diff options
Diffstat (limited to 'sd_id128/sd_id128.go')
| -rw-r--r-- | sd_id128/sd_id128.go | 222 |
1 files changed, 0 insertions, 222 deletions
diff --git a/sd_id128/sd_id128.go b/sd_id128/sd_id128.go deleted file mode 100644 index 063a4d4..0000000 --- a/sd_id128/sd_id128.go +++ /dev/null @@ -1,222 +0,0 @@ -// Copyright 2016 Luke Shumaker -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -// Package sd_id128 provides functions for dealing with 128-bit IDs. -package sd_id128 - -import ( - "crypto/rand" - "errors" - "os" - "strings" -) - -var ( - ErrInvalid = errors.New("Invalid ID") - ErrNone = errors.New("No Invocation ID set") -) - -type ID128 [16]byte - -// String formats the ID as a hexadecimal number. -func (id ID128) String() string { - var s [32]byte - for n := range id { - s[n*2] = hexchar(id[n] >> 4) - s[n*2+1] = hexchar(id[n] & 0xF) - } - return string(s[:]) -} - -// UUID formats the ID as a UUID string. -func (id ID128) UUID() string { - var s [36]byte - k := 0 - for n := range id { - switch n { - case 4, 6, 8, 10: - s[k] = '-' - k++ - } - s[k] = hexchar(id[n] >> 4) - k++ - s[k] = hexchar(id[n] & 0xF) - k++ - } - return string(s[:]) -} - -// Parse parses a 128-bit ID represented either as a hexadecimal -// number, or as a UUID string (that is, a hexadecimal number with -// hyphens inserted at positions 8, 12, 18, and 23). -func Parse(s string) (ID128, error) { - ret := ID128{} - isGuid := false - - i := 0 - n := 0 - for n < 16 { - if s[i] == '-' { - if i == 8 { - isGuid = true - } else if i == 13 || i == 18 || i == 23 { - if !isGuid { - return ID128{}, ErrInvalid - } - } else { - return ID128{}, ErrInvalid - } - i++ - } else { - if i+2 >= len(s) { - return ID128{}, ErrInvalid - } - - a, err := unhexchar(s[i]) - i++ - if err != nil { - return ID128{}, err - } - - b, err := unhexchar(s[i]) - i++ - if err != nil { - return ID128{}, err - } - - ret[n] = (a << 4) | b - n++ - } - } - - if !((i == 36 && isGuid) || (i == 32 && !isGuid)) { - return ID128{}, ErrInvalid - } - if i != len(s) { - return ID128{}, ErrInvalid - } - - return ret, nil -} - -// ParsePlain is like Parse, but only accepts hexadecimal numbers, not -// UUID-formatted strings. -func ParsePlain(s string) (ID128, error) { - if len(s) != 32 { - return ID128{}, ErrInvalid - } - return Parse(s) -} - -// ParseUUID is like Parse, but only accepts UUID-formatted strings, -// not hexadecimal numbers. -func ParseUUID(s string) (ID128, error) { - if len(s) != 36 { - return ID128{}, ErrInvalid - } - return Parse(s) -} - -// GetRandomID generates a random v4 UUID (122 random bits). -func GetRandomID() (ID128, error) { - var id ID128 - _, err := rand.Read(id[:]) - if err != nil { - return ID128{}, err - } - - // Turn this in to a valid v4 UUID, to be nice. - - // Set UUID version to 4 --- truly random generation - id[6] = (id[6] & 0x0F) | 0x40 - - // Set the UUID variant to DCE - id[8] = (id[8] & 0x3F) | 0x80 - - return id, nil -} - -var cachedMachineID ID128 - -// GetMachineID returns a unique identifier for this machine. -// -// This is read as a plain hexadecimal number (with an optional -// trailing newline) from "/etc/machine-id". -func GetMachineID() (ID128, error) { - if cachedMachineID == (ID128{}) { - str, err := readfile("/etc/machine-id") - if err != nil { - return ID128{}, err - } - id, err := ParsePlain(strings.TrimSuffix(str, "\n")) - if err != nil { - return ID128{}, err - } - if id == (ID128{}) { - return ID128{}, ErrInvalid - } - cachedMachineID = id - } - return cachedMachineID, nil -} - -var cachedBootID ID128 - -// GetBootID returns a unique identifier for this boot. -// -// This is read as a UUID (with trailing newline) from -// "/proc/sys/kernel/random/boot_id". -func GetBootID() (ID128, error) { - if cachedBootID == (ID128{}) { - str, err := readfile("/proc/sys/kernel/random/boot_id") - if err != nil { - return ID128{}, err - } - id, err := ParseUUID(strings.TrimSuffix(str, "\n")) - if err != nil { - return ID128{}, err - } - cachedBootID = id - } - return cachedBootID, nil -} - -var cachedInvocationID ID128 - -// GetInvocationID returns a unique identifier for this invocation of -// the currently executed service. -// -// This is read from the "INVOCATION_ID" environment variable, which -// is expected to be set by the service manager. -// -// The error returned is ErrNone if the service manager did not set -// INVOCATION_ID, or ErrInvalid if the value of INVOCATION_ID could -// not be parsed. -func GetInvocationID() (ID128, error) { - if cachedInvocationID == (ID128{}) { - // BUG(lukeshu): GetInvocationID should distrust the - // environment in certain situations, similarly to GNU - // libc secure_getenv. - str, have := os.LookupEnv("INVOCATION_ID") - if !have { - return ID128{}, ErrNone - } - t, err := Parse(str) - if err != nil { - return ID128{}, err - } - cachedInvocationID = t - } - return cachedInvocationID, nil -} |