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Diffstat (limited to 'src/libknot/packet/response.h')
| -rw-r--r-- | src/libknot/packet/response.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/libknot/packet/response.h b/src/libknot/packet/response.h new file mode 100644 index 0000000..38bd9a8 --- /dev/null +++ b/src/libknot/packet/response.h @@ -0,0 +1,198 @@ +/*! + * \file response.h + * + * \author Lubos Slovak <lubos.slovak@nic.cz> + * + * \brief API for response manipulation. + * + * \addtogroup libknot + * @{ + */ +/* Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + 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 3 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, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _KNOT_response_H_ +#define _KNOT_response_H_ + +#include <stdint.h> +#include <string.h> + +#include "packet/packet.h" + +#include "dname.h" +#include "rrset.h" +#include "edns.h" + +/*! + * \brief Default maximum DNS response size + * + * This size must be supported by all servers and clients. + */ +static const short KNOT_MAX_RESPONSE_SIZE = 512; + +/*----------------------------------------------------------------------------*/ +int knot_response_init(knot_packet_t *response); + +/*! + * \brief Initializes response from the given query. + * + * Copies the header, Changes QR bit to 1, copies the Question section and + * stores pointer to the query packet structure in the response packet + * structure. + * + * \warning Never free the query packet structure after calling this function, + * it will be freed when the response structure is freed. + * + * \param response Packet structure representing the response. + * \param query Packet structure representing the query. + * + * \retval KNOT_EOK + */ +int knot_response_init_from_query(knot_packet_t *response, + knot_packet_t *query); + +/*! + * \brief Clears the response structure for reuse. + * + * After call to this function, the response will be in the same state as if + * knot_response_new() was called. The maximum wire size is retained. + * + * \param response Response structure to clear. + * + * \todo Replace the use of this function with something else maybe? + */ +void knot_response_clear(knot_packet_t *resp, int clear_question); + +/*! + * \brief Sets the OPT RR of the response. + * + * This function also allocates space for the wireformat of the response, if + * the payload in the OPT RR is larger than the current maximum size of the + * response and copies the current wireformat over to the new space. + * + * \note The contents of the OPT RR are copied. + * + * \param resp Response to set the OPT RR to. + * \param opt_rr OPT RR to set. + * + * \retval KNOT_EOK + * \retval KNOT_EBADARG + * \retval KNOT_ENOMEM + * + * \todo Needs test. + */ +int knot_response_add_opt(knot_packet_t *resp, + const knot_opt_rr_t *opt_rr, + int override_max_size); + +/*! + * \brief Adds a RRSet to the Answer section of the response. + * + * \param response Response to add the RRSet into. + * \param rrset RRSet to be added. + * \param tc Set to <> 0 if omitting this RRSet should result in the TC bit set. + * Otherwise set to 0. + * \param check_duplicates Set to <> 0 if the RRSet should not be added to the + * response in case it is already there. + * \param compr_cs Set to <> 0 if dname compression should use case sensitive + * comparation. Set to 0 otherwise. + * + * \retval KNOT_EOK if successful, or the RRSet was already in the answer. + * \retval KNOT_ENOMEM + * \retval KNOT_ESPACE + */ +int knot_response_add_rrset_answer(knot_packet_t *response, + const knot_rrset_t *rrset, int tc, + int check_duplicates, int compr_cs); + +/*! + * \brief Adds a RRSet to the Authority section of the response. + * + * \param response Response to add the RRSet into. + * \param rrset RRSet to be added. + * \param tc Set to <> 0 if omitting this RRSet should result in the TC bit set. + * Otherwise set to 0. + * \param check_duplicates Set to <> 0 if the RRSet should not be added to the + * response in case it is already there. + * \param compr_cs Set to <> 0 if dname compression should use case sensitive + * comparation. Set to 0 otherwise. + * + * \retval KNOT_EOK if successful, or the RRSet was already in the answer. + * \retval KNOT_ENOMEM + * \retval KNOT_ESPACE + */ +int knot_response_add_rrset_authority(knot_packet_t *response, + const knot_rrset_t *rrset, int tc, + int check_duplicates, int compr_cs); + +/*! + * \brief Adds a RRSet to the Additional section of the response. + * + * \param response Response to add the RRSet into. + * \param rrset RRSet to be added. + * \param tc Set to <> 0 if omitting this RRSet should result in the TC bit set. + * Otherwise set to 0. + * \param check_duplicates Set to <> 0 if the RRSet should not be added to the + * response in case it is already there. + * \param compr_cs Set to <> 0 if dname compression should use case sensitive + * comparation. Set to 0 otherwise. + * + * \retval KNOT_EOK if successful, or the RRSet was already in the answer. + * \retval KNOT_ENOMEM + * \retval KNOT_ESPACE + */ +int knot_response_add_rrset_additional(knot_packet_t *response, + const knot_rrset_t *rrset, int tc, + int check_duplicates, int compr_cs); + +/*! + * \brief Sets the RCODE of the response. + * + * \param response Response to set the RCODE in. + * \param rcode RCODE to set. + */ +void knot_response_set_rcode(knot_packet_t *response, short rcode); + +/*! + * \brief Sets the AA bit of the response to 1. + * + * \param response Response in which the AA bit should be set. + */ +void knot_response_set_aa(knot_packet_t *response); + +/*! + * \brief Sets the TC bit of the response to 1. + * + * \param response Response in which the TC bit should be set. + */ +void knot_response_set_tc(knot_packet_t *response); + +/*! + * \brief Adds NSID option to the response. + * + * \param response Response to add the NSID option into. + * \param data NSID data. + * \param length Size of NSID data in bytes. + * + * \retval KNOT_EOK + * \retval KNOT_ENOMEM + */ +int knot_response_add_nsid(knot_packet_t *response, const uint8_t *data, + uint16_t length); + +#endif /* _KNOT_response_H_ */ + +/*! @} */ |