Provide the ability to adjust txgain/rxgain on a channel level via the CHANNEL() function

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@24621 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_zap.c

@@ -698,6 +698,7 @@ struct ast_frame *zt_exception(struct ast_channel *ast);
 static int zt_indicate(struct ast_channel *chan, int condition);
 static int zt_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
 static int zt_setoption(struct ast_channel *chan, int option, void *data, int datalen);
+static int zt_func_read(struct ast_channel *chan, char *function, char *data, char *buf, size_t len); 
 
 static const struct ast_channel_tech zap_tech = {
 	.type = "Zap",
@@ -716,6 +717,7 @@ static const struct ast_channel_tech zap_tech = {
 	.indicate = zt_indicate,
 	.fixup = zt_fixup,
 	.setoption = zt_setoption,
+	.func_channel_read = zt_func_read,
 };
 
 #ifdef HAVE_LIBPRI
@@ -2904,6 +2906,25 @@ static int zt_setoption(struct ast_channel *chan, int option, void *data, int da
 	return 0;
 }
 
+static int zt_func_read(struct ast_channel *chan, char *function, char *data, char *buf, size_t len)
+{
+	struct zt_pvt *p = chan->tech_pvt;
+	
+	if (!strcasecmp(data, "rxgain")) {
+		ast_mutex_lock(&p->lock);
+		snprintf(buf, len, "%f", p->rxgain);
+		ast_mutex_unlock(&p->lock);	
+	} else if (!strcasecmp(data, "txgain")) {
+		ast_mutex_lock(&p->lock);
+		snprintf(buf, len, "%f", p->txgain);
+		ast_mutex_unlock(&p->lock);	
+	} else {
+		ast_copy_string(buf, "", len);
+	}
+	return 0;
+}
+
+
 static void zt_unlink(struct zt_pvt *slave, struct zt_pvt *master, int needlock)
 {
 	/* Unlink a specific slave or all slaves/masters from a given master */

funcs/func_channel.c

@@ -23,6 +23,7 @@
  */
 
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <sys/types.h>
 
@@ -93,6 +94,7 @@ static int func_channel_write(struct ast_channel *chan, char *function,
 			      char *data, const char *value)
 {
 	int ret = 0;
+	signed char gainset;
 
 	if (!strcasecmp(data, "language"))
 		locked_string_field_set(chan, language, value);
@@ -100,7 +102,13 @@ static int func_channel_write(struct ast_channel *chan, char *function,
 		locked_string_field_set(chan, musicclass, value);
 	else if (!strcasecmp(data, "callgroup"))
 		chan->callgroup = ast_get_group(data);
-	else if (!chan->tech->func_channel_write
+	else if (!strcasecmp(data, "txgain")) {
+		sscanf(value, "%hhd", &gainset);
+		ast_channel_setoption(chan, AST_OPTION_TXGAIN, &gainset, sizeof(gainset), 0);
+	} else if (!strcasecmp(data, "rxgain")) {
+		sscanf(value, "%hhd", &gainset);
+		ast_channel_setoption(chan, AST_OPTION_RXGAIN, &gainset, sizeof(gainset), 0);	
+	} else if (!chan->tech->func_channel_write
 		 || chan->tech->func_channel_write(chan, function, data, value)) {
 		ast_log(LOG_WARNING, "Unknown or unavailable item requested: '%s'\n",
 				data);
@@ -123,8 +131,10 @@ static struct ast_custom_function channel_function = {
 		"R/O	channeltype		technology used for channel\n"
 		"R/W	language 		language for sounds played\n"
 		"R/W	musicclass 		class (from musiconhold.conf) for hold music\n"
+		"R/W	rxgain			set rxgain level on channel drivers that support it\n"
 		"R/O	state			state for channel\n"
 		"R/O	tonezone 		zone for indications played\n"
+		"R/W	txgain			set txgain level on channel drivers that support it\n"
 		"R/O	videonativeformat 	format used natively for video\n"
 		"\n"
 		"Additional items may be available from the channel driver providing\n"