lwres_getrrsetbyname.3

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.\" Copyright (C) 2000, 2001 Internet Software Consortium.
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.\" $Id: lwres_getrrsetbyname.3,v 1.11.2.1.8.5 2005/10/13 02:33:53 marka Exp $
.\"
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.TH "LWRES_GETRRSETBYNAME" "3" "Oct 18, 2000" "BIND9" "BIND9"
.\" disable hyphenation
.nh
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.SH "NAME"
lwres_getrrsetbyname, lwres_freerrset \- retrieve DNS records
.SH "SYNOPSIS"
.nf
#include <lwres/netdb.h>
.fi
.HP 25
\fBint\ \fBlwres_getrrsetbyname\fR\fR\fB(\fR\fBconst\ char\ *hostname\fR\fB, \fR\fBunsigned\ int\ rdclass\fR\fB, \fR\fBunsigned\ int\ rdtype\fR\fB, \fR\fBunsigned\ int\ flags\fR\fB, \fR\fBstruct\ rrsetinfo\ **res\fR\fB);\fR
.HP 21
\fBvoid\ \fBlwres_freerrset\fR\fR\fB(\fR\fBstruct\ rrsetinfo\ *rrset\fR\fB);\fR
.PP
The following structures are used:
.sp
.nf
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 */
};
.fi
.sp
.SH "DESCRIPTION"
.PP
\fBlwres_getrrsetbyname()\fR
gets a set of resource records associated with a
\fIhostname\fR,
\fIclass\fR, and
\fItype\fR.
\fIhostname\fR
is a pointer a to null\-terminated string. The
\fIflags\fR
field is currently unused and must be zero.
.PP
After a successful call to
\fBlwres_getrrsetbyname()\fR,
\fI*res\fR
is a pointer to an
\fBrrsetinfo\fR
structure, containing a list of one or more
\fBrdatainfo\fR
structures containing resource records and potentially another list of
\fBrdatainfo\fR
structures containing SIG resource records associated with those records. The members
\fBrri_rdclass\fR
and
\fBrri_rdtype\fR
are copied from the parameters.
\fBrri_ttl\fR
and
\fBrri_name\fR
are properties of the obtained rrset. The resource records contained in
\fBrri_rdatas\fR
and
\fBrri_sigs\fR
are in uncompressed DNS wire format. Properties of the rdataset are represented in the
\fBrri_flags\fR
bitfield. If the RRSET_VALIDATED bit is set, the data has been DNSSEC validated and the signatures verified.
.PP
All of the information returned by
\fBlwres_getrrsetbyname()\fR
is dynamically allocated: the
\fBrrsetinfo\fR
and
\fBrdatainfo\fR
structures, and the canonical host name strings pointed to by the
\fBrrsetinfo\fRstructure. Memory allocated for the dynamically allocated structures created by a successful call to
\fBlwres_getrrsetbyname()\fR
is released by
\fBlwres_freerrset()\fR.
\fIrrset\fR
is a pointer to a
\fBstruct rrset\fR
created by a call to
\fBlwres_getrrsetbyname()\fR.
.PP
.SH "RETURN VALUES"
.PP
\fBlwres_getrrsetbyname()\fR
returns zero on success, and one of the following error codes if an error occurred:
.TP
\fBERRSET_NONAME\fR
the name does not exist
.TP
\fBERRSET_NODATA\fR
the name exists, but does not have data of the desired type
.TP
\fBERRSET_NOMEMORY\fR
memory could not be allocated
.TP
\fBERRSET_INVAL\fR
a parameter is invalid
.TP
\fBERRSET_FAIL\fR
other failure
.TP
.SH "SEE ALSO"
.PP
\fBlwres\fR(3).