREACH_WORD(word, l, rvalue, state) {                         \
 209                         _cleanup_free_ char *en = NULL;                        \
 210                         type *new_xs;                                          \
 211                                                                                \
 212                         en = strndup(word, l);                                 \
 213                         if (!en)                                               \
 214                                 return -ENOMEM;                                \
 215                                                                                \
 216                         if ((x = name##_from_string(en)) < 0) {                \
 217                                 log_syntax(unit, LOG_ERR, filename, line,      \
 218                                        -x, msg ", ignoring: %s", en);          \
 219                                 continue;                                      \
 220                         }                                                      \
 221                                                                                \
 222                         for (ys = xs; x != invalid && *ys != invalid; ys++) {  \
 223                                 if (*ys == x) {                                \
 224                                         log_syntax(unit, LOG_ERR, filename,    \
 225                                               line, -x,                        \
 226                                               "Duplicate entry, ignoring: %s", \
 227                                               en);                             \
 228                                         x = invalid;                           \
 229                                 }                                              \
 230                         }                                                      \
 231                                                                                \
 232                         if (x == invalid)                                      \
 233                                 continue;                                      \
 234                                                                                \
 235                         *(xs + i) = x;                                         \
 236                         new_xs = realloc(xs, (++i + 1) * sizeof(type));        \
 237                         if (new_xs)                                            \
 238                                 xs = new_xs;                                   \
 239                         else                                                   \
 240                                 return -ENOMEM;                                \
 241                                                                                \
 242                         *(xs + i) = invalid;                                   \
 243                 }                                                              \
 244                                                                                \
 245                 free(*enums);                                                  \
 246                 *enums = xs;                                                   \
 247                 xs = NULL;                                                     \
 248                                                                                \
 249                 return 0;                                                      \
 250         }