Rewrite Packet Uplink Assignment

Use bitvec_set_*() directly without external write pointer tracking to
simplify the code. This is part of IA Rest Octets (3GPP TS 44.018
§10.5.2.16) which is the last part of the message so it should not
interfere with the rest of encoding functions.

The tests are adjusted accordingly.

Change-Id: I44db2eeea7448ff67e688ae716487bc6dbfc96a3
Related: OS#1526

1 files changed, 48 insertions, 48 deletions

diff --git a/src/encoding.cpp b/src/encoding.cpp
index 279bbfe8..e96894f2 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -230,50 +230,51 @@ static inline int write_ia_rest_downlink(const gprs_rlcmac_dl_tbf *tbf, bitvec *
 	return 0;
 }
 
-static int write_ia_rest_uplink(
-	gprs_rlcmac_ul_tbf *tbf,
-	bitvec * dest, unsigned& wp,
-	uint8_t usf, uint32_t fn,
-	uint8_t alpha, uint8_t gamma, int8_t ta_idx)
+/* 3GPP TS 44.018 §10.5.2.16 IA Rest Octets ::= Packet Uplink Assignment */
+static inline int write_ia_rest_uplink(const gprs_rlcmac_ul_tbf *tbf, bitvec * dest,
+				       uint8_t usf, uint32_t fn, uint8_t alpha, uint8_t gamma, int8_t ta_idx)
 {
-	OSMO_ASSERT(!tbf || !tbf->is_egprs_enabled());
-
-	// GMS 04.08 10.5.2.37b 10.5.2.16
-	bitvec_write_field(dest, &wp, 3, 2);    // "HH"
-	bitvec_write_field(dest, &wp, 0, 2);    // "0" Packet Uplink Assignment
-	if (tbf == NULL) {
-		bitvec_write_field(dest, &wp, 0, 1);    // Block Allocation : Single Block Allocation
-		if (alpha) {
-			bitvec_write_field(dest, &wp,0x1,1);   // ALPHA = present
-			bitvec_write_field(dest, &wp,alpha,4);   // ALPHA = present
-		} else
-			bitvec_write_field(dest, &wp,0x0,1);   // ALPHA = not present
-		bitvec_write_field(dest, &wp,gamma,5);   // GAMMA power control parameter
-		write_tai(dest, wp, ta_idx);
-		bitvec_write_field(dest, &wp, 1, 1);    // TBF_STARTING_TIME_FLAG
-		bitvec_write_field(dest, &wp,(fn / (26 * 51)) % 32,5); // T1'
-		bitvec_write_field(dest, &wp,fn % 51,6);               // T3
-		bitvec_write_field(dest, &wp,fn % 26,5);               // T2
+	int rc;
+
+	set_H(dest); set_H(dest);
+	set_0(dest); set_0(dest); /* 00 Packet Uplink Assignment */
+
+	if (tbf) {
+		set_1(dest); /* Multi Block Allocation */
+
+		rc = write_tfi_usf(dest, tbf, usf);
+		check(rc);
+
+		/* 3GPP TS 44.060 Table 11.2.28.2 Channel Coding Indicator */
+		rc = bitvec_set_u64(dest, tbf->current_cs().to_num() - 1, 2, false); /* CHANNEL_CODING_COMMAND */
+		check(rc);
+
+		rc = bitvec_set_bit(dest, (bit_value)tbf->tlli());                   /* TLLI_BLOCK_CHANNEL_CODING */
+		check(rc);
+
+		rc = write_alpha_gamma(dest, alpha, gamma);
+		check(rc);
+
+		set_0(dest); /* No TIMING_ADVANCE_INDEX */
+		set_0(dest); /* No TBF_STARTING_TIME */
 	} else {
-		bitvec_write_field(dest, &wp, 1, 1);    // Block Allocation : Not Single Block Allocation
-		bitvec_write_field(dest, &wp, tbf->tfi(), 5);  // TFI_ASSIGNMENT Temporary Flow Identity
-		bitvec_write_field(dest, &wp, 0, 1);    // POLLING
-		bitvec_write_field(dest, &wp, 0, 1);    // ALLOCATION_TYPE: dynamic
-		bitvec_write_field(dest, &wp, usf, 3);    // USF
-		bitvec_write_field(dest, &wp, 0, 1);    // USF_GRANULARITY
-		bitvec_write_field(dest, &wp, 0, 1);   // "0" power control: Not Present
-		bitvec_write_field(dest, &wp, tbf->current_cs().to_num()-1, 2);    // CHANNEL_CODING_COMMAND
-		bitvec_write_field(dest, &wp, 1, 1);    // TLLI_BLOCK_CHANNEL_CODING
-		if (alpha) {
-			bitvec_write_field(dest, &wp,0x1,1);   // ALPHA = present
-			bitvec_write_field(dest, &wp,alpha,4);   // ALPHA
-		} else
-			bitvec_write_field(dest, &wp,0x0,1);   // ALPHA = not present
-		bitvec_write_field(dest, &wp,gamma,5);   // GAMMA power control parameter
-		/* note: there is no choise for TAI and no starting time */
-		bitvec_write_field(dest, &wp, 0, 1);   // switch TIMING_ADVANCE_INDEX = off
-		bitvec_write_field(dest, &wp, 0, 1);    // TBF_STARTING_TIME_FLAG
+		set_0(dest); /* Single Block Allocation */
+		rc = write_alpha_gamma(dest, alpha, gamma);
+		check(rc);
+
+		/* A 'Timing Advance index' shall not be allocated at a Single Block allocation.
+		   A 'TBF Starting Time' shall be allocated at a Single Block allocation. */
+		set_0(dest);
+		set_1(dest);
+
+		rc = write_tbf_start_time(dest, fn);	/* TBF_STARTING_TIME */
+		check(rc);
+
+		set_L(dest); /* No P0 nor PR_MODE */
+		set_L(dest); /* No Additions for R99 */
+		set_L(dest); /* No Additions for Rel-6 */
 	}
+
 	return 0;
 }
 
@@ -481,22 +482,21 @@ int Encoding::write_immediate_assignment(
 
 	plen = wp / 8;
 
+	dest->cur_bit = wp;
 	if (downlink) {
 		if (!as_dl_tbf(tbf)) {
 			LOGP(DRLCMACDL, LOGL_ERROR, "Cannot encode DL IMMEDIATE ASSIGNMENT without TBF\n");
 			return -EINVAL;
 		}
-		dest->cur_bit = wp;
 		rc = write_ia_rest_downlink(as_dl_tbf(tbf), dest, polling, gsm48_ta_is_valid(ta), fn,
 					    alpha, gamma, ta_idx);
 	} else if (((burst_type == GSM_L1_BURST_TYPE_ACCESS_1) ||
-		  (burst_type == GSM_L1_BURST_TYPE_ACCESS_2))) {
-		dest->cur_bit = wp;
+		    (burst_type == GSM_L1_BURST_TYPE_ACCESS_2)))
 		rc = write_ia_rest_egprs_uplink(as_ul_tbf(tbf), dest, usf, fn, alpha, gamma, ta_idx, burst_type, ra);
-	} else
-		rc = write_ia_rest_uplink(as_ul_tbf(tbf), dest, wp,
-			usf, fn,
-			alpha, gamma, ta_idx);
+	else {
+		OSMO_ASSERT(!as_ul_tbf(tbf) || !as_ul_tbf(tbf)->is_egprs_enabled());
+		rc = write_ia_rest_uplink(as_ul_tbf(tbf), dest, usf, fn, alpha, gamma, ta_idx);
+	}
 
 	if (rc < 0) {
 		LOGP(DRLCMAC, LOGL_ERROR,