network_analyzer_android
The Android implementation of network_analyzer,
written in Kotlin.
This package is endorsed: host applications depend on network_analyzer
only, and the Flutter tool wires this implementation in automatically.
Platform channel
Dart↔Kotlin messaging is generated by pigeon from
pigeons/messages.dart:
dart run pigeon --input pigeons/messages.dart
Outputs (lib/src/messages.g.dart, Messages.g.kt) are committed after
generation. Never hand-write channel code.
Permissions
Declared by this package and merged into every host application:
| Permission | Why | Protection level |
|---|---|---|
INTERNET |
Sending probes to a monitoring target | Normal |
ACCESS_NETWORK_STATE |
Reading the active network's transport type, link addresses and default route via ConnectivityManager |
Normal |
Nothing else is declared.
READ_PHONE_STATE is deliberately not declared
From API 30, refining a cellular connection to its generation
(TelephonyManager.getDataNetworkType) requires READ_PHONE_STATE — a
dangerous runtime permission. Declaring it here would push it onto every
host application that adds this plugin, to improve one label.
So the plugin does not declare it. Without the grant, a mobile connection is
reported as NetworkInterfaceType.cellular rather than guessed at. A host
application that has independently been granted READ_PHONE_STATE gets
cellular5g / cellular4g / cellular3g / cellular2g automatically, with
no extra configuration.
ICMP
ICMP monitoring uses an unprivileged ICMP datagram socket
(android.system.Os.socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP)), permitted
since Android 5. No NDK component, no root, and no shelling out to
/system/bin/ping.
IPv4 only in this version. On an IPv6-only network, ICMP returns
UnsupportedCapabilityFailure; TCP and UDP keep working.
Emulator caveat
QEMU's user-mode NAT does not forward ICMP echo to external hosts, so internet ICMP monitoring reports 100% loss on the emulator while gateway ICMP (the virtual router, 10.0.2.1) works. Emulator latency values are artifacts of the virtual NAT stack, not real measurements. Validate ICMP and any latency claim on a physical device.