commit 6ce5d5bcbbcd8c633c8ef0969d8501c73eb5f3b4
author Dave Wallace <dwallacelf@gmail.com> Tue Jul 16 15:32:55 2024 -0400
committer Damjan Marion <dmarion@0xa5.net> Thu Jul 18 14:46:07 2024 +0000
tree ee1795dbec2aed79b7292f55a8b8dd9d2ddbb317
parent 0da0883453e7855a65fea7db85aebe69eb4d69b0

pg: fix pcap packet type when writing pcap file

- fixes incorrect pcap packet type for packet
  generator interfaces configured in ip mode.
- corrects pcap file decode for pg output files
- fixes scapy versions > 2.4.3 which now appear to
  use the packet type in the pcap file header which
  had been ignored in earlier versions

Type: fix

Change-Id: Idb1e3f8fbc7ca938fb5d2aaa72365e333c0ea2e9
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

src/vnet/pg/output.c

diff --git a/src/vnet/pg/output.c b/src/vnet/pg/output.c
index 042591a..fa1a14c 100644
--- a/src/vnet/pg/output.c
+++ b/src/vnet/pg/output.c
@@ -88,7 +88,13 @@
 	pcap_add_buffer (&pif->pcap_main, vm, bi0, ETHERNET_MAX_PACKET_BYTES);
     }
   if (pif->pcap_file_name != 0)
-    pcap_write (&pif->pcap_main);
+    {
+      pcap_packet_type_t pm_pt = pif->pcap_main.packet_type;
+      pif->pcap_main.packet_type =
+	pg_intf_mode_to_pcap_packet_type (pif->mode);
+      pcap_write (&pif->pcap_main);
+      pif->pcap_main.packet_type = pm_pt;
+    }
   if ((pif->pcap_main.flags & PCAP_MAIN_INIT_DONE)
       && pif->pcap_main.n_packets_captured >=
       pif->pcap_main.n_packets_to_capture)

src/vnet/pg/pg.h

diff --git a/src/vnet/pg/pg.h b/src/vnet/pg/pg.h
index 6d5b25b..bede747 100644
--- a/src/vnet/pg/pg.h
+++ b/src/vnet/pg/pg.h
@@ -306,6 +306,15 @@
   PG_MODE_IP6,
 } pg_interface_mode_t;
 
+always_inline pcap_packet_type_t
+pg_intf_mode_to_pcap_packet_type (pg_interface_mode_t mode)
+{
+  if ((mode == PG_MODE_IP4) || (mode == PG_MODE_IP6))
+    return PCAP_PACKET_TYPE_ip;
+  else
+    return PCAP_PACKET_TYPE_ethernet;
+}
+
 typedef struct
 {
   /* TX lock */