passivedns/0002-Add-support-for-loopback-devices.patch

From 55ed09ab48c617f392bf3cc08bc02ea8249578c7 Mon Sep 17 00:00:00 2001
From: Shawn Michael <blkmajik@monkeyspunk.net>
Date: Wed, 8 Dec 2021 16:27:58 -0700
Subject: [PATCH 2/3] Add support for loopback devices

---
 src/passivedns.c | 14 ++++++++++++++
 src/passivedns.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/src/passivedns.c b/src/passivedns.c
index b2c2a03..b05d3ba 100644
--- a/src/passivedns.c
+++ b/src/passivedns.c
@@ -66,6 +66,7 @@ uint8_t signal_reopen_log_files = 0;
 static void usage();
 static void show_version();
 void check_vlan (packetinfo *pi);
+void prepare_null (packetinfo *pi);
 void prepare_raw (packetinfo *pi);
 void prepare_sll (packetinfo *pi);
 void prepare_eth (packetinfo *pi);
@@ -141,6 +142,9 @@ void got_packet(u_char *useless, const struct pcap_pkthdr *pheader,
     config.inpacket = 1;
 
     switch (config.linktype) {
+        case DLT_NULL:
+            prepare_null(pi);
+            break;
         case DLT_RAW:
             prepare_raw(pi);
             break;
@@ -173,6 +177,16 @@ void got_packet(u_char *useless, const struct pcap_pkthdr *pheader,
     config.inpacket = 0;
 }
 
+void prepare_null(packetinfo *pi)
+{
+    pi->eth_hlen = LOOPBACK_HDR_LEN;
+    if ((u_int32_t)*pi->packet == AF_INET) {
+        pi->eth_type = ETHERNET_TYPE_IP;
+    } else {
+        pi->eth_type = ETHERNET_TYPE_IPV6;
+    }
+}
+
 void prepare_raw(packetinfo *pi)
 {
     pi->eth_hlen = 0;
diff --git a/src/passivedns.h b/src/passivedns.h
index 1031104..594852d 100644
--- a/src/passivedns.h
+++ b/src/passivedns.h
@@ -54,6 +54,7 @@
 #define IP6_PROTO_ICMP                58
 
 #define SLL_HDR_LEN                   16
+#define LOOPBACK_HDR_LEN              4
 #define IP4_HEADER_LEN                20
 #define IP6_HEADER_LEN                40
 #define TCP_HEADER_LEN                20
-- 
2.37.3