[#3141] addressed review comments

- Mostly further corrections in ARM docs and in comments.

doc/examples/kea4/all-options.json

@@ -1641,7 +1641,7 @@
         // For each DNR Instance comma delimited fields must be provided:
         // - service priority (mandatory),
         // - ADN (mandatory),
-        // - IP address/es (optional - if more than one - they must be space-separated)
+        // - IP address(es) (optional - if more than one - they must be space-separated)
         // - SvcParams (optional - if more than one - they must be space-separated;
         //   to provide more than one alpn-id separate them with double-backslash escaped comma like in the
         //   example below).

doc/examples/kea6/all-options.json

@@ -1820,7 +1820,7 @@
         // DNR option may be configured using convenient notation. Comma separated fields must be provided:
         // - service priority (mandatory),
         // - ADN (mandatory),
-        // - IP address/es (optional - if more than one - they must be space-separated)
+        // - IP address(es) (optional - if more than one - they must be space-separated)
         // - SvcParams (optional - if more than one - they must be space-separated;
         //   to provide more than one alpn-id separate them with double-backslash escaped comma like in the
         //   example below).

doc/sphinx/arm/dhcp4-srv.rst

@@ -4731,7 +4731,7 @@ point.
 DNR (Discovery of Network-designated Resolvers) Options for DHCPv4
 ------------------------------------------------------------------
 
-One of the more recently added option is the Discovery of
+One of the more recently added options is the Discovery of
 Network-designated Resolvers or DNR option,
 introduced in `RFC 9463 <https://tools.ietf.org/html/rfc9463>`__. The goal of that RFC is
 to provide a way to communicate location of DNS resolvers available over means other than
@@ -4749,11 +4749,11 @@ For detailed example how to configure DNR option, see :ref:`dnr6-options`.
 The only difference for DNR DHCPv4 options configuration is that it allows
 to configure more than one DNR instance and the DNR instances are separated
 with the "pipe" (``0x7C``) character.
-For each DNR Instance comma delimited fields must be provided:
+For each DNR Instance comma delimited fields must be provided in the following order:
 
 - Service Priority (mandatory),
 - ADN FQDN (mandatory),
-- IP address/es (optional - if more than one - they must be space-separated)
+- IP address(es) (optional - if more than one - they must be space-separated)
 - SvcParams as a set of key=value pairs (optional - if more than one - they must be space-separated;
   to provide more than one alpn-id separate them with double backslash escaped comma like in the
   example below).

doc/sphinx/arm/dhcp6-srv.rst

@@ -2070,19 +2070,19 @@ Parameters option.
 DNR (Discovery of Network-designated Resolvers) Options for DHCPv6
 ------------------------------------------------------------------
 
-One of the more recently added option is the Discovery of
+One of the more recently added options is the Discovery of
 Network-designated Resolvers or DNR option,
 introduced in `RFC 9463 <https://www.rfc-editor.org/rfc/rfc9463>`__. The goal of that RFC is
 to provide a way to communicate location of DNS resolvers available over means other than
 the classic DNS over UDP port 53. At the time of this writing, the supported technologies
 are DoT (DNS-over-TLS), DoH (DNS-over-HTTPS), and DoQ (DNS-over-QUIC), but the option was
 designed to be extensible to accommodate other protocols in the future.
 
-DNR option may be configured using convenient notation. Comma delimited fields must be provided:
+DNR option may be configured using convenient notation. Comma delimited fields must be provided in the following order:
 
 - Service Priority (mandatory),
 - ADN FQDN (mandatory),
-- IP address/es (optional - if more than one - they must be space-separated)
+- IP address(es) (optional - if more than one - they must be space-separated)
 - SvcParams as a set of key=value pairs (optional - if more than one - they must be space-separated;
   to provide more than one alpn-id separate them with double backslash escaped comma like in the
   example below).
@@ -2109,20 +2109,19 @@ The above option will be encoded on-wire as follows:
 
 ::
 
-        // 00 64 - service priority (100 in hex as unsigned 16 bit integer)
-        // 00 12 - length of the Authentication Domain Name (name of the resolver) FQDN (18 in hex as unsigned 16 bit integer)
-        // 04 64 6f 74 31 07 65 78 61 6d 70 6c 65 03 6f 72 67 00 - 18 octets of the ADN FQDN
-        // 00 20 - 32 octets is the length of the following two IPv6 addresses
-        // 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01 - 2001:db8::1
-        // 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 02 - 2001:db8::2
-        // Remaining part is to be interpreted as SvcParams field. In particular:
-        // 00 01 - next record is alpn
-        // 00 04 - length of the alpn SvcParamValue field (4 octets)
-        // 03    - length of the following alpn-id coded on one octet
-        // 64 6f 74 - "dot" - value of the alpn
-        // 00 03 - next record is port
-        // 00 02 - length of the SvcParamValue field is 2 octets
-        // 21 52 - the actual is 0x2152 or 8530 in decimal
+        00 64 - service priority (100 in hex as unsigned 16 bit integer)
+        00 12 - length of the Authentication Domain Name (name of the resolver) FQDN (18 in hex as unsigned 16 bit integer)
+        04 64 6f 74 31 07 65 78 61 6d 70 6c 65 03 6f 72 67 00 - 18 octets of the ADN FQDN
+        00 20 - 32 octets is the length of the following two IPv6 addresses
+        20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01 - 2001:db8::1
+        20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 02 - 2001:db8::2
+        00 01 - SvsParams begin - this is alpn SvcParamKey
+        00 04 - length of the alpn SvcParamValue field (4 octets)
+        03    - length of the following alpn-id coded on one octet
+        64 6f 74 - "dot" - value of the alpn
+        00 03 - this is port SvcParamKey
+        00 02 - length of the SvcParamValue field is 2 octets
+        21 52 - the actual value is 0x2152 or 8530 in decimal
 
 The following example shows how to configure more than one ``ALPN`` protocol in Service Parameters.
 The example specifies a resolver known as ``resolver.example`` that supports:
@@ -2144,26 +2143,25 @@ The above option will be encoded on-wire as follows:
 
 ::
 
-        // 00 96 - service priority (150 in hex as unsigned 16 bit integer)
-        // 00 12 - length of the Authentication Domain Name (name of the resolver) FQDN (18 in hex as unsigned 16 bit integer)
-        // 08 72 65 73 6f 6c 76 65 72 07 65 78 61 6d 70 6c 65 00 - 18 octets of the ADN FQDN
-        // 00 20 - 32 octets is the length of the following two IPv6 addresses
-        // 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01 - 2001:db8::1
-        // 20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 02 - 2001:db8::2
-        // Remaining part is to be interpreted as SvcParams field. In particular:
-        // 00 01 - next record is alpn
-        // 00 0e - length of the alpn SvcParamValue field (14 octets)
-        // 03    - length of the following alpn-id coded on one octet
-        // 64 6f 74 - "dot" - value of the alpn
-        // 03    - length of the following alpn-id coded on one octet
-        // 64 6f 71 - "doq" - value of the alpn
-        // 02    - length of the following alpn-id coded on one octet
-        // 68 32 - "h2" - value of the alpn "HTTP/2 over TLS"
-        // 02    - length of the following alpn-id coded on one octet
-        // 68 33 - "h3" - value of the alpn "HTTP/3"
-        // 00 07 - next record is dohpath
-        // 00 08 - length of the SvcParamValue field is 8 octets
-        // 2f 71 7b 3f 64 6e 73 7d - "/q{?dns}" dohpath
+        00 96 - service priority (150 in hex as unsigned 16 bit integer)
+        00 12 - length of the Authentication Domain Name (name of the resolver) FQDN (18 in hex as unsigned 16 bit integer)
+        08 72 65 73 6f 6c 76 65 72 07 65 78 61 6d 70 6c 65 00 - 18 octets of the ADN FQDN
+        00 20 - 32 octets is the length of the following two IPv6 addresses
+        20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 01 - 2001:db8::1
+        20 01 0d b8 00 00 00 00 00 00 00 00 00 00 00 02 - 2001:db8::2
+        00 01 - SvsParams begin - this is alpn SvcParamKey
+        00 0e - length of the alpn SvcParamValue field (14 octets)
+        03    - length of the following alpn-id coded on one octet
+        64 6f 74 - "dot" - value of the alpn
+        03    - length of the following alpn-id coded on one octet
+        64 6f 71 - "doq" - value of the alpn
+        02    - length of the following alpn-id coded on one octet
+        68 32 - "h2" - value of the alpn "HTTP/2 over TLS"
+        02    - length of the following alpn-id coded on one octet
+        68 33 - "h3" - value of the alpn "HTTP/3"
+        00 07 - this is dohpath SvcParamKey
+        00 08 - length of the SvcParamValue field is 8 octets
+        2f 71 7b 3f 64 6e 73 7d - "/q{?dns}" dohpath
 
 
 .. note::

src/lib/dhcp/option4_dnr.cc

@@ -573,7 +573,7 @@ DnrInstance::parseDnrInstanceConfigData(const std::string& config_txt) {
     if (tokens.size() > 4) {
         isc_throw(BadValue, getLogPrefix() << "Option config supports maximum 4 comma separated "
                                            << "fields: Service Priority, ADN, resolver IP "
-                                           << "address/es and SvcParams");
+                                           << "address(es) and SvcParams");
     }
 
     // parse Service Priority
@@ -606,7 +606,7 @@ DnrInstance::parseDnrInstanceConfigData(const std::string& config_txt) {
     if (tokens.size() > 2) {
         setAdnOnlyMode(false);
 
-        // parse resolver IP address/es
+        // parse resolver IP address(es)
         std::string txt_addresses = str::trim(tokens[2]);
 
         parseIpAddresses(txt_addresses);
@@ -659,9 +659,6 @@ void
 DnrInstance::parseSvcParams(const std::string& txt_svc_params) {
     // SvcParamKey=SvcParamValue pairs are separated with space
     std::vector<std::string> svc_params_pairs = str::tokens(txt_svc_params, std::string(" "));
-    std::vector<std::string> alpn_ids_tokens;
-
-    OutputBuffer out_buf(2);
 
     for (auto const& svc_param_pair : svc_params_pairs) {
         std::vector<std::string> key_val_tokens = str::tokens(str::trim(svc_param_pair), "=");
@@ -760,6 +757,7 @@ DnrInstance::parseSvcParams(const std::string& txt_svc_params) {
     // (...)
     // SvcParamKeys SHALL appear in increasing numeric order.
     // Note that (...) there are no duplicate SvcParamKeys.
+    OutputBuffer out_buf(2);
 
     for (auto const& svc_param_key : SUPPORTED_SVC_PARAMS) {
         auto it = svc_params_map_.find(svc_param_key);

src/lib/dhcp/option4_dnr.h

@@ -214,7 +214,7 @@ class DnrInstance {
 
     /// @brief Setter of the @c dnr_instance_data_length_ field.
     ///
-    /// Size is calculated basing on set Service Priority, ADN, IP address/es and SvcParams.
+    /// Size is calculated basing on set Service Priority, ADN, IP address(es) and SvcParams.
     /// This should be called after all fields are set.
     /// This is only used for DHCPv4 Encrypted DNS %Option.
     void setDnrInstanceDataLength() {
@@ -433,9 +433,9 @@ class DnrInstance {
     ///                 @c svc_params_map_
     std::string svcParamValAsText(const std::pair<uint16_t, OpaqueDataTuple>& svc_param) const;
 
-    /// @brief Parses DNR resolver IP address/es from a piece of convenient notation option config.
+    /// @brief Parses DNR resolver IP address(es) from a piece of convenient notation option config.
     ///
-    /// @param txt_addresses a piece of convenient notation option config holding IP address/es
+    /// @param txt_addresses a piece of convenient notation option config holding IP address(es)
     ///
     /// @throw BadValue Thrown in case parser found wrong format of received string.
     void parseIpAddresses(const std::string& txt_addresses);