[PATCH 04/11] bugfix: detstats(), ifstats(): handle packets with incorrect header checksum

[Vitezslav Samel]

detstats() and ifstats() could not account bad IPv4 packets (packets
with invalid header checksum) because since version iptraf-3.0.0 we
are dropping them. This causes the BadIP column be always zero.

Fix this by allowing pkt_result value CHECKSUM_ERROR to continue down
the code.

Signed-off-by: Vitezslav Samel <vitezslav(a)samel.cz&gt;
---
 src/detstats.c |   18 ++++++++++--------
 src/ifstats.c  |   17 ++++++++++-------
 2 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/src/detstats.c b/src/detstats.c
index 5783fd6..646893f 100644
--- a/src/detstats.c
+++ b/src/detstats.c
@@ -253,8 +253,6 @@ void detstats(char *iface, time_t facilitytime)
 	WINDOW *statwin;
 	PANEL *statpanel;
 
-	int pkt_result = 0;
-
 	FILE *logfile = NULL;
 
 	unsigned int iplen = 0;
@@ -518,14 +516,18 @@ void detstats(char *iface, time_t facilitytime)
 
 		int outgoing;
 
-		pkt_result =
-			packet_process(&pkt, NULL, NULL, NULL,
-				       MATCH_OPPOSITE_USECONFIG,
-				       options.v6inv4asv6);
+		int pkt_result = packet_process(&pkt, NULL, NULL, NULL,
+						MATCH_OPPOSITE_USECONFIG,
+						options.v6inv4asv6);
 
-		if (pkt_result != PACKET_OK
-		    && pkt_result != MORE_FRAGMENTS)
+		switch (pkt_result) {
+		case PACKET_OK:			/* we only handle these */
+		case MORE_FRAGMENTS:
+		case CHECKSUM_ERROR:
+			break;
+		default:			/* drop others */
 			continue;
+		}
 
 		outgoing = (pkt.pkt_pkttype == PACKET_OUTGOING);
 		update_proto_counter(&ifcounts.total, outgoing, pkt.pkt_len);
diff --git a/src/ifstats.c b/src/ifstats.c
index 2b009e5..2eb51b6 100644
--- a/src/ifstats.c
+++ b/src/ifstats.c
@@ -411,8 +411,6 @@ void ifstats(time_t facilitytime)
 	int logging = options.logging;
 	struct iftab table;
 
-	int pkt_result = 0;
-
 	struct iflist *ptmp = NULL;
 
 	FILE *logfile = NULL;
@@ -570,13 +568,18 @@ void ifstats(time_t facilitytime)
 		if (pkt.pkt_len <= 0)
 			continue;
 
-		pkt_result = packet_process(&pkt, NULL, NULL, NULL,
-					   MATCH_OPPOSITE_USECONFIG,
-					   options.v6inv4asv6);
+		int pkt_result = packet_process(&pkt, NULL, NULL, NULL,
+						MATCH_OPPOSITE_USECONFIG,
+						options.v6inv4asv6);
 
-		if (pkt_result != PACKET_OK
-		    && pkt_result != MORE_FRAGMENTS)
+		switch (pkt_result) {
+		case PACKET_OK:			/* we only handle these */
+		case MORE_FRAGMENTS:
+		case CHECKSUM_ERROR:
+			break;
+		default:			/* drop others */
 			continue;
+		}
 
 		ptmp = positionptr(table.head, pkt.pkt_ifindex);
 		if (!ptmp)
-- 
1.7.8.4