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How to extract a fd using this library?

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#331 1 comment 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
go
Domain
networking

Research direction

Start at the websocket.NetConn entry point shown in the issue and trace how the returned net.Conn is represented. Check whether the connection implementation can expose the requested descriptor without relying on the shown reflection, and define completion as a supported way to obtain the integer fd.

Written by the indexing model from the issue text.

Description

enhancement

I am trying to keep track of some user state in my application and I would like to get an integer fd of the connection so I can hash and keep track of it in my data structure. I tried below and I get the following error

reflect: call of reflect.Value.FieldByName on zero Value

having this functionality in the connection struct would really help.

netConn := websocket.NetConn(context.Background(), conn, websocket.MessageText)
func GetFdFromConn(conn net.Conn) int {
	tcpConn := reflect.Indirect(reflect.ValueOf(conn)).FieldByName("conn")
	fdVal := tcpConn.FieldByName("fd")
	pfdVal := reflect.Indirect(fdVal).FieldByName("pfd")
	return int(pfdVal.FieldByName("Sysfd").Int())
}
Dominant language
Go
Stars
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Forks
377
PR merge metrics
No merged PRs in 30d

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