json_script.h

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #ifndef __JSON_SCRIPT_H
  17 #define __JSON_SCRIPT_H
  18
  19 #include "avl.h"
  20 #include "blob.h"
  21 #include "blobmsg.h"
  22 #include "utils.h"
  23
  24 struct json_script_file;
  25
  26 struct json_script_ctx {
  27         struct avl_tree files;
  28         struct blob_buf buf;
  29
  30         uint32_t run_seq;
  31
  32         /*
  33          * handle_command: handle a command that was not recognized by the
  34          * json_script core (required)
  35          *
  36          * @cmd: blobmsg container of the processed command
  37          * @vars: blobmsg container of current run variables
  38          */
  39         void (*handle_command)(struct json_script_ctx *ctx, const char *name,
  40                                struct blob_attr *cmd, struct blob_attr *vars);
  41
  42         /*
  43          * handle_expr: handle an expression that was not recognized by the
  44          * json_script core (optional)
  45          *
  46          * @expr: blobmsg container of the processed expression
  47          * @vars: blobmsg container of current runtime variables
  48          */
  49         int (*handle_expr)(struct json_script_ctx *ctx, const char *name,
  50                            struct blob_attr *expr, struct blob_attr *vars);
  51
  52         /*
  53          * handle_var - look up a variable that's not part of the runtime
  54          * variable set (optional)
  55          */
  56         const char *(*handle_var)(struct json_script_ctx *ctx, const char *name,
  57                                   struct blob_attr *vars);
  58
  59         /*
  60          * handle_file - load a file by filename (optional)
  61          *
  62          * in case of wildcards, it can return a chain of json_script files
  63          * linked via the ::next pointer. Only the first json_script file is
  64          * added to the tree.
  65          */
  66         struct json_script_file *(*handle_file)(struct json_script_ctx *ctx,
  67                                                 const char *name);
  68
  69         /*
  70          * handle_error - handle a processing error in a command or expression
  71          * (optional)
  72          *
  73          * @msg: error message
  74          * @context: source file context of the error (blobmsg container)
  75          */
  76         void (*handle_error)(struct json_script_ctx *ctx, const char *msg,
  77                              struct blob_attr *context);
  78 };
  79
  80 struct json_script_file {
  81         struct avl_node avl;
  82         struct json_script_file *next;
  83
  84         unsigned int seq;
  85         struct blob_attr data[];
  86 };
  87
  88 void json_script_init(struct json_script_ctx *ctx);
  89 void json_script_free(struct json_script_ctx *ctx);
  90
  91 /*
  92  * json_script_run - run a json script with a set of runtime variables
  93  *
  94  * @filename: initial filename to run
  95  * @vars: blobmsg container of the current runtime variables
  96  */
  97 void json_script_run(struct json_script_ctx *ctx, const char *filename,
  98                      struct blob_attr *vars);
  99
 100 struct json_script_file *
 101 json_script_file_from_blobmsg(const char *name, void *data, int len);
 102
 103 /*
 104  * json_script_find_var - helper function to find a runtime variable from
 105  * the list passed by json_script user.
 106  * It is intended to be used by the .handle_var callback
 107  */
 108 const char *json_script_find_var(struct json_script_ctx *ctx, struct blob_attr *vars,
 109                                  const char *name);
 110
 111 #endif