On Sun, Aug 06, 2023 at 08:00:11PM +0000, Bastian Bittorf wrote:
> Hello hackers,
>
> according to 'man dnsmasq' the var DNSMASQ_INTERFACE stores the name
> of the interface on which the request arrived; this is not set for "old"
> actions when dnsmasq restarts.
>
> all this in done in src/helper.c:
> my_setenv("DNSMASQ_INTERFACE", strlen(data.interface) != 0 ? data.interface :
> NULL, &err);
>
> With my (up-to-date) OpenWRT setup this seems sometimes not the case.
> Ontop of my dhcp-script.sh[1] i do (something like):
>
>
> #!/bin/sh
> MODE="$1"
> MAC="$2"
> IP="$3"
> HOST="$4"
>
> if [ -n "$DNSMASQ_INTERFACE" ]; then
> log "provided dev: $DNSMASQ_INTERFACE mode: $MODE mac: $MAC ip: $IP host:
> $HOST"
> else
> DEV="$( guess_dev "$IP" )"
> log "guessed dev: $DEV mode: $MODE mac: $MAC ip: $IP host: $HOST"
> fi
>
>
> Here the log output, when env-var DNSMASQ_INTERFACE is empty/unset and MODE
> is arp-add/add(!):
> There are 2 interesting lines - both from the same client (linux, under my
> control):
>
> provided dev: br-mastergate mode: old mac: e4:f8:9c:73:8b:1f ip:
> 100.66.19.131 host: filmforecast
> guessed dev: br-mastergate mode: add mac: e4:f8:9c:73:8b:1f ip:
> 100.66.19.131 host: unset
>
> root@box:~ logread | grep e4:f8:9c:73:8b:1f
> Sun Aug 6 21:12:38 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_script() provided dev: br-mastergate mode: old mac: e4:f8:9c:73:8b:1f
> ip: 100.66.19.131 host: filmforecast
Network 19
> Sun Aug 6 21:12:38 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_old() 'e4:f8:9c:73:8b:1f' is from 'br-mastergate' = roaming-DEV HOST:
> filmforecast
> Sun Aug 6 21:16:01 2023 daemon.info hostapd: phy1-ap0: STA e4:f8:9c:73:8b:1f
> IEEE 802.11: authenticated
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/sbin/cron.wireless_:
> iwevent() EVENT 6993: 'phy1-ap0: new station e4:f8:9c:73:8b:1f'
> Sun Aug 6 21:16:01 2023 daemon.info hostapd: phy1-ap0: STA e4:f8:9c:73:8b:1f
> IEEE 802.11: associated (aid 3)
> Sun Aug 6 21:16:01 2023 daemon.notice hostapd: phy1-ap0: AP-STA-CONNECTED
> e4:f8:9c:73:8b:1f auth_alg=open
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPREQUEST(br-mastergate) 100.65.42.131 e4:f8:9c:73:8b:1f
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPNAK(br-mastergate) 100.65.42.131 e4:f8:9c:73:8b:1f wrong address
Network 42 DHCPREQUEST _and_ DHCPNAK
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/sbin/cron.wireless_:
> wifi_signal_get() dev: phy1-ap0 mac: e4:f8:9c:73:8b:1f try: 3 signal: -64
> file: ''
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/sbin/cron.wireless_:
> iwevent() worker(7175) dev:phy1-ap0 ch:5 MODE: new MAC: e4:f8:9c:73:8b:1f -
> signal: '-64' border: '-73' try: 4
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/sbin/cron.wireless_:
> iwevent() mac2ipv4(20) grabbed ip from arp: e4:f8:9c:73:8b:1f -> 100.65.42.131
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/sbin/cron.wireless_:
> iwevent() worker(7175) dev:phy1-ap0 ch:5 MODE: new MAC: e4:f8:9c:73:8b:1f -
> ip: '100.65.42.131' signal: '-64' (is_good)
Network 42
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPDISCOVER(br-mastergate) 100.65.42.131 e4:f8:9c:73:8b:1f
A discover, usualy 0.0.0.0, this time 100.65.42.131 (Note the 42)
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPOFFER(br-mastergate) 100.66.19.131 e4:f8:9c:73:8b:1f
Note the 19
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPREQUEST(br-mastergate) 100.66.19.131 e4:f8:9c:73:8b:1f
> Sun Aug 6 21:16:01 2023 daemon.info dnsmasq-dhcp[19331]:
> DHCPACK(br-mastergate) 100.66.19.131 e4:f8:9c:73:8b:1f filmforecast
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_script() provided dev: br-mastergate mode: old mac: e4:f8:9c:73:8b:1f
> ip: 100.66.19.131 host: filmforecast
dhcp_script
> Sun Aug 6 21:16:01 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_old() 'e4:f8:9c:73:8b:1f' is from 'br-mastergate' = roaming-DEV HOST:
> filmforecast
dhcp_old
70 seconds
> Sun Aug 6 21:17:11 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_script() guessed dev: br-mastergate mode: add mac: e4:f8:9c:73:8b:1f ip:
> 100.66.19.131 host: unset
dhcp_script
> Sun Aug 6 21:17:11 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> dhcp_add() 'e4:f8:9c:73:8b:1f' is from 'br-mastergate' = roaming-DEV HOST:
> unset
dhcp_add
> Sun Aug 6 21:17:11 2023 daemon.info kalua: /usr/lib/dnsmasq/dhcp-sc:
> F36-stube_dhcp-add() [OK] _weblogin login_check e4:f8:9c:73:8b:1f
dhcp_F36-stube_dhcp-add
>
> the environment during the "guessed dev" call (without DNSMASQ_INTERFACE set)
> was written ontop of the dhcp-script with:
> {
> echo "# $@"
> set
> } >>"/tmp/dhcp-$2-$1-$3"
>
> root@F36-stube:~ cat /tmp/dhcp-e4:f8:9c:73:8b:1f-arp-add-100.66.19.131
> # arp-add e4:f8:9c:73:8b:1f 100.66.19.131
> FUNCNAME=''
> HOME='/'
> HOSTNAME='F36-stube'
> IFS='
> '
> LINENO=''
> OPTIND='1'
> PATH='/usr/sbin:/usr/bin:/sbin:/bin'
> PPID='19337'
> PS1='\w \$ '
> PS2='> '
> PS4='+ '
> PWD='/'
> SHLVL='1'
> TERM='linux'
> USER_DHCPSCRIPT='/etc/dhcp-script.d/10dhcpscript'
>
> root@F36-stube:~ dnsmasq --version
> Dnsmasq version 2.89 Copyright (c) 2000-2022 Simon Kelley
> ...
>
> Maybe somebody has an idea why this can happen, looking through the
> source it is not obvious and *should not happen* 8-) => except
> 'data.interface' is unknown.
> This happens on different CPU architectures, at least: mips, arm and powerpc.
>
> I'am happy to test patches or suggestions.
Suggestion: Dig deeper
> Thanks for your great work & bye,
> Bastian Bittorf
Groeten
Geert Stappers
[1]
#!/bin/sh
. /tmp/loader
MODE="${1:-unset}"
MAC="${2:-ff:00:00:00:00:00}" # FIXME! this enforces an invalid mac,
see sanitizer_mac()
IP="${3:-127.0.0.1}"
HOST="${4:-unset}"
case "$MODE" in
arp-add) MODE=add ;;
arp-del) MODE=del ;;
old) test -e /tmp/CRON_OVERLOAD && exit 0 ;;
esac
case "$MAC" in
'00:00:00:00:00:00')
MODE='cron-watchdog'
;;
*'-'*)
_log it dhcp_script daemon info "ignore non-ethernet events:
$MAC"
exit 0
;;
esac
if [ -n "$DNSMASQ_INTERFACE" ]; then
# see: man dnsmasq - we get some env vars, debug with 'set >/tmp/foo'
ontop of this script
# DNSMASQ_CLIENT_ID
# DNSMASQ_DATA_MISSING
# DNSMASQ_DOMAIN
# DNSMASQ_INTERFACE => DNSMASQ_INTERFACE stores the name of the
interface on which the request arrived; this is not set for "old" actions when
dnsmasq restarts.
# DNSMASQ_LEASE_EXPIRES
# DNSMASQ_TIME_REMAINING
export DNSMASQ_INTERFACE # needed in
netfilter_user_reachable()
DEV="$DNSMASQ_INTERFACE"
_log it dhcp_script daemon info "provided dev: $DEV mode: $MODE mac:
$MAC ip: $IP host: $HOST"
elif [ -e "$TMPDIR/firmware_burn" ]; then
exit 0
else
case "$IP" in fe80::*) exit 0 ;; esac # ignore IPv6 linklocal,
ip2dev() does not work here reliable anyway
#
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2023q3/017193.html
DEV="$( _net ip2dev $IP )"
_log it dhcp_script daemon info "guessed dev: $DEV mode: $MODE mac:
$MAC ip: $IP host: $HOST"
fi
case "$DEV" in
'br-mastergate')
TYPE='roaming'
case "$MODE" in
'add')
echo "$MAC $IP $DNSMASQ_LEASE_EXPIRES"
>>"$TMPDIR/roaming_dhcp_worker"
# recent entries on top ("tac")
grep -sn '' "$TMPDIR/roaming_dhcp_worker" |
sort -rn | cut -d: -f2- >"$TMPDIR/roaming_dhcp"
;;
'del')
sed -i "/^$MAC/d" "$TMPDIR/roaming_dhcp_worker"
sed -i "/^$MAC/d" "$TMPDIR/roaming_dhcp"
;;
esac
;;
$WANDEV)
TYPE='wan'
;;
$LANDEV)
TYPE='lan'
case "$MODE" in
'add'|'old')
bool_true
'system.@monitoring[0].report_lan_dhcp' && {
SHOW_HOST="$HOST"
[ "$SHOW_HOST" = 'unset' ] &&
SHOW_HOST="$( _net mac2vendor "$MAC" short )"
echo >>$SCHEDULER_IMPORTANT "_log
remote 'lan_dhcp: date: $( date ) CLIENT: mac: $MAC ip: $IP hostname:
$SHOW_HOST ROUTER: $HOSTNAME'"
}
;;
esac
;;
$WIFIDEV)
TYPE='wifi'
;;
$LODEV)
TYPE='loopback'
;;
'by-mybridge'|'gateway0') # just for better logging
TYPE='batman'
;;
*)
TYPE='unknown'
;;
esac
case "$HOST" in
'reanimateV2')
# seed watch_reanimate_dead_neighbour()
MODE='invalid'
_http robotstxt_generate
;;
esac
if [ "$MODE" = 'old' ]; then
_log it dhcp_$MODE daemon info "'$MAC' is from '$DEV' = ${TYPE}-DEV
HOST: $HOST"
else
_log it dhcp_$MODE daemon info "'$MAC' is from '$DEV' = ${TYPE}-DEV
HOST: $HOST"
case "$MODE-$HOST" in
'add-check_if_reachable')
MODE="$HOST"
_log it dhcp_add_check_if_reachable daemon info "MAC:
$MAC IP: $IP DEV: $DEV"
_netfilter user_add "$MAC" "$IP"
;;
esac
fi
case "$MODE" in
add|old)
bool_true 'system.@weblogin[0].enabled' && {
case "$MODE" in
'old')
_netfilter user_probe "$MAC" && exit 0
# maybe unknown after unscheduled
reboot, so go further
;;
'add')
case "$TYPE" in
'roaming')
echo
>>$SCHEDULER_IMPORTANT "_net roaming_report_new $MAC $IP $DNSMASQ_LEASE_EXPIRES"
;;
esac
;;
esac
USER="$MAC"
SIGNAL="${HOSTNAME}_dhcp-${MODE}"
# keyword 'dhcp' is important for login_check()
export REMOTE_ADDR="$IP"
if _weblogin login_check "$USER" '' "$MAC" "$SIGNAL" ;
then
# for "very fast unsplashing" and not showing
'please use credentials'
$IPT -t mangle -I PREROUTING -j ACCEPT
_log it $SIGNAL daemon info "[OK] _weblogin
login_check $USER"
_netfilter user_add "$MAC" "$IP"
# remove the hack for "very fast unsplashing"
$IPT -t mangle -D PREROUTING -j ACCEPT
else
if _weblogin login_check "$USER" "$HOSTNAME"
"$MAC" "$SIGNAL" ; then
_log it $SIGNAL daemon info "[OK]
_weblogin login_check $USER/$HOSTNAME (2nd try)"
_netfilter user_add "$MAC" "$IP"
else
_log it $SIGNAL daemon info "[ERR]
_weblogin login_check $USER/$HOSTNAME"
fi
fi
}
echo >>$SCHEDULER "_netfilter portforwarding_request $IP $MAC
$HOST"
;;
del)
# if bool_true 'system.@weblogin[0].dhcpautologout'; then
echo >>$SCHEDULER "_netfilter user_del $MAC dhcp_del"
# else
# _netfilter set_arp reachable "$MAC" "$IP" "$DEV"
# fi
;;
esac
# wrong place but works:
[ -e '/etc/crontabs/root' ] && {
[ $( _stopwatch stop '/tmp/CRON_LASTCALL' interim,nolog,seconds ) -gt
900 ] && {
mkdir '/tmp/LOCK_dhcpscript_cron_restart' && {
_stopwatch start '/tmp/CRON_LASTCALL' global
_log it watch_cron daemon alert "cron died, restarting"
/etc/init.d/S51crond_fff+ restart
rm -fR '/tmp/LOCK_dhcpscript_cron_restart'
}
}
}
true
--
Silence is hard to parse
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