rlc: Start to move things out of the tbf into the rlc

Add remarks of possible broken behavior inside the tbf
routines. Move the preparation (and init) into the new
rlc.cpp file.

4 files changed, 50 insertions, 11 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index daa91ec6..beee4c09 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -48,7 +48,8 @@ libgprs_la_SOURCES = \
 	ta.cpp \
 	sba.cpp \
 	decoding.cpp \
-	llc.cpp
+	llc.cpp \
+	rlc.cpp
 
 if ENABLE_SYSMOBTS
 libgprs_la_SOURCES += \
diff --git a/src/rlc.cpp b/src/rlc.cpp
new file mode 100644
index 00000000..4319c499
--- /dev/null
+++ b/src/rlc.cpp
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2013 by Holger Hans Peter Freyther
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#include "tbf.h"
+
+extern "C" {
+#include <osmocom/core/utils.h>
+}
+
+
+uint8_t *gprs_rlc_data::prepare(size_t block_data_len)
+{
+	/* todo.. only set it once if it turns out to be a bottleneck */
+	memset(block, 0x0, ARRAY_SIZE(block));
+	memset(block, 0x2b, block_data_len);
+
+	return block;
+}
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 3fd24815..0226691f 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -878,8 +878,6 @@ struct msgb *gprs_rlcmac_tbf::create_dl_acked_block(uint32_t fn, uint8_t ts)
 {
 	struct rlc_dl_header *rh;
 	struct rlc_li_field *li;
-	uint8_t block_length; /* total length of block, including spare bits */
-	uint8_t block_data; /* usable data of block, w/o spare bits, inc. MAC */
 	struct msgb *msg;
 	uint8_t bsn;
 	uint16_t mod_sns = sns - 1;
@@ -966,18 +964,21 @@ do_resend:
 	LOGP(DRLCMACDL, LOGL_DEBUG, "- Sending new block at BSN %d\n",
 		dir.dl.v_s);
 
-	/* now we still have untransmitted LLC data, so we fill mac block */
-	index = dir.dl.v_s & mod_sns_half;
-	data = m_rlc.blocks[index].block;
 #warning "Selection of the CS doesn't belong here"
 	if (cs == 0) {
 		cs = bts_data()->initial_cs_dl;
 		if (cs < 1 || cs > 4)
 			cs = 1;
 	}
-	block_length = gprs_rlcmac_cs[cs].block_length;
-	block_data = gprs_rlcmac_cs[cs].block_data;
-	memset(data, 0x2b, block_data); /* spare bits will be left 0 */
+	/* total length of block, including spare bits */
+	const uint8_t block_length = gprs_rlcmac_cs[cs].block_length;
+	/* length of usable data of block, w/o spare bits, inc. MAC */
+	const uint8_t block_data_len = gprs_rlcmac_cs[cs].block_data;
+
+	/* now we still have untransmitted LLC data, so we fill mac block */
+	index = dir.dl.v_s & mod_sns_half;
+	data = m_rlc.blocks[index].prepare(block_data_len);
+
 	rh = (struct rlc_dl_header *)data;
 	rh->pt = 0; /* Data Block */
 	rh->rrbp = rh->s_p = 0; /* Polling, set later, if required */
@@ -988,9 +989,9 @@ do_resend:
 	rh->bsn = dir.dl.v_s; /* Block Sequence Number */
 	rh->e = 0; /* Extension bit, maybe set later */
 	e_pointer = data + 2; /* points to E of current chunk */
-	data += 3;
+	data += sizeof(*rh);
 	delimiter = data; /* where next length header would be stored */
-	space = block_data - 3;
+	space = block_data_len - sizeof(*rh);
 	while (1) {
 		chunk = m_llc.chunk_size();
 		/* if chunk will exceed block limit */
@@ -1107,6 +1108,7 @@ do_resend:
 	}
 	LOGP(DRLCMACDL, LOGL_DEBUG, "data block: %s\n",
 		osmo_hexdump(m_rlc.blocks[index].block, block_length));
+#warning "move this up?"
 	m_rlc.blocks[index].len = block_length;
 	/* raise send state and set ack state array */
 	dir.dl.v_b[index] = 'U'; /* unacked */
@@ -1152,6 +1154,7 @@ struct msgb *gprs_rlcmac_tbf::create_dl_acked_block(
 			LOGP(DRLCMAC, LOGL_DEBUG, "Polling cannot be "
 				"sheduled in this TS %d, waiting for "
 				"TS %d\n", ts, control_ts);
+#warning "What happens to the first_fin_ack in case something is already scheduled?"
 		else if (bts->sba()->find(trx->trx_no, ts, (fn + 13) % 2715648))
 			LOGP(DRLCMAC, LOGL_DEBUG, "Polling cannot be "
 				"sheduled, because single block alllocation "
diff --git a/src/tbf.h b/src/tbf.h
index bf5f32d6..e95ed204 100644
--- a/src/tbf.h
+++ b/src/tbf.h
@@ -86,6 +86,8 @@ enum gprs_rlcmac_tbf_direction {
 #define GPRS_RLCMAC_FLAG_TO_MASK	0xf0 /* timeout bits */
 
 struct gprs_rlc_data {
+	uint8_t *prepare(size_t block_data_length);
+
 	/* block history */
 	uint8_t block[RLC_MAX_LEN];
 	/* block len  of history */