Merge pull request #1928 from dz0ny/feat/grp-data-upstream

feat: Add support for PAYLOAD_TYPE_GRP_DATA

src/MeshCore.h

@@ -17,6 +17,7 @@
 #define PATH_HASH_SIZE       1
 
 #define MAX_PACKET_PAYLOAD  184
+#define MAX_GROUP_DATA_LENGTH  (MAX_PACKET_PAYLOAD - CIPHER_BLOCK_SIZE - 3)
 #define MAX_PATH_SIZE        64
 #define MAX_TRANS_UNIT      255
 
@@ -100,4 +101,4 @@ public:
   }
 };
 
-}
+}

src/Packet.h

@@ -22,7 +22,7 @@ namespace mesh {
 #define PAYLOAD_TYPE_ACK         0x03    // a simple ack
 #define PAYLOAD_TYPE_ADVERT      0x04    // a node advertising its Identity
 #define PAYLOAD_TYPE_GRP_TXT     0x05    // an (unverified) group text message (prefixed with channel hash, MAC) (enc data: timestamp, "name: msg")
-#define PAYLOAD_TYPE_GRP_DATA    0x06    // an (unverified) group datagram (prefixed with channel hash, MAC) (enc data: timestamp, blob)
+#define PAYLOAD_TYPE_GRP_DATA    0x06    // an (unverified) group datagram (prefixed with channel hash, MAC) (enc data: data_type(uint16), data_len, blob)
 #define PAYLOAD_TYPE_ANON_REQ    0x07    // generic request (prefixed with dest_hash, ephemeral pub_key, MAC) (enc data: ...)
 #define PAYLOAD_TYPE_PATH        0x08    // returned path (prefixed with dest/src hashes, MAC) (enc data: path, extra)
 #define PAYLOAD_TYPE_TRACE       0x09    // trace a path, collecting SNI for each hop

src/helpers/BaseChatMesh.cpp

@@ -353,8 +353,18 @@ int BaseChatMesh::searchChannelsByHash(const uint8_t* hash, mesh::GroupChannel d
 #endif
 
 void BaseChatMesh::onGroupDataRecv(mesh::Packet* packet, uint8_t type, const mesh::GroupChannel& channel, uint8_t* data, size_t len) {
-  uint8_t txt_type = data[4];
-  if (type == PAYLOAD_TYPE_GRP_TXT && len > 5 && (txt_type >> 2) == 0) {  // 0 = plain text msg
+  if (type == PAYLOAD_TYPE_GRP_TXT) {
+    if (len < 5) {
+      MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping short group text payload len=%d", (uint32_t)len);
+      return;
+    }
+
+    uint8_t txt_type = data[4];
+    if ((txt_type >> 2) != 0) {
+      MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping unsupported group text type=%d", (uint32_t)txt_type);
+      return;
+    }
+
     uint32_t timestamp;
     memcpy(&timestamp, data, 4);
 
@@ -363,6 +373,23 @@ void BaseChatMesh::onGroupDataRecv(mesh::Packet* packet, uint8_t type, const mes
 
     // notify UI  of this new message
     onChannelMessageRecv(channel, packet, timestamp, (const char *) &data[5]);  // let UI know
+  } else if (type == PAYLOAD_TYPE_GRP_DATA) {
+    if (len < 3) {
+      MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping short group data payload len=%d", (uint32_t)len);
+      return;
+    }
+
+    uint16_t data_type = ((uint16_t)data[0]) | (((uint16_t)data[1]) << 8);
+    uint8_t data_len = data[2];
+    size_t available_len = len - 3;
+
+    if (data_len > available_len) {
+      MESH_DEBUG_PRINTLN("onGroupDataRecv: dropping malformed group data type=%d len=%d available=%d",
+                         (uint32_t)data_type, (uint32_t)data_len, (uint32_t)available_len);
+      return;
+    }
+
+    onChannelDataRecv(channel, packet, data_type, &data[3], data_len);
   }
 }
 
@@ -454,6 +481,31 @@ bool BaseChatMesh::sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& chan
   return false;
 }
 
+bool BaseChatMesh::sendGroupData(mesh::GroupChannel& channel, uint16_t data_type, const uint8_t* data, int data_len) {
+  if (data_len < 0) {
+    MESH_DEBUG_PRINTLN("sendGroupData: invalid negative data_len=%d", data_len);
+    return false;
+  }
+  if (data_len > MAX_GROUP_DATA_LENGTH) {
+    MESH_DEBUG_PRINTLN("sendGroupData: data_len=%d exceeds max=%d", data_len, MAX_GROUP_DATA_LENGTH);
+    return false;
+  }
+
+  uint8_t temp[3 + MAX_GROUP_DATA_LENGTH];
+  temp[0] = (uint8_t)(data_type & 0xFF);
+  temp[1] = (uint8_t)(data_type >> 8);
+  temp[2] = (uint8_t)data_len;
+  if (data_len > 0) memcpy(&temp[3], data, data_len);
+
+  auto pkt = createGroupDatagram(PAYLOAD_TYPE_GRP_DATA, channel, temp, 3 + data_len);
+  if (pkt == NULL) {
+    MESH_DEBUG_PRINTLN("sendGroupData: unable to create group datagram, data_len=%d", data_len);
+    return false;
+  }
+  sendFloodScoped(channel, pkt);
+  return true;
+}
+
 bool BaseChatMesh::shareContactZeroHop(const ContactInfo& contact) {
   int plen = getBlobByKey(contact.id.pub_key, PUB_KEY_SIZE, temp_buf);  // retrieve last raw advert packet
   if (plen == 0) return false;  // not found

src/helpers/BaseChatMesh.h

@@ -111,6 +111,8 @@ protected:
   virtual uint32_t calcDirectTimeoutMillisFor(uint32_t pkt_airtime_millis, uint8_t path_len) const = 0;
   virtual void onSendTimeout() = 0;
   virtual void onChannelMessageRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint32_t timestamp, const char *text) = 0;
+  virtual void onChannelDataRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint16_t data_type,
+                                 const uint8_t* data, size_t data_len) {}
   virtual uint8_t onContactRequest(const ContactInfo& contact, uint32_t sender_timestamp, const uint8_t* data, uint8_t len, uint8_t* reply) = 0;
   virtual void onContactResponse(const ContactInfo& contact, const uint8_t* data, uint8_t len) = 0;
   virtual void handleReturnPathRetry(const ContactInfo& contact, const uint8_t* path, uint8_t path_len);
@@ -148,6 +150,7 @@ public:
   int  sendMessage(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& expected_ack, uint32_t& est_timeout);
   int  sendCommandData(const ContactInfo& recipient, uint32_t timestamp, uint8_t attempt, const char* text, uint32_t& est_timeout);
   bool sendGroupMessage(uint32_t timestamp, mesh::GroupChannel& channel, const char* sender_name, const char* text, int text_len);
+  bool sendGroupData(mesh::GroupChannel& channel, uint16_t data_type, const uint8_t* data, int data_len);
   int  sendLogin(const ContactInfo& recipient, const char* password, uint32_t& est_timeout);
   int  sendAnonReq(const ContactInfo& recipient, const uint8_t* data, uint8_t len, uint32_t& tag, uint32_t& est_timeout);
   int  sendRequest(const ContactInfo& recipient, uint8_t req_type, uint32_t& tag, uint32_t& est_timeout);

src/helpers/TxtDataHelpers.h

@@ -3,9 +3,10 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define TXT_TYPE_PLAIN          0    // a plain text message
-#define TXT_TYPE_CLI_DATA       1    // a CLI command
-#define TXT_TYPE_SIGNED_PLAIN   2    // plain text, signed by sender
+#define TXT_TYPE_PLAIN          0      // a plain text message
+#define TXT_TYPE_CLI_DATA       1      // a CLI command
+#define TXT_TYPE_SIGNED_PLAIN   2      // plain text, signed by sender
+#define DATA_TYPE_DEV           0xFFFF // developer namespace for experimenting with group/channel datagrams and building apps
 
 class StrHelper {
 public: