[Asterisk-code-review] res rtp asterisk: Avoid merging command and regular T.140 te... (asterisk[13])

[Joshua Colp]

Joshua Colp has submitted this change and it was merged. ( https://gerrit.asterisk.org/9510 )

Change subject: res_rtp_asterisk: Avoid merging command and regular T.140 text packets
......................................................................

res_rtp_asterisk: Avoid merging command and regular T.140 text packets

When realtime text packets are to be sent, the text is accumulated in a
buffer and sent regularly by a timer.  It can happen that commands such as
a backspace, CR, or LF get merged with regular text.  This breaks some
UAs.

The proposed change:
* We test if the current packet contains a command.  If so we send the
buffer immediately.
* We test if the buffer contained a command.  If so we send the buffer
immediately.
* We accumulate the text (or the command) in the buffer.

ASTERISK-27970

Change-Id: Ifbe993311410fa855cb8aa4a12084db75f413462
---
M res/res_rtp_asterisk.c
1 file changed, 22 insertions(+), 2 deletions(-)

Approvals:
  Richard Mudgett: Looks good to me, but someone else must approve
  Kevin Harwell: Looks good to me, but someone else must approve
  Joshua Colp: Looks good to me, approved; Approved for Submit



diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index 1a1307f..d101fcb 100644
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -6101,9 +6101,29 @@
 static int rtp_red_buffer(struct ast_rtp_instance *instance, struct ast_frame *frame)
 {
 	struct ast_rtp *rtp = ast_rtp_instance_get_data(instance);
+	struct rtp_red *red = rtp->red;
 
-	if (frame->datalen > -1) {
-		struct rtp_red *red = rtp->red;
+	if (!red) {
+		return 0;
+	}
+
+	if (frame->datalen > 0) {
+		if (red->t140.datalen > 0) {
+			const unsigned char *primary = red->buf_data;
+
+			/* There is something already in the T.140 buffer */
+			if (primary[0] == 0x08 || primary[0] == 0x0a || primary[0] == 0x0d) {
+				/* Flush the previous T.140 packet if it is a command */
+				ast_rtp_write(instance, &rtp->red->t140);
+			} else {
+				primary = frame->data.ptr;
+				if (primary[0] == 0x08 || primary[0] == 0x0a || primary[0] == 0x0d) {
+					/* Flush the previous T.140 packet if we are buffering a command now */
+					ast_rtp_write(instance, &rtp->red->t140);
+				}
+			}
+		}
+
 		memcpy(&red->buf_data[red->t140.datalen], frame->data.ptr, frame->datalen);
 		red->t140.datalen += frame->datalen;
 		red->t140.ts = frame->ts;

-- 
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Gerrit-Project: asterisk
Gerrit-Branch: 13
Gerrit-MessageType: merged
Gerrit-Change-Id: Ifbe993311410fa855cb8aa4a12084db75f413462
Gerrit-Change-Number: 9510
Gerrit-PatchSet: 6
Gerrit-Owner: Emmanuel BUU <emmanuel.buu at ives.fr>
Gerrit-Reviewer: Jenkins2
Gerrit-Reviewer: Joshua Colp <jcolp at digium.com>
Gerrit-Reviewer: Kevin Harwell <kharwell at digium.com>
Gerrit-Reviewer: Richard Mudgett <rmudgett at digium.com>
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