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Diffstat (limited to 'src/libknot/packet/wire.h')
| -rw-r--r-- | src/libknot/packet/wire.h | 1053 |
1 files changed, 1053 insertions, 0 deletions
diff --git a/src/libknot/packet/wire.h b/src/libknot/packet/wire.h new file mode 100644 index 0000000..630cd83 --- /dev/null +++ b/src/libknot/packet/wire.h @@ -0,0 +1,1053 @@ +/* Copyright (C) 2024 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 <https://www.gnu.org/licenses/>. + */ + +/*! + * \file + * + * \brief Functions for manipulating and parsing raw data in DNS packets. + * + * \addtogroup wire + * @{ + */ + +#pragma once + +#include <assert.h> +#include <stdint.h> + +#include "libknot/attribute.h" +#include "libknot/wire.h" + +/*! \brief Offset of DNS header fields in wireformat. */ +enum knot_wire_offsets { + KNOT_WIRE_OFFSET_ID = 0, + KNOT_WIRE_OFFSET_FLAGS1 = 2, + KNOT_WIRE_OFFSET_FLAGS2 = 3, + KNOT_WIRE_OFFSET_QDCOUNT = 4, + KNOT_WIRE_OFFSET_ANCOUNT = 6, + KNOT_WIRE_OFFSET_NSCOUNT = 8, + KNOT_WIRE_OFFSET_ARCOUNT = 10 +}; + +/*! \brief Minimum size for some parts of the DNS packet. */ +enum knot_wire_sizes { + KNOT_WIRE_HEADER_SIZE = 12, + KNOT_WIRE_QUESTION_MIN_SIZE = 5, + KNOT_WIRE_RR_MIN_SIZE = 11, + KNOT_WIRE_MIN_PKTSIZE = 512, + KNOT_WIRE_MAX_PKTSIZE = 65535, + KNOT_WIRE_MAX_PAYLOAD = KNOT_WIRE_MAX_PKTSIZE + - KNOT_WIRE_HEADER_SIZE + - KNOT_WIRE_QUESTION_MIN_SIZE +}; + +/* + * Packet header manipulation functions. + */ + +/*! + * \brief Returns the ID from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return DNS packet ID. + */ +static inline uint16_t knot_wire_get_id(const uint8_t *packet) +{ + assert(packet); + return knot_wire_read_u16(packet + KNOT_WIRE_OFFSET_ID); +} + +/*! + * \brief Sets the ID to the wire format of the packet. + * + * \param packet Wire format of the packet. + * \param id DNS packet ID. + */ +static inline void knot_wire_set_id(uint8_t *packet, uint16_t id) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_ID, id); +} + +/*! + * \brief Returns the first byte of flags from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return First byte of DNS flags. + */ +static inline uint8_t knot_wire_get_flags1(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1); +} + +/*! + * \brief Sets the first byte of flags to the wire format of the packet. + * + * \param packet Wire format of the packet. + * \param flags1 First byte of the DNS flags. + */ +static inline uint8_t knot_wire_set_flags1(uint8_t *packet, uint8_t flags1) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1) = flags1; +} + +/*! + * \brief Returns the second byte of flags from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Second byte of DNS flags. + */ +static inline uint8_t knot_wire_get_flags2(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2); +} + +/*! + * \brief Sets the second byte of flags to the wire format of the packet. + * + * \param packet Wire format of the packet. + * \param flags2 Second byte of the DNS flags. + */ +static inline uint8_t knot_wire_set_flags2(uint8_t *packet, uint8_t flags2) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) = flags2; +} + +/*! + * \brief Returns the QDCOUNT (count of Question entries) from wire format of + * the packet. + * + * \param packet Wire format of the packet. + * + * \return QDCOUNT (count of Question entries in the packet). + */ +static inline uint16_t knot_wire_get_qdcount(const uint8_t *packet) +{ + assert(packet); + return knot_wire_read_u16(packet + KNOT_WIRE_OFFSET_QDCOUNT); +} + +/*! + * \brief Sets the QDCOUNT (count of Question entries) to wire format of the + * packet. + * + * \param packet Wire format of the packet. + * \param qdcount QDCOUNT (count of Question entries in the packet). + */ +static inline void knot_wire_set_qdcount(uint8_t *packet, uint16_t qdcount) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_QDCOUNT, qdcount); +} + +/*! + * \brief Adds to QDCOUNT. + */ +static inline void knot_wire_add_qdcount(uint8_t *packet, int16_t n) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_QDCOUNT, + knot_wire_get_qdcount(packet) + n); +} + +/*! + * \brief Returns the ANCOUNT (count of Answer entries) from wire format of + * the packet. + * + * \param packet Wire format of the packet. + * + * \return ANCOUNT (count of Answer entries in the packet). + */ +static inline uint16_t knot_wire_get_ancount(const uint8_t *packet) +{ + assert(packet); + return knot_wire_read_u16(packet + KNOT_WIRE_OFFSET_ANCOUNT); +} + +/*! + * \brief Sets the ANCOUNT (count of Answer entries) to wire format of the + * packet. + * + * \param packet Wire format of the packet. + * \param ancount ANCOUNT (count of Answer entries in the packet). + */ +static inline void knot_wire_set_ancount(uint8_t *packet, uint16_t ancount) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_ANCOUNT, ancount); +} + +/*! + * \brief Adds to ANCOUNT. + */ +static inline void knot_wire_add_ancount(uint8_t *packet, int16_t n) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_ANCOUNT, + knot_wire_get_ancount(packet) + n); +} + +/*! + * \brief Returns the NSCOUNT (count of Authority entries) from wire format of + * the packet. + * + * \param packet Wire format of the packet. + * + * \return NSCOUNT (count of Authority entries in the packet). + */ +static inline uint16_t knot_wire_get_nscount(const uint8_t *packet) +{ + assert(packet); + return knot_wire_read_u16(packet + KNOT_WIRE_OFFSET_NSCOUNT); +} + +/*! + * \brief Sets the NSCOUNT (count of Authority entries) to wire format of the + * packet. + * + * \param packet Wire format of the packet. + * \param nscount NSCOUNT (count of Authority entries in the packet). + */ +static inline void knot_wire_set_nscount(uint8_t *packet, uint16_t nscount) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_NSCOUNT, nscount); +} + +/*! + * \brief Adds to NSCOUNT. + */ +static inline void knot_wire_add_nscount(uint8_t *packet, int16_t n) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_NSCOUNT, + knot_wire_get_nscount(packet) + n); +} + +/*! + * \brief Returns the ARCOUNT (count of Additional entries) from wire format of + * the packet. + * + * \param packet Wire format of the packet. + * + * \return ARCOUNT (count of Additional entries in the packet). + */ +static inline uint16_t knot_wire_get_arcount(const uint8_t *packet) +{ + assert(packet); + return knot_wire_read_u16(packet + KNOT_WIRE_OFFSET_ARCOUNT); +} + +/*! + * \brief Sets the ARCOUNT (count of Additional entries) to wire format of the + * packet. + * + * \param packet Wire format of the packet. + * \param arcount ARCOUNT (count of Additional entries in the packet). + */ +static inline void knot_wire_set_arcount(uint8_t *packet, uint16_t arcount) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_ARCOUNT, arcount); +} + +/*! + * \brief Adds to ARCOUNT. + */ +static inline void knot_wire_add_arcount(uint8_t *packet, int16_t n) +{ + assert(packet); + knot_wire_write_u16(packet + KNOT_WIRE_OFFSET_ARCOUNT, + knot_wire_get_arcount(packet) + n); +} + +/* + * Packet header flags manipulation functions. + */ +/*! \brief Constants for DNS header flags in the first flags byte. */ +enum knot_wire_flags1_consts { + KNOT_WIRE_RD_MASK = (uint8_t)0x01U, /*!< RD bit mask. */ + KNOT_WIRE_RD_SHIFT = 0, /*!< RD bit shift. */ + KNOT_WIRE_TC_MASK = (uint8_t)0x02U, /*!< TC bit mask. */ + KNOT_WIRE_TC_SHIFT = 1, /*!< TC bit shift. */ + KNOT_WIRE_AA_MASK = (uint8_t)0x04U, /*!< AA bit mask. */ + KNOT_WIRE_AA_SHIFT = 2, /*!< AA bit shift. */ + KNOT_WIRE_OPCODE_MASK = (uint8_t)0x78U, /*!< OPCODE mask. */ + KNOT_WIRE_OPCODE_SHIFT = 3, /*!< OPCODE shift. */ + KNOT_WIRE_QR_MASK = (uint8_t)0x80U, /*!< QR bit mask. */ + KNOT_WIRE_QR_SHIFT = 7 /*!< QR bit shift. */ +}; + +/*! \brief Constants for DNS header flags in the second flags byte. */ +enum knot_wire_flags2_consts { + KNOT_WIRE_RCODE_MASK = (uint8_t)0x0fU, /*!< RCODE mask. */ + KNOT_WIRE_RCODE_SHIFT = 0, /*!< RCODE shift. */ + KNOT_WIRE_CD_MASK = (uint8_t)0x10U, /*!< CD bit mask. */ + KNOT_WIRE_CD_SHIFT = 4, /*!< CD bit shift. */ + KNOT_WIRE_AD_MASK = (uint8_t)0x20U, /*!< AD bit mask. */ + KNOT_WIRE_AD_SHIFT = 5, /*!< AD bit shift. */ + KNOT_WIRE_Z_MASK = (uint8_t)0x40U, /*!< Zero bit mask. */ + KNOT_WIRE_Z_SHIFT = 6, /*!< Zero bit shift. */ + KNOT_WIRE_RA_MASK = (uint8_t)0x80U, /*!< RA bit mask. */ + KNOT_WIRE_RA_SHIFT = 7 /*!< RA bit shift. */ +}; + +/* + * Functions for getting / setting / clearing flags and codes directly in packet + */ + +/*! + * \brief Returns the RD bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the RD bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_rd(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1) & KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Sets the RD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_rd(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) |= KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Clears the RD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_rd(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) &= ~KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Returns the TC bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the TC bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_tc(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1) & KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Sets the TC bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_tc(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) |= KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Clears the TC bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_tc(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) &= ~KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Returns the AA bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the AA bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_aa(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1) & KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Sets the AA bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_aa(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) |= KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Clears the AA bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_aa(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) &= ~KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Returns the OPCODE from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return OPCODE of the packet. + */ +static inline uint8_t knot_wire_get_opcode(const uint8_t *packet) +{ + assert(packet); + return (*(packet + KNOT_WIRE_OFFSET_FLAGS1) + & KNOT_WIRE_OPCODE_MASK) >> KNOT_WIRE_OPCODE_SHIFT; +} + +/*! + * \brief Sets the OPCODE in the wire format of the packet. + * + * \param packet Wire format of the packet. + * \param opcode OPCODE to set. + */ +static inline void knot_wire_set_opcode(uint8_t *packet, short opcode) +{ + assert(packet); + uint8_t *flags1 = packet + KNOT_WIRE_OFFSET_FLAGS1; + *flags1 = (*flags1 & ~KNOT_WIRE_OPCODE_MASK) + | ((opcode) << KNOT_WIRE_OPCODE_SHIFT); +} + +/*! + * \brief Returns the QR bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Nonzero for responses and zero for queries. + */ +static inline uint8_t knot_wire_get_qr(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS1) & KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Sets the QR bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_qr(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) |= KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Clears the QR bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_qr(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS1) &= ~KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Returns the RCODE from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return RCODE of the packet. + */ +static inline uint8_t knot_wire_get_rcode(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) + & KNOT_WIRE_RCODE_MASK; +} + +/*! + * \brief Sets the RCODE in the wire format of the packet. + * + * \param packet Wire format of the packet. + * \param rcode RCODE to set. + */ +static inline void knot_wire_set_rcode(uint8_t *packet, short rcode) +{ + assert(packet); + uint8_t *flags2 = packet + KNOT_WIRE_OFFSET_FLAGS2; + *flags2 = (*flags2 & ~KNOT_WIRE_RCODE_MASK) | (rcode); +} + +/*! + * \brief Returns the CD bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the CD bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_cd(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) & KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Sets the CD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_cd(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) |= KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Clears the CD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_cd(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) &= ~KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Returns the AD bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the AD bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_ad(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) & KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Sets the AD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_ad(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) |= KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Clears the AD bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_ad(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) &= ~KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Returns the Zero bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the Zero bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_z(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) & KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Sets the Zero bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_z(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) |= KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Clears the Zero bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_z(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) &= ~KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Returns the RA bit from wire format of the packet. + * + * \param packet Wire format of the packet. + * + * \return Flags with only the RA bit according to its setting in the packet. + */ +static inline uint8_t knot_wire_get_ra(const uint8_t *packet) +{ + assert(packet); + return *(packet + KNOT_WIRE_OFFSET_FLAGS2) & KNOT_WIRE_RA_MASK; +} + +/*! + * \brief Sets the RA bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_set_ra(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) |= KNOT_WIRE_RA_MASK; +} + +/*! + * \brief Clears the RA bit in the wire format of the packet. + * + * \param packet Wire format of the packet. + */ +static inline void knot_wire_clear_ra(uint8_t *packet) +{ + assert(packet); + *(packet + KNOT_WIRE_OFFSET_FLAGS2) &= ~KNOT_WIRE_RA_MASK; +} + +/* + * Functions for getting / setting / clearing flags in flags variable + */ + +/*! + * \brief Returns the RD bit from the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * + * \return Flags byte with only the RD bit according to its setting in + * \a flags1. + */ +static inline uint8_t knot_wire_flags_get_rd(uint8_t flags1) +{ + return flags1 & KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Sets the RD bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_set_rd(uint8_t *flags1) +{ + assert(flags1); + *flags1 |= KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Clears the RD bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_rd(uint8_t *flags1) +{ + assert(flags1); + *flags1 &= ~KNOT_WIRE_RD_MASK; +} + +/*! + * \brief Returns the TC bit from the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * + * \return Flags byte with only the TC bit according to its setting in + * \a flags1. + */ +static inline uint8_t knot_wire_flags_get_tc(uint8_t flags1) +{ + return flags1 & KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Sets the TC bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_set_tc(uint8_t *flags1) +{ + assert(flags1); + *flags1 |= KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Clears the TC bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_tc(uint8_t *flags1) +{ + assert(flags1); + *flags1 &= ~KNOT_WIRE_TC_MASK; +} + +/*! + * \brief Returns the AA bit from the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * + * \return Flags byte with only the AA bit according to its setting in + * \a flags1. + */ +static inline uint8_t knot_wire_flags_get_aa(uint8_t flags1) +{ + return flags1 & KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Sets the AA bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_set_aa(uint8_t *flags1) +{ + assert(flags1); + *flags1 |= KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Clears the AA bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_aa(uint8_t *flags1) +{ + assert(flags1); + *flags1 &= ~KNOT_WIRE_AA_MASK; +} + +/*! + * \brief Returns the OPCODE from the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * + * \return OPCODE + */ +static inline uint8_t knot_wire_flags_get_opcode(uint8_t flags1) +{ + return (flags1 & KNOT_WIRE_OPCODE_MASK) + >> KNOT_WIRE_OPCODE_SHIFT; +} + +/*! + * \brief Sets the OPCODE in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * \param opcode OPCODE to set. + */ +static inline void knot_wire_flags_set_opcode(uint8_t *flags1, short opcode) +{ + assert(flags1); + *flags1 = (*flags1 & ~KNOT_WIRE_OPCODE_MASK) + | ((opcode) << KNOT_WIRE_OPCODE_SHIFT); +} + +/*! + * \brief Returns the QR bit from the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + * + * \return Flags byte with only the QR bit according to its setting in + * \a flags1. + */ +static inline uint8_t knot_wire_flags_get_qr(uint8_t flags1) +{ + return flags1 & KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Sets the QR bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_set_qr(uint8_t *flags1) +{ + assert(flags1); + *flags1 |= KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Clears the QR bit in the first byte of flags. + * + * \param flags1 First byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_qr(uint8_t *flags1) +{ + assert(flags1); + *flags1 &= ~KNOT_WIRE_QR_MASK; +} + +/*! + * \brief Returns the RCODE from the second byte of flags. + * + * \param flags2 First byte of DNS header flags. + * + * \return RCODE + */ +static inline uint8_t knot_wire_flags_get_rcode(uint8_t flags2) +{ + return flags2 & KNOT_WIRE_RCODE_MASK; +} + +/*! + * \brief Sets the RCODE in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + * \param rcode RCODE to set. + */ +static inline void knot_wire_flags_set_rcode(uint8_t *flags2, short rcode) +{ + assert(flags2); + *flags2 = (*flags2 & ~KNOT_WIRE_RCODE_MASK) | (rcode); +} + +/*! + * \brief Returns the CD bit from the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + * + * \return Flags byte with only the CD bit according to its setting in + * \a flags2. + */ +static inline uint8_t knot_wire_flags_get_cd(uint8_t flags2) +{ + return flags2 & KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Sets the CD bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_set_cd(uint8_t *flags2) +{ + assert(flags2); + *flags2 |= KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Clears the CD bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_cd(uint8_t *flags2) +{ + assert(flags2); + *flags2 &= ~KNOT_WIRE_CD_MASK; +} + +/*! + * \brief Returns the AD bit from the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + * + * \return Flags byte with only the AD bit according to its setting in + * \a flags2. + */ +static inline uint8_t knot_wire_flags_get_ad(uint8_t flags2) +{ + return flags2 & KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Sets the AD bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_set_ad(uint8_t *flags2) +{ + assert(flags2); + *flags2 |= KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Clears the AD bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_ad(uint8_t *flags2) +{ + assert(flags2); + *flags2 &= ~KNOT_WIRE_AD_MASK; +} + +/*! + * \brief Returns the Zero bit from the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + * + * \return Flags byte with only the Zero bit according to its setting in + * \a flags2. + */ +static inline uint8_t knot_wire_flags_get_z(uint8_t flags2) +{ + return flags2 & KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Sets the Zero bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_set_z(uint8_t *flags2) +{ + assert(flags2); + *flags2 |= KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Clears the Zero bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_z(uint8_t *flags2) +{ + assert(flags2); + *flags2 &= ~KNOT_WIRE_Z_MASK; +} + +/*! + * \brief Returns the RA bit from the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + * + * \return Flags byte with only the RA bit according to its setting in + * \a flags2. + */ +static inline uint8_t knot_wire_flags_get_ra(uint8_t flags2) +{ + return flags2 & KNOT_WIRE_RA_MASK; +} + +/*! + * \brief Sets the RA bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_set_ra(uint8_t *flags2) +{ + assert(flags2); + *flags2 |= KNOT_WIRE_RA_MASK; +} + +/*! + * \brief Clears the RA bit in the second byte of flags. + * + * \param flags2 Second byte of DNS header flags. + */ +static inline void knot_wire_flags_clear_ra(uint8_t *flags2) +{ + assert(flags2); + *flags2 &= ~KNOT_WIRE_RA_MASK; +} + +/* + * Pointer manipulation + */ + +enum knot_wire_pointer_consts { + /*! \brief DNS packet pointer designation (first two bits set to 1). */ + KNOT_WIRE_PTR = (uint8_t)0xC0, + /*! \brief DNS packet minimal pointer (KNOT_WIRE_PTR + 1 zero byte). */ + KNOT_WIRE_PTR_BASE = (uint16_t)0xC000, + /*! \brief DNS packet maximal offset (KNOT_WIRE_BASE complement). */ + KNOT_WIRE_PTR_MAX = (uint16_t)0x3FFF +}; + +static inline int knot_wire_is_pointer(const uint8_t *pos) +{ + return pos && ((pos[0] & KNOT_WIRE_PTR) == KNOT_WIRE_PTR); +} + +/*! + * \brief Creates a DNS packet pointer and stores it in wire format. + * + * \param wire Beginning of the packet wire. + * \param pos Position where tu put the pointer. + * \param ptr Relative position of the item to which the pointer should point in + * the wire format of the packet. + */ +static inline void knot_wire_put_pointer(const uint8_t *wire, uint8_t *pos, uint16_t ptr) +{ + assert(wire + ptr < pos); + knot_wire_write_u16(pos, ptr); // Write pointer offset. + assert((pos[0] & KNOT_WIRE_PTR) == 0); // Check for maximal offset. + pos[0] |= KNOT_WIRE_PTR; // Add pointer mark. +} + +static inline uint16_t knot_wire_get_pointer(const uint8_t *pos) +{ + assert(knot_wire_is_pointer(pos)); // Check pointer. + return (knot_wire_read_u16(pos) - KNOT_WIRE_PTR_BASE); // Return offset. +} + +_pure_ _mustcheck_ +static inline const uint8_t *knot_wire_seek_label(const uint8_t *lp, const uint8_t *wire) +{ + while (knot_wire_is_pointer(lp)) { + if (!wire) { + return NULL; + } + const uint8_t *new_lp = wire + knot_wire_get_pointer(lp); + if (new_lp >= lp) { + assert(0); + return NULL; + } + lp = new_lp; + } + return lp; +} + +_pure_ _mustcheck_ +static inline const uint8_t *knot_wire_next_label(const uint8_t *lp, const uint8_t *wire) +{ + if (!lp || !lp[0]) /* No label after final label. */ + return NULL; + return knot_wire_seek_label(lp + (lp[0] + sizeof(uint8_t)), wire); +} + +/*! @} */ |