NAME

Net::Firewall::BlockerHelper::backends::fastly - Fastly Edge ACL backend for Net::Firewall::BlockerHelper.

VERSION

Version 0.1.0

SYNOPSIS

use Net::Firewall::BlockerHelper;

my $fw_helper = Net::Firewall::BlockerHelper->new(
    backend => 'fastly',
    name    => 'ssh',
    options => {
        token   => $fastly_api_token,
        service => $fastly_service_id,
        acl     => $fastly_acl_id,
    },
);

$fw_helper->init_backend;
$fw_helper->ban( ban => '1.2.3.4' );
$fw_helper->unban( ban => '1.2.3.4' );

DESCRIPTION

Blocks IPs remotely via the Fastly API by adding and removing entries in an Edge ACL. An ACL entry is created per IP, with a /32 subnet for IPv4 and a /128 subnet for IPv6. A VCL service that references the ACL and takes action on matching requests must already exist.

Auth is via a Fastly API token, passed in the token option and sent in the Fastly-Key header.

Blocking is per IP; ports and protocols are not supported and specifying them is an error.

LWP::UserAgent is only loaded at run time, so it is only required if this backend is actually used. For https, LWP::Protocol::https must be present as well.

NOTES

This backend was written going off the API docs and actual testing is needed to double check a few things as the exact behavior is not clear.

teardown currently only removes the single IP entries from the ACL, leaving CIDR entries in place, while flush removes both. A re_init after a teardown will re-add the CIDR entries, and how the API handles creating an entry that already exists needs checking.

METHODS

new

Initiates the the object.

- options :: Backend specific options. See below.
    - Default :: {}

- prefix :: Prefix to use. Must match the regex /^[a-zA-Z0-9]+$/
    - default :: kur

- name :: Name of this specific instance. This must be specified.
    - default :: undef

Ports and protocols are not supported by this backend and specifying either is an error.

The options hash accepts the following.

- token :: Fastly API token, sent in the Fastly-Key header.
    - Default :: undef

- service :: Fastly service ID the ACL belongs to.
    - Default :: undef

- acl :: Fastly Edge ACL ID to manage entries under.
    - Default :: undef

- timeout :: HTTP timeout in seconds.
    - Default :: 30

- insecure :: If true, skip TLS certificate verification.
    - Default :: 0

All errors are considered fatal, meaning if new fails it will die.

init

Initiates the backend. Verifies the credentials and endpoint by fetching a single ACL entry.

$backend->init;

ban

Bans an IP. The value of ban is validated as being a IPv4 or IPv6 address and lowercased, then an ACL entry is created for it via a POST, with a /32 subnet for IPv4 and a /128 subnet for IPv6. Banning an already banned IP is a noop.

$backend->ban(ban => $ip);

unban

Unbans an IP. The value of ban is validated as being a IPv4 or IPv6 address and lowercased, then the ACL entries are fetched, the entry for the IP is found, and it is deleted by its ID. An entry that can not be found is treated as already unbanned. Unbanning an IP that is not banned is a noop.

$backend->unban(ban => $ip);

list

List banned IPs. Returns an array of the currently banned single IPs. CIDR ranges are not included; for those see "list_cidr".

my @banned = $backend->list;

ban_cidr

Bans a CIDR range by creating an ACL entry for it. The range is split into its address and prefix length, sent as the ACL entry's ip and subnet, mirroring how a single IP is banned as a /32 or /128 entry. The value of ban is validated as being a IPv4 or IPv6 CIDR range and lowercased. Banning an already banned range is a noop.

$backend->ban_cidr(ban => '1.2.3.0/24');

unban_cidr

Unbans a CIDR range. The value of ban is validated as being a IPv4 or IPv6 CIDR range and lowercased, then the ACL entries are fetched, the entry matching its address and prefix length is found, and it is deleted by its ID. An entry that can not be found is treated as already unbanned. Unbanning a range that is not banned is a noop.

$backend->unban_cidr(ban => '1.2.3.0/24');

list_cidr

List banned CIDR ranges. Returns an array of the currently banned CIDR ranges. Single IPs are not included; for those see "list".

my @banned_cidrs = $backend->list_cidr;

re_init

Tells the backend to re-init it's self.

This will call teardown and init again. After that it will re-add all previously added bans, POSTing an ACL entry for each retained IP and CIDR range.

$backend->re_init;

teardown

Tears down the setup for the backend by removing the ACL entry for each currently banned IP. The internal list of bans is kept, so a following re_init will re-add them.

$backend->teardown;

stop

Alias for "teardown", provided for parity with the fail2ban actionstop concept.

$backend->stop;

check

Verifies the endpoint and credentials are still usable by fetching a single ACL entry. Returns a true value if so and a false value otherwise. This is the equivalent of fail2ban's actioncheck.

if ( !$backend->check ) {
    $backend->re_init;
}

flush

Removes all currently banned IPs at once by removing their ACL entries and forgetting them. This is the equivalent of fail2ban's actionflush.

$backend->flush;

ERROR CODES / FLAGS

Error handling is provided by Error::Helper. All errors are considered fatal.

1, notInited

The backend has not been inited yet.

6, invalidPrefixSpecified

The specified prefix did not match /^[a-zA-Z0-9]+$/.

7, invalidName

The name is either undef or does not match /^[a-zA-Z0-9\-]+$/.

8, optionsNotHash

The item passed to new for options is not a hash.

9, noBanItem

No IP or CIDR range specified to ban or unban.

10, banItemNotIP

The item to ban is not an IP. Either wrong ref type or regexp test using Regexp::IPv4 and Regexp::IPv6 failed.

12, backendInitError

Failed to init the backend.

13, banFailed

Failed to ban the item.

14, unbanFailed

Failed to unban the item.

15, listFailed

Failed to get a list of bans.

16, reInitFailed

Failed to re_init the backend.

17, teardownFailed

Failed to teardown the backend.

18, alreadyInited

init called, but the backend has already been inited.

23, initFailed

Init failed. Probing the ACL entries endpoint failed.

24, checkFailed

The backend check raised an error.

25, flushFailed

Failed to flush the bans.

26, portsNotSupported

The fastly backend blocks whole IPs and does not support ports.

27, protocolsNotSupported

The fastly backend blocks whole IPs and does not support protocols.

30, serviceNotDefined

The option service is undef or blank.

31, tokenNotDefined

The option token is undef or blank.

32, aclNotDefined

The option acl is undef or blank.

33, banCidrFailed

Failed to ban the CIDR range.

34, unbanCidrFailed

Failed to unban the CIDR range.

35, cidrItemNotCidr

The item to ban is not a CIDR range. Either wrong ref type or it is not an IPv4 or IPv6 address followed by a prefix length valid for its family.

36, cidrNotSupported

The backend does not support CIDR bans.

37, listCidrFailed

Failed to get a list of CIDR bans.

AUTHOR

Zane C. Bowers-Hadley, <vvelox at vvelox.ent>

BUGS

Please report any bugs or feature requests to bug-net-firewall-blockerhelper at rt.cpan.org, or through the web interface at https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Net-Firewall-BlockerHelper.

LICENSE AND COPYRIGHT

This software is Copyright (c) 2023 by Zane C. Bowers-Hadley.

This is free software, licensed under:

The GNU Lesser General Public License, Version 2.1, February 1999