nbo.h

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#pragma once
/*
 *  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 St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/** Structures and functions for converting integers to/from network byte order
 *
 * @file src/lib/util/nbo.h
 *
 * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2022 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
RCSIDH(nbo_h, "$Id: 627eef671c7cfdd0e2cd2a68446f63a52d19df78 $")
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <freeradius-devel/util/misc.h>
 
/** Write out an unsigned 16bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_uint16(uint8_t out[static sizeof(uint16_t)], uint16_t num)
{
        out[0] = (num >> 8) & 0xff;
        out[1] = num & 0xff;
}
 
/** Write out an unsigned 24bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_uint24(uint8_t out[static 3], uint32_t num)
{
        out[0] = (num >> 16) & 0xff;
        out[1] = (num >> 8) & 0xff;
        out[2] = num & 0xff;
}
 
/** Write out an unsigned 32bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_uint32(uint8_t out[static sizeof(uint32_t)], uint32_t num)
{
        fr_nbo_from_uint16(out, (uint16_t) (num >> 16));
        fr_nbo_from_uint16(out + sizeof(uint16_t), (uint16_t) num);
}
 
/** Write out an unsigned 64bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_uint64(uint8_t out[static sizeof(uint64_t)], uint64_t num)
{
        fr_nbo_from_uint32(out, (uint32_t)(num >> 32));
        fr_nbo_from_uint32(out + sizeof(uint32_t), (uint32_t)num);
}
 
/** Write out an signed 16bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_int16(uint8_t out[static sizeof(int16_t)], int16_t num)
{
        out[0] = (num >> 8) & 0xff;
        out[1] = num & 0xff;
}
 
/** Write out an signed 32bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_int32(uint8_t out[static sizeof(int32_t)], int32_t num)
{
        fr_nbo_from_uint16(out, (int16_t) (num >> 16));
        fr_nbo_from_uint16(out + sizeof(int16_t), (int16_t) num);
}
 
/** Write out an signed 64bit integer in wire format (big endian)
 *
 * @param[out] out      Where to write the integer.
 * @param[in] num       to encode.
 */
static inline void fr_nbo_from_int64(uint8_t out[static sizeof(uint64_t)], uint64_t num)
{
        fr_nbo_from_uint32(out, (int32_t)(num >> 32));
        fr_nbo_from_uint32(out + sizeof(int32_t), (int32_t)num);
}
 
/** Write out an unsigned 64bit integer in wire format using the fewest bytes possible
 *
 * @param[out] out      Where to write big endian encoding of num.
 *                      Should be at least 8 bytes.
 * @param[in] num       Number to encode.
 * @return the number of bytes written to out.
 */
static inline size_t fr_nbo_from_uint64v(uint8_t out[static sizeof(uint64_t)], uint64_t num)
{
        size_t ret;
        uint8_t swapped[sizeof(uint64_t)];
 
        ret = ROUND_UP_DIV((size_t)fr_high_bit_pos(num | 0x80), 8);
#ifdef __COVERITY__
        /*
         * Coverity doesn't realize that the fr_high_bit_pos() call will always
         * return a value between 1 and 8 inclusive, the former thanks to the
         * "| 0x80". and this function doesn't specify an error return value,
         * so we use a Coverity-only assert.
         */
        if (!fr_cond_assert((ret >= 1) && (ret <= 8))) return 1;
#endif
 
        fr_nbo_from_uint64(swapped, num);
        memcpy(out, (swapped + (sizeof(uint64_t) - ret)), ret); /* aligned */
 
        return ret;
}
 
/** Read an unsigned 16bit integer from wire format (big endian)
 *
 * @param[in] data      To convert to a 16bit unsigned integer of native endianness.
 * @return a 16 bit unsigned integer of native endianness.
 */
/* coverity[-taint_source : arg-0] */
static inline uint16_t fr_nbo_to_uint16(uint8_t const data[static sizeof(uint16_t)])
{
        return (((uint16_t)data[0]) << 8) | data[1];
}
 
/** Read an unsigned 24bit integer from wire format (big endian)
 *
 * @param[in] data      To convert to a 24bit unsigned integer of native endianness.
 * @return a 24 bit unsigned integer of native endianness.
 */
/* coverity[-taint_source : arg-0] */
static inline uint32_t fr_nbo_to_uint24(uint8_t const data[static 3])
{
        return (((uint32_t)data[0]) << 16) | (((uint32_t)data[1]) << 8) | data[2];
}
 
/** Read an unsigned 32bit integer from wire format (big endian)
 *
 * @param[in] data      To convert to a 32bit unsigned integer of native endianness.
 * @return a 32 bit unsigned integer of native endianness.
 */
static inline uint32_t fr_nbo_to_uint32(uint8_t const data[static sizeof(uint32_t)])
{
        return ((uint32_t)fr_nbo_to_uint16(data) << 16) | fr_nbo_to_uint16(data + sizeof(uint16_t));
}
 
/** Read an unsigned 64bit integer from wire format (big endian)
 *
 * @param[in] data      To convert to a 64bit unsigned integer of native endianness.
 * @return a 64 bit unsigned integer of native endianness.
 */
static inline uint64_t fr_nbo_to_uint64(uint8_t const data[static sizeof(uint64_t)])
{
        return ((uint64_t)fr_nbo_to_uint32(data) << 32) | fr_nbo_to_uint32(data + sizeof(uint32_t));
}
 
/*
 * To get signed integers, simply cast.
 */
#define fr_nbo_to_int16(_x)     ((int16_t) fr_nbo_to_uint16(_x))
#define fr_nbo_to_int32(_x)     ((int32_t) fr_nbo_to_uint32(_x))
#define fr_nbo_to_int64(_x)     ((int64_t) fr_nbo_to_uint64(_x))
 
 
/** Read an unsigned 64bit integer from wire format (big endian) with a variable length encoding
 *
 * @param[in] data      Buffer containing the number.
 * @param[in] data_len  Length of number.
 * @return a 64 bit unsigned integer of native endianness.
 */
static inline uint64_t fr_nbo_to_uint64v(uint8_t const *data, size_t data_len)
{
        uint64_t num = 0;
        uint64_t nbo;
 
        if (unlikely(data_len > sizeof(uint64_t))) return 0;
 
        /*
         *      Copy at an offset into memory
         *      allocated for the uin64_t
         */
        memcpy(((uint8_t *)&num) + (sizeof(uint64_t) - data_len), data, data_len);      /* aligned */
        fr_nbo_from_uint64((uint8_t *)&nbo, num);
 
        return nbo;
}
 
static inline uint64_t fr_nbo_to_int64v(uint8_t const *data, size_t data_len)
{
        int64_t num = 0;
        uint64_t nbo;
 
        if (unlikely(data_len > sizeof(uint64_t))) return 0;
 
        /*
         *      Copy at an offset into memory
         *      allocated for the uin64_t
         */
        memcpy(((uint8_t *)&num) + (sizeof(uint64_t) - data_len), data, data_len);      /* aligned */
        if (*data & 0x80) memset(((uint8_t *)&num) + data_len, 0xff, sizeof(num) - data_len);
 
        fr_nbo_from_uint64((uint8_t *)&nbo, num);
 
        return nbo;
}
 
/** Convert bits (as in prefix length) to bytes, rounding up.
 *
 * @param bits number of bits in the prefix
 * @return number of bytes taken to store the prefix
 */
static inline unsigned int fr_bytes_from_bits(unsigned int bits)
{
        return (bits + 7) >> 3;
}
 
#ifdef __cplusplus
}
#endif