diff --git a/src/internal/poll/sock_cloexec.go b/src/internal/poll/sock_cloexec.go index e106b28377b66..cb40f47136453 100644 --- a/src/internal/poll/sock_cloexec.go +++ b/src/internal/poll/sock_cloexec.go @@ -5,7 +5,7 @@ // This file implements accept for platforms that provide a fast path for // setting SetNonblock and CloseOnExec. -//go:build dragonfly || freebsd || linux || netbsd || openbsd || solaris +//go:build dragonfly || freebsd || (linux && !arm) || netbsd || openbsd || solaris package poll diff --git a/src/internal/poll/sock_cloexec_accept.go b/src/internal/poll/sock_cloexec_accept.go new file mode 100644 index 0000000000000..4b86de59e0929 --- /dev/null +++ b/src/internal/poll/sock_cloexec_accept.go @@ -0,0 +1,51 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements accept for platforms that provide a fast path for +// setting SetNonblock and CloseOnExec, but don't necessarily have accept4. +// This is the code we used for accept in Go 1.17 and earlier. +// On Linux the accept4 system call was introduced in 2.6.28 kernel, +// and our minimum requirement is 2.6.32, so we simplified the function. +// Unfortunately, on ARM accept4 wasn't added until 2.6.36, so for ARM +// only we continue using the older code. + +//go:build linux && arm + +package poll + +import "syscall" + +// Wrapper around the accept system call that marks the returned file +// descriptor as nonblocking and close-on-exec. +func accept(s int) (int, syscall.Sockaddr, string, error) { + ns, sa, err := Accept4Func(s, syscall.SOCK_NONBLOCK|syscall.SOCK_CLOEXEC) + switch err { + case nil: + return ns, sa, "", nil + default: // errors other than the ones listed + return -1, sa, "accept4", err + case syscall.ENOSYS: // syscall missing + case syscall.EINVAL: // some Linux use this instead of ENOSYS + case syscall.EACCES: // some Linux use this instead of ENOSYS + case syscall.EFAULT: // some Linux use this instead of ENOSYS + } + + // See ../syscall/exec_unix.go for description of ForkLock. + // It is probably okay to hold the lock across syscall.Accept + // because we have put fd.sysfd into non-blocking mode. + // However, a call to the File method will put it back into + // blocking mode. We can't take that risk, so no use of ForkLock here. + ns, sa, err = AcceptFunc(s) + if err == nil { + syscall.CloseOnExec(ns) + } + if err != nil { + return -1, nil, "accept", err + } + if err = syscall.SetNonblock(ns, true); err != nil { + CloseFunc(ns) + return -1, nil, "setnonblock", err + } + return ns, sa, "", nil +} diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go index e1837b91a7b73..a5ebe5086a595 100644 --- a/src/syscall/syscall_linux.go +++ b/src/syscall/syscall_linux.go @@ -630,21 +630,6 @@ func anyToSockaddr(rsa *RawSockaddrAny) (Sockaddr, error) { return nil, EAFNOSUPPORT } -func Accept(fd int) (nfd int, sa Sockaddr, err error) { - var rsa RawSockaddrAny - var len _Socklen = SizeofSockaddrAny - nfd, err = accept4(fd, &rsa, &len, 0) - if err != nil { - return - } - sa, err = anyToSockaddr(&rsa) - if err != nil { - Close(nfd) - nfd = 0 - } - return -} - func Accept4(fd int, flags int) (nfd int, sa Sockaddr, err error) { var rsa RawSockaddrAny var len _Socklen = SizeofSockaddrAny diff --git a/src/syscall/syscall_linux_accept.go b/src/syscall/syscall_linux_accept.go new file mode 100644 index 0000000000000..66c0f84cb8e5d --- /dev/null +++ b/src/syscall/syscall_linux_accept.go @@ -0,0 +1,34 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// We require Linux kernel version 2.6.32. The accept4 system call was +// added in version 2.6.28, so in general we can use accept4. +// Unfortunately, for ARM only, accept4 was added in version 2.6.36. +// Handle that case here, by using a copy of the Accept function that +// we used in Go 1.17. + +//go:build linux && arm + +package syscall + +//sys accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) + +func Accept(fd int) (nfd int, sa Sockaddr, err error) { + var rsa RawSockaddrAny + var len _Socklen = SizeofSockaddrAny + // Try accept4 first for Android and newer kernels. + nfd, err = accept4(fd, &rsa, &len, 0) + if err == ENOSYS { + nfd, err = accept(fd, &rsa, &len) + } + if err != nil { + return + } + sa, err = anyToSockaddr(&rsa) + if err != nil { + Close(nfd) + nfd = 0 + } + return +} diff --git a/src/syscall/syscall_linux_accept4.go b/src/syscall/syscall_linux_accept4.go new file mode 100644 index 0000000000000..74898672c0466 --- /dev/null +++ b/src/syscall/syscall_linux_accept4.go @@ -0,0 +1,25 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file provides the Accept function used on all systems +// other than arm. See syscall_linux_accept.go for why. + +//go:build linux && !arm + +package syscall + +func Accept(fd int) (nfd int, sa Sockaddr, err error) { + var rsa RawSockaddrAny + var len _Socklen = SizeofSockaddrAny + nfd, err = accept4(fd, &rsa, &len, 0) + if err != nil { + return + } + sa, err = anyToSockaddr(&rsa) + if err != nil { + Close(nfd) + nfd = 0 + } + return +} diff --git a/src/syscall/zsyscall_linux_arm.go b/src/syscall/zsyscall_linux_arm.go index df79dbd0e1559..da16796abdf2b 100644 --- a/src/syscall/zsyscall_linux_arm.go +++ b/src/syscall/zsyscall_linux_arm.go @@ -1,4 +1,4 @@ -// mksyscall.pl -l32 -arm -tags linux,arm syscall_linux.go syscall_linux_arm.go +// mksyscall.pl -l32 -arm -tags linux,arm syscall_linux.go syscall_linux_arm.go syscall_linux_accept.go // Code generated by the command above; DO NOT EDIT. //go:build linux && arm @@ -1597,3 +1597,14 @@ func setrlimit(resource int, rlim *rlimit32) (err error) { } return } + +// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT + +func accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error) { + r0, _, e1 := Syscall(SYS_ACCEPT, uintptr(s), uintptr(unsafe.Pointer(rsa)), uintptr(unsafe.Pointer(addrlen))) + fd = int(r0) + if e1 != 0 { + err = errnoErr(e1) + } + return +}