From fb716f036f2dcc480b50e094351c908720389188 Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Thu, 9 Dec 2021 00:44:57 +0000
Subject: [PATCH] Make dropcount not stupid slow

---
 dropcount.sh | 42 ++++++++++++++++++------------------------
 1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/dropcount.sh b/dropcount.sh
index 5f15b5e..6278955 100755
--- a/dropcount.sh
+++ b/dropcount.sh
@@ -1,47 +1,41 @@
 #!/bin/bash
-function PRINTCNT() {
-if [ "$1" != "" ]; then
-	if [ "$1" = "0" ]; then
-		echo -e "$2\t$3\tInvalid packet length"
-	elif [ "$1" = "1" ]; then
-		echo -e "$2\t$3\tInvalid VLAN tag"
-	elif [ "$1" = "2" ]; then
-		echo -e "$2\t$3\tInvalid/rejected IHL IPv4 field"
-	elif [ "$1" = "3" ]; then
-		echo -e "$2\t$3\tRejected IPv6 fragments"
-	else
-		echo -en "$2\t$3\t"
-		cat "$(dirname ${BASH_SOURCE[0]})/installed-rules.txt" | head -n $(( $1 - 3 )) | tail -n1
-	fi
-fi
-CNT=0
-}
 MAP_CONTENTS="$(bpftool map show | grep drop_cnt_map | awk '{ print $1 }' | tr -d ':' | while read IF; do
-	bpftool map dump id "$IF" | grep "bytes\|packets\|key" | grep -v '\(bytes\|packets\)": 0\(,\)*$'
+	bpftool map dump id "$IF" | grep "bytes\|packets\|key" | grep -v '\(bytes\|packets\)": 0\(,\)*$' | tr -d ','
 done)"
 echo "$MAP_CONTENTS" | {
 	declare -a BYTES
 	declare -a PACKETS
+	TOTAL_PACKETS=0
+	TOTAL_BYTES=0
 	KEY=""
 	while read LINE; do
 		case "$LINE" in
 			*"key"*)
-				KEY=$(echo "$LINE" | awk '{ print $2 }' | tr -d ',')
+				KEY=${LINE:7}
 				if [ "${BYTES["${KEY}"]}" = "" ]; then
 					BYTES["${KEY}"]=0
 					PACKETS["${KEY}"]=0
 				fi
 				;;
 			*"bytes"*)
-				BYTES["${KEY}"]=$(( ${BYTES["$KEY"]} + $(echo "$LINE" | awk '{ print $2 }' | tr -d ',') ))
+				BYTES["${KEY}"]=$(( ${BYTES["$KEY"]} + ${LINE:9} ))
+				TOTAL_BYTES=$(( $TOTAL_BYTES + ${LINE:9} ))
 				;;
 			*"packets"*)
-				PACKETS["$KEY"]=$(( ${PACKETS["$KEY"]} + $(echo "$LINE" | awk '{ print $2 }' | tr -d ',') ))
+				PACKETS["$KEY"]=$(( ${PACKETS["$KEY"]} + ${LINE:11} ))
+				TOTAL_PACKETS=$(( $TOTAL_PACKETS + ${LINE:11} ))
 				;;
 		esac
 	done
 	echo -e "pkts\tKBytes\tRule"
-	for C in "${!BYTES[@]}"; do
-		PRINTCNT $C "${PACKETS["$C"]}" "$(( ${BYTES["$C"]} / 1000 ))"
-	done
+	echo -e "${TOTAL_PACKETS}\t$(( ${TOTAL_BYTES} / 1000 ))\tTotal"
+	echo -e "${PACKETS[0]}\t$(( ${BYTES[0]} / 1000 ))\tInvalid packet length"
+	echo -e "${PACKETS[1]}\t$(( ${BYTES[1]} / 1000 ))\tInvalid VLAN tag"
+	echo -e "${PACKETS[2]}\t$(( ${BYTES[2]} / 1000 ))\tInvalid/rejected IHL IPv4 field"
+	echo -e "${PACKETS[3]}\t$(( ${BYTES[3]} / 1000 ))\tRejected IPv6 fragments"
+	C=4
+	while read LINE; do
+		echo -e "${PACKETS["$C"]}\t$(( ${BYTES["$C"]} / 1000 ))\t$LINE"
+		C=$(( $C + 1 ))
+	done < "$(dirname ${BASH_SOURCE[0]})/installed-rules.txt"
 }
-- 
2.39.5