lwres_getrrsetbyname.3

bind 9.3结合mysql数据库

.\" Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
.\" Copyright (C) 2000, 2001  Internet Software Consortium.
.\"
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.\" $Id: lwres_getrrsetbyname.3,v 1.11.2.1.8.1 2004/03/06 07:41:43 marka Exp $
.\"
.TH "LWRES_GETRRSETBYNAME" "3" "Oct 18, 2000" "BIND9" ""
.SH NAME
lwres_getrrsetbyname, lwres_freerrset \- retrieve DNS records
.SH SYNOPSIS
\fB#include <lwres/netdb.h>
.sp
.na
int
lwres_getrrsetbyname(const char *hostname, unsigned int rdclass, unsigned int rdtype, unsigned int flags, struct rrsetinfo **res);
.ad
.sp
.na
void
lwres_freerrset(struct rrsetinfo *rrset);
.ad
\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 */
};
.sp
.fi
.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
rri_rdclass
and
rri_rdtype
are copied from the parameters.
rri_ttl
and
rri_name
are properties of the obtained rrset.
The resource records contained in
rri_rdatas
and
rri_sigs
are in uncompressed DNS wire format.
Properties of the rdataset are represented in the
rri_flags
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
rrsetinfo
and
rdatainfo
structures,
and the canonical host name strings pointed to by the
rrsetinfostructure.
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
\fB\fR
.SH "SEE ALSO"
.PP
\fBlwres\fR(3).