int
query_info_parse(struct query_info* m, ldns_buffer* query)
{
uint8_t* q = ldns_buffer_begin(query);
/* minimum size: header + \0 + qtype + qclass */
if(ldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
return 0;
if(LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY ||
LDNS_QDCOUNT(q) != 1 || ldns_buffer_position(query) != 0)
return 0;
ldns_buffer_skip(query, LDNS_HEADER_SIZE);
m->qname = ldns_buffer_current(query);
if((m->qname_len = query_dname_len(query)) == 0)
return 0; /* parse error */
if(ldns_buffer_remaining(query) < 4)
return 0; /* need qtype, qclass */
m->qtype = ldns_buffer_read_u16(query);
m->qclass = ldns_buffer_read_u16(query);
return 1;
}
/** analyse pkt */
static void analyze(ldns_buffer* pkt)
{
uint16_t i, f, qd, an, ns, ar;
int rrnum = 0;
printf("packet length %d\n", (int)ldns_buffer_limit(pkt));
if(ldns_buffer_limit(pkt) < 12) return;
i = ldns_buffer_read_u16(pkt);
printf("id (hostorder): %d (0x%x)\n", (int)i, (unsigned)i);
f = ldns_buffer_read_u16(pkt);
printf("flags: 0x%x\n", (unsigned)f);
qd = ldns_buffer_read_u16(pkt);
printf("qdcount: %d\n", (int)qd);
an = ldns_buffer_read_u16(pkt);
printf("ancount: %d\n", (int)an);
ns = ldns_buffer_read_u16(pkt);
printf("nscount: %d\n", (int)ns);
ar = ldns_buffer_read_u16(pkt);
printf("arcount: %d\n", (int)ar);
printf(";-- query section\n");
while(ldns_buffer_remaining(pkt) > 0) {
if(rrnum == (int)qd)
printf(";-- answer section\n");
if(rrnum == (int)qd+(int)an)
printf(";-- authority section\n");
if(rrnum == (int)qd+(int)an+(int)ns)
printf(";-- additional section\n");
printf("rr %d ", rrnum);
analyze_rr(pkt, rrnum < (int)qd);
rrnum++;
}
}
/** analyze rr in packet */
static void analyze_rr(ldns_buffer* pkt, int q)
{
uint16_t type, dclass, len;
uint32_t ttl;
analyze_dname(pkt);
type = ldns_buffer_read_u16(pkt);
dclass = ldns_buffer_read_u16(pkt);
printf("type %s(%d)", ldns_rr_descript(type)?
ldns_rr_descript(type)->_name: "??" , (int)type);
printf(" class %s(%d) ", ldns_lookup_by_id(ldns_rr_classes,
(int)dclass)?ldns_lookup_by_id( ldns_rr_classes,
(int)dclass)->name:"??", (int)dclass);
if(q) {
printf("\n");
} else {
ttl = ldns_buffer_read_u32(pkt);
printf(" ttl %d (0x%x)", (int)ttl, (unsigned)ttl);
len = ldns_buffer_read_u16(pkt);
printf(" rdata len %d:\n", (int)len);
if(ldns_rr_descript(type))
analyze_rdata(pkt, ldns_rr_descript(type), len);
else ldns_buffer_skip(pkt, (ssize_t)len);
}
}
/** do the rdata copy */
static int
rdata_copy(ldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
struct rr_parse* rr, uint32_t* rr_ttl, uint16_t type)
{
uint16_t pkt_len;
const ldns_rr_descriptor* desc;
*rr_ttl = ldns_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(*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;
}
ldns_buffer_set_position(pkt, (size_t)
(rr->ttl_data - ldns_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 = ldns_buffer_read_u16(pkt);
if(ldns_buffer_remaining(pkt) < pkt_len)
return 0;
desc = ldns_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 = ldns_buffer_position(pkt);
dname_pkt_copy(pkt, to,
ldns_buffer_current(pkt));
to += pkt_dname_len(pkt);
pkt_len -= 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]);
break;
}
if(len) {
memmove(to, ldns_buffer_current(pkt), len);
to += len;
ldns_buffer_skip(pkt, (ssize_t)len);
log_assert(len <= pkt_len);
pkt_len -= len;
}
rdf++;
}
}
/* copy remaining rdata */
if(pkt_len > 0)
memmove(to, ldns_buffer_current(pkt), pkt_len);
return 1;
}
