uci_internal.h

   1 /*
   2  * libuci - Library for the Unified Configuration Interface
   3  * Copyright (C) 2008 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 #ifndef __UCI_INTERNAL_H
  16 #define __UCI_INTERNAL_H
  17
  18 #define __private __attribute__((visibility("hidden")))
  19 #define __public
  20
  21 struct uci_parse_context
  22 {
  23         /* error context */
  24         const char *reason;
  25         int line;
  26         int byte;
  27
  28         /* private: */
  29         struct uci_package *package;
  30         struct uci_section *section;
  31         bool merge;
  32         FILE *file;
  33         const char *name;
  34         char *buf;
  35         int bufsz;
  36         int pos;
  37 };
  38 #define pctx_pos(pctx)          ((pctx)->pos)
  39 #define pctx_str(pctx, i)       (&(pctx)->buf[(i)])
  40 #define pctx_cur_str(pctx)      pctx_str(pctx, pctx_pos(pctx))
  41 #define pctx_char(pctx, i)      ((pctx)->buf[(i)])
  42 #define pctx_cur_char(pctx)     pctx_char(pctx, pctx_pos(pctx))
  43
  44 extern const char *uci_confdir;
  45 extern const char *uci_savedir;
  46
  47 __private void *uci_malloc(struct uci_context *ctx, size_t size);
  48 __private void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size);
  49 __private char *uci_strdup(struct uci_context *ctx, const char *str);
  50 __private bool uci_validate_str(const char *str, bool name);
  51 __private void uci_add_delta(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value);
  52 __private void uci_free_delta(struct uci_delta *h);
  53 __private struct uci_package *uci_alloc_package(struct uci_context *ctx, const char *name);
  54
  55 __private FILE *uci_open_stream(struct uci_context *ctx, const char *filename, const char *origfilename, int pos, bool write, bool create);
  56 __private void uci_close_stream(FILE *stream);
  57 __private void uci_getln(struct uci_context *ctx, int offset);
  58
  59 __private void uci_parse_error(struct uci_context *ctx, char *reason);
  60 __private void uci_alloc_parse_context(struct uci_context *ctx);
  61
  62 __private void uci_cleanup(struct uci_context *ctx);
  63 __private struct uci_element *uci_lookup_list(struct uci_list *list, const char *name);
  64 __private void uci_fixup_section(struct uci_context *ctx, struct uci_section *s);
  65 __private void uci_free_package(struct uci_package **package);
  66 __private struct uci_element *uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size);
  67 __private void uci_free_element(struct uci_element *e);
  68 __private struct uci_element *uci_expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete);
  69
  70 __private int uci_load_delta(struct uci_context *ctx, struct uci_package *p, bool flush);
  71
  72 static inline bool uci_validate_package(const char *str)
  73 {
  74         return uci_validate_str(str, false);
  75 }
  76
  77 static inline bool uci_validate_type(const char *str)
  78 {
  79         return uci_validate_str(str, false);
  80 }
  81
  82 static inline bool uci_validate_name(const char *str)
  83 {
  84         return uci_validate_str(str, true);
  85 }
  86
  87 /* initialize a list head/item */
  88 static inline void uci_list_init(struct uci_list *ptr)
  89 {
  90         ptr->prev = ptr;
  91         ptr->next = ptr;
  92 }
  93
  94 /* inserts a new list entry after a given entry */
  95 static inline void uci_list_insert(struct uci_list *list, struct uci_list *ptr)
  96 {
  97         list->next->prev = ptr;
  98         ptr->prev = list;
  99         ptr->next = list->next;
 100         list->next = ptr;
 101 }
 102
 103 /* inserts a new list entry at the tail of the list */
 104 static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
 105 {
 106         /* NB: head->prev points at the tail */
 107         uci_list_insert(head->prev, ptr);
 108 }
 109
 110 static inline void uci_list_del(struct uci_list *ptr)
 111 {
 112         struct uci_list *next, *prev;
 113
 114         next = ptr->next;
 115         prev = ptr->prev;
 116
 117         prev->next = next;
 118         next->prev = prev;
 119
 120         uci_list_init(ptr);
 121 }
 122
 123
 124 extern struct uci_backend uci_file_backend;
 125
 126 #ifdef UCI_PLUGIN_SUPPORT
 127 /**
 128  * uci_add_backend: add an extra backend
 129  * @ctx: uci context
 130  * @name: name of the backend
 131  *
 132  * The default backend is "file", which uses /etc/config for config storage
 133  */
 134 __private int uci_add_backend(struct uci_context *ctx, struct uci_backend *b);
 135
 136 /**
 137  * uci_add_backend: add an extra backend
 138  * @ctx: uci context
 139  * @name: name of the backend
 140  *
 141  * The default backend is "file", which uses /etc/config for config storage
 142  */
 143 __private int uci_del_backend(struct uci_context *ctx, struct uci_backend *b);
 144 #endif
 145
 146 #define UCI_BACKEND(_var, _name, ...)   \
 147 struct uci_backend _var = {             \
 148         .e.list = {                     \
 149                 .next = &_var.e.list,   \
 150                 .prev = &_var.e.list,   \
 151         },                              \
 152         .e.name = _name,                \
 153         .e.type = UCI_TYPE_BACKEND,     \
 154         .ptr = &_var,                   \
 155         __VA_ARGS__                     \
 156 }
 157
 158
 159 /*
 160  * functions for debug and error handling, for internal use only
 161  */
 162
 163 #ifdef UCI_DEBUG
 164 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
 165 #else
 166 #define DPRINTF(...)
 167 #endif
 168
 169 /*
 170  * throw an uci exception and store the error number
 171  * in the context.
 172  */
 173 #define UCI_THROW(ctx, err) do {        \
 174         DPRINTF("Exception: %s in %s, %s:%d\n", #err, __func__, __FILE__, __LINE__); \
 175         longjmp(ctx->trap, err);        \
 176 } while (0)
 177
 178 /*
 179  * store the return address for handling exceptions
 180  * needs to be called in every externally visible library function
 181  *
 182  * NB: this does not handle recursion at all. Calling externally visible
 183  * functions from other uci functions is only allowed at the end of the
 184  * calling function, or by wrapping the function call in UCI_TRAP_SAVE
 185  * and UCI_TRAP_RESTORE.
 186  */
 187 #define UCI_HANDLE_ERR(ctx) do {        \
 188         DPRINTF("ENTER: %s\n", __func__); \
 189         int __val = 0;                  \
 190         if (!ctx)                       \
 191                 return UCI_ERR_INVAL;   \
 192         ctx->err = 0;                   \
 193         if (!ctx->internal && !ctx->nested) \
 194                 __val = setjmp(ctx->trap); \
 195         ctx->internal = false;          \
 196         ctx->nested = false;            \
 197         if (__val) {                    \
 198                 DPRINTF("LEAVE: %s, ret=%d\n", __func__, __val); \
 199                 ctx->err = __val;       \
 200                 return __val;           \
 201         }                               \
 202 } while (0)
 203
 204 /*
 205  * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
 206  * are intercepted and redirected to the label specified in 'handler'
 207  * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
 208  * exception handler is restored
 209  */
 210 #define UCI_TRAP_SAVE(ctx, handler) do {   \
 211         jmp_buf __old_trap;             \
 212         int __val;                      \
 213         memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
 214         __val = setjmp(ctx->trap);      \
 215         if (__val) {                    \
 216                 ctx->err = __val;       \
 217                 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
 218                 goto handler;           \
 219         }
 220 #define UCI_TRAP_RESTORE(ctx)           \
 221         memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
 222 } while(0)
 223
 224 /**
 225  * UCI_INTERNAL: Do an internal call of a public API function
 226  *
 227  * Sets Exception handling to passthrough mode.
 228  * Allows API functions to change behavior compared to public use
 229  */
 230 #define UCI_INTERNAL(func, ctx, ...) do { \
 231         ctx->internal = true;           \
 232         func(ctx, __VA_ARGS__);         \
 233 } while (0)
 234
 235 /**
 236  * UCI_NESTED: Do an normal nested call of a public API function
 237  *
 238  * Sets Exception handling to passthrough mode.
 239  * Allows API functions to change behavior compared to public use
 240  */
 241 #define UCI_NESTED(func, ctx, ...) do { \
 242         ctx->nested = true;             \
 243         func(ctx, __VA_ARGS__);         \
 244 } while (0)
 245
 246
 247 /*
 248  * check the specified condition.
 249  * throw an invalid argument exception if it's false
 250  */
 251 #define UCI_ASSERT(ctx, expr) do {      \
 252         if (!(expr)) {                  \
 253                 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
 254                 UCI_THROW(ctx, UCI_ERR_INVAL);  \
 255         }                               \
 256 } while (0)
 257
 258 #endif