github.com/moby/docker@v26.1.3+incompatible/oci/oci.go (about)

     1  package oci // import "github.com/docker/docker/oci"
     2  
     3  import (
     4  	"fmt"
     5  	"regexp"
     6  	"strconv"
     7  
     8  	specs "github.com/opencontainers/runtime-spec/specs-go"
     9  )
    10  
    11  // TODO verify if this regex is correct for "a" (all);
    12  //
    13  // The docs (https://github.com/torvalds/linux/blob/v5.10/Documentation/admin-guide/cgroup-v1/devices.rst) describe:
    14  // "'all' means it applies to all types and all major and minor numbers", and shows an example
    15  // that *only* passes `a` as value: `echo a > /sys/fs/cgroup/1/devices.allow, which would be
    16  // the "implicit" equivalent of "a *:* rwm". Source-code also looks to confirm this, and returns
    17  // early for "a" (all); https://github.com/torvalds/linux/blob/v5.10/security/device_cgroup.c#L614-L642
    18  var deviceCgroupRuleRegex = regexp.MustCompile("^([acb]) ([0-9]+|\\*):([0-9]+|\\*) ([rwm]{1,3})$") //nolint: gosimple
    19  
    20  // SetCapabilities sets the provided capabilities on the spec
    21  // All capabilities are added if privileged is true.
    22  func SetCapabilities(s *specs.Spec, caplist []string) error {
    23  	if s.Process == nil {
    24  		s.Process = &specs.Process{}
    25  	}
    26  	s.Process.Capabilities = &specs.LinuxCapabilities{
    27  		Effective: caplist,
    28  		Bounding:  caplist,
    29  		Permitted: caplist,
    30  	}
    31  	return nil
    32  }
    33  
    34  // AppendDevicePermissionsFromCgroupRules takes rules for the devices cgroup to append to the default set
    35  func AppendDevicePermissionsFromCgroupRules(devPermissions []specs.LinuxDeviceCgroup, rules []string) ([]specs.LinuxDeviceCgroup, error) {
    36  	for _, deviceCgroupRule := range rules {
    37  		ss := deviceCgroupRuleRegex.FindAllStringSubmatch(deviceCgroupRule, -1)
    38  		if len(ss) == 0 || len(ss[0]) != 5 {
    39  			return nil, fmt.Errorf("invalid device cgroup rule format: '%s'", deviceCgroupRule)
    40  		}
    41  		matches := ss[0]
    42  
    43  		dPermissions := specs.LinuxDeviceCgroup{
    44  			Allow:  true,
    45  			Type:   matches[1],
    46  			Access: matches[4],
    47  		}
    48  		if matches[2] == "*" {
    49  			major := int64(-1)
    50  			dPermissions.Major = &major
    51  		} else {
    52  			major, err := strconv.ParseInt(matches[2], 10, 64)
    53  			if err != nil {
    54  				return nil, fmt.Errorf("invalid major value in device cgroup rule format: '%s'", deviceCgroupRule)
    55  			}
    56  			dPermissions.Major = &major
    57  		}
    58  		if matches[3] == "*" {
    59  			minor := int64(-1)
    60  			dPermissions.Minor = &minor
    61  		} else {
    62  			minor, err := strconv.ParseInt(matches[3], 10, 64)
    63  			if err != nil {
    64  				return nil, fmt.Errorf("invalid minor value in device cgroup rule format: '%s'", deviceCgroupRule)
    65  			}
    66  			dPermissions.Minor = &minor
    67  		}
    68  		devPermissions = append(devPermissions, dPermissions)
    69  	}
    70  	return devPermissions, nil
    71  }