packet.c

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/*
 * packet.c
 *
 * dns packet implementation
 *
 * a Net::DNS like library for C
 *
 * (c) NLnet Labs, 2004-2006
 *
 * See the file LICENSE for the license
 */
 
#include <ldns/config.h>
 
#include <ldns/ldns.h>
 
#include <strings.h>
#include <limits.h>
 
#ifdef HAVE_SSL
#include <openssl/rand.h>
#endif
 
/* Access functions 
 * do this as functions to get type checking
 */
 
#define LDNS_EDNS_MASK_DO_BIT 0x8000
#define LDNS_EDNS_MASK_UNASSIGNED (0xFFFF & ~LDNS_EDNS_MASK_DO_BIT)
 
/* TODO defines for 3600 */
/* convert to and from numerical flag values */
ldns_lookup_table ldns_edns_flags[] = {
        { 3600, "do"},
        { 0, NULL}
};
 
/* read */
uint16_t
ldns_pkt_id(const ldns_pkt *packet)
{
        return packet->_header->_id;
}
 
bool
ldns_pkt_qr(const ldns_pkt *packet)
{
        return packet->_header->_qr;
}
 
bool
ldns_pkt_aa(const ldns_pkt *packet)
{
        return packet->_header->_aa;
}
 
bool
ldns_pkt_tc(const ldns_pkt *packet)
{
        return packet->_header->_tc;
}
 
bool
ldns_pkt_rd(const ldns_pkt *packet)
{
        return packet->_header->_rd;
}
 
bool
ldns_pkt_cd(const ldns_pkt *packet)
{
        return packet->_header->_cd;
}
 
bool
ldns_pkt_ra(const ldns_pkt *packet)
{
        return packet->_header->_ra;
}
 
bool
ldns_pkt_ad(const ldns_pkt *packet)
{
        return packet->_header->_ad;
}
 
ldns_pkt_opcode
ldns_pkt_get_opcode(const ldns_pkt *packet)
{
        return packet->_header->_opcode;
}
 
ldns_pkt_rcode
ldns_pkt_get_rcode(const ldns_pkt *packet)
{
        return packet->_header->_rcode;
}
 
uint16_t
ldns_pkt_qdcount(const ldns_pkt *packet)
{
        return packet->_header->_qdcount;
}
 
uint16_t
ldns_pkt_ancount(const ldns_pkt *packet)
{
        return packet->_header->_ancount;
}
 
uint16_t
ldns_pkt_nscount(const ldns_pkt *packet)
{
        return packet->_header->_nscount;
}
 
uint16_t
ldns_pkt_arcount(const ldns_pkt *packet)
{
        return packet->_header->_arcount;
}
 
ldns_rr_list *
ldns_pkt_question(const ldns_pkt *packet)
{
        return packet->_question;
}
 
ldns_rr_list *
ldns_pkt_answer(const ldns_pkt *packet)
{
        return packet->_answer;
}
 
ldns_rr_list *
ldns_pkt_authority(const ldns_pkt *packet)
{
        return packet->_authority;
}
 
ldns_rr_list *
ldns_pkt_additional(const ldns_pkt *packet)
{
        return packet->_additional;
}
 
/* return ALL section concatenated */
ldns_rr_list *
ldns_pkt_all(const ldns_pkt *packet)
{
        ldns_rr_list *all, *prev_all;
 
        all = ldns_rr_list_cat_clone(
                        ldns_pkt_question(packet),
                        ldns_pkt_answer(packet));
        prev_all = all;
        all = ldns_rr_list_cat_clone(all,
                        ldns_pkt_authority(packet));
        ldns_rr_list_deep_free(prev_all);
        prev_all = all;
        all = ldns_rr_list_cat_clone(all,
                        ldns_pkt_additional(packet));
        ldns_rr_list_deep_free(prev_all);
        return all;
}
 
ldns_rr_list *
ldns_pkt_all_noquestion(const ldns_pkt *packet)
{
        ldns_rr_list *all, *all2;
 
        all = ldns_rr_list_cat_clone(
                        ldns_pkt_answer(packet),
                        ldns_pkt_authority(packet));
        all2 = ldns_rr_list_cat_clone(all,
                        ldns_pkt_additional(packet));
        
        ldns_rr_list_deep_free(all);
        return all2;
}
 
size_t
ldns_pkt_size(const ldns_pkt *packet)
{
        return packet->_size;
}
 
uint32_t 
ldns_pkt_querytime(const ldns_pkt *packet)
{
        return packet->_querytime;
}
 
ldns_rdf *
ldns_pkt_answerfrom(const ldns_pkt *packet)
{
        return packet->_answerfrom;
}
 
struct timeval
ldns_pkt_timestamp(const ldns_pkt *packet)
{
        return packet->timestamp;
}
 
uint16_t
ldns_pkt_edns_udp_size(const ldns_pkt *packet)
{
        return packet->_edns_udp_size;
}
 
uint8_t
ldns_pkt_edns_extended_rcode(const ldns_pkt *packet)
{
        return packet->_edns_extended_rcode;
}
 
uint8_t
ldns_pkt_edns_version(const ldns_pkt *packet)
{
        return packet->_edns_version;
}
 
uint16_t
ldns_pkt_edns_z(const ldns_pkt *packet)
{
        return packet->_edns_z;
}
 
bool
ldns_pkt_edns_do(const ldns_pkt *packet)
{
        return (packet->_edns_z & LDNS_EDNS_MASK_DO_BIT);
}
 
void
ldns_pkt_set_edns_do(ldns_pkt *packet, bool value)
{
        if (value) {
                packet->_edns_z = packet->_edns_z | LDNS_EDNS_MASK_DO_BIT;
        } else {
                packet->_edns_z = packet->_edns_z & ~LDNS_EDNS_MASK_DO_BIT;
        }
}
 
uint16_t
ldns_pkt_edns_unassigned(const ldns_pkt *packet)
{
        return (packet->_edns_z & LDNS_EDNS_MASK_UNASSIGNED);
}
 
void
ldns_pkt_set_edns_unassigned(ldns_pkt *packet, uint16_t value)
{
        packet->_edns_z = (packet->_edns_z & ~LDNS_EDNS_MASK_UNASSIGNED)
                        | (value & LDNS_EDNS_MASK_UNASSIGNED);
}
 
ldns_rdf *
ldns_pkt_edns_data(const ldns_pkt *packet)
{
        return packet->_edns_data;
}
 
/* return only those rr that share the ownername */
ldns_rr_list *
ldns_pkt_rr_list_by_name(const ldns_pkt *packet,
                         const ldns_rdf *ownername,
                         ldns_pkt_section sec)
{
        ldns_rr_list *rrs;
        ldns_rr_list *ret;
        uint16_t i;
 
        if (!packet) {
                return NULL;
        }
 
        rrs = ldns_pkt_get_section_clone(packet, sec);
        ret = NULL;
 
        for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
                if (ldns_dname_compare(ldns_rr_owner(
                                                ldns_rr_list_rr(rrs, i)), 
                                        ownername) == 0) {
                        /* owner names match */
                        if (ret == NULL) {
                                ret = ldns_rr_list_new();
                        }
                        ldns_rr_list_push_rr(ret,
                                             ldns_rr_clone(
                                                ldns_rr_list_rr(rrs, i))
                                            );
                }
        }
 
        ldns_rr_list_deep_free(rrs);
 
        return ret;
}
 
/* return only those rr that share a type */
ldns_rr_list *
ldns_pkt_rr_list_by_type(const ldns_pkt *packet,
                         ldns_rr_type type,
                         ldns_pkt_section sec)
{
        ldns_rr_list *rrs;
        ldns_rr_list *new;
        uint16_t i;
 
        if(!packet) {
                return NULL;
        }
        
        rrs = ldns_pkt_get_section_clone(packet, sec);
        new = ldns_rr_list_new();
        
        for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
                if (type == ldns_rr_get_type(ldns_rr_list_rr(rrs, i))) {
                        /* types match */
                        ldns_rr_list_push_rr(new, 
                                             ldns_rr_clone(
                                                ldns_rr_list_rr(rrs, i))
                                             );
                }
        }
        ldns_rr_list_deep_free(rrs);
 
        if (ldns_rr_list_rr_count(new) == 0) {
                ldns_rr_list_free(new);
                return NULL;
        } else {
                return new;
        }
}
 
/* return only those rrs that share name and type */
ldns_rr_list *
ldns_pkt_rr_list_by_name_and_type(const ldns_pkt *packet,
                                  const ldns_rdf *ownername,
                                  ldns_rr_type type,
                                  ldns_pkt_section sec)
{
        ldns_rr_list *rrs;
        ldns_rr_list *new;
        ldns_rr_list *ret;
        uint16_t i;
 
        if(!packet) {
                return NULL;
        }
        
        rrs = ldns_pkt_get_section_clone(packet, sec);
        new = ldns_rr_list_new();
        ret = NULL;
 
        for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
                if (type == ldns_rr_get_type(ldns_rr_list_rr(rrs, i)) &&
                    ldns_dname_compare(ldns_rr_owner(ldns_rr_list_rr(rrs, i)),
                                     ownername
                                    ) == 0
                   ) {
                        /* types match */
                        ldns_rr_list_push_rr(new, ldns_rr_clone(ldns_rr_list_rr(rrs, i)));
                        ret = new;
                }
        }
        ldns_rr_list_deep_free(rrs);
        if (!ret) {
                ldns_rr_list_free(new);
        }
        return ret;
}
 
bool
ldns_pkt_rr(const ldns_pkt *pkt, ldns_pkt_section sec, const ldns_rr *rr)
{
        bool result = false;
 
        switch (sec) {
        case LDNS_SECTION_QUESTION:
                return ldns_rr_list_contains_rr(ldns_pkt_question(pkt), rr);
        case LDNS_SECTION_ANSWER:
                return ldns_rr_list_contains_rr(ldns_pkt_answer(pkt), rr);
        case LDNS_SECTION_AUTHORITY:
                return ldns_rr_list_contains_rr(ldns_pkt_authority(pkt), rr);
        case LDNS_SECTION_ADDITIONAL:
                return ldns_rr_list_contains_rr(ldns_pkt_additional(pkt), rr);
        case LDNS_SECTION_ANY:
                result = ldns_rr_list_contains_rr(ldns_pkt_question(pkt), rr);
                /* fallthrough */
        case LDNS_SECTION_ANY_NOQUESTION:
                result = result
                    || ldns_rr_list_contains_rr(ldns_pkt_answer(pkt), rr)
                    || ldns_rr_list_contains_rr(ldns_pkt_authority(pkt), rr)
                    || ldns_rr_list_contains_rr(ldns_pkt_additional(pkt), rr);
        }
 
        return result;
}
 
uint16_t
ldns_pkt_section_count(const ldns_pkt *packet, ldns_pkt_section s)
{
        switch(s) {
        case LDNS_SECTION_QUESTION:
                return ldns_pkt_qdcount(packet);
        case LDNS_SECTION_ANSWER:
                return ldns_pkt_ancount(packet);
        case LDNS_SECTION_AUTHORITY:
                return ldns_pkt_nscount(packet);
        case LDNS_SECTION_ADDITIONAL:
                return ldns_pkt_arcount(packet);
        case LDNS_SECTION_ANY:
                return ldns_pkt_qdcount(packet) +
                        ldns_pkt_ancount(packet) +
                        ldns_pkt_nscount(packet) +
                        ldns_pkt_arcount(packet);
        case LDNS_SECTION_ANY_NOQUESTION:
                return ldns_pkt_ancount(packet) +
                        ldns_pkt_nscount(packet) +
                        ldns_pkt_arcount(packet);
        default:
                return 0;
        }
}
 
bool
ldns_pkt_empty(ldns_pkt *p)
{
        if (!p) {
                return true; /* NULL is empty? */
        }
        if (ldns_pkt_section_count(p, LDNS_SECTION_ANY) > 0) {
                return false;
        } else {
                return true;
    }
}
 
 
ldns_rr_list *
ldns_pkt_get_section_clone(const ldns_pkt *packet, ldns_pkt_section s)
{
        switch(s) {
        case LDNS_SECTION_QUESTION:
                return ldns_rr_list_clone(ldns_pkt_question(packet));
        case LDNS_SECTION_ANSWER:
                return ldns_rr_list_clone(ldns_pkt_answer(packet));
        case LDNS_SECTION_AUTHORITY:
                return ldns_rr_list_clone(ldns_pkt_authority(packet));
        case LDNS_SECTION_ADDITIONAL:
                return ldns_rr_list_clone(ldns_pkt_additional(packet));
        case LDNS_SECTION_ANY:
                /* these are already clones */
                return ldns_pkt_all(packet);
        case LDNS_SECTION_ANY_NOQUESTION:
                return ldns_pkt_all_noquestion(packet);
        default:
                return NULL;
        }
}
 
ldns_rr *ldns_pkt_tsig(const ldns_pkt *pkt) {
        return pkt->_tsig_rr;
}
 
/* write */
void
ldns_pkt_set_id(ldns_pkt *packet, uint16_t id)
{
        packet->_header->_id = id;
}
 
void
ldns_pkt_set_random_id(ldns_pkt *packet)
{
        uint16_t rid = ldns_get_random();
        ldns_pkt_set_id(packet, rid);
}
 
 
void
ldns_pkt_set_qr(ldns_pkt *packet, bool qr)
{
        packet->_header->_qr = qr;
}
 
void
ldns_pkt_set_aa(ldns_pkt *packet, bool aa)
{
        packet->_header->_aa = aa;
}
 
void
ldns_pkt_set_tc(ldns_pkt *packet, bool tc)
{
        packet->_header->_tc = tc;
}
 
void
ldns_pkt_set_rd(ldns_pkt *packet, bool rd)
{
        packet->_header->_rd = rd;
}
 
void
ldns_pkt_set_additional(ldns_pkt *p, ldns_rr_list *rr)
{
        p->_additional = rr;
}
 
void
ldns_pkt_set_question(ldns_pkt *p, ldns_rr_list *rr)
{
        p->_question = rr;
}
 
void
ldns_pkt_set_answer(ldns_pkt *p, ldns_rr_list *rr)
{
        p->_answer = rr;
}
 
void
ldns_pkt_set_authority(ldns_pkt *p, ldns_rr_list *rr)
{
        p->_authority = rr;
}
 
void
ldns_pkt_set_cd(ldns_pkt *packet, bool cd)
{
        packet->_header->_cd = cd;
}
 
void
ldns_pkt_set_ra(ldns_pkt *packet, bool ra)
{
        packet->_header->_ra = ra;
}
 
void
ldns_pkt_set_ad(ldns_pkt *packet, bool ad)
{
        packet->_header->_ad = ad;
}
 
void
ldns_pkt_set_opcode(ldns_pkt *packet, ldns_pkt_opcode opcode)
{
        packet->_header->_opcode = opcode;
}
 
void
ldns_pkt_set_rcode(ldns_pkt *packet, uint8_t rcode)
{
        packet->_header->_rcode = rcode;
}
 
void
ldns_pkt_set_qdcount(ldns_pkt *packet, uint16_t qdcount)
{
        packet->_header->_qdcount = qdcount;
}
 
void
ldns_pkt_set_ancount(ldns_pkt *packet, uint16_t ancount)
{
        packet->_header->_ancount = ancount;
}
 
void
ldns_pkt_set_nscount(ldns_pkt *packet, uint16_t nscount)
{
        packet->_header->_nscount = nscount;
}
 
void
ldns_pkt_set_arcount(ldns_pkt *packet, uint16_t arcount)
{
        packet->_header->_arcount = arcount;
}
 
void
ldns_pkt_set_querytime(ldns_pkt *packet, uint32_t time) 
{
        packet->_querytime = time;
}
 
void
ldns_pkt_set_answerfrom(ldns_pkt *packet, ldns_rdf *answerfrom)
{
        packet->_answerfrom = answerfrom;
}
 
void
ldns_pkt_set_timestamp(ldns_pkt *packet, struct timeval timeval)
{
        packet->timestamp.tv_sec = timeval.tv_sec;
        packet->timestamp.tv_usec = timeval.tv_usec;
}
 
void
ldns_pkt_set_size(ldns_pkt *packet, size_t s)
{
        packet->_size = s;
}
 
void
ldns_pkt_set_edns_udp_size(ldns_pkt *packet, uint16_t s)
{
        packet->_edns_udp_size = s;
}
 
void
ldns_pkt_set_edns_extended_rcode(ldns_pkt *packet, uint8_t c)
{
        packet->_edns_extended_rcode = c;
}
 
void
ldns_pkt_set_edns_version(ldns_pkt *packet, uint8_t v)
{
        packet->_edns_version = v;
}
 
void
ldns_pkt_set_edns_z(ldns_pkt *packet, uint16_t z)
{
        packet->_edns_z = z;
}
 
void
ldns_pkt_set_edns_data(ldns_pkt *packet, ldns_rdf *data)
{
        packet->_edns_data = data;
}
 
void
ldns_pkt_set_edns_option_list(ldns_pkt *packet, ldns_edns_option_list *list)
{
        if (packet->_edns_list)
                ldns_edns_option_list_deep_free(packet->_edns_list);
        packet->_edns_list = list;
}
 
 
void
ldns_pkt_set_section_count(ldns_pkt *packet, ldns_pkt_section s, uint16_t count)
{
        switch(s) {
                case LDNS_SECTION_QUESTION:
                        ldns_pkt_set_qdcount(packet, count);
                        break;
                case LDNS_SECTION_ANSWER:
                        ldns_pkt_set_ancount(packet, count);
                        break;
                case LDNS_SECTION_AUTHORITY:
                        ldns_pkt_set_nscount(packet, count);
                        break;
                case LDNS_SECTION_ADDITIONAL:
                        ldns_pkt_set_arcount(packet, count);
                        break;
                case LDNS_SECTION_ANY:
                case LDNS_SECTION_ANY_NOQUESTION:
                        break;
        }
}
 
void ldns_pkt_set_tsig(ldns_pkt *pkt, ldns_rr *rr)
{
        pkt->_tsig_rr = rr;
}
 
bool
ldns_pkt_push_rr(ldns_pkt *packet, ldns_pkt_section section, ldns_rr *rr)
{
        switch(section) {
                case LDNS_SECTION_QUESTION:
                        if (!ldns_rr_list_push_rr(ldns_pkt_question(packet), rr)) {
                                return false;
                        }
                        ldns_pkt_set_qdcount(packet, ldns_pkt_qdcount(packet) + 1);
                        break;
                case LDNS_SECTION_ANSWER:
                        if (!ldns_rr_list_push_rr(ldns_pkt_answer(packet), rr)) {
                                return false;
                        }
                        ldns_pkt_set_ancount(packet, ldns_pkt_ancount(packet) + 1);
                        break;
                case LDNS_SECTION_AUTHORITY:
                        if (!ldns_rr_list_push_rr(ldns_pkt_authority(packet), rr)) {
                                return false;
                        }
                        ldns_pkt_set_nscount(packet, ldns_pkt_nscount(packet) + 1);
                        break;
                case LDNS_SECTION_ADDITIONAL:
                        if (!ldns_rr_list_push_rr(ldns_pkt_additional(packet), rr)) {
                                return false;
                        }
                        ldns_pkt_set_arcount(packet, ldns_pkt_arcount(packet) + 1);
                        break;
                case LDNS_SECTION_ANY:
                case LDNS_SECTION_ANY_NOQUESTION:
                        /* shouldn't this error? */
                        break;
        }
        return true;
}
 
bool
ldns_pkt_safe_push_rr(ldns_pkt *pkt, ldns_pkt_section sec, ldns_rr *rr)
{
 
        /* check to see if its there */
        if (ldns_pkt_rr(pkt, sec, rr)) {
                /* already there */
                return false;
        }
        return ldns_pkt_push_rr(pkt, sec, rr);
}
 
bool
ldns_pkt_push_rr_list(ldns_pkt *p, ldns_pkt_section s, ldns_rr_list *list)
{
        size_t i;
        for(i = 0; i < ldns_rr_list_rr_count(list); i++) {
                if (!ldns_pkt_push_rr(p, s, ldns_rr_list_rr(list, i))) {
                        return false;
                }
        }
        return true;
}
 
bool
ldns_pkt_safe_push_rr_list(ldns_pkt *p, ldns_pkt_section s, ldns_rr_list *list)
{
        size_t i;
        for(i = 0; i < ldns_rr_list_rr_count(list); i++) {
                if (!ldns_pkt_safe_push_rr(p, s, ldns_rr_list_rr(list, i))) {
                        return false;
                }
        }
        return true;
}
 
bool
ldns_pkt_edns(const ldns_pkt *pkt)
{
        return (ldns_pkt_edns_udp_size(pkt) > 0 ||
                ldns_pkt_edns_extended_rcode(pkt) > 0 ||
                ldns_pkt_edns_data(pkt) ||
                ldns_pkt_edns_do(pkt) ||
                pkt->_edns_list ||
                pkt->_edns_present
               );
}
 
ldns_edns_option_list*
pkt_edns_data2edns_option_list(const ldns_rdf *edns_data);
ldns_edns_option_list*
pkt_edns_data2edns_option_list(const ldns_rdf *edns_data)
{
        size_t pos = 0;
        ldns_edns_option_list* edns_list;
        size_t max;
        const uint8_t* wire;
 
        if (!edns_data)
                return NULL;
 
        max = ldns_rdf_size(edns_data);
        wire = ldns_rdf_data(edns_data);
        if (!max)
                return NULL;
 
        if (!(edns_list = ldns_edns_option_list_new()))
                return NULL;
 
        while (pos < max) {
                ldns_edns_option* edns;
                uint8_t *data;
 
                if (pos + 4 > max) { /* make sure the header fits */
                        ldns_edns_option_list_deep_free(edns_list);
                        return NULL;
                }
                ldns_edns_option_code code = ldns_read_uint16(&wire[pos]);
                size_t size = ldns_read_uint16(&wire[pos+2]);
                pos += 4;
 
                if (pos + size > max) { /* make sure the size fits the data */
                        ldns_edns_option_list_deep_free(edns_list);
                        return NULL;
                }
                data = LDNS_XMALLOC(uint8_t, size);
 
                if (!data) {
                        ldns_edns_option_list_deep_free(edns_list);
                        return NULL;
                }
                memcpy(data, &wire[pos], size);
                pos += size;
 
                edns = ldns_edns_new(code, size, data);
 
                if (!edns) {
                        ldns_edns_option_list_deep_free(edns_list);
                        return NULL;
                }
                if (!ldns_edns_option_list_push(edns_list, edns)) {
                        ldns_edns_option_list_deep_free(edns_list);
                        return NULL;
                }
        }
        return edns_list;
 
}
 
ldns_edns_option_list*
ldns_pkt_edns_get_option_list(ldns_pkt *packet)
{
        /* return the list if it already exists */
        if (packet->_edns_list != NULL)
                return packet->_edns_list;
 
        /* if the list doesn't exists, we create it by parsing the
         * packet->_edns_data
         */
        if (!ldns_pkt_edns_data(packet))
                return NULL;
 
        return ( packet->_edns_list
               = pkt_edns_data2edns_option_list(ldns_pkt_edns_data(packet)));
}
 
 
/* Create/destroy/convert functions
 */
ldns_pkt *
ldns_pkt_new(void)
{
        ldns_pkt *packet;
        packet = LDNS_MALLOC(ldns_pkt);
        if (!packet) {
                return NULL;
        }
 
        packet->_header = LDNS_MALLOC(ldns_hdr);
        if (!packet->_header) {
                LDNS_FREE(packet);
                return NULL;
        }
 
        packet->_question = ldns_rr_list_new();
        packet->_answer = ldns_rr_list_new();
        packet->_authority = ldns_rr_list_new();
        packet->_additional = ldns_rr_list_new();
 
        /* default everything to false */
        ldns_pkt_set_qr(packet, false);
        ldns_pkt_set_aa(packet, false);
        ldns_pkt_set_tc(packet, false);
        ldns_pkt_set_rd(packet, false);
        ldns_pkt_set_ra(packet, false);
        ldns_pkt_set_ad(packet, false);
        ldns_pkt_set_cd(packet, false);
 
        ldns_pkt_set_opcode(packet, LDNS_PACKET_QUERY);
        ldns_pkt_set_rcode(packet, 0);
        ldns_pkt_set_id(packet, 0); 
        ldns_pkt_set_size(packet, 0);
        ldns_pkt_set_querytime(packet, 0);
        memset(&packet->timestamp, 0, sizeof(packet->timestamp));
        ldns_pkt_set_answerfrom(packet, NULL);
        ldns_pkt_set_section_count(packet, LDNS_SECTION_QUESTION, 0);
        ldns_pkt_set_section_count(packet, LDNS_SECTION_ANSWER, 0);
        ldns_pkt_set_section_count(packet, LDNS_SECTION_AUTHORITY, 0);
        ldns_pkt_set_section_count(packet, LDNS_SECTION_ADDITIONAL, 0);
        
        ldns_pkt_set_edns_udp_size(packet, 0);
        ldns_pkt_set_edns_extended_rcode(packet, 0);
        ldns_pkt_set_edns_version(packet, 0);
        ldns_pkt_set_edns_z(packet, 0);
        ldns_pkt_set_edns_data(packet, NULL);
        packet->_edns_list = NULL;
        packet->_edns_present = false;
 
        ldns_pkt_set_tsig(packet, NULL);
        
        return packet;
}
 
void
ldns_pkt_free(ldns_pkt *packet)
{
        if (packet) {
                LDNS_FREE(packet->_header);
                ldns_rr_list_deep_free(packet->_question);
                ldns_rr_list_deep_free(packet->_answer);
                ldns_rr_list_deep_free(packet->_authority);
                ldns_rr_list_deep_free(packet->_additional);
                ldns_rr_free(packet->_tsig_rr);
                ldns_rdf_deep_free(packet->_edns_data);
                ldns_edns_option_list_deep_free(packet->_edns_list);
                ldns_rdf_deep_free(packet->_answerfrom);
                LDNS_FREE(packet);
        }
}
 
bool
ldns_pkt_set_flags(ldns_pkt *packet, uint16_t flags)
{
        if (!packet) {
                return false;
        }
        if ((flags & LDNS_QR) == LDNS_QR) {
                ldns_pkt_set_qr(packet, true);
        }
        if ((flags & LDNS_AA) == LDNS_AA) {
                ldns_pkt_set_aa(packet, true);
        }
        if ((flags & LDNS_RD) == LDNS_RD) {
                ldns_pkt_set_rd(packet, true);
        }
        if ((flags & LDNS_TC) == LDNS_TC) {
                ldns_pkt_set_tc(packet, true);
        }
        if ((flags & LDNS_CD) == LDNS_CD) {
                ldns_pkt_set_cd(packet, true);
        }
        if ((flags & LDNS_RA) == LDNS_RA) {
                ldns_pkt_set_ra(packet, true);
        }
        if ((flags & LDNS_AD) == LDNS_AD) {
                ldns_pkt_set_ad(packet, true);
        }
        return true;
}
 
 
static ldns_rr*
ldns_pkt_authsoa(const ldns_rdf* rr_name, ldns_rr_class rr_class)
{
        ldns_rr* soa_rr = ldns_rr_new();
        ldns_rdf *owner_rdf;
        ldns_rdf *mname_rdf;
        ldns_rdf *rname_rdf;
        ldns_rdf *serial_rdf;
        ldns_rdf *refresh_rdf;
        ldns_rdf *retry_rdf;
        ldns_rdf *expire_rdf;
        ldns_rdf *minimum_rdf;
 
        if (!soa_rr) {
                return NULL;
        }
        owner_rdf = ldns_rdf_clone(rr_name);
        if (!owner_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        }
 
        ldns_rr_set_owner(soa_rr, owner_rdf);
        ldns_rr_set_type(soa_rr, LDNS_RR_TYPE_SOA);
        ldns_rr_set_class(soa_rr, rr_class);
        ldns_rr_set_question(soa_rr, false);
 
        if (ldns_str2rdf_dname(&mname_rdf, ".") != LDNS_STATUS_OK) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, mname_rdf);
        }
        if (ldns_str2rdf_dname(&rname_rdf, ".") != LDNS_STATUS_OK) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, rname_rdf);
        }
        serial_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
        if (!serial_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, serial_rdf);
        }
        refresh_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
        if (!refresh_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, refresh_rdf);
        }
        retry_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
        if (!retry_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, retry_rdf);
        }
        expire_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
        if (!expire_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, expire_rdf);
        }
        minimum_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
        if (!minimum_rdf) {
                ldns_rr_free(soa_rr);
                return NULL;
        } else {
                ldns_rr_push_rdf(soa_rr, minimum_rdf);
        }
        return soa_rr;
}
 
 
static ldns_status
ldns_pkt_query_new_frm_str_internal(ldns_pkt **p, const char *name,
        ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags,
        ldns_rr* authsoa_rr)
{
        ldns_pkt *packet;
        ldns_rr *question_rr;
        ldns_rdf *name_rdf;
 
        packet = ldns_pkt_new();
        if (!packet) {
                return LDNS_STATUS_MEM_ERR;
        }
 
        if (!ldns_pkt_set_flags(packet, flags)) {
                ldns_pkt_free(packet);
                return LDNS_STATUS_ERR;
        }
 
        question_rr = ldns_rr_new();
        if (!question_rr) {
                ldns_pkt_free(packet);
                return LDNS_STATUS_MEM_ERR;
        }
 
        if (rr_type == 0) {
                rr_type = LDNS_RR_TYPE_A;
        }
        if (rr_class == 0) {
                rr_class = LDNS_RR_CLASS_IN;
        }
 
        if (ldns_str2rdf_dname(&name_rdf, name) == LDNS_STATUS_OK) {
                ldns_rr_set_owner(question_rr, name_rdf);
                ldns_rr_set_type(question_rr, rr_type);
                ldns_rr_set_class(question_rr, rr_class);
                ldns_rr_set_question(question_rr, true);
 
                ldns_pkt_push_rr(packet, LDNS_SECTION_QUESTION, question_rr);
        } else {
                ldns_rr_free(question_rr);
                ldns_pkt_free(packet);
                return LDNS_STATUS_ERR;
        }
 
        if (authsoa_rr) {
                ldns_pkt_push_rr(packet, LDNS_SECTION_AUTHORITY, authsoa_rr);
        }
 
        packet->_tsig_rr = NULL;
        ldns_pkt_set_answerfrom(packet, NULL);
        if (p) {
                *p = packet;
                return LDNS_STATUS_OK;
        } else {
                ldns_pkt_free(packet);
                return LDNS_STATUS_NULL;
        }
}
 
ldns_status
ldns_pkt_query_new_frm_str(ldns_pkt **p, const char *name,
        ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags)
{
        return ldns_pkt_query_new_frm_str_internal(p, name, rr_type,
                rr_class, flags, NULL);
}
 
ldns_status
ldns_pkt_ixfr_request_new_frm_str(ldns_pkt **p, const char *name,
        ldns_rr_class rr_class, uint16_t flags, ldns_rr *soa)
{
        ldns_rr* authsoa_rr = soa;
        if (!authsoa_rr) {
                ldns_rdf *name_rdf;
                if (ldns_str2rdf_dname(&name_rdf, name) == LDNS_STATUS_OK) {
                        authsoa_rr = ldns_pkt_authsoa(name_rdf, rr_class);
                }
                ldns_rdf_free(name_rdf);
        }
        return ldns_pkt_query_new_frm_str_internal(p, name, LDNS_RR_TYPE_IXFR,
                rr_class, flags, authsoa_rr);
}
 
static ldns_pkt *
ldns_pkt_query_new_internal(ldns_rdf *rr_name, ldns_rr_type rr_type,
        ldns_rr_class rr_class, uint16_t flags, ldns_rr* authsoa_rr)
{
        ldns_pkt *packet;
        ldns_rr *question_rr;
 
        packet = ldns_pkt_new();
        if (!packet) {
                return NULL;
        }
 
        if (!ldns_pkt_set_flags(packet, flags)) {
                return NULL;
        }
 
        question_rr = ldns_rr_new();
        if (!question_rr) {
                ldns_pkt_free(packet);
                return NULL;
        }
 
        if (rr_type == 0) {
                rr_type = LDNS_RR_TYPE_A;
        }
        if (rr_class == 0) {
                rr_class = LDNS_RR_CLASS_IN;
        }
 
        ldns_rr_set_owner(question_rr, rr_name);
        ldns_rr_set_type(question_rr, rr_type);
        ldns_rr_set_class(question_rr, rr_class);
        ldns_rr_set_question(question_rr, true);
        ldns_pkt_push_rr(packet, LDNS_SECTION_QUESTION, question_rr);
 
        if (authsoa_rr) {
                ldns_pkt_push_rr(packet, LDNS_SECTION_AUTHORITY, authsoa_rr);
        }
 
        packet->_tsig_rr = NULL;
        return packet;
}
 
ldns_pkt *
ldns_pkt_query_new(ldns_rdf *rr_name, ldns_rr_type rr_type,
        ldns_rr_class rr_class, uint16_t flags)
{
        return ldns_pkt_query_new_internal(rr_name, rr_type,
                rr_class, flags, NULL);
}
 
ldns_pkt *
ldns_pkt_ixfr_request_new(ldns_rdf *rr_name, ldns_rr_class rr_class,
        uint16_t flags, ldns_rr* soa)
{
        ldns_rr* authsoa_rr = soa;
        if (!authsoa_rr) {
                authsoa_rr = ldns_pkt_authsoa(rr_name, rr_class);
        }
        return ldns_pkt_query_new_internal(rr_name, LDNS_RR_TYPE_IXFR,
                rr_class, flags, authsoa_rr);
}
 
ldns_pkt_type
ldns_pkt_reply_type(const ldns_pkt *p)
{
        ldns_rr_list *tmp;
 
        if (!p) {
                return LDNS_PACKET_UNKNOWN;
        }
 
        if (ldns_pkt_get_rcode(p) == LDNS_RCODE_NXDOMAIN) {
                return LDNS_PACKET_NXDOMAIN;
        }
 
        if (ldns_pkt_ancount(p) == 0 && ldns_pkt_arcount(p) == 0
                        && ldns_pkt_nscount(p) == 1) {
 
                /* check for SOA */
                tmp = ldns_pkt_rr_list_by_type(p, LDNS_RR_TYPE_SOA, 
                                        LDNS_SECTION_AUTHORITY);
                if (tmp) {
                        ldns_rr_list_deep_free(tmp);
                        return LDNS_PACKET_NODATA;
                } else {
                        /* I have no idea ... */
                }
        }
 
        if (ldns_pkt_ancount(p) == 0 && ldns_pkt_nscount(p) > 0) {
                tmp = ldns_pkt_rr_list_by_type(p, LDNS_RR_TYPE_NS,
                                               LDNS_SECTION_AUTHORITY);
                if (tmp) {
                        /* there are nameservers here */
                        ldns_rr_list_deep_free(tmp);
                        return LDNS_PACKET_REFERRAL;
                } else {
                        /* I have no idea */
                }
                ldns_rr_list_deep_free(tmp);
        }
        
        /* if we cannot determine the packet type, we say it's an 
         * answer...
         */
        return LDNS_PACKET_ANSWER;
}
 
ldns_pkt *
ldns_pkt_clone(const ldns_pkt *pkt)
{
        ldns_pkt *new_pkt;
        
        if (!pkt) {
                return NULL;
        }
        new_pkt = ldns_pkt_new();
 
        ldns_pkt_set_id(new_pkt, ldns_pkt_id(pkt));
        ldns_pkt_set_qr(new_pkt, ldns_pkt_qr(pkt));
        ldns_pkt_set_aa(new_pkt, ldns_pkt_aa(pkt));
        ldns_pkt_set_tc(new_pkt, ldns_pkt_tc(pkt));
        ldns_pkt_set_rd(new_pkt, ldns_pkt_rd(pkt));
        ldns_pkt_set_cd(new_pkt, ldns_pkt_cd(pkt));
        ldns_pkt_set_ra(new_pkt, ldns_pkt_ra(pkt));
        ldns_pkt_set_ad(new_pkt, ldns_pkt_ad(pkt));
        ldns_pkt_set_opcode(new_pkt, ldns_pkt_get_opcode(pkt));
        ldns_pkt_set_rcode(new_pkt, ldns_pkt_get_rcode(pkt));
        ldns_pkt_set_qdcount(new_pkt, ldns_pkt_qdcount(pkt));
        ldns_pkt_set_ancount(new_pkt, ldns_pkt_ancount(pkt));
        ldns_pkt_set_nscount(new_pkt, ldns_pkt_nscount(pkt));
        ldns_pkt_set_arcount(new_pkt, ldns_pkt_arcount(pkt));
        if (ldns_pkt_answerfrom(pkt))
                ldns_pkt_set_answerfrom(new_pkt,
                        ldns_rdf_clone(ldns_pkt_answerfrom(pkt)));
        ldns_pkt_set_timestamp(new_pkt, ldns_pkt_timestamp(pkt));
        ldns_pkt_set_querytime(new_pkt, ldns_pkt_querytime(pkt));
        ldns_pkt_set_size(new_pkt, ldns_pkt_size(pkt));
        ldns_pkt_set_tsig(new_pkt, ldns_rr_clone(ldns_pkt_tsig(pkt)));
        
        ldns_pkt_set_edns_udp_size(new_pkt, ldns_pkt_edns_udp_size(pkt));
        ldns_pkt_set_edns_extended_rcode(new_pkt, 
                ldns_pkt_edns_extended_rcode(pkt));
        ldns_pkt_set_edns_version(new_pkt, ldns_pkt_edns_version(pkt));
        new_pkt->_edns_present = pkt->_edns_present;
        ldns_pkt_set_edns_z(new_pkt, ldns_pkt_edns_z(pkt));
        if(ldns_pkt_edns_data(pkt))
                ldns_pkt_set_edns_data(new_pkt, 
                        ldns_rdf_clone(ldns_pkt_edns_data(pkt)));
        ldns_pkt_set_edns_do(new_pkt, ldns_pkt_edns_do(pkt));
        if (pkt->_edns_list)
                ldns_pkt_set_edns_option_list(new_pkt,
                        ldns_edns_option_list_clone(pkt->_edns_list));
 
        ldns_rr_list_deep_free(new_pkt->_question);
        ldns_rr_list_deep_free(new_pkt->_answer);
        ldns_rr_list_deep_free(new_pkt->_authority);
        ldns_rr_list_deep_free(new_pkt->_additional);
        new_pkt->_question = ldns_rr_list_clone(ldns_pkt_question(pkt));
        new_pkt->_answer = ldns_rr_list_clone(ldns_pkt_answer(pkt));
        new_pkt->_authority = ldns_rr_list_clone(ldns_pkt_authority(pkt));
        new_pkt->_additional = ldns_rr_list_clone(ldns_pkt_additional(pkt));
        return new_pkt;
}