From ddfcc51b913a70da48102f64e18b34579dc3611c Mon Sep 17 00:00:00 2001 From: Ophestra Date: Mon, 7 Jul 2025 13:47:05 +0900 Subject: [PATCH] container: move capset implementation Signed-off-by: Ophestra --- container/capability.go | 45 +++++++++++++++++++++++++++++++++++++++++ container/syscall.go | 42 -------------------------------------- 2 files changed, 45 insertions(+), 42 deletions(-) create mode 100644 container/capability.go diff --git a/container/capability.go b/container/capability.go new file mode 100644 index 0000000..7c36ce9 --- /dev/null +++ b/container/capability.go @@ -0,0 +1,45 @@ +package container + +import ( + "syscall" + "unsafe" +) + +const ( + _LINUX_CAPABILITY_VERSION_3 = 0x20080522 + + PR_CAP_AMBIENT = 0x2f + PR_CAP_AMBIENT_RAISE = 0x2 + PR_CAP_AMBIENT_CLEAR_ALL = 0x4 + + CAP_SYS_ADMIN = 0x15 + CAP_SETPCAP = 0x8 +) + +type ( + capHeader struct { + version uint32 + pid int32 + } + + capData struct { + effective uint32 + permitted uint32 + inheritable uint32 + } +) + +// See CAP_TO_INDEX in linux/capability.h: +func capToIndex(cap uintptr) uintptr { return cap >> 5 } + +// See CAP_TO_MASK in linux/capability.h: +func capToMask(cap uintptr) uint32 { return 1 << uint(cap&31) } + +func capset(hdrp *capHeader, datap *[2]capData) error { + if _, _, errno := syscall.Syscall(syscall.SYS_CAPSET, + uintptr(unsafe.Pointer(hdrp)), + uintptr(unsafe.Pointer(&datap[0])), 0); errno != 0 { + return errno + } + return nil +} diff --git a/container/syscall.go b/container/syscall.go index c30aa8f..075da89 100644 --- a/container/syscall.go +++ b/container/syscall.go @@ -2,12 +2,6 @@ package container import ( "syscall" - "unsafe" -) - -const ( - CAP_SYS_ADMIN = 0x15 - CAP_SETPCAP = 0x8 ) const ( @@ -24,42 +18,6 @@ func SetDumpable(dumpable uintptr) error { return nil } -const ( - _LINUX_CAPABILITY_VERSION_3 = 0x20080522 - - PR_CAP_AMBIENT = 0x2f - PR_CAP_AMBIENT_RAISE = 0x2 - PR_CAP_AMBIENT_CLEAR_ALL = 0x4 -) - -type ( - capHeader struct { - version uint32 - pid int32 - } - - capData struct { - effective uint32 - permitted uint32 - inheritable uint32 - } -) - -// See CAP_TO_INDEX in linux/capability.h: -func capToIndex(cap uintptr) uintptr { return cap >> 5 } - -// See CAP_TO_MASK in linux/capability.h: -func capToMask(cap uintptr) uint32 { return 1 << uint(cap&31) } - -func capset(hdrp *capHeader, datap *[2]capData) error { - if _, _, errno := syscall.Syscall(syscall.SYS_CAPSET, - uintptr(unsafe.Pointer(hdrp)), - uintptr(unsafe.Pointer(&datap[0])), 0); errno != 0 { - return errno - } - return nil -} - // IgnoringEINTR makes a function call and repeats it if it returns an // EINTR error. This appears to be required even though we install all // signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.