From 0c418ffc4a34c864c09b8778cc0503fb60487775 Mon Sep 17 00:00:00 2001
From: Fred Klassen <fklassen@appneta.com>
Date: Thu, 29 Apr 2021 08:50:25 -0700
Subject: [PATCH] Bug #582 calculate L2 length based on exporter DLT

---
 docs/CHANGELOG                          |  2 +-
 src/tcpedit/dlt.c                       | 12 ++++++++----
 src/tcpedit/dlt.h                       |  2 +-
 src/tcpedit/edit_packet.c               |  2 +-
 src/tcpedit/plugins/dlt_en10mb/en10mb.c |  2 +-
 5 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/docs/CHANGELOG b/docs/CHANGELOG
index d7c5fd940..d4b1df78e 100644
--- a/docs/CHANGELOG
+++ b/docs/CHANGELOG
@@ -17,7 +17,7 @@
     - fix UNUSED macro declaration (#614)
     - handle malformed and unsupported packets as soft errors (#613)
     - compile failure on aarch64-linux-android (#612)
-    - tcprewrite --fixlen not working (#582)
+    - tcprewrite --fixlen not working on DLT conversion (#582)
     - fix configure --without-libdnet (#567)
     - ensure automake version is at least 1.15 (#553)
     - with multiplier option only first file can be sent and hang (#472)
diff --git a/src/tcpedit/dlt.c b/src/tcpedit/dlt.c
index 7cbc937bb..8f4bf5184 100644
--- a/src/tcpedit/dlt.c
+++ b/src/tcpedit/dlt.c
@@ -160,10 +160,14 @@ dlt2mtu(tcpedit_t *tcpedit, int dlt)
  * for it to be at all useful.
  */
 int
-layer2len(tcpedit_t *tcpedit)
+layer2len(tcpedit_t *tcpedit, u_char *packet, uint32_t caplen)
 {
-   assert(tcpedit);
-   
-   return tcpedit->dlt_ctx->l2len;
+    assert(tcpedit);
+    assert(tcpedit->dlt_ctx);
+    assert(tcpedit->dlt_ctx->encoder);
+
+    return tcpedit->dlt_ctx->encoder->plugin_l2len(tcpedit->dlt_ctx,
+                                                   packet,
+                                                   caplen);
 }
 
diff --git a/src/tcpedit/dlt.h b/src/tcpedit/dlt.h
index 088622e5f..8a592a25a 100644
--- a/src/tcpedit/dlt.h
+++ b/src/tcpedit/dlt.h
@@ -32,7 +32,7 @@
 int dlt2layer2len(tcpedit_t *tcpedit, int dlt);
 int dltrequires(tcpedit_t *tcpedit, int dlt);
 int dlt2mtu(tcpedit_t *tcpedit, int dlt);
-int layer2len(tcpedit_t *tcpedit);
+int layer2len(tcpedit_t *tcpedit, u_char *packet, uint32_t caplen);
 
 #endif /* _DLT_H_ */
 
diff --git a/src/tcpedit/edit_packet.c b/src/tcpedit/edit_packet.c
index 36818f53d..c5d7b0b4e 100644
--- a/src/tcpedit/edit_packet.c
+++ b/src/tcpedit/edit_packet.c
@@ -508,7 +508,7 @@ untrunc_packet(tcpedit_t *tcpedit, struct pcap_pkthdr *pkthdr,
             return(0);
     }
     
-    if ((l2len = layer2len(tcpedit)) < 0) {
+    if ((l2len = layer2len(tcpedit, packet, pkthdr->caplen)) < 0) {
         tcpedit_seterr(tcpedit, "Non-sensical layer 2 length: %d", l2len);
         return -1;
     }
diff --git a/src/tcpedit/plugins/dlt_en10mb/en10mb.c b/src/tcpedit/plugins/dlt_en10mb/en10mb.c
index caedbab84..db1b8d746 100644
--- a/src/tcpedit/plugins/dlt_en10mb/en10mb.c
+++ b/src/tcpedit/plugins/dlt_en10mb/en10mb.c
@@ -30,7 +30,7 @@
 #include "en10mb.h"
 
 
-static char _U_ dlt_name[] = "en10mb";
+static char dlt_name[] = "en10mb";
 static char dlt_prefix[] = "enet";
 static uint16_t dlt_value = DLT_EN10MB;