Merge pull request #115 from ddddddO/save_pcap

Save pcap

.gitignore

@@ -0,0 +1 @@
+packemon_pcap/

README.md

@@ -35,7 +35,7 @@ Packemon's Monitor allows user to select each packet by pressing `Enter` key. Th
 > Incidentally, dropping RST packets is done by running [the eBPF program](./egress_control/).
 > The background note incorporating the eBPF is the POST of X around [here](https://x.com/ddddddOpppppp/status/1798715056513056881). 
 
-- [x] Send generated packets to any network interfaces.
+- Send generated packets to any network interfaces.
   - You can specify network interface with `--interface` flag. Default is `eth0`.
 
 - The following types of packets are covered.
@@ -70,9 +70,11 @@ Packemon's Monitor allows user to select each packet by pressing `Enter` key. Th
 
 ### Packet Monitor
 
-- [x] Monitor any network interfaces.
+- Monitor any network interfaces.
   - You can specify network interface with `--interface` flag. Default is `eth0`.
 
+- Specified packets can be saved to pcap file.
+
 - The following types of packets are covered.
   - [x] Ethernet
   - [x] ARP

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/gdamore/encoding v1.0.1 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
+	github.com/gopacket/gopacket v1.3.1 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect

go.sum

@@ -16,6 +16,8 @@ github.com/go-quicktest/qt v1.101.0 h1:O1K29Txy5P2OK0dGo59b7b0LR6wKfIhttaAhHUyn7
 github.com/go-quicktest/qt v1.101.0/go.mod h1:14Bz/f7NwaXPtdYEgzsx46kqSxVwTbzVZsDC26tQJow=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/gopacket/gopacket v1.3.1 h1:ZppWyLrOJNZPe5XkdjLbtuTkfQoxQ0xyMJzQCqtqaPU=
+github.com/gopacket/gopacket v1.3.1/go.mod h1:3I13qcqSpB2R9fFQg866OOgzylYkZxLTmkvcXhvf6qg=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=

internal/tui/tui.go

@@ -92,5 +92,5 @@ func (t *tui) Monitor(passiveCh <-chan *packemon.Passive, columns string) error
 	})
 
 	go t.updateTable(passiveCh, columns)
-	return t.app.SetRoot(t.pages, true).Run()
+	return t.app.SetRoot(t.pages, true).EnableMouse(true).Run()
 }

internal/tui/view.go

@@ -2,11 +2,17 @@ package tui
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 	"runtime/debug"
 	"strings"
+	"time"
 
 	"github.com/ddddddO/packemon"
 	"github.com/gdamore/tcell/v2"
+	"github.com/gopacket/gopacket"
+	"github.com/gopacket/gopacket/layers"
+	"github.com/gopacket/gopacket/pcapgo"
 	"github.com/rivo/tview"
 )
 
@@ -30,22 +36,35 @@ func (t *tui) updateView(passive *packemon.Passive) {
 			t.grid.Clear()
 		})
 
-		rows := make([]int, len(viewers))
-		columns := make([]int, len(viewers))
+		t.grid.RemoveItem(t.grid) // ほんと？
+
+		// +1 分は、PCAP保存領域用(savingPCAPView)
+		rows := make([]int, len(viewers)+1)
+		columns := make([]int, len(viewers)+1)
+		rows[0] = 5
+		columns[0] = 30
 		for i := range viewers {
 			rows[i] = viewers[i].rows()
 			columns[i] = viewers[i].columns()
 		}
-		t.grid.RemoveItem(t.grid) // ほんと？
-		t.grid.SetRows(rows...).SetColumns(columns...).SetBorders(false)
+
+		// SetRows しなくなったので、各テーブルの rows メソッドいらないかも
+		// t.grid.SetRows(rows...).SetColumns(columns...).SetBorders(false)
+		t.grid.SetColumns(columns...).SetBorders(false)
+
 		for i := range viewers {
 			t.grid.AddItem(viewers[i].viewTable(), i, 0, 1, 3, 0, 0, false) // focus=true にするとスクロールしない
 		}
+		savingPCAPView := t.savingPCAPView(passive)
+		row := len(viewers)
+		t.grid.AddItem(savingPCAPView, row, 0, 1, 3, 0, 0, false)
+
 		t.grid.SetInputCapture(
 			func(event *tcell.EventKey) *tcell.EventKey {
 				if event.Key() == tcell.KeyEscape {
 					t.grid.Clear()
 					t.pages.SwitchToPage("history")
+					t.app.SetFocus(t.pages)
 				}
 				return event
 			})
@@ -130,6 +149,61 @@ func passiveToViewers(passive *packemon.Passive) []Viewer {
 	return viewers
 }
 
+func (t *tui) savingPCAPView(p *packemon.Passive) *tview.Form {
+	now := time.Now()
+	fpath := fmt.Sprintf("./packemon_pcap/%s.pcap", now.Format("20060102150405"))
+	form := tview.NewForm().
+		AddInputField("File Name", fpath, 40, func(textToCheck string, lastChar rune) bool {
+			if len(textToCheck) < 40 {
+				fpath = textToCheck
+				return true
+			} else if len(textToCheck) > 40 {
+				return false
+			}
+			fpath = textToCheck
+			return true
+		}, nil).
+		AddButton("Save", func() {
+			if p.EthernetFrame == nil {
+				t.addErrPageForMonitor(fmt.Errorf("Empty ethernet frame..."))
+				return
+			}
+
+			dir := filepath.Dir(fpath)
+			if err := os.MkdirAll(dir, 0755); err != nil {
+				t.addErrPageForMonitor(err)
+				return
+			}
+
+			f, err := os.Create(fpath)
+			if err != nil {
+				t.addErrPageForMonitor(err)
+				return
+			}
+			defer f.Close()
+
+			pcapw := pcapgo.NewWriter(f)
+			if err := pcapw.WriteFileHeader(1500, layers.LinkTypeEthernet); err != nil {
+				t.addErrPageForMonitor(err)
+				return
+			}
+			ci := gopacket.CaptureInfo{
+				Timestamp:     now,
+				CaptureLength: 1500,
+				Length:        1500,
+				// InterfaceIndex: intf.Index, // 必須ではなさそう
+			}
+			if err := pcapw.WritePacket(ci, p.EthernetFrame.Bytes()); err != nil {
+				t.addErrPageForMonitor(err)
+				return
+			}
+		})
+	form.SetBorder(true)
+	form.Box = tview.NewBox().SetBorder(true).SetTitle(" Save PACP ").SetTitleAlign(tview.AlignLeft).SetBorderPadding(1, 1, 1, 1)
+
+	return form
+}
+
 func tableCellTitle(title string) *tview.TableCell {
 	return tview.NewTableCell(padding(title))
 }