ucimap.h

   1 /*
   2  * ucimap.h - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008-2009 Felix Fietkau <nbd@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU Lesser General Public License for more details.
  13  */
  14
  15 /*
  16  * This file contains ucimap, an API for mapping UCI to C data structures
  17  */
  18
  19 #ifndef __UCIMAP_H
  20 #define __UCIMAP_H
  21
  22 #include <stdbool.h>
  23 #include "uci.h"
  24
  25 #ifndef ARRAY_SIZE
  26 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
  27 #endif
  28
  29 #define BITFIELD_SIZE(_fields) (((_fields) / 8) + 1)
  30
  31 #define CLR_BIT(_name, _bit) do { \
  32         _name[(_bit) / 8] &= ~(1 << ((_bit) % 8)); \
  33 } while (0)
  34
  35 #define SET_BIT(_name, _bit) do { \
  36         _name[(_bit) / 8] |=  (1 << ((_bit) % 8)); \
  37 } while (0)
  38
  39 #define TEST_BIT(_name, _bit) \
  40         (_name[(_bit) / 8] & (1 << ((_bit) % 8)))
  41
  42 #ifndef __GNUC__
  43
  44 #define __optmap_gen_type(_type, _field) -1
  45
  46 #ifndef likely
  47 #define likely(_expr) !!(_expr)
  48 #endif
  49
  50 #ifndef unlikely
  51 #define unlikely(_expr) !!(_expr)
  52 #endif
  53
  54 #else /* __GNUC__ */
  55
  56 #define __compatible(_type, _field, _newtype) \
  57         __builtin_types_compatible_p(typeof(&(((_type *)0)->_field)), _newtype *)
  58
  59 #define __list_compatible(_type, _field, __val, __else) \
  60         __builtin_choose_expr(__compatible(_type, _field, struct ucimap_list *), __val, __else)
  61
  62 #define __int_compatible(_type, _field, __val, __else) \
  63         __builtin_choose_expr(__compatible(_type, _field, int), __val, \
  64                 __builtin_choose_expr(__compatible(_type, _field, unsigned int), __val, \
  65                         __else))
  66
  67 #define __string_compatible(_type, _field, __val, __else) \
  68         __builtin_choose_expr(__compatible(_type, _field, char *), __val, \
  69                 __builtin_choose_expr(__compatible(_type, _field, unsigned char *), __val, \
  70                         __builtin_choose_expr(__compatible(_type, _field, const char *), __val, \
  71                                 __builtin_choose_expr(__compatible(_type, _field, const unsigned char *), __val, \
  72                                         __else))))
  73
  74 #define __bool_compatible(_type, _field, __val, __else) \
  75         __builtin_choose_expr(__compatible(_type, _field, bool), __val, __else)
  76
  77
  78 #define __optmap_gen_type(_type, _field) \
  79         __list_compatible(_type, _field, UCIMAP_LIST, \
  80         __int_compatible(_type, _field, UCIMAP_INT, \
  81         __string_compatible(_type, _field, UCIMAP_STRING, \
  82         __bool_compatible(_type, _field, UCIMAP_BOOL, \
  83         -1))))
  84
  85 #ifndef likely
  86 #define likely(x)   __builtin_expect(!!(x), 1)
  87 #endif
  88
  89 #ifndef unlikely
  90 #define unlikely(x) __builtin_expect(!!(x), 0)
  91 #endif
  92
  93 #endif /* __GNUC__ */
  94
  95 #define UCIMAP_OPTION(_type, _field) \
  96         .type = UCIMAP_CUSTOM, \
  97         .name = #_field, \
  98         .offset = offsetof(_type, _field), \
  99         .detected_type = __optmap_gen_type(_type, _field), \
 100         .type_name = #_type
 101
 102
 103 #define UCIMAP_SECTION(_name, _field) \
 104         .alloc_len = sizeof(_name), \
 105         .smap_offset = offsetof(_name, _field), \
 106         .type_name = #_name
 107
 108 struct uci_sectionmap;
 109 struct uci_optmap;
 110
 111 struct ucimap_list;
 112 struct ucimap_fixup;
 113 struct ucimap_alloc;
 114 struct ucimap_alloc_custom;
 115 struct ucimap_section_data;
 116
 117 struct uci_map {
 118         struct uci_sectionmap **sections;
 119         unsigned int n_sections;
 120         bool parsed;
 121         void *priv;
 122
 123         /* private */
 124         struct ucimap_fixup *fixup;
 125         struct ucimap_fixup **fixup_tail;
 126         struct ucimap_section_data *sdata;
 127         struct ucimap_section_data *pending;
 128         struct ucimap_section_data **sdata_tail;
 129 };
 130
 131 enum ucimap_type {
 132         /* types */
 133         UCIMAP_SIMPLE   = 0x00,
 134         UCIMAP_LIST     = 0x10,
 135         UCIMAP_TYPE     = 0xf0, /* type mask */
 136
 137         /* subtypes */
 138         UCIMAP_STRING   = 0x0,
 139         UCIMAP_BOOL     = 0x1,
 140         UCIMAP_INT      = 0x2,
 141         UCIMAP_SECTION  = 0x3,
 142         UCIMAP_CUSTOM   = 0x4,
 143         UCIMAP_SUBTYPE  = 0xf, /* subtype mask */
 144
 145         /* automatically create lists from
 146          * options with space-separated items */
 147         UCIMAP_LIST_AUTO = 0x0100,
 148         UCIMAP_FLAGS     = 0xff00, /* flags mask */
 149 };
 150
 151 union ucimap_data {
 152         int i;
 153         bool b;
 154         char *s;
 155         void *ptr;
 156         void **data;
 157         struct ucimap_list *list;
 158 };
 159
 160 struct ucimap_section_data {
 161         struct uci_map *map;
 162         struct uci_sectionmap *sm;
 163         const char *section_name;
 164
 165         /* map for changed fields */
 166         unsigned char *cmap;
 167         bool done;
 168
 169         /* internal */
 170         struct ucimap_section_data *next, **ref;
 171         struct ucimap_alloc *allocmap;
 172         struct ucimap_alloc_custom *alloc_custom;
 173         unsigned int allocmap_len;
 174         unsigned int alloc_custom_len;
 175 };
 176
 177 struct uci_sectionmap {
 178         /* type string for the uci section */
 179         const char *type;
 180
 181         /* length of the struct to map into, filled in by macro */
 182         unsigned int alloc_len;
 183
 184         /* sectionmap offset, filled in by macro */
 185         unsigned int smap_offset;
 186
 187         /* return a pointer to the section map data (allocate if necessary) */
 188         struct ucimap_section_data *(*alloc)(struct uci_map *map,
 189                 struct uci_sectionmap *sm, struct uci_section *s);
 190
 191         /* give the caller time to initialize the preallocated struct */
 192         int (*init)(struct uci_map *map, void *section, struct uci_section *s);
 193
 194         /* pass the fully processed struct to the callback after the section end */
 195         int (*add)(struct uci_map *map, void *section);
 196
 197         /* let the callback clean up its own stuff in the section */
 198         int (*free)(struct uci_map *map, void *section);
 199
 200         /* list of option mappings for this section */
 201         struct uci_optmap *options;
 202         unsigned int n_options;
 203         unsigned int options_size;
 204
 205         /* internal */
 206         const char *type_name;
 207 };
 208
 209 struct uci_optmap {
 210         unsigned int offset;
 211         const char *name;
 212         enum ucimap_type type;
 213         int (*parse)(void *section, struct uci_optmap *om, union ucimap_data *data, const char *string);
 214         int (*format)(void *section, struct uci_optmap *om, union ucimap_data *data, char **string);
 215         void (*free)(void *section, struct uci_optmap *om, void *ptr);
 216         union {
 217                 struct {
 218                         int base;
 219                         int min;
 220                         int max;
 221                 } i;
 222                 struct {
 223                         int maxlen;
 224                 } s;
 225                 struct uci_sectionmap *sm;
 226         } data;
 227
 228         /* internal */
 229         int detected_type;
 230         const char *type_name;
 231 };
 232
 233 struct ucimap_list {
 234         int n_items;
 235         int size;
 236         union ucimap_data item[];
 237 };
 238
 239 /**
 240  * ucimap_init: initialize the ucimap data structure
 241  * @map: ucimap data structure
 242  *
 243  * you must call this function before doing any other ucimap operation
 244  * on the data structure
 245  */
 246 extern int ucimap_init(struct uci_map *map);
 247
 248 /**
 249  * ucimap_cleanup: clean up all allocated data from ucimap
 250  * @map: ucimap data structure
 251  */
 252 extern void ucimap_cleanup(struct uci_map *map);
 253
 254 /**
 255  * ucimap_parse: parse all sections in an uci package using ucimap
 256  * @map: ucimap data structure
 257  * @pkg: uci package
 258  */
 259 extern void ucimap_parse(struct uci_map *map, struct uci_package *pkg);
 260
 261 /**
 262  * ucimap_set_changed: mark a field in a custom data structure as changed
 263  * @sd: pointer to the ucimap section data
 264  * @field: pointer to the field inside the custom data structure
 265  *
 266  * @sd must be set to the section data inside the data structure that contains @field
 267  */
 268 extern void ucimap_set_changed(struct ucimap_section_data *sd, void *field);
 269
 270 /**
 271  * ucimap_store_section: copy all changed data from the converted data structure to uci
 272  * @map: ucimap data structure
 273  * @p: uci package to store the changes in
 274  * @sd: pointer to the ucimap section data
 275  *
 276  * changes are not saved or committed automatically
 277  */
 278 extern int ucimap_store_section(struct uci_map *map, struct uci_package *p, struct ucimap_section_data *sd);
 279
 280 /**
 281  * ucimap_parse_section: parse a single section
 282  * @map: ucimap data structure
 283  * @sm: uci section map
 284  * @sd: pointer to the ucimap section data
 285  * @s: pointer to the uci section
 286  *
 287  * this function overwrites the ucimap section data, do not use on a section
 288  * that has been parsed already
 289  */
 290 extern int ucimap_parse_section(struct uci_map *map, struct uci_sectionmap *sm, struct ucimap_section_data *sd, struct uci_section *s);
 291
 292 /**
 293  * ucimap_free_section: free a data structure for a converted section
 294  * @map: ucimap data structure
 295  * @sd: pointer to the ucimap section data
 296  *
 297  * this function will clean up all data that was allocated by ucimap for this section.
 298  * all references to the data structure become invalid
 299  */
 300 extern void ucimap_free_section(struct uci_map *map, struct ucimap_section_data *sd);
 301
 302 /**
 303  * ucimap_resize_list: allocate or resize a uci list
 304  * @sd: pointer to the ucimap section data
 305  * @list: pointer to the list field
 306  * @items: new size
 307  *
 308  * @sd must point to the data structure that contains @list.
 309  * @list must point to the field containing a pointer to the list, not the list directly
 310  * the memory allocated for this list is tracked for the section and freed automatically
 311  */
 312 extern int ucimap_resize_list(struct ucimap_section_data *sd, struct ucimap_list **list, int items);
 313
 314 /**
 315  * ucimap_free_item: free the allocated memory for a data structure member
 316  * @sd: pointer to the ucimap section data
 317  * @item: pointer to the field inside the data structure
 318  *
 319  * @sd must point to the data structure that contains @item.
 320  * @item must point to the field containing a pointer to the allocated item
 321  */
 322 extern void ucimap_free_item(struct ucimap_section_data *sd, void *item);
 323
 324 #endif