From: Kirill A. Korinsky <kirill@korins.ky>
Subject: [maintainer] net/tcpflow: fix loopback
To: OpenBSD ports <ports@openbsd.org>
Cc: Klemens Nanni <kn@openbsd.org>
Date: Thu, 19 Sep 2024 01:02:44 +0200

ports@,

Here's a diff for net/tcpflow that fixes listening on a loopback interface,
I hope that I'm not too late to fix this in 7.6

It was backported to upstream as well as:
https://github.com/simsong/tcpflow/pull/265

Tested on -current/amd64.

The diff:

Index: Makefile
===================================================================
RCS file: /cvs/ports/net/tcpflow/Makefile,v
retrieving revision 1.31
diff -u -p -r1.31 Makefile
--- Makefile	10 Jun 2024 18:51:59 -0000	1.31
+++ Makefile	18 Sep 2024 22:58:29 -0000
@@ -3,7 +3,7 @@ COMMENT=		tool for capturing data from T
 V=			1.6.1
 DISTNAME=		tcpflow-${V}
 CATEGORIES=		net
-REVISION=		1
+REVISION=		2
 
 SITES=			https://github.com/simsong/tcpflow/releases/download/tcpflow-${V}/
 
Index: patches/patch-src_datalink_cpp
===================================================================
RCS file: /cvs/ports/net/tcpflow/patches/patch-src_datalink_cpp,v
retrieving revision 1.1
diff -u -p -r1.1 patch-src_datalink_cpp
--- patches/patch-src_datalink_cpp	6 Jun 2024 14:04:36 -0000	1.1
+++ patches/patch-src_datalink_cpp	18 Sep 2024 22:58:29 -0000
@@ -1,9 +1,32 @@
 Index: src/datalink.cpp
 --- src/datalink.cpp.orig
 +++ src/datalink.cpp
-@@ -71,6 +71,29 @@ void dl_null(u_char *user, const struct pcap_pkthdr *h
+@@ -70,7 +70,52 @@ void dl_null(u_char *user, const struct pcap_pkthdr *h
+ }
  #pragma GCC diagnostic warning "-Wcast-align"
  
++#define	LOOP_HDRLEN 4
++
++void dl_loop(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
++{
++    u_int caplen = h->caplen;
++    u_int length = h->len;
++
++    if (length != caplen) {
++	DEBUG(6) ("warning: only captured %d bytes of %d byte null frame",
++		  caplen, length);
++    }
++
++    if (caplen < NULL_HDRLEN) {
++	DEBUG(6) ("warning: received incomplete null frame");
++	return;
++    }
++
++    struct timeval tv;
++    be13::packet_info pi(DLT_LOOP,h,p,tvshift(tv,h->ts),p+LOOP_HDRLEN,caplen - LOOP_HDRLEN);
++    be13::plugin::process_packet(pi);
++}
++
  static uint64_t counter=0;
 +
 +#define	PPP_ETHER_HDRLEN 8
@@ -31,11 +54,19 @@ Index: src/datalink.cpp
  /* DLT_RAW: just a raw IP packet, no encapsulation or link-layer
   * headers.  Used for PPP connections under some OSs including Linux
   * and IRIX. */
-@@ -278,14 +301,18 @@ dlt_handler_t handlers[] = {
-     { dl_raw,     101 },
+@@ -269,7 +314,8 @@ void dl_linux_sll(u_char *user, const struct pcap_pkth
+ 
+ /* List of callbacks for each data link type */
+ dlt_handler_t handlers[] = {
+-    { dl_null,	   DLT_NULL },
++    { dl_null,     DLT_NULL },
++    { dl_loop,     DLT_LOOP },
+ /* Some systems define DLT_RAW as 12, some as 14, and some as 101.
+  * So it is hard-coded here.
+  */
+@@ -279,13 +325,16 @@ dlt_handler_t handlers[] = {
      { dl_ethernet, DLT_EN10MB },
      { dl_ethernet, DLT_IEEE802 },
-+    { dl_null,          DLT_LOOP },
      { dl_ppp,           DLT_PPP },
 +    { dl_ppp_ether,     DLT_PPP_ETHER },
  #ifdef DLT_LINUX_SLL


-- 
wbr, Kirill