func_realtime.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005-2006, BJ Weschke. All rights reserved.
 *
 * BJ Weschke <[email protected]>
 *
 * This code is released by the author with no restrictions on usage.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 */

/*! \file
 *
 * \brief REALTIME dialplan function
 *
 * \author BJ Weschke <[email protected]>
 *
 * \ingroup functions
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/utils.h"
#include "asterisk/app.h"

/*** DOCUMENTATION
   <function name="REALTIME" language="en_US">
      <synopsis>
         RealTime Read/Write Functions.
      </synopsis>
      <syntax>
         <parameter name="family" required="true" />
         <parameter name="fieldmatch" required="true" />
         <parameter name="matchvalue" />
         <parameter name="delim1|field">
            <para>Use <replaceable>delim1</replaceable> with <replaceable>delim2</replaceable> on
            read and <replaceable>field</replaceable> without <replaceable>delim2</replaceable> on
            write</para>
            <para>If we are reading and <replaceable>delim1</replaceable> is not specified, defaults
            to <literal>,</literal></para>
         </parameter>
         <parameter name="delim2">
            <para>Parameter only used when reading, if not specified defaults to <literal>=</literal></para>
         </parameter>
      </syntax>
      <description>
         <para>This function will read or write values from/to a RealTime repository.
         REALTIME(....) will read names/values from the repository, and
         REALTIME(....)= will write a new value/field to the repository. On a
         read, this function returns a delimited text string. The name/value
         pairs are delimited by <replaceable>delim1</replaceable>, and the name and value are delimited
         between each other with delim2.
         If there is no match, NULL will be returned by the function.
         On a write, this function will always return NULL.</para>
      </description>
      <see-also>
         <ref type="function">REALTIME_STORE</ref>
         <ref type="function">REALTIME_DESTROY</ref>
         <ref type="function">REALTIME_FIELD</ref>
         <ref type="function">REALTIME_HASH</ref>
      </see-also>
   </function>
   <function name="REALTIME_STORE" language="en_US">
      <synopsis>
         RealTime Store Function.
      </synopsis>
      <syntax>
         <parameter name="family" required="true" />
         <parameter name="field1" required="true" />
         <parameter name="fieldN" required="true" multiple="true" />
         <parameter name="field30" required="true" />
      </syntax>
      <description>
         <para>This function will insert a new set of values into the RealTime repository.
         If RT engine provides an unique ID of the stored record, REALTIME_STORE(...)=..
         creates channel variable named RTSTOREID, which contains value of unique ID.
         Currently, a maximum of 30 field/value pairs is supported.</para>
      </description>
      <see-also>
         <ref type="function">REALTIME</ref>
         <ref type="function">REALTIME_DESTROY</ref>
         <ref type="function">REALTIME_FIELD</ref>
         <ref type="function">REALTIME_HASH</ref>
      </see-also>
   </function>
   <function name="REALTIME_DESTROY" language="en_US">
      <synopsis>
         RealTime Destroy Function.
      </synopsis>
      <syntax>
         <parameter name="family" required="true" />
         <parameter name="fieldmatch" required="true" />
         <parameter name="matchvalue" />
         <parameter name="delim1" />
         <parameter name="delim2" />
      </syntax>
      <description>
         <para>This function acts in the same way as REALTIME(....) does, except that
         it destroys the matched record in the RT engine.</para>
         <note>
            <para>If <literal>live_dangerously</literal> in <literal>asterisk.conf</literal>
            is set to <literal>no</literal>, this function can only be read from the
            dialplan, and not directly from external protocols. It can, however, be
            executed as a write operation (<literal>REALTIME_DESTROY(family, fieldmatch)=ignored</literal>)</para>
         </note>
      </description>
      <see-also>
         <ref type="function">REALTIME</ref>
         <ref type="function">REALTIME_STORE</ref>
         <ref type="function">REALTIME_FIELD</ref>
         <ref type="function">REALTIME_HASH</ref>
      </see-also>
   </function>
   <function name="REALTIME_FIELD" language="en_US">
      <synopsis>
         RealTime query function.
      </synopsis>
      <syntax>
         <parameter name="family" required="true" />
         <parameter name="fieldmatch" required="true" />
         <parameter name="matchvalue" required="true" />
         <parameter name="fieldname" required="true" />
      </syntax>
      <description>
         <para>This function retrieves a single item, <replaceable>fieldname</replaceable>
         from the RT engine, where <replaceable>fieldmatch</replaceable> contains the value
         <replaceable>matchvalue</replaceable>.  When written to, the REALTIME_FIELD() function
         performs identically to the REALTIME() function.</para>
      </description>
      <see-also>
         <ref type="function">REALTIME</ref>
         <ref type="function">REALTIME_STORE</ref>
         <ref type="function">REALTIME_DESTROY</ref>
         <ref type="function">REALTIME_HASH</ref>
      </see-also>
   </function>
   <function name="REALTIME_HASH" language="en_US">
      <synopsis>
         RealTime query function.
      </synopsis>
      <syntax>
         <parameter name="family" required="true" />
         <parameter name="fieldmatch" required="true" />
         <parameter name="matchvalue" required="true" />
      </syntax>
      <description>
         <para>This function retrieves a single record from the RT engine, where
         <replaceable>fieldmatch</replaceable> contains the value
         <replaceable>matchvalue</replaceable> and formats the output suitably, such that
         it can be assigned to the HASH() function.  The HASH() function then provides
         a suitable method for retrieving each field value of the record.</para>
      </description>
      <see-also>
         <ref type="function">REALTIME</ref>
         <ref type="function">REALTIME_STORE</ref>
         <ref type="function">REALTIME_DESTROY</ref>
         <ref type="function">REALTIME_FIELD</ref>
      </see-also>
   </function>
 ***/

AST_THREADSTORAGE(buf1);
AST_THREADSTORAGE(buf2);
AST_THREADSTORAGE(buf3);

static int function_realtime_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   struct ast_variable *var, *head;
   struct ast_str *out;
   size_t resultslen;
   int n;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(family);
      AST_APP_ARG(fieldmatch);
      AST_APP_ARG(value);
      AST_APP_ARG(delim1);
      AST_APP_ARG(delim2);
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Syntax: REALTIME(family,fieldmatch[,matchvalue[,delim1[,delim2]]]) - missing argument!\n");
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, data);

   if (!args.delim1)
      args.delim1 = ",";
   if (!args.delim2)
      args.delim2 = "=";

   if (chan)
      ast_autoservice_start(chan);

   head = ast_load_realtime_all(args.family, args.fieldmatch, args.value, SENTINEL);

   if (!head) {
      if (chan)
         ast_autoservice_stop(chan);
      return -1;
   }

   resultslen = 0;
   n = 0;
   for (var = head; var; n++, var = var->next)
      resultslen += strlen(var->name) + strlen(var->value);
   /* add space for delimiters and final '\0' */
   resultslen += n * (strlen(args.delim1) + strlen(args.delim2)) + 1;

   if (resultslen > len) {
      ast_log(LOG_WARNING, "Failed to fetch. Realtime data is too large: need %zu, have %zu.\n", resultslen, len);
      if (chan) {
         ast_autoservice_stop(chan);
      }
      return -1;
   }

   /* len is going to be sensible, so we don't need to check for stack
    * overflows here. */
   out = ast_str_alloca(resultslen);
   for (var = head; var; var = var->next)
      ast_str_append(&out, 0, "%s%s%s%s", var->name, args.delim2, var->value, args.delim1);
   ast_copy_string(buf, ast_str_buffer(out), len);

   ast_variables_destroy(head);

   if (chan)
      ast_autoservice_stop(chan);

   return 0;
}

static int function_realtime_write(struct ast_channel *chan, const char *cmd, char *data, const char *value)
{
   int res = 0;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(family);
      AST_APP_ARG(fieldmatch);
      AST_APP_ARG(value);
      AST_APP_ARG(field);
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Syntax: %s(family,fieldmatch,matchvalue,updatecol) - missing argument!\n", cmd);
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, data);

   if (ast_strlen_zero(args.fieldmatch) || ast_strlen_zero(args.field)) {
      ast_log(LOG_WARNING, "Syntax: %s(family,fieldmatch,matchvalue,updatecol) - missing argument!\n", cmd);
      return -1;
   }

   if (chan) {
      ast_autoservice_start(chan);
   }

   res = ast_update_realtime(args.family, args.fieldmatch, args.value, args.field, (char *)value, SENTINEL);

   if (res < 0) {
      ast_log(LOG_WARNING, "Failed to update. Check the debug log for possible data repository related entries.\n");
   }

   if (chan) {
      ast_autoservice_stop(chan);
   }

   return res;
}

static int realtimefield_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   struct ast_variable *var, *head;
   struct ast_str *escapebuf = ast_str_thread_get(&buf1, 16);
   struct ast_str *fields = ast_str_thread_get(&buf2, 16);
   struct ast_str *values = ast_str_thread_get(&buf3, 16);
   int first = 0;
   enum { rtfield, rthash } which;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(family);
      AST_APP_ARG(fieldmatch);
      AST_APP_ARG(value);
      AST_APP_ARG(fieldname);
   );

   if (!strcmp(cmd, "REALTIME_FIELD")) {
      which = rtfield;
   } else {
      which = rthash;
   }

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Syntax: %s(family,fieldmatch,matchvalue%s) - missing argument!\n", cmd, which == rtfield ? ",fieldname" : "");
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, data);

   if ((which == rtfield && args.argc != 4) || (which == rthash && args.argc != 3)) {
      ast_log(LOG_WARNING, "Syntax: %s(family,fieldmatch,matchvalue%s) - missing argument!\n", cmd, which == rtfield ? ",fieldname" : "");
      return -1;
   }

   if (chan) {
      ast_autoservice_start(chan);
   }

   if (!(head = ast_load_realtime_all(args.family, args.fieldmatch, args.value, SENTINEL))) {
      if (chan) {
         ast_autoservice_stop(chan);
      }
      return -1;
   }

   ast_str_reset(fields);
   ast_str_reset(values);

   for (var = head; var; var = var->next) {
      if (which == rtfield) {
         ast_debug(1, "Comparing %s to %s\n", var->name, args.fieldname);
         if (!strcasecmp(var->name, args.fieldname)) {
            ast_debug(1, "Match! Value is %s\n", var->value);
            ast_copy_string(buf, var->value, len);
            break;
         }
      } else if (which == rthash) {
         ast_debug(1, "Setting hash key %s to value %s\n", var->name, var->value);
         ast_str_append(&fields, 0, "%s%s", first ? "" : ",", ast_str_set_escapecommas(&escapebuf, 0, var->name, INT_MAX));
         ast_str_append(&values, 0, "%s%s", first ? "" : ",", ast_str_set_escapecommas(&escapebuf, 0, var->value, INT_MAX));
         first = 0;
      }
   }
   ast_variables_destroy(head);

   if (which == rthash) {
      pbx_builtin_setvar_helper(chan, "~ODBCFIELDS~", ast_str_buffer(fields));
      ast_copy_string(buf, ast_str_buffer(values), len);
   }

   if (chan) {
      ast_autoservice_stop(chan);
   }

   return 0;
}

static int function_realtime_store(struct ast_channel *chan, const char *cmd, char *data, const char *value)
{
   int res = 0;
   char storeid[32];
   char *valcopy;
   AST_DECLARE_APP_ARGS(a,
      AST_APP_ARG(family);
      AST_APP_ARG(f)[30]; /* fields */
   );

   AST_DECLARE_APP_ARGS(v,
      AST_APP_ARG(v)[30]; /* values */
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Syntax: REALTIME_STORE(family,field1,field2,...,field30) - missing argument!\n");
      return -1;
   }

   if (chan)
      ast_autoservice_start(chan);

   valcopy = ast_strdupa(value);
   AST_STANDARD_APP_ARGS(a, data);
   AST_STANDARD_APP_ARGS(v, valcopy);

   res = ast_store_realtime(a.family,
      a.f[0], v.v[0], a.f[1], v.v[1], a.f[2], v.v[2], a.f[3], v.v[3], a.f[4], v.v[4],
      a.f[5], v.v[5], a.f[6], v.v[6], a.f[7], v.v[7], a.f[8], v.v[8], a.f[9], v.v[9],
      a.f[10], v.v[10], a.f[11], v.v[11], a.f[12], v.v[12], a.f[13], v.v[13], a.f[14], v.v[14],
      a.f[15], v.v[15], a.f[16], v.v[16], a.f[17], v.v[17], a.f[18], v.v[18], a.f[19], v.v[19],
      a.f[20], v.v[20], a.f[21], v.v[21], a.f[22], v.v[22], a.f[23], v.v[23], a.f[24], v.v[24],
      a.f[25], v.v[25], a.f[26], v.v[26], a.f[27], v.v[27], a.f[28], v.v[28], a.f[29], v.v[29], SENTINEL
   );

   if (res < 0) {
      ast_log(LOG_WARNING, "Failed to store. Check the debug log for possible data repository related entries.\n");
   } else {
      snprintf(storeid, sizeof(storeid), "%d", res);
      pbx_builtin_setvar_helper(chan, "RTSTOREID", storeid);
   }

   if (chan)
      ast_autoservice_stop(chan);

   return 0;
}

static int function_realtime_readdestroy(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   struct ast_variable *var, *head;
   struct ast_str *out;
   size_t resultslen;
   int n;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(family);
      AST_APP_ARG(fieldmatch);
      AST_APP_ARG(value);
      AST_APP_ARG(delim1);
      AST_APP_ARG(delim2);
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Syntax: REALTIME_DESTROY(family,fieldmatch[,matchvalue[,delim1[,delim2]]]) - missing argument!\n");
      return -1;
   }

   AST_STANDARD_APP_ARGS(args, data);

   if (!args.delim1)
      args.delim1 = ",";
   if (!args.delim2)
      args.delim2 = "=";

   if (chan)
      ast_autoservice_start(chan);

   head = ast_load_realtime_all(args.family, args.fieldmatch, args.value, SENTINEL);

   if (!head) {
      if (chan)
         ast_autoservice_stop(chan);
      return -1;
   }

   if (len > 0) {
      resultslen = 0;
      n = 0;
      for (var = head; var; n++, var = var->next) {
         resultslen += strlen(var->name) + strlen(var->value);
      }
      /* add space for delimiters and final '\0' */
      resultslen += n * (strlen(args.delim1) + strlen(args.delim2)) + 1;

      if (resultslen > len) {
         /* Unfortunately this does mean that we cannot destroy
          * the row anymore. But OTOH, we're not destroying
          * someones data without giving him the chance to look
          * at it. */
         ast_log(LOG_WARNING, "Failed to fetch/destroy. Realtime data is too large: need %zu, have %zu.\n", resultslen, len);
         if (chan) {
            ast_autoservice_stop(chan);
         }
         return -1;
      }

      /* len is going to be sensible, so we don't need to check for
       * stack overflows here. */
      out = ast_str_alloca(resultslen);
      for (var = head; var; var = var->next) {
         ast_str_append(&out, 0, "%s%s%s%s", var->name, args.delim2, var->value, args.delim1);
      }
      ast_copy_string(buf, ast_str_buffer(out), len);
   }

   ast_destroy_realtime(args.family, args.fieldmatch, args.value, SENTINEL);
   ast_variables_destroy(head);

   if (chan)
      ast_autoservice_stop(chan);

   return 0;
}

/*!
 * \brief Wrapper to execute REALTIME_DESTROY from a write operation. Allows
 * execution even if live_dangerously is disabled.
 */
static int function_realtime_writedestroy(struct ast_channel *chan, const char *cmd, char *data, const char *value)
{
   return function_realtime_readdestroy(chan, cmd, data, NULL, 0);
}

static struct ast_custom_function realtime_function = {
   .name = "REALTIME",
   .read = function_realtime_read,
   .write = function_realtime_write,
};

static struct ast_custom_function realtimefield_function = {
   .name = "REALTIME_FIELD",
   .read = realtimefield_read,
   .write = function_realtime_write,
};

static struct ast_custom_function realtimehash_function = {
   .name = "REALTIME_HASH",
   .read = realtimefield_read,
};

static struct ast_custom_function realtime_store_function = {
   .name = "REALTIME_STORE",
   .write = function_realtime_store,
};

static struct ast_custom_function realtime_destroy_function = {
   .name = "REALTIME_DESTROY",
   .read = function_realtime_readdestroy,
   .write = function_realtime_writedestroy,
};

static int unload_module(void)
{
   int res = 0;
   res |= ast_custom_function_unregister(&realtime_function);
   res |= ast_custom_function_unregister(&realtime_store_function);
   res |= ast_custom_function_unregister(&realtime_destroy_function);
   res |= ast_custom_function_unregister(&realtimefield_function);
   res |= ast_custom_function_unregister(&realtimehash_function);
   return res;
}

static int load_module(void)
{
   int res = 0;
   res |= ast_custom_function_register(&realtime_function);
   res |= ast_custom_function_register(&realtime_store_function);
   res |= ast_custom_function_register_escalating(&realtime_destroy_function, AST_CFE_READ);
   res |= ast_custom_function_register(&realtimefield_function);
   res |= ast_custom_function_register(&realtimehash_function);
   return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Read/Write/Store/Destroy values from a RealTime repository");