A Go (golang) implementation of libcap: import "libcap/cap".

The API for this "libcap/cap" package is very similar to libcap.
I've included a substantial interoperability test that validate
libcap(c) and libcap/cap(go) have import/export text and binary
format compatibility.

My motivation for implementing a standalone Go package was for a
cross-compilation issue I ran into (Go is much more friendly for
cross-compilation by default, unless you need to use cgo).

Signed-off-by: Andrew G. Morgan <morgan@kernel.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/go/mknames.go b/go/mknames.go
new file mode 100644
index 0000000..d430815
--- /dev/null
+++ b/go/mknames.go
@@ -0,0 +1,85 @@
+// Program mknames parses the cap_names.h file and creates an equivalent names.go file.
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"strings"
+)
+
+var (
+	header = flag.String("header", "", "name of header file")
+)
+
+func main() {
+	flag.Parse()
+
+	if *header == "" {
+		log.Fatal("usage: mknames --header=.../cap_names.h")
+	}
+	d, err := ioutil.ReadFile(*header)
+	if err != nil {
+		log.Fatal("reading:", err)
+	}
+
+	b := bytes.NewBuffer(d)
+
+	var list []string
+	for {
+		line, err := b.ReadString('\n')
+		if err == io.EOF {
+			break
+		}
+		if !strings.Contains(line, `"`) {
+			continue
+		}
+		i := strings.Index(line, `"`)
+		line = line[i+1:]
+		i = strings.Index(line, `"`)
+		line = line[:i]
+		list = append(list, line)
+	}
+
+	// generate package file names.go
+	fmt.Print(`package cap
+
+/* ** DO NOT EDIT THIS FILE. IT WAS AUTO-GENERATED BY LIBCAP'S GO BUILDER (mknames.go) ** */
+
+// NamedCount holds the number of capabilities with official names.
+const NamedCount = `, len(list), `
+
+// CHOWN etc., are the named capability bits on this system. The
+// canonical source for each name is the "uapi/linux/capabilities.h"
+// file, which is hard-coded into this package.
+const (
+`)
+	bits := make(map[string]string)
+	for i, name := range list {
+		v := strings.ToUpper(strings.TrimPrefix(name, "cap_"))
+		bits[name] = v
+		if i == 0 {
+			fmt.Println(v, " Value =  iota")
+		} else {
+			fmt.Println(v)
+		}
+	}
+	fmt.Print(`)
+
+var names = map[Value]string{
+`)
+	for _, name := range list {
+		fmt.Printf("%s: %q,\n", bits[name], name)
+	}
+	fmt.Print(`}
+
+var bits = map[string]Value {
+`)
+	for _, name := range list {
+		fmt.Printf("%q: %s,\n", name, bits[name])
+	}
+	fmt.Println(`}`)
+}