solution proposal for #42: discard slac_match confirmation if the des…

…tination MAC does not match
uhi22 · Oct 15, 2024 · c76baef · c76baef
1 parent 7a6c6d5
commit c76baef
Showing 1 changed file with 30 additions and 18 deletions.
diff --git a/ccs/homeplug.cpp b/ccs/homeplug.cpp
@@ -347,6 +347,7 @@ static void composeSlacMatchReq(void)
 static void evaluateSlacMatchCnf(void)
 {
    uint8_t i;
+   uint8_t blIsDestinationMacForMe;
    // The SLAC_MATCH.CNF contains the NMK and the NID.
    // We extract this information, so that we can use it for the CM_SET_KEY afterwards.
    // References: https://github.com/qca/open-plc-utils/blob/master/slac/evse_cm_slac_match.c
@@ -358,25 +359,36 @@ static void evaluateSlacMatchCnf(void)
    }
    else
    {
-      addToTrace(MOD_HOMEPLUG, "[PEVSLAC] received SLAC_MATCH.CNF");
-      for (i=0; i<7; i++)   // NID has 7 bytes
-      {
-         NID[i] = myethreceivebuffer[85+i];
-      }
-      for (i=0; i<16; i++)
-      {
-         NMK[i] = myethreceivebuffer[93+i];
+      blIsDestinationMacForMe = 1;
+      for (i=0; i<6; i++) {
+          /* compare all 6 bytes of the destination MAC with our own MAC */
+          if (myethreceivebuffer[i] != myMAC[i]) {
+              blIsDestinationMacForMe = 0; /* any mismatch -> it is not for me */
+          }
       }
-      addToTrace(MOD_HOMEPLUG, "[PEVSLAC] From SlacMatchCnf, got network membership key (NMK) and NID.");
-      // use the extracted NMK and NID to set the key in the adaptor:
-      composeSetKey();
-      addToTrace(MOD_HOMEPLUG, "[PEVSLAC] Checkpoint170: transmitting CM_SET_KEY.REQ");
-      setCheckpoint(170);
-      publishStatus("SLAC", "set key");
-      myEthTransmit();
-      if (pevSequenceState==STATE_WAITING_FOR_SLAC_MATCH_CNF)   // we were waiting for finishing the SLAC_MATCH.CNF and SET_KEY.REQ
-      {
-         slac_enterState(STATE_WAITING_FOR_RESTART2);
+      if (!blIsDestinationMacForMe) {
+          addToTrace(MOD_HOMEPLUG, "[PEVSLAC] received SLAC_MATCH.CNF but with foreign destination MAC. Ignoring.");
+      } else {
+          addToTrace(MOD_HOMEPLUG, "[PEVSLAC] received SLAC_MATCH.CNF");
+          for (i=0; i<7; i++)   // NID has 7 bytes
+          {
+             NID[i] = myethreceivebuffer[85+i];
+          }
+          for (i=0; i<16; i++)
+          {
+             NMK[i] = myethreceivebuffer[93+i];
+          }
+          addToTrace(MOD_HOMEPLUG, "[PEVSLAC] From SlacMatchCnf, got network membership key (NMK) and NID.");
+          // use the extracted NMK and NID to set the key in the adaptor:
+          composeSetKey();
+          addToTrace(MOD_HOMEPLUG, "[PEVSLAC] Checkpoint170: transmitting CM_SET_KEY.REQ");
+          setCheckpoint(170);
+          publishStatus("SLAC", "set key");
+          myEthTransmit();
+          if (pevSequenceState==STATE_WAITING_FOR_SLAC_MATCH_CNF)   // we were waiting for finishing the SLAC_MATCH.CNF and SET_KEY.REQ
+          {
+             slac_enterState(STATE_WAITING_FOR_RESTART2);
+          }
       }
    }
 }