github.com/noqcks/syft@v0.0.0-20230920222752-a9e2c4e288e5/syft/pkg/cataloger/kernel/parse_linux_kernel_module_file.go (about)

     1  package kernel
     2  
     3  import (
     4  	"debug/elf"
     5  	"fmt"
     6  	"strings"
     7  
     8  	"github.com/anchore/syft/syft/artifact"
     9  	"github.com/anchore/syft/syft/file"
    10  	"github.com/anchore/syft/syft/pkg"
    11  	"github.com/anchore/syft/syft/pkg/cataloger/generic"
    12  	"github.com/anchore/syft/syft/pkg/cataloger/internal/unionreader"
    13  )
    14  
    15  const modinfoName = ".modinfo"
    16  
    17  func parseLinuxKernelModuleFile(_ file.Resolver, _ *generic.Environment, reader file.LocationReadCloser) ([]pkg.Package, []artifact.Relationship, error) {
    18  	unionReader, err := unionreader.GetUnionReader(reader)
    19  	if err != nil {
    20  		return nil, nil, fmt.Errorf("unable to get union reader for file: %w", err)
    21  	}
    22  	metadata, err := parseLinuxKernelModuleMetadata(unionReader)
    23  	if err != nil {
    24  		return nil, nil, fmt.Errorf("unable to parse kernel module metadata: %w", err)
    25  	}
    26  	if metadata == nil || metadata.KernelVersion == "" {
    27  		return nil, nil, nil
    28  	}
    29  
    30  	metadata.Path = reader.Location.RealPath
    31  
    32  	return []pkg.Package{
    33  		newLinuxKernelModulePackage(
    34  			*metadata,
    35  			reader.Location,
    36  		),
    37  	}, nil, nil
    38  }
    39  
    40  func parseLinuxKernelModuleMetadata(r unionreader.UnionReader) (p *pkg.LinuxKernelModuleMetadata, err error) {
    41  	// filename:       /lib/modules/5.15.0-1031-aws/kernel/zfs/zzstd.ko
    42  	// version:        1.4.5a
    43  	// license:        Dual BSD/GPL
    44  	// description:    ZSTD Compression for ZFS
    45  	// srcversion:     F1F818A6E016499AB7F826E
    46  	// depends:        spl
    47  	// retpoline:      Y
    48  	// name:           zzstd
    49  	// vermagic:       5.15.0-1031-aws SMP mod_unload modversions
    50  	// sig_id:         PKCS#7
    51  	// signer:         Build time autogenerated kernel key
    52  	// sig_key:        49:A9:55:87:90:5B:33:41:AF:C0:A7:BE:2A:71:6C:D2:CA:34:E0:AE
    53  	// sig_hashalgo:   sha512
    54  	//
    55  	// OR
    56  	//
    57  	// filename:       /home/ubuntu/eve/rootfs/lib/modules/5.10.121-linuxkit/kernel/drivers/net/wireless/realtek/rtl8821cu/8821cu.ko
    58  	// version:        v5.4.1_28754.20180921_COEX20180712-3232
    59  	// author:         Realtek Semiconductor Corp.
    60  	// description:    Realtek Wireless Lan Driver
    61  	// license:        GPL
    62  	// srcversion:     960CCC648A0E0369171A2C9
    63  	// depends:        cfg80211
    64  	// retpoline:      Y
    65  	// name:           8821cu
    66  	// vermagic:       5.10.121-linuxkit SMP mod_unload
    67  	p = &pkg.LinuxKernelModuleMetadata{
    68  		Parameters: make(map[string]pkg.LinuxKernelModuleParameter),
    69  	}
    70  	f, err := elf.NewFile(r)
    71  	if err != nil {
    72  		return nil, err
    73  	}
    74  	defer f.Close()
    75  	modinfo := f.Section(modinfoName)
    76  	if modinfo == nil {
    77  		return nil, fmt.Errorf("no section %s", modinfoName)
    78  	}
    79  	b, err := modinfo.Data()
    80  	if err != nil {
    81  		return nil, fmt.Errorf("error reading secion %s: %w", modinfoName, err)
    82  	}
    83  	var (
    84  		entry []byte
    85  	)
    86  	for _, b2 := range b {
    87  		if b2 == 0 {
    88  			if err := addLinuxKernelModuleEntry(p, entry); err != nil {
    89  				return nil, fmt.Errorf("error parsing entry %s: %w", string(entry), err)
    90  			}
    91  			entry = []byte{}
    92  			continue
    93  		}
    94  		entry = append(entry, b2)
    95  	}
    96  	if err := addLinuxKernelModuleEntry(p, entry); err != nil {
    97  		return nil, fmt.Errorf("error parsing entry %s: %w", string(entry), err)
    98  	}
    99  
   100  	return p, nil
   101  }
   102  
   103  func addLinuxKernelModuleEntry(k *pkg.LinuxKernelModuleMetadata, entry []byte) error {
   104  	if len(entry) == 0 {
   105  		return nil
   106  	}
   107  	var key, value string
   108  	parts := strings.SplitN(string(entry), "=", 2)
   109  	if len(parts) > 0 {
   110  		key = parts[0]
   111  	}
   112  	if len(parts) > 1 {
   113  		value = parts[1]
   114  	}
   115  
   116  	switch key {
   117  	case "version":
   118  		k.Version = value
   119  	case "license":
   120  		k.License = value
   121  	case "author":
   122  		k.Author = value
   123  	case "name":
   124  		k.Name = value
   125  	case "vermagic":
   126  		k.VersionMagic = value
   127  		fields := strings.Fields(value)
   128  		if len(fields) > 0 {
   129  			k.KernelVersion = fields[0]
   130  		}
   131  	case "srcversion":
   132  		k.SourceVersion = value
   133  	case "description":
   134  		k.Description = value
   135  	case "parm":
   136  		parts := strings.SplitN(value, ":", 2)
   137  		if len(parts) != 2 {
   138  			return fmt.Errorf("invalid parm entry: %s", value)
   139  		}
   140  		if m, ok := k.Parameters[parts[0]]; !ok {
   141  			k.Parameters[parts[0]] = pkg.LinuxKernelModuleParameter{Description: parts[1]}
   142  		} else {
   143  			m.Description = parts[1]
   144  		}
   145  	case "parmtype":
   146  		parts := strings.SplitN(value, ":", 2)
   147  		if len(parts) != 2 {
   148  			return fmt.Errorf("invalid parmtype entry: %s", value)
   149  		}
   150  		if m, ok := k.Parameters[parts[0]]; !ok {
   151  			k.Parameters[parts[0]] = pkg.LinuxKernelModuleParameter{Type: parts[1]}
   152  		} else {
   153  			m.Type = parts[1]
   154  		}
   155  	}
   156  	return nil
   157  }