github.com/inspektor-gadget/inspektor-gadget@v0.28.1/pkg/gadget-collection/gadgets/trace/mount/gadget.go (about)

     1  // Copyright 2022 The Inspektor Gadget authors
     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 mountsnoop
    16  
    17  import (
    18  	"encoding/json"
    19  	"fmt"
    20  
    21  	log "github.com/sirupsen/logrus"
    22  
    23  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadget-collection/gadgets"
    24  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadget-collection/gadgets/trace"
    25  
    26  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/trace/mount/tracer"
    27  
    28  	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/trace/mount/types"
    29  
    30  	gadgetv1alpha1 "github.com/inspektor-gadget/inspektor-gadget/pkg/apis/gadget/v1alpha1"
    31  )
    32  
    33  type Trace struct {
    34  	helpers gadgets.GadgetHelpers
    35  
    36  	started bool
    37  	tracer  trace.Tracer
    38  }
    39  
    40  type TraceFactory struct {
    41  	gadgets.BaseFactory
    42  }
    43  
    44  func NewFactory() gadgets.TraceFactory {
    45  	return &TraceFactory{
    46  		BaseFactory: gadgets.BaseFactory{DeleteTrace: deleteTrace},
    47  	}
    48  }
    49  
    50  func (f *TraceFactory) Description() string {
    51  	return `mountsnoop traces mount and umount syscalls`
    52  }
    53  
    54  func (f *TraceFactory) OutputModesSupported() map[gadgetv1alpha1.TraceOutputMode]struct{} {
    55  	return map[gadgetv1alpha1.TraceOutputMode]struct{}{
    56  		gadgetv1alpha1.TraceOutputModeStream: {},
    57  	}
    58  }
    59  
    60  func deleteTrace(name string, t interface{}) {
    61  	trace := t.(*Trace)
    62  	if trace.tracer != nil {
    63  		trace.tracer.Stop()
    64  	}
    65  }
    66  
    67  func (f *TraceFactory) Operations() map[gadgetv1alpha1.Operation]gadgets.TraceOperation {
    68  	n := func() interface{} {
    69  		return &Trace{
    70  			helpers: f.Helpers,
    71  		}
    72  	}
    73  
    74  	return map[gadgetv1alpha1.Operation]gadgets.TraceOperation{
    75  		gadgetv1alpha1.OperationStart: {
    76  			Doc: "Start mountsnoop gadget",
    77  			Operation: func(name string, trace *gadgetv1alpha1.Trace) {
    78  				f.LookupOrCreate(name, n).(*Trace).Start(trace)
    79  			},
    80  		},
    81  		gadgetv1alpha1.OperationStop: {
    82  			Doc: "Stop mountsnoop gadget",
    83  			Operation: func(name string, trace *gadgetv1alpha1.Trace) {
    84  				f.LookupOrCreate(name, n).(*Trace).Stop(trace)
    85  			},
    86  		},
    87  	}
    88  }
    89  
    90  func (t *Trace) Start(trace *gadgetv1alpha1.Trace) {
    91  	if t.started {
    92  		trace.Status.State = gadgetv1alpha1.TraceStateStarted
    93  		return
    94  	}
    95  
    96  	traceName := gadgets.TraceName(trace.ObjectMeta.Namespace, trace.ObjectMeta.Name)
    97  
    98  	eventCallback := func(event *types.Event) {
    99  		r, err := json.Marshal(event)
   100  		if err != nil {
   101  			log.Warnf("Gadget %s: error marshaling event: %s", trace.Spec.Gadget, err)
   102  			return
   103  		}
   104  		t.helpers.PublishEvent(traceName, string(r))
   105  	}
   106  
   107  	var err error
   108  
   109  	mountNsMap, err := t.helpers.TracerMountNsMap(traceName)
   110  	if err != nil {
   111  		trace.Status.OperationError = fmt.Sprintf("failed to find tracer's mount ns map: %s", err)
   112  		return
   113  	}
   114  	config := &tracer.Config{
   115  		MountnsMap: mountNsMap,
   116  	}
   117  	t.tracer, err = tracer.NewTracer(config, t.helpers, eventCallback)
   118  	if err != nil {
   119  		trace.Status.OperationError = fmt.Sprintf("failed to create tracer: %s", err)
   120  		return
   121  	}
   122  
   123  	t.started = true
   124  
   125  	trace.Status.State = gadgetv1alpha1.TraceStateStarted
   126  }
   127  
   128  func (t *Trace) Stop(trace *gadgetv1alpha1.Trace) {
   129  	if !t.started {
   130  		trace.Status.OperationError = "Not started"
   131  		return
   132  	}
   133  
   134  	t.tracer.Stop()
   135  	t.tracer = nil
   136  	t.started = false
   137  
   138  	trace.Status.State = gadgetv1alpha1.TraceStateStopped
   139  }