diff options
Diffstat (limited to 'roles/common')
| -rwxr-xr-x | roles/common/files/etc/network/if-post-down.d/iptables | 27 | ||||
| -rwxr-xr-x | roles/common/files/etc/network/if-up.d/ipsec | 44 | ||||
| -rwxr-xr-x | roles/common/files/usr/local/sbin/update-firewall.sh | 71 | ||||
| -rw-r--r-- | roles/common/handlers/main.yml | 6 | ||||
| -rw-r--r-- | roles/common/tasks/firewall.yml | 8 | ||||
| -rw-r--r-- | roles/common/tasks/ipsec.yml | 16 |
6 files changed, 156 insertions, 16 deletions
diff --git a/roles/common/files/etc/network/if-post-down.d/iptables b/roles/common/files/etc/network/if-post-down.d/iptables new file mode 100755 index 0000000..944ff3a --- /dev/null +++ b/roles/common/files/etc/network/if-post-down.d/iptables @@ -0,0 +1,27 @@ +#!/bin/sh +# +# A post-down hook to flush ip tables and delete custom chains in the +# loaded v4 and v6 rulesets. +# +# Copyright 2013 Guilhem Moulin <guilhem@fripost.org> +# +# Licensed under the GNU GPL version 3 or higher. +# + +set -ue +PATH=/usr/sbin:/usr/bin:/sbin:/bin + +# Ignore the loopback interface; run the script for ifdown only. +[ "$IFACE" != lo -a "$MODE" = stop ] || exit 0 + +case "$ADDRFAM" in + inet) ipts=/sbin/iptables-save; ipt=/sbin/iptables;; + inet6) ipts=/sbin/ip6tables-save; ipt=/sbin/ip6tables;; + *) exit 0 +esac + +$ipts | sed -nr 's/^\*//p' | \ +while read table; do + $ipt -t "$table" -F + $ipt -t "$table" -X +done diff --git a/roles/common/files/etc/network/if-up.d/ipsec b/roles/common/files/etc/network/if-up.d/ipsec new file mode 100755 index 0000000..e21d6ea --- /dev/null +++ b/roles/common/files/etc/network/if-up.d/ipsec @@ -0,0 +1,44 @@ +#!/bin/sh +# +# A post-up/down hook to automatically create/delete a 'sec' VLAN +# device, and a dedicated, host-scoped, IP for IPSec (v4 only). +# +# Copyright 2013 Guilhem Moulin <guilhem@fripost.org> +# +# Licensed under the GNU GPL version 3 or higher. +# + +set -ue +PATH=/usr/sbin:/usr/bin:/sbin:/bin + +if=sec0 +ip=172.16.0.1/32 + +# Ignore the loopback interface and non inet4 families. +[ "$IFACE" != lo -a "$ADDRFAM" = inet ] || exit 0 + +# Only the device with the default, globally-scoped route, is of +# interest here. +[ "$( /bin/ip -4 route show to default scope global \ + | sed -nr '/^default via \S+ dev (\S+).*/ {s//\1/p;q}' )" \ + = \ + "$IFACE" ] || exit 0 + +case "$MODE" in + start) # Don't create $if if it's already there + /bin/ip -o link show | grep -qE "^[0-9]+:\s+$if" && exit 0 + + # Create a new VLAN $IFACE on physical device $if. This is + # required otherwise charon thinks the left peer is that + # host-scoped, non-routable IP. + /bin/ip link add link "$IFACE" name "$if" type vlan id 2713 + /bin/ip address add "$ip" dev "$if" scope host + /bin/ip link set dev "$if" up + ;; + stop) # Don't create $if if it's no there + /bin/ip -o link show | grep -qE "^[0-9]+:\s+$if" || exit 0 + + # Deactivate the VLAN + /bin/ip link set dev "$if" down + ;; +esac diff --git a/roles/common/files/usr/local/sbin/update-firewall.sh b/roles/common/files/usr/local/sbin/update-firewall.sh index 8530277..54a66e8 100755 --- a/roles/common/files/usr/local/sbin/update-firewall.sh +++ b/roles/common/files/usr/local/sbin/update-firewall.sh @@ -61,12 +61,26 @@ iptables() { # iptables-restore(8) instead. echo "$@" >> "$new"; } +commit() { + # End a table + echo COMMIT >> "$new" +} inet46() { case "$1" in 4) echo "$2";; 6) echo "$3";; esac } +ipt-chains() { + # Define new (tables and) chains. + while [ $# -gt 0 ]; do + case "$1" in + ?*:*) echo ":${1%:*} ${1##*:} [0:0]";; + ?*) echo "*$1";; + esac + shift + done >> "$new" +} ipt-trim() { # Remove dynamic chain/rules from the input stream, as they are @@ -134,15 +148,17 @@ run() { | sed -nr "/^[0-9]+:\s+(sec[0-9]+)@$if:\s.*/ {s//\1/p;q}" ) # The (host-scoped) IP reserved for IPSec. - local ipsec= + local ipsec= secmark if [ -n "$ifsec" -a $f = 4 ]; then tables+=( [$f]=' mangle nat' ) ipsec=$( /bin/ip -$f address show dev "$ifsec" scope host \ | sed -nr '/^\s+inet\s(\S+).*/ {s//\1/p;q}' ) + secmark=0x1 fi # Store the old (current) ruleset - local old=$(mktemp -t current-rules.v$f.XXXXXX) + local old=$(mktemp -t current-rules.v$f.XXXXXX) \ + new=$(mktemp -t new-rules.v$f.XXXXXX) for table in ${tables[$f]}; do $ipt-save -ct $table done > "$old" @@ -156,14 +172,35 @@ run() { fail2ban=1 fi + if [ -n "$ipsec" ]; then + # We DNAT the IPSec paquets to $ipsec after decapsulation, and + # SNAT them before encapsulation. We need to do the NAT'ing + # before packets enter the IPSec stack because they are signed + # afterwards, and NAT'ing would mess up the signature. + ipt-chains mangle PREROUTING:ACCEPT INPUT:ACCEPT \ + FORWARD:DROP \ + OUTPUT:ACCEPT POSTROUTING:ACCEPT + # Mark all IPSec packets to keep track of them and NAT them + # after decapsulation. Unmarked packets that are to be sent to + # $ipsec are dropped. + iptables -A PREROUTING -p esp -j MARK --set-mark $secmark + iptables -A INPUT -d "$ipsec" -m mark \! --mark $secmark -j DROP + commit + + ipt-chains nat PREROUTING:ACCEPT INPUT:ACCEPT \ + OUTPUT:ACCEPT POSTROUTING:ACCEPT + # DNAT all marked packets that have been decapsulated. Packets + # originating from our IPSec are SNAT'ed (MASQUERADE). We cannot + # mark them here (it won't survivethe NAT'ing), but any reply + # not going through IPSec would be dropped (since unmarked). + iptables -A PREROUTING \! -p esp -m mark --mark "$secmark" \ + -j DNAT --to "${ipsec%/*}" + iptables -A POSTROUTING -s "$ipsec" -j MASQUERADE + commit + fi + # The usual chains in filter, along with the desired default policies. - local new=$(mktemp -t new-rules.v$f.XXXXXX) - cat > "$new" <<- EOF - *filter - :INPUT DROP [0:0] - :FORWARD DROP [0:0] - :OUTPUT DROP [0:0] - EOF + ipt-chains filter INPUT:DROP FORWARD:DROP OUTPUT:DROP if [ -z "$if" ]; then # If the interface is not configured, we stop here and DROP all @@ -238,6 +275,14 @@ run() { iptables -A INPUT -i lo -s "$localhost" -d "$localhost" -j ACCEPT iptables -A OUTPUT -o lo -s "$localhost" -d "$localhost" -j ACCEPT + if [ -n "$ipsec" ]; then + # ACCEPT any, *marked* traffic destinating to the non-routable + # $ipsec. Also ACCEPT all traffic originating from $ipsec, as it + # is MASQUERADE'd. + iptables -A INPUT -i "$if" -d "$ipsec" -m mark --mark "$secmark" -j ACCEPT + iptables -A OUTPUT -s "$ipsec" -o "$if" -j ACCEPT + fi + # Prepare fail2ban. We make fail2ban insert its rules in a dedicated # chain, so that it doesn't mess up the existing rules. [ $fail2ban -eq 1 ] && iptables -A INPUT -i $if -j fail2ban @@ -296,11 +341,9 @@ run() { done ######################################################################## + commit - # Commit the table 'filter'. - echo COMMIT >> "$new" - local rv1=0 rv2=0 persistent=/etc/iptables/rules.v$f local oldz=$(mktemp -t current-rules.v$f.XXXXXX) @@ -311,7 +354,7 @@ run() { -e 's/^\[[0-9]+:[0-9]+\]\s+//' \ "$old" > "$oldz" - /usr/bin/uniq "$new" | /bin/ip netns exec $netns $ipt-restore + /usr/bin/uniq "$new" | /bin/ip netns exec $netns $ipt-restore || ipt-revert for table in ${tables[$f]}; do /bin/ip netns exec $netns $ipt-save -t $table @@ -327,7 +370,7 @@ run() { local update="Please run '${0##*/}'." if [ $check -eq 0 ]; then - /usr/bin/uniq "$new" | $ipt-restore + /usr/bin/uniq "$new" | $ipt-restore || ipt-revert else if [ $rv1 -ne 0 ]; then log "WARN: The IPv$f firewall is not up to date! $update" diff --git a/roles/common/handlers/main.yml b/roles/common/handlers/main.yml index a64a236..9cae8bf 100644 --- a/roles/common/handlers/main.yml +++ b/roles/common/handlers/main.yml @@ -19,3 +19,9 @@ - name: Restart IPSec service: name=ipsec state=restarted + +- name: Reload networking + # /etc/init.d/networking doesn't answer the status command; but since + # it should be "up" whenever ansible has access to the machine, we use + # pattern=init as a dummy assumption. + service: name=networking pattern=init state=reloaded diff --git a/roles/common/tasks/firewall.yml b/roles/common/tasks/firewall.yml index b1cd9b1..5029932 100644 --- a/roles/common/tasks/firewall.yml +++ b/roles/common/tasks/firewall.yml @@ -24,10 +24,14 @@ mode=0755 - name: Make the iptable ruleset persistent - copy: src=etc/network/if-pre-up.d/iptables - dest=/etc/network/if-pre-up.d/iptables + copy: src=etc/network/{{ item }} + dest=/etc/network/{{ item }} owner=root group=root mode=0755 + with_items: + - if-pre-up.d/iptables + - if-post-down.d/iptables + - name: Ensure the firewall is up to date command: /usr/local/sbin/update-firewall.sh -c diff --git a/roles/common/tasks/ipsec.yml b/roles/common/tasks/ipsec.yml index d4270d7..3d7a1dd 100644 --- a/roles/common/tasks/ipsec.yml +++ b/roles/common/tasks/ipsec.yml @@ -37,3 +37,19 @@ mode=0644 notify: - Restart IPSec + +- name: Auto-create a dedicated interface for IPSec + copy: src=etc/network/if-up.d/ipsec + dest=/etc/network/if-up.d/ipsec + owner=root group=root + mode=0755 + +# XXX: As of 1.3.1 ansible doesn't accept relative src. +# See https://github.com/ansible/ansible/issues/4459 +- name: Auto-deactivate the dedicated interface for IPSec + file: #src=../if-up.d/ipsec + src=/etc/network/if-up.d/ipsec + dest=/etc/network/if-down.d/ipsec + owner=root group=root state=link + notify: + - Reload networking |