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freebsd-skq/contrib/ldns/wire2host.c
des d300320fbe Upgrade LDNS to 1.7.0. 
I've been holding back on this because 1.7.0 requires OpenSSL 1.1.0 or
newer for full DANE support.  But we can't wait forever, and nothing in
base uses DANE anyway, so here we go.
2018-05-12 12:00:18 +00:00

492 lines
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/*
* wire2host.c
*
* conversion routines from the wire to the host
* format.
* This will usually just a re-ordering of the
* data (as we store it in network format)
*
* 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 <ldns/wire2host.h>*/
#include <strings.h>
#include <limits.h>
/*
* Set of macro's to deal with the dns message header as specified
* in RFC1035 in portable way.
*
*/
/*
*
* 1 1 1 1 1 1
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | ID |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* |QR| Opcode |AA|TC|RD|RA| Z|AD|CD| RCODE |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | QDCOUNT |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | ANCOUNT |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | NSCOUNT |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
* | ARCOUNT |
* +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
*
*/
/* allocates memory to *dname! */
ldns_status
ldns_wire2dname(ldns_rdf **dname, const uint8_t *wire, size_t max, size_t *pos)
{
uint8_t label_size;
uint16_t pointer_target;
uint8_t pointer_target_buf[2];
size_t dname_pos = 0;
size_t uncompressed_length = 0;
size_t compression_pos = 0;
uint8_t tmp_dname[LDNS_MAX_DOMAINLEN];
unsigned int pointer_count = 0;
if (pos == NULL) {
return LDNS_STATUS_WIRE_RDATA_ERR;
}
if (*pos >= max) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
label_size = wire[*pos];
while (label_size > 0) {
/* compression */
while (label_size >= 192) {
if (compression_pos == 0) {
compression_pos = *pos + 2;
}
pointer_count++;
/* remove first two bits */
if (*pos + 2 > max) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
pointer_target_buf[0] = wire[*pos] & 63;
pointer_target_buf[1] = wire[*pos + 1];
pointer_target = ldns_read_uint16(pointer_target_buf);
if (pointer_target == 0) {
return LDNS_STATUS_INVALID_POINTER;
} else if (pointer_target >= max) {
return LDNS_STATUS_INVALID_POINTER;
} else if (pointer_count > LDNS_MAX_POINTERS) {
return LDNS_STATUS_INVALID_POINTER;
}
*pos = pointer_target;
label_size = wire[*pos];
}
if(label_size == 0)
break; /* break from pointer to 0 byte */
if (label_size > LDNS_MAX_LABELLEN) {
return LDNS_STATUS_LABEL_OVERFLOW;
}
if (*pos + 1 + label_size > max) {
return LDNS_STATUS_LABEL_OVERFLOW;
}
/* check space for labelcount itself */
if (dname_pos + 1 > LDNS_MAX_DOMAINLEN) {
return LDNS_STATUS_DOMAINNAME_OVERFLOW;
}
tmp_dname[dname_pos] = label_size;
if (label_size > 0) {
dname_pos++;
}
*pos = *pos + 1;
if (dname_pos + label_size > LDNS_MAX_DOMAINLEN) {
return LDNS_STATUS_DOMAINNAME_OVERFLOW;
}
memcpy(&tmp_dname[dname_pos], &wire[*pos], label_size);
uncompressed_length += label_size + 1;
dname_pos += label_size;
*pos = *pos + label_size;
if (*pos < max) {
label_size = wire[*pos];
}
}
if (compression_pos > 0) {
*pos = compression_pos;
} else {
*pos = *pos + 1;
}
if (dname_pos >= LDNS_MAX_DOMAINLEN) {
return LDNS_STATUS_DOMAINNAME_OVERFLOW;
}
tmp_dname[dname_pos] = 0;
dname_pos++;
*dname = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_DNAME,
(uint16_t) dname_pos, tmp_dname);
if (!*dname) {
return LDNS_STATUS_MEM_ERR;
}
return LDNS_STATUS_OK;
}
/* maybe make this a goto error so data can be freed or something/ */
#define LDNS_STATUS_CHECK_RETURN(st) {if (st != LDNS_STATUS_OK) { return st; }}
#define LDNS_STATUS_CHECK_GOTO(st, label) {if (st != LDNS_STATUS_OK) { /*printf("STG %s:%d: status code %d\n", __FILE__, __LINE__, st);*/ goto label; }}
ldns_status
ldns_wire2rdf(ldns_rr *rr, const uint8_t *wire, size_t max, size_t *pos)
{
size_t end;
size_t cur_rdf_length;
uint8_t rdf_index;
uint8_t *data;
uint16_t rd_length;
ldns_rdf *cur_rdf = NULL;
ldns_rdf_type cur_rdf_type;
const ldns_rr_descriptor *descriptor;
ldns_status status;
assert(rr != NULL);
descriptor = ldns_rr_descript(ldns_rr_get_type(rr));
if (*pos + 2 > max) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
rd_length = ldns_read_uint16(&wire[*pos]);
*pos = *pos + 2;
if (*pos + rd_length > max) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
end = *pos + (size_t) rd_length;
rdf_index = 0;
while (*pos < end &&
rdf_index < ldns_rr_descriptor_maximum(descriptor)) {
cur_rdf_length = 0;
cur_rdf_type = ldns_rr_descriptor_field_type(
descriptor, rdf_index);
/* handle special cases immediately, set length
for fixed length rdata and do them below */
switch (cur_rdf_type) {
case LDNS_RDF_TYPE_DNAME:
status = ldns_wire2dname(&cur_rdf, wire, max, pos);
LDNS_STATUS_CHECK_RETURN(status);
break;
case LDNS_RDF_TYPE_CLASS:
case LDNS_RDF_TYPE_ALG:
case LDNS_RDF_TYPE_CERTIFICATE_USAGE:
case LDNS_RDF_TYPE_SELECTOR:
case LDNS_RDF_TYPE_MATCHING_TYPE:
case LDNS_RDF_TYPE_INT8:
cur_rdf_length = LDNS_RDF_SIZE_BYTE;
break;
case LDNS_RDF_TYPE_TYPE:
case LDNS_RDF_TYPE_INT16:
case LDNS_RDF_TYPE_CERT_ALG:
cur_rdf_length = LDNS_RDF_SIZE_WORD;
break;
case LDNS_RDF_TYPE_TIME:
case LDNS_RDF_TYPE_INT32:
case LDNS_RDF_TYPE_A:
case LDNS_RDF_TYPE_PERIOD:
cur_rdf_length = LDNS_RDF_SIZE_DOUBLEWORD;
break;
case LDNS_RDF_TYPE_TSIGTIME:
case LDNS_RDF_TYPE_EUI48:
cur_rdf_length = LDNS_RDF_SIZE_6BYTES;
break;
case LDNS_RDF_TYPE_ILNP64:
case LDNS_RDF_TYPE_EUI64:
cur_rdf_length = LDNS_RDF_SIZE_8BYTES;
break;
case LDNS_RDF_TYPE_AAAA:
cur_rdf_length = LDNS_RDF_SIZE_16BYTES;
break;
case LDNS_RDF_TYPE_STR:
case LDNS_RDF_TYPE_NSEC3_SALT:
case LDNS_RDF_TYPE_TAG:
/* len is stored in first byte
* it should be in the rdf too, so just
* copy len+1 from this position
*/
cur_rdf_length = ((size_t) wire[*pos]) + 1;
break;
case LDNS_RDF_TYPE_INT16_DATA:
if (*pos + 2 > end) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
cur_rdf_length =
(size_t) ldns_read_uint16(&wire[*pos]) + 2;
break;
case LDNS_RDF_TYPE_HIP:
if (*pos + 4 > end) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
cur_rdf_length =
(size_t) wire[*pos] +
(size_t) ldns_read_uint16(&wire[*pos + 2]) + 4;
break;
case LDNS_RDF_TYPE_B32_EXT:
case LDNS_RDF_TYPE_NSEC3_NEXT_OWNER:
/* length is stored in first byte */
cur_rdf_length = ((size_t) wire[*pos]) + 1;
break;
case LDNS_RDF_TYPE_APL:
case LDNS_RDF_TYPE_B64:
case LDNS_RDF_TYPE_HEX:
case LDNS_RDF_TYPE_NSEC:
case LDNS_RDF_TYPE_UNKNOWN:
case LDNS_RDF_TYPE_SERVICE:
case LDNS_RDF_TYPE_LOC:
case LDNS_RDF_TYPE_WKS:
case LDNS_RDF_TYPE_NSAP:
case LDNS_RDF_TYPE_ATMA:
case LDNS_RDF_TYPE_IPSECKEY:
case LDNS_RDF_TYPE_LONG_STR:
case LDNS_RDF_TYPE_NONE:
/*
* Read to end of rr rdata
*/
cur_rdf_length = end - *pos;
break;
}
/* fixed length rdata */
if (cur_rdf_length > 0) {
if (cur_rdf_length + *pos > end) {
return LDNS_STATUS_PACKET_OVERFLOW;
}
data = LDNS_XMALLOC(uint8_t, rd_length);
if (!data) {
return LDNS_STATUS_MEM_ERR;
}
memcpy(data, &wire[*pos], cur_rdf_length);
cur_rdf = ldns_rdf_new(cur_rdf_type,
cur_rdf_length, data);
*pos = *pos + cur_rdf_length;
}
if (cur_rdf) {
ldns_rr_push_rdf(rr, cur_rdf);
cur_rdf = NULL;
}
rdf_index++;
} /* while (rdf_index < ldns_rr_descriptor_maximum(descriptor)) */
return LDNS_STATUS_OK;
}
/* TODO:
can *pos be incremented at READ_INT? or maybe use something like
RR_CLASS(wire)?
uhhm Jelte??
*/
ldns_status
ldns_wire2rr(ldns_rr **rr_p, const uint8_t *wire, size_t max,
size_t *pos, ldns_pkt_section section)
{
ldns_rdf *owner = NULL;
ldns_rr *rr = ldns_rr_new();
ldns_status status;
status = ldns_wire2dname(&owner, wire, max, pos);
LDNS_STATUS_CHECK_GOTO(status, status_error);
ldns_rr_set_owner(rr, owner);
if (*pos + 4 > max) {
status = LDNS_STATUS_PACKET_OVERFLOW;
goto status_error;
}
ldns_rr_set_type(rr, ldns_read_uint16(&wire[*pos]));
*pos = *pos + 2;
ldns_rr_set_class(rr, ldns_read_uint16(&wire[*pos]));
*pos = *pos + 2;
if (section != LDNS_SECTION_QUESTION) {
if (*pos + 4 > max) {
status = LDNS_STATUS_PACKET_OVERFLOW;
goto status_error;
}
ldns_rr_set_ttl(rr, ldns_read_uint32(&wire[*pos]));
*pos = *pos + 4;
status = ldns_wire2rdf(rr, wire, max, pos);
LDNS_STATUS_CHECK_GOTO(status, status_error);
ldns_rr_set_question(rr, false);
} else {
ldns_rr_set_question(rr, true);
}
*rr_p = rr;
return LDNS_STATUS_OK;
status_error:
ldns_rr_free(rr);
return status;
}
static ldns_status
ldns_wire2pkt_hdr(ldns_pkt *packet, const uint8_t *wire, size_t max, size_t *pos)
{
if (*pos + LDNS_HEADER_SIZE > max) {
return LDNS_STATUS_WIRE_INCOMPLETE_HEADER;
} else {
ldns_pkt_set_id(packet, LDNS_ID_WIRE(wire));
ldns_pkt_set_qr(packet, LDNS_QR_WIRE(wire));
ldns_pkt_set_opcode(packet, LDNS_OPCODE_WIRE(wire));
ldns_pkt_set_aa(packet, LDNS_AA_WIRE(wire));
ldns_pkt_set_tc(packet, LDNS_TC_WIRE(wire));
ldns_pkt_set_rd(packet, LDNS_RD_WIRE(wire));
ldns_pkt_set_ra(packet, LDNS_RA_WIRE(wire));
ldns_pkt_set_ad(packet, LDNS_AD_WIRE(wire));
ldns_pkt_set_cd(packet, LDNS_CD_WIRE(wire));
ldns_pkt_set_rcode(packet, LDNS_RCODE_WIRE(wire));
ldns_pkt_set_qdcount(packet, LDNS_QDCOUNT(wire));
ldns_pkt_set_ancount(packet, LDNS_ANCOUNT(wire));
ldns_pkt_set_nscount(packet, LDNS_NSCOUNT(wire));
ldns_pkt_set_arcount(packet, LDNS_ARCOUNT(wire));
*pos += LDNS_HEADER_SIZE;
return LDNS_STATUS_OK;
}
}
ldns_status
ldns_buffer2pkt_wire(ldns_pkt **packet, const ldns_buffer *buffer)
{
/* lazy */
return ldns_wire2pkt(packet, ldns_buffer_begin(buffer),
ldns_buffer_limit(buffer));
}
ldns_status
ldns_wire2pkt(ldns_pkt **packet_p, const uint8_t *wire, size_t max)
{
size_t pos = 0;
uint16_t i;
ldns_rr *rr;
ldns_pkt *packet = ldns_pkt_new();
ldns_status status = LDNS_STATUS_OK;
uint8_t have_edns = 0;
uint8_t data[4];
status = ldns_wire2pkt_hdr(packet, wire, max, &pos);
LDNS_STATUS_CHECK_GOTO(status, status_error);
for (i = 0; i < ldns_pkt_qdcount(packet); i++) {
status = ldns_wire2rr(&rr, wire, max, &pos, LDNS_SECTION_QUESTION);
if (status == LDNS_STATUS_PACKET_OVERFLOW) {
status = LDNS_STATUS_WIRE_INCOMPLETE_QUESTION;
}
LDNS_STATUS_CHECK_GOTO(status, status_error);
if (!ldns_rr_list_push_rr(ldns_pkt_question(packet), rr)) {
ldns_pkt_free(packet);
return LDNS_STATUS_INTERNAL_ERR;
}
}
for (i = 0; i < ldns_pkt_ancount(packet); i++) {
status = ldns_wire2rr(&rr, wire, max, &pos, LDNS_SECTION_ANSWER);
if (status == LDNS_STATUS_PACKET_OVERFLOW) {
status = LDNS_STATUS_WIRE_INCOMPLETE_ANSWER;
}
LDNS_STATUS_CHECK_GOTO(status, status_error);
if (!ldns_rr_list_push_rr(ldns_pkt_answer(packet), rr)) {
ldns_pkt_free(packet);
return LDNS_STATUS_INTERNAL_ERR;
}
}
for (i = 0; i < ldns_pkt_nscount(packet); i++) {
status = ldns_wire2rr(&rr, wire, max, &pos, LDNS_SECTION_AUTHORITY);
if (status == LDNS_STATUS_PACKET_OVERFLOW) {
status = LDNS_STATUS_WIRE_INCOMPLETE_AUTHORITY;
}
LDNS_STATUS_CHECK_GOTO(status, status_error);
if (!ldns_rr_list_push_rr(ldns_pkt_authority(packet), rr)) {
ldns_pkt_free(packet);
return LDNS_STATUS_INTERNAL_ERR;
}
}
for (i = 0; i < ldns_pkt_arcount(packet); i++) {
status = ldns_wire2rr(&rr, wire, max, &pos, LDNS_SECTION_ADDITIONAL);
if (status == LDNS_STATUS_PACKET_OVERFLOW) {
status = LDNS_STATUS_WIRE_INCOMPLETE_ADDITIONAL;
}
LDNS_STATUS_CHECK_GOTO(status, status_error);
if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_OPT) {
ldns_pkt_set_edns_udp_size(packet, ldns_rr_get_class(rr));
ldns_write_uint32(data, ldns_rr_ttl(rr));
ldns_pkt_set_edns_extended_rcode(packet, data[0]);
ldns_pkt_set_edns_version(packet, data[1]);
ldns_pkt_set_edns_z(packet, ldns_read_uint16(&data[2]));
/* edns might not have rdfs */
if (ldns_rr_rdf(rr, 0)) {
ldns_pkt_set_edns_data(packet, ldns_rdf_clone(ldns_rr_rdf(rr, 0)));
}
ldns_rr_free(rr);
have_edns += 1;
} else if (ldns_rr_get_type(rr) == LDNS_RR_TYPE_TSIG) {
ldns_pkt_set_tsig(packet, rr);
ldns_pkt_set_arcount(packet, ldns_pkt_arcount(packet) - 1);
} else if (!ldns_rr_list_push_rr(ldns_pkt_additional(packet), rr)) {
ldns_pkt_free(packet);
return LDNS_STATUS_INTERNAL_ERR;
}
}
ldns_pkt_set_size(packet, max);
if(have_edns)
ldns_pkt_set_arcount(packet, ldns_pkt_arcount(packet)
- have_edns);
packet->_edns_present = have_edns;
*packet_p = packet;
return status;
status_error:
ldns_pkt_free(packet);
return status;
}
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