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authorPau Espin Pedrol <pespin@sysmocom.de>2020-04-30 20:22:38 +0200
committerPau Espin Pedrol <pespin@sysmocom.de>2020-05-01 15:54:17 +0200
commit2456dad91e22b1cb9997890b4a7b6a6399c26ab7 (patch)
tree58d8bd58ace402bf7b63c6f34f17e3c92238673d /library
parent27d6af5edbac8a165eb497515dc35b63be441578 (diff)
RLCMAC_EncDec.cc: Fix egprs data block encode alignment
Selftests I'm using in the pcu testsuite to verify encoding are attached too. Change-Id: Id0e21248853eb5fac89e863822804cfbecf3c865
Diffstat (limited to 'library')
-rw-r--r--library/RLCMAC_EncDec.cc135
-rw-r--r--library/RLCMAC_Templates.ttcn32
2 files changed, 156 insertions, 11 deletions
diff --git a/library/RLCMAC_EncDec.cc b/library/RLCMAC_EncDec.cc
index 8f3ff2f..d25a7e0 100644
--- a/library/RLCMAC_EncDec.cc
+++ b/library/RLCMAC_EncDec.cc
@@ -2,6 +2,7 @@
#include <endian.h>
#include "RLCMAC_Types.hh"
+#include "RLCMAC_Templates.hh"
#include "GSM_Types.hh"
/* Decoding of TS 44.060 GPRS RLC/MAC blocks, portions requiring manual functions
* beyond what TITAN RAW coder can handle internally.
@@ -172,6 +173,22 @@ struct gprs_rlc_dl_header_egprs_3 {
#endif
} __attribute__ ((packed));
+/*
+static const char hex_chars[] = "0123456789abcdef";
+void printbuffer(const char* ptr, TTCN_Buffer& buf) {
+ int len = buf.get_len();
+ const unsigned char* cbuf = buf.get_data();
+
+ fprintf(stderr, "printbuffer %s (len=%d): [", ptr, len);
+
+ for (int i = 0; i < len; i++) {
+ fprintf(stderr, " %c%c", hex_chars[cbuf[i] >> 4], hex_chars[cbuf[i] & 0xf]);
+ }
+
+ fprintf(stderr, " ]\n");
+}
+*/
+
static CodingScheme::enum_type payload_len_2_coding_scheme(size_t payload_len) {
switch (payload_len) {
case 23:
@@ -294,7 +311,7 @@ static void clone_aligned_buffer_lsbf(unsigned int offset_bits, unsigned int len
hdr_bytes = offset_bits / 8;
extra_bits = offset_bits % 8;
- fprintf(stderr, "RLMAC: clone: hdr_bytes=%u extra_bits=%u (length_bytes=%u)\n", hdr_bytes, extra_bits, length_bytes);
+ //fprintf(stderr, "RLMAC: clone: hdr_bytes=%u extra_bits=%u (length_bytes=%u)\n", hdr_bytes, extra_bits, length_bytes);
if (extra_bits == 0) {
/* It is aligned already */
@@ -324,9 +341,8 @@ static void get_egprs_data_block(const TTCN_Buffer& orig_ttcn_buffer, unsigned i
size_t length_bytes = (initial_spare_bits + length_bits + 7) / 8;
size_t accepted_len = length_bytes;
- fprintf(stderr, "RLMAC: trying to allocate %u bytes (orig is %zu bytes long with read pos %zu)\n", length_bytes, orig_ttcn_buffer.get_len(), orig_ttcn_buffer.get_pos());
+ //fprintf(stderr, "RLMAC: trying to allocate %u bytes (orig is %zu bytes long with read pos %zu)\n", length_bytes, orig_ttcn_buffer.get_len(), orig_ttcn_buffer.get_pos());
dst_ttcn_buffer.get_end(aligned_buf, accepted_len);
- fprintf(stderr, "RLMAC: For dst ptr=%p with length=%zu\n", aligned_buf, accepted_len);
if (accepted_len < length_bytes) {
fprintf(stderr, "RLMAC: ERROR! asked for %zu bytes but got %zu\n", length_bytes, accepted_len);
}
@@ -337,14 +353,90 @@ static void get_egprs_data_block(const TTCN_Buffer& orig_ttcn_buffer, unsigned i
orig_ttcn_buffer.get_data(),
aligned_buf);
- fprintf(stderr, "RLMAC: clone_aligned_buffer_lsbf success\n");
-
/* clear spare bits and move block header bits to the right */
aligned_buf[0] = aligned_buf[0] >> initial_spare_bits;
dst_ttcn_buffer.increase_length(length_bytes);
}
+/* bit-shift the entire 'src' of length 'length_bytes'
+ * and store the result to caller-allocated 'buffer' by 'offset_bits'. The shifting is
+ * done lsb-first. */
+static void clone_unaligned_buffer_lsbf(unsigned int offset_bits, unsigned int length_bytes,
+ const uint8_t *src, uint8_t *buffer)
+{
+ unsigned int hdr_bytes;
+ unsigned int extra_bits;
+ unsigned int i;
+
+ uint8_t c, last_hdr_c, last_c;
+ uint8_t *dst;
+
+ hdr_bytes = offset_bits / 8;
+ extra_bits = offset_bits % 8;
+
+ //fprintf(stderr, "RLMAC: clone: hdr_bytes=%u extra_bits=%u (length_bytes=%u)\n", hdr_bytes, extra_bits, length_bytes);
+
+ if (extra_bits == 0) {
+ /* It is aligned already */
+ memcpy(buffer, src + hdr_bytes, length_bytes);
+ return;
+ }
+
+ /* Copy first header+data byte, it's not handled correctly by loop */
+ dst = buffer + hdr_bytes;
+ last_hdr_c = *dst;
+ last_c = *dst << (8 - extra_bits);
+
+ for (i = 0; i < length_bytes; i++) {
+ c = src[i];
+ *(dst++) = (last_c >> (8 - extra_bits)) | (c << extra_bits);
+ last_c = c;
+ }
+ /* overwrite the lower extra_bits */
+ *dst = (*dst & (0xff << extra_bits)) | (last_c >> (8 - extra_bits));
+
+ /* Copy back first header+data byte */
+ dst = buffer + hdr_bytes;
+ *(dst++) = last_hdr_c | (src[0] << (8 - extra_bits));
+ *dst |= (src[0] >> (extra_bits)) & (0xff >> (8 - extra_bits));
+}
+
+/* put an (aligned) EGPRS data block with given bit-offset and
+ * bit-length into parent buffer */
+static void put_egprs_data_block(const TTCN_Buffer& aligned_data_block_buffer, unsigned int offset_bits,
+ unsigned int length_bits, TTCN_Buffer& dst_ttcn_buffer)
+{
+ const unsigned int initial_spare_bits = 6;
+ unsigned char *unaligned_buf = NULL;
+ char tmpbuf[120];
+ int tmplen = dst_ttcn_buffer.get_len();
+ //size_t max_length_bytes = (initial_spare_bits + length_bits + 7) / 8;
+ size_t length_bytes = tmplen + aligned_data_block_buffer.get_len();
+ size_t accepted_len = length_bytes;
+
+ //fprintf(stderr, "RLMAC: trying to allocate %u bytes\n", length_bytes);
+
+ /* API .get_end() is the only one I could find to access writeable
+ memory in the buffer. It points to the end. Hence, we first copy
+ (readonly) data to tmpbuf and later clear() so that .get_end()
+ provides us with a pointer to the start of the buffer. */
+ memcpy(tmpbuf, dst_ttcn_buffer.get_data(), tmplen);
+ dst_ttcn_buffer.clear();
+ dst_ttcn_buffer.get_end(unaligned_buf, accepted_len);
+ if (accepted_len < tmplen) {
+ fprintf(stderr, "RLMAC: ERROR! asked for %zu bytes but got %zu\n", length_bytes, accepted_len);
+ }
+ memcpy(unaligned_buf, tmpbuf, tmplen);
+
+ /* Copy the data out of the tvb to an aligned buffer */
+ clone_unaligned_buffer_lsbf(
+ offset_bits - initial_spare_bits, length_bytes,
+ aligned_data_block_buffer.get_data(),
+ unaligned_buf);
+
+ dst_ttcn_buffer.increase_length(length_bytes);
+}
/////////////////////
// DECODE
@@ -1078,8 +1170,15 @@ OCTETSTRING enc__RlcmacUlEgprsDataBlock(const RlcmacUlEgprsDataBlock& si)
{
RlcmacUlEgprsDataBlock in = si;
OCTETSTRING ret_val;
- TTCN_Buffer ttcn_buffer;
+ TTCN_Buffer ttcn_buffer, aligned_buffer;
int i;
+ unsigned int data_block_bits, data_block_offsets[2];
+ unsigned int num_calls;
+ CodingScheme mcs;
+ boolean tlli_ind, e;
+
+ mcs = RLCMAC__Templates::f__rlcmac__cps__htype__to__mcs(in.mac__hdr().cps(), in.mac__hdr().header__type());
+ //fprintf(stderr, "RLCMAC: infered MCS %s (%d)\n", mcs.enum_to_str(static_cast<CodingScheme::enum_type>(mcs.as_int())), mcs.as_int());
if (!in.blocks().is_bound()) {
/* we don't have nay blocks: Add length value (zero) */
@@ -1109,10 +1208,14 @@ OCTETSTRING enc__RlcmacUlEgprsDataBlock(const RlcmacUlEgprsDataBlock& si)
break; /* TODO: error */
}
+ /* Put first TI + E byte */
+ aligned_buffer.put_c(tlli_ind << 1 | e << 0); /* M=0, E=1 LEN=0 */
+ //printbuffer("After encoding first byte", aligned_buffer);
+
if (in.e() == false) {
/* Add LI octets, if any */
if (!in.blocks().is_bound()) {
- ttcn_buffer.put_c(0x01); /* M=0, E=1 LEN=0 */
+ aligned_buffer.put_c(0x01); /* M=0, E=1 LEN=0 */
} else {
for (i = 0; i < in.blocks().size_of(); i++) {
#if 0
@@ -1138,28 +1241,38 @@ OCTETSTRING enc__RlcmacUlEgprsDataBlock(const RlcmacUlEgprsDataBlock& si)
}
#endif
if (in.blocks()[i].hdr() != OMIT_VALUE) {
- in.blocks()[i].hdr()().encode(EgprsLlcBlockHdr_descr_, ttcn_buffer,
+ in.blocks()[i].hdr()().encode(EgprsLlcBlockHdr_descr_, aligned_buffer,
TTCN_EncDec::CT_RAW);
}
}
}
}
+
+
if (in.tlli__ind()) {
- ttcn_buffer.put_string(in.tlli());
+ aligned_buffer.put_string(in.tlli());
}
if (in.mac__hdr().pfi__ind()) {
- in.pfi().encode(RlcmacUlEgprsDataBlock_pfi_descr_, ttcn_buffer, TTCN_EncDec::CT_RAW);
+ in.pfi().encode(RlcmacUlEgprsDataBlock_pfi_descr_, aligned_buffer, TTCN_EncDec::CT_RAW);
}
+ //printbuffer("Before encoding EgprsLlc payload", aligned_buffer);
if (in.blocks().is_bound()) {
for (i = 0; i < in.blocks().size_of(); i++) {
if (!in.blocks()[i].is_bound())
continue;
- ttcn_buffer.put_string(in.blocks()[i].payload());
+ aligned_buffer.put_string(in.blocks()[i].payload());
}
}
+ //printbuffer("After encoding EgprsLlc payload", aligned_buffer);
+
+ setup_rlc_mac_priv(mcs, in.mac__hdr().header__type(), true,
+ &num_calls, &data_block_bits, data_block_offsets);
+ //printbuffer("before merging data block", ttcn_buffer);
+ put_egprs_data_block(aligned_buffer, data_block_offsets[0], data_block_bits, ttcn_buffer);
+ //printbuffer("after merging data block", ttcn_buffer);
ttcn_buffer.get_string(ret_val);
return ret_val;
diff --git a/library/RLCMAC_Templates.ttcn b/library/RLCMAC_Templates.ttcn
index d2174d7..38147f3 100644
--- a/library/RLCMAC_Templates.ttcn
+++ b/library/RLCMAC_Templates.ttcn
@@ -326,6 +326,31 @@ module RLCMAC_Templates {
}
}
+ /* Template for uplink Data block */
+ template RlcmacUlBlock t_RLCMAC_UL_EGPRS_DATA(CodingScheme mcs,
+ template uint5_t tfi, template uint4_t cv,
+ template uint11_t bsn1, template EgprsLlcBlocks blocks := {}) := {
+ data_egprs := {
+ mac_hdr := {
+ header_type := f_rlcmac_mcs2headertype(mcs),
+ tfi := tfi,
+ countdown := cv,
+ foi_si := '0'B,
+ r_ri := '0'B,
+ bsn1 := bsn1,
+ cps := f_rlcmac_mcs_to_cps(mcs, 1, false),
+ pfi_ind := false,
+ rsb := '0'B,
+ spb := '00'B
+ },
+ tlli_ind := false,
+ e := false,
+ tlli := omit,
+ pfi := omit,
+ blocks := blocks
+ }
+ }
+
template DlMacHeader t_RLCMAC_DlMacH(template MacPayloadType pt, template MacRrbp rrbp, template
uint3_t usf) := {
payload_type := pt,
@@ -519,4 +544,11 @@ uint3_t usf) := {
payload := data
}
+ /* Template for a LlcBlock (part of a LLC frame inside RlcMacEgprs?lDataBlock */
+ template EgprsLlcBlock t_RLCMAC_LLCBLOCK_EGPRS(octetstring data, boolean e := true) := {
+ /* let encoder figure out the header */
+ hdr := omit,
+ payload := data
+ }
+
} with { encode "RAW"; variant "FIELDORDER(msb)" }