diff options
Diffstat (limited to 'ldns/sbuffer.h')
| -rw-r--r-- | ldns/sbuffer.h | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/ldns/sbuffer.h b/ldns/sbuffer.h new file mode 100644 index 000000000000..2436763d3ea9 --- /dev/null +++ b/ldns/sbuffer.h @@ -0,0 +1,706 @@ +/* + * buffer.h -- generic memory buffer. + * + * Copyright (c) 2005-2008, NLnet Labs. All rights reserved. + * + * See LICENSE for the license. + * + * + * The buffer module implements a generic buffer. The API is based on + * the java.nio.Buffer interface. + */ + +#ifndef LDNS_SBUFFER_H +#define LDNS_SBUFFER_H + +#ifdef __cplusplus +extern "C" { +#endif + +#ifdef S_SPLINT_S +# define INLINE +#else +# ifdef SWIG +# define INLINE static +# else +# define INLINE static inline +# endif +#endif + +/* + * Copy data allowing for unaligned accesses in network byte order + * (big endian). + */ +INLINE uint16_t +sldns_read_uint16(const void *src) +{ +#ifdef ALLOW_UNALIGNED_ACCESSES + return ntohs(*(uint16_t *) src); +#else + uint8_t *p = (uint8_t *) src; + return ((uint16_t) p[0] << 8) | (uint16_t) p[1]; +#endif +} + +INLINE uint32_t +sldns_read_uint32(const void *src) +{ +#ifdef ALLOW_UNALIGNED_ACCESSES + return ntohl(*(uint32_t *) src); +#else + uint8_t *p = (uint8_t *) src; + return ( ((uint32_t) p[0] << 24) + | ((uint32_t) p[1] << 16) + | ((uint32_t) p[2] << 8) + | (uint32_t) p[3]); +#endif +} + +/* + * Copy data allowing for unaligned accesses in network byte order + * (big endian). + */ +INLINE void +sldns_write_uint16(void *dst, uint16_t data) +{ +#ifdef ALLOW_UNALIGNED_ACCESSES + * (uint16_t *) dst = htons(data); +#else + uint8_t *p = (uint8_t *) dst; + p[0] = (uint8_t) ((data >> 8) & 0xff); + p[1] = (uint8_t) (data & 0xff); +#endif +} + +INLINE void +sldns_write_uint32(void *dst, uint32_t data) +{ +#ifdef ALLOW_UNALIGNED_ACCESSES + * (uint32_t *) dst = htonl(data); +#else + uint8_t *p = (uint8_t *) dst; + p[0] = (uint8_t) ((data >> 24) & 0xff); + p[1] = (uint8_t) ((data >> 16) & 0xff); + p[2] = (uint8_t) ((data >> 8) & 0xff); + p[3] = (uint8_t) (data & 0xff); +#endif +} + + +/** + * \file sbuffer.h + * + * This file contains the definition of sldns_buffer, and functions to manipulate those. + */ + +/** + * implementation of buffers to ease operations + * + * sldns_buffers can contain arbitrary information, per octet. You can write + * to the current end of a buffer, read from the current position, and + * access any data within it. + */ +struct sldns_buffer +{ + /** The current position used for reading/writing */ + size_t _position; + + /** The read/write limit */ + size_t _limit; + + /** The amount of data the buffer can contain */ + size_t _capacity; + + /** The data contained in the buffer */ + uint8_t *_data; + + /** If the buffer is fixed it cannot be resized */ + unsigned _fixed : 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. */ + unsigned _status_err : 1; +}; +typedef struct sldns_buffer sldns_buffer; + +#ifdef NDEBUG +INLINE void +sldns_buffer_invariant(sldns_buffer *ATTR_UNUSED(buffer)) +{ +} +#else +INLINE void +sldns_buffer_invariant(sldns_buffer *buffer) +{ + assert(buffer != NULL); + assert(buffer->_position <= buffer->_limit); + assert(buffer->_limit <= buffer->_capacity); + assert(buffer->_data != NULL); +} +#endif + +/** + * creates a new buffer with the specified capacity. + * + * \param[in] capacity the size (in bytes) to allocate for the buffer + * \return the created buffer + */ +sldns_buffer *sldns_buffer_new(size_t capacity); + +/** + * creates a buffer with the specified data. The data IS copied + * and MEMORY allocations are done. The buffer is not fixed and can + * be resized using buffer_reserve(). + * + * \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_new_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 fixed. + * \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_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 + */ +INLINE void sldns_buffer_clear(sldns_buffer *buffer) +{ + sldns_buffer_invariant(buffer); + + /* reset status here? */ + + buffer->_position = 0; + buffer->_limit = buffer->_capacity; +} + +/** + * makes the buffer ready for reading the data that has been written to + * the buffer. The buffer's limit is set to the current position and + * the position is set to 0. + * + * \param[in] buffer the buffer to flip + * \return void + */ +INLINE void sldns_buffer_flip(sldns_buffer *buffer) +{ + sldns_buffer_invariant(buffer); + + buffer->_limit = buffer->_position; + buffer->_position = 0; +} + +/** + * make the buffer ready for re-reading the data. The buffer's + * position is reset to 0. + * \param[in] buffer the buffer to rewind + */ +INLINE void sldns_buffer_rewind(sldns_buffer *buffer) +{ + sldns_buffer_invariant(buffer); + + buffer->_position = 0; +} + +/** + * returns the current position in the buffer (as a number of bytes) + * \param[in] buffer the buffer + * \return the current position + */ +INLINE size_t +sldns_buffer_position(sldns_buffer *buffer) +{ + return buffer->_position; +} + +/** + * sets the buffer's position to MARK. The position must be less than + * or equal to the buffer's limit. + * \param[in] buffer the buffer + * \param[in] mark the mark to use + */ +INLINE void +sldns_buffer_set_position(sldns_buffer *buffer, size_t mark) +{ + assert(mark <= buffer->_limit); + buffer->_position = mark; +} + +/** + * changes the buffer's position by COUNT bytes. The position must not + * be moved behind the buffer's limit or before the beginning of the + * buffer. + * \param[in] buffer the buffer + * \param[in] count the count to use + */ +INLINE void +sldns_buffer_skip(sldns_buffer *buffer, ssize_t count) +{ + assert(buffer->_position + count <= buffer->_limit); + buffer->_position += count; +} + +/** + * returns the maximum size of the buffer + * \param[in] buffer + * \return the size + */ +INLINE size_t +sldns_buffer_limit(sldns_buffer *buffer) +{ + return buffer->_limit; +} + +/** + * changes the buffer's limit. If the buffer's position is greater + * than the new limit the position is set to the limit. + * \param[in] buffer the buffer + * \param[in] limit the new limit + */ +INLINE void +sldns_buffer_set_limit(sldns_buffer *buffer, size_t limit) +{ + assert(limit <= buffer->_capacity); + buffer->_limit = limit; + if (buffer->_position > buffer->_limit) + buffer->_position = buffer->_limit; +} + +/** + * returns the number of bytes the buffer can hold. + * \param[in] buffer the buffer + * \return the number of bytes + */ +INLINE size_t +sldns_buffer_capacity(sldns_buffer *buffer) +{ + return buffer->_capacity; +} + +/** + * changes the buffer's capacity. The data is reallocated so any + * pointers to the data may become invalid. The buffer's limit is set + * to the buffer's new capacity. + * \param[in] buffer the buffer + * \param[in] capacity the capacity to use + * \return whether this failed or succeeded + */ +int sldns_buffer_set_capacity(sldns_buffer *buffer, size_t capacity); + +/** + * ensures BUFFER can contain at least AMOUNT more bytes. The buffer's + * capacity is increased if necessary using buffer_set_capacity(). + * + * The buffer's limit is always set to the (possibly increased) + * capacity. + * \param[in] buffer the buffer + * \param[in] amount amount to use + * \return whether this failed or succeeded + */ +int sldns_buffer_reserve(sldns_buffer *buffer, size_t amount); + +/** + * returns a pointer to the data at the indicated position. + * \param[in] buffer the buffer + * \param[in] at position + * \return the pointer to the data + */ +INLINE uint8_t * +sldns_buffer_at(const sldns_buffer *buffer, size_t at) +{ + assert(at <= buffer->_limit); + return buffer->_data + at; +} + +/** + * returns a pointer to the beginning of the buffer (the data at + * position 0). + * \param[in] buffer the buffer + * \return the pointer + */ +INLINE uint8_t * +sldns_buffer_begin(const sldns_buffer *buffer) +{ + return sldns_buffer_at(buffer, 0); +} + +/** + * returns a pointer to the end of the buffer (the data at the buffer's + * limit). + * \param[in] buffer the buffer + * \return the pointer + */ +INLINE uint8_t * +sldns_buffer_end(sldns_buffer *buffer) +{ + return sldns_buffer_at(buffer, buffer->_limit); +} + +/** + * returns a pointer to the data at the buffer's current position. + * \param[in] buffer the buffer + * \return the pointer + */ +INLINE uint8_t * +sldns_buffer_current(sldns_buffer *buffer) +{ + return sldns_buffer_at(buffer, buffer->_position); +} + +/** + * returns the number of bytes remaining between the indicated position and + * the limit. + * \param[in] buffer the buffer + * \param[in] at indicated position + * \return number of bytes + */ +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; +} + +/** + * returns the number of bytes remaining between the buffer's position and + * limit. + * \param[in] buffer the buffer + * \return the number of bytes + */ +INLINE size_t +sldns_buffer_remaining(sldns_buffer *buffer) +{ + return sldns_buffer_remaining_at(buffer, buffer->_position); +} + +/** + * checks if the buffer has at least COUNT more bytes available. + * Before reading or writing the caller needs to ensure enough space + * is available! + * \param[in] buffer the buffer + * \param[in] at indicated position + * \param[in] count how much is available + * \return true or false (as int?) + */ +INLINE int +sldns_buffer_available_at(sldns_buffer *buffer, size_t at, size_t count) +{ + return count <= sldns_buffer_remaining_at(buffer, at); +} + +/** + * checks if the buffer has count bytes available at the current position + * \param[in] buffer the buffer + * \param[in] count how much is available + * \return true or false (as int?) + */ +INLINE int +sldns_buffer_available(sldns_buffer *buffer, size_t count) +{ + return sldns_buffer_available_at(buffer, buffer->_position, count); +} + +/** + * writes the given data 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] data pointer to the data to write to the buffer + * \param[in] count the number of bytes of data to write + */ +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)); + memcpy(buffer->_data + at, data, 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 + * \param[in] count the lenght of the data to write + */ +INLINE void +sldns_buffer_write(sldns_buffer *buffer, const void *data, size_t count) +{ + sldns_buffer_write_at(buffer, buffer->_position, data, count); + buffer->_position += count; +} + +/** + * copies the given (null-delimited) string to the specified position at the buffer + * \param[in] buffer the buffer + * \param[in] at the position in the buffer + * \param[in] str the string to write + */ +INLINE void +sldns_buffer_write_string_at(sldns_buffer *buffer, size_t at, const char *str) +{ + sldns_buffer_write_at(buffer, at, str, strlen(str)); +} + +/** + * copies the given (null-delimited) string to the current position at the buffer + * \param[in] buffer the buffer + * \param[in] str the string to write + */ +INLINE void +sldns_buffer_write_string(sldns_buffer *buffer, const char *str) +{ + sldns_buffer_write(buffer, str, strlen(str)); +} + +/** + * writes the given byte of data at the given position in the buffer + * \param[in] buffer the buffer + * \param[in] at the position in the buffer + * \param[in] data the 8 bits to write + */ +INLINE void +sldns_buffer_write_u8_at(sldns_buffer *buffer, size_t at, uint8_t data) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(data))); + buffer->_data[at] = data; +} + +/** + * writes the given byte of data at the current position in the buffer + * \param[in] buffer the buffer + * \param[in] data the 8 bits to write + */ +INLINE void +sldns_buffer_write_u8(sldns_buffer *buffer, uint8_t data) +{ + sldns_buffer_write_u8_at(buffer, buffer->_position, data); + buffer->_position += sizeof(data); +} + +/** + * writes the given 2 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 16 bits to write + */ +INLINE void +sldns_buffer_write_u16_at(sldns_buffer *buffer, size_t at, uint16_t data) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(data))); + sldns_write_uint16(buffer->_data + at, data); +} + +/** + * writes the given 2 byte integer at the current position in the buffer + * \param[in] buffer the buffer + * \param[in] data the 16 bits to write + */ +INLINE void +sldns_buffer_write_u16(sldns_buffer *buffer, uint16_t data) +{ + sldns_buffer_write_u16_at(buffer, buffer->_position, data); + buffer->_position += sizeof(data); +} + +/** + * writes the given 4 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 32 bits to write + */ +INLINE void +sldns_buffer_write_u32_at(sldns_buffer *buffer, size_t at, uint32_t data) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(data))); + sldns_write_uint32(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 + */ +INLINE void +sldns_buffer_write_u32(sldns_buffer *buffer, uint32_t data) +{ + sldns_buffer_write_u32_at(buffer, buffer->_position, data); + buffer->_position += sizeof(data); +} + +/** + * 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 + * \param[out] data buffer to copy to + * \param[in] count the length of the data to copy + */ +INLINE void +sldns_buffer_read_at(sldns_buffer *buffer, size_t at, void *data, size_t count) +{ + assert(sldns_buffer_available_at(buffer, at, count)); + memcpy(data, buffer->_data + at, count); +} + +/** + * copies count bytes of data at the current position to the given data-array + * \param[in] buffer the buffer + * \param[out] data buffer to copy to + * \param[in] count the length of the data to copy + */ +INLINE void +sldns_buffer_read(sldns_buffer *buffer, void *data, size_t count) +{ + sldns_buffer_read_at(buffer, buffer->_position, data, count); + buffer->_position += count; +} + +/** + * returns the byte value at the given position in the buffer + * \param[in] buffer the buffer + * \param[in] at the position in the buffer + * \return 1 byte integer + */ +INLINE uint8_t +sldns_buffer_read_u8_at(sldns_buffer *buffer, size_t at) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(uint8_t))); + return buffer->_data[at]; +} + +/** + * returns the byte value at the current position in the buffer + * \param[in] buffer the buffer + * \return 1 byte integer + */ +INLINE uint8_t +sldns_buffer_read_u8(sldns_buffer *buffer) +{ + uint8_t result = sldns_buffer_read_u8_at(buffer, buffer->_position); + buffer->_position += sizeof(uint8_t); + return result; +} + +/** + * returns the 2-byte integer value at the given position in the buffer + * \param[in] buffer the buffer + * \param[in] at position in the buffer + * \return 2 byte integer + */ +INLINE uint16_t +sldns_buffer_read_u16_at(sldns_buffer *buffer, size_t at) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(uint16_t))); + return sldns_read_uint16(buffer->_data + at); +} + +/** + * returns the 2-byte integer value at the current position in the buffer + * \param[in] buffer the buffer + * \return 2 byte integer + */ +INLINE uint16_t +sldns_buffer_read_u16(sldns_buffer *buffer) +{ + uint16_t result = sldns_buffer_read_u16_at(buffer, buffer->_position); + buffer->_position += sizeof(uint16_t); + return result; +} + +/** + * returns the 4-byte integer value at the given position in the buffer + * \param[in] buffer the buffer + * \param[in] at position in the buffer + * \return 4 byte integer + */ +INLINE uint32_t +sldns_buffer_read_u32_at(sldns_buffer *buffer, size_t at) +{ + assert(sldns_buffer_available_at(buffer, at, sizeof(uint32_t))); + return sldns_read_uint32(buffer->_data + at); +} + +/** + * returns the 4-byte integer value at the current position in the buffer + * \param[in] buffer the buffer + * \return 4 byte integer + */ +INLINE uint32_t +sldns_buffer_read_u32(sldns_buffer *buffer) +{ + uint32_t result = sldns_buffer_read_u32_at(buffer, buffer->_position); + buffer->_position += sizeof(uint32_t); + return result; +} + +/** + * returns the status of the buffer + * \param[in] buffer + * \return the status + */ +INLINE int +sldns_buffer_status(sldns_buffer *buffer) +{ + return (int)buffer->_status_err; +} + +/** + * returns true if the status of the buffer is LDNS_STATUS_OK, false otherwise + * \param[in] buffer the buffer + * \return true or false + */ +INLINE int +sldns_buffer_status_ok(sldns_buffer *buffer) +{ + if (buffer) { + return sldns_buffer_status(buffer) == 0; + } else { + return 0; + } +} + +/** + * prints to the buffer, increasing the capacity if required using + * buffer_reserve(). The buffer's position is set to the terminating '\\0' + * Returns the number of characters written (not including the + * terminating '\\0') or -1 on failure. + */ +int sldns_buffer_printf(sldns_buffer *buffer, const char *format, ...) + ATTR_FORMAT(printf, 2, 3); + +/** + * frees the buffer. + * \param[in] *buffer the buffer to be freed + * \return void + */ +void sldns_buffer_free(sldns_buffer *buffer); + +/** + * Makes the buffer fixed and returns a pointer to the data. The + * caller is responsible for free'ing the result. + * \param[in] *buffer the buffer to be exported + * \return void + */ +void *sldns_buffer_export(sldns_buffer *buffer); + +/** + * Copy contents of the from buffer to the result buffer and then flips + * the result buffer. Data will be silently truncated if the result buffer is + * too small. + * \param[out] *result resulting buffer which is copied to. + * \param[in] *from what to copy to result. + */ +void sldns_buffer_copy(sldns_buffer* result, sldns_buffer* from); + +#ifdef __cplusplus +} +#endif + +#endif /* LDNS_SBUFFER_H */ |