Refine Sntp_ConvertToUnixTime (#105)

Refine Sntp_ConvertToUnixTime

We do not need uint64_t for Unix timestamp as we can fit the time till
7 Feb 2106 06:28:15 in uint32_t and beyond that we cannot differentiate
between NTP era 0 and era 1 timestamps.

Signed-off-by: Gaurav Aggarwal <[email protected]>

Author: aggarg

.github/workflows/ci.yml

@@ -97,9 +97,8 @@ jobs:
       - name: Run Coverage
         run: |
           make -C build/ coverage
-          declare -a EXCLUDE=("\*test\*" "\*CMakeCCompilerId.c")
-          echo ${EXCLUDE[@]} | xargs lcov --rc  branch_coverage=1 --ignore-errors empty  --ignore-errors source -r build/coverage.info -o build/coverage.info
-          lcov --rc  branch_coverage=1 --ignore-errors empty --ignore-errors source --list build/coverage.info
+          lcov --rc  branch_coverage=1 -r build/coverage.info -o build/coverage.info
+          lcov --rc  branch_coverage=1 --summary build/coverage.info
 
       - name: Check Coverage
         uses: FreeRTOS/CI-CD-Github-Actions/coverage-cop@main
@@ -126,14 +125,14 @@ jobs:
           path: ./
 
   formatting:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
       - name: Check formatting
         uses: FreeRTOS/CI-CD-Github-Actions/formatting@main
         with:
           path: ./
-          exclude-dirs: .git
+          exclude-dirs: .git, test/unit-test/CMock
 
   git-secrets:
     runs-on: ubuntu-latest
@@ -207,7 +206,7 @@ jobs:
 
   proof_ci:
     if: ${{ github.event.pull_request }} || ${{ github.event.workflow }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
       - name: Set up CBMC runner
         uses: FreeRTOS/CI-CD-Github-Actions/set_up_cbmc_runner@main

.github/workflows/formatting.yml

@@ -16,7 +16,7 @@ jobs:
     if: ${{ github.event.issue.pull_request &&
         ( ( github.event.comment.body == '/bot run uncrustify' ) ||
           ( github.event.comment.body == '/bot run formatting' ) ) }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     steps:
     - name: Apply Formatting Fix
       uses: FreeRTOS/CI-CD-Github-Actions/formatting-bot@main

docs/doxygen/code_examples/example_sntp_client_posix.c

@@ -139,7 +139,7 @@ static void sntpClient_SetTime( const SntpServerInfo_t * pTimeServer,
                                 SntpLeapSecondInfo_t leapSecondInfo )
 {
     /* @[code_example_sntp_converttounixtime] */
-    UnixTime_t unixSecs;
+    uint32_t unixSecs;
     uint32_t unixMs;
     SntpStatus_t status = Sntp_ConvertToUnixTime( pServerTime, &unixSecs, &unixMs );
 

docs/doxygen/images/Ntp_To_Unix_Time.png

@@ -15,11 +15,11 @@
     <tr>
         <td>core_sntp_serializer.c</td>
         <td><center>1.0K</center></td>
-        <td><center>0.8K</center></td>
+        <td><center>0.7K</center></td>
     </tr>
     <tr>
         <td><b>Total estimates</b></td>
         <td><b><center>2.7K</center></b></td>
-        <td><b><center>2.1K</center></b></td>
+        <td><b><center>2.0K</center></b></td>
     </tr>
 </table>

docs/doxygen/include/size_table.md

@@ -812,7 +812,7 @@ SntpStatus_t Sntp_CalculatePollInterval( uint16_t clockFreqTolerance,
 }
 
 SntpStatus_t Sntp_ConvertToUnixTime( const SntpTimestamp_t * pSntpTime,
-                                     UnixTime_t * pUnixTimeSecs,
+                                     uint32_t * pUnixTimeSecs,
                                      uint32_t * pUnixTimeMicrosecs )
 {
     SntpStatus_t status = SntpSuccess;
@@ -821,24 +821,20 @@ SntpStatus_t Sntp_ConvertToUnixTime( const SntpTimestamp_t * pSntpTime,
     {
         status = SntpErrorBadParameter;
     }
-    else
+
+    if( status == SntpSuccess )
     {
-        /* Handle case when timestamp represents date in SNTP era 1
-         * (i.e. time from 7 Feb 2036 6:28:16 UTC onwards). */
-        if( pSntpTime->seconds <= SNTP_TIME_AT_LARGEST_UNIX_TIME_SECS )
+        /* Handle case when SNTP timestamp is in SNTP era 0 time range
+         * (i.e. time before 7 Feb 2036 6:28:15 UTC). */
+        if( pSntpTime->seconds >= SNTP_TIME_AT_UNIX_EPOCH_SECS )
         {
-            /* Unix Time ( seconds ) = Seconds Duration in
-             *                         [UNIX epoch, SNTP Era 1 Epoch Time]
-             *                                        +
-             *                           Sntp Time since Era 1 Epoch
-             */
-            *pUnixTimeSecs = ( UnixTime_t ) ( UNIX_TIME_SECS_AT_SNTP_ERA_1_SMALLEST_TIME + ( UnixTime_t ) ( pSntpTime->seconds ) );
+            *pUnixTimeSecs = pSntpTime->seconds - SNTP_TIME_AT_UNIX_EPOCH_SECS;
         }
-
-        /* Handle case when SNTP timestamp is in SNTP era 1 time range. */
-        if( pSntpTime->seconds >= SNTP_TIME_AT_UNIX_EPOCH_SECS )
+        else
         {
-            *pUnixTimeSecs = ( UnixTime_t ) ( ( UnixTime_t ) ( pSntpTime->seconds ) - SNTP_TIME_AT_UNIX_EPOCH_SECS );
+            /* Handle case when timestamp represents date in SNTP era 1
+             * (i.e. time from 7 Feb 2036 6:28:16 UTC onwards). */
+            *pUnixTimeSecs = UNIX_TIME_SECS_AT_SNTP_ERA_1_SMALLEST_TIME + pSntpTime->seconds;
         }
 
         /* Convert SNTP fractions to microseconds for UNIX time. */

source/core_sntp_serializer.c

@@ -43,20 +43,6 @@
 #endif
 /* *INDENT-ON* */
 
-/**
- * @brief Type representing seconds since Unix epoch (January 1, 1970 UTC).
- *
- * The width of this type depends on the configuration macro USE_LEGACY_TIME_API:
- * - If USE_LEGACY_TIME_API is defined, a 32-bit unsigned integer is used.
- *   This limits date representation to the year 2038 (Y2038 limitation).
- * - Otherwise, a 64-bit unsigned integer is used for Y2038 compliance.
- */
-#ifdef USE_LEGACY_TIME_API
-    typedef uint32_t   UnixTime_t; /**< 32-bit Unix time for legacy systems. */
-#else
-    typedef uint64_t   UnixTime_t; /**< 64-bit Unix time for Y2038 compliance. */
-#endif
-
 /**
  * @ingroup sntp_constants
  * @brief The base packet size of request and response of the (S)NTP protocol.
@@ -504,15 +490,7 @@ SntpStatus_t Sntp_CalculatePollInterval( uint16_t clockFreqTolerance,
  * @brief Utility to convert SNTP timestamp (that uses 1st Jan 1900 as the epoch) to
  * UNIX timestamp (that uses 1st Jan 1970 as the epoch).
  *
- * @note This function converts SNTP timestamps to UNIX time supporting both 32-bit and
- * 64-bit representations based on the configuration macro USE_LEGACY_TIME_API.
- *
- * - If USE_LEGACY_TIME_API is defined, the conversion is limited to the date range
- *   from 1st Jan 1970 0h 0m 0s (UNIX epoch) to 19th Jan 2038 3h 14m 7s, due to the
- *   32-bit width limitation.
- *
- * - If USE_LEGACY_TIME_API is not defined, 64-bit UNIX time representation is used,
- *   allowing conversion of SNTP timestamps beyond the year 2038 (Y2038 problem mitigated).
+ * Refer to (this image)[docs/doxygen/images/Ntp_To_Unix_Time.png].
  *
  * @note The function also correctly handles SNTP era overflow (from 7 Feb 2036 6h 28m 16s,
  * i.e., SNTP era 1) to ensure accurate conversion across SNTP eras.
@@ -529,7 +507,7 @@ SntpStatus_t Sntp_CalculatePollInterval( uint16_t clockFreqTolerance,
  */
 /* @[define_sntp_converttounixtime] */
 SntpStatus_t Sntp_ConvertToUnixTime( const SntpTimestamp_t * pSntpTime,
-                                     UnixTime_t * pUnixTimeSecs,
+                                     uint32_t * pUnixTimeSecs,
                                      uint32_t * pUnixTimeMicrosecs );
 /* @[define_sntp_converttounixtime] */
 

source/include/core_sntp_serializer.h

@@ -32,12 +32,12 @@
 void harness()
 {
     SntpTimestamp_t * pSntpTime;
-    UnixTime_t * pUnixTimeSecs;
+    uint32_t * pUnixTimeSecs;
     uint32_t * pUnixTimeMicrosecs;
     SntpStatus_t sntpStatus;
 
     pSntpTime = malloc( sizeof( SntpTimestamp_t ) );
-    pUnixTimeSecs = malloc( sizeof( UnixTime_t ) );
+    pUnixTimeSecs = malloc( sizeof( uint32_t ) );
     pUnixTimeMicrosecs = malloc( sizeof( uint32_t ) );
 
     sntpStatus = Sntp_ConvertToUnixTime( pSntpTime, pUnixTimeSecs, pUnixTimeMicrosecs );

test/cbmc/proofs/Sntp_ConvertToUnixTime/Sntp_ConvertToUnixTime_harness.c

@@ -877,7 +877,7 @@ void test_ConvertToUnixTime_InvalidParams( void )
 
     /* Use same memory for UNIX seconds and microseconds as we are not
      * testing those values. */
-    UnixTime_t unixTime;
+    uint32_t unixTime;
     uint32_t unixTimeMs;
 
     /* Test with NULL SNTP time. */
@@ -900,7 +900,7 @@ void test_ConvertToUnixTime_InvalidParams( void )
 void test_ConvertToUnixTime_Nominal( void )
 {
     SntpTimestamp_t sntpTime = TEST_TIMESTAMP;
-    UnixTime_t unixTimeSecs;
+    uint32_t unixTimeSecs;
     uint32_t unixTimeMs;
 
 #define TEST_SNTP_TO_UNIX_CONVERSION( sntpTimeSecs, sntpTimeFracs,               \

test/unit-test/core_sntp_serializer_utest.c

@@ -15,11 +15,9 @@ execute_process( COMMAND lcov --directory ${CMAKE_BINARY_DIR}
                          --initial
                          --capture
                          --rc branch_coverage=1
-                         --ignore-errors empty
-                         --ignore-errors source
                          --rc genhtml_branch_coverage=1
                          --output-file=${CMAKE_BINARY_DIR}/base_coverage.info
-                         --quiet
+                         --include "*source*"
         )
 file(GLOB files "${CMAKE_BINARY_DIR}/bin/tests/*")
 
@@ -49,13 +47,11 @@ execute_process(COMMAND ruby
 execute_process(
             COMMAND lcov --capture
                          --rc branch_coverage=1
-                         --ignore-errors empty
-                         --ignore-errors source
                          --rc genhtml_branch_coverage=1
                          --base-directory ${CMAKE_BINARY_DIR}
                          --directory ${CMAKE_BINARY_DIR}
                          --output-file ${CMAKE_BINARY_DIR}/second_coverage.info
-                         --quiet
+                         --include "*source*"
         )
 
 # combile baseline results (zeros) with the one after running the tests
@@ -67,16 +63,10 @@ execute_process(
                          --output-file ${CMAKE_BINARY_DIR}/coverage.info
                          --no-external
                          --rc branch_coverage=1
-                         --ignore-errors empty
-                         --ignore-errors source
-                         --quiet
         )
 execute_process(
             COMMAND genhtml --rc branch_coverage=1
-                            --ignore-errors empty
-                            --ignore-errors source
                             --branch-coverage
                             --output-directory ${CMAKE_BINARY_DIR}/coverage
                                 ${CMAKE_BINARY_DIR}/coverage.info
-                            --quiet
-        )
+         )