How to obtain client from existing server connection?

[gkoh]

Use Case

NimBLE device is configured as a server and advertises. Smartphone client scans, can see peripheral device name and connects.

After connection, would like server to use existing connection to query (and display) client device name via service 0x1800 and characteristic 0x2A00.

What I've tried

• record peer ota address during server onConnect()
  • try NimBLEClient::connect() to this address
  • get 'already connected' due to ble_gap_conn_find_by_addr() finding the existing underlying connection
  • looked for others way to get a valid client object from the existing server handle, failed

What I hacked to prove it's possible

• modified NimBLEClient::connect() to:
  • use the ble_gap_conn_desc output of ble_gap_conn_find_by_addr() check
  • make the NimBLEClient connected with the details from the gap conn desc
  • used this client to get remote service and characteristic from the central
  • success

Possible Solutions

1. Nothing, I'm doing something crazy and weird
2. Modify NimBLEClient::connect() to allow and succeed with an already connected OTA address
3. Add a method to NimBLEServer for getting a properly connected NimBLEClient based on the underlying connection
4. Something else?

[h2zero]

Work in progress here: https://github.com/h2zero/esp-nimble-cpp/pull/156

[h2zero]

API added to master branch here: https://github.com/h2zero/NimBLE-Arduino/commit/6db036830c58ae85e3f691ceebada96e6d8ba4af

[gkoh]

API added to master branch here: 6db0368

Nice! Once again, much thanks and appreciation.