inspektor-gadget

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// Copyright 2022-2023 The Inspektor Gadget authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package tracer
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import (
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	"errors"
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	"strconv"
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	"strings"
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	gadgetregistry "github.com/inspektor-gadget/inspektor-gadget/pkg/gadget-registry"
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	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets"
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	"github.com/inspektor-gadget/inspektor-gadget/pkg/gadgets/trace/signal/types"
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	"github.com/inspektor-gadget/inspektor-gadget/pkg/params"
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	"github.com/inspektor-gadget/inspektor-gadget/pkg/parser"
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)
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type GadgetDesc struct{}
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func (g *GadgetDesc) Name() string {
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	return "signal"
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}
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func (g *GadgetDesc) Category() string {
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	return gadgets.CategoryTrace
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}
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func (g *GadgetDesc) Type() gadgets.GadgetType {
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	return gadgets.TypeTrace
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}
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func (g *GadgetDesc) Description() string {
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	return "Trace signals received by processes"
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}
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const (
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	ParamPID          = "pid"
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	ParamTargetSignal = "signal"
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	ParamFailedOnly   = "failed-only"
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	ParamKillOnly     = "kill-only"
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)
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func (g *GadgetDesc) ParamDescs() params.ParamDescs {
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	return params.ParamDescs{
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		{
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			Key:          ParamPID,
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			DefaultValue: "0",
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			Description:  "Show only signal sent by this particular PID",
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			TypeHint:     params.TypeInt32,
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		},
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		{
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			Key:         ParamTargetSignal,
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			Description: `Trace only this signal (it can be an int like 9 or string beginning with "SIG" like "SIGKILL")`,
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			Validator:   validateSignal,
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		},
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		{
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			Key:          ParamFailedOnly,
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			Alias:        "f",
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			DefaultValue: "false",
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			Description:  "Show only events where the syscall sending a signal failed",
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			TypeHint:     params.TypeBool,
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		},
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		{
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			Key:          ParamKillOnly,
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			Alias:        "k",
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			DefaultValue: "false",
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			Description:  "Show only events issued by kill syscall",
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			TypeHint:     params.TypeBool,
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		},
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	}
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}
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func (g *GadgetDesc) Parser() parser.Parser {
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	return parser.NewParser[types.Event](types.GetColumns())
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}
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func (g *GadgetDesc) EventPrototype() any {
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	return &types.Event{}
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}
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func init() {
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	gadgetregistry.Register(&GadgetDesc{})
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}
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// validateSignal checks whether the signal argument is empty, contains a number, or starts with "SIG".
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// We cannot perform the same check signalStringToInt does, because that is not cross-platform compatible.
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func validateSignal(signal string) error {
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	if signal == "" {
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		return nil
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	}
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	if strings.HasPrefix(signal, "SIG") {
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		return nil
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	}
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	if _, err := strconv.Atoi(signal); err == nil {
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		return nil
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	}
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	return errors.New("expected a signal number or a signal name starting with 'SIG'")
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}
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