From a6bb331e18b6583e2140209dda9b5beec55a97ba Mon Sep 17 00:00:00 2001
From: Richard Mudgett <rmudgett@digium.com>
Date: Mon, 14 Mar 2011 16:50:59 +0000
Subject: [PATCH] Merged revisions 310635 via svnmerge from
 https://origsvn.digium.com/svn/asterisk/branches/1.6.2

................
  r310635 | rmudgett | 2011-03-14 11:47:54 -0500 (Mon, 14 Mar 2011) | 32 lines

  Merged revisions 310633 via svnmerge from
  https://origsvn.digium.com/svn/asterisk/branches/1.4

  ........
    r310633 | rmudgett | 2011-03-14 11:38:24 -0500 (Mon, 14 Mar 2011) | 25 lines

    "Caller*ID failed checksum" on Wildcard TDM2400P and TDM410

    The last character in the caller id message is getting a framing error.

    The checksum is the last character in the message.  A framing error in the
    checksum could be because:
    1) The sender did not send a full stop bit.
    2) The sender cut off the FSK carrier too soon.
    3) The sender opted to send zero of the specified zero to 10 trailing mark
    bits and round-off errors in the code resulted in the code not being where
    it thought it was in the demodulated bit stream.

    Bit 8 of 'b' is set when parity error.
    Bit 9 of 'b' is set when framing error.

    Made ignore the framing and parity error bits if the errored character is
    the checksum.  We can tolerate a framing/parity error there.  The checksum
    character validates the message.

    (closes issue #18474)
    Reported by: nivek
    Patches:
          callerid.c.1.patch uploaded by nivek (license 636) (with modifications)
    Tested by: nivek
  ........
................


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@310636 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---
 main/callerid.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/main/callerid.c b/main/callerid.c
index ac8fbde8b1..3af85b467b 100644
--- a/main/callerid.c
+++ b/main/callerid.c
@@ -568,9 +568,22 @@ int callerid_feed(struct callerid_state *cid, unsigned char *ubuf, int len, form
 			return -1;
 		}
 		if (res == 1) {
-			/* Ignore invalid bytes */
-			if (b > 0xff)
-				continue;
+			if (b > 0xff) {
+				if (cid->sawflag != 5) {
+					/* Ignore invalid bytes */
+					continue;
+				}
+				/*
+				 * We can tollerate an error on the checksum character since the
+				 * checksum character is the last character in the message and
+				 * it validates the message.
+				 *
+				 * Remove character error flags.
+				 * Bit 8 : Parity error
+				 * Bit 9 : Framing error
+				 */
+				b &= 0xff;
+			}
 			switch (cid->sawflag) {
 			case 0: /* Look for flag */
 				if (b == 'U')