From patchwork Thu Mar  8 20:24:55 2018
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Subject: [2/2] configurehood: Check for timestamp of hood file over LAN
From: Adrian Schmutzler <freifunk@adrianschmutzler.de>
X-Patchwork-Id: 816
Message-Id: <1520540695-4303-2-git-send-email-freifunk@adrianschmutzler.de>
To: franken-dev@freifunk.net
Date: Thu,  8 Mar 2018 21:24:55 +0100

This patch does no more take the first hood file it finds, but
compares the timestamps provided.

Additionally, we again started to check for the gateway at the
end, but only take the file if its newer and FROM THE SAME HOOD.

Thus, we enable updates, but prohobit switching from a cable
hood to a WiFi peer. (Bug # 68)

Fixes #95.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Tested-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
---

NOT TESTED!
---
 .../fff/fff-hoods/files/usr/sbin/configurehood     | 26 ++++++++++++++++------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/packages/fff/fff-hoods/files/usr/sbin/configurehood b/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
index 127ce5b..3a6fb9b 100755
--- a/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
+++ b/src/packages/fff/fff-hoods/files/usr/sbin/configurehood
@@ -145,6 +145,7 @@ else
 
 			# check eth first
 			oldhood=""
+			oldtime="0"
 			ethfile="${hoodfile}eth"
 			for eth in $(batctl if | grep "eth" | sed -nE 's/.*(eth[^:]+):.*/\1/p'); do
 				for mac in $(batctl n | grep "$eth" | sed -nE 's/.*eth[0-9.]+\s+([^\s]+)\s.*/\1/p'); do
@@ -154,6 +155,7 @@ else
 						json_load "$(cat "$ethfile")"
 						json_select hood
 						json_get_var newhood name
+						json_get_var newtime timestamp
 						if [ -n "$oldhood" ] && [ -n "$newhood" ] && ( ! [ "$newhood" = "$oldhood" ] ) ; then
 							# 2nd hood found, kill interface and go on (next try in 5 min.)
 							echo "Two hoods detected. Remove cables to stay in just one."
@@ -161,18 +163,28 @@ else
 							touch "$resetnetworkfile"
 							continue 2 # go to the next interface
 						fi
-						mv "$ethfile" "$hoodfile" # Only use hoodfile if sane
+						if [ "$oldtime" -lt "$newtime" ] ; then
+							mv "$ethfile" "$hoodfile" # Only use hoodfile if sane and newer
+							oldtime="$newtime"
+						fi
 						[ -n "$oldhood" ] || oldhood="$newhood" # only set oldhood once
 					fi
 				done
 			done
-			if [ ! -s "$hoodfile" ]; then
-				# Only load hoodfile from gateway if not already present from local network
-				# - This gives local network a precedence (take the hood from local network)
-				# - This prevents file insertion from a third person, as I will only connect via LAN to who I trust
-				wget -T15 -t5 "http://[fe80::1%br-mesh]:2342/keyxchangev2data" -O "$hoodfile"
+
+			# check gateway
+			wget -T15 -t5 "http://[fe80::1%br-mesh]:2342/keyxchangev2data" -O "$ethfile"
+			if [ -s "$ethfile" ]; then
+				json_load "$(cat "$ethfile")"
+				json_select hood
+				json_get_var newhood name
+				json_get_var newtime timestamp
+				if [ -z "$oldhood" ] || [ "$newhood" = "$oldhood" ] ; then
+					# Gateway on same hood, check for newer hood file
+					[ "$oldtime" -lt "$newtime" ] && mv "$ethfile" "$hoodfile" # Only use hoodfile if sane and newer
+				fi
 			fi
-			#UPLINK: Do nothing
+			#SECTORFILE: Do nothing
 		fi
 	fi
 fi