From 24df88633d2c9c642dcc3fa63c81093fb6ffb5fd Mon Sep 17 00:00:00 2001 From: rebortg Date: Thu, 23 Apr 2020 15:13:01 +0200 Subject: Firewall: rewrite Firewallsection --- docs/firewall.rst | 682 ++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 612 insertions(+), 70 deletions(-) diff --git a/docs/firewall.rst b/docs/firewall.rst index 12eae726..27dd11fd 100644 --- a/docs/firewall.rst +++ b/docs/firewall.rst @@ -3,6 +3,9 @@ Firewall ======== +Overview +-------- + VyOS makes use of Linux `netfilter `_ for packet filtering. @@ -19,18 +22,122 @@ or zone based firewall policy. interface. The `INPUT` chain, which is used for local traffic to the OS, is a reference to as `local` with respect to its input interface. -Zone-based Firewall Policy --------------------------- -As an alternative to applying policy to an interface directly, a -zone-based firewall can be created to simplify configuration when -multiple interfaces belong to the same security zone. Instead of -applying to rulesets to interfaces they are applied to source -zone-destination zone pairs. +Global settings +--------------- + +Some firewall settings are global and have a affect on the hole system. + +.. cfgcmd:: set firewall all-ping [enable | disable] + + By default, when VyOS receives an ICMP echo request packet destined for + itself, it will answer with an ICMP echo reply, unless you avoid it + through its firewall. + + With the firewall you can set rules to accept, drop or reject ICMP in, + out or local traffic. You can also use the general **firewall all-ping** + command. This command affects only to LOCAL (packets destined for your + VyOS system), not to IN or OUT traffic. + + .. note:: **firewall all-ping** affects only to LOCAL and it always + behaves in the most restrictive way + + .. code-block:: none + + set firewall all-ping enable + + When the command above is set, VyOS will answer every ICMP echo request + addressed to itself, but that will only happen if no other rule is + applied dropping or rejecting local echo requests. In case of conflict, + VyOS will not answer ICMP echo requests. + + .. code-block:: none + + set firewall all-ping disable + + When the command above is set, VyOS will answer no ICMP echo request + addressed to itself at all, no matter where it comes from or whether + more specific rules are being applied to accept them. + +.. cfgcmd:: set firewall broadcast-ping [enable | disable] + + This setting enable or disable the response of icmp broadcast + messages. The following system parameter will be altered: + + * ``net.ipv4.icmp_echo_ignore_broadcasts`` + +.. cfgcmd:: set firewall ip-src-route [enable | disable] +.. cfgcmd:: set firewall ipv6-src-route [enable | disable] + + This setting handle if VyOS accept packets with a source route + option. The following system parameter will be altered: + + * ``net.ipv4.conf.all.accept_source_route`` + * ``net.ipv6.conf.all.accept_source_route`` + +.. cfgcmd:: set firewall receive-redirects [enable | disable] +.. cfgcmd:: set firewall ipv6-receive-redirects [enable | disable] + + enable or disable of ICMPv4 or ICMPv6 redirect messages accepted + by VyOS. The following system parameter will be altered: + + * ``net.ipv4.conf.all.accept_redirects`` + * ``net.ipv6.conf.all.accept_redirects`` + +.. cfgcmd:: set firewall send-redirects [enable | disable] + + enable or disable of ICMPv4 redirect messages send by VyOS + The following system parameter will be altered: + + * ``net.ipv4.conf.all.send_redirects`` + +.. cfgcmd:: set firewall log-martians [enable | disable] + + enable or disable the logging of martian IPv4 packets. + The following system parameter will be altered: + + * ``net.ipv4.conf.all.log_martians`` + +.. cfgcmd:: set firewall source-validation [strict | loose | disable] + + Set the IPv4 source validation mode. + The following system parameter will be altered: + + * ``net.ipv4.conf.all.rp_filter`` + +.. cfgcmd:: set firewall syn-cookies [enable | disable] + + Enable or Disable if VyOS use IPv4 TCP SYN Cookies. + The following system parameter will be altered: + + * ``net.ipv4.tcp_syncookies`` + +.. cfgcmd:: set firewall twa-hazards-protection [enable | disable] + + Enable or Disable VyOS to be :rfc:`1337` conform. + The following system parameter will be altered: + + * ``net.ipv4.tcp_rfc1337`` + +.. cfgcmd:: set firewall state-policy established action [accept | drop | + reject] + +.. cfgcmd:: set firewall state-policy established log enable + + Set the global setting for a astablished connections. + +.. cfgcmd:: set firewall state-policy invalid action [accept | drop | reject] + +.. cfgcmd:: set firewall state-policy invalid log enable + + Set the global setting for invalid packets. + +.. cfgcmd:: set firewall state-policy related action [accept | drop | reject] + +.. cfgcmd:: set firewall state-policy related log enable + + Set the global setting for related connections. -An introduction to zone-based firewalls can be found `here -`_, -and an example at :ref:`examples-zone-policy`. Groups ------ @@ -38,34 +145,68 @@ Groups Firewall groups represent collections of IP addresses, networks, or ports. Once created, a group can be referenced by firewall rules as either a source or destination. Members can be added or removed from a -group without changes to or the need to reload individual firewall +group without changes to, or the need to reload, individual firewall rules. .. note:: Groups can also be referenced by NAT configuration. +Groups need to have unique names. Even though some contain IPv4 +addresses and others contain IPv6 addresses, they still need to have +unique names, so you may want to append "-v4" or "-v6" to your group +names. + + +Address Groups +************** + +In a **address group** a single IP adresses or IP address ranges are +definded. + +.. cfgcmd:: set firewall group address-group address [address | + address range] +.. cfgcmd:: set firewall group ipv6-address-group address
+ + Define a IPv4 or a IPv6 address group + + .. code-block:: none + + set firewall group address-group ADR-INSIDE-v4 address 192.168.0.1 + set firewall group address-group ADR-INSIDE-v4 address 10.0.0.1-10.0.0.8 + set firewall group ipv6-address-group ADR-INSIDE-v6 address 2001:db8::1 + +.. cfgcmd:: set firewall group address-group description +.. cfgcmd:: set firewall group ipv6-address-group description + + Provide a IPv4 or IPv6 address group description + + +Network Groups +************** + While **network groups** accept IP networks in CIDR notation, specific IP addresses can be added as a 32-bit prefix. If you foresee the need to add a mix of addresses and networks, the network group is recommended. -Here is an example of a network group for the IP networks that make up -the internal network: +.. cfgcmd:: set firewall group network-group network +.. cfgcmd:: set firewall group ipv6-network-group network -.. code-block:: none + Define a IPv4 or IPv6 Network group. - set firewall group network-group NET-INSIDE network 192.168.0.0/24 - set firewall group network-group NET-INSIDE network 192.168.1.0/24 + .. code-block:: none -Groups need to have unique names. Even though some contain IPv4 -addresses and others contain IPv6 addresses, they still need to have -unique names, so you may want to append "-v4" or "-v6" to your group -names. + set firewall group network-group NET-INSIDE-v4 network 192.168.0.0/24 + set firewall group network-group NET-INSIDE-v4 network 192.168.1.0/24 + set firewall group ipv6-network-group NET-INSIDE-v6 network 2001:db8::/64 -.. code-block:: none +.. cfgcmd:: set firewall group network-group description +.. cfgcmd:: set firewall group ipv6-network-group description - set firewall group network-group NET-INSIDE-v4 network 192.168.1.0/24 - set firewall group ipv6-network-group NET-INSIDE-v6 network 2001:db8::/64 + Provide a IPv4 or IPv6 network group description. + +Port Groups +*********** A **port group** represents only port numbers, not the protocol. Port groups can be referenced for either TCP or UDP. It is recommended that @@ -73,86 +214,487 @@ TCP and UDP groups are created separately to avoid accidentally filtering unnecessary ports. Ranges of ports can be specified by using `-`. -Here is an example of a port group a server: +.. cfgcmd:: set firewall group port-group port + [portname | portnumber | startport-endport] -.. code-block:: none + Define a port group. A port name are any name defined in + /etc/services. e.g.: http + + .. code-block:: none + + set firewall group port-group PORT-TCP-SERVER1 port http + set firewall group port-group PORT-TCP-SERVER1 port 443 + set firewall group port-group PORT-TCP-SERVER1 port 5000-5010 + +.. cfgcmd:: set firewall group port-group description + + Provide a port group description. - set firewall group port-group PORT-TCP-SERVER1 port 80 - set firewall group port-group PORT-TCP-SERVER1 port 443 - set firewall group port-group PORT-TCP-SERVER1 port 5000-5010 Rule-Sets ---------- +---------- A rule-set is a named collection of firewall rules that can be applied to an interface or zone. Each rule is numbered, has an action to apply if the rule is matched, and the ability to specify the criteria to -match. +match. Data packets go through the rules from 1 - 9999, at the first match +the action of the rule will executed. -Example of a rule-set to filter traffic to the internal network: +.. cfgcmd:: set firewall name description +.. cfgcmd:: set firewall ipv6-name description -.. code-block:: none + Provide a rule-set description. + +.. cfgcmd:: set firewall name default-action [drop | reject | accept] +.. cfgcmd:: set firewall ipv6-name default-action [drop | reject | + accept] + + This set the default action of the rule-set if no rule matched a paket + criteria. + +.. cfgcmd:: set firewall name enable-default-log +.. cfgcmd:: set firewall ipv6-name enable-default-log + + Use this command to enable the logging of the default action. + +.. cfgcmd:: set firewall name rule <1-9999> action [drop | reject | + accept] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> action [drop | reject | + accept] + + This required setting define the action of the current rule. + +.. cfgcmd:: set firewall name rule <1-9999> description +.. cfgcmd:: set firewall ipv6-name rule <1-9999> description + + Provide a description for each rule. + +.. cfgcmd:: set firewall name rule <1-9999> log [disable | enable] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> log [disable | enable] + + Enable or disable logging for the matched packet. + +.. cfgcmd:: set firewall name rule <1-9999> disable +.. cfgcmd:: set firewall ipv6-name rule <1-9999> disable + + If you want to disable a rule but let it in the configuration. + +Matching criteria +***************** + +There are a lot of matching criteria gainst which the package can be tested. + + +.. cfgcmd:: set firewall name rule <1-9999> source address + [address | addressrange | CIDR] +.. cfgcmd:: set firewall name rule <1-9999> destination address + [address | addressrange | CIDR] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source address + [address | addressrange | CIDR] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> destination address + [address | addressrange | CIDR] + + This is similiar to the network groups part, but here you are able to negate + the matching addresses. + + .. code-block:: none + + set firewall name WAN-IN-v4 rule 100 source address 192.0.2.10-192.0.2.11 + # with a '!' the rule match everything except the specified subnet + set fitewall name WAN-IN-v4 rule 101 source address !203.0.113.0/24 + set firewall ipv6-name WAN-IN-v6 rule 100 source address 2001:db8::202 + + +.. cfgcmd:: set firewall name rule <1-9999> source mac-address + +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source mac-address + + + Only in the source criteria you can specify a mac-address + + .. code-block:: none + + set firewall name LAN-IN-v4 rule 100 source mac-address 00:53:00:11:22:33 + set firewall name LAN-IN-v4 rule 101 source mac-address !00:53:00:aa:12:34 + +.. cfgcmd:: set firewall name rule <1-9999> source port + [1-65535 | portname | start-end] +.. cfgcmd:: set firewall name rule <1-9999> destination port + [1-65535 | portname | start-end] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source port + [1-65535 | portname | start-end] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> destination port + [1-65535 | portname | start-end] + + A port can be set with a portnumber or a name which is here + defined: ``/etc/services``. + + .. code-block:: none + + set firewall name WAN-IN-v4 rule 10 source port '22' + set firewall name WAN-IN-v4 rule 11 source port '!http' + set firewall name WAN-IN-v4 rule 12 source port 'https' + + Multiple source ports can be specified as a comma-separated list. + The whole list can also be "negated" using '!'. For example: + + .. code-block:: none + + set firewall ipv6-name WAN-IN-v6 rule 10 source port '!22,https,3333-3338' + +.. cfgcmd:: set firewall name rule <1-9999> source group + address-group +.. cfgcmd:: set firewall name rule <1-9999> destination group + address-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source group + address-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> destination group + address-group + + Use a specific address-group + +.. cfgcmd:: set firewall name rule <1-9999> source group + network-group +.. cfgcmd:: set firewall name rule <1-9999> destination group + network-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source group + network-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> destination group + network-group + + Use a specific network-group + +.. cfgcmd:: set firewall name rule <1-9999> source group + port-group +.. cfgcmd:: set firewall name rule <1-9999> destination group + port-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> source group + port-group +.. cfgcmd:: set firewall ipv6-name rule <1-9999> destination group + port-group + + Use a specific port-group + +.. cfgcmd:: set firewall name rule <1-9999> protocol [ | + <0-255> | all | tcp_udp] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> protocol [ | + <0-255> | all | tcp_udp] + + Match a protocol criteria. A protocol number or a name which is here + defined: ``/etc/protocols``. + Special names are ``all`` for all protocols and ``tcp_udp`` for tcp and upd + based pakets. The ``!`` negate the selected protocol. + + .. code-block:: none + + set firewall name WAN-IN-v4 rule 10 protocol tcp_udp + set firewall name WAN-IN-v4 rule 11 protocol !tcp_udp + set firewall ipv6-name WAN-IN-v6 rule 10 protocol tcp + +.. cfgcmd:: set firewall name rule <1-9999> tcp flags +.. cfgcmd:: set firewall ipv6-name rule <1-9999> tcp flags + + Allowed values fpr TCP flags: ``SYN``, ``ACK``, ``FIN``, ``RST``, ``URG``, + ``PSH``, ``ALL`` When specifying more than one flag, flags should be comma + separated. The ``!`` negate the selected protocol. + + .. code-block:: none + + set firewall name WAN-IN-v4 rule 10 tcp flags 'ACK' + set firewall name WAN-IN-v4 rule 12 tcp flags 'SYN' + set firewall name WAN-IN-v4 rule 13 tcp flags 'SYN,!ACK,!FIN,!RST' + +.. cfgcmd:: set firewall name rule <1-9999> state [established | + invalid | new | releated] +.. cfgcmd:: set firewall ipv6-name rule <1-9999> state [established | + invalid | new | releated] + + Match against the state of a packet. - set firewall name INSIDE-OUT default-action drop - set firewall name INSIDE-OUT rule 1010 action accept - set firewall name INSIDE-OUT rule 1010 state established enable - set firewall name INSIDE-OUT rule 1010 state related enable - set firewall name INSIDE-OUT rule 1020 action drop - set firewall name INSIDE-OUT rule 1020 state invalid enable Applying a Rule-Set to an Interface ----------------------------------- -Once a rule-set is created, it can be applied to an interface. +A Rule-Set can be appliend to every inteface: -.. note:: Only one rule-set can be applied to each interface for `in`, - `out`, or `local` traffic for each protocol (IPv4 and IPv6). +* ``in``: Ruleset for forwarded packets on inbound interface +* ``out``: Ruleset for forwarded packets on outbound interface +* ``local``: Ruleset for packets destined for this router -.. code-block:: none +.. cfgcmd:: set interface ethernet firewall [in | out | local] + [name | ipv6-name] + + Here are some examples for applying a rule-set to an interface + + .. code-block:: none + + set interface ethernet eth1 vif 100 firewall in name LANv4-IN + set interface ethernet eth1 vif 100 firewall out name LANv4-OUT + set interface bonding bond0 firewall in name LANv4-IN + set interfaces openvpn vtun1 firewall in name Lanv4-IN + + .. note:: + As you can see in the example here, you can assign the same rule-set to + several interfaces. An interface can only have one rule-set per chain. + + +Zone-based Firewall Policy +-------------------------- + +As an alternative to applying policy to an interface directly, a +zone-based firewall can be created to simplify configuration when +multiple interfaces belong to the same security zone. Instead of +applying rulesets to interfaces, they are applied to source +zone-destination zone pairs. + +An basic introduction to zone-based firewalls can be found `here +`_, +and an example at :ref:`examples-zone-policy`. + +Define a Zone +************* + +To define a zone setup either one with interfaces or a local zone. + +.. cfgcmd:: set zone-policy zone interface + + Set a interfaces to a zone. A zone can have multiple interfaces. + But a interface can only be member in one zone. + +.. cfgcmd:: set zone-policy zone local-zone + + Define the Zone as a local zone. A local zone have no interfaces and + will be applied to the router itself. + +.. cfgcmd:: set zone-policy zone default-action [drop | reject] + + Change the default-action with this setting. + +.. cfgcmd:: set zone-policy zone description + + Set a meaningful description. - set interfaces ethernet eth1 firewall out name INSIDE-OUT Applying a Rule-Set to a Zone ------------------------------ +***************************** -A named rule-set can also be applied to a zone relationship (note, zones must -first be created): +Before you are able to apply a rule-set to a zone you have to create the zones +first. -.. code-block:: none +.. cfgcmd:: set zone-policy zone from firewall name + +.. cfgcmd:: set zone-policy zone from firewall ipv6-name + - set zone-policy zone INSIDE from OUTSIDE firewall name INSIDE-OUT + You apply a rule-set always to a zone from a other zone, it is recommended + to create one rule-set for each zone pair. -How VyOS replies when being pinged ----------------------------------- + .. code-block:: none -By default, when VyOS receives an ICMP echo request packet destined for -itself, it will answer with an ICMP echo reply, unless you avoid it -through its firewall. + set zone-policy zone DMZ from LAN firewall name LANv4-to-DMZv4 + set zone-policy zone LAN from DMZ firewall name DMZv4-to-LANv4 -With the firewall you can set rules to accept, drop or reject ICMP in, -out or local traffic. You can also use the general **firewall all-ping** -command. This command affects only to LOCAL (packets destined for your -VyOS system), not to IN or OUT traffic. -.. note:: **firewall all-ping** affects only to LOCAL and it always - behaves in the most restrictive way +Operation-mode Firewall +----------------------- -.. code-block:: none +Rule-set overview +***************** - set firewall all-ping enable +.. opcmd:: show firewall -When the command above is set, VyOS will answer every ICMP echo request -addressed to itself, but that will only happen if no other rule is -applied dropping or rejecting local echo requests. In case of conflict, -VyOS will not answer ICMP echo requests. + This will show you a basic firewall overview -.. code-block:: none + .. code-block:: none + + vyos@vyos:~$ show firewall + + ------------------------ + Firewall Global Settings + ------------------------ + + Firewall state-policy for all IPv4 and Ipv6 traffic + + state action log + ----- ------ --- + invalid accept disabled + established accept disabled + related accept disabled + + ----------------------------- + Rulesets Information + ----------------------------- + -------------------------------------------------------------------------- + IPv4 Firewall "DMZv4-1-IN": + + Active on (eth0,IN) + + rule action proto packets bytes + ---- ------ ----- ------- ----- + 10 accept icmp 0 0 + condition - saddr 10.1.0.0/24 daddr 0.0.0.0/0 LOG enabled + + 10000 drop all 0 0 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 LOG enabled + + -------------------------------------------------------------------------- + IPv4 Firewall "DMZv4-1-OUT": + + Active on (eth0,OUT) + + rule action proto packets bytes + ---- ------ ----- ------- ----- + 10 accept tcp_udp 1 60 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 match-DST-PORT-GROUP DMZ-Ports /* + DMZv4-1-OUT-10 */LOG enabled + + 11 accept icmp 1 84 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 /* DMZv4-1-OUT-11 */LOG enabled + + 10000 drop all 6 360 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 LOG enabled + + -------------------------------------------------------------------------- + IPv4 Firewall "LANv4-IN": + + Inactive - Not applied to any interfaces or zones. + + rule action proto packets bytes + ---- ------ ----- ------- ----- + 10 accept all 0 0 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 /* LANv4-IN-10 */ + + 10000 drop all 0 0 + condition - saddr 0.0.0.0/0 daddr 0.0.0.0/0 + +.. opcmd:: show firewall summary + + This will show you a summary about rule-sets and groups + + .. code-block:: + + vyos@vyos:~$ show firewall summary + + ------------------------ + Firewall Global Settings + ------------------------ + + Firewall state-policy for all IPv4 and Ipv6 traffic + + state action log + ----- ------ --- + invalid accept disabled + related accept disabled + established accept disabled + + ------------------------ + Firewall Rulesets + ------------------------ + + IPv4 name: + + Rule-set name Description References + ------------- ----------- ---------- + DMZv4-1-OUT (eth0,OUT) + DMZv4-1-IN (eth0,IN) + + ------------------------ + Firewall Groups + ------------------------ + + Port Groups: + + Group name Description References + ---------- ----------- ---------- + DMZ-Ports DMZv4-1-OUT-10-destination + + Network Groups: + + Group name Description References + ---------- ----------- ---------- + LANv4 LANv4-IN-10-source, + DMZv4-1-OUT-10-source, + DMZv4-1-OUT-11-source + +.. opcmd:: show firewall statistics + + This will show you a statistic of all rule-sets since the last boot. + +.. opcmd:: show firewall [name | ipv6name] rule <1-9999> + + This command will give an overview about a rule in a single rule-set + +.. opcmd:: show firewall group + + Overview of defined groups. You see the type, the members, and where the + group is used. + + .. code-block:: none + + vyos@vyos:~$ show firewall group DMZ-Ports + Name : DMZ-Ports + Type : port + References : none + Members : + 80 + 443 + 8080 + 8443 + + vyos@vyos:~$ show firewall group LANv4 + Name : LANv4 + Type : network + References : LANv4-IN-10-source + Members : + 10.10.0.0/16 + +.. opcmd:: show firewall [name | ipv6name] + + This command will give an overview about a single rule-set + +.. opcmd:: show firewall [name | ipv6name] statistics + + This will show you a rule-set statistic since the last boot. + +.. opcmd:: show firewall [name | ipv6name] rule <1-9999> + + This command will give an overview about a rule in a single rule-set + + +Zone-Policy Overview +******************** + +.. opcmd:: show zone-policy zone + + Use this command to get an overview about a zone + + .. code-block:: none + + vyos@vyos:~$ show zone-policy zone DMZ + ------------------- + Name: DMZ + + Interfaces: eth0 eth1 + + From Zone: + name firewall + ---- -------- + LAN DMZv4-1-OUT + + +Show Firewall log +***************** + +.. opcmd:: show log firewall [name | ipv6name] + + Show the logs of a specific Rule-Set + +.. note:: + At the moment it not possible to look at the hole Firewall log with vyos + operational commands. All logs will save to ``/var/logs/messages``. + For example: ``grep '10.10.0.10' /var/log/messages`` - set firewall all-ping disable -When the command above is set, VyOS will answer no ICMP echo request -addressed to itself at all, no matter where it comes from or whether -more specific rules are being applied to accept them. Example Partial Config ---------------------- -- cgit v1.2.3