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 General Public License for more details.
  13  */
  14
  15 #ifndef __UCI_INTERNAL_H
  16 #define __UCI_INTERNAL_H
  17
  18 #define __public
  19 #ifdef UCI_PLUGIN_SUPPORT
  20 #define __plugin extern
  21 #else
  22 #define __plugin static
  23 #endif
  24
  25 struct uci_parse_context
  26 {
  27         /* error context */
  28         const char *reason;
  29         int line;
  30         int byte;
  31
  32         /* private: */
  33         struct uci_package *package;
  34         struct uci_section *section;
  35         bool merge;
  36         FILE *file;
  37         const char *name;
  38         char *buf;
  39         int bufsz;
  40 };
  41
  42 __plugin void *uci_malloc(struct uci_context *ctx, size_t size);
  43 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size);
  44 __plugin char *uci_strdup(struct uci_context *ctx, const char *str);
  45 __plugin bool uci_validate_str(const char *str, bool name);
  46 __plugin void uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value);
  47 __plugin void uci_free_history(struct uci_history *h);
  48 __plugin struct uci_package *uci_alloc_package(struct uci_context *ctx, const char *name);
  49
  50 #ifdef UCI_PLUGIN_SUPPORT
  51 /**
  52  * uci_add_backend: add an extra backend
  53  * @ctx: uci context
  54  * @name: name of the backend
  55  *
  56  * The default backend is "file", which uses /etc/config for config storage
  57  */
  58 __plugin int uci_add_backend(struct uci_context *ctx, struct uci_backend *b);
  59
  60 /**
  61  * uci_add_backend: add an extra backend
  62  * @ctx: uci context
  63  * @name: name of the backend
  64  *
  65  * The default backend is "file", which uses /etc/config for config storage
  66  */
  67 __plugin int uci_del_backend(struct uci_context *ctx, struct uci_backend *b);
  68 #endif
  69
  70 #define UCI_BACKEND(_var, _name, ...)   \
  71 struct uci_backend _var = {             \
  72         .e.list = {                     \
  73                 .next = &_var.e.list,   \
  74                 .prev = &_var.e.list,   \
  75         },                              \
  76         .e.name = _name,                \
  77         .e.type = UCI_TYPE_BACKEND,     \
  78         .ptr = &_var,                   \
  79         __VA_ARGS__                     \
  80 }
  81
  82
  83 /*
  84  * functions for debug and error handling, for internal use only
  85  */
  86
  87 #ifdef UCI_DEBUG
  88 #define DPRINTF(...) fprintf(stderr, __VA_ARGS__)
  89 #else
  90 #define DPRINTF(...)
  91 #endif
  92
  93 /*
  94  * throw an uci exception and store the error number
  95  * in the context.
  96  */
  97 #define UCI_THROW(ctx, err) do {        \
  98         DPRINTF("Exception: %s in %s, %s:%d\n", #err, __func__, __FILE__, __LINE__); \
  99         longjmp(ctx->trap, err);        \
 100 } while (0)
 101
 102 /*
 103  * store the return address for handling exceptions
 104  * needs to be called in every externally visible library function
 105  *
 106  * NB: this does not handle recursion at all. Calling externally visible
 107  * functions from other uci functions is only allowed at the end of the
 108  * calling function, or by wrapping the function call in UCI_TRAP_SAVE
 109  * and UCI_TRAP_RESTORE.
 110  */
 111 #define UCI_HANDLE_ERR(ctx) do {        \
 112         DPRINTF("ENTER: %s\n", __func__); \
 113         int __val = 0;                  \
 114         ctx->err = 0;                   \
 115         if (!ctx)                       \
 116                 return UCI_ERR_INVAL;   \
 117         if (!ctx->internal)             \
 118                 __val = setjmp(ctx->trap); \
 119         ctx->internal = false;          \
 120         if (__val) {                    \
 121                 DPRINTF("LEAVE: %s, ret=%d\n", __func__, __val); \
 122                 ctx->err = __val;       \
 123                 return __val;           \
 124         }                               \
 125 } while (0)
 126
 127 /*
 128  * In a block enclosed by UCI_TRAP_SAVE and UCI_TRAP_RESTORE, all exceptions
 129  * are intercepted and redirected to the label specified in 'handler'
 130  * after UCI_TRAP_RESTORE, or when reaching the 'handler' label, the old
 131  * exception handler is restored
 132  */
 133 #define UCI_TRAP_SAVE(ctx, handler) do {   \
 134         jmp_buf __old_trap;             \
 135         int __val;                      \
 136         memcpy(__old_trap, ctx->trap, sizeof(ctx->trap)); \
 137         __val = setjmp(ctx->trap);      \
 138         if (__val) {                    \
 139                 ctx->err = __val;       \
 140                 memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
 141                 goto handler;           \
 142         }
 143 #define UCI_TRAP_RESTORE(ctx)           \
 144         memcpy(ctx->trap, __old_trap, sizeof(ctx->trap)); \
 145 } while(0)
 146
 147 /**
 148  * UCI_INTERNAL: Do an internal call of a public API function
 149  *
 150  * Sets Exception handling to passthrough mode.
 151  * Allows API functions to change behavior compared to public use
 152  */
 153 #define UCI_INTERNAL(func, ctx, ...) do { \
 154         ctx->internal = true;           \
 155         func(ctx, __VA_ARGS__);         \
 156 } while (0)
 157
 158 /*
 159  * check the specified condition.
 160  * throw an invalid argument exception if it's false
 161  */
 162 #define UCI_ASSERT(ctx, expr) do {      \
 163         if (!(expr)) {                  \
 164                 DPRINTF("[%s:%d] Assertion failed\n", __FILE__, __LINE__); \
 165                 UCI_THROW(ctx, UCI_ERR_INVAL);  \
 166         }                               \
 167 } while (0)
 168
 169 #endif