-#ifndef _GNVPN_DNSP_H_
-#define _GNVPN_DNSP_H_
+/*
+ This file is part of GNUnet
+ (C) 2010, 2011, 2012 Christian Grothoff (and other contributing authors)
+
+ GNUnet 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, or (at your
+ option) any later version.
+
+ GNUnet 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 GNUnet; see the file COPYING. If not, write to the
+ Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * @file include/gnunet_dnsparser_lib.h
+ * @brief API for helper library to parse DNS packets.
+ * @author Philipp Toelke
+ * @author Christian Grothoff
+ */
+#ifndef GNUNET_DNSPARSER_LIB_H
+#define GNUNET_DNSPARSER_LIB_H
#include "platform.h"
#include "gnunet_common.h"
-// DNS-Stuff
-GNUNET_NETWORK_STRUCT_BEGIN
+/**
+ * A few common DNS types.
+ */
+#define GNUNET_DNSPARSER_TYPE_A 1
+#define GNUNET_DNSPARSER_TYPE_NS 2
+#define GNUNET_DNSPARSER_TYPE_CNAME 5
+#define GNUNET_DNSPARSER_TYPE_SOA 6
+#define GNUNET_DNSPARSER_TYPE_PTR 12
+#define GNUNET_DNSPARSER_TYPE_MX 15
+#define GNUNET_DNSPARSER_TYPE_TXT 16
+#define GNUNET_DNSPARSER_TYPE_AAAA 28
+#define GNUNET_DNSPARSER_TYPE_SRV 33
+#define GNUNET_DNSPARSER_TYPE_TLSA 52
+
+/**
+ * A few common DNS classes (ok, only one is common, but I list a
+ * couple more to make it clear what we're talking about here).
+ */
+#define GNUNET_DNSPARSER_CLASS_INTERNET 1
+#define GNUNET_DNSPARSER_CLASS_CHAOS 3
+#define GNUNET_DNSPARSER_CLASS_HESIOD 4
-struct dns_static
+#define GNUNET_DNSPARSER_OPCODE_QUERY 0
+#define GNUNET_DNSPARSER_OPCODE_INVERSE_QUERY 1
+#define GNUNET_DNSPARSER_OPCODE_STATUS 2
+
+/**
+ * RFC 1035 codes.
+ */
+#define GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR 0
+#define GNUNET_DNSPARSER_RETURN_CODE_FORMAT_ERROR 1
+#define GNUNET_DNSPARSER_RETURN_CODE_SERVER_FAILURE 2
+#define GNUNET_DNSPARSER_RETURN_CODE_NAME_ERROR 3
+#define GNUNET_DNSPARSER_RETURN_CODE_NOT_IMPLEMENTED 4
+#define GNUNET_DNSPARSER_RETURN_CODE_REFUSED 5
+
+/**
+ * RFC 2136 codes
+ */
+#define GNUNET_DNSPARSER_RETURN_CODE_YXDOMAIN 6
+#define GNUNET_DNSPARSER_RETURN_CODE_YXRRSET 7
+#define GNUNET_DNSPARSER_RETURN_CODE_NXRRSET 8
+#define GNUNET_DNSPARSER_RETURN_CODE_NOT_AUTH 9
+#define GNUNET_DNSPARSER_RETURN_CODE_NOT_ZONE 10
+
+/**
+ * DNS flags (largely RFC 1035 / RFC 2136).
+ */
+struct GNUNET_DNSPARSER_Flags
{
- uint16_t id GNUNET_PACKED;
-
- unsigned rd:1 GNUNET_PACKED; // recursion desired (client -> server)
- unsigned tc:1 GNUNET_PACKED; // message is truncated
- unsigned aa:1 GNUNET_PACKED; // authoritative answer
- unsigned op:4 GNUNET_PACKED; // query:0, inverse q.:1, status: 2
- unsigned qr:1 GNUNET_PACKED; // query:0, response:1
-
- unsigned rcode:4 GNUNET_PACKED; // 0 No error
- // 1 Format error
- // 2 Server failure
- // 3 Name Error
- // 4 Not Implemented
- // 5 Refused
- unsigned z:3 GNUNET_PACKED; // reserved
- unsigned ra:1 GNUNET_PACKED; // recursion available (server -> client)
-
- uint16_t qdcount GNUNET_PACKED; // number of questions
- uint16_t ancount GNUNET_PACKED; // number of answers
- uint16_t nscount GNUNET_PACKED; // number of authority-records
- uint16_t arcount GNUNET_PACKED; // number of additional records
-};
-GNUNET_NETWORK_STRUCT_END
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ /**
+ * Set to 1 if recursion is desired (client -> server)
+ */
+ unsigned int recursion_desired : 1 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if message is truncated
+ */
+ unsigned int message_truncated : 1 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if this is an authoritative answer
+ */
+ unsigned int authoritative_answer : 1 GNUNET_PACKED;
+
+ /**
+ * See GNUNET_DNSPARSER_OPCODE_ defines.
+ */
+ unsigned int opcode : 4 GNUNET_PACKED;
+
+ /**
+ * query:0, response:1
+ */
+ unsigned int query_or_response : 1 GNUNET_PACKED;
+
+ /**
+ * See GNUNET_DNSPARSER_RETURN_CODE_ defines.
+ */
+ unsigned int return_code : 4 GNUNET_PACKED;
+
+ /**
+ * See RFC 4035.
+ */
+ unsigned int checking_disabled : 1 GNUNET_PACKED;
+
+ /**
+ * Response has been cryptographically verified, RFC 4035.
+ */
+ unsigned int authenticated_data : 1 GNUNET_PACKED;
+
+ /**
+ * Always zero.
+ */
+ unsigned int zero : 1 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if recursion is available (server -> client)
+ */
+ unsigned int recursion_available : 1 GNUNET_PACKED;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+
+ /**
+ * query:0, response:1
+ */
+ unsigned int query_or_response : 1 GNUNET_PACKED;
+
+ /**
+ * See GNUNET_DNSPARSER_OPCODE_ defines.
+ */
+ unsigned int opcode : 4 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if this is an authoritative answer
+ */
+ unsigned int authoritative_answer : 1 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if message is truncated
+ */
+ unsigned int message_truncated : 1 GNUNET_PACKED;
+
+ /**
+ * Set to 1 if recursion is desired (client -> server)
+ */
+ unsigned int recursion_desired : 1 GNUNET_PACKED;
-struct dns_pkt
+
+ /**
+ * Set to 1 if recursion is available (server -> client)
+ */
+ unsigned int recursion_available : 1 GNUNET_PACKED;
+
+ /**
+ * Always zero.
+ */
+ unsigned int zero : 1 GNUNET_PACKED;
+
+ /**
+ * Response has been cryptographically verified, RFC 4035.
+ */
+ unsigned int authenticated_data : 1 GNUNET_PACKED;
+
+ /**
+ * See RFC 4035.
+ */
+ unsigned int checking_disabled : 1 GNUNET_PACKED;
+
+ /**
+ * See GNUNET_DNSPARSER_RETURN_CODE_ defines.
+ */
+ unsigned int return_code : 4 GNUNET_PACKED;
+#else
+ #error byteorder undefined
+#endif
+
+} GNUNET_GCC_STRUCT_LAYOUT;
+
+
+/**
+ * A DNS query.
+ */
+struct GNUNET_DNSPARSER_Query
{
- struct dns_static s;
- unsigned char data[1];
+
+ /**
+ * Name of the record that the query is for (0-terminated).
+ */
+ char *name;
+
+ /**
+ * See GNUNET_DNSPARSER_TYPE_*.
+ */
+ uint16_t type;
+
+ /**
+ * See GNUNET_DNSPARSER_CLASS_*.
+ */
+ uint16_t class;
+
};
-struct dns_pkt_parsed
+
+/**
+ * Information from MX records (RFC 1035).
+ */
+struct GNUNET_DNSPARSER_MxRecord
{
- struct dns_static s;
- struct dns_query **queries;
- struct dns_record **answers;
- struct dns_record **nameservers;
- struct dns_record **additional;
+
+ /**
+ * Preference for this entry (lower value is higher preference).
+ */
+ uint16_t preference;
+
+ /**
+ * Name of the mail server.
+ */
+ char *mxhost;
+
};
-struct dns_query_line
+
+/**
+ * Information from SRV records (RFC 2782). The 'service', 'proto'
+ * and 'domain_name' fields together give the DNS-name which for SRV
+ * records is of the form "_$SERVICE._$PROTO.$DOMAIN_NAME". The DNS
+ * parser provides the full name in 'struct DNSPARSER_Record' and the
+ * individual components in the respective fields of this struct.
+ * When serializing, you CAN set the 'name' field of 'struct
+ * GNUNET_DNSPARSER_Record' to NULL, in which case the DNSPARSER code
+ * will populate 'name' from the 'service', 'proto' and 'domain_name'
+ * fields in this struct.
+ */
+struct GNUNET_DNSPARSER_SrvRecord
{
- unsigned short type;
- unsigned short class;
+
+ /**
+ * Service name without the underscore (!). Note that RFC 6335 clarifies the
+ * set of legal characters for service names.
+ */
+ char *service;
+
+ /**
+ * Transport protocol (typcially "tcp" or "udp", but others might be allowed).
+ * Without the underscore (!).
+ */
+ char *proto;
+
+ /**
+ * Domain name for which the record is valid
+ */
+ char *domain_name;
+
+ /**
+ * Hostname offering the service.
+ */
+ char *target;
+
+ /**
+ * Preference for this entry (lower value is higher preference). Clients
+ * will contact hosts from the lowest-priority group first and fall back
+ * to higher priorities if the low-priority entries are unavailable.
+ */
+ uint16_t priority;
+
+ /**
+ * Relative weight for records with the same priority. Clients will use
+ * the hosts of the same (lowest) priority with a probability proportional
+ * to the weight given.
+ */
+ uint16_t weight;
+
+ /**
+ * TCP or UDP port of the service.
+ */
+ uint16_t port;
+
};
-struct dns_query
+
+/**
+ * Information from SOA records (RFC 1035).
+ */
+struct GNUNET_DNSPARSER_SoaRecord
{
- char *name;
- unsigned char namelen;
- unsigned short qtype;
- unsigned short qclass;
+
+ /**
+ *The domainname of the name server that was the
+ * original or primary source of data for this zone.
+ */
+ char *mname;
+
+ /**
+ * A domainname which specifies the mailbox of the
+ * person responsible for this zone.
+ */
+ char *rname;
+
+ /**
+ * The version number of the original copy of the zone.
+ */
+ uint32_t serial;
+
+ /**
+ * Time interval before the zone should be refreshed.
+ */
+ uint32_t refresh;
+
+ /**
+ * Time interval that should elapse before a failed refresh should
+ * be retried.
+ */
+ uint32_t retry;
+
+ /**
+ * Time value that specifies the upper limit on the time interval
+ * that can elapse before the zone is no longer authoritative.
+ */
+ uint32_t expire;
+
+ /**
+ * The bit minimum TTL field that should be exported with any RR
+ * from this zone.
+ */
+ uint32_t minimum_ttl;
+
};
-struct dns_record_line
+
+/**
+ * Binary record information (unparsed).
+ */
+struct GNUNET_DNSPARSER_RawRecord
{
- unsigned short type;
- unsigned short class;
- unsigned int ttl;
- unsigned short data_len;
- unsigned char data;
+
+ /**
+ * Binary record data.
+ */
+ void *data;
+
+ /**
+ * Number of bytes in data.
+ */
+ size_t data_len;
};
-struct dns_record
+
+/**
+ * A DNS response record.
+ */
+struct GNUNET_DNSPARSER_Record
{
+
+ /**
+ * Name of the record that the query is for (0-terminated).
+ */
char *name;
- unsigned char namelen;
- unsigned short type;
- unsigned short class;
- unsigned int ttl;
- unsigned short data_len;
- unsigned char *data;
+
+ /**
+ * Payload of the record (which one of these is valid depends on the 'type').
+ */
+ union
+ {
+
+ /**
+ * For NS, CNAME and PTR records, this is the uncompressed 0-terminated hostname.
+ */
+ char *hostname;
+
+ /**
+ * SOA data for SOA records.
+ */
+ struct GNUNET_DNSPARSER_SoaRecord *soa;
+
+ /**
+ * MX data for MX records.
+ */
+ struct GNUNET_DNSPARSER_MxRecord *mx;
+
+ /**
+ * SRV data for SRV records.
+ */
+ struct GNUNET_DNSPARSER_SrvRecord *srv;
+
+ /**
+ * Raw data for all other types.
+ */
+ struct GNUNET_DNSPARSER_RawRecord raw;
+
+ } data;
+
+
+ /**
+ * When does the record expire?
+ */
+ struct GNUNET_TIME_Absolute expiration_time;
+
+ /**
+ * See GNUNET_DNSPARSER_TYPE_*.
+ */
+ uint16_t type;
+
+ /**
+ * See GNUNET_DNSPARSER_CLASS_*.
+ */
+ uint16_t class;
+
};
-struct dns_pkt_parsed *
-parse_dns_packet (struct dns_pkt *pkt);
+/**
+ * Easy-to-process, parsed version of a DNS packet.
+ */
+struct GNUNET_DNSPARSER_Packet
+{
+ /**
+ * Array of all queries in the packet, must contain "num_queries" entries.
+ */
+ struct GNUNET_DNSPARSER_Query *queries;
-struct dns_pkt *
-unparse_dns_packet (struct dns_pkt_parsed *pkt);
+ /**
+ * Array of all answers in the packet, must contain "num_answers" entries.
+ */
+ struct GNUNET_DNSPARSER_Record *answers;
+ /**
+ * Array of all authority records in the packet, must contain "num_authority_records" entries.
+ */
+ struct GNUNET_DNSPARSER_Record *authority_records;
+
+ /**
+ * Array of all additional answers in the packet, must contain "num_additional_records" entries.
+ */
+ struct GNUNET_DNSPARSER_Record *additional_records;
+
+ /**
+ * Number of queries in the packet.
+ */
+ unsigned int num_queries;
+
+ /**
+ * Number of answers in the packet, should be 0 for queries.
+ */
+ unsigned int num_answers;
+
+ /**
+ * Number of authoritative answers in the packet, should be 0 for queries.
+ */
+ unsigned int num_authority_records;
+
+ /**
+ * Number of additional records in the packet, should be 0 for queries.
+ */
+ unsigned int num_additional_records;
+
+ /**
+ * Bitfield of DNS flags.
+ */
+ struct GNUNET_DNSPARSER_Flags flags;
+
+ /**
+ * DNS ID (to match replies to requests).
+ */
+ uint16_t id;
+
+};
+
+
+/**
+ * Parse a UDP payload of a DNS packet in to a nice struct for further
+ * processing and manipulation.
+ *
+ * @param udp_payload wire-format of the DNS packet
+ * @param udp_payload_length number of bytes in udp_payload
+ * @return NULL on error, otherwise the parsed packet
+ */
+struct GNUNET_DNSPARSER_Packet *
+GNUNET_DNSPARSER_parse (const char *udp_payload,
+ size_t udp_payload_length);
+
+
+/**
+ * Free memory taken by a packet.
+ *
+ * @param p packet to free
+ */
void
-free_parsed_dns_packet (struct dns_pkt_parsed *ppkt);
+GNUNET_DNSPARSER_free_packet (struct GNUNET_DNSPARSER_Packet *p);
+
+
+/**
+ * Given a DNS packet, generate the corresponding UDP payload.
+ *
+ * @param p packet to pack
+ * @param max maximum allowed size for the resulting UDP payload
+ * @param buf set to a buffer with the packed message
+ * @param buf_length set to the length of buf
+ * @return GNUNET_SYSERR if 'p' is invalid
+ * GNUNET_NO if 'p' was truncated (but there is still a result in 'buf')
+ * GNUNET_OK if 'p' was packed completely into '*buf'
+ */
+int
+GNUNET_DNSPARSER_pack (const struct GNUNET_DNSPARSER_Packet *p,
+ uint16_t max,
+ char **buf,
+ size_t *buf_length);
+
#endif
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