Start adding convenience

gapstring/gapstring.go

@@ -1,9 +1,9 @@
 package gapstring
 
 import (
+	"bytes"
 	"fmt"
 	"encoding/binary"
-	"encoding/hex"
 	"strings"
 	"unicode/utf16"
 )
@@ -194,8 +194,25 @@ func (g GapString) String(fill string) string {
 	return string(g.Bytes([]byte(fill)...))
 }
 
-func (g GapString) HexString(fill ...byte) string {
+func (g GapString) HexString() string {
-	return hex.EncodeToString(g.Bytes(fill...))
+	out := new(strings.Builder)
+	glen := g.Length()
+	for i := 0; i < glen; i += 1 {
+		c := g.ValueAt(i)
+		if c == -1 {
+			out.WriteString("--")
+		} else {
+			// There's probably a faster way to do this. Do we care?
+			fmt.Fprintf(out, "%02x", c)
+		}
+		if i + 1 < glen {
+			out.WriteRune(' ')
+			if i % 8 == 7 {
+				out.WriteRune(' ')
+			}
+		}
+	}
+	return out.String()
 }
 
 var fluffych = []rune{
@@ -216,70 +233,47 @@ var fluffych = []rune{
 	'α', 'ß', 'Γ', 'π', 'Σ', 'σ', 'µ', 'τ', 'Φ', 'Θ', 'Ω', 'δ', '∞', 'φ', 'ε', '∩',
 	'≡', '±', '≥', '≤', '⌠', '⌡', '÷', '≈', '°', '∀', '∃', '√', 'ⁿ', '²', '■', '¤',
 }
+func (g GapString) Runes() string {
+	out := new(strings.Builder)
+	glen := g.Length()
+	for i := 0; i < glen; i += 1 {
+		c := g.ValueAt(i)
+		if c == -1 {
+			out.WriteRune('<27>')
+		} else {
+			out.WriteRune(fluffych[c])
+		}
+	}
+	return out.String()
+}
+
 func (g GapString) Hexdump() string {
 	out := new(strings.Builder)
 	skipping := false
 	glen := g.Length()
 	pos := 0
+	prev := []byte{}
 	for ; pos < glen; {
 		// Check for repeats
-		repeated := true
+		end := pos + 16
-		if (pos > 0) {
+		if end > glen {
-			for i := 0; (i < 16) && (pos+i < glen); i += 1 {
+			end = glen
-				if g.ValueAt(pos+i) != g.ValueAt(pos+i-16) {
-					repeated = false
-					break
 		}
-			}
+		cur := g.Slice(pos, end)
-			if repeated {
+		curBytes := cur.Bytes()
+		if 0 == bytes.Compare(prev, curBytes) {
 			if ! skipping {
 				fmt.Fprintln(out, "*")
 				skipping = true
 			}
-				pos += 16
 			continue
-			} else {
-				skipping = false
-			}
 		}
 
-		// Output offset
 		fmt.Fprintf(out, "%08x  ", pos)
+		fmt.Fprintf(out, "%-50s", cur.HexString())
+		fmt.Fprintln(out, cur.Runes())
 
-		// Output octet values
+		pos += cur.Length()
-		for i := 0; i < 16; i += 1 {
-			if pos+i < glen {
-				c := g.ValueAt(pos+i)
-				if c == -1 {
-					fmt.Fprintf(out, "-- ")
-				} else {
-					fmt.Fprintf(out, "%02x ", c)
-				}
-			} else {
-				fmt.Fprintf(out, "   ")
-			}
-			if i == 7 {
-				fmt.Fprintf(out, " ")
-			}
-		}
-		
-		fmt.Fprintf(out, " ")
-		
-		
-		// Output octet glyphs
-		for i := 0; (i < 16) && (pos < glen); {
-			c := g.ValueAt(pos)
-			if c == -1 {
-				fmt.Fprintf(out, "<22>")
-			} else {
-				fmt.Fprintf(out, "%c", fluffych[c])
-			}
-			i += 1
-			pos += 1
-		}
-		
-		// Output newline
-		fmt.Fprintln(out, "")
 	}
 	fmt.Fprintf(out, "%08x\n", pos)
 	

packet.go

@@ -1,8 +1,8 @@
 package netshovel
 
 import (
+	"encoding/hex"
 	"fmt"
-	"sort"
 	"strings"
 	"time"
 	"github.com/dirtbags/netshovel/gapstring"
@@ -10,51 +10,72 @@ import (
 
 type PacketFactory func()Packet
 
+type Field struct {
+	key, value string
+}
+
 type Packet struct {
 	Name string
 	Opcode int
 	Description string
 	When time.Time
 	Payload gapstring.GapString
-	Fields map[string]string
+	Fields []Field
 }
 
 var never = time.Unix(0, 0)
 
 func NewPacket() Packet {
 	return Packet{
-		Name: "Generic",
 		Opcode: -1,
 		Description: "Undefined",
 		When: never,
 		Payload: gapstring.GapString{},
-		Fields: map[string]string{},
+		Fields: []Field{},
 	}
 }
 
 func (pkt *Packet) Describe() string {
 	out := new(strings.Builder)
 
-	fmt.Fprintf(out, "  %s %s %d: %s\n",
+	fmt.Fprintf(out, "  %s Opcode %d: %s\n",
 	  pkt.When.UTC().Format(time.RFC3339Nano),
-		pkt.Name,
 		pkt.Opcode,
 		pkt.Description,
 	)
-	keys := make([]string, len(pkt.Fields))
+	
-	i := 0
+	for _, f := range(pkt.Fields) {
-	for k := range(pkt.Fields) {
+		fmt.Fprintf(out, "    %s: %s\n", f.key, f.value)
-		keys[i] = k
-		i += 1
-	}
-	sort.Strings(keys)
-	for _, k := range keys {
-		fmt.Fprintf(out, "    %s: %s\n", k, pkt.Fields[k])
 	}
 	fmt.Fprint(out, pkt.Payload.Hexdump())
 	return out.String()
 }
 
+
 func (pkt *Packet) Set(key, value string) {
-	pkt.Fields[key] = value
+	pkt.Fields = append(pkt.Fields, Field{key, value})
+}
+
+func (pkt *Packet) SetString(key, value string) {
+	pkt.Set(key, fmt.Sprintf("%#v", value))
+}
+
+func (pkt *Packet) SetInt(key string, value int) {
+	pkt.Set(key, fmt.Sprintf("%d == 0x%x", value, value))
+}
+
+func (pkt *Packet) SetUint(key string, value uint) {
+	pkt.Set(key, fmt.Sprintf("%d == 0x%x", value, value))
+}
+
+func (pkt *Packet) SetUint32(key string, value uint32) {
+	pkt.Set(key, fmt.Sprintf("%d == 0x%04x", value, value))
+}
+
+func (pkt *Packet) SetBytes(key string, value []byte) {
+	pkt.Set(key, hex.EncodeToString(value))
+}
+
+func (pkt *Packet) SetGapString(key string, value gapstring.GapString) {
+	pkt.Set(key, fmt.Sprintf("%s  %s", value.HexString(), value.Runes()))
 }

stream.go

@@ -3,7 +3,8 @@ package netshovel
 import (
 	"fmt"
 	"io"
-	"log"
+	"os"
+	"net/url"
 	"strings"
 	"time"
 	"github.com/dirtbags/netshovel/gapstring"
@@ -11,9 +12,9 @@ import (
 	"github.com/google/gopacket/tcpassembly"
 )
 
-type WriteAtCloser interface {
+type NamedFile struct {
-	io.WriterAt
+	*os.File
-	io.WriteCloser
+	Name string
 }
 
 type Utterance struct {
@@ -58,10 +59,6 @@ func (stream *Stream) ReassemblyComplete() {
 }
 
 func (stream *Stream) Read(length int) (Utterance, error) {
-	if length > 0x100000 {
-		log.Fatalf("FATAL: Trying to read 0x%x octets", length)
-	}
-
 	// Special case: length=-1 means "give me the next utterance"
 	if length == -1 {
 		if stream.pending.Data.Length() > 0 {
@@ -111,3 +108,19 @@ func (stream *Stream) Describe(pkt Packet) string {
   out.WriteString(pkt.Describe())
 	return out.String()
 }
+
+func (stream *Stream) CreateFile(when time.Time, path string) (NamedFile, error) {
+  name := fmt.Sprintf(
+		"xfer/%s,%sp%s,%sp%s,%s",
+		when.UTC().Format(time.RFC3339Nano),
+		stream.Net.Src().String(), stream.Transport.Src().String(),
+    stream.Net.Dst().String(), stream.Transport.Dst().String(),
+		url.PathEscape(path),
+	)
+  f, err := os.Create(name)
+  outf := NamedFile{
+  	File: f,
+  	Name: name,
+  }
+  return outf, err
+}