syscall: unable to use the full length for abstract socket starting with null

[albertsundjaja]

Go version

go version go1.23.3 linux/amd64

Output of go env in your module/workspace:

GO111MODULE='on'
GOARCH='amd64'
GOBIN=''
GOCACHE='/home/albert/.cache/go-build'
GOENV='/home/albert/.config/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='amd64'
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/home/albert/go/pkg/mod'
GONOPROXY='bitbucket.org/vivcourt/*'
GONOSUMDB='bitbucket.org/vivcourt/*'
GOOS='linux'
GOPATH='/home/albert/go'
GOPRIVATE='bitbucket.org/vivcourt/*'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/home/albert/go/pkg/mod/golang.org/[email protected]'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/home/albert/go/pkg/mod/golang.org/[email protected]/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.23.3'
GODEBUG=''
GOTELEMETRY='local'
GOTELEMETRYDIR='/home/albert/.config/go/telemetry'
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='gcc'
CXX='g++'
CGO_ENABLED='1'
GOMOD='/home/albert/glue/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build3031541326=/tmp/go-build -gno-record-gcc-switches'

What did you do?

https://go.dev/play/p/Lro4QrH5-BK

What did you see happen?

padded addr1 (@begins-with-at) with length: 108
padded addr2 (begins-with-null) with length: 108
panic: listen unix begins-with-null: bind: invalid argument

goroutine 1 [running]:
main.main()
/tmp/sandbox3694864181/prog.go:27 +0x294

What did you expect to see?

both address (beginning with @ and null or 0) should be useable to specify abstract unix domain socket with length of 108 (full path length)

the issue seems to be this line of code that checks for @ for abstract domain socket but not for 0
https://github.com/golang/go/blob/master/src/syscall/syscall_linux.go#L557

considering how the next part of the code checks for 0 and sl > 3 https://github.com/golang/go/blob/master/src/syscall/syscall_linux.go#L569
I would expect that specifying 0 to indicate it's a domain socket to be a valid way of doing so

let me know if this is something that should be fixed, I would be more than happy to create a PR. Thanks!

[gabyhelp]

Related Issues

• syscall: incorrect length of abstract Unix domain socket paths beginning with null character #63579 (closed)
• syscall: support for abstract unix domain socket with len(name) == len(sa.raw.Path) #21965 (closed)
• syscall: support unix-domain socket pathname longer than system defined value #6895 (closed)
• length of SockaddrUnix is wrong for abstract paths #1427 (closed)
• syscall: wrong addrlen passed to bind()/connect()/sendto() for SockaddrUnix #15381 (closed)
• x/crypto: TestDialUnix and unnamed socket name in Go #31413 (closed)
• "throw: index out of range" and "unknown pc" running network tests on Virtuozzo-virtualized Linux/amd64 system #15 (closed)
• syscall: panic when syscall.ParseSocketControlMessage called #41522 (closed)

Related Code Changes

• syscall: allow abstract unix socket to use the full Path len
• syscall: implement Unix Socket for Windows

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[ianlancetaylor]

Sure, send a patch. Thanks.

[gopherbot]

Change https://go.dev/cl/637335 mentions this issue: syscall: allow \x00-prefixed unix abstract socket to use full path length