github.com/google/osv-scalibr@v0.4.1/extractor/filesystem/embeddedfs/ova/ova.go (about)

     1  // Copyright 2025 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package ova provides an extractor for extracting software inventories from OVA archives
    16  package ova
    17  
    18  import (
    19  	"context"
    20  	"errors"
    21  	"fmt"
    22  	"strings"
    23  	"sync"
    24  
    25  	cpb "github.com/google/osv-scalibr/binary/proto/config_go_proto"
    26  	"github.com/google/osv-scalibr/extractor/filesystem"
    27  	"github.com/google/osv-scalibr/extractor/filesystem/embeddedfs/common"
    28  	scalibrfs "github.com/google/osv-scalibr/fs"
    29  	"github.com/google/osv-scalibr/inventory"
    30  	"github.com/google/osv-scalibr/plugin"
    31  )
    32  
    33  const (
    34  	// Name is the unique identifier for the ova extractor.
    35  	Name = "embeddedfs/ova"
    36  )
    37  
    38  // Extractor implements the filesystem.Extractor interface for ova.
    39  type Extractor struct {
    40  	// maxFileSizeBytes is the maximum size of an archive file that can be traversed.
    41  	// If this limit is greater than zero and a file is encountered that is larger
    42  	// than this limit, the file is ignored.
    43  	maxFileSizeBytes int64
    44  }
    45  
    46  // New returns a new ova extractor.
    47  func New(cfg *cpb.PluginConfig) filesystem.Extractor {
    48  	maxSize := cfg.MaxFileSizeBytes
    49  	specific := plugin.FindConfig(cfg, func(c *cpb.PluginSpecificConfig) *cpb.OVAConfig { return c.GetOva() })
    50  	if specific.GetMaxFileSizeBytes() > 0 {
    51  		maxSize = specific.GetMaxFileSizeBytes()
    52  	}
    53  	return &Extractor{maxFileSizeBytes: maxSize}
    54  }
    55  
    56  // Name returns the name of the extractor.
    57  func (e *Extractor) Name() string {
    58  	return Name
    59  }
    60  
    61  // Version returns the version of the extractor.
    62  func (e *Extractor) Version() int {
    63  	return 0
    64  }
    65  
    66  // Requirements returns the requirements for the extractor.
    67  func (e *Extractor) Requirements() *plugin.Capabilities {
    68  	return &plugin.Capabilities{}
    69  }
    70  
    71  // FileRequired checks if the file is a .ova file based on its extension.
    72  func (e *Extractor) FileRequired(api filesystem.FileAPI) bool {
    73  	path := api.Path()
    74  	if !strings.HasSuffix(strings.ToLower(path), ".ova") {
    75  		return false
    76  	}
    77  
    78  	fileinfo, err := api.Stat()
    79  	if err != nil {
    80  		return false
    81  	}
    82  
    83  	if e.maxFileSizeBytes > 0 && fileinfo.Size() > e.maxFileSizeBytes {
    84  		return false
    85  	}
    86  
    87  	return true
    88  }
    89  
    90  // Extract returns an Inventory with embedded filesystems which contains a mount function for the filesystem in the .ova file.
    91  func (e *Extractor) Extract(ctx context.Context, input *filesystem.ScanInput) (inventory.Inventory, error) {
    92  	// Check wether input.Reader is nil or not.
    93  	// This check is crucial because tar.NewReader doesn't validate the input,
    94  	// it simply wraps it around tar.Reader.
    95  	if input.Reader == nil {
    96  		return inventory.Inventory{}, errors.New("input.Reader is nil")
    97  	}
    98  
    99  	tempDir, err := common.TARToTempDir(input.Reader)
   100  	if err != nil {
   101  		return inventory.Inventory{}, fmt.Errorf("common.TARToTempDir(%q): %w", input.Path, err)
   102  	}
   103  
   104  	var refCount int32 = 1
   105  	var refMu sync.Mutex
   106  	getEmbeddedFS := func(ctx context.Context) (scalibrfs.FS, error) {
   107  		return &common.EmbeddedDirFS{
   108  			FS:       scalibrfs.DirFS(tempDir),
   109  			File:     nil,
   110  			TmpPaths: []string{tempDir},
   111  			RefCount: &refCount,
   112  			RefMu:    &refMu,
   113  		}, nil
   114  	}
   115  	var inv inventory.Inventory
   116  	inv.EmbeddedFSs = append(inv.EmbeddedFSs, &inventory.EmbeddedFS{
   117  		Path:          input.Path,
   118  		GetEmbeddedFS: getEmbeddedFS,
   119  	})
   120  	return inv, nil
   121  }