Update contrib/libs/c-ares to 1.34.2

commit_hash:abd65f143c484666e1545e6bbfb9d947df95ecd6

1 files changed, 1432 insertions, 0 deletions

diff --git a/contrib/libs/c-ares/src/lib/str/ares_buf.c b/contrib/libs/c-ares/src/lib/str/ares_buf.c
new file mode 100644
index 0000000000..69e6b38aac
--- /dev/null
+++ b/contrib/libs/c-ares/src/lib/str/ares_buf.c
@@ -0,0 +1,1432 @@
+/* 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
+ */
+#include "ares_private.h"
+#include "ares_buf.h"
+#include <limits.h>
+#ifdef HAVE_STDINT_H
+#  include <stdint.h>
+#endif
+
+struct ares_buf {
+  const unsigned char *data;          /*!< pointer to start of data buffer */
+  size_t               data_len;      /*!< total size of data in buffer */
+
+  unsigned char       *alloc_buf;     /*!< Pointer to allocated data buffer,
+                                       *   not used for const buffers */
+  size_t               alloc_buf_len; /*!< Size of allocated data buffer */
+
+  size_t               offset;        /*!< Current working offset in buffer */
+  size_t               tag_offset;    /*!< Tagged offset in buffer. Uses
+                                       *   SIZE_MAX if not set. */
+};
+
+ares_buf_t *ares_buf_create(void)
+{
+  ares_buf_t *buf = ares_malloc_zero(sizeof(*buf));
+  if (buf == NULL) {
+    return NULL;
+  }
+
+  buf->tag_offset = SIZE_MAX;
+  return buf;
+}
+
+ares_buf_t *ares_buf_create_const(const unsigned char *data, size_t data_len)
+{
+  ares_buf_t *buf;
+
+  if (data == NULL || data_len == 0) {
+    return NULL;
+  }
+
+  buf = ares_buf_create();
+  if (buf == NULL) {
+    return NULL;
+  }
+
+  buf->data     = data;
+  buf->data_len = data_len;
+
+  return buf;
+}
+
+void ares_buf_destroy(ares_buf_t *buf)
+{
+  if (buf == NULL) {
+    return;
+  }
+  ares_free(buf->alloc_buf);
+  ares_free(buf);
+}
+
+static ares_bool_t ares_buf_is_const(const ares_buf_t *buf)
+{
+  if (buf == NULL) {
+    return ARES_FALSE; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  if (buf->data != NULL && buf->alloc_buf == NULL) {
+    return ARES_TRUE;
+  }
+
+  return ARES_FALSE;
+}
+
+void ares_buf_reclaim(ares_buf_t *buf)
+{
+  size_t prefix_size;
+  size_t data_size;
+
+  if (buf == NULL) {
+    return;
+  }
+
+  if (ares_buf_is_const(buf)) {
+    return; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  /* Silence coverity.  All lengths are zero so would bail out later but
+   * coverity doesn't know this */
+  if (buf->alloc_buf == NULL) {
+    return;
+  }
+
+  if (buf->tag_offset != SIZE_MAX && buf->tag_offset < buf->offset) {
+    prefix_size = buf->tag_offset;
+  } else {
+    prefix_size = buf->offset;
+  }
+
+  if (prefix_size == 0) {
+    return;
+  }
+
+  data_size = buf->data_len - prefix_size;
+
+  memmove(buf->alloc_buf, buf->alloc_buf + prefix_size, data_size);
+  buf->data      = buf->alloc_buf;
+  buf->data_len  = data_size;
+  buf->offset   -= prefix_size;
+  if (buf->tag_offset != SIZE_MAX) {
+    buf->tag_offset -= prefix_size;
+  }
+}
+
+static ares_status_t ares_buf_ensure_space(ares_buf_t *buf, size_t needed_size)
+{
+  size_t         remaining_size;
+  size_t         alloc_size;
+  unsigned char *ptr;
+
+  if (buf == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (ares_buf_is_const(buf)) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  /* When calling ares_buf_finish_str() we end up adding a null terminator,
+   * so we want to ensure the size is always sufficient for this as we don't
+   * want an ARES_ENOMEM at that point */
+  needed_size++;
+
+  /* No need to do an expensive move operation, we have enough to just append */
+  remaining_size = buf->alloc_buf_len - buf->data_len;
+  if (remaining_size >= needed_size) {
+    return ARES_SUCCESS;
+  }
+
+  /* See if just moving consumed data frees up enough space */
+  ares_buf_reclaim(buf);
+
+  remaining_size = buf->alloc_buf_len - buf->data_len;
+  if (remaining_size >= needed_size) {
+    return ARES_SUCCESS;
+  }
+
+  alloc_size = buf->alloc_buf_len;
+
+  /* Not yet started */
+  if (alloc_size == 0) {
+    alloc_size = 16; /* Always shifts 1, so ends up being 32 minimum */
+  }
+
+  /* Increase allocation by powers of 2 */
+  do {
+    alloc_size     <<= 1;
+    remaining_size   = alloc_size - buf->data_len;
+  } while (remaining_size < needed_size);
+
+  ptr = ares_realloc(buf->alloc_buf, alloc_size);
+  if (ptr == NULL) {
+    return ARES_ENOMEM;
+  }
+
+  buf->alloc_buf     = ptr;
+  buf->alloc_buf_len = alloc_size;
+  buf->data          = ptr;
+
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_set_length(ares_buf_t *buf, size_t len)
+{
+  if (buf == NULL || ares_buf_is_const(buf)) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  if (len >= buf->alloc_buf_len - buf->offset) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  buf->data_len = len + buf->offset;
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_append(ares_buf_t *buf, const unsigned char *data,
+                              size_t data_len)
+{
+  ares_status_t status;
+
+  if (data == NULL && data_len != 0) {
+    return ARES_EFORMERR;
+  }
+
+  if (data_len == 0) {
+    return ARES_SUCCESS;
+  }
+
+  status = ares_buf_ensure_space(buf, data_len);
+  if (status != ARES_SUCCESS) {
+    return status;
+  }
+
+  memcpy(buf->alloc_buf + buf->data_len, data, data_len);
+  buf->data_len += data_len;
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_append_byte(ares_buf_t *buf, unsigned char b)
+{
+  return ares_buf_append(buf, &b, 1);
+}
+
+ares_status_t ares_buf_append_be16(ares_buf_t *buf, unsigned short u16)
+{
+  ares_status_t status;
+
+  status = ares_buf_append_byte(buf, (unsigned char)((u16 >> 8) & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  status = ares_buf_append_byte(buf, (unsigned char)(u16 & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_append_be32(ares_buf_t *buf, unsigned int u32)
+{
+  ares_status_t status;
+
+  status = ares_buf_append_byte(buf, ((unsigned char)(u32 >> 24) & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  status = ares_buf_append_byte(buf, ((unsigned char)(u32 >> 16) & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  status = ares_buf_append_byte(buf, ((unsigned char)(u32 >> 8) & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  status = ares_buf_append_byte(buf, ((unsigned char)u32 & 0xff));
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  return ARES_SUCCESS;
+}
+
+unsigned char *ares_buf_append_start(ares_buf_t *buf, size_t *len)
+{
+  ares_status_t status;
+
+  if (len == NULL || *len == 0) {
+    return NULL;
+  }
+
+  status = ares_buf_ensure_space(buf, *len);
+  if (status != ARES_SUCCESS) {
+    return NULL;
+  }
+
+  /* -1 for possible null terminator for ares_buf_finish_str() */
+  *len = buf->alloc_buf_len - buf->data_len - 1;
+  return buf->alloc_buf + buf->data_len;
+}
+
+void ares_buf_append_finish(ares_buf_t *buf, size_t len)
+{
+  if (buf == NULL) {
+    return;
+  }
+
+  buf->data_len += len;
+}
+
+unsigned char *ares_buf_finish_bin(ares_buf_t *buf, size_t *len)
+{
+  unsigned char *ptr = NULL;
+  if (buf == NULL || len == NULL || ares_buf_is_const(buf)) {
+    return NULL;
+  }
+
+  ares_buf_reclaim(buf);
+
+  /* We don't want to return NULL except on failure, may be zero-length */
+  if (buf->alloc_buf == NULL && ares_buf_ensure_space(buf, 1) != ARES_SUCCESS) {
+    return NULL; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+  ptr  = buf->alloc_buf;
+  *len = buf->data_len;
+  ares_free(buf);
+  return ptr;
+}
+
+char *ares_buf_finish_str(ares_buf_t *buf, size_t *len)
+{
+  char  *ptr;
+  size_t mylen;
+
+  ptr = (char *)ares_buf_finish_bin(buf, &mylen);
+  if (ptr == NULL) {
+    return NULL;
+  }
+
+  if (len != NULL) {
+    *len = mylen;
+  }
+
+  /* NOTE: ensured via ares_buf_ensure_space() that there is always at least
+   *       1 extra byte available for this specific use-case */
+  ptr[mylen] = 0;
+
+  return ptr;
+}
+
+void ares_buf_tag(ares_buf_t *buf)
+{
+  if (buf == NULL) {
+    return;
+  }
+
+  buf->tag_offset = buf->offset;
+}
+
+ares_status_t ares_buf_tag_rollback(ares_buf_t *buf)
+{
+  if (buf == NULL || buf->tag_offset == SIZE_MAX) {
+    return ARES_EFORMERR;
+  }
+
+  buf->offset     = buf->tag_offset;
+  buf->tag_offset = SIZE_MAX;
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_tag_clear(ares_buf_t *buf)
+{
+  if (buf == NULL || buf->tag_offset == SIZE_MAX) {
+    return ARES_EFORMERR;
+  }
+
+  buf->tag_offset = SIZE_MAX;
+  return ARES_SUCCESS;
+}
+
+const unsigned char *ares_buf_tag_fetch(const ares_buf_t *buf, size_t *len)
+{
+  if (buf == NULL || buf->tag_offset == SIZE_MAX || len == NULL) {
+    return NULL;
+  }
+
+  *len = buf->offset - buf->tag_offset;
+  return buf->data + buf->tag_offset;
+}
+
+size_t ares_buf_tag_length(const ares_buf_t *buf)
+{
+  if (buf == NULL || buf->tag_offset == SIZE_MAX) {
+    return 0;
+  }
+  return buf->offset - buf->tag_offset;
+}
+
+ares_status_t ares_buf_tag_fetch_bytes(const ares_buf_t *buf,
+                                       unsigned char *bytes, size_t *len)
+{
+  size_t               ptr_len = 0;
+  const unsigned char *ptr     = ares_buf_tag_fetch(buf, &ptr_len);
+
+  if (ptr == NULL || bytes == NULL || len == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (*len < ptr_len) {
+    return ARES_EFORMERR;
+  }
+
+  *len = ptr_len;
+
+  if (ptr_len > 0) {
+    memcpy(bytes, ptr, ptr_len);
+  }
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_tag_fetch_constbuf(const ares_buf_t *buf,
+                                          ares_buf_t      **newbuf)
+{
+  size_t               ptr_len = 0;
+  const unsigned char *ptr     = ares_buf_tag_fetch(buf, &ptr_len);
+
+  if (ptr == NULL || newbuf == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  *newbuf = ares_buf_create_const(ptr, ptr_len);
+  if (*newbuf == NULL) {
+    return ARES_ENOMEM;
+  }
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_tag_fetch_string(const ares_buf_t *buf, char *str,
+                                        size_t len)
+{
+  size_t        out_len;
+  ares_status_t status;
+  size_t        i;
+
+  if (str == NULL || len == 0) {
+    return ARES_EFORMERR;
+  }
+
+  /* Space for NULL terminator */
+  out_len = len - 1;
+
+  status = ares_buf_tag_fetch_bytes(buf, (unsigned char *)str, &out_len);
+  if (status != ARES_SUCCESS) {
+    return status;
+  }
+
+  /* NULL terminate */
+  str[out_len] = 0;
+
+  /* Validate string is printable */
+  for (i = 0; i < out_len; i++) {
+    if (!ares_isprint(str[i])) {
+      return ARES_EBADSTR;
+    }
+  }
+
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_tag_fetch_strdup(const ares_buf_t *buf, char **str)
+{
+  size_t               ptr_len = 0;
+  const unsigned char *ptr     = ares_buf_tag_fetch(buf, &ptr_len);
+
+  if (ptr == NULL || str == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (!ares_str_isprint((const char *)ptr, ptr_len)) {
+    return ARES_EBADSTR;
+  }
+
+  *str = ares_malloc(ptr_len + 1);
+  if (*str == NULL) {
+    return ARES_ENOMEM;
+  }
+
+  if (ptr_len > 0) {
+    memcpy(*str, ptr, ptr_len);
+  }
+  (*str)[ptr_len] = 0;
+  return ARES_SUCCESS;
+}
+
+static const unsigned char *ares_buf_fetch(const ares_buf_t *buf, size_t *len)
+{
+  if (len != NULL) {
+    *len = 0;
+  }
+
+  if (buf == NULL || len == NULL || buf->data == NULL) {
+    return NULL;
+  }
+
+  *len = buf->data_len - buf->offset;
+  if (*len == 0) {
+    return NULL;
+  }
+
+  return buf->data + buf->offset;
+}
+
+ares_status_t ares_buf_consume(ares_buf_t *buf, size_t len)
+{
+  size_t remaining_len = ares_buf_len(buf);
+
+  if (remaining_len < len) {
+    return ARES_EBADRESP;
+  }
+
+  buf->offset += len;
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_fetch_be16(ares_buf_t *buf, unsigned short *u16)
+{
+  size_t               remaining_len;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+  unsigned int         u32;
+
+  if (buf == NULL || u16 == NULL || remaining_len < sizeof(*u16)) {
+    return ARES_EBADRESP;
+  }
+
+  /* Do math in an unsigned int in order to prevent warnings due to automatic
+   * conversion by the compiler from short to int during shifts */
+  u32  = ((unsigned int)(ptr[0]) << 8 | (unsigned int)ptr[1]);
+  *u16 = (unsigned short)(u32 & 0xFFFF);
+
+  return ares_buf_consume(buf, sizeof(*u16));
+}
+
+ares_status_t ares_buf_fetch_be32(ares_buf_t *buf, unsigned int *u32)
+{
+  size_t               remaining_len;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+
+  if (buf == NULL || u32 == NULL || remaining_len < sizeof(*u32)) {
+    return ARES_EBADRESP;
+  }
+
+  *u32 = ((unsigned int)(ptr[0]) << 24 | (unsigned int)(ptr[1]) << 16 |
+          (unsigned int)(ptr[2]) << 8 | (unsigned int)(ptr[3]));
+
+  return ares_buf_consume(buf, sizeof(*u32));
+}
+
+ares_status_t ares_buf_fetch_bytes(ares_buf_t *buf, unsigned char *bytes,
+                                   size_t len)
+{
+  size_t               remaining_len;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+
+  if (buf == NULL || bytes == NULL || len == 0 || remaining_len < len) {
+    return ARES_EBADRESP;
+  }
+
+  memcpy(bytes, ptr, len);
+  return ares_buf_consume(buf, len);
+}
+
+ares_status_t ares_buf_fetch_bytes_dup(ares_buf_t *buf, size_t len,
+                                       ares_bool_t     null_term,
+                                       unsigned char **bytes)
+{
+  size_t               remaining_len;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+
+  if (buf == NULL || bytes == NULL || len == 0 || remaining_len < len) {
+    return ARES_EBADRESP;
+  }
+
+  *bytes = ares_malloc(null_term ? len + 1 : len);
+  if (*bytes == NULL) {
+    return ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  memcpy(*bytes, ptr, len);
+  if (null_term) {
+    (*bytes)[len] = 0;
+  }
+  return ares_buf_consume(buf, len);
+}
+
+ares_status_t ares_buf_fetch_str_dup(ares_buf_t *buf, size_t len, char **str)
+{
+  size_t               remaining_len;
+  size_t               i;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+
+  if (buf == NULL || str == NULL || len == 0 || remaining_len < len) {
+    return ARES_EBADRESP;
+  }
+
+  /* Validate string is printable */
+  for (i = 0; i < len; i++) {
+    if (!ares_isprint(ptr[i])) {
+      return ARES_EBADSTR;
+    }
+  }
+
+  *str = ares_malloc(len + 1);
+  if (*str == NULL) {
+    return ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  memcpy(*str, ptr, len);
+  (*str)[len] = 0;
+
+  return ares_buf_consume(buf, len);
+}
+
+ares_status_t ares_buf_fetch_bytes_into_buf(ares_buf_t *buf, ares_buf_t *dest,
+                                            size_t len)
+{
+  size_t               remaining_len;
+  const unsigned char *ptr = ares_buf_fetch(buf, &remaining_len);
+  ares_status_t        status;
+
+  if (buf == NULL || dest == NULL || len == 0 || remaining_len < len) {
+    return ARES_EBADRESP;
+  }
+
+  status = ares_buf_append(dest, ptr, len);
+  if (status != ARES_SUCCESS) {
+    return status;
+  }
+
+  return ares_buf_consume(buf, len);
+}
+
+static ares_bool_t ares_is_whitespace(unsigned char c,
+                                      ares_bool_t   include_linefeed)
+{
+  switch (c) {
+    case '\r':
+    case '\t':
+    case ' ':
+    case '\v':
+    case '\f':
+      return ARES_TRUE;
+    case '\n':
+      return include_linefeed;
+    default:
+      break;
+  }
+  return ARES_FALSE;
+}
+
+size_t ares_buf_consume_whitespace(ares_buf_t *buf,
+                                   ares_bool_t include_linefeed)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  size_t               i;
+
+  if (ptr == NULL) {
+    return 0;
+  }
+
+  for (i = 0; i < remaining_len; i++) {
+    if (!ares_is_whitespace(ptr[i], include_linefeed)) {
+      break;
+    }
+  }
+
+  if (i > 0) {
+    ares_buf_consume(buf, i);
+  }
+  return i;
+}
+
+size_t ares_buf_consume_nonwhitespace(ares_buf_t *buf)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  size_t               i;
+
+  if (ptr == NULL) {
+    return 0;
+  }
+
+  for (i = 0; i < remaining_len; i++) {
+    if (ares_is_whitespace(ptr[i], ARES_TRUE)) {
+      break;
+    }
+  }
+
+  if (i > 0) {
+    ares_buf_consume(buf, i);
+  }
+  return i;
+}
+
+size_t ares_buf_consume_line(ares_buf_t *buf, ares_bool_t include_linefeed)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  size_t               i;
+
+  if (ptr == NULL) {
+    return 0;
+  }
+
+  for (i = 0; i < remaining_len; i++) {
+    if (ptr[i] == '\n') {
+      goto done;
+    }
+  }
+
+done:
+  if (include_linefeed && i < remaining_len && ptr[i] == '\n') {
+    i++;
+  }
+
+  if (i > 0) {
+    ares_buf_consume(buf, i);
+  }
+  return i;
+}
+
+size_t ares_buf_consume_until_charset(ares_buf_t          *buf,
+                                      const unsigned char *charset, size_t len,
+                                      ares_bool_t require_charset)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  size_t               pos;
+  ares_bool_t          found = ARES_FALSE;
+
+  if (ptr == NULL || charset == NULL || len == 0) {
+    return 0;
+  }
+
+  /* Optimize for single character searches */
+  if (len == 1) {
+    const unsigned char *p = memchr(ptr, charset[0], remaining_len);
+    if (p != NULL) {
+      found = ARES_TRUE;
+      pos   = (size_t)(p - ptr);
+    } else {
+      pos = remaining_len;
+    }
+    goto done;
+  }
+
+  for (pos = 0; pos < remaining_len; pos++) {
+    size_t j;
+    for (j = 0; j < len; j++) {
+      if (ptr[pos] == charset[j]) {
+        found = ARES_TRUE;
+        goto done;
+      }
+    }
+  }
+
+done:
+  if (require_charset && !found) {
+    return SIZE_MAX;
+  }
+
+  if (pos > 0) {
+    ares_buf_consume(buf, pos);
+  }
+  return pos;
+}
+
+size_t ares_buf_consume_until_seq(ares_buf_t *buf, const unsigned char *seq,
+                                  size_t len, ares_bool_t require_seq)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  const unsigned char *p;
+  size_t               consume_len = 0;
+
+  if (ptr == NULL || seq == NULL || len == 0) {
+    return 0;
+  }
+
+  p = ares_memmem(ptr, remaining_len, seq, len);
+  if (require_seq && p == NULL) {
+    return SIZE_MAX;
+  }
+
+  if (p != NULL) {
+    consume_len = (size_t)(p - ptr);
+  } else {
+    consume_len = remaining_len;
+  }
+
+  if (consume_len > 0) {
+    ares_buf_consume(buf, consume_len);
+  }
+
+  return consume_len;
+}
+
+size_t ares_buf_consume_charset(ares_buf_t *buf, const unsigned char *charset,
+                                size_t len)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+  size_t               i;
+
+  if (ptr == NULL || charset == NULL || len == 0) {
+    return 0;
+  }
+
+  for (i = 0; i < remaining_len; i++) {
+    size_t j;
+    for (j = 0; j < len; j++) {
+      if (ptr[i] == charset[j]) {
+        break;
+      }
+    }
+    /* Not found */
+    if (j == len) {
+      break;
+    }
+  }
+
+  if (i > 0) {
+    ares_buf_consume(buf, i);
+  }
+  return i;
+}
+
+static void ares_buf_destroy_cb(void *arg)
+{
+  ares_buf_t **buf = arg;
+  ares_buf_destroy(*buf);
+}
+
+static ares_bool_t ares_buf_split_isduplicate(ares_array_t        *arr,
+                                              const unsigned char *val,
+                                              size_t               len,
+                                              ares_buf_split_t     flags)
+{
+  size_t i;
+  size_t num = ares_array_len(arr);
+
+  for (i = 0; i < num; i++) {
+    ares_buf_t         **bufptr = ares_array_at(arr, i);
+    const ares_buf_t    *buf    = *bufptr;
+    size_t               plen   = 0;
+    const unsigned char *ptr    = ares_buf_peek(buf, &plen);
+
+    /* Can't be duplicate if lengths mismatch */
+    if (plen != len) {
+      continue;
+    }
+
+    if (flags & ARES_BUF_SPLIT_CASE_INSENSITIVE) {
+      if (ares_memeq_ci(ptr, val, len)) {
+        return ARES_TRUE;
+      }
+    } else {
+      if (ares_memeq(ptr, val, len)) {
+        return ARES_TRUE;
+      }
+    }
+  }
+
+  return ARES_FALSE;
+}
+
+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)
+{
+  ares_status_t status = ARES_SUCCESS;
+  ares_bool_t   first  = ARES_TRUE;
+
+  if (buf == NULL || delims == NULL || delims_len == 0 || arr == NULL) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  *arr = ares_array_create(sizeof(ares_buf_t *), ares_buf_destroy_cb);
+  if (*arr == NULL) {
+    status = ARES_ENOMEM;
+    goto done;
+  }
+
+  while (ares_buf_len(buf)) {
+    size_t               len = 0;
+    const unsigned char *ptr;
+
+    if (first) {
+      /* No delimiter yet, just tag the start */
+      ares_buf_tag(buf);
+    } else {
+      if (flags & ARES_BUF_SPLIT_KEEP_DELIMS) {
+        /* tag then eat delimiter so its first byte in buffer */
+        ares_buf_tag(buf);
+        ares_buf_consume(buf, 1);
+      } else {
+        /* throw away delimiter */
+        ares_buf_consume(buf, 1);
+        ares_buf_tag(buf);
+      }
+    }
+
+    if (max_sections && ares_array_len(*arr) >= max_sections - 1) {
+      ares_buf_consume(buf, ares_buf_len(buf));
+    } else {
+      ares_buf_consume_until_charset(buf, delims, delims_len, ARES_FALSE);
+    }
+
+    ptr = ares_buf_tag_fetch(buf, &len);
+
+    /* Shouldn't be possible */
+    if (ptr == NULL) {
+      status = ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+      goto done;
+    }
+
+    if (flags & ARES_BUF_SPLIT_LTRIM) {
+      size_t i;
+      for (i = 0; i < len; i++) {
+        if (!ares_is_whitespace(ptr[i], ARES_TRUE)) {
+          break;
+        }
+      }
+      ptr += i;
+      len -= i;
+    }
+
+    if (flags & ARES_BUF_SPLIT_RTRIM) {
+      while (len > 0 && ares_is_whitespace(ptr[len - 1], ARES_TRUE)) {
+        len--;
+      }
+    }
+
+    if (len != 0 || flags & ARES_BUF_SPLIT_ALLOW_BLANK) {
+      ares_buf_t *data;
+
+      if (!(flags & ARES_BUF_SPLIT_NO_DUPLICATES) ||
+          !ares_buf_split_isduplicate(*arr, ptr, len, flags)) {
+        /* Since we don't allow const buffers of 0 length, and user wants
+         * 0-length buffers, swap what we do here */
+        if (len) {
+          data = ares_buf_create_const(ptr, len);
+        } else {
+          data = ares_buf_create();
+        }
+
+        if (data == NULL) {
+          status = ARES_ENOMEM;
+          goto done;
+        }
+
+        status = ares_array_insertdata_last(*arr, &data);
+        if (status != ARES_SUCCESS) {
+          ares_buf_destroy(data);
+          goto done;
+        }
+      }
+    }
+
+    first = ARES_FALSE;
+  }
+
+done:
+  if (status != ARES_SUCCESS) {
+    ares_array_destroy(*arr);
+    *arr = NULL;
+  }
+
+  return status;
+}
+
+static void ares_free_split_array(void *arg)
+{
+  void **ptr = arg;
+  ares_free(*ptr);
+}
+
+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)
+{
+  ares_status_t status;
+  ares_array_t *split = NULL;
+  size_t        i;
+  size_t        len;
+
+  if (arr == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  *arr = NULL;
+
+  status = ares_buf_split(buf, delims, delims_len, flags, max_sections, &split);
+  if (status != ARES_SUCCESS) {
+    goto done;
+  }
+
+  *arr = ares_array_create(sizeof(char *), ares_free_split_array);
+  if (*arr == NULL) {
+    status = ARES_ENOMEM;
+    goto done;
+  }
+
+  len = ares_array_len(split);
+  for (i = 0; i < len; i++) {
+    ares_buf_t **bufptr = ares_array_at(split, i);
+    ares_buf_t  *lbuf   = *bufptr;
+    char        *str    = NULL;
+
+    status = ares_buf_fetch_str_dup(lbuf, ares_buf_len(lbuf), &str);
+    if (status != ARES_SUCCESS) {
+      goto done;
+    }
+
+    status = ares_array_insertdata_last(*arr, &str);
+    if (status != ARES_SUCCESS) {
+      ares_free(str);
+      goto done;
+    }
+  }
+
+done:
+  ares_array_destroy(split);
+  if (status != ARES_SUCCESS) {
+    ares_array_destroy(*arr);
+    *arr = NULL;
+  }
+  return status;
+}
+
+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)
+{
+  ares_status_t status;
+  ares_array_t *arr = NULL;
+
+  if (strs == NULL || nstrs == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  *strs  = NULL;
+  *nstrs = 0;
+
+  status = ares_buf_split_str_array(buf, delims, delims_len, flags,
+                                    max_sections, &arr);
+
+  if (status != ARES_SUCCESS) {
+    goto done;
+  }
+
+done:
+  if (status == ARES_SUCCESS) {
+    *strs = ares_array_finish(arr, nstrs);
+  } else {
+    ares_array_destroy(arr);
+  }
+  return status;
+}
+
+ares_bool_t ares_buf_begins_with(const ares_buf_t    *buf,
+                                 const unsigned char *data, size_t data_len)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+
+  if (ptr == NULL || data == NULL || data_len == 0) {
+    return ARES_FALSE;
+  }
+
+  if (data_len > remaining_len) {
+    return ARES_FALSE;
+  }
+
+  if (memcmp(ptr, data, data_len) != 0) {
+    return ARES_FALSE;
+  }
+
+  return ARES_TRUE;
+}
+
+size_t ares_buf_len(const ares_buf_t *buf)
+{
+  if (buf == NULL) {
+    return 0;
+  }
+
+  return buf->data_len - buf->offset;
+}
+
+const unsigned char *ares_buf_peek(const ares_buf_t *buf, size_t *len)
+{
+  return ares_buf_fetch(buf, len);
+}
+
+ares_status_t ares_buf_peek_byte(const ares_buf_t *buf, unsigned char *b)
+{
+  size_t               remaining_len = 0;
+  const unsigned char *ptr           = ares_buf_fetch(buf, &remaining_len);
+
+  if (buf == NULL || b == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (remaining_len == 0) {
+    return ARES_EBADRESP;
+  }
+  *b = ptr[0];
+  return ARES_SUCCESS;
+}
+
+size_t ares_buf_get_position(const ares_buf_t *buf)
+{
+  if (buf == NULL) {
+    return 0;
+  }
+  return buf->offset;
+}
+
+ares_status_t ares_buf_set_position(ares_buf_t *buf, size_t idx)
+{
+  if (buf == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (idx > buf->data_len) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  buf->offset = idx;
+  return ARES_SUCCESS;
+}
+
+static ares_status_t
+  ares_buf_parse_dns_binstr_int(ares_buf_t *buf, size_t remaining_len,
+                                unsigned char **bin, size_t *bin_len,
+                                ares_bool_t validate_printable)
+{
+  unsigned char len;
+  ares_status_t status = ARES_EBADRESP;
+  ares_buf_t   *binbuf = NULL;
+
+  if (buf == NULL) {
+    return ARES_EFORMERR;
+  }
+
+  if (remaining_len == 0) {
+    return ARES_EBADRESP;
+  }
+
+  binbuf = ares_buf_create();
+  if (binbuf == NULL) {
+    return ARES_ENOMEM;
+  }
+
+  status = ares_buf_fetch_bytes(buf, &len, 1);
+  if (status != ARES_SUCCESS) {
+    goto done; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  remaining_len--;
+
+  if (len > remaining_len) {
+    status = ARES_EBADRESP;
+    goto done;
+  }
+
+  if (len) {
+    /* When used by the _str() parser, it really needs to be validated to
+     * be a valid printable ascii string.  Do that here */
+    if (validate_printable && ares_buf_len(buf) >= len) {
+      size_t      mylen;
+      const char *data = (const char *)ares_buf_peek(buf, &mylen);
+      if (!ares_str_isprint(data, len)) {
+        status = ARES_EBADSTR;
+        goto done;
+      }
+    }
+
+    if (bin != NULL) {
+      status = ares_buf_fetch_bytes_into_buf(buf, binbuf, len);
+    } else {
+      status = ares_buf_consume(buf, len);
+    }
+  }
+
+done:
+  if (status != ARES_SUCCESS) {
+    ares_buf_destroy(binbuf);
+  } else {
+    if (bin != NULL) {
+      size_t mylen = 0;
+      /* NOTE: we use ares_buf_finish_str() here as we guarantee NULL
+       *       Termination even though we are technically returning binary data.
+       */
+      *bin     = (unsigned char *)ares_buf_finish_str(binbuf, &mylen);
+      *bin_len = mylen;
+    }
+  }
+
+  return status;
+}
+
+ares_status_t ares_buf_parse_dns_binstr(ares_buf_t *buf, size_t remaining_len,
+                                        unsigned char **bin, size_t *bin_len)
+{
+  return ares_buf_parse_dns_binstr_int(buf, remaining_len, bin, bin_len,
+                                       ARES_FALSE);
+}
+
+ares_status_t ares_buf_parse_dns_str(ares_buf_t *buf, size_t remaining_len,
+                                     char **str)
+{
+  size_t len;
+
+  return ares_buf_parse_dns_binstr_int(buf, remaining_len,
+                                       (unsigned char **)str, &len, ARES_TRUE);
+}
+
+ares_status_t ares_buf_append_num_dec(ares_buf_t *buf, size_t num, size_t len)
+{
+  size_t i;
+  size_t mod;
+
+  if (len == 0) {
+    len = ares_count_digits(num);
+  }
+
+  mod = ares_pow(10, len);
+
+  for (i = len; i > 0; i--) {
+    size_t        digit = (num % mod);
+    ares_status_t status;
+
+    mod /= 10;
+
+    /* Silence coverity.  Shouldn't be possible since we calculate it above */
+    if (mod == 0) {
+      return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+    }
+
+    digit  /= mod;
+    status  = ares_buf_append_byte(buf, '0' + (unsigned char)(digit & 0xFF));
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+  }
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_append_num_hex(ares_buf_t *buf, size_t num, size_t len)
+{
+  size_t                     i;
+  static const unsigned char hexbytes[] = "0123456789ABCDEF";
+
+  if (len == 0) {
+    len = ares_count_hexdigits(num);
+  }
+
+  for (i = len; i > 0; i--) {
+    ares_status_t status;
+    status = ares_buf_append_byte(buf, hexbytes[(num >> ((i - 1) * 4)) & 0xF]);
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+  }
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_append_str(ares_buf_t *buf, const char *str)
+{
+  return ares_buf_append(buf, (const unsigned char *)str, ares_strlen(str));
+}
+
+static ares_status_t ares_buf_hexdump_line(ares_buf_t *buf, size_t idx,
+                                           const unsigned char *data,
+                                           size_t               len)
+{
+  size_t        i;
+  ares_status_t status;
+
+  /* Address */
+  status = ares_buf_append_num_hex(buf, idx, 6);
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  /* | */
+  status = ares_buf_append_str(buf, " | ");
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  for (i = 0; i < 16; i++) {
+    if (i >= len) {
+      status = ares_buf_append_str(buf, "  ");
+    } else {
+      status = ares_buf_append_num_hex(buf, data[i], 2);
+    }
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+
+    status = ares_buf_append_byte(buf, ' ');
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+  }
+
+  /* | */
+  status = ares_buf_append_str(buf, " | ");
+  if (status != ARES_SUCCESS) {
+    return status; /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  for (i = 0; i < 16; i++) {
+    if (i >= len) {
+      break;
+    }
+    status = ares_buf_append_byte(buf, ares_isprint(data[i]) ? data[i] : '.');
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+  }
+
+  return ares_buf_append_byte(buf, '\n');
+}
+
+ares_status_t ares_buf_hexdump(ares_buf_t *buf, const unsigned char *data,
+                               size_t len)
+{
+  size_t i;
+
+  /* Each line is 16 bytes */
+  for (i = 0; i < len; i += 16) {
+    ares_status_t status;
+    status = ares_buf_hexdump_line(buf, i, data + i, len - i);
+    if (status != ARES_SUCCESS) {
+      return status; /* LCOV_EXCL_LINE: OutOfMemory */
+    }
+  }
+
+  return ARES_SUCCESS;
+}
+
+ares_status_t ares_buf_load_file(const char *filename, ares_buf_t *buf)
+{
+  FILE          *fp        = NULL;
+  unsigned char *ptr       = NULL;
+  size_t         len       = 0;
+  size_t         ptr_len   = 0;
+  long           ftell_len = 0;
+  ares_status_t  status;
+
+  if (filename == NULL || buf == NULL) {
+    return ARES_EFORMERR; /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  fp = fopen(filename, "rb");
+  if (fp == NULL) {
+    int error = errno;
+    switch (error) {
+      case ENOENT:
+      case ESRCH:
+        status = ARES_ENOTFOUND;
+        goto done;
+      default:
+        DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n", error,
+                       strerror(error)));
+        DEBUGF(fprintf(stderr, "Error opening file: %s\n", filename));
+        status = ARES_EFILE;
+        goto done;
+    }
+  }
+
+  /* Get length portably, fstat() is POSIX, not C */
+  if (fseek(fp, 0, SEEK_END) != 0) {
+    status = ARES_EFILE; /* LCOV_EXCL_LINE: DefensiveCoding */
+    goto done;           /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  ftell_len = ftell(fp);
+  if (ftell_len < 0) {
+    status = ARES_EFILE; /* LCOV_EXCL_LINE: DefensiveCoding */
+    goto done;           /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+  len = (size_t)ftell_len;
+
+  if (fseek(fp, 0, SEEK_SET) != 0) {
+    status = ARES_EFILE; /* LCOV_EXCL_LINE: DefensiveCoding */
+    goto done;           /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  if (len == 0) {
+    status = ARES_SUCCESS; /* LCOV_EXCL_LINE: DefensiveCoding */
+    goto done;             /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  /* Read entire data into buffer */
+  ptr_len = len;
+  ptr     = ares_buf_append_start(buf, &ptr_len);
+  if (ptr == NULL) {
+    status = ARES_ENOMEM; /* LCOV_EXCL_LINE: OutOfMemory */
+    goto done;            /* LCOV_EXCL_LINE: OutOfMemory */
+  }
+
+  ptr_len = fread(ptr, 1, len, fp);
+  if (ptr_len != len) {
+    status = ARES_EFILE; /* LCOV_EXCL_LINE: DefensiveCoding */
+    goto done;           /* LCOV_EXCL_LINE: DefensiveCoding */
+  }
+
+  ares_buf_append_finish(buf, len);
+  status = ARES_SUCCESS;
+
+done:
+  if (fp != NULL) {
+    fclose(fp);
+  }
+  return status;
+}