Copyright 1998 by the Massachusetts Institute of Technology.
SPDX-License-Identifier: MIT

ares_parse_txt_reply - Parse a reply to a DNS query of type TXT

#include <ares.h>

int ares_parse_txt_reply(const unsigned char* abuf, int alen,
 struct ares_txt_reply **txt_out);

int ares_parse_txt_reply_ext(const unsigned char* abuf, int alen,
 struct ares_txt_ext **txt_out);

The ares_parse_txt_reply(3) and ares_parse_txt_reply_ext(3) functions parse the response to a query of type TXT into a linked list (one element per sub-string) of "struct ares_txt_reply" " (" "struct ares_txt_ext" ")" The parameters abuf and alen give the contents of the response. The result is stored in allocated memory and a pointer to it stored into the variable pointed to by txt_out . It is the caller's responsibility to free the resulting txt_out structure when it is no longer needed using the function ares_free_data(3). The structure ares_txt_reply contains the following fields:

struct ares_txt_reply {
 struct ares_txt_reply *next;
 unsigned int length;
 unsigned char *txt;
};

The structure ares_txt_ext contains the following fields:

struct ares_txt_ext {
 struct ares_txt_ext *next;
 unsigned int length;
 unsigned char *txt;
 unsigned char record_start;
};

The record_start field in struct ares_txt_ext is 1 if this structure is a start of a TXT record, and 0 if the structure is a continuation of a previous record. The linked list of the struct ares_txt_ext will have at least one item with record_start equal to 1, and may have some items with record_start equal to 0 between them. These sequences of struct ares_txt_ext (starting from the item with record_start equal to 1, and ending right before the record start item) may be treated as either components of a single TXT record or as a multi-parted TXT record, depending on particular use case. "ares_parse_txt_reply" " (" "ares_parse_txt_reply_ext" ")" can return any of the following values:

15 ARES_SUCCESS The response was successfully parsed.

15 ARES_EBADRESP The response was malformatted.

15 ARES_ENODATA The response did not contain an answer to the query.

15 ARES_ENOMEM Memory was exhausted.

This function was first introduced in c-ares version 1.7.0. ares_query (3) ares_free_data (3)