<b><a name="description">DESCRIPTION</a></b>
<i>NOTE: This service should be enabled only temporarily to generate most</i>
<i>of the non-Berkeley-DB indexed files that Postfix needs. Leaving this</i>
<i>service enabled may expose the system to privilege-escalation attacks.</i>
The <a href="nbdb_reindexd.8.html">nbdb_reindexd(8)</a> server handles requests to generate a non-Berke-
ley-DB indexed database file for an existing Berkeley DB database
(example: "<a href="DATABASE_README.html#types">hash</a>:/path/to/file" or "<a href="DATABASE_README.html#types">btree</a>:/path/to/file"). It implements
the service by running the <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postalias(1)</a> command with
appropriate privileges.
The service reports a success status when the non-Berkeley-DB indexed
file already exists. This can happen when multiple clients make the
same request. When one request is completed successfully, the service
also reports success for the other requests.
This service enforces the following safety policy:
<b>o</b> The legacy Berkeley DB indexed file must exist (file name ends
in ".db"). The <a href="nbdb_reindexd.8.html">nbdb_reindexd(8)</a> service will use the owner"s
(uid, gid) of this file, when it runs <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postal-</a>
<a href="postalias.1.html">ias(1)</a>. It also uses the (uid,gid) for a number of safety checks
as described next.
<b>o</b> The non-indexed source file must exist (file name without ".db"
suffix). This file is needed as input for <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postal-</a>
<a href="postalias.1.html">ias(1)</a>. The file must be owned by "root" or by the above uid,
and must not allow "group" or "other" write access.
<b>o</b> The parent directory must be owned by "root" or by the above
uid, and it must not allow "group" or "other" write access.
<b>o</b> Additionally, the "<a href="postconf.5.html#non_bdb_migration_allow_root_prefixes">non_bdb_migration_allow_root_prefixes</a>"param-
eter limits the source file directory prefixes that are allowed
when this service needs to run <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postalias(1)</a> with "root" privileges.
<b>o</b> A similar parameter, "<a href="postconf.5.html#non_bdb_migration_allow_user_prefixes">non_bdb_migration_allow_user_prefixes</a>",
limits the source file directory prefixes that are allowed when
this service needs to run <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postalias(1)</a> as an
unprivileged user.
<b><a name="security">SECURITY</a></b>
The <a href="nbdb_reindexd.8.html">nbdb_reindexd(8)</a> server is security sensitive. It accepts requests
only from processes that can access sockets under $<a href="postconf.5.html#queue_directory">queue_directory</a>/pri-
vate (i.e., processes that run with "root" or "<a href="postconf.5.html#mail_owner">mail_owner</a>" (usually,
postfix) privileges).
The threat is therefore a corrupted Postfix daemon process that wants
to elevate privileges, by sending requests with crafted pathnames, and
racing against the service by quickly swapping files or directories,
hoping that Postfix will be tricked to overwrite a sensitive file with
attacker-controlled data.
When the service runs <a href="postmap.1.html">postmap(1)</a> or <a href="postalias.1.html">postalias(1)</a> as "root", such racing
attacks should not be possible if <a href="postconf.5.html#non_bdb_migration_allow_root_prefixes">non_bdb_migration_allow_root_prefixes</a>
specifies only prefixes that are already trusted.
This service could block all requests with crafted pathnames, if given
complete information about all lookup tables that are referenced
through Postfix configuration files. Unfortunately that information was
not available at the time that this program was needed.
<b><a name="diagnostics">DIAGNOSTICS</a></b>
Problems and transactions are logged to syslogd(8) or <a href="postlogd.8.html">postlogd(8)</a>. If
an attempt to create an index file fails, this service will attempt to
delete the incomplete file.
<b><a name="configuration_parameters">CONFIGURATION PARAMETERS</a></b>
Changes to <a href="postconf.5.html">main.cf</a> are not picked up automatically, as <a href="nbdb_reindexd.8.html">nbdb_reindexd(8)</a>
processes are long-lived. Use the command"postfix reload" after a con-
figuration change.
The text below provides only a parameter summary. See <a href="postconf.5.html">postconf(5)</a> for
more details including examples.
<b><a name="service-specific_controls">SERVICE-SPECIFIC CONTROLS</a></b>
<b><a href="postconf.5.html#non_bdb_migration_level">non_bdb_migration_level</a> (disable)</b>
The non-Berkeley-DB migration service level.
<b><a href="postconf.5.html#non_bdb_migration_allow_root_prefixes">non_bdb_migration_allow_root_prefixes</a> (see 'postconf -d <a href="postconf.5.html#non_bdb_migration_allow_root_prefixes">non_bdb_migra</a>-</b>
<b><a href="postconf.5.html#non_bdb_migration_allow_root_prefixes">tion_allow_root_prefixes</a>' output)</b>
A list of trusted pathname prefixes that must be matched when
the non-Berkeley-DB migration service (<a href="nbdb_reindexd.8.html"><b>nbdb_reindexd</b>(8)</a>) needs
to run <a href="postmap.1.html"><b>postmap</b>(1)</a> or <a href="postalias.1.html"><b>postalias</b>(1)</a> commands with "root" privi-
lege.
<b><a href="postconf.5.html#non_bdb_migration_allow_user_prefixes">non_bdb_migration_allow_user_prefixes</a> (see 'postconf -d <a href="postconf.5.html#non_bdb_migration_allow_user_prefixes">non_bdb_migra</a>-</b>
<b><a href="postconf.5.html#non_bdb_migration_allow_user_prefixes">tion_allow_user_prefixes</a>' output)</b>
A list of trusted pathname prefixes that must be matched when
the non-Berkeley-DB migration service (<a href="nbdb_reindexd.8.html"><b>nbdb_reindexd</b>(8)</a>) needs
to run <a href="postmap.1.html"><b>postmap</b>(1)</a> or <a href="postalias.1.html"><b>postalias</b>(1)</a> commands with non-root privi-
lege.
<b><a name="miscellaneous_controls">MISCELLANEOUS CONTROLS</a></b>
<b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d'output)</b>
The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> con-
figuration files.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
The process ID of a Postfix command or daemon process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
The process name of a Postfix command or daemon process.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d'output)</b>
A prefix that is prepended to the process name in syslog
records, so that, for example, "smtpd" becomes "prefix/smtpd".
<b><a href="postconf.5.html#service_name">service_name</a> (read-only)</b>
The <a href="master.5.html">master.cf</a> service name of a Postfix daemon process.
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung und die Messung sind noch experimentell.
