// -*- Mode: Go; indent-tabs-mode: t -*-

/*
 * Copyright (C) 2016 Canonical Ltd
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package builtin

import (
	"github.com/snapcore/snapd/interfaces"
)

// http://bazaar.launchpad.net/~ubuntu-security/ubuntu-core-security/trunk/view/head:/data/apparmor/policygroups/ubuntu-core/16.04/firewall-control
const firewallControlConnectedPlugAppArmor = `
# Description: Can configure firewall. This is restricted because it gives
# privileged access to networking and should only be used with trusted apps.
# Usage: reserved

#include <abstractions/nameservice>

capability net_admin,

/{,usr/}{,s}bin/iptables{,-save,-restore} ixr,
/{,usr/}{,s}bin/ip6tables{,-save,-restore} ixr,
/{,usr/}{,s}bin/iptables-apply ixr,
/{,usr/}{,s}bin/xtables-multi ixr, # ip[6]tables*

# ping - child profile would be nice but seccomp causes problems with that
/{,usr/}{,s}bin/ping ixr,
/{,usr/}{,s}bin/ping6 ixr,
capability net_raw,
capability setuid,
network inet raw,
network inet6 raw,

# iptables (note, we don't want to allow loading modules, but
# we can allow reading @{PROC}/sys/kernel/modprobe). Also,
# snappy needs to have iptable_filter and ip6table_filter loaded,
# they don't autoload.
unix (bind) type=stream addr="@xtables",
/{,var/}run/xtables.lock rwk,
@{PROC}/sys/kernel/modprobe r,

@{PROC}/@{pid}/net/ r,
@{PROC}/@{pid}/net/** r,

# sysctl
/{,usr/}{,s}bin/sysctl ixr,
@{PROC}/sys/ r,
@{PROC}/sys/net/ r,
@{PROC}/sys/net/core/ r,
@{PROC}/sys/net/core/** r,
@{PROC}/sys/net/ipv{4,6}/ r,
@{PROC}/sys/net/ipv{4,6}/** r,
@{PROC}/sys/net/netfilter/ r,
@{PROC}/sys/net/netfilter/** r,
@{PROC}/sys/net/nf_conntrack_max r,

# various firewall related sysctl files
@{PROC}/sys/net/ipv4/conf/*/rp_filter w,
@{PROC}/sys/net/ipv{4,6}/conf/*/accept_source_route w,
@{PROC}/sys/net/ipv{4,6}/conf/*/accept_redirects w,
@{PROC}/sys/net/ipv4/icmp_echo_ignore_broadcasts w,
@{PROC}/sys/net/ipv4/icmp_ignore_bogus_error_responses w,
@{PROC}/sys/net/ipv4/icmp_echo_ignore_all w,
@{PROC}/sys/net/ipv4/ip_forward w,
@{PROC}/sys/net/ipv4/conf/*/log_martians w,
@{PROC}/sys/net/ipv4/tcp_syncookies w,
@{PROC}/sys/net/ipv6/conf/*/forwarding w,
`

// http://bazaar.launchpad.net/~ubuntu-security/ubuntu-core-security/trunk/view/head:/data/seccomp/policygroups/ubuntu-core/16.04/firewall-control
const firewallControlConnectedPlugSecComp = `
# Description: Can configure firewall. This is restricted because it gives
# privileged access to networking and should only be used with trusted apps.
# Usage: reserved

# for connecting to xtables abstract socket
bind
connect
getsockname
getsockopt
recv
recvfrom
recvmsg
recvmmsg
send
sendmmsg
sendmsg
sendto
setsockopt
socket

# for ping and ping6
capset
setuid
`

const firewallControlConnectedPlugKmod = `
ip6table_filter
iptable_filter
`

// NewFirewallControlInterface returns a new "firewall-control" interface.
func NewFirewallControlInterface() interfaces.Interface {
	return &commonInterface{
		name: "firewall-control",
		connectedPlugAppArmor: firewallControlConnectedPlugAppArmor,
		connectedPlugSecComp:  firewallControlConnectedPlugSecComp,
		connectedPlugKMod:     firewallControlConnectedPlugKmod,
		reservedForOS:         true,
	}
}
