5 Jan
2023
5 Jan
'23
noon
dexter has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-pcu/+/30863 )
Change subject: bts: refuse to set invalid frame numbers
......................................................................
bts: refuse to set invalid frame numbers
A valid GSM frame ranges from 0 to 2715647. When using
set_current_frame_number() to set the current frame number (source
usually is the layer 1 and below) we should not allow invalid frame
numbers.
Note: this also fixes FnTest which uses invalid frame numbers for
testsing.
Change-Id: Iaae31b370fababba975d419b0d20ac15618c296e
Related: OS#5198
---
M src/bts.cpp
M tests/fn/FnTest.cpp
M tests/fn/FnTest.ok
3 files changed, 21 insertions(+), 14 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-pcu refs/changes/63/30863/1
diff --git a/src/bts.cpp b/src/bts.cpp
index cf39aa4..069758b 100644
--- a/src/bts.cpp
+++ b/src/bts.cpp
@@ -338,6 +338,13 @@
void bts_set_current_frame_number(struct gprs_rlcmac_bts *bts, uint32_t fn)
{
+ /* Refuse to set frame numbers that exceed the valid range */
+ if (fn > GSM_TDMA_HYPERFRAME) {
+ LOGP(DRLCMAC, LOGL_ERROR,
+ "cannot set frame number (%u) exceeds valid range (0-%u)\n", fn,
GSM_TDMA_HYPERFRAME);
+ return;
+ }
+
/* The UL frame numbers lag 3 behind the DL frames and the data
* indication is only sent after all 4 frames of the block have been
* received. Sometimes there is an idle frame between the end of one
diff --git a/tests/fn/FnTest.cpp b/tests/fn/FnTest.cpp
index e5ac46d..ae15164 100644
--- a/tests/fn/FnTest.cpp
+++ b/tests/fn/FnTest.cpp
@@ -92,13 +92,13 @@
fn = calc_fn(bts, RFN_MODULUS - 1);
OSMO_ASSERT(fn == 42431);
- set_fn(bts, RFN_MODULUS * 123 + 16);
+ set_fn(bts, RFN_MODULUS * 12 + 16);
fn = calc_fn(bts, RFN_MODULUS - 4);
- OSMO_ASSERT(fn == 5219132);
+ OSMO_ASSERT(fn == 509180);
- set_fn(bts, RFN_MODULUS * 123 + 451);
+ set_fn(bts, RFN_MODULUS * 12 + 451);
fn = calc_fn(bts, RFN_MODULUS - 175);
- OSMO_ASSERT(fn == 5218961);
+ OSMO_ASSERT(fn == 509009);
/* Lets check a special cornercase. We assume that
@@ -125,7 +125,7 @@
/* Also check with some corner case
* values where Fn and RFn reach its
* maximum/minimum valid range */
- set_fn(bts, GSM_MAX_FN);
+ set_fn(bts, GSM_MAX_FN-1);
fn = calc_fn(bts, RFN_MODULUS-1);
OSMO_ASSERT(fn == GSM_MAX_FN-1);
@@ -133,9 +133,9 @@
fn = calc_fn(bts, RFN_MODULUS-1);
OSMO_ASSERT(fn == GSM_MAX_FN-1);
- set_fn(bts, GSM_MAX_FN);
+ set_fn(bts, GSM_MAX_FN-1);
fn = calc_fn(bts, 0);
- OSMO_ASSERT(fn == GSM_MAX_FN);
+ OSMO_ASSERT(fn == GSM_MAX_FN-RFN_MODULUS*2);
set_fn(bts, 0);
fn = calc_fn(bts, 0);
diff --git a/tests/fn/FnTest.ok b/tests/fn/FnTest.ok
index be6400f..4884ca5 100644
--- a/tests/fn/FnTest.ok
+++ b/tests/fn/FnTest.ok
@@ -19,11 +19,11 @@
bts: fn=42433
rfn=42431 ==> fn=42431
-bts: fn=5219152
-rfn=42428 ==> fn=5219132
+bts: fn=509200
+rfn=42428 ==> fn=509180
-bts: fn=5219587
-rfn=42257 ==> fn=5218961
+bts: fn=509635
+rfn=42257 ==> fn=509009
bts: fn=0
rfn=42419 ==> fn=2715635
@@ -37,14 +37,14 @@
bts: fn=23
rfn=42390 ==> fn=2715606
-bts: fn=2715648
+bts: fn=2715647
rfn=42431 ==> fn=2715647
bts: fn=0
rfn=42431 ==> fn=2715647
-bts: fn=2715648
-rfn=0 ==> fn=2715648
+bts: fn=2715647
+rfn=0 ==> fn=2630784
bts: fn=0
rfn=0 ==> fn=0
--
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Gerrit-Project: osmo-pcu
Gerrit-Branch: master
Gerrit-Change-Id: Iaae31b370fababba975d419b0d20ac15618c296e
Gerrit-Change-Number: 30863
Gerrit-PatchSet: 1
Gerrit-Owner: dexter <pmaier(a)sysmocom.de>
Gerrit-MessageType: newchange