spfd.mail-spf-perl(8p)
NAME
spfd - (Mail::SPF) - Simple forking daemon to provide SPF query services
VERSION
2.000
SYNOPSIS
spfd --port|-p port [--set-user|-u uid|username] [--set-group|-g gid|groupname] [OPTIONS] spfd --socket|-s filename [--socket-user uid|username] [--socket-group gid|groupname] [--socket-perms octal-perms] [--set-user|-u uid|username] [--set-group|-g gid|groupname] [OPTIONS] spfd --version|-V spfd --help
DESCRIPTION
spfd is a simple forking Sender Policy Framework (SPF) query server. spfd receives and answers SPF requests on a TCP/IP or UNIX domain socket. For more information on SPF see <http://www.openspf.org>. The --port form listens on a TCP/IP socket on the specified port. The default port is 5970. The --socket form listens on a UNIX domain socket that is created with the specified filename. The socket can be assigned specific user and group ownership with the --socket-user and --socket-group options, and specific filesystem permissions with the --socket-perms option. Generally, spfd can be instructed with the --set-user and --set-group options to drop root privileges and change to another user and group before it starts listening for requests. The --version form prints version information of spfd. The --help form prints usage information for spfd.
OPTIONS
spfd takes any of the following OPTIONS:
--default-explanation string
--def-exp string
Use the specified string as the default explanation if the
authority domain does not specify an explanation string of its own.
--hostname hostname
Use hostname as the host name of the local system instead of auto-
detecting it.
--debug
Print out debug information about spfd's operation, incoming
requests, and the responses sent.
REQUEST
A request consists of a series of lines delimited by \x0A (LF)
characters (or whatever your system considers a newline). Each line
must be of the form option=value, where the following options are
supported:
versions
A comma-separated list of SPF version numbers of SPF records that
may be used. 1 means that "v=spf1" records should be used. 2
means that "spf2.0" records should be used. Defaults to 1,2, i.e.,
uses any SPF records that are available. Records of a higher
version are preferred.
scope
The authorization scope of the identity that should be checked.
Defaults to 'mfrom'. The following scope values are supported:
'helo', 'mfrom', 'pra'. See "new" in Mail::SPF::Request for more
information.
identity
Required. The sender identity whose authorization should be
checked. This is a domain name for the "helo" scope, and an e-mail
address for the "mfrom" and "pra" scopes.
ip_address
Required for checks with the "helo", "mfrom", and "pra" scopes.
The IP address of the host claiming the identity that is being
checked. Can be either an IPv4 or an IPv6 address. An IPv4-mapped
IPv6 address (e.g. '::ffff:192.168.0.1') is treated as an IPv4
address.
helo_identity
The "HELO" SMTP transaction parameter in the case that the main
identity is of a scope other than "helo". This identity is then
used merely for the expansion of "%{h}" macros during the policy
evaluation of the main identity. If unspecified with a scope other
than "helo", defaults to "unknown". If the main identity is of the
"helo" scope, this option is unused.
RESPONSE
spfd responds to SPF requests with similar series of lines of the form
key=value. The most important response keys are:
result
The result code of the SPF check:
pass The specified IP address is an authorized SMTP sender
for the identity.
fail The specified IP address is not an authorized SMTP
sender for the identity.
softfail The specified IP address is not an authorized SMTP
sender for the identity, however the authority domain
is still testing out its SPF policy.
neutral The identity's authority domain makes no assertion
about the status of the IP address.
permerror A permanent error occurred while evaluating the
authority domain's policy (e.g., a syntax error in the
SPF record). Manual intervention is required from the
authority domain.
temperror A temporary error occurred while evaluating the
authority domain's policy (e.g., a DNS error). Try
again later.
none There is no applicable SPF policy for the identity
domain.
local_explanation
A locally generated explanation of the SPF result.
authority_explanation
The authority domain's explanation for the SPF result. Be aware
that the authority domain may be a malicious party and thus the
authority explanation should not be trusted blindly. See RFC 4408,
10.5, for a detailed discussion of this issue.
received_spf_header
An appropriate "Received-SPF" header field for the SPF result.
spf_record
The authority domain's SPF record that was used for the policy
evaluation.
EXAMPLE
A running spfd could be tested using the "netcat" utility like this
(line breaks added for clarity):
$ echo -e "identity=user@example.com\nip_address=1.2.3.4\n" \
| nc localhost 5970
result=fail
local_explanation=example.com: Sender is not authorized by default to use
'user@example.com' in 'mfrom' identity (mechanism '-all' matched)
authority_explanation=Please see http://www.openspf.org/why.html?
sender=user%40example.com&ip=1.2.3.4&receiver=localhost
received_spf_header=Received-SPF: fail (example.com: Sender is not
authorized by default to use 'user@example.com' in 'mfrom' identity
(mechanism '-all' matched)) receiver=localhost; identity=mfrom;
envelope-from="user@example.com"; client-ip=1.2.3.4
spf_record=v=spf1 mx -all
COMPATIBILITY
spfd has undergone the following interface changes compared to earlier
versions:
2.000
* A new preferred request style has been introduced. Instead of
the old "sender" request option, which is specific to the "MAIL
FROM" SMTP identity, a generic "identity" option should now be
specified. In addition, a "scope" option may be given to
specify the identity's scope, otherwise a scope of "mfrom" is
assumed. The old "ip" and "helo" options have been replaced by
the "ip_address" and "helo_identity" options, respectively.
This is how legacy requests with the "mfrom" scope would
translate to the new preferred request style:
Legacy request style | New request style
----------------------------+---------------------------------------
| scope=mfrom
sender=<mfrom-identity> | identity=<mfrom-identity>
ip=<ip-address> | ip_address=<ip-address>
helo=<helo-identity> | helo_identity=<helo-identity>
A new response style featuring new response values has also
been introduced:
Legacy response style | New response style
----------------------------+---------------------------------------
result=<result-code> | result=<result-code>
header_comment=<local-exp> | local_explanation=<local-exp>
smtp_comment=<local-exp | authority_explanation=<authority-exp>
or authority-exp> |
spf_record=<spf-record> | spf_record=<spf-record>
| received_spf_header=<header>
The legacy request style is deprecated but still supported for
backwards compatibility. The legacy response values are still
returned for backwards compatibility in addition to the new
response values, but may be removed in the future. Adjust your
code to use the new request and response styles.
* The former "unknown" and "error" result codes have been renamed
to "permerror" and "temperror", respectively, in order to
comply with RFC 4408 terminology.
* SPF checks with an empty identity are no longer supported. In
the case of an empty "MAIL FROM" SMTP transaction parameter,
perform a check with the "helo" scope directly.
SEE ALSO
Mail::SPF, spfquery(1) <http://tools.ietf.org/html/rfc4408>
AUTHORS
This version of spfd is a complete rewrite by Julian Mehnle <julian@mehnle.net>, based on an earlier version written by Meng Weng Wong <mengwong+spf@pobox.com>.
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