128 lines
4.4 KiB
Markdown
128 lines
4.4 KiB
Markdown
# Local Pairing To-dos
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- [Network Address / Peer Discovery](#network-address--peer-discovery)
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- [Network Debug Diagnostics](#network-debug-diagnostics)
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## Network Address / Peer Discovery
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Revamp the preferred network discovery process
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Note this functionality is pre-secret share so doesn't ...
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- **Pre-shared secret: scan the QR code first, containing the secret and then attempt to discover the other device(s)**
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- ⚠️ **Problem:** Only works if UDP discovery works. [See possible solution for UDP discovery failure mitigation](#udp-discovery-failure-mitigation)
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- Start pairing server on relevant device, listen to `0.0.0.0`.
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- get selected port number
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- get TLS pub key
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- get secret
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- Scan QR code which including:
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- selected port number
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- TLS pub key
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- secret
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- UDP discovery happens 🧙🪄✨
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- devices acquire ip addresses of peer(s), and themselves.
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- client device attempts connection as normal
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- **Post-shared secret, which is confirmed later with the QR code**
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- UDP discovery happens 🧙🪄✨
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- devices acquire ip addresses of peer(s), and themselves.
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- can also optionally give feedback to the user with the pairing options.
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- server device starts server listener, listen to known network ip address
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- get selected port number
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- get TLS pub key
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- get secret
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- Scan QR code which including:
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- selected port number
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- TLS pub key
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- secret
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- client device attempts connection as normal
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### Self IP address acquisition
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1. Ask network interface for its preferred outbound IP address
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- The process currently relied on
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- Add a required a self "confirmation" ping, to ensure the given address is network addressable.
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- On fail, fall through to stage 2
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2. device gets a list of its network addresses.
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- Use `netIfaces, err := net.Interfaces()` [See snippet](#get-all-network-addresses)
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- run filter for only local private net addrs
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- open listener on 0.0.0.0
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- make an outbound network call to all ips
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- call should include the addressing ip so device knows which address is network addressable
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- record all ip addresses that are able to ping the listener.
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- hopefully the list will only ever contain 1 IP address
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- On fail, fall through to stage 3
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3. Attempt discovery via UDP multicast
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- **Question :** How do **both** devices know when to start UDP discovery?
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- Perhaps the QR code device can add details to the application
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- no guarantee that both devices get an IP address
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- [See UDP discovery failure mitigation](#udp-discovery-failure-mitigation)
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## Network Debug Diagnostics
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We need to check a few things if a connection isn't working
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- What network ip address does the device think it has?
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- What is the port number the listener is listening on?
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- Can the device access its own network IP address?
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- Can a device find, and be found by, other devices?
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- attempt UDP discovery
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- What is the device's network connection(s) status?
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- `ipconfig` / `ifconfig`
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- Test each in series, all above functions
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- Capture everything, even errors
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- DO NOT early return errors, log the errors, proceed with the next function.
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- log all outputs to standard logger
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- log all outputs memory for export / return
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- When test suite is complete return log out put
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## Refs
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###### UDP discovery failure mitigation
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- Both devices listen on a tcp port chosen by the network interface
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- Attempt UDP discovery
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- In the UDP packet include:
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- the device's listener port number
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- ensure the notifier's id is stored for later connections via tcp
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- When peer A discovers peer B, peer A pings peer B's "confirmation" listener with peer B's IP address and network info about peer A
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- peer B attempts an outbound **TLS** connection to its own "confirmation" server, with a random code, to confirm its own IP address.
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###### Get all network addresses
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```go
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package test
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import (
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"fmt"
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"net"
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)
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func AllNetworkAddresses() error {
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netIfaces, err := net.Interfaces()
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if err != nil {
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return err
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}
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for _, i := range netIfaces {
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addrs, err := i.Addrs()
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if err != nil {
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return err
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}
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for _, addr := range addrs {
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var ip net.IP
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switch v := addr.(type) {
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case *net.IPNet:
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ip = v.IP
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case *net.IPAddr:
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ip = v.IP
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default:
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return fmt.Errorf("unknown ip type %s", v)
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}
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fmt.Print(ip)
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}
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}
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return nil
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}
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``` |