[Asterisk-code-review] app_dtmfstore: New application to store digits (asterisk[18])
George Joseph
asteriskteam at digium.com
Tue Aug 3 07:13:11 CDT 2021
George Joseph has submitted this change. ( https://gerrit.asterisk.org/c/asterisk/+/16249 )
Change subject: app_dtmfstore: New application to store digits
......................................................................
app_dtmfstore: New application to store digits
Adds application to asynchronously collect digits
dialed on a channel in the TX or RX direction
using a framehook and stores them in a specified
variable, up to a configurable number of digits.
ASTERISK-29477
Change-Id: I51aa93fc9507f7636ac44806c4420ce690423e6f
---
A apps/app_dtmfstore.c
A doc/CHANGES-staging/app_dtmfstore.txt
2 files changed, 292 insertions(+), 0 deletions(-)
Approvals:
George Joseph: Looks good to me, approved; Approved for Submit
diff --git a/apps/app_dtmfstore.c b/apps/app_dtmfstore.c
new file mode 100644
index 0000000..4e97334
--- /dev/null
+++ b/apps/app_dtmfstore.c
@@ -0,0 +1,286 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2021, Naveen Albert
+ *
+ * Naveen Albert <asterisk at phreaknet.org>
+ *
+ * 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.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Technology independent asynchronous DTMF collection
+ *
+ * \author Naveen Albert <asterisk at phreaknet.org>
+ *
+ * \ingroup functions
+ *
+ */
+
+/*** MODULEINFO
+ <support_level>extended</support_level>
+ ***/
+
+#include "asterisk.h"
+
+#include "asterisk/module.h"
+#include "asterisk/channel.h"
+#include "asterisk/pbx.h"
+#include "asterisk/framehook.h"
+#include "asterisk/app.h"
+#include "asterisk/conversions.h"
+
+/*** DOCUMENTATION
+ <application name="StoreDTMF" language="en_US">
+ <synopsis>
+ Stores DTMF digits transmitted or received on a channel.
+ </synopsis>
+ <syntax>
+ <parameter name="direction" required="true">
+ <para>Must be <literal>TX</literal> or <literal>RX</literal>.</para>
+ </parameter>
+ </syntax>
+ <description>
+ <para>The StoreDTMF function can be used to obtain digits sent in the
+ <literal>TX</literal> or <literal>RX</literal> direction of any channel.</para>
+ <para>The arguments are:</para>
+ <para><replaceable>var_name</replaceable>: Name of variable to which to append
+ digits.</para>
+ <para><replaceable>max_digits</replaceable>: The maximum number of digits to
+ store in the variable. Defaults to 0 (no maximum). After reading <literal>
+ maximum</literal> digits, no more digits will be stored.</para>
+ <para>For example:</para>
+ <para>StoreDTMF(TX,CDR(digits))</para>
+ <para>StoreDTMF(RX,testvar,24)</para>
+ <para>StoreDTMF(remove)</para>
+ </description>
+ </application>
+ ***/
+
+static char *app = "StoreDTMF";
+
+/*! \brief Private data structure used with the function's datastore */
+struct dtmf_store_data {
+ int framehook_id;
+ char *rx_var;
+ char *tx_var;
+ int maxdigits;
+};
+
+static void datastore_destroy_cb(void *data) {
+ struct dtmf_store_data *d;
+ d = data;
+ if (d) {
+ if (d->rx_var) {
+ ast_free(d->rx_var);
+ }
+ if (d->tx_var) {
+ ast_free(d->tx_var);
+ }
+ ast_free(data);
+ }
+}
+
+/*! \brief The channel datastore the function uses to store state */
+static const struct ast_datastore_info dtmf_store_datastore = {
+ .type = "dtmf_store",
+ .destroy = datastore_destroy_cb
+};
+
+/*! \internal \brief Store digits tx/rx on the channel */
+static int remove_dtmf_store(struct ast_channel *chan)
+{
+ struct ast_datastore *datastore = NULL;
+ struct dtmf_store_data *data;
+ SCOPED_CHANNELLOCK(chan_lock, chan);
+
+ datastore = ast_channel_datastore_find(chan, &dtmf_store_datastore, NULL);
+ if (!datastore) {
+ ast_log(AST_LOG_WARNING, "Cannot remove StoreDTMF from %s: StoreDTMF not currently enabled\n",
+ ast_channel_name(chan));
+ return -1;
+ }
+ data = datastore->data;
+
+ if (ast_framehook_detach(chan, data->framehook_id)) {
+ ast_log(AST_LOG_WARNING, "Failed to remove StoreDTMF framehook from channel %s\n",
+ ast_channel_name(chan));
+ return -1;
+ }
+
+ if (ast_channel_datastore_remove(chan, datastore)) {
+ ast_log(AST_LOG_WARNING, "Failed to remove StoreDTMF datastore from channel %s\n",
+ ast_channel_name(chan));
+ return -1;
+ }
+ ast_datastore_free(datastore);
+
+ return 0;
+}
+
+/*! \brief Frame hook that is called to intercept digit/undigit */
+static struct ast_frame *dtmf_store_framehook(struct ast_channel *chan,
+ struct ast_frame *f, enum ast_framehook_event event, void *data)
+{
+ char currentdata[512];
+ char varnamesub[64];
+ char *varname = NULL;
+ struct dtmf_store_data *framedata = data;
+ int len;
+
+ if (!f || !framedata) {
+ return f;
+ }
+
+ if ((event != AST_FRAMEHOOK_EVENT_WRITE) && (event != AST_FRAMEHOOK_EVENT_READ)) {
+ return f;
+ }
+
+ if (f->frametype != AST_FRAME_DTMF_END) {
+ return f;
+ }
+
+ /* If this is DTMF then store the digits */
+ if (event == AST_FRAMEHOOK_EVENT_READ && framedata->rx_var) { /* coming from source */
+ varname = framedata->rx_var;
+ } else if (event == AST_FRAMEHOOK_EVENT_WRITE && framedata->tx_var) { /* going to source */
+ varname = framedata->tx_var;
+ }
+
+ if (!varname) {
+ return f;
+ }
+
+ sprintf(varnamesub, "${%s}", varname);
+ pbx_substitute_variables_helper(chan, varnamesub, currentdata, 511);
+ /* pbx_builtin_getvar_helper works for regular vars but not CDR vars */
+ if (ast_strlen_zero(currentdata)) { /* var doesn't exist yet */
+ ast_debug(3, "Creating new digit store: %s\n", varname);
+ }
+ len = strlen(currentdata);
+ if (framedata->maxdigits > 0 && len >= framedata->maxdigits) {
+ ast_debug(3, "Reached digit limit: %d\n", framedata->maxdigits);
+ remove_dtmf_store(chan); /* reached max digit count, stop now */
+ return f;
+ } else {
+ char newdata[len + 2]; /* one more char + terminator */
+ if (len > 0) {
+ ast_copy_string(newdata, currentdata, len + 2);
+ }
+ newdata[len] = (unsigned) f->subclass.integer;
+ newdata[len + 1] = '\0';
+ ast_debug(3, "Appending to digit store: now %s\n", newdata);
+ pbx_builtin_setvar_helper(chan, varname, newdata);
+ }
+ return f;
+}
+
+/*! \internal \brief Enable digit interception on the channel */
+static int dtmfstore_exec(struct ast_channel *chan, const char *appdata)
+{
+ struct ast_datastore *datastore;
+ struct dtmf_store_data *data;
+ static struct ast_framehook_interface digit_framehook_interface = {
+ .version = AST_FRAMEHOOK_INTERFACE_VERSION,
+ .event_cb = dtmf_store_framehook,
+ .disable_inheritance = 1,
+ };
+ char *parse = ast_strdupa(appdata);
+ AST_DECLARE_APP_ARGS(args,
+ AST_APP_ARG(direction);
+ AST_APP_ARG(varname);
+ AST_APP_ARG(maxdigits);
+ );
+ SCOPED_CHANNELLOCK(chan_lock, chan);
+ AST_STANDARD_APP_ARGS(args, parse);
+
+ if (ast_strlen_zero(appdata)) {
+ ast_log(AST_LOG_WARNING, "StoreDTMF requires an argument\n");
+ return -1;
+ }
+
+ if (!strcasecmp(args.direction, "remove")) {
+ return remove_dtmf_store(chan);
+ }
+
+ datastore = ast_channel_datastore_find(chan, &dtmf_store_datastore, NULL);
+ if (datastore) {
+ ast_log(AST_LOG_WARNING, "StoreDTMF already set on '%s'\n",
+ ast_channel_name(chan));
+ return 0;
+ }
+
+ datastore = ast_datastore_alloc(&dtmf_store_datastore, NULL);
+ if (!datastore) {
+ return -1;
+ }
+
+ data = ast_calloc(1, sizeof(*data));
+ if (!data) {
+ ast_datastore_free(datastore);
+ return -1;
+ }
+
+ digit_framehook_interface.data = data;
+
+ data->rx_var = NULL;
+ data->tx_var = NULL;
+ data->maxdigits = 0;
+
+ if (!strcasecmp(args.direction, "tx")) {
+ data->tx_var = ast_strdup(args.varname);
+ } else if (!strcasecmp(args.direction, "rx")) {
+ data->rx_var = ast_strdup(args.varname);
+ } else {
+ ast_log(LOG_ERROR, "Direction must be either RX or TX\n");
+ return -1;
+ }
+
+ if (!ast_strlen_zero(args.maxdigits)) {
+ if (ast_str_to_int(args.maxdigits,&(data->maxdigits))) {
+ ast_log(LOG_ERROR, "Invalid integer: %s\n", args.maxdigits);
+ return -1;
+ }
+ if (data->maxdigits < 0) {
+ ast_log(LOG_ERROR, "Invalid natural number: %d\n", data->maxdigits);
+ return -1;
+ } else if (data->maxdigits == 0) {
+ ast_log(LOG_WARNING, "No maximum digit count set\n");
+ }
+ }
+
+ data->framehook_id = ast_framehook_attach(chan, &digit_framehook_interface);
+ if (data->framehook_id < 0) {
+ ast_log(AST_LOG_WARNING, "Failed to attach StoreDTMF framehook to '%s'\n",
+ ast_channel_name(chan));
+ ast_datastore_free(datastore);
+ ast_free(data);
+ return -1;
+ }
+ datastore->data = data;
+
+ ast_channel_datastore_add(chan, datastore);
+
+ return 0;
+}
+
+static int unload_module(void)
+{
+ return ast_unregister_application(app);
+}
+
+static int load_module(void)
+{
+ return ast_register_application_xml(app, dtmfstore_exec);
+}
+
+AST_MODULE_INFO_STANDARD_EXTENDED(ASTERISK_GPL_KEY, "Technology independent async DTMF storage");
diff --git a/doc/CHANGES-staging/app_dtmfstore.txt b/doc/CHANGES-staging/app_dtmfstore.txt
new file mode 100644
index 0000000..a82b543
--- /dev/null
+++ b/doc/CHANGES-staging/app_dtmfstore.txt
@@ -0,0 +1,6 @@
+Subject: app_dtmfstore
+
+New application which collects digits
+dialed and stores them into
+a specified variable.
+
--
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Gerrit-Project: asterisk
Gerrit-Branch: 18
Gerrit-Change-Id: I51aa93fc9507f7636ac44806c4420ce690423e6f
Gerrit-Change-Number: 16249
Gerrit-PatchSet: 1
Gerrit-Owner: N A <mail at interlinked.x10host.com>
Gerrit-Reviewer: Friendly Automation
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-MessageType: merged
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