github.com/demonoid81/moby@v0.0.0-20200517203328-62dd8e17c460/pkg/aaparser/aaparser.go (about)

     1  // Package aaparser is a convenience package interacting with `apparmor_parser`.
     2  package aaparser // import "github.com/demonoid81/moby/pkg/aaparser"
     3  
     4  import (
     5  	"fmt"
     6  	"os/exec"
     7  	"strconv"
     8  	"strings"
     9  )
    10  
    11  const (
    12  	binary = "apparmor_parser"
    13  )
    14  
    15  // GetVersion returns the major and minor version of apparmor_parser.
    16  func GetVersion() (int, error) {
    17  	output, err := cmd("", "--version")
    18  	if err != nil {
    19  		return -1, err
    20  	}
    21  
    22  	return parseVersion(output)
    23  }
    24  
    25  // LoadProfile runs `apparmor_parser -Kr` on a specified apparmor profile to
    26  // replace the profile. The `-K` is necessary to make sure that apparmor_parser
    27  // doesn't try to write to a read-only filesystem.
    28  func LoadProfile(profilePath string) error {
    29  	_, err := cmd("", "-Kr", profilePath)
    30  	return err
    31  }
    32  
    33  // cmd runs `apparmor_parser` with the passed arguments.
    34  func cmd(dir string, arg ...string) (string, error) {
    35  	c := exec.Command(binary, arg...)
    36  	c.Dir = dir
    37  
    38  	output, err := c.CombinedOutput()
    39  	if err != nil {
    40  		return "", fmt.Errorf("running `%s %s` failed with output: %s\nerror: %v", c.Path, strings.Join(c.Args, " "), output, err)
    41  	}
    42  
    43  	return string(output), nil
    44  }
    45  
    46  // parseVersion takes the output from `apparmor_parser --version` and returns
    47  // a representation of the {major, minor, patch} version as a single number of
    48  // the form MMmmPPP {major, minor, patch}.
    49  func parseVersion(output string) (int, error) {
    50  	// output is in the form of the following:
    51  	// AppArmor parser version 2.9.1
    52  	// Copyright (C) 1999-2008 Novell Inc.
    53  	// Copyright 2009-2012 Canonical Ltd.
    54  
    55  	lines := strings.SplitN(output, "\n", 2)
    56  	words := strings.Split(lines[0], " ")
    57  	version := words[len(words)-1]
    58  
    59  	// split by major minor version
    60  	v := strings.Split(version, ".")
    61  	if len(v) == 0 || len(v) > 3 {
    62  		return -1, fmt.Errorf("parsing version failed for output: `%s`", output)
    63  	}
    64  
    65  	// Default the versions to 0.
    66  	var majorVersion, minorVersion, patchLevel int
    67  
    68  	majorVersion, err := strconv.Atoi(v[0])
    69  	if err != nil {
    70  		return -1, err
    71  	}
    72  
    73  	if len(v) > 1 {
    74  		minorVersion, err = strconv.Atoi(v[1])
    75  		if err != nil {
    76  			return -1, err
    77  		}
    78  	}
    79  	if len(v) > 2 {
    80  		patchLevel, err = strconv.Atoi(v[2])
    81  		if err != nil {
    82  			return -1, err
    83  		}
    84  	}
    85  
    86  	// major*10^5 + minor*10^3 + patch*10^0
    87  	numericVersion := majorVersion*1e5 + minorVersion*1e3 + patchLevel
    88  	return numericVersion, nil
    89  }