Merge branch 'rightlib' into mergelibs-241019-1758

1 files changed, 712 insertions, 0 deletions

diff --git a/contrib/libs/c-ares/src/lib/include/ares_buf.h b/contrib/libs/c-ares/src/lib/include/ares_buf.h
new file mode 100644
index 0000000000..7836a313e0
--- /dev/null
+++ b/contrib/libs/c-ares/src/lib/include/ares_buf.h
@@ -0,0 +1,712 @@
+/* MIT License
+ *
+ * Copyright (c) 2023 Brad House
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * SPDX-License-Identifier: MIT
+ */
+#ifndef __ARES__BUF_H
+#define __ARES__BUF_H
+
+#include "ares.h"
+#include "ares_array.h"
+
+/*! \addtogroup ares_buf Safe Data Builder and buffer
+ *
+ * This is a buffer building and parsing framework with a focus on security over
+ * performance. All data to be read from the buffer will perform explicit length
+ * validation and return a success/fail result.  There are also various helpers
+ * for writing data to the buffer which dynamically grows.
+ *
+ * All operations that fetch or consume data from the buffer will move forward
+ * the internal pointer, thus marking the data as processed which may no longer
+ * be accessible after certain operations (such as append).
+ *
+ * The helpers for this object are meant to be added as needed.  If you can't
+ * find it, write it!
+ *
+ * @{
+ */
+struct ares_buf;
+
+/*! Opaque data type for generic hash table implementation */
+typedef struct ares_buf     ares_buf_t;
+
+/*! Create a new buffer object that dynamically allocates buffers for data.
+ *
+ *  \return initialized buffer object or NULL if out of memory.
+ */
+CARES_EXTERN ares_buf_t    *ares_buf_create(void);
+
+/*! Create a new buffer object that uses a user-provided data pointer.  The
+ *  data provided will not be manipulated, and cannot be appended to.  This
+ *  is strictly used for parsing.
+ *
+ *  \param[in] data     Data to provide to buffer, must not be NULL.
+ *  \param[in] data_len Size of buffer provided, must be > 0
+ *
+ *  \return initialized buffer object or NULL if out of memory or misuse.
+ */
+CARES_EXTERN ares_buf_t    *ares_buf_create_const(const unsigned char *data,
+                                                  size_t               data_len);
+
+
+/*! Destroy an initialized buffer object.
+ *
+ *  \param[in] buf  Initialized buf object
+ */
+CARES_EXTERN void           ares_buf_destroy(ares_buf_t *buf);
+
+
+/*! Append multiple bytes to a dynamic buffer object
+ *
+ *  \param[in] buf      Initialized buffer object
+ *  \param[in] data     Data to copy to buffer object
+ *  \param[in] data_len Length of data to copy to buffer object.
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_append(ares_buf_t          *buf,
+                                            const unsigned char *data,
+                                            size_t               data_len);
+
+/*! Append a single byte to the dynamic buffer object
+ *
+ *  \param[in] buf      Initialized buffer object
+ *  \param[in] b        Single byte to append to buffer object.
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_byte(ares_buf_t   *buf,
+                                                 unsigned char b);
+
+/*! Append a null-terminated string to the dynamic buffer object
+ *
+ *  \param[in] buf      Initialized buffer object
+ *  \param[in] str      String to append to buffer object.
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_str(ares_buf_t *buf,
+                                                const char *str);
+
+/*! Append a 16bit Big Endian number to the buffer.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] u16     16bit integer
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_be16(ares_buf_t    *buf,
+                                                 unsigned short u16);
+
+/*! Append a 32bit Big Endian number to the buffer.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] u32     32bit integer
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_be32(ares_buf_t  *buf,
+                                                 unsigned int u32);
+
+/*! Append a number in ASCII decimal form.
+ *
+ *  \param[in] buf  Initialized buffer object
+ *  \param[in] num  Number to print
+ *  \param[in] len  Length to output, use 0 for no padding
+ *  \return ARES_SUCCESS on success
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_num_dec(ares_buf_t *buf, size_t num,
+                                                    size_t len);
+
+/*! Append a number in ASCII hexadecimal form.
+ *
+ *  \param[in] buf  Initialized buffer object
+ *  \param[in] num  Number to print
+ *  \param[in] len  Length to output, use 0 for no padding
+ *  \return ARES_SUCCESS on success
+ */
+CARES_EXTERN ares_status_t  ares_buf_append_num_hex(ares_buf_t *buf, size_t num,
+                                                    size_t len);
+
+/*! Sets the current buffer length.  This *may* be used if there is a need to
+ *  override a prior position in the buffer, such as if there is a length
+ *  prefix that isn't easily predictable, and you must go back and overwrite
+ *  that position.
+ *
+ *  Only valid on non-const buffers.  Length provided must not exceed current
+ *  allocated buffer size, but otherwise there are very few protections on
+ *  this function.  Use cautiously.
+ *
+ *  \param[in]  buf  Initialized buffer object
+ *  \param[in]  len  Length to set
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_set_length(ares_buf_t *buf, size_t len);
+
+
+/*! Start a dynamic append operation that returns a buffer suitable for
+ *  writing.  A desired minimum length is passed in, and the actual allocated
+ *  buffer size is returned which may be greater than the requested size.
+ *  No operation other than ares_buf_append_finish() is allowed on the
+ *  buffer after this request.
+ *
+ *  \param[in]     buf     Initialized buffer object
+ *  \param[in,out] len     Desired non-zero length passed in, actual buffer size
+ *                         returned.
+ *  \return Pointer to writable buffer or NULL on failure (usage, out of mem)
+ */
+CARES_EXTERN unsigned char *ares_buf_append_start(ares_buf_t *buf, size_t *len);
+
+/*! Finish a dynamic append operation.  Called after
+ *  ares_buf_append_start() once desired data is written.
+ *
+ *  \param[in] buf    Initialized buffer object.
+ *  \param[in] len    Length of data written.  May be zero to terminate
+ *                    operation. Must not be greater than returned from
+ *                    ares_buf_append_start().
+ */
+CARES_EXTERN void           ares_buf_append_finish(ares_buf_t *buf, size_t len);
+
+/*! Write the data provided to the buffer in a hexdump format.
+ *
+ *  \param[in] buf      Initialized buffer object.
+ *  \param[in] data     Data to hex dump
+ *  \param[in] len      Length of data to hexdump
+ *  \return ARES_SUCCESS on success.
+ */
+CARES_EXTERN ares_status_t  ares_buf_hexdump(ares_buf_t          *buf,
+                                             const unsigned char *data,
+                                             size_t               len);
+
+/*! Clean up ares_buf_t and return allocated pointer to unprocessed data.  It
+ *  is the responsibility of the  caller to ares_free() the returned buffer.
+ *  The passed in buf parameter is invalidated by this call.
+ *
+ * \param[in]  buf    Initialized buffer object. Can not be a "const" buffer.
+ * \param[out] len    Length of data returned
+ * \return pointer to unprocessed data (may be zero length) or NULL on error.
+ */
+CARES_EXTERN unsigned char *ares_buf_finish_bin(ares_buf_t *buf, size_t *len);
+
+/*! Clean up ares_buf_t and return allocated pointer to unprocessed data and
+ *  return it as a string (null terminated).  It is the responsibility of the
+ *  caller to ares_free() the returned buffer. The passed in buf parameter is
+ *  invalidated by this call.
+ *
+ *  This function in no way validates the data in this buffer is actually
+ *  a string, that characters are printable, or that there aren't multiple
+ *  NULL terminators.  It is assumed that the caller will either validate that
+ *  themselves or has built this buffer with only a valid character set.
+ *
+ * \param[in]  buf    Initialized buffer object. Can not be a "const" buffer.
+ * \param[out] len    Optional. Length of data returned, or NULL if not needed.
+ * \return pointer to unprocessed data or NULL on error.
+ */
+CARES_EXTERN char          *ares_buf_finish_str(ares_buf_t *buf, size_t *len);
+
+/*! Tag a position to save in the buffer in case parsing needs to rollback,
+ *  such as if insufficient data is available, but more data may be added in
+ *  the future.  Only a single tag can be set per buffer object.  Setting a
+ *  tag will override any pre-existing tag.
+ *
+ *  \param[in] buf Initialized buffer object
+ */
+CARES_EXTERN void           ares_buf_tag(ares_buf_t *buf);
+
+/*! Rollback to a tagged position.  Will automatically clear the tag.
+ *
+ *  \param[in] buf Initialized buffer object
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_tag_rollback(ares_buf_t *buf);
+
+/*! Clear the tagged position without rolling back.  You should do this any
+ *  time a tag is no longer needed as future append operations can reclaim
+ *  buffer space.
+ *
+ *  \param[in] buf Initialized buffer object
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t  ares_buf_tag_clear(ares_buf_t *buf);
+
+/*! Fetch the buffer and length of data starting from the tagged position up
+ *  to the _current_ position.  It will not unset the tagged position.  The
+ *  data may be invalidated by any future ares_buf_*() calls.
+ *
+ *  \param[in]  buf    Initialized buffer object
+ *  \param[out] len    Length between tag and current offset in buffer
+ *  \return NULL on failure (such as no tag), otherwise pointer to start of
+ *          buffer
+ */
+CARES_EXTERN const unsigned char *ares_buf_tag_fetch(const ares_buf_t *buf,
+                                                     size_t           *len);
+
+/*! Get the length of the current tag offset to the current position.
+ *
+ *  \param[in]  buf    Initialized buffer object
+ *  \return length
+ */
+CARES_EXTERN size_t               ares_buf_tag_length(const ares_buf_t *buf);
+
+/*! Fetch the bytes starting from the tagged position up to the _current_
+ *  position using the provided buffer.  It will not unset the tagged position.
+ *
+ *  \param[in]     buf    Initialized buffer object
+ *  \param[in,out] bytes  Buffer to hold data
+ *  \param[in,out] len    On input, buffer size, on output, bytes place in
+ *                        buffer.
+ *  \return ARES_SUCCESS if fetched, ARES_EFORMERR if insufficient buffer size
+ */
+CARES_EXTERN ares_status_t ares_buf_tag_fetch_bytes(const ares_buf_t *buf,
+                                                    unsigned char    *bytes,
+                                                    size_t           *len);
+
+/*! Fetch the bytes starting from the tagged position up to the _current_
+ *  position as a NULL-terminated string using the provided buffer.  The data
+ *  is validated to be ASCII-printable data.  It will not unset the tagged
+ *  position.
+ *
+ *  \param[in]     buf    Initialized buffer object
+ *  \param[in,out] str    Buffer to hold data
+ *  \param[in]     len    buffer size
+ *  \return ARES_SUCCESS if fetched, ARES_EFORMERR if insufficient buffer size,
+ *          ARES_EBADSTR if not printable ASCII
+ */
+CARES_EXTERN ares_status_t ares_buf_tag_fetch_string(const ares_buf_t *buf,
+                                                     char *str, size_t len);
+
+/*! Fetch the bytes starting from the tagged position up to the _current_
+ *  position as a NULL-terminated string and placed into a newly allocated
+ *  buffer.  The data is validated to be ASCII-printable data.  It will not
+ *  unset the tagged position.
+ *
+ *  \param[in]  buf    Initialized buffer object
+ *  \param[out] str    New buffer to hold output, free with ares_free()
+ *
+ *  \return ARES_SUCCESS if fetched, ARES_EFORMERR if insufficient buffer size,
+ *          ARES_EBADSTR if not printable ASCII
+ */
+CARES_EXTERN ares_status_t ares_buf_tag_fetch_strdup(const ares_buf_t *buf,
+                                                     char            **str);
+
+/*! Fetch the bytes starting from the tagged position up to the _current_
+ *  position as const buffer.  Care must be taken to not append or destroy the
+ *  passed in buffer until the newly fetched buffer is no longer needed since
+ *  it points to memory inside the passed in buffer which could be invalidated.
+ *
+ *  \param[in]     buf    Initialized buffer object
+ *  \param[out]    newbuf New const buffer object, must be destroyed when done.
+
+ *  \return ARES_SUCCESS if fetched
+ */
+CARES_EXTERN ares_status_t ares_buf_tag_fetch_constbuf(const ares_buf_t *buf,
+                                                       ares_buf_t **newbuf);
+
+/*! Consume the given number of bytes without reading them.
+ *
+ *  \param[in] buf    Initialized buffer object
+ *  \param[in] len    Length to consume
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_consume(ares_buf_t *buf, size_t len);
+
+/*! Fetch a 16bit Big Endian number from the buffer.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] u16     Buffer to hold 16bit integer
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_be16(ares_buf_t     *buf,
+                                               unsigned short *u16);
+
+/*! Fetch a 32bit Big Endian number from the buffer.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] u32     Buffer to hold 32bit integer
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_be32(ares_buf_t   *buf,
+                                               unsigned int *u32);
+
+
+/*! Fetch the requested number of bytes into the provided buffer
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] bytes   Buffer to hold data
+ *  \param[in]  len     Requested number of bytes (must be > 0)
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_bytes(ares_buf_t    *buf,
+                                                unsigned char *bytes,
+                                                size_t         len);
+
+
+/*! Fetch the requested number of bytes and return a new buffer that must be
+ *  ares_free()'d by the caller.
+ *
+ *  \param[in]  buf       Initialized buffer object
+ *  \param[in]  len       Requested number of bytes (must be > 0)
+ *  \param[in]  null_term Even though this is considered binary data, the user
+ *                        knows it may be a vald string, so add a null
+ *                        terminator.
+ *  \param[out] bytes     Pointer passed by reference. Will be allocated.
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_bytes_dup(ares_buf_t *buf, size_t len,
+                                                    ares_bool_t     null_term,
+                                                    unsigned char **bytes);
+
+/*! Fetch the requested number of bytes and place them into the provided
+ *  dest buffer object.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[out] dest    Buffer object to append bytes.
+ *  \param[in]  len     Requested number of bytes (must be > 0)
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_bytes_into_buf(ares_buf_t *buf,
+                                                         ares_buf_t *dest,
+                                                         size_t      len);
+
+/*! Fetch the requested number of bytes and return a new buffer that must be
+ *  ares_free()'d by the caller.  The returned buffer is a null terminated
+ *  string.  The data is validated to be ASCII-printable.
+ *
+ *  \param[in]  buf     Initialized buffer object
+ *  \param[in]  len     Requested number of bytes (must be > 0)
+ *  \param[out] str     Pointer passed by reference. Will be allocated.
+ *  \return ARES_SUCCESS or one of the c-ares error codes
+ */
+CARES_EXTERN ares_status_t ares_buf_fetch_str_dup(ares_buf_t *buf, size_t len,
+                                                  char **str);
+
+/*! Consume whitespace characters (0x09, 0x0B, 0x0C, 0x0D, 0x20, and optionally
+ *  0x0A).
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \param[in]  include_linefeed  ARES_TRUE to include consuming 0x0A,
+ *                                ARES_FALSE otherwise.
+ *  \return number of whitespace characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_whitespace(ares_buf_t *buf,
+                                                       ares_bool_t include_linefeed);
+
+
+/*! Consume any non-whitespace character (anything other than 0x09, 0x0B, 0x0C,
+ *  0x0D, 0x20, and 0x0A).
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \return number of characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_nonwhitespace(ares_buf_t *buf);
+
+
+/*! Consume until a character in the character set provided is reached.  Does
+ *  not include the character from the charset at the end.
+ *
+ *  \param[in] buf                Initialized buffer object
+ *  \param[in] charset            character set
+ *  \param[in] len                length of character set
+ *  \param[in] require_charset    require we find a character from the charset.
+ *                                if ARES_FALSE it will simply consume the
+ *                                rest of the buffer.  If ARES_TRUE will return
+ *                                SIZE_MAX if not found.
+ *  \return number of characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_until_charset(ares_buf_t          *buf,
+                                                          const unsigned char *charset,
+                                                          size_t               len,
+                                                          ares_bool_t require_charset);
+
+
+/*! Consume until a sequence of bytes is encountered.  Does not include the
+ *  sequence of characters itself.
+ *
+ *  \param[in] buf                Initialized buffer object
+ *  \param[in] seq                sequence of bytes
+ *  \param[in] len                length of sequence
+ *  \param[in] require_charset    require we find the sequence.
+ *                                if ARES_FALSE it will simply consume the
+ *                                rest of the buffer.  If ARES_TRUE will return
+ *                                SIZE_MAX if not found.
+ *  \return number of characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_until_seq(ares_buf_t          *buf,
+                                                      const unsigned char *seq,
+                                                      size_t               len,
+                                                      ares_bool_t require_seq);
+
+/*! Consume while the characters match the characters in the provided set.
+ *
+ *  \param[in] buf                Initialized buffer object
+ *  \param[in] charset            character set
+ *  \param[in] len                length of character set
+ *  \return number of characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_charset(ares_buf_t          *buf,
+                                                    const unsigned char *charset,
+                                                    size_t               len);
+
+
+/*! Consume from the current position until the end of the line, and optionally
+ *  the end of line character (0x0A) itself.
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \param[in]  include_linefeed  ARES_TRUE to include consuming 0x0A,
+ *                                ARES_FALSE otherwise.
+ *  \return number of characters consumed
+ */
+CARES_EXTERN size_t        ares_buf_consume_line(ares_buf_t *buf,
+                                                 ares_bool_t include_linefeed);
+
+typedef enum {
+  /*! No flags */
+  ARES_BUF_SPLIT_NONE = 0,
+  /*! The delimiter will be the first character in the buffer, except the
+   *  first buffer since the start doesn't have a delimiter.  This option is
+   *  incompatible with ARES_BUF_SPLIT_LTRIM since the delimiter is always
+   *  the first character.
+   */
+  ARES_BUF_SPLIT_KEEP_DELIMS = 1 << 0,
+  /*! Allow blank sections, by default blank sections are not emitted.  If using
+   *  ARES_BUF_SPLIT_KEEP_DELIMS, the delimiter is not counted as part
+   *  of the section */
+  ARES_BUF_SPLIT_ALLOW_BLANK = 1 << 1,
+  /*! Remove duplicate entries */
+  ARES_BUF_SPLIT_NO_DUPLICATES = 1 << 2,
+  /*! Perform case-insensitive matching when comparing values */
+  ARES_BUF_SPLIT_CASE_INSENSITIVE = 1 << 3,
+  /*! Trim leading whitespace from buffer */
+  ARES_BUF_SPLIT_LTRIM = 1 << 4,
+  /*! Trim trailing whitespace from buffer */
+  ARES_BUF_SPLIT_RTRIM = 1 << 5,
+  /*! Trim leading and trailing whitespace from buffer */
+  ARES_BUF_SPLIT_TRIM = (ARES_BUF_SPLIT_LTRIM | ARES_BUF_SPLIT_RTRIM)
+} ares_buf_split_t;
+
+/*! Split the provided buffer into multiple sub-buffers stored in the variable
+ *  pointed to by the linked list.  The sub buffers are const buffers pointing
+ *  into the buf provided.
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \param[in]  delims            Possible delimiters
+ *  \param[in]  delims_len        Length of possible delimiters
+ *  \param[in]  flags             One more more flags
+ *  \param[in]  max_sections      Maximum number of sections.  Use 0 for
+ *                                unlimited. Useful for splitting key/value
+ *                                pairs where the delimiter may be a valid
+ *                                character in the value.  A value of 1 would
+ *                                have little usefulness and would effectively
+ *                                ignore the delimiter itself.
+ *  \param[out] arr               Result. Depending on flags, this may be a
+ *                                valid array with no elements.  Use
+ *                                ares_array_destroy() to free the memory which
+ *                                will also free the contained ares_buf_t *
+ *                                objects. Each buf object returned by
+ *                                ares_array_at() or similar is a pointer to
+ *                                an ares_buf_t * object, meaning you need to
+ *                                accept it as "ares_buf_t **" then dereference.
+ *  \return ARES_SUCCESS on success, or error like ARES_ENOMEM.
+ */
+CARES_EXTERN ares_status_t ares_buf_split(
+  ares_buf_t *buf, const unsigned char *delims, size_t delims_len,
+  ares_buf_split_t flags, size_t max_sections, ares_array_t **arr);
+
+/*! Split the provided buffer into an ares_array_t of C strings.
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \param[in]  delims            Possible delimiters
+ *  \param[in]  delims_len        Length of possible delimiters
+ *  \param[in]  flags             One more more flags
+ *  \param[in]  max_sections      Maximum number of sections.  Use 0 for
+ *                                unlimited. Useful for splitting key/value
+ *                                pairs where the delimiter may be a valid
+ *                                character in the value.  A value of 1 would
+ *                                have little usefulness and would effectively
+ *                                ignore the delimiter itself.
+ *  \param[out] arr               Array of strings. Free using
+ *                                ares_array_destroy().
+ *  \return ARES_SUCCESS on success, or error like ARES_ENOMEM.
+ */
+CARES_EXTERN ares_status_t ares_buf_split_str_array(
+  ares_buf_t *buf, const unsigned char *delims, size_t delims_len,
+  ares_buf_split_t flags, size_t max_sections, ares_array_t **arr);
+
+/*! Split the provided buffer into a C array of C strings.
+ *
+ *  \param[in]  buf               Initialized buffer object
+ *  \param[in]  delims            Possible delimiters
+ *  \param[in]  delims_len        Length of possible delimiters
+ *  \param[in]  flags             One more more flags
+ *  \param[in]  max_sections      Maximum number of sections.  Use 0 for
+ *                                unlimited. Useful for splitting key/value
+ *                                pairs where the delimiter may be a valid
+ *                                character in the value.  A value of 1 would
+ *                                have little usefulness and would effectively
+ *                                ignore the delimiter itself.
+ *  \param[out] strs              Array of strings. Free using
+ *                                ares_free_array(strs, nstrs, ares_free)
+ *  \param[out] nstrs             Number of elements in the array.
+ *  \return ARES_SUCCESS on success, or error like ARES_ENOMEM.
+ */
+CARES_EXTERN ares_status_t ares_buf_split_str(
+  ares_buf_t *buf, const unsigned char *delims, size_t delims_len,
+  ares_buf_split_t flags, size_t max_sections, char ***strs, size_t *nstrs);
+
+/*! Check the unprocessed buffer to see if it begins with the sequence of
+ *  characters provided.
+ *
+ *  \param[in] buf          Initialized buffer object
+ *  \param[in] data         Bytes of data to compare.
+ *  \param[in] data_len     Length of data to compare.
+ *  \return ARES_TRUE on match, ARES_FALSE otherwise.
+ */
+CARES_EXTERN ares_bool_t          ares_buf_begins_with(const ares_buf_t    *buf,
+                                                       const unsigned char *data,
+                                                       size_t               data_len);
+
+
+/*! Size of unprocessed remaining data length
+ *
+ *  \param[in] buf Initialized buffer object
+ *  \return length remaining
+ */
+CARES_EXTERN size_t               ares_buf_len(const ares_buf_t *buf);
+
+/*! Retrieve a pointer to the currently unprocessed data.  Generally this isn't
+ *  recommended to be used in practice.  The returned pointer may be invalidated
+ *  by any future ares_buf_*() calls.
+ *
+ *  \param[in]  buf    Initialized buffer object
+ *  \param[out] len    Length of available data
+ *  \return Pointer to buffer of unprocessed data
+ */
+CARES_EXTERN const unsigned char *ares_buf_peek(const ares_buf_t *buf,
+                                                size_t           *len);
+
+/*! Retrieve the next byte in the buffer without moving forward.
+ *
+ *  \param[in]  buf  Initialized buffer object
+ *  \param[out] b    Single byte
+ *  \return \return ARES_SUCCESS on success, or error
+ */
+CARES_EXTERN ares_status_t        ares_buf_peek_byte(const ares_buf_t *buf,
+                                                     unsigned char    *b);
+
+/*! Wipe any processed data from the beginning of the buffer.  This will
+ *  move any remaining data to the front of the internally allocated buffer.
+ *
+ *  Can not be used on const buffer objects.
+ *
+ *  Typically not needed to call, as any new append operation will automatically
+ *  call this function if there is insufficient space to append the data in
+ *  order to try to avoid another memory allocation.
+ *
+ *  It may be useful to call in order to ensure the current message being
+ *  processed is in the beginning of the buffer if there is an intent to use
+ *  ares_buf_set_position() and ares_buf_get_position() as may be necessary
+ *  when processing DNS compressed names.
+ *
+ *  If there is an active tag, it will NOT clear the tag, it will use the tag
+ *  as the start of the unprocessed data rather than the current offset.  If
+ *  a prior tag is no longer needed, may be wise to call ares_buf_tag_clear().
+ *
+ *  \param[in]  buf    Initialized buffer object
+ */
+CARES_EXTERN void                 ares_buf_reclaim(ares_buf_t *buf);
+
+/*! Set the current offset within the internal buffer.
+ *
+ *  Typically this should not be used, if possible, use the ares_buf_tag*()
+ *  operations instead.
+ *
+ *  One exception is DNS name compression which may backwards reference to
+ *  an index in the message.  It may be necessary in such a case to call
+ *  ares_buf_reclaim() if using a dynamic (non-const) buffer before processing
+ *  such a message.
+ *
+ *  \param[in] buf  Initialized buffer object
+ *  \param[in] idx  Index to set position
+ *  \return ARES_SUCCESS if valid index
+ */
+CARES_EXTERN ares_status_t ares_buf_set_position(ares_buf_t *buf, size_t idx);
+
+/*! Get the current offset within the internal buffer.
+ *
+ *  Typically this should not be used, if possible, use the ares_buf_tag*()
+ *  operations instead.
+ *
+ *  This can be used to get the current position, useful for saving if a
+ *  jump via ares_buf_set_position() is performed and need to restore the
+ *  current position for future operations.
+ *
+ *  \param[in] buf Initialized buffer object
+ *  \return index of current position
+ */
+CARES_EXTERN size_t        ares_buf_get_position(const ares_buf_t *buf);
+
+/*! Parse a character-string as defined in RFC1035, as a null-terminated
+ *  string.
+ *
+ *  \param[in]  buf            initialized buffer object
+ *  \param[in]  remaining_len  maximum length that should be used for parsing
+ *                             the string, this is often less than the remaining
+ *                             buffer and is based on the RR record length.
+ *  \param[out] name           Pointer passed by reference to be filled in with
+ *                             allocated string of the parsed that must be
+ *                             ares_free()'d by the caller.
+ *  \return ARES_SUCCESS on success
+ */
+CARES_EXTERN ares_status_t ares_buf_parse_dns_str(ares_buf_t *buf,
+                                                  size_t      remaining_len,
+                                                  char      **name);
+
+/*! Parse a character-string as defined in RFC1035, as binary, however for
+ *  convenience this does guarantee a NULL terminator (that is not included
+ *  in the returned length).
+ *
+ *  \param[in]  buf            initialized buffer object
+ *  \param[in]  remaining_len  maximum length that should be used for parsing
+ *                             the string, this is often less than the remaining
+ *                             buffer and is based on the RR record length.
+ *  \param[out] bin            Pointer passed by reference to be filled in with
+ *                             allocated string of the parsed that must be
+ *                             ares_free()'d by the caller.
+ *  \param[out] bin_len        Length of returned string.
+ *  \return ARES_SUCCESS on success
+ */
+CARES_EXTERN ares_status_t ares_buf_parse_dns_binstr(ares_buf_t *buf,
+                                                     size_t      remaining_len,
+                                                     unsigned char **bin,
+                                                     size_t         *bin_len);
+
+/*! Load data from specified file path into provided buffer.  The entire file
+ *  is loaded into memory.
+ *
+ *  \param[in]     filename complete path to file
+ *  \param[in,out] buf      Initialized (non-const) buffer object to load data
+ *                          into
+ *  \return ARES_ENOTFOUND if file not found, ARES_EFILE if issues reading
+ *          file, ARES_ENOMEM if out of memory, ARES_SUCCESS on success.
+ */
+CARES_EXTERN ares_status_t ares_buf_load_file(const char *filename,
+                                              ares_buf_t *buf);
+
+/*! @} */
+
+#endif /* __ARES__BUF_H */