/** calculate the size of one rr */
static int
calc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr)
{
const sldns_rr_descriptor* desc;
uint16_t pkt_len; /* length of rr inside the packet */
rr->size = sizeof(uint16_t); /* the rdatalen */
sldns_buffer_skip(pkt, 4); /* skip ttl */
pkt_len = sldns_buffer_read_u16(pkt);
if(sldns_buffer_remaining(pkt) < pkt_len)
return 0;
desc = sldns_rr_descript(type);
if(pkt_len > 0 && desc && desc->_dname_count > 0) {
int count = (int)desc->_dname_count;
int rdf = 0;
size_t len;
size_t oldpos;
/* skip first part. */
while(pkt_len > 0 && count) {
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
/* decompress every domain name */
oldpos = sldns_buffer_position(pkt);
if((len = pkt_dname_len(pkt)) == 0)
return 0; /* malformed dname */
if(sldns_buffer_position(pkt)-oldpos > pkt_len)
return 0; /* dname exceeds rdata */
pkt_len -= sldns_buffer_position(pkt)-oldpos;
rr->size += len;
count--;
len = 0;
break;
case LDNS_RDF_TYPE_STR:
if(pkt_len < 1) {
/* NOTREACHED, due to 'while(>0)' */
return 0; /* len byte exceeds rdata */
}
len = sldns_buffer_current(pkt)[0] + 1;
break;
default:
len = get_rdf_size(desc->_wireformat[rdf]);
}
if(len) {
if(pkt_len < len)
return 0; /* exceeds rdata */
pkt_len -= len;
sldns_buffer_skip(pkt, (ssize_t)len);
rr->size += len;
}
rdf++;
}
}
/* remaining rdata */
rr->size += pkt_len;
sldns_buffer_skip(pkt, (ssize_t)pkt_len);
return 1;
}
/** compress domain names in rdata, return RETVAL_* */
static int
compress_rdata(sldns_buffer* pkt, uint8_t* rdata, size_t todolen,
struct regional* region, struct compress_tree_node** tree,
const sldns_rr_descriptor* desc)
{
int labs, r, rdf = 0;
size_t dname_len, len, pos = sldns_buffer_position(pkt);
uint8_t count = desc->_dname_count;
sldns_buffer_skip(pkt, 2); /* rdata len fill in later */
/* space for rdatalen checked for already */
rdata += 2;
todolen -= 2;
while(todolen > 0 && count) {
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
labs = dname_count_size_labels(rdata, &dname_len);
if((r=compress_any_dname(rdata, pkt, labs, region,
tree)) != RETVAL_OK)
return r;
rdata += dname_len;
todolen -= dname_len;
count--;
len = 0;
break;
case LDNS_RDF_TYPE_STR:
len = *rdata + 1;
break;
default:
len = get_rdf_size(desc->_wireformat[rdf]);
}
if(len) {
/* copy over */
if(sldns_buffer_remaining(pkt) < len)
return RETVAL_TRUNC;
sldns_buffer_write(pkt, rdata, len);
todolen -= len;
rdata += len;
}
rdf++;
}
/* copy remainder */
if(todolen > 0) {
if(sldns_buffer_remaining(pkt) < todolen)
return RETVAL_TRUNC;
sldns_buffer_write(pkt, rdata, todolen);
}
/* set rdata len */
sldns_buffer_write_u16_at(pkt, pos, sldns_buffer_position(pkt)-pos-2);
return RETVAL_OK;
}
/** analyze rdata in packet */
static void analyze_rdata(ldns_buffer*pkt, const ldns_rr_descriptor* desc,
uint16_t rdlen)
{
int rdf = 0;
int count = (int)desc->_dname_count;
size_t len, oldpos;
while(rdlen > 0 && count) {
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
oldpos = ldns_buffer_position(pkt);
analyze_dname(pkt);
rdlen -= ldns_buffer_position(pkt)-oldpos;
count --;
len = 0;
break;
case LDNS_RDF_TYPE_STR:
len = ldns_buffer_current(pkt)[0] + 1;
break;
default:
len = get_rdf_size(desc->_wireformat[rdf]);
}
if(len) {
printf(" wf[%d]", (int)len);
ldns_buffer_skip(pkt, (ssize_t)len);
rdlen -= len;
}
rdf++;
}
if(rdlen) {
size_t i;
printf(" remain[%d]\n", (int)rdlen);
for(i=0; i<rdlen; i++)
printf(" %2.2X", (unsigned)ldns_buffer_current(pkt)[i]);
printf("\n");
}
else printf("\n");
ldns_buffer_skip(pkt, (ssize_t)rdlen);
}
/**
* Compare two RR for canonical order, in a field-style sweep.
* @param d: rrset data
* @param desc: ldns wireformat descriptor.
* @param i: first RR to compare
* @param j: first RR to compare
* @return comparison code.
*/
static int
canonical_compare_byfield(struct packed_rrset_data* d,
const sldns_rr_descriptor* desc, size_t i, size_t j)
{
/* sweep across rdata, keep track of some state:
* which rr field, and bytes left in field.
* current position in rdata, length left.
* are we in a dname, length left in a label.
*/
int wfi = -1; /* current wireformat rdata field (rdf) */
int wfj = -1;
uint8_t* di = d->rr_data[i]+2; /* ptr to current rdata byte */
uint8_t* dj = d->rr_data[j]+2;
size_t ilen = d->rr_len[i]-2; /* length left in rdata */
size_t jlen = d->rr_len[j]-2;
int dname_i = 0; /* true if these bytes are part of a name */
int dname_j = 0;
size_t lablen_i = 0; /* 0 for label length byte,for first byte of rdf*/
size_t lablen_j = 0; /* otherwise remaining length of rdf or label */
int dname_num_i = (int)desc->_dname_count; /* decreased at root label */
int dname_num_j = (int)desc->_dname_count;
/* loop while there are rdata bytes available for both rrs,
* and still some lowercasing needs to be done; either the dnames
* have not been reached yet, or they are currently being processed */
while(ilen > 0 && jlen > 0 && (dname_num_i > 0 || dname_num_j > 0)) {
/* compare these two bytes */
/* lowercase if in a dname and not a label length byte */
if( ((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
!= ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj)
) {
if(((dname_i && lablen_i)?(uint8_t)tolower((int)*di):*di)
< ((dname_j && lablen_j)?(uint8_t)tolower((int)*dj):*dj))
return -1;
return 1;
}
ilen--;
jlen--;
/* bytes are equal */
/* advance field i */
/* lablen 0 means that this byte is the first byte of the
* next rdata field; inspect this rdata field and setup
* to process the rest of this rdata field.
* The reason to first read the byte, then setup the rdf,
* is that we are then sure the byte is available and short
* rdata is handled gracefully (even if it is a formerr). */
if(lablen_i == 0) {
if(dname_i) {
/* scan this dname label */
/* capture length to lowercase */
lablen_i = (size_t)*di;
if(lablen_i == 0) {
/* end root label */
dname_i = 0;
dname_num_i--;
/* if dname num is 0, then the
* remainder is binary only */
if(dname_num_i == 0)
lablen_i = ilen;
}
} else {
/* scan this rdata field */
wfi++;
if(desc->_wireformat[wfi]
== LDNS_RDF_TYPE_DNAME) {
dname_i = 1;
lablen_i = (size_t)*di;
if(lablen_i == 0) {
dname_i = 0;
dname_num_i--;
if(dname_num_i == 0)
lablen_i = ilen;
}
} else if(desc->_wireformat[wfi]
== LDNS_RDF_TYPE_STR)
lablen_i = (size_t)*di;
else lablen_i = get_rdf_size(
desc->_wireformat[wfi]) - 1;
}
} else lablen_i--;
/* advance field j; same as for i */
if(lablen_j == 0) {
if(dname_j) {
lablen_j = (size_t)*dj;
if(lablen_j == 0) {
dname_j = 0;
dname_num_j--;
if(dname_num_j == 0)
lablen_j = jlen;
}
} else {
wfj++;
if(desc->_wireformat[wfj]
== LDNS_RDF_TYPE_DNAME) {
dname_j = 1;
lablen_j = (size_t)*dj;
if(lablen_j == 0) {
dname_j = 0;
dname_num_j--;
if(dname_num_j == 0)
lablen_j = jlen;
}
} else if(desc->_wireformat[wfj]
== LDNS_RDF_TYPE_STR)
lablen_j = (size_t)*dj;
else lablen_j = get_rdf_size(
desc->_wireformat[wfj]) - 1;
}
} else lablen_j--;
di++;
dj++;
}
/* end of the loop; because we advanced byte by byte; now we have
* that the rdata has ended, or that there is a binary remainder */
/* shortest first */
if(ilen == 0 && jlen == 0)
return 0;
if(ilen == 0)
return -1;
if(jlen == 0)
return 1;
/* binary remainder, capture comparison in wfi variable */
if((wfi = memcmp(di, dj, (ilen<jlen)?ilen:jlen)) != 0)
return wfi;
if(ilen < jlen)
return -1;
if(jlen < ilen)
return 1;
return 0;
}
/** do the rdata copy */
static int
rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
sldns_pkt_section section)
{
uint16_t pkt_len;
const sldns_rr_descriptor* desc;
*rr_ttl = sldns_read_uint32(rr->ttl_data);
/* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
if(*rr_ttl & 0x80000000U)
*rr_ttl = 0;
if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
/* negative response. see if TTL of SOA record larger than the
* minimum-ttl in the rdata of the SOA record */
if(*rr_ttl > soa_find_minttl(rr))
*rr_ttl = soa_find_minttl(rr);
if(*rr_ttl > MAX_NEG_TTL)
*rr_ttl = MAX_NEG_TTL;
}
if(*rr_ttl < MIN_TTL)
*rr_ttl = MIN_TTL;
if(*rr_ttl < data->ttl)
data->ttl = *rr_ttl;
if(rr->outside_packet) {
/* uncompressed already, only needs copy */
memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
return 1;
}
sldns_buffer_set_position(pkt, (size_t)
(rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
/* insert decompressed size into rdata len stored in memory */
/* -2 because rdatalen bytes are not included. */
pkt_len = htons(rr->size - 2);
memmove(to, &pkt_len, sizeof(uint16_t));
to += 2;
/* read packet rdata len */
pkt_len = sldns_buffer_read_u16(pkt);
if(sldns_buffer_remaining(pkt) < pkt_len)
return 0;
desc = sldns_rr_descript(type);
if(pkt_len > 0 && desc && desc->_dname_count > 0) {
int count = (int)desc->_dname_count;
int rdf = 0;
size_t len;
size_t oldpos;
/* decompress dnames. */
while(pkt_len > 0 && count) {
switch(desc->_wireformat[rdf]) {
case LDNS_RDF_TYPE_DNAME:
oldpos = sldns_buffer_position(pkt);
dname_pkt_copy(pkt, to,
sldns_buffer_current(pkt));
to += pkt_dname_len(pkt);
pkt_len -= sldns_buffer_position(pkt)-oldpos;
count--;
len = 0;
break;
case LDNS_RDF_TYPE_STR:
len = sldns_buffer_current(pkt)[0] + 1;
break;
default:
len = get_rdf_size(desc->_wireformat[rdf]);
break;
}
if(len) {
memmove(to, sldns_buffer_current(pkt), len);
to += len;
sldns_buffer_skip(pkt, (ssize_t)len);
log_assert(len <= pkt_len);
pkt_len -= len;
}
rdf++;
}
}
/* copy remaining rdata */
if(pkt_len > 0)
memmove(to, sldns_buffer_current(pkt), pkt_len);
return 1;
}
