plucky (3) ares_parse_txt_reply.3.gz

NAME

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

SYNOPSIS

       #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);

DESCRIPTION

       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.

RETURN VALUES

       ares_parse_txt_reply (ares_parse_txt_reply_ext) can return any of the following values:

       ARES_SUCCESS   The response was successfully parsed.

       ARES_EBADRESP  The response was malformatted.

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

       ARES_ENOMEM    Memory was exhausted.

AVAILABILITY

       This function was first introduced in c-ares version 1.7.0.

SEE ALSO

       ares_query(3) ares_free_data(3)

                                                 27 October 2009                         ARES_PARSE_TXT_REPLY(3)