zone.c

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/* zone.c
 *
 * Functions for ldns_zone structure
 * a Net::DNS like library for C
 *
 * (c) NLnet Labs, 2005-2006
 * See the file LICENSE for the license
 */
#include <ldns/config.h>
 
#include <ldns/ldns.h>
 
#include <strings.h>
#include <limits.h>
 
ldns_rr *
ldns_zone_soa(const ldns_zone *z)
{
        return z->_soa;
}
 
size_t
ldns_zone_rr_count(const ldns_zone *z)
{
        return ldns_rr_list_rr_count(z->_rrs);
}
 
void
ldns_zone_set_soa(ldns_zone *z, ldns_rr *soa)
{
        z->_soa = soa;
}
 
ldns_rr_list *
ldns_zone_rrs(const ldns_zone *z)
{
        return z->_rrs;
}
 
void
ldns_zone_set_rrs(ldns_zone *z, ldns_rr_list *rrlist)
{
        z->_rrs = rrlist;
}
 
bool
ldns_zone_push_rr_list(ldns_zone *z, const ldns_rr_list *list)
{
        return ldns_rr_list_cat(ldns_zone_rrs(z), list);
}
 
bool
ldns_zone_push_rr(ldns_zone *z, ldns_rr *rr)
{
        return ldns_rr_list_push_rr(ldns_zone_rrs(z), rr);
}
 
 
/*
 * Get the list of glue records in a zone
 * XXX: there should be a way for this to return error, other than NULL, 
 *      since NULL is a valid return
 */
ldns_rr_list *
ldns_zone_glue_rr_list(const ldns_zone *z)
{
        /* when do we find glue? It means we find an IP address
         * (AAAA/A) for a nameserver listed in the zone
         *
         * Alg used here:
         * first find all the zonecuts (NS records)
         * find all the AAAA or A records (can be done it the 
         * above loop).
         *
         * Check if the aaaa/a list are subdomains under the
         * NS domains.
         * If yes -> glue, if no -> not glue
         */
 
        ldns_rr_list *zone_cuts;
        ldns_rr_list *addr;
        ldns_rr_list *glue;
        ldns_rr *r, *ns, *a;
        ldns_rdf *dname_a, *ns_owner;
        size_t i,j;
 
        zone_cuts = NULL;
        addr = NULL;
        glue = NULL;
 
        /* we cannot determine glue in a 'zone' without a SOA */
        if (!ldns_zone_soa(z)) {
                return NULL;
        }
 
        zone_cuts = ldns_rr_list_new();
        if (!zone_cuts) goto memory_error;
        addr = ldns_rr_list_new();
        if (!addr) goto memory_error;
        glue = ldns_rr_list_new();
        if (!glue) goto memory_error;
 
        for(i = 0; i < ldns_zone_rr_count(z); i++) {
                r = ldns_rr_list_rr(ldns_zone_rrs(z), i);
                if (ldns_rr_get_type(r) == LDNS_RR_TYPE_A ||
                                ldns_rr_get_type(r) == LDNS_RR_TYPE_AAAA) {
                        /* possibly glue */
                        if (!ldns_rr_list_push_rr(addr, r)) goto memory_error;
                        continue;
                }
                if (ldns_rr_get_type(r) == LDNS_RR_TYPE_NS) {
                        /* multiple zones will end up here -
                         * for now; not a problem
                         */
                        /* don't add NS records for the current zone itself */
                        if (ldns_rdf_compare(ldns_rr_owner(r), 
                                                ldns_rr_owner(ldns_zone_soa(z))) != 0) {
                                if (!ldns_rr_list_push_rr(zone_cuts, r)) goto memory_error;
                        }
                        continue;
                }
        }
 
        /* will sorting make it quicker ?? */
        for(i = 0; i < ldns_rr_list_rr_count(zone_cuts); i++) {
                ns = ldns_rr_list_rr(zone_cuts, i);
                ns_owner = ldns_rr_owner(ns);
 
                for(j = 0; j < ldns_rr_list_rr_count(addr); j++) {
                        a = ldns_rr_list_rr(addr, j);
                        dname_a = ldns_rr_owner(a);
 
                        if (ldns_dname_is_subdomain(dname_a, ns_owner) ||
                                ldns_dname_compare(dname_a, ns_owner) == 0) {
                                /* GLUE! */
                                if (!ldns_rr_list_push_rr(glue, a)) goto memory_error;
                        }
                }
        }
        
        ldns_rr_list_free(addr);
        ldns_rr_list_free(zone_cuts);
 
        if (ldns_rr_list_rr_count(glue) == 0) {
                ldns_rr_list_free(glue);
                return NULL;
        } else {
                return glue;
        }
 
memory_error:
        if (zone_cuts) {
                LDNS_FREE(zone_cuts);
        }
        if (addr) {
                ldns_rr_list_free(addr);
        }
        if (glue) {
                ldns_rr_list_free(glue);
        }
        return NULL;
}
 
ldns_zone *
ldns_zone_new(void)
{
        ldns_zone *z;
 
        z = LDNS_MALLOC(ldns_zone);
        if (!z) {
                return NULL;
        }
 
        z->_rrs = ldns_rr_list_new();
        if (!z->_rrs) {
                LDNS_FREE(z);
                return NULL;
        }
        ldns_zone_set_soa(z, NULL);
        return z;
}
 
/* we recognize:
 * $TTL, $ORIGIN
 */
ldns_status
ldns_zone_new_frm_fp(ldns_zone **z, FILE *fp, const ldns_rdf *origin, uint32_t ttl, ldns_rr_class c)
{
        return ldns_zone_new_frm_fp_l(z, fp, origin, ttl, c, NULL);
}
 
ldns_status _ldns_rr_new_frm_fp_l_internal(ldns_rr **newrr, FILE *fp,
                uint32_t *default_ttl, ldns_rdf **origin, ldns_rdf **prev,
                int *line_nr, bool *explicit_ttl);
 
/* XXX: class is never used */
ldns_status
ldns_zone_new_frm_fp_l(ldns_zone **z, FILE *fp, const ldns_rdf *origin,
        uint32_t default_ttl, ldns_rr_class ATTR_UNUSED(c), int *line_nr)
{
        ldns_zone *newzone;
        ldns_rr *rr, *prev_rr = NULL;
        uint32_t my_ttl;
        ldns_rdf *my_origin;
        ldns_rdf *my_prev;
        bool soa_seen = false;  /* 2 soa are an error */
        ldns_status s;
        ldns_status ret;
        /* RFC 1035 Section 5.1, says 'Omitted class and TTL values are default
         * to the last explicitly stated values.'
         */
        bool ttl_from_TTL = false;
        bool explicit_ttl = false;
 
        /* most cases of error are memory problems */
        ret = LDNS_STATUS_MEM_ERR;
 
        newzone = NULL;
        my_origin = NULL;
        my_prev = NULL;
 
        my_ttl    = default_ttl;
        
        if (origin) {
                my_origin = ldns_rdf_clone(origin);
                if (!my_origin) goto error;
                /* also set the prev */
                my_prev   = ldns_rdf_clone(origin);
                if (!my_prev) goto error;
        }
 
        newzone = ldns_zone_new();
        if (!newzone) goto error;
 
        while(!feof(fp)) {
                /* If ttl came from $TTL line, then it should be the default.
                 * (RFC 2308 Section 4)
                 * Otherwise it "defaults to the last explicitly stated value"
                 * (RFC 1035 Section 5.1)
                 */
                if (ttl_from_TTL)
                        my_ttl = default_ttl;
                s = _ldns_rr_new_frm_fp_l_internal(&rr, fp, &my_ttl, &my_origin,
                                &my_prev, line_nr, &explicit_ttl);
                switch (s) {
                case LDNS_STATUS_OK:
                        if (explicit_ttl) {
                                if (!ttl_from_TTL) {
                                        /* No $TTL, so ttl "defaults to the
                                         * last explicitly stated value"
                                         * (RFC 1035 Section 5.1)
                                         */
                                        my_ttl = ldns_rr_ttl(rr);
                                }
                        /* When ttl is implicit, try to adhere to the rules as
                         * much as possible. (also for compatibility with bind)
                         * This was changed when fixing an issue with ZONEMD
                         * which hashes the TTL too.
                         */
                        } else if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_SIG
                               ||  ldns_rr_get_type(rr) == LDNS_RR_TYPE_RRSIG) {
                                if (ldns_rr_rd_count(rr) >= 4
                                &&  ldns_rdf_get_type(ldns_rr_rdf(rr, 3)) == LDNS_RDF_TYPE_INT32)
 
                                        /* SIG without explicit ttl get ttl
                                         * from the original_ttl field
                                         * (RFC 2535 Section 7.2)
                                         *
                                         * Similarly for RRSIG, but stated less
                                         * specifically in the spec.
                                         * (RFC 4034 Section 3)
                                         */
                                        ldns_rr_set_ttl(rr,
                                            ldns_rdf2native_int32(
                                                ldns_rr_rdf(rr, 3)));
 
                        } else if (prev_rr
                               &&  ldns_rr_get_type(prev_rr) == ldns_rr_get_type(rr)
                               &&  ldns_dname_compare( ldns_rr_owner(prev_rr)
                                                     , ldns_rr_owner(rr)) == 0)
 
                                /* "TTLs of all RRs in an RRSet must be the same"
                                 * (RFC 2881 Section 5.2)
                                 */
                                ldns_rr_set_ttl(rr, ldns_rr_ttl(prev_rr));
 
                        prev_rr = rr;
                        if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_SOA) {
                                if (soa_seen) {
                                        /* second SOA 
                                         * just skip, maybe we want to say
                                         * something??? */
                                        ldns_rr_free(rr);
                                        continue;
                                }
                                soa_seen = true;
                                ldns_zone_set_soa(newzone, rr);
                                /* set origin to soa if not specified */
                                if (!my_origin) {
                                        my_origin = ldns_rdf_clone(ldns_rr_owner(rr));
                                }
                                continue;
                        }
                        
                        /* a normal RR - as sofar the DNS is normal */
                        if (!ldns_zone_push_rr(newzone, rr)) {
                                ldns_rr_free(rr);
                                goto error;
                        }
                        break;
 
                case LDNS_STATUS_SYNTAX_EMPTY:
                        /* empty line was seen */
                case LDNS_STATUS_SYNTAX_TTL:
                        /* the function set the ttl */
                        default_ttl = my_ttl;
                        ttl_from_TTL = true;
                        break;
                case LDNS_STATUS_SYNTAX_ORIGIN:
                        /* the function set the origin */
                        break;
                case LDNS_STATUS_SYNTAX_INCLUDE:
                        ret = LDNS_STATUS_SYNTAX_INCLUDE_ERR_NOTIMPL;
                        goto error;
                default:
                        ret = s;
                        goto error;
                }
        }
 
        if (my_origin) {
                ldns_rdf_deep_free(my_origin);
        }
        if (my_prev) {
                ldns_rdf_deep_free(my_prev);
        }
        if (z) {
                *z = newzone;
        } else {
                ldns_zone_free(newzone);
        }
 
        return LDNS_STATUS_OK;
 
error:
        if (my_origin) {
                ldns_rdf_deep_free(my_origin);
        }
        if (my_prev) {
                ldns_rdf_deep_free(my_prev);
        }
        if (newzone) {
                ldns_zone_free(newzone);
        }
        return ret;
}
 
void
ldns_zone_sort(ldns_zone *zone)
{
        ldns_rr_list *zrr;
        assert(zone != NULL);
 
        zrr = ldns_zone_rrs(zone);
        ldns_rr_list_sort(zrr);
}
 
void
ldns_zone_free(ldns_zone *zone) 
{
        ldns_rr_list_free(zone->_rrs);
        LDNS_FREE(zone);
}
 
void
ldns_zone_deep_free(ldns_zone *zone) 
{
        ldns_rr_free(zone->_soa);
        ldns_rr_list_deep_free(zone->_rrs);
        LDNS_FREE(zone);
}