diff options
Diffstat (limited to 'vendor/github.com/cilium/ebpf/internal/version.go')
-rw-r--r-- | vendor/github.com/cilium/ebpf/internal/version.go | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/internal/version.go b/vendor/github.com/cilium/ebpf/internal/version.go new file mode 100644 index 000000000..370e01e44 --- /dev/null +++ b/vendor/github.com/cilium/ebpf/internal/version.go @@ -0,0 +1,122 @@ +package internal + +import ( + "fmt" + "sync" + + "github.com/cilium/ebpf/internal/unix" +) + +const ( + // Version constant used in ELF binaries indicating that the loader needs to + // substitute the eBPF program's version with the value of the kernel's + // KERNEL_VERSION compile-time macro. Used for compatibility with BCC, gobpf + // and RedSift. + MagicKernelVersion = 0xFFFFFFFE +) + +var ( + kernelVersion = struct { + once sync.Once + version Version + err error + }{} +) + +// A Version in the form Major.Minor.Patch. +type Version [3]uint16 + +// NewVersion creates a version from a string like "Major.Minor.Patch". +// +// Patch is optional. +func NewVersion(ver string) (Version, error) { + var major, minor, patch uint16 + n, _ := fmt.Sscanf(ver, "%d.%d.%d", &major, &minor, &patch) + if n < 2 { + return Version{}, fmt.Errorf("invalid version: %s", ver) + } + return Version{major, minor, patch}, nil +} + +// NewVersionFromCode creates a version from a LINUX_VERSION_CODE. +func NewVersionFromCode(code uint32) Version { + return Version{ + uint16(uint8(code >> 16)), + uint16(uint8(code >> 8)), + uint16(uint8(code)), + } +} + +func (v Version) String() string { + if v[2] == 0 { + return fmt.Sprintf("v%d.%d", v[0], v[1]) + } + return fmt.Sprintf("v%d.%d.%d", v[0], v[1], v[2]) +} + +// Less returns true if the version is less than another version. +func (v Version) Less(other Version) bool { + for i, a := range v { + if a == other[i] { + continue + } + return a < other[i] + } + return false +} + +// Unspecified returns true if the version is all zero. +func (v Version) Unspecified() bool { + return v[0] == 0 && v[1] == 0 && v[2] == 0 +} + +// Kernel implements the kernel's KERNEL_VERSION macro from linux/version.h. +// It represents the kernel version and patch level as a single value. +func (v Version) Kernel() uint32 { + + // Kernels 4.4 and 4.9 have their SUBLEVEL clamped to 255 to avoid + // overflowing into PATCHLEVEL. + // See kernel commit 9b82f13e7ef3 ("kbuild: clamp SUBLEVEL to 255"). + s := v[2] + if s > 255 { + s = 255 + } + + // Truncate members to uint8 to prevent them from spilling over into + // each other when overflowing 8 bits. + return uint32(uint8(v[0]))<<16 | uint32(uint8(v[1]))<<8 | uint32(uint8(s)) +} + +// KernelVersion returns the version of the currently running kernel. +func KernelVersion() (Version, error) { + kernelVersion.once.Do(func() { + kernelVersion.version, kernelVersion.err = detectKernelVersion() + }) + + if kernelVersion.err != nil { + return Version{}, kernelVersion.err + } + return kernelVersion.version, nil +} + +// detectKernelVersion returns the version of the running kernel. +func detectKernelVersion() (Version, error) { + vc, err := vdsoVersion() + if err != nil { + return Version{}, err + } + return NewVersionFromCode(vc), nil +} + +// KernelRelease returns the release string of the running kernel. +// Its format depends on the Linux distribution and corresponds to directory +// names in /lib/modules by convention. Some examples are 5.15.17-1-lts and +// 4.19.0-16-amd64. +func KernelRelease() (string, error) { + var uname unix.Utsname + if err := unix.Uname(&uname); err != nil { + return "", fmt.Errorf("uname failed: %w", err) + } + + return unix.ByteSliceToString(uname.Release[:]), nil +} |