diff options
Diffstat (limited to 'external/unbound/sldns/sbuffer.h')
| -rw-r--r-- | external/unbound/sldns/sbuffer.h | 114 |
1 files changed, 106 insertions, 8 deletions
diff --git a/external/unbound/sldns/sbuffer.h b/external/unbound/sldns/sbuffer.h index 3ce874fc7..d1aadf8a1 100644 --- a/external/unbound/sldns/sbuffer.h +++ b/external/unbound/sldns/sbuffer.h @@ -87,6 +87,19 @@ sldns_write_uint32(void *dst, uint32_t data) } +INLINE void +sldns_write_uint48(void *dst, uint64_t data) +{ + uint8_t *p = (uint8_t *) dst; + p[0] = (uint8_t) ((data >> 40) & 0xff); + p[1] = (uint8_t) ((data >> 32) & 0xff); + p[2] = (uint8_t) ((data >> 24) & 0xff); + p[3] = (uint8_t) ((data >> 16) & 0xff); + p[4] = (uint8_t) ((data >> 8) & 0xff); + p[5] = (uint8_t) (data & 0xff); +} + + /** * \file sbuffer.h * @@ -117,6 +130,17 @@ struct sldns_buffer /** If the buffer is fixed it cannot be resized */ unsigned _fixed : 1; + /** If the buffer is vfixed, no more than capacity bytes willl be + * written to _data, however the _position counter will be updated + * with the amount that would have been written in consecutive + * writes. This allows for a modus operandi in which a sequence is + * written on a fixed capacity buffer (perhaps with _data on stack). + * When everything could be written, then the _data is immediately + * usable, if not, then a buffer could be allocated sized precisely + * to fit the data for a second attempt. + */ + unsigned _vfixed : 1; + /** The current state of the buffer. If writing to the buffer fails * for any reason, this value is changed. This way, you can perform * multiple writes in sequence and check for success afterwards. */ @@ -134,9 +158,9 @@ INLINE void sldns_buffer_invariant(sldns_buffer *buffer) { assert(buffer != NULL); - assert(buffer->_position <= buffer->_limit); + assert(buffer->_position <= buffer->_limit || buffer->_vfixed); assert(buffer->_limit <= buffer->_capacity); - assert(buffer->_data != NULL); + assert(buffer->_data != NULL || (buffer->_vfixed && buffer->_capacity == 0)); } #endif @@ -169,6 +193,19 @@ void sldns_buffer_new_frm_data(sldns_buffer *buffer, void *data, size_t size); void sldns_buffer_init_frm_data(sldns_buffer *buffer, void *data, size_t size); /** + * Setup a buffer with the data pointed to. No data copied, no memory allocs. + * The buffer is "virtually" fixed. Writes beyond size (the capacity) will + * only update position, but no data will be written beyond capacity. This + * allows to determine how big the buffer should have been to contain all the + * written data, by looking at the position with sldns_buffer_position(), + * similarly to the return value of POSIX's snprintf. + * \param[in] buffer pointer to the buffer to put the data in + * \param[in] data the data to encapsulate in the buffer + * \param[in] size the size of the data + */ +void sldns_buffer_init_vfixed_frm_data(sldns_buffer *buffer, void *data, size_t size); + +/** * clears the buffer and make it ready for writing. The buffer's limit * is set to the capacity and the position is set to 0. * \param[in] buffer the buffer to clear @@ -231,7 +268,7 @@ sldns_buffer_position(sldns_buffer *buffer) INLINE void sldns_buffer_set_position(sldns_buffer *buffer, size_t mark) { - assert(mark <= buffer->_limit); + assert(mark <= buffer->_limit || buffer->_vfixed); buffer->_position = mark; } @@ -245,7 +282,7 @@ sldns_buffer_set_position(sldns_buffer *buffer, size_t mark) INLINE void sldns_buffer_skip(sldns_buffer *buffer, ssize_t count) { - assert(buffer->_position + count <= buffer->_limit); + assert(buffer->_position + count <= buffer->_limit || buffer->_vfixed); buffer->_position += count; } @@ -317,7 +354,7 @@ int sldns_buffer_reserve(sldns_buffer *buffer, size_t amount); INLINE uint8_t * sldns_buffer_at(const sldns_buffer *buffer, size_t at) { - assert(at <= buffer->_limit); + assert(at <= buffer->_limit || buffer->_vfixed); return buffer->_data + at; } @@ -367,8 +404,8 @@ INLINE size_t sldns_buffer_remaining_at(sldns_buffer *buffer, size_t at) { sldns_buffer_invariant(buffer); - assert(at <= buffer->_limit); - return buffer->_limit - at; + assert(at <= buffer->_limit || buffer->_vfixed); + return at < buffer->_limit ? buffer->_limit - at : 0; } /** @@ -420,11 +457,43 @@ sldns_buffer_available(sldns_buffer *buffer, size_t count) INLINE void sldns_buffer_write_at(sldns_buffer *buffer, size_t at, const void *data, size_t count) { - assert(sldns_buffer_available_at(buffer, at, count)); + if (!buffer->_vfixed) + assert(sldns_buffer_available_at(buffer, at, count)); + else if (sldns_buffer_remaining_at(buffer, at) == 0) + return; + else if (count > sldns_buffer_remaining_at(buffer, at)) { + memcpy(buffer->_data + at, data, + sldns_buffer_remaining_at(buffer, at)); + return; + } memcpy(buffer->_data + at, data, count); } /** + * set the given byte to the buffer at the specified position + * \param[in] buffer the buffer + * \param[in] at the position (in number of bytes) to write the data at + * \param[in] c the byte to set to the buffer + * \param[in] count the number of bytes of bytes to write + */ + +INLINE void +sldns_buffer_set_at(sldns_buffer *buffer, size_t at, int c, size_t count) +{ + if (!buffer->_vfixed) + assert(sldns_buffer_available_at(buffer, at, count)); + else if (sldns_buffer_remaining_at(buffer, at) == 0) + return; + else if (count > sldns_buffer_remaining_at(buffer, at)) { + memset(buffer->_data + at, c, + sldns_buffer_remaining_at(buffer, at)); + return; + } + memset(buffer->_data + at, c, count); +} + + +/** * writes count bytes of data to the current position of the buffer * \param[in] buffer the buffer * \param[in] data the data to write @@ -469,6 +538,7 @@ sldns_buffer_write_string(sldns_buffer *buffer, const char *str) INLINE void sldns_buffer_write_u8_at(sldns_buffer *buffer, size_t at, uint8_t data) { + if (buffer->_vfixed && at + sizeof(data) > buffer->_limit) return; assert(sldns_buffer_available_at(buffer, at, sizeof(data))); buffer->_data[at] = data; } @@ -494,6 +564,7 @@ sldns_buffer_write_u8(sldns_buffer *buffer, uint8_t data) INLINE void sldns_buffer_write_u16_at(sldns_buffer *buffer, size_t at, uint16_t data) { + if (buffer->_vfixed && at + sizeof(data) > buffer->_limit) return; assert(sldns_buffer_available_at(buffer, at, sizeof(data))); sldns_write_uint16(buffer->_data + at, data); } @@ -519,11 +590,26 @@ sldns_buffer_write_u16(sldns_buffer *buffer, uint16_t data) INLINE void sldns_buffer_write_u32_at(sldns_buffer *buffer, size_t at, uint32_t data) { + if (buffer->_vfixed && at + sizeof(data) > buffer->_limit) return; assert(sldns_buffer_available_at(buffer, at, sizeof(data))); sldns_write_uint32(buffer->_data + at, data); } /** + * writes the given 6 byte integer at the given position in the buffer + * \param[in] buffer the buffer + * \param[in] at the position in the buffer + * \param[in] data the (lower) 48 bits to write + */ +INLINE void +sldns_buffer_write_u48_at(sldns_buffer *buffer, size_t at, uint64_t data) +{ + if (buffer->_vfixed && at + 6 > buffer->_limit) return; + assert(sldns_buffer_available_at(buffer, at, 6)); + sldns_write_uint48(buffer->_data + at, data); +} + +/** * writes the given 4 byte integer at the current position in the buffer * \param[in] buffer the buffer * \param[in] data the 32 bits to write @@ -536,6 +622,18 @@ sldns_buffer_write_u32(sldns_buffer *buffer, uint32_t data) } /** + * writes the given 6 byte integer at the current position in the buffer + * \param[in] buffer the buffer + * \param[in] data the 48 bits to write + */ +INLINE void +sldns_buffer_write_u48(sldns_buffer *buffer, uint64_t data) +{ + sldns_buffer_write_u48_at(buffer, buffer->_position, data); + buffer->_position += 6; +} + +/** * copies count bytes of data at the given position to the given data-array * \param[in] buffer the buffer * \param[in] at the position in the buffer to start |