NAME¶

lwres_getrrsetbyname, lwres_freerrset - retrieve DNS records

SYNOPSIS¶

#include <lwres/netdb.h>

int lwres_getrrsetbyname(const char *hostname, unsigned int rdclass, unsigned int rdtype, unsigned int flags, struct rrsetinfo **res);

void lwres_freerrset(struct rrsetinfo *rrset);

The following structures are used:

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 */
};

DESCRIPTION¶

lwres_getrrsetbyname() gets a set of resource records associated with a hostname, class, and type. hostname is a pointer a to null-terminated string. The flags field is currently unused and must be zero.

After a successful call to lwres_getrrsetbyname(), *res is a pointer to an rrsetinfo structure, containing a list of one or more rdatainfo structures containing resource records and potentially another list of rdatainfo 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.

All of the information returned by lwres_getrrsetbyname() 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 lwres_getrrsetbyname() is released by lwres_freerrset(). rrset is a pointer to a struct rrset created by a call to lwres_getrrsetbyname().

RETURN VALUES¶

lwres_getrrsetbyname() returns zero on success, and one of the following error codes if an error occurred:

ERRSET_NONAME

ERRSET_NODATA

ERRSET_NOMEMORY

ERRSET_INVAL

ERRSET_FAIL

SEE ALSO¶

lwres(3).

AUTHOR¶

Internet Systems Consortium, Inc.

COPYRIGHT¶

Copyright © 2000, 2001, 2004, 2005, 2007, 2014-2016, 2018 Internet Systems Consortium, Inc. ("ISC")