From 9f5f008aedc910ff0ce18bf3f92b9b74f0438bf8 Mon Sep 17 00:00:00 2001 From: Aravind Sirsikar Date: Tue, 30 Aug 2016 13:20:23 +0530 Subject: CSN1 decoding: add test to show bug in CSN_LEFT_ALIGNED_VAR_BMP CSN1 decoding currently contains an attempted read past vector boundaries in case of a starting bit offset != 0, so that the last amount of bits read should be < 8. In the case of CSN_LEFT_ALIGNED_VAR_BMP, the mod-8 calculation is flawed, and in what should be the final step of reading n < 8 bits, 8 bits are read instead of n (with an extraneous read of n bits following after that). This leads to -EINVAL being returned by bitvec_get_bit_pos() and bogus resulting data. Add testCsnLeftAlignedVarBmpBounds() in RLCMACTest.cpp to show and expect this bug. The test's expectation shall be corrected along with the bug fix in a subsequent commit. Related: OS#1805 Tweaked-by: Neels Hofmeyr Change-Id: I4641f5d1d49f66cb1a5cd813befb3a2a266001b0 --- tests/rlcmac/RLCMACTest.cpp | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/tests/rlcmac/RLCMACTest.cpp b/tests/rlcmac/RLCMACTest.cpp index 466b89e5..f633dd82 100644 --- a/tests/rlcmac/RLCMACTest.cpp +++ b/tests/rlcmac/RLCMACTest.cpp @@ -30,6 +30,7 @@ extern const struct log_info gprs_log_info; #include "pcu_vty.h" #include #include +#include #include } using namespace std; @@ -211,6 +212,26 @@ void testRlcMacUplink() bitvec_free(resultVector); } +void testCsnLeftAlignedVarBmpBounds() +{ + bitvec *vector = bitvec_alloc(23); + + bitvec_unhex(vector, "40200bffd161003e0e519ffffffb800000000000000000"); + RlcMacUplink_t data; + + EGPRS_AckNack_Desc_t *urbb = + &data.u.Egprs_Packet_Downlink_Ack_Nack.EGPRS_AckNack.Desc; + decode_gsm_rlcmac_uplink(vector, &data); + + /* + * TODO: URBB len is decoded as 102 bits. So 96 + 6 bits = 12 bytes + 6 + * bits should be decoded. The 13th byte should end up as 0x00, but we + * see data coming from bitvec_get_bit_pos() returning -EINVAL. + */ + OSMO_ASSERT(!strcmp(osmo_hexdump(urbb->URBB, 13), + "7f ff ff ee 00 00 00 00 00 00 00 00 ea ")); +} + int main(int argc, char *argv[]) { osmo_init_logging(&gprs_log_info); @@ -218,5 +239,5 @@ int main(int argc, char *argv[]) //printSizeofRLCMAC(); testRlcMacDownlink(); testRlcMacUplink(); - + testCsnLeftAlignedVarBmpBounds(); } -- cgit v1.2.3