Provided by: spamassassin_3.4.2-0ubuntu0.14.04.1_all bug

NAME

       URIDNSBL - look up URLs against DNS blocklists

SYNOPSIS

         loadplugin    Mail::SpamAssassin::Plugin::URIDNSBL
         uridnsbl      URIBL_SBLXBL    sbl-xbl.spamhaus.org.   TXT

DESCRIPTION

       This works by analysing message text and HTML for URLs, extracting host names from those,
       then querying various DNS blocklists for either: IP addresses of these hosts (uridnsbl,a)
       or their nameservers (uridnsbl,ns), or domain names of these hosts (urirhsbl), or domain
       names of their nameservers (urinsrhsbl, urifullnsrhsbl).

USER SETTINGS

       skip_uribl_checks ( 0 | 1 )   (default: 0)
           Turning on the skip_uribl_checks setting will disable the URIDNSBL plugin.

           By default, SpamAssassin will run URI DNSBL checks. Individual URI blocklists may be
           disabled selectively by setting a score of a corresponding rule to 0 or through the
           uridnsbl_skip_domain parameter.

           See also a related configuration parameter skip_rbl_checks, which controls the DNSEval
           plugin (documented in the Conf man page).

       uridnsbl_skip_domain domain1 domain2 ...
           Specify a domain, or a number of domains, which should be skipped for the URIBL
           checks.  This is very useful to specify very common domains which are not going to be
           listed in URIBLs.

       clear_uridnsbl_skip_domain [domain1 domain2 ...]
           If no argument is given, then clears the entire list of domains declared by
           uridnsbl_skip_domain configuration directives so far. Any subsequent
           uridnsbl_skip_domain directives will start creating a new list of skip domains.

           When given a list of domains as arguments, only the specified domains are removed from
           the list of skipped domains.

RULE DEFINITIONS AND PRIVILEGED SETTINGS

       uridnsbl NAME_OF_RULE dnsbl_zone lookuptype
           Specify a lookup.  "NAME_OF_RULE" is the name of the rule to be used, "dnsbl_zone" is
           the zone to look up IPs in, and "lookuptype" is the type of lookup (TXT or A).   Note
           that you must also define a body-eval rule calling "check_uridnsbl()" to use this.

           This works by collecting domain names from URLs and querying DNS blocklists with an IP
           address of host names found in URLs or with IP addresses of their name servers,
           according to tflags as follows.

           If the corresponding body rule has a tflag 'a', the DNS blocklist will be queried with
           an IP address of a host found in URLs.

           If the corresponding body rule has a tflag 'ns', DNS will be queried for name servers
           (NS records) of a domain name found in URLs, then these name server names will be
           resolved to their IP addresses, which in turn will be sent to DNS blocklist.

           Tflags directive may specify either 'a' or 'ns' or both flags. In absence of any of
           these two flags, a default is a 'ns', which is compatible with pre-3.4 versions of
           SpamAssassin.

           The choice of tflags must correspond to the policy and expected use of each DNS
           blocklist and is normally not a local decision. As an example, a blocklist expecting
           queries resulting from an 'a' tflag is a "black_a.txt" (
           http://www.uribl.com/datasets.shtml ).

           Example:

            uridnsbl        URIBL_SBLXBL    sbl-xbl.spamhaus.org.   TXT
            body            URIBL_SBLXBL    eval:check_uridnsbl('URIBL_SBLXBL')
            describe        URIBL_SBLXBL    Contains a URL listed in the SBL/XBL blocklist
            tflags          URIBL_SBLXBL    net ns

       uridnssub NAME_OF_RULE dnsbl_zone lookuptype subtest
           Specify a DNSBL-style domain lookup with a sub-test.  "NAME_OF_RULE" is the name of
           the rule to be used, "dnsbl_zone" is the zone to look up IPs in, and "lookuptype" is
           the type of lookup (TXT or A).

           Tflags 'ns' and 'a' on a corresponding body rule are recognized and have the same
           meaning as in the uridnsbl directive.

           "subtest" is a sub-test to run against the returned data.  The sub-test may be in one
           of the following forms: m, n1-n2, or n/m, where n,n1,n2,m can be any of: decimal
           digits, 0x followed by up to 8 hexadecimal digits, or an IPv4 address in quad-dot
           form. The 'A' records (IPv4 dotted address) as returned by DNSBLs lookups are
           converted into a numerical form (r) and checked against the specified sub-test as
           follows: for a range n1-n2 the following must be true: (r >= n1 && r <= n2); for a n/m
           form the following must be true: (r & m) == (n & m); for a single value in quad-dot
           form the following must be true: r == n; for a single decimal or hex form the
           following must be true:
             ((r & n) != 0) && ((r & 0xff000000) == 0x7f000000), i.e. within 127.0.0.0/8

           Some typical examples of a sub-test are: 127.0.1.2, 127.0.1.20-127.0.1.39,
           127.0.1.0/255.255.255.0, 0.0.0.16/0.0.0.16, 0x10/0x10, 16, 0x10 .

           Note that, as with "uridnsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

           Example:

             uridnssub   URIBL_DNSBL_4    dnsbl.example.org.   A    127.0.0.4
             uridnssub   URIBL_DNSBL_8    dnsbl.example.org.   A    8

       urirhsbl NAME_OF_RULE rhsbl_zone lookuptype
           Specify a RHSBL-style domain lookup.  "NAME_OF_RULE" is the name of the rule to be
           used, "rhsbl_zone" is the zone to look up domain names in, and "lookuptype" is the
           type of lookup (TXT or A).   Note that you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

           An RHSBL zone is one where the domain name is looked up, as a string; e.g. a URI using
           the domain "foo.com" will cause a lookup of "foo.com.uriblzone.net".  Note that
           hostnames are stripped from the domain used in the URIBL lookup, so the domain
           "foo.bar.com" will look up "bar.com.uriblzone.net", and "foo.bar.co.uk" will look up
           "bar.co.uk.uriblzone.net".

           If an URI consists of an IP address instead of a hostname, the IP address is looked up
           (using the standard reversed quads method) in each "rhsbl_zone".

           Example:

             urirhsbl        URIBL_RHSBL    rhsbl.example.org.   TXT

       urirhssub NAME_OF_RULE rhsbl_zone lookuptype subtest
           Specify a RHSBL-style domain lookup with a sub-test.  "NAME_OF_RULE" is the name of
           the rule to be used, "rhsbl_zone" is the zone to look up domain names in, and
           "lookuptype" is the type of lookup (TXT or A).

           "subtest" is a sub-test to run against the returned data.  The sub-test may be in one
           of the following forms: m, n1-n2, or n/m, where n,n1,n2,m can be any of: decimal
           digits, 0x followed by up to 8 hexadecimal digits, or an IPv4 address in quad-dot
           form. The 'A' records (IPv4 dotted address) as returned by DNSBLs lookups are
           converted into a numerical form (r) and checked against the specified sub-test as
           follows: for a range n1-n2 the following must be true: (r >= n1 && r <= n2); for a n/m
           form the following must be true: (r & m) == (n & m); for a single value in quad-dot
           form the following must be true: r == n; for a single decimal or hex form the
           following must be true:
             ((r & n) != 0) && ((r & 0xff000000) == 0x7f000000), i.e. within 127.0.0.0/8

           Some typical examples of a sub-test are: 127.0.1.2, 127.0.1.20-127.0.1.39,
           127.2.3.0/255.255.255.0, 0.0.0.16/0.0.0.16, 0x10/0x10, 16, 0x10 .

           Note that, as with "urirhsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

           Example:

             urirhssub   URIBL_RHSBL_4    rhsbl.example.org.   A    127.0.0.4
             urirhssub   URIBL_RHSBL_8    rhsbl.example.org.   A    8

       urinsrhsbl NAME_OF_RULE rhsbl_zone lookuptype
           Perform a RHSBL-style domain lookup against the contents of the NS records for each
           URI.  In other words, a URI using the domain "foo.com" will cause an NS lookup to take
           place; assuming that domain has an NS of "ns0.bar.com", that will cause a lookup of
           "bar.com.uriblzone.net".  Note that hostnames are stripped from both the domain used
           in the URI, and the domain in the lookup.

           "NAME_OF_RULE" is the name of the rule to be used, "rhsbl_zone" is the zone to look up
           domain names in, and "lookuptype" is the type of lookup (TXT or A).

           Note that, as with "urirhsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

       urinsrhssub NAME_OF_RULE rhsbl_zone lookuptype subtest
           Specify a RHSBL-style domain-NS lookup, as above, with a sub-test.  "NAME_OF_RULE" is
           the name of the rule to be used, "rhsbl_zone" is the zone to look up domain names in,
           and "lookuptype" is the type of lookup (TXT or A).  "subtest" is the sub-test to run
           against the returned data; see <urirhssub>.

           Note that, as with "urirhsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

       urifullnsrhsbl NAME_OF_RULE rhsbl_zone lookuptype
           Perform a RHSBL-style domain lookup against the contents of the NS records for each
           URI.  In other words, a URI using the domain "foo.com" will cause an NS lookup to take
           place; assuming that domain has an NS of "ns0.bar.com", that will cause a lookup of
           "ns0.bar.com.uriblzone.net".  Note that hostnames are stripped from the domain used in
           the URI.

           "NAME_OF_RULE" is the name of the rule to be used, "rhsbl_zone" is the zone to look up
           domain names in, and "lookuptype" is the type of lookup (TXT or A).

           Note that, as with "urirhsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

       urifullnsrhssub NAME_OF_RULE rhsbl_zone lookuptype subtest
           Specify a RHSBL-style domain-NS lookup, as above, with a sub-test.  "NAME_OF_RULE" is
           the name of the rule to be used, "rhsbl_zone" is the zone to look up domain names in,
           and "lookuptype" is the type of lookup (TXT or A).  "subtest" is the sub-test to run
           against the returned data; see <urirhssub>.

           Note that, as with "urirhsbl", you must also define a body-eval rule calling
           "check_uridnsbl()" to use this.

       tflags NAME_OF_RULE ips_only
           Only URIs containing IP addresses as the "host" component will be matched against the
           named "urirhsbl"/"urirhssub" rule.

       tflags NAME_OF_RULE domains_only
           Only URIs containing a non-IP-address "host" component will be matched against the
           named "urirhsbl"/"urirhssub" rule.

       tflags NAME_OF_RULE ns
           The 'ns' flag may be applied to rules corresponding to uridnsbl and uridnssub
           directives. Host names from URLs will be mapped to their name server IP addresses (a
           NS lookup followed by an A lookup), which in turn will be sent to blocklists. This is
           a default when neither 'a' nor 'ns' flags are specified.

       tflags NAME_OF_RULE a
           The 'a' flag may be applied to rules corresponding to uridnsbl and uridnssub
           directives. Host names from URLs will be mapped to their IP addresses, which will be
           sent to blocklists. When both 'ns' and 'a' flags are specified, both queries will be
           performed.

ADMINISTRATOR SETTINGS

       uridnsbl_max_domains N        (default: 20)
           The maximum number of domains to look up.

NOTES

       The "uridnsbl_timeout" option has been obsoleted by the "rbl_timeout" option.  See the
       "Mail::SpamAssassin::Conf" POD for details on "rbl_timeout".