lwres_getrrsetbyname.html [plain text]
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<HTML
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><TITLE
>lwres_getrrsetbyname</TITLE
><META
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><H1
><A
NAME="AEN1"
>lwres_getrrsetbyname</A
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN8"
></A
><H2
>Name</H2
>lwres_getrrsetbyname, lwres_freerrset -- retrieve DNS records</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN12"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN13"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include <lwres/netdb.h></PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int
lwres_getrrsetbyname</CODE
>(const char *hostname, unsigned int rdclass, unsigned int rdtype, unsigned int flags, struct rrsetinfo **res);</CODE
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>void
lwres_freerrset</CODE
>(struct rrsetinfo *rrset);</CODE
></P
><P
></P
></DIV
><P
>The following structures are used:
<PRE
CLASS="PROGRAMLISTING"
>struct rdatainfo {
unsigned int rdi_length; /* length of data */
unsigned char *rdi_data; /* record data */
};
struct rrsetinfo {
unsigned int rri_flags; /* RRSET_VALIDATED... */
unsigned int rri_rdclass; /* class number */
unsigned int rri_rdtype; /* RR type number */
unsigned int rri_ttl; /* time to live */
unsigned int rri_nrdatas; /* size of rdatas array */
unsigned int rri_nsigs; /* size of sigs array */
char *rri_name; /* canonical name */
struct rdatainfo *rri_rdatas; /* individual records */
struct rdatainfo *rri_sigs; /* individual signatures */
};</PRE
></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN29"
></A
><H2
>DESCRIPTION</H2
><P
><TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>
gets a set of resource records associated with a
<TT
CLASS="PARAMETER"
><I
>hostname</I
></TT
>,
<TT
CLASS="PARAMETER"
><I
>class</I
></TT
>,
and
<TT
CLASS="PARAMETER"
><I
>type</I
></TT
>.
<TT
CLASS="PARAMETER"
><I
>hostname</I
></TT
>
is
a pointer a to null-terminated string. The
<TT
CLASS="PARAMETER"
><I
>flags</I
></TT
>
field is currently unused and must be zero.</P
><P
>After a successful call to
<TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>,
<TT
CLASS="PARAMETER"
><I
>*res</I
></TT
>
is a pointer to an
<SPAN
CLASS="TYPE"
>rrsetinfo</SPAN
>
structure, containing a list of one or more
<SPAN
CLASS="TYPE"
>rdatainfo</SPAN
>
structures containing resource records and potentially another list of
<SPAN
CLASS="TYPE"
>rdatainfo</SPAN
>
structures containing SIG resource records
associated with those records.
The members
<TT
CLASS="CONSTANT"
>rri_rdclass</TT
>
and
<TT
CLASS="CONSTANT"
>rri_rdtype</TT
>
are copied from the parameters.
<TT
CLASS="CONSTANT"
>rri_ttl</TT
>
and
<TT
CLASS="CONSTANT"
>rri_name</TT
>
are properties of the obtained rrset.
The resource records contained in
<TT
CLASS="CONSTANT"
>rri_rdatas</TT
>
and
<TT
CLASS="CONSTANT"
>rri_sigs</TT
>
are in uncompressed DNS wire format.
Properties of the rdataset are represented in the
<TT
CLASS="CONSTANT"
>rri_flags</TT
>
bitfield. If the RRSET_VALIDATED bit is set, the data has been DNSSEC
validated and the signatures verified. </P
><P
>All of the information returned by
<TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>
is dynamically allocated: the
<TT
CLASS="CONSTANT"
>rrsetinfo</TT
>
and
<TT
CLASS="CONSTANT"
>rdatainfo</TT
>
structures,
and the canonical host name strings pointed to by the
<TT
CLASS="CONSTANT"
>rrsetinfo</TT
>structure.
Memory allocated for the dynamically allocated structures created by
a successful call to
<TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>
is released by
<TT
CLASS="FUNCTION"
>lwres_freerrset()</TT
>.
<TT
CLASS="PARAMETER"
><I
>rrset</I
></TT
>
is a pointer to a
<SPAN
CLASS="TYPE"
>struct rrset</SPAN
>
created by a call to
<TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>. </P
><P
></P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN62"
></A
><H2
>RETURN VALUES</H2
><P
><TT
CLASS="FUNCTION"
>lwres_getrrsetbyname()</TT
>
returns zero on success, and one of the following error
codes if an error occurred:
<P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="CONSTANT"
>ERRSET_NONAME</TT
></DT
><DD
><P
>the name does not exist</P
></DD
><DT
><TT
CLASS="CONSTANT"
>ERRSET_NODATA</TT
></DT
><DD
><P
>the name exists, but does not have data of the desired type</P
></DD
><DT
><TT
CLASS="CONSTANT"
>ERRSET_NOMEMORY</TT
></DT
><DD
><P
>memory could not be allocated</P
></DD
><DT
><TT
CLASS="CONSTANT"
>ERRSET_INVAL</TT
></DT
><DD
><P
>a parameter is invalid</P
></DD
><DT
><TT
CLASS="CONSTANT"
>ERRSET_FAIL</TT
></DT
><DD
><P
>other failure</P
></DD
><DT
><TT
CLASS="CONSTANT"
></TT
></DT
><DD
><P
></P
></DD
></DL
></DIV
> </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN97"
></A
><H2
>SEE ALSO</H2
><P
><SPAN
CLASS="CITEREFENTRY"
><SPAN
CLASS="REFENTRYTITLE"
>lwres</SPAN
>(3)</SPAN
>.</P
></DIV
></BODY
></HTML
>