Sergey Pastor
Webserver+3d print
Diff: cyclone_tcp/netbios/nbns_responder.c
- Revision:
- 0:8918a71cdbe9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cyclone_tcp/netbios/nbns_responder.c Sat Feb 04 18:15:49 2017 +0000
@@ -0,0 +1,192 @@
+/**
+ * @file nbns_responder.c
+ * @brief NBNS responder (NetBIOS Name Service)
+ *
+ * @section License
+ *
+ * Copyright (C) 2010-2017 Oryx Embedded SARL. All rights reserved.
+ *
+ * This file is part of CycloneTCP Open.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * @author Oryx Embedded SARL (www.oryx-embedded.com)
+ * @version 1.7.6
+ **/
+
+//Switch to the appropriate trace level
+#define TRACE_LEVEL NBNS_TRACE_LEVEL
+
+//Dependencies
+#include "core/net.h"
+#include "netbios/nbns_responder.h"
+#include "netbios/nbns_common.h"
+#include "dns/dns_debug.h"
+#include "debug.h"
+
+//Check TCP/IP stack configuration
+#if (NBNS_RESPONDER_SUPPORT == ENABLED && IPV4_SUPPORT == ENABLED)
+
+
+/**
+ * @brief Process NBNS query message
+ * @param[in] interface Underlying network interface
+ * @param[in] pseudoHeader UDP pseudo header
+ * @param[in] udpHeader UDP header
+ * @param[in] message Pointer to the NBNS query message
+ * @param[in] length Length of the message
+ **/
+
+void nbnsProcessQuery(NetInterface *interface, const Ipv4PseudoHeader *pseudoHeader,
+ const UdpHeader *udpHeader, const NbnsHeader *message, size_t length)
+{
+ size_t pos;
+ DnsQuestion *question;
+
+ //The NBNS query shall contain one question
+ if(ntohs(message->qdcount) != 1)
+ return;
+
+ //Parse NetBIOS name
+ pos = nbnsParseName(message, length, sizeof(DnsHeader), NULL);
+
+ //Invalid name?
+ if(!pos)
+ return;
+ //Malformed NBNS query message?
+ if((pos + sizeof(DnsQuestion)) > length)
+ return;
+
+ //Point to the corresponding entry
+ question = DNS_GET_QUESTION(message, pos);
+
+ //Check the class and the type of the request
+ if(ntohs(question->qclass) != DNS_RR_CLASS_IN)
+ return;
+ if(ntohs(question->qtype) != DNS_RR_TYPE_NB)
+ return;
+
+ //Compare NetBIOS names
+ if(nbnsCompareName(message, length, sizeof(DnsHeader), interface->hostname))
+ {
+ uint16_t destPort;
+ IpAddr destIpAddr;
+
+ //A response packet is always sent to the source UDP port and
+ //source IP address of the request packet
+ destIpAddr.length = sizeof(Ipv4Addr);
+ destIpAddr.ipv4Addr = pseudoHeader->srcAddr;
+
+ //Convert the port number to host byte order
+ destPort = ntohs(udpHeader->srcPort);
+
+ //Send NBNS response
+ nbnsSendResponse(interface, &destIpAddr, destPort, message->id);
+ }
+}
+
+
+/**
+ * @brief Send NBNS response message
+ * @param[in] interface Underlying network interface
+ * @param[in] destIpAddr Destination IP address
+ * @param[in] destPort destination port
+ * @param[in] id 16-bit identifier to be used when sending NBNS query
+ **/
+
+error_t nbnsSendResponse(NetInterface *interface,
+ const IpAddr *destIpAddr, uint16_t destPort, uint16_t id)
+{
+ error_t error;
+ size_t length;
+ size_t offset;
+ NetBuffer *buffer;
+ NbnsHeader *message;
+ NbnsAddrEntry *addrEntry;
+ DnsResourceRecord *record;
+
+ //Allocate a memory buffer to hold the NBNS response message
+ buffer = udpAllocBuffer(DNS_MESSAGE_MAX_SIZE, &offset);
+ //Failed to allocate buffer?
+ if(buffer == NULL)
+ return ERROR_OUT_OF_MEMORY;
+
+ //Point to the NBNS header
+ message = netBufferAt(buffer, offset);
+
+ //Take the identifier from the query message
+ message->id = id;
+
+ //Format NBNS response header
+ message->qr = 1;
+ message->opcode = DNS_OPCODE_QUERY;
+ message->aa = 1;
+ message->tc = 0;
+ message->rd = 1;
+ message->ra = 1;
+ message->z = 0;
+ message->b = 0;
+ message->rcode = DNS_RCODE_NO_ERROR;
+
+ //The NBNS response contains 1 answer resource record
+ message->qdcount = 0;
+ message->ancount = HTONS(1);
+ message->nscount = 0;
+ message->arcount = 0;
+
+ //NBNS response message length
+ length = sizeof(DnsHeader);
+
+ //Encode the host name using the NBNS name notation
+ length += nbnsEncodeName(interface->hostname, (uint8_t *) message + length);
+
+ //Point to the corresponding resource record
+ record = DNS_GET_RESOURCE_RECORD(message, length);
+ //Fill in resource record
+ record->rtype = HTONS(DNS_RR_TYPE_NB);
+ record->rclass = HTONS(DNS_RR_CLASS_IN);
+ record->ttl = HTONL(NBNS_DEFAULT_RESOURCE_RECORD_TTL);
+ record->rdlength = HTONS(sizeof(NbnsAddrEntry));
+
+ //Point to the address entry array
+ addrEntry = (NbnsAddrEntry *) record->rdata;
+ //Fill in address entry
+ addrEntry->flags = HTONS(NBNS_G_UNIQUE | NBNS_ONT_BNODE);
+ addrEntry->addr = interface->ipv4Context.addr;
+
+ //Update the length of the NBNS response message
+ length += sizeof(DnsResourceRecord) + sizeof(NbnsAddrEntry);
+
+ //Adjust the length of the multi-part buffer
+ netBufferSetLength(buffer, offset + length);
+
+ //Debug message
+ TRACE_INFO("Sending NBNS message (%" PRIuSIZE " bytes)...\r\n", length);
+ //Dump message
+ dnsDumpMessage((DnsHeader *) message, length);
+
+ //A response packet is always sent to the source UDP port and
+ //source IP address of the request packet
+ error = udpSendDatagramEx(interface, NBNS_PORT, destIpAddr,
+ destPort, buffer, offset, IPV4_DEFAULT_TTL);
+
+ //Free previously allocated memory
+ netBufferFree(buffer);
+ //Return status code
+ return error;
+}
+
+#endif
+