Doc: Update ulinks to RFC documents to avoid redirect

The tools.ietf.org site has been decommissioned and replaced by a
number of sites serving various purposes.  Links to RFCs and BCPs
are now 301 redirected to their new respective IETF sites.  Since
this serves no purpose and only adds network overhead, update our
links to the new locations.

Backpatch to all supported versions.

Discussion: https://postgr.es/m/3C1CEA99-FCED-447D-9858-5A579B4C6687@yesql.se
Backpatch-through: v12

Author: danielgustafsson

doc/src/sgml/acronyms.sgml

@@ -634,7 +634,7 @@
       <ulink
       url="https://en.wikipedia.org/wiki/Server_Name_Indication">
        Server Name Indication</ulink>,
-      <ulink url="https://tools.ietf.org/html/rfc6066#section-3">RFC 6066</ulink>
+      <ulink url="https://datatracker.ietf.org/doc/html/rfc6066#section-3">RFC 6066</ulink>
      </para>
     </listitem>
    </varlistentry>

doc/src/sgml/catalogs.sgml

@@ -1625,7 +1625,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
 </synopsis>
    where <replaceable>salt</replaceable>, <replaceable>StoredKey</replaceable> and
    <replaceable>ServerKey</replaceable> are in Base64 encoded format. This format is
-   the same as that specified by <ulink url="https://tools.ietf.org/html/rfc5803">RFC 5803</ulink>.
+   the same as that specified by <ulink url="https://datatracker.ietf.org/doc/html/rfc5803">RFC 5803</ulink>.
   </para>
 
   <para>

doc/src/sgml/charset.sgml

@@ -1702,7 +1702,7 @@ ORDER BY c COLLATE ebcdic;
      </listitem>
      <listitem>
       <para>
-       <ulink url="https://tools.ietf.org/html/bcp47">BCP 47</ulink>
+       <ulink url="https://www.rfc-editor.org/info/bcp47">BCP 47</ulink>
       </para>
      </listitem>
      <listitem>
@@ -3399,7 +3399,7 @@ RESET client_encoding;
       </varlistentry>
 
       <varlistentry>
-       <term><ulink url="https://tools.ietf.org/html/rfc3629">RFC 3629</ulink></term>
+       <term><ulink url="https://datatracker.ietf.org/doc/html/rfc3629">RFC 3629</ulink></term>
 
        <listitem>
         <para>

doc/src/sgml/client-auth.sgml

@@ -691,7 +691,7 @@ include_dir         <replaceable>directory</replaceable>
        entire <literal>Distinguished Name (DN)</literal> of the certificate.
        This option is probably best used in conjunction with a username map.
        The comparison is done with the <literal>DN</literal> in
-       <ulink url="https://tools.ietf.org/html/rfc2253">RFC 2253</ulink>
+       <ulink url="https://datatracker.ietf.org/doc/html/rfc2253">RFC 2253</ulink>
        format. To see the <literal>DN</literal> of a client certificate
        in this format, do
 <programlisting>
@@ -1090,7 +1090,7 @@ omicron         bryanh                  guest1
      <para>
       <link linkend="auth-ident">Ident authentication</link>, which
       relies on an <quote>Identification Protocol</quote>
-      (<ulink url="https://tools.ietf.org/html/rfc1413">RFC 1413</ulink>)
+      (<ulink url="https://datatracker.ietf.org/doc/html/rfc1413">RFC 1413</ulink>)
       service on the client's machine.  (On local Unix-socket connections,
       this is treated as peer authentication.)
      </para>
@@ -1229,7 +1229,7 @@ omicron         bryanh                  guest1
       <para>
        The method <literal>scram-sha-256</literal> performs SCRAM-SHA-256
        authentication, as described in
-       <ulink url="https://tools.ietf.org/html/rfc7677">RFC 7677</ulink>.  It
+       <ulink url="https://datatracker.ietf.org/doc/html/rfc7677">RFC 7677</ulink>.  It
        is a challenge-response scheme that prevents password sniffing on
        untrusted connections and supports storing passwords on the server in a
        cryptographically hashed form that is thought to be secure.
@@ -1336,7 +1336,7 @@ omicron         bryanh                  guest1
    <para>
     <productname>GSSAPI</productname> is an industry-standard protocol
     for secure authentication defined in
-    <ulink url="https://tools.ietf.org/html/rfc2743">RFC 2743</ulink>.
+    <ulink url="https://datatracker.ietf.org/doc/html/rfc2743">RFC 2743</ulink>.
     <productname>PostgreSQL</productname>
     supports <productname>GSSAPI</productname> for authentication,
     communications encryption, or both.
@@ -1651,7 +1651,7 @@ omicron         bryanh                  guest1
 
    <para>
     The <quote>Identification Protocol</quote> is described in
-    <ulink url="https://tools.ietf.org/html/rfc1413">RFC 1413</ulink>.
+    <ulink url="https://datatracker.ietf.org/doc/html/rfc1413">RFC 1413</ulink>.
     Virtually every Unix-like
     operating system ships with an ident server that listens on TCP
     port 113 by default. The basic functionality of an ident server
@@ -1820,7 +1820,7 @@ omicron         bryanh                  guest1
        <para>
         Set to 1 to make the connection between PostgreSQL and the LDAP server
         use TLS encryption.  This uses the <literal>StartTLS</literal>
-        operation per <ulink url="https://tools.ietf.org/html/rfc4513">RFC 4513</ulink>.
+        operation per <ulink url="https://datatracker.ietf.org/doc/html/rfc4513">RFC 4513</ulink>.
         See also the <literal>ldapscheme</literal> option for an alternative.
        </para>
       </listitem>
@@ -1915,7 +1915,7 @@ omicron         bryanh                  guest1
        <term><literal>ldapurl</literal></term>
        <listitem>
         <para>
-         An <ulink url="https://tools.ietf.org/html/rfc4516">RFC 4516</ulink>
+         An <ulink url="https://datatracker.ietf.org/doc/html/rfc4516">RFC 4516</ulink>
          LDAP URL.  This is an alternative way to write some of the
          other LDAP options in a more compact and standard form.  The format is
 <synopsis>
@@ -1978,7 +1978,7 @@ ldap[s]://<replaceable>host</replaceable>[:<replaceable>port</replaceable>]/<rep
      <productname>OpenLDAP</productname> as the LDAP client library, the
      <literal>ldapserver</literal> setting may be omitted.  In that case, a
      list of host names and ports is looked up via
-     <ulink url="https://tools.ietf.org/html/rfc2782">RFC 2782</ulink> DNS SRV records.
+     <ulink url="https://datatracker.ietf.org/doc/html/rfc2782">RFC 2782</ulink> DNS SRV records.
      The name <literal>_ldap._tcp.DOMAIN</literal> is looked up, where
      <literal>DOMAIN</literal> is extracted from <literal>ldapbasedn</literal>.
    </para>

doc/src/sgml/datatype.sgml

@@ -2471,7 +2471,7 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
       the date and time.  <productname>PostgreSQL</productname> accepts that format on
       input, but on output it uses a space rather than <literal>T</literal>, as shown
       above.  This is for readability and for consistency with
-      <ulink url="https://tools.ietf.org/html/rfc3339">RFC 3339</ulink> as
+      <ulink url="https://datatracker.ietf.org/doc/html/rfc3339">RFC 3339</ulink> as
       well as some other database systems.
      </para>
     </note>
@@ -4367,7 +4367,7 @@ SELECT to_tsvector( 'postgraduate' ), to_tsquery( 'postgres:*' );
 
    <para>
     The data type <type>uuid</type> stores Universally Unique Identifiers
-    (UUID) as defined by <ulink url="https://tools.ietf.org/html/rfc4122">RFC 4122</ulink>,
+    (UUID) as defined by <ulink url="https://datatracker.ietf.org/doc/html/rfc4122">RFC 4122</ulink>,
     ISO/IEC 9834-8:2005, and related standards.
     (Some systems refer to this data type as a globally unique identifier, or
     GUID,<indexterm><primary>GUID</primary></indexterm> instead.)  This

doc/src/sgml/ecpg.sgml

@@ -3317,7 +3317,7 @@ int PGTYPEStimestamp_fmt_asc(timestamp *ts, char *output, int str_len, char *fmt
            <literal>%z</literal> - is replaced by the time zone offset from
            UTC; a leading plus sign stands for east of UTC, a minus sign for
            west of UTC, hours and minutes follow with two digits each and no
-           delimiter between them (common form for <ulink url="https://tools.ietf.org/html/rfc822">RFC 822</ulink> date headers).
+           delimiter between them (common form for <ulink url="https://datatracker.ietf.org/doc/html/rfc822">RFC 822</ulink> date headers).
           </para>
          </listitem>
          <listitem>

doc/src/sgml/func.sgml

@@ -4901,7 +4901,7 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
      <listitem>
       <para>
        The <literal>base64</literal> format is that
-       of <ulink url="https://tools.ietf.org/html/rfc2045#section-6.8">RFC
+       of <ulink url="https://datatracker.ietf.org/doc/html/rfc2045#section-6.8">RFC
        2045 Section 6.8</ulink>.  As per the <acronym>RFC</acronym>, encoded lines are
        broken at 76 characters.  However instead of the MIME CRLF
        end-of-line marker, only a newline is used for end-of-line.
@@ -14198,7 +14198,7 @@ CREATE TYPE rainbow AS ENUM ('red', 'orange', 'yellow', 'green', 'blue', 'purple
 <function>uuid_extract_version</function> (uuid) <returnvalue>smallint</returnvalue>
 </synopsis>
    This function extracts the version from a UUID of the variant described by
-   <ulink url="https://tools.ietf.org/html/rfc4122">RFC 4122</ulink>.  For
+   <ulink url="https://datatracker.ietf.org/doc/html/rfc4122">RFC 4122</ulink>.  For
    other variants, this function returns null.  For example, for a UUID
    generated by <function>gen_random_uuid</function>, this function will
    return 4.
@@ -15537,7 +15537,7 @@ table2-mapping
    values, with an additional SQL/JSON null value, and composite data structures
    that use JSON arrays and objects. The model is a formalization of the implied
    data model in the JSON specification
-   <ulink url="https://tools.ietf.org/html/rfc7159">RFC 7159</ulink>.
+   <ulink url="https://datatracker.ietf.org/doc/html/rfc7159">RFC 7159</ulink>.
   </para>
 
   <para>

doc/src/sgml/json.sgml

@@ -13,7 +13,7 @@
 
  <para>
   JSON data types are for storing JSON (JavaScript Object Notation)
-  data, as specified in <ulink url="https://tools.ietf.org/html/rfc7159">RFC
+  data, as specified in <ulink url="https://datatracker.ietf.org/doc/html/rfc7159">RFC
   7159</ulink>. Such data can also be stored as <type>text</type>, but
   the JSON data types have the advantage of enforcing that each
   stored value is valid according to the JSON rules.  There are also

doc/src/sgml/libpq.sgml

@@ -920,7 +920,7 @@ PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
     connection parameters.  There are two accepted formats for these strings:
     plain keyword/value strings
     and URIs.  URIs generally follow
-    <ulink url="https://tools.ietf.org/html/rfc3986">RFC
+    <ulink url="https://datatracker.ietf.org/doc/html/rfc3986">RFC
     3986</ulink>, except that multi-host connection strings are allowed
     as further described below.
    </para>
@@ -1005,7 +1005,7 @@ postgresql:///mydb?host=localhost&amp;port=5433
 
    <para>
     The connection <acronym>URI</acronym> needs to be encoded with <ulink
-    url="https://tools.ietf.org/html/rfc3986#section-2.1">percent-encoding</ulink>
+    url="https://datatracker.ietf.org/doc/html/rfc3986#section-2.1">percent-encoding</ulink>
     if it includes symbols with special meaning in any of its parts.  Here is
     an example where the equal sign (<literal>=</literal>) is replaced with
     <literal>%3D</literal> and the space character with
@@ -9343,7 +9343,7 @@ user=admin
    LDAP query will be performed. The result must be a list of
    <literal>keyword = value</literal> pairs which will be used to set
    connection options.  The URL must conform to
-   <ulink url="https://tools.ietf.org/html/rfc1959">RFC 1959</ulink>
+   <ulink url="https://datatracker.ietf.org/doc/html/rfc1959">RFC 1959</ulink>
    and be of the form
 <synopsis>
 ldap://[<replaceable>hostname</replaceable>[:<replaceable>port</replaceable>]]/<replaceable>search_base</replaceable>?<replaceable>attribute</replaceable>?<replaceable>search_scope</replaceable>?<replaceable>filter</replaceable>
@@ -9487,7 +9487,7 @@ ldap://ldap.acme.com/cn=dbserver,cn=hosts?pgconnectinfo?base?(objectclass=*)
    <para>
     For backward compatibility with earlier versions of PostgreSQL, the host
     IP address is verified in a manner different
-    from <ulink url="https://tools.ietf.org/html/rfc6125">RFC 6125</ulink>.
+    from <ulink url="https://datatracker.ietf.org/doc/html/rfc6125">RFC 6125</ulink>.
     The host IP address is always matched against <literal>dNSName</literal>
     SANs as well as <literal>iPAddress</literal> SANs, and can be matched
     against the Common Name attribute if no relevant SANs exist.

doc/src/sgml/pgcrypto.sgml

@@ -442,7 +442,7 @@ gen_salt(type text [, iter_count integer ]) returns text
 
   <para>
    The functions here implement the encryption part of the OpenPGP
-   (<ulink url="https://tools.ietf.org/html/rfc4880">RFC 4880</ulink>)
+   (<ulink url="https://datatracker.ietf.org/doc/html/rfc4880">RFC 4880</ulink>)
    standard.  Supported are both symmetric-key and public-key encryption.
   </para>