Consider the LoRa header when checking packet length

meshtastic · Sep 22, 2024 · 18aac0b · 18aac0b
1 parent 2e24d24
commit 18aac0b
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/src/mesh/RadioInterface.h b/src/mesh/RadioInterface.h
@@ -10,6 +10,7 @@
 #define MAX_TX_QUEUE 16 // max number of packets which can be waiting for transmission
 
 #define MAX_RHPACKETLEN 256
+#define LORA_HEADER_LENGTH 16
 
 #define PACKET_FLAGS_HOP_LIMIT_MASK 0x07
 #define PACKET_FLAGS_WANT_ACK_MASK 0x08

diff --git a/src/mesh/Router.cpp b/src/mesh/Router.cpp
@@ -475,7 +475,7 @@ meshtastic_Routing_Error perhapsEncode(meshtastic_MeshPacket *p)
             }
         } */
 
-        if (numbytes > MAX_RHPACKETLEN)
+        if (numbytes + LORA_HEADER_LENGTH > MAX_RHPACKETLEN)
             return meshtastic_Routing_Error_TOO_LARGE;
 
         // printBytes("plaintext", bytes, numbytes);
@@ -499,7 +499,7 @@ meshtastic_Routing_Error perhapsEncode(meshtastic_MeshPacket *p)
             p->decoded.portnum != meshtastic_PortNum_TRACEROUTE_APP && p->decoded.portnum != meshtastic_PortNum_NODEINFO_APP &&
             p->decoded.portnum != meshtastic_PortNum_ROUTING_APP && p->decoded.portnum != meshtastic_PortNum_POSITION_APP) {
             LOG_DEBUG("Using PKI!\n");
-            if (numbytes + 12 > MAX_RHPACKETLEN)
+            if (numbytes + LORA_HEADER_LENGTH + 12 > MAX_RHPACKETLEN)
                 return meshtastic_Routing_Error_TOO_LARGE;
             if (p->pki_encrypted && !memfll(p->public_key.bytes, 0, 32) &&
                 memcmp(p->public_key.bytes, node->user.public_key.bytes, 32) != 0) {