Added DHCPv6 vendor data generation for DNS queries

New library added for generating the vendor data in DHCPv6

Added support for storage of DNS queries in BBR

nanostack/ws_bbr_api.h

@@ -490,7 +490,8 @@ int ws_bbr_radius_timing_validate(int8_t interface_id, bbr_radius_timing_t *timi
  *
  * This function can be called multiple times.
  * if domain name matches a existing entry address is updated.
- * If address and domain name is set to NULL entire list is cleared
+ * If domain name is set to NULL entire list is cleared
+ * if address is set to NULL the Domain name is removed from the list.
  *
  * \param interface_id Network interface ID.
  * \param address The address of the DNS query result.

source/6LoWPAN/ws/ws_bbr_api.c

@@ -19,6 +19,7 @@
 #include "nsconfig.h"
 #include "ns_types.h"
 #include "ns_trace.h"
+#include "nsdynmemLIB.h"
 #include "net_interface.h"
 #include "socket_api.h"
 #include "eventOS_event.h"
@@ -41,6 +42,7 @@
 #include "6LoWPAN/ws/ws_pae_controller.h"
 #include "DHCPv6_Server/DHCPv6_server_service.h"
 #include "DHCPv6_client/dhcpv6_client_api.h"
+#include "libDHCPv6/libDHCPv6_vendordata.h"
 #include "libNET/src/net_dns_internal.h"
 
 
@@ -93,6 +95,17 @@ static rpl_dodag_conf_t rpl_conf = {
     .dio_redundancy_constant = WS_RPL_DIO_REDUNDANCY_SMALL
 };
 
+typedef struct dns_resolution {
+    /** Resolved address for the domain*/
+    uint8_t address[16];
+    /** Domain name string */
+    char *domain_name;
+} dns_resolution_t;
+
+#define MAX_DNS_RESOLUTIONS 4
+
+static dns_resolution_t pre_resolved_dns_queries[MAX_DNS_RESOLUTIONS] = {0};
+
 static void ws_bbr_rpl_version_timer_start(protocol_interface_info_entry_t *cur, uint8_t version)
 {
     // Set the next timeout value for version update
@@ -368,7 +381,8 @@ static bool wisun_dhcp_address_add_cb(int8_t interfaceId, dhcp_address_cache_upd
     wisun_bbr_na_send(backbone_interface_id, address_info->allocatedAddress);
     return true;
 }
-static void ws_bbr_dhcp_server_dns_info_update(protocol_interface_info_entry_t *cur)
+
+static void ws_bbr_dhcp_server_dns_info_update(protocol_interface_info_entry_t *cur, uint8_t *global_id)
 {
     //add DNS server information to DHCP server that is learned from the backbone interface.
     uint8_t dns_server_address[16];
@@ -381,9 +395,34 @@ static void ws_bbr_dhcp_server_dns_info_update(protocol_interface_info_entry_t *
     }
 
     //TODO Generate vendor data in Wi-SUN network include the cached DNS query results in some sort of TLV format
-    (void)dhcp_vendor_data_ptr;
-    (void)dhcp_vendor_data_len;
-    //DHCPv6_server_service_set_vendor_data(cur->id, dhcp_vendor_data_ptr, dhcp_vendor_data_len);
+    int vendor_data_len = 0;
+    for (int n = 0; n < MAX_DNS_RESOLUTIONS; n++) {
+        if (pre_resolved_dns_queries[n].domain_name != NULL) {
+            vendor_data_len += net_dns_option_vendor_option_data_dns_query_length(pre_resolved_dns_queries[n].domain_name);
+        }
+    }
+    if (vendor_data_len) {
+        ns_dyn_mem_free(dhcp_vendor_data_ptr);
+        dhcp_vendor_data_ptr = ns_dyn_mem_alloc(vendor_data_len);
+        if (!dhcp_vendor_data_ptr) {
+            tr_warn("Vendor info set fail");
+            return;
+        }
+        dhcp_vendor_data_len = vendor_data_len;
+    }
+    if (dhcp_vendor_data_ptr) {
+        // Write vendor data
+        uint8_t *ptr = dhcp_vendor_data_ptr;
+        for (int n = 0; n < MAX_DNS_RESOLUTIONS; n++) {
+            if (pre_resolved_dns_queries[n].domain_name != NULL) {
+                ptr = net_dns_option_vendor_option_data_dns_query_write(ptr, pre_resolved_dns_queries[n].address, pre_resolved_dns_queries[n].domain_name);
+                tr_info("set DNS query result for %s, addr: %s", pre_resolved_dns_queries[n].domain_name, tr_ipv6(pre_resolved_dns_queries[n].address));
+            }
+        }
+    }
+
+    (void)global_id;
+    //DHCPv6_server_service_set_vendor_data(cur->id, global_id, ARM_ENTERPRISE_NUMBER, dhcp_vendor_data_ptr, dhcp_vendor_data_len);
 }
 
 static void ws_bbr_dhcp_server_start(protocol_interface_info_entry_t *cur, uint8_t *global_id, uint32_t dhcp_address_lifetime)
@@ -406,7 +445,7 @@ static void ws_bbr_dhcp_server_start(protocol_interface_info_entry_t *cur, uint8
     //SEt max value for not limiting address allocation
     DHCPv6_server_service_set_max_clients_accepts_count(cur->id, global_id, MAX_SUPPORTED_ADDRESS_LIST_SIZE);
 
-    ws_bbr_dhcp_server_dns_info_update(cur);
+    ws_bbr_dhcp_server_dns_info_update(cur, global_id);
 
     ws_dhcp_client_address_request(cur, global_id, ll);
 }
@@ -594,7 +633,7 @@ static void ws_bbr_rpl_status_check(protocol_interface_info_entry_t *cur)
             // Add also global prefix and route to RPL
             rpl_control_update_dodag_route(protocol_6lowpan_rpl_root_dodag, current_global_prefix, 64, 0, WS_ROUTE_LIFETIME, false);
         }
-        ws_bbr_dhcp_server_dns_info_update(cur);
+        ws_bbr_dhcp_server_dns_info_update(cur, current_global_prefix);
     }
 }
 void ws_bbr_pan_version_increase(protocol_interface_info_entry_t *cur)
@@ -1200,7 +1239,7 @@ int ws_bbr_dns_query_result_set(int8_t interface_id, const uint8_t address[16],
 {
 #ifdef HAVE_WS_BORDER_ROUTER
     protocol_interface_info_entry_t *cur = protocol_stack_interface_info_get_by_id(interface_id);
-    if (!cur || !address || !domain_name_ptr) {
+    if (!cur) {
         return -1;
     }
 
@@ -1210,10 +1249,62 @@ int ws_bbr_dns_query_result_set(int8_t interface_id, const uint8_t address[16],
      *
      * This is included in the vendor extension where the format is decided by the vendor
      */
-    // TODO search if entry exists replace if address is NULL delete the entry
-    // TODO This information should expire if not updated by client
 
-    ws_bbr_dhcp_server_dns_info_update(cur);
+    // Delete all entries
+    if (!domain_name_ptr) {
+        for (int n = 0; n < MAX_DNS_RESOLUTIONS; n++) {
+            // Delete all entries
+            memset(pre_resolved_dns_queries[n].address, 0, 16);
+            ns_dyn_mem_free(pre_resolved_dns_queries[n].domain_name);
+            pre_resolved_dns_queries[n].domain_name = NULL;
+        }
+        goto update_information;
+    }
+
+    // Update existing entries or delete
+    for (int n = 0; n < MAX_DNS_RESOLUTIONS; n++) {
+        if (pre_resolved_dns_queries[n].domain_name != NULL &&
+                strcasecmp(pre_resolved_dns_queries[n].domain_name, domain_name_ptr) == 0) {
+            // Matching query updated
+            if (address) {
+                // Update address
+                memcpy(pre_resolved_dns_queries[n].address, address, 16);
+            } else {
+                // delete entry
+                memset(pre_resolved_dns_queries[n].address, 0, 16);
+                ns_dyn_mem_free(pre_resolved_dns_queries[n].domain_name);
+                pre_resolved_dns_queries[n].domain_name = NULL;
+            }
+            goto update_information;
+        }
+    }
+
+    if (address && domain_name_ptr) {
+        // Store new entry to the list
+        for (int n = 0; n < MAX_DNS_RESOLUTIONS; n++) {
+            if (pre_resolved_dns_queries[n].domain_name == NULL) {
+                // Free entry found
+                pre_resolved_dns_queries[n].domain_name  = ns_dyn_mem_alloc(strlen(domain_name_ptr) + 1);
+                if (!pre_resolved_dns_queries[n].domain_name) {
+                    // Out of memory
+                    return -2;
+                }
+                memcpy(pre_resolved_dns_queries[n].address, address, 16);
+                strcpy(pre_resolved_dns_queries[n].domain_name, domain_name_ptr);
+                goto update_information;
+            }
+        }
+        // No room to store new field
+        return -3;
+    }
+
+update_information:
+    if (memcmp(current_global_prefix, ADDR_UNSPECIFIED, 8) == 0) {
+        // Not in active state so changes are activated after start
+        return 0;
+    }
+
+    ws_bbr_dhcp_server_dns_info_update(cur, current_global_prefix);
     return 0;
 #else
     (void) interface_id;

source/libDHCPv6/libDHCPv6_vendordata.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2020, Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "nsconfig.h"
+#include "ns_types.h"
+#include "ns_trace.h"
+#include <string.h>
+#include "common_functions.h"
+#include "libDHCPv6.h"
+#include "libDHCPv6_vendordata.h"
+
+
+
+/* DHCPv6 vendor options to distribute ARM vendor data*/
+
+uint16_t net_dns_option_vendor_option_data_dns_query_length(char *domain)
+{
+    return 4 + 16 + strlen(domain) + 1;
+}
+
+uint8_t *net_dns_option_vendor_option_data_dns_query_write(uint8_t *ptr, uint8_t *address, char *domain)
+{
+    int domain_len = strlen(domain);
+    int length = 16 + domain_len + 1;
+
+    ptr = common_write_16_bit(ARM_DHCP_VENDOR_DATA_DNS_QUERY_RESULT, ptr);
+    ptr = common_write_16_bit(length, ptr);
+    memcpy(ptr, address, 16);
+    ptr += 16;
+    memcpy(ptr, domain, domain_len + 1);
+    ptr += domain_len + 1;
+    return ptr;
+}

source/libDHCPv6/libDHCPv6_vendordata.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2020, Arm Limited and affiliates.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LIBDHCPV6_VENDOR_DATA_H_
+#define LIBDHCPV6_VENDOR_DATA_H_
+
+
+/*ARM enterprise number used to identify ARM generated Vendor data options*/
+#define ARM_ENTERPRISE_NUMBER 4128
+
+/* ARM Defined vendor data option to distribute DNS query results through DHCP server
+ * Format
+ *
+ * uint8_t address[16]
+ * domain string nul terminated.
+ *
+ * multiple results must be in separated vendor option data fields
+ * */
+#define ARM_DHCP_VENDOR_DATA_DNS_QUERY_RESULT 297
+
+/* DHCPv6 vendor options to distribute ARM vendor data*/
+
+uint16_t net_dns_option_vendor_option_data_dns_query_length(char *domain);
+uint8_t *net_dns_option_vendor_option_data_dns_query_write(uint8_t *ptr, uint8_t *address, char *domain);
+
+
+
+#endif /* LIBDHCPV6_VENDOR_DATA_H_ */

sources.mk

@@ -205,6 +205,7 @@ SRCS += \
 	source/DHCPv6_client/dhcpv6_client_service.c \
 	source/libDHCPv6/dhcp_service_api.c \
 	source/libDHCPv6/libDHCPv6.c \
+	source/libDHCPv6/libDHCPv6_vendordata.c \
 	source/libDHCPv6/libDHCPv6_server.c \
 	source/Service_Libs/utils/ns_crc.c \
 	source/Service_Libs/utils/isqrt.c \