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, /* Do not warn about unknown non-extension fields */
  18         CONFIG_PARSE_ALLOW_INCLUDE = 1 << 1, /* Allow the deprecated .include stanza */
  19         CONFIG_PARSE_WARN          = 1 << 2, /* 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
  93 int config_parse_many_nulstr(
  94                 const char *conf_file,      /* possibly NULL */
  95                 const char *conf_file_dirs, /* nulstr */
  96                 const char *sections,       /* nulstr */
  97                 ConfigItemLookup lookup,
  98                 const void *table,
  99                 ConfigParseFlags flags,
 100                 void *userdata);
 101
 102 int config_parse_many(
 103                 const char *conf_file,      /* possibly NULL */
 104                 const char* const* conf_file_dirs,
 105                 const char *dropin_dirname,
 106                 const char *sections,       /* nulstr */
 107                 ConfigItemLookup lookup,
 108                 const void *table,
 109                 ConfigParseFlags flags,
 110                 void *userdata,
 111                 char ***ret_dropins);       /* possibly NULL */
 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_int32);
 120 CONFIG_PARSER_PROTOTYPE(config_parse_uint64);
 121 CONFIG_PARSER_PROTOTYPE(config_parse_double);
 122 CONFIG_PARSER_PROTOTYPE(config_parse_iec_size);
 123 CONFIG_PARSER_PROTOTYPE(config_parse_si_uint64);
 124 CONFIG_PARSER_PROTOTYPE(config_parse_iec_uint64);
 125 CONFIG_PARSER_PROTOTYPE(config_parse_bool);
 126 CONFIG_PARSER_PROTOTYPE(config_parse_id128);
 127 CONFIG_PARSER_PROTOTYPE(config_parse_tristate);
 128 CONFIG_PARSER_PROTOTYPE(config_parse_string);
 129 CONFIG_PARSER_PROTOTYPE(config_parse_path);
 130 CONFIG_PARSER_PROTOTYPE(config_parse_strv);
 131 CONFIG_PARSER_PROTOTYPE(config_parse_sec);
 132 CONFIG_PARSER_PROTOTYPE(config_parse_sec_def_infinity);
 133 CONFIG_PARSER_PROTOTYPE(config_parse_sec_def_unset);
 134 CONFIG_PARSER_PROTOTYPE(config_parse_nsec);
 135 CONFIG_PARSER_PROTOTYPE(config_parse_mode);
 136 CONFIG_PARSER_PROTOTYPE(config_parse_warn_compat);
 137 CONFIG_PARSER_PROTOTYPE(config_parse_log_facility);
 138 CONFIG_PARSER_PROTOTYPE(config_parse_log_level);
 139 CONFIG_PARSER_PROTOTYPE(config_parse_signal);
 140 CONFIG_PARSER_PROTOTYPE(config_parse_personality);
 141 CONFIG_PARSER_PROTOTYPE(config_parse_permille);
 142 CONFIG_PARSER_PROTOTYPE(config_parse_ifname);
 143 CONFIG_PARSER_PROTOTYPE(config_parse_ifnames);
 144 CONFIG_PARSER_PROTOTYPE(config_parse_ip_port);
 145 CONFIG_PARSER_PROTOTYPE(config_parse_mtu);
 146 CONFIG_PARSER_PROTOTYPE(config_parse_rlimit);
 147 CONFIG_PARSER_PROTOTYPE(config_parse_vlanprotocol);
 148
 149 typedef enum Disabled {
 150         DISABLED_CONFIGURATION,
 151         DISABLED_LEGACY,
 152         DISABLED_EXPERIMENTAL,
 153 } Disabled;
 154
 155 #define DEFINE_CONFIG_PARSE(function, parser, msg)                      \
 156         CONFIG_PARSER_PROTOTYPE(function) {                             \
 157                 int *i = data, r;                                       \
 158                                                                         \
 159                 assert(filename);                                       \
 160                 assert(lvalue);                                         \
 161                 assert(rvalue);                                         \
 162                 assert(data);                                           \
 163                                                                         \
 164                 r = parser(rvalue);                                     \
 165                 if (r < 0) {                                            \
 166                         log_syntax(unit, LOG_ERR, filename, line, r,    \
 167                                    msg ", ignoring: %s", rvalue);       \
 168                         return 0;                                       \
 169                 }                                                       \
 170                                                                         \
 171                 *i = r;                                                 \
 172                 return 0;                                               \
 173         }
 174
 175 #define DEFINE_CONFIG_PARSE_PTR(function, parser, type, msg)            \
 176         CONFIG_PARSER_PROTOTYPE(function) {                             \
 177                 type *i = data;                                         \
 178                 int r;                                                  \
 179                                                                         \
 180                 assert(filename);                                       \
 181                 assert(lvalue);                                         \
 182                 assert(rvalue);                                         \
 183                 assert(data);                                           \
 184                                                                         \
 185                 r = parser(rvalue, i);                                  \
 186                 if (r < 0)                                              \
 187                         log_syntax(unit, LOG_ERR, filename, line, r,    \
 188                                    msg ", ignoring: %s", rvalue);       \
 189                                                                         \
 190                 return 0;                                               \
 191         }
 192
 193 #define DEFINE_CONFIG_PARSE_ENUM(function, name, type, msg)             \
 194         CONFIG_PARSER_PROTOTYPE(function) {                             \
 195                 type *i = data, x;                                      \
 196                                                                         \
 197                 assert(filename);                                       \
 198                 assert(lvalue);                                         \
 199                 assert(rvalue);                                         \
 200                 assert(data);                                           \
 201                                                                         \
 202                 x = name##_from_string(rvalue);                         \
 203                 if (x < 0) {                                            \
 204                         log_syntax(unit, LOG_ERR, filename, line, 0,    \
 205                                    msg ", ignoring: %s", rvalue);       \
 206                         return 0;                                       \
 207                 }                                                       \
 208                                                                         \
 209                 *i = x;                                                 \
 210                 return 0;                                               \
 211         }
 212
 213 #define DEFINE_CONFIG_PARSE_ENUM_WITH_DEFAULT(function, name, type, default_value, msg) \
 214         CONFIG_PARSER_PROTOTYPE(function) {                             \
 215                 type *i = data, x;                                      \
 216                                                                         \
 217                 assert(filename);                                       \
 218                 assert(lvalue);                                         \
 219                 assert(rvalue);                                         \
 220                 assert(data);                                           \
 221                                                                         \
 222                 if (isempty(rvalue)) {                                  \
 223                         *i = default_value;                             \
 224                         return 0;                                       \
 225                 }                                                       \
 226                                                                         \
 227                 x = name##_from_string(rvalue);                         \
 228                 if (x < 0) {                                            \
 229                         log_syntax(unit, LOG_ERR, filename, line, 0,    \
 230                                    msg ", ignoring: %s", rvalue);       \
 231                         return 0;                                       \
 232                 }                                                       \
 233                                                                         \
 234                 *i = x;                                                 \
 235                 return 0;                                               \
 236         }
 237
 238 #define DEFINE_CONFIG_PARSE_ENUMV(function, name, type, invalid, msg)          \
 239         CONFIG_PARSER_PROTOTYPE(function) {                                    \
 240                 type **enums = data, x, *ys;                                   \
 241                 _cleanup_free_ type *xs = NULL;                                \
 242                 const char *word, *state;                                      \
 243                 size_t l, i = 0;                                               \
 244                                                                                \
 245                 assert(filename);                                              \
 246                 assert(lvalue);                                                \
 247                 assert(rvalue);                                                \
 248                 assert(data);                                                  \
 249                                                                                \
 250                 xs = new0(type, 1);                                            \
 251                 if (!xs)                                                       \
 252                         return -ENOMEM;                                        \
 253                                                                                \
 254                 *xs = invalid;                                                 \
 255                                                                                \
 256                 FOREACH_WORD(word, l, rvalue, state) {                         \
 257                         _cleanup_free_ char *en = NULL;                        \
 258                         type *new_xs;                                          \
 259                                                                                \
 260                         en = strndup(word, l);                                 \
 261                         if (!en)                                               \
 262                                 return -ENOMEM;                                \
 263                                                                                \
 264                         if ((x = name##_from_string(en)) < 0) {                \
 265                                 log_syntax(unit, LOG_ERR, filename, line, 0,   \
 266                                            msg ", ignoring: %s", en);          \
 267                                 continue;                                      \
 268                         }                                                      \
 269                                                                                \
 270                         for (ys = xs; x != invalid && *ys != invalid; ys++) {  \
 271                                 if (*ys == x) {                                \
 272                                         log_syntax(unit, LOG_NOTICE, filename, \
 273                                                    line, 0,                    \
 274                                                    "Duplicate entry, ignoring: %s", \
 275                                                    en);                        \
 276                                         x = invalid;                           \
 277                                 }                                              \
 278                         }                                                      \
 279                                                                                \
 280                         if (x == invalid)                                      \
 281                                 continue;                                      \
 282                                                                                \
 283                         *(xs + i) = x;                                         \
 284                         new_xs = realloc(xs, (++i + 1) * sizeof(type));        \
 285                         if (new_xs)                                            \
 286                                 xs = new_xs;                                   \
 287                         else                                                   \
 288                                 return -ENOMEM;                                \
 289                                                                                \
 290                         *(xs + i) = invalid;                                   \
 291                 }                                                              \
 292                                                                                \
 293                 free_and_replace(*enums, xs);                                  \
 294                 return 0;                                                      \
 295         }