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Firewall configuration /etc/config/firewall
OpenWrt's firewall management application fw3 has three provisioning mechanisms
Configuration files:
/etc/firewall.user/etc/config/firewall
Most of the information in this wiki will focus on the configuration files and content. The LuCI and UCI interfaces are user abstractions, ultimately modifying the configuration files.
Management
- The main firewall config file is
/etc/config/firewall, and this is edited to modify the firewall settingsCreate a backup of the firewall config prior to making changes
- Should changes cause a loss-of-connectivity to the router, you will need to access it in Failsafe Mode to restore the backup
- Once the settings are changed, and after double checking changes, reload the firewall via
/etc/init.d/firewall reload- This is a simple shell script calling
fw3 reload, and will print diagnostics to the console as it parses the new firewall configuration. Check for errors!
- Any line using
#in the first character is not parsed- Comments are utilized to describe, explain, or quickly comment out, a section
- The UCI firewall configuration in
/etc/config/firewallcovers a reasonable subset of NetFilter rules, but not all of them- To provide more functionality, an
includesection was added to the UCI firewall config that loads a file containing native iptables directives- This is processed as a shell script, allowing any shell command to be added to it, but the focus is working with the netfilter subsystem by adding iptables commands
- Whenever possible, use the fw3 firewall UCI config
- There are some scenarios where
iptablescommands are required- See Netfilter in OpenWrt for more information
Web interface
LuCI is a good mechanism to view and modify the firewall configuration.
- It is located under Network → Firewall and maps closely to the configuration file sections.
- It takes a little longer to modify the firewall configuration, but has a higher level of organization than the config files.
Make changes and reload using the Save & Apply button.
LuCI will remove all comment [
#] lines from/etc/config/firewall!
Command-line interface
UCI is a low-level abstraction to the configuration files and can be accessed remotely through SSH.
uci add firewall rule uci set firewall.@rule[-1].name='Reject VPN to LAN traffic' uci set firewall.@rule[-1].src='vpn' uci set firewall.@rule[-1].dest='lan' uci set firewall.@rule[-1].proto='all' uci set firewall.@rule[-1].target='REJECT' uci commit firewall service firewall restart
These would be presumed to be the final rules (each proto creates a rule) in the VPN → LAN forward chain, as all packets from VPN will be rejected.
Show firewall configuration:
# uci show firewall firewall.@rule[20]=rule firewall.@rule[20].name='Reject VPN to LAN traffic' firewall.@rule[20].src='vpn' firewall.@rule[20].dest='lan' firewall.@rule[20].proto='all' firewall.@rule[20].target='REJECT' ...
UCI is useful to view the firewall configuration, but not to do any meaningful modifications for the following reasons:
- Essential prior knowledge of where a firewall rule needs to go into the rule array in order to make it work (similar to
iptables -I) ucidoes not recognize content within the/etc/firewall.userscript.uci commitis necessary to save the changes, but still needs/etc/init.d/firewall reloadto reload new tables.
Config Sections
Below is an overview of the section types that may be defined in the firewall configuration.
- A minimal firewall configuration for a router usually consists of one defaults section, at least two zones (
lanandwan), and one forwarding to allow traffic fromlantowan.- The forwarding section is not strictly required when there are no more than two zones, as the rule can then be set as the 'global default' for that zone.
Defaults
The defaults section declares global firewall settings which do not belong to specific zones:
config defaults
option input 'ACCEPT'
option output 'ACCEPT'
option forward 'REJECT'
option custom_chains '1'
option drop_invalid '1'
option syn_flood '1'
option synflood_burst '50'
option synflood_protect '1'
option tcp_ecn '1'
option tcp_syncookies '1'
option tcp_window_scaling '1'
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
input | string | no | REJECT | Set policy for the INPUT chain of the filter table. |
forward | string | no | REJECT | Set policy for the FORWARD chain of the filter table. |
output | string | no | REJECT | Set policy for the OUTPUT chain of the filter table. |
drop_invalid | boolean | no | 0 | Drop invalid packets (e.g. not matching any active connection). |
syn_flood | boolean | no | 0 | Enable SYN flood protection (obsoleted by synflood_protect setting). |
synflood_protect | boolean | no | 0 | Enable SYN flood protection. |
synflood_rate | string | no | 25 | Set rate limit (packets/second) for SYN packets above which the traffic is considered a flood. |
synflood_burst | string | no | 50 | Set burst limit for SYN packets above which the traffic is considered a flood if it exceeds the allowed rate. |
tcp_syncookies | boolean | no | 1 | Enable the use of SYN cookies. |
tcp_ecn | boolean | no | 0 | Enable/Disable Explicit Congestion Notification. Implemented upstream in Linux Kernel. See ip-sysctl.txt. |
tcp_window_scaling | boolean | no | 1 | Enable TCP window scaling. |
accept_redirects | boolean | no | 0 | Accepts redirects. Implemented upstream in Linux Kernel. See ip-sysctl.txt. |
accept_source_route | boolean | no | 0 | Implemented upstream in Linux Kernel. See ip-sysctl.txt. |
custom_chains | boolean | no | 1 | Enable generation of custom rule chain hooks for user generated rules. User rules would be typically stored in firewall.user but some packages e.g. BCP38 also make use of these hooks. |
disable_ipv6 | boolean | no | 0 | Disable IPv6 firewall rules. |
flow_offloading | boolean | no | 0 | Enable software flow offloading for connections. (decrease cpu load / increase routing throughput) |
flow_offloading_hw | boolean | no | 0 | Enable hardware flow offloading for connections. (depends on flow_offloading and hw capability) |
tcp_reject_code | reject_code | no | 0 | Defined in firewall3/options.h. Seems to determine method of packet rejection; (tcp reset, or drop, vs ICMP Destination Unreachable, or closed) |
any_reject_code | reject_code | no | 1 | Defined in firewall3/options.h. Seems to determine method of packet rejection; (tcp reset, or drop, vs ICMP Destination Unreachable, or closed) |
auto-helper | bool | no | 1 | Enable Conntrack helpers |
Includes
It is possible to include custom firewall scripts by specifying one or more include sections in the firewall configuration:
config include
option path '/etc/firewall.user'
- The
/etc/firewall.userscript is empty by default.
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
enabled | boolean | no | 1 | Allows to disable the corresponding include without having to delete the section |
type | string | no | script | Specifies the type of the include, can be script for traditional shell script includes or restore for plain files in iptables-restore format |
path | file name | yes | /etc/firewall.user | Specifies a shell script to execute on boot or firewall restarts |
family | string | no | any | Specifies the address family (ipv4, ipv6 or any) for which the include is called |
reload | boolean | no | 0 | Specifies whether the include should be called on reload - this is only needed if the include injects rules into internal chains |
Includes of type script may contain arbitrary commands, for example advanced iptables rules or tc commands required for traffic shaping.
Since custom iptables rules are meant to be more specific than the generic ones, you must make sure to use
-I(insert), instead of-A(append), so that the rules appear before the default rules.If the rule exists in iptables, it will not be re-added. A standard iptables
-Ior-Awill add a duplicate rule.
Example
Here is an example of /etc/firewall.user script that allows to CloudFlare.com to access HTTP 80 and HTTPS 443 ports.
Use if your uhttpd is hidden behind CF proxy.
# Replace the ips-v4 with v6 if needed for ip in `wget -qO- http://www.cloudflare.com/ips-v4`; do iptables -I INPUT -p tcp -m multiport --dports http,https -s $ip -j ACCEPT done
NOTE: The example uses HTTP to get the list of IPs.
Using HTTP makes us vulnerable to MITM attacks.
To use the more secure HTTPS and avoid MITM risks, we need to install ca-certs.
Redirects
Port forwardings (DNAT) are defined by redirect sections.
Port Redirects are also commonly known as “port forwarding” or “virtual servers”.
- All incoming traffic on the specified source zone which matches the given rules will be directed to the specified internal host.
- Port ranges are specified as
start:stop, for instance6666:6670(similar to the iptables syntax).
Destination NAT
config redirect
option name 'DNAT WAN to LAN for SSH'
option src 'wan'
option src_dport '19900'
option dest 'lan'
option dest_ip '192.168.1.1'
option dest_port '22'
option proto 'tcp'
option target 'DNAT'
If a src_dport is not included in the config section, packets matching the other config options, on any port, will be forwarded to the destination port specified in that config section.
This could pose a security risk to the application running on the destination port the config section opens.
One way to test for this issue, is to use Gibson Research Corporation's ShieldsUP! service, and probe the desired ports on your router.
The response could be open, closed, or stealth (drop).
In cases of open or closed ports, packets are reaching a destination host, and are sending ack/reply packets back.
Whereas stealthed ports drop packets; from the perspective of the probing system (Gibson Research), that system cannot definitively know if those packets may, or may not be reaching the destination host.
Source NAT
Masquerade is the most common form of SNAT, changing the source of traffic to WAN to the router's public IP. SNAT can also be done manually:
config redirect
option name 'SNAT DMZ 192.168.1.250 to WAN 1.2.3.4 for ICMP'
option src 'dmz'
option src_ip '192.168.1.250'
option src_dip '1.2.3.4'
option dest 'wan'
option proto 'icmp'
option target 'SNAT'
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
name | string | no | string | Name of redirect |
src | zone name | yes for DNAT target | (none) | Specifies the traffic source zone. Must refer to one of the defined zone names. For typical port forwards this usually is wan. |
src_ip | ip address | no | (none) | Match incoming traffic from the specified source ip address. |
src_dip | ip address | yes for SNAT target | (none) | For DNAT, match incoming traffic directed at the given destination ip address. For SNAT rewrite the source address to the given address. |
src_mac | mac address | no | (none) | Match incoming traffic from the specified mac address. |
src_port | port or range | no | (none) | Match incoming traffic originating from the given source port or port range on the client host. |
src_dport | port or range | no | (none) | For DNAT, match incoming traffic directed at the given destination port or port range on this host. For SNAT rewrite the source ports to the given value. |
proto | protocol name or number | no | tcpudp | Match incoming traffic using the given protocol. Can be one (or several when using list syntax) of tcp, udp, tcpudp, udplite, icmp, esp, ah, sctp, or all or it can be a numeric value, representing one of these protocols or a different one. A protocol name from /etc/protocols is also allowed. The number 0 is equivalent to all. |
dest | zone name | yes for SNAT target | (none) | Specifies the traffic destination zone. Must refer to one of the defined zone names. For DNAT target on Attitude Adjustment, NAT reflection works only if this is equal to lan. |
dest_ip | ip address | no | (none) | For DNAT, redirect matches incoming traffic to the specified internal host. For SNAT, it matches traffic directed at the given address. For DNAT, if the dest_ip is not specified, the rule is translated in a iptables/REDIRECT rule, otherwise it is a iptables/DNAT rule. |
dest_port | port or range | no | (none) | For DNAT, redirect matched incoming traffic to the given port on the internal host. For SNAT, match traffic directed at the given ports. Only a single port or range can be specified, not disparate ports as with Rules (below). |
ipset | string | no | (none) | If specified, match traffic against the given ipset. The match can be inverted by prefixing the value with an exclamation mark. |
mark | string | no | (none) | If specified, match traffic against the given firewall mark, e.g. 0xFF to match mark 255 or 0x0/0x1 to match any even mark value. The match can be inverted by prefixing the value with an exclamation mark, e.g. !0x10 to match all but mark #16. |
start_date | date (yyyy-mm-dd) | no | (always) | If specifed, only match traffic after the given date (inclusive). |
stop_date | date (yyyy-mm-dd) | no | (always) | If specified, only match traffic before the given date (inclusive). |
start_time | time (hh:mm:ss) | no | (always) | If specified, only match traffic after the given time of day (inclusive). |
stop_time | time (hh:mm:ss) | no | (always) | If specified, only match traffic before the given time of day (inclusive). |
weekdays | list of weekdays | no | (always) | If specified, only match traffic during the given week days, e.g. sun mon thu fri to only match on Sundays, Mondays, Thursdays and Fridays. The list can be inverted by prefixing it with an exclamation mark, e.g. ! sat sun to always match but on Saturdays and sundays. |
monthdays | list of dates | no | (always) | If specified, only match traffic during the given days of the month, e.g. 2 5 30 to only match on every 2nd, 5th and 30rd day of the month. The list can be inverted by prefixing it with an exclamation mark, e.g. ! 31 to always match but on the 31st of the month. |
utc_time | boolean | no | 0 | Treat all given time values as UTC time instead of local time. |
target | string | no | DNAT | NAT target (DNAT or SNAT) to use when generating the rule. |
family | string | no | any | Protocol family (ipv4, ipv6 or any) to generate iptables rules for. |
reflection | boolean | no | 1 | Activate NAT reflection for this redirect - applicable to DNAT targets. |
reflection_src | string | no | internal | The source address to use for NAT-reflected packets if reflection is 1. This can be internal or external, specifying which interface’s address to use. Applicable to DNAT targets. |
limit | string | no | (none) | Maximum average matching rate; specified as a number, with an optional /second, /minute, /hour or /day suffix. Examples: 3/second, 3/sec or 3/s. |
limit_burst | integer | no | 5 | Maximum initial number of packets to match, allowing a short-term average above limit. |
enabled | string | no | 1 or yes | Enable the redirect rule or not. |
helper | cthelper | no | | |
See also: https://git.openwrt.org/?p=project/firewall3.git;a=blob;f=snats.c;hb=HEAD#l22
Zones
A zone section groups one or more interfaces and serves as a source or destination for forwardings, rules and redirects.
config zone
option name 'wan'
option network 'wan wan6'
option input 'REJECT'
option output 'ACCEPT'
option forward 'REJECT'
option masq '1'
option mtu_fix '1'
- MASQUERADE (NAT) of outgoing traffic (WAN) is controlled on a per-zone basis on the outgoing interface.
- INPUT rules for a zone describe what happens to traffic trying to reach the router itself through an interface in that zone.
- OUTPUT rules for a zone describe what happens to traffic originating from the router itself going through an interface in that zone.
- FORWARD rules for a zone describe what happens to traffic passing between different interfaces belonging in the same zone.
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
name | zone name | yes | (none) | Unique zone name. 11 characters is the maximum working firewall zone name length. |
network | list | no | (none) | List of interfaces attached to this zone. If omitted and neither extra* options, subnets nor devices are given, the value of name is used by default. Alias interfaces defined in the network config cannot be used as valid 'standalone' networks. Use list syntax . |
masq | boolean | no | 0 | Specifies whether outgoing zone traffic should be masqueraded. This is typically enabled on the wan zone. |
masq_src | list of subnets | no | 0.0.0.0/0 | Limit masquerading to the given source subnets. Negation is possible by prefixing the subnet with !; multiple subnets are allowed. |
masq_dest | list of subnets | no | 0.0.0.0/0 | Limit masquerading to the given destination subnets. Negation is possible by prefixing the subnet with !; multiple subnets are allowed. |
masq_allow_invalid | boolean | no | 0 | Do not add DROP INVALID rules, if masquerading is used. The DROP rules are supposed to prevent NAT leakage (see commit in firewall3). |
mtu_fix | boolean | no | 0 | Enable MSS clamping for outgoing zone traffic. |
input | string | no | DROP | Default policy (ACCEPT, REJECT, DROP) for incoming zone traffic. |
forward | string | no | DROP | Default policy (ACCEPT, REJECT, DROP) for forwarded zone traffic. |
output | string | no | DROP | Default policy (ACCEPT, REJECT, DROP) for outgoing zone traffic. |
family | string | no | any | The protocol family (ipv4, ipv6 or any) these iptables rules are for. |
log | int | no | 0 | Bit field to enable logging in the filter and/or mangle tables, bit 0 = filter, bit 1 = mangle. (Since r6397-7cc9914aae) |
log_limit | string | no | 10/minute | Limits the amount of log messages per interval. |
device | list | no | (none) | List of raw network device names attached to this zone, e.g. ppp+ to match any PPP interface. |
subnet | list | no | (none) | List of IP subnets attached to this zone. |
extra | string | no | (none) | Extra arguments passed directly to iptables. Note that these options are passed to both source and destination classification rules, therefor direction-specific options like --dport should not be used here - in this case the extra_src and extra_dest options should be used instead. |
extra_src | string | no | Value of extra | Extra arguments passed directly to iptables for source classification rules. |
extra_dest | string | no | Value of extra | Extra arguments passed directly to iptables for destination classification rules. |
custom_chains | bool | no | 1 | Enable generation of custom rule chain hooks for user generated rules. Has no effect if disabled (0) in the defaults section (see above). |
enabled | bool | no | yes | if set to 0, zone is disabled |
auto_helper | bool | no | 1 for non-masq zone | Add CT helpers for zone |
helper | cthelper | no | (none) | List of helpers to add to zone |
Forwardings
The forwarding sections control the traffic flow between zones, and may enable MSS clamping for specific directions.
config forwarding
option src 'lan'
option dest 'wan'
- Only one direction is covered by a
forwardingrule. To allow bidirectional traffic flows between two zones, two forwardings are required, withsrcanddestreversed in each.
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
name | forward name | no | (none) | Unique forwarding name. |
src | zone name | yes | (none) | Specifies the traffic source zone. Must refer to one of the defined zone names. For typical port forwards this usually is 'wan'. |
dest | zone name | yes | (none) | Specifies the traffic destination zone. Must refer to one of the defined zone names |
mtu_fix | | | 0 | zone sections in 8.09.2+) |
family | string | no | any | Protocol family (ipv4, ipv6 or any) to generate iptables rules for. |
enabled | bool | no | yes | if set to 0, forward is disabled |
The iptables rules generated for this section rely on the state match which needs connection tracking to work.
- At least one of the
srcordestzones needs to have connection tracking enabled through themasqoption.
Rules
The rule section is used to define basic accept, drop, or reject rules to allow or restrict access to specific ports or hosts.
config rule
option name 'Reject LAN to WAN for custom IP'
option src 'lan'
option src_ip '192.168.1.2'
option src_mac '00:11:22:33:44:55'
option src_port '80'
option dest 'wan'
option dest_ip '194.25.2.129'
option dest_port '120'
option proto 'tcp'
option target 'REJECT'
-
- If
srcanddestare given, the rule matches forwarded traffic - If only
srcis given, the rule matches incoming traffic - If only
destis given, the rule matches outgoing traffic - If neither
srcnordestare given, the rule defaults to an outgoing traffic rule
- Port ranges are specified as
start:stop, for instance6666:6670(similar to the iptables syntax).
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
name | string | no | (none) | Name of rule |
src | zone name | yes ( | (none) | Specifies the traffic source zone. Must refer to one of the defined zone names. |
src_ip | ip address | no | (none) | Match incoming traffic from the specified source ip address |
src_mac | mac address | no | (none) | Match incoming traffic from the specified mac address |
src_port | port or range | no | (none) | Match incoming traffic from the specified source port or port range, if relevant proto is specified. Multiple ports can be specified like '80 443 465' 1. |
proto | protocol name or number | no | tcpudp | Match incoming traffic using the given protocol. Can be one of tcp, udp, tcpudp, udplite, icmp, esp, ah, sctp, or all or it can be a numeric value, representing one of these protocols or a different one. A protocol name from /etc/protocols is also allowed. The number 0 is equivalent to all. |
icmp_type | list of type names or numbers | no | any | For protocol icmp select specific icmp types to match. Values can be either exact icmp type numbers or type names (see below). |
dest | zone name | no | (none) | Specifies the traffic destination zone. Must refer to one of the defined zone names, or * for any zone. If specified, the rule applies to forwarded traffic; otherwise, it is treated as input rule. |
dest_ip | ip address | no | (none) | Match incoming traffic directed to the specified destination ip address. With no dest zone, this is treated as an input rule! |
dest_port | port or range | no | (none) | Match incoming traffic directed at the given destination port or port range, if relevant proto is specified. Multiple ports can be specified like '80 443 465' 1. |
ipset | string | no | (none) | If specified, match traffic against the given ipset. The match can be inverted by prefixing the value with an exclamation mark. You can specify the direction as 'setname src' or 'setname dest'. The default if neither src nor dest are added is to assume src |
mark | mark/mask | no | (none) | If specified, match traffic against the given firewall mark, e.g. 0xFF to match mark 255 or 0x0/0x1 to match any even mark value. The match can be inverted by prefixing the value with an exclamation mark, e.g. !0x10 to match all but mark #16. |
start_date | date (yyyy-mm-dd) | no | (always) | If specifed, only match traffic after the given date (inclusive). |
stop_date | date (yyyy-mm-dd) | no | (always) | If specified, only match traffic before the given date (inclusive). |
start_time | time (hh:mm:ss) | no | (always) | If specified, only match traffic after the given time of day (inclusive). |
stop_time | time (hh:mm:ss) | no | (always) | If specified, only match traffic before the given time of day (inclusive). |
weekdays | list of weekdays | no | (always) | If specified, only match traffic during the given week days, e.g. sun mon thu fri to only match on sundays, mondays, thursdays and Fridays. The list can be inverted by prefixing it with an exclamation mark, e.g. ! sat sun to always match but on Saturdays and sundays. |
monthdays | list of dates | no | (always) | If specified, only match traffic during the given days of the month, e.g. 2 5 30 to only match on every 2nd, 5th and 30rd day of the month. The list can be inverted by prefixing it with an exclamation mark, e.g. ! 31 to always match but on the 31st of the month. |
utc_time | boolean | no | 0 | Treat all given time values as UTC time instead of local time. |
target | string | yes | DROP | Firewall action (ACCEPT, REJECT, DROP, MARK, NOTRACK) for matched traffic |
set_mark | mark/mask | yes for target MARK | (none) | Zeroes out the bits given by mask and ORs value into the packet mark. If mask is omitted, 0xFFFFFFFF is assumed |
set_xmark | Zeroes out the bits given by mask and XORs value into the packet mark. If mask is omitted, 0xFFFFFFFF is assumed | |||
family | string | no | any | Protocol family (ipv4, ipv6 or any) to generate iptables rules for. |
limit | string | no | (none) | Maximum average matching rate; specified as a number, with an optional /second, /minute, /hour or /day suffix. Examples: 3/minute, 3/min or 3/m. |
limit_burst | integer | no | 5 | Maximum initial number of packets to match, allowing a short-term average above limit |
extra | string | no | (none) | Extra arguments to pass to iptables. Useful mainly to specify additional match options, such as -m policy --dir in for IPsec. |
enabled | boolean | no | yes | Enable or disable rule. |
device | string | no | | |
direction | direction | no | | |
set_helper | cthelper | no | | |
helper | cthelper | no | | |
ICMP Name Types
address-mask-reply | host-redirect | pong | time-exceeded |
address-mask-request | host-unknown | port-unreachable | timestamp-reply |
any | host-unreachable | precedence-cutoff | timestamp-request |
communication-prohibited | ip-header-bad | protocol-unreachable | TOS-host-redirect |
destination-unreachable | network-prohibited | redirect | TOS-host-unreachable |
echo-reply | network-redirect | required-option-missing | TOS-network-redirect |
echo-request | network-unknown | router-advertisement | TOS-network-unreachable |
fragmentation-needed | network-unreachable | router-solicitation | ttl-exceeded |
host-precedence-violation | parameter-problem | source-quench | ttl-zero-during-reassembly |
host-prohibited | ping | source-route-failed | ttl-zero-during-transit |
Routing
IP Sets
fw3 supports referencing or creating ipsets to simplify matching of large address or port lists without the need for creating one rule per item to match.
This needs the
kmod-ipt-ipsetkernel module installed.
Options
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
enabled | boolean | no | 1 | Allows to disable the declaration of the ipset without the need to delete the section. |
external | string | no | (none) | If the external option is set to a name, the firewall will simply reference an already existing ipset pointed to by the name. If the external option is unset, the firewall will create the ipset on start and destroy it on stop. |
name | string | yes if external is unset no if external is set | (none) if external is unset value of external if external is set | Specifies the firewall internal name of the ipset which is used to reference the set in rules or redirects. |
family | string | no | ipv4 | Protocol family (ipv4 or ipv6) to create ipset for. Only applicable to storage types hash and list, the bitmap type implies ipv4. |
storage | string | no | varies | Specifies the storage method (bitmap, hash or list) used by the ipset, the default varies depending on the used datatypes (see match option below). In most cases the storage method can be automatically inferred from the datatype combination but in some cases multiple choices are possible (e.g. bitmap:ip vs. hash:ip). |
match | list of direction/type tuples | yes | (none) | Specifies the matched data types (ip, port, mac, net or set) and their direction (src or dest). The direction is joined with the datatype by an underscore to form a tuple, e.g. src_port to match source ports or dest_net to match destination CIDR ranges. When using ipsets matching on multiple elements, e.g. hash:ip,port, specify the packet fields to match on in quotes or comma-separated (i.e. “match dest_ip dest_port”). |
iprange | IP range | yes for storage type bitmap with datatype ip | (none) | Specifies the IP range to cover, see ipset(8). Only applicable to the hash storage type. |
portrange | Port range | yes for storage type bitmap with datatype port | (none) | Specifies the port range to cover, see ipset(8). Only applicable to the hash storage type. |
netmask | integer | no | 32 | If specified, network addresses will be stored in the set instead of IP host addresses. Value must be between 1 and 32, see ipset(8). Only applicable to the bitmap storage type with match ip or the hash storage type with match ip. |
maxelem | integer | no | 65536 | Limits the number of items that can be added to the set, only applicable to the hash and list storage types. |
hashsize | integer | no | 1024 | Specifies the initial hash size of the set, only applicable to the hash storage type. |
timeout | integer | no | 0 | Specifies the default timeout for entries added to the set. A value of 0 means no timeout. |
entry | setentry | no | | |
loadfile | string | no | | |
Storage / Match Options
The order of datatype matches is significant
| Family | Storage | Match | Notes |
|---|---|---|---|
ipv4 | bitmap | ip | Requires iprange option |
ipv4 | bitmap | ip mac | Requires iprange option |
ipv4 | bitmap | port | Requires portrange option |
| any | hash | ip | - |
| any | hash | net | - |
| any | hash | ip port | - |
| any | hash | net port | - |
| any | hash | ip port ip | - |
| any | hash | ip port net | - |
| - | list | set | Meta type to create a set-of-sets |
IPv6
As described above, the option family is used for distinguishing between IPv4, IPv6 and both protocols.
However the family is inferred automatically if IPv6 addresses are used:
config rule
option src 'wan'
option src_ip 'fdca:f00:ba3::/64'
option target 'ACCEPT'
Similar, such a rule is detected as IPv4 only:
config rule
option src 'wan'
option dest_ip '88.77.66.55'
option target 'REJECT'
- Rules without IP addresses are automatically added to iptables and ip6tables, unless overridden by the family option.
- Redirect rules (port forwards) are always IPv4 (for now) since there is no IPv6 DNAT support (yet).