soypat/lneto
1
0
Fork 0
mirror of https://github.com/soypat/lneto.git synced 2026-09-10 00:29:34 +00:00
Code Issues Packages Projects Releases 1 Wiki Activity

heap: remove heap alloc in pcap of HTTP content type; more debugging logs

Browse Source
This commit is contained in:
Patricio Whittingslow
2026-02-28 17:46:08 -03:00
parent 4f7635b216
commit f6e7801d8c
5 changed files with 40 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files
internet/pcap/capture.go
+17 -14
View File
@@ -2,12 +2,12 @@ package pcap
//go:generate stringer -type=FieldClass -linecomment -output stringers.go .
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"log/slog"
"math"
"strings"
"unsafe"
"github.com/soypat/lneto"
"github.com/soypat/lneto/arp"
@@ -553,21 +553,21 @@ func (pc *PacketBreakdown) CaptureDHCPv4(dst []Frame, pkt []byte, bitOffset int)
// based on the Content-Type header, falling back to byte inspection when Content-Type is absent.
func httpBodyClass(contentType, body []byte) FieldClass {
if len(contentType) > 0 {
// Use unsafe string conversion to avoid []byte("literal") heap allocations in TinyGo.
ct := unsafe.String(&contentType[0], len(contentType))
// Strip parameters (e.g. "; charset=utf-8") for media type matching.
mediaType := contentType
if i := bytes.IndexByte(contentType, ';'); i >= 0 {
mediaType = contentType[:i]
if i := strings.IndexByte(ct, ';'); i >= 0 {
ct = strings.TrimSpace(ct[:i])
}
mediaType = bytes.TrimSpace(mediaType)
switch {
case bytes.HasPrefix(mediaType, []byte("text/")):
case strings.HasPrefix(ct, "text/"):
return FieldClassText
case internal.BytesEqual(mediaType, []byte("application/json")),
internal.BytesEqual(mediaType, []byte("application/javascript")),
internal.BytesEqual(mediaType, []byte("application/xml")):
case ct == "application/json",
ct == "application/javascript",
ct == "application/xml":
return FieldClassText
case bytes.HasSuffix(mediaType, []byte("+json")),
bytes.HasSuffix(mediaType, []byte("+xml")):
case strings.HasSuffix(ct, "+json"),
strings.HasSuffix(ct, "+xml"):
return FieldClassText
}
return FieldClassPayload
@@ -603,8 +603,11 @@ func (pc *PacketBreakdown) CaptureHTTP(dst []Frame, pkt []byte, bitOffset int) (
debuglog("pcap:http:parsed")
hdrLen := pc.hdr.BufferParsed()
body, _ := pc.hdr.Body()
debuglog("pcap:http:body")
bodyClass := httpBodyClass(pc.hdr.Get("Content-Type"), body)
debuglog("pcap:http:bodyclass")
finfo := reclaimFrame(&dst, httpProtocol, bitOffset, nil)
debuglog("pcap:http:reclaim")
finfo.Fields = append(finfo.Fields,
FrameField{
Name: "HTTP Header",
@@ -1351,10 +1354,10 @@ func reclaimRemainingFrame(dst *[]Frame, proto string, class FieldClass, pktBitO
})
}
const enableDebug = false
const enableDebug = internal.HeapAllocDebugging
func debuglog(msg string) {
if enableDebug {
internal.LogAttrs(nil, slog.LevelDebug, msg)
internal.LogAllocs(msg)
}
}