#include "util/data/msgparse.h"
#include "util/data/msgreply.h"
#include "util/data/msgencode.h"
+#include "util/data/dname.h"
#include "util/netevent.h"
#include "util/log.h"
#include "util/net_help.h"
if(q1->qbuflen > q2->qbuflen)
return 1;
log_assert(q1->qbuflen == q2->qbuflen);
- /* will not detect alternate casing of qname */
- if((r = memcmp(q1->qbuf, q2->qbuf, q1->qbuflen)) != 0)
+ log_assert(q1->qbuflen >= 15 /* 10 header, root, type, class */);
+ /* alternate casing of qname is still the same query */
+ if((r = memcmp(q1->qbuf, q2->qbuf, 10)) != 0)
+ return r;
+ if((r = memcmp(q1->qbuf+q1->qbuflen-4, q2->qbuf+q2->qbuflen-4, 4)) != 0)
return r;
if(q1->dnssec != q2->dnssec) {
if(q1->dnssec < q2->dnssec)
return -1;
return 1;
}
+ if((r = query_dname_compare(q1->qbuf+10, q2->qbuf+10)) != 0)
+ return r;
return sockaddr_cmp(&q1->addr, q1->addrlen, &q2->addr, q2->addrlen);
}
outside_network_create(struct comm_base *base, size_t bufsize,
size_t num_ports, char** ifs, int num_ifs, int do_ip4,
int do_ip6, int port_base, size_t num_tcp, struct infra_cache* infra,
- struct ub_randstate* rnd)
+ struct ub_randstate* rnd, int use_caps_for_id)
{
struct outside_network* outnet = (struct outside_network*)
calloc(1, sizeof(struct outside_network));
outnet->infra = infra;
outnet->rnd = rnd;
outnet->svcd_overhead = 0;
+ outnet->use_caps_for_id = use_caps_for_id;
#ifndef INET6
do_ip6 = 0;
#endif
serviced_node_del(&sq->node, NULL);
}
+/** perturb a dname capitalization randomly */
+static void
+serviced_perturb_qname(struct ub_randstate* rnd, uint8_t* qbuf, size_t len)
+{
+ uint8_t lablen;
+ uint8_t* d = qbuf + 10;
+ long int random = 0;
+ int bits = 0;
+ log_assert(len >= 10 + 5 /* offset qname, root, qtype, qclass */);
+ lablen = *d++;
+ while(lablen) {
+ while(lablen--) {
+ /* only perturb A-Z, a-z */
+ if(isalpha((int)*d)) {
+ /* get a random bit */
+ if(bits == 0) {
+ random = ub_random(rnd);
+ bits = 30;
+ }
+ if(random & 0x1) {
+ *d = (uint8_t)toupper((int)*d);
+ } else {
+ *d = (uint8_t)tolower((int)*d);
+ }
+ random >>= 1;
+ bits--;
+ }
+ d++;
+ }
+ lablen = *d++;
+ }
+ if(verbosity >= VERB_ALGO) {
+ char buf[LDNS_MAX_DOMAINLEN+1];
+ dname_str(qbuf+10, buf);
+ verbose(VERB_ALGO, "qname perturbed to %s", buf);
+ }
+}
+
/** put serviced query into a buffer */
static void
serviced_encode(struct serviced_query* sq, ldns_buffer* buff, int with_edns)
{
+ /* if we are using 0x20 bits for ID randomness, perturb them */
+ if(sq->outnet->use_caps_for_id) {
+ serviced_perturb_qname(sq->outnet->rnd, sq->qbuf, sq->qbuflen);
+ }
/* generate query */
ldns_buffer_clear(buff);
ldns_buffer_write_u16(buff, 0); /* id placeholder */
return 1;
}
+/** check that perturbed qname is identical */
+static int
+serviced_check_qname(ldns_buffer* pkt, uint8_t* qbuf, size_t qbuflen)
+{
+ uint8_t* d1 = ldns_buffer_at(pkt, 12);
+ uint8_t* d2 = qbuf+10;
+ uint8_t len1, len2;
+ int count = 0;
+ log_assert(qbuflen >= 15 /* 10 header, root, type, class */);
+ len1 = *d1++;
+ len2 = *d2++;
+ if(ldns_buffer_limit(pkt) < 12+1+4) /* packet too small for qname */
+ return 0;
+ while(len1 != 0 || len2 != 0) {
+ if(LABEL_IS_PTR(len1)) {
+ d1 = ldns_buffer_at(pkt, PTR_OFFSET(len1, *d1));
+ if(d1 >= ldns_buffer_at(pkt, ldns_buffer_limit(pkt)))
+ return 0;
+ len1 = *d1++;
+ if(count++ > MAX_COMPRESS_PTRS)
+ return 0;
+ continue;
+ }
+ if(d2 > qbuf+qbuflen)
+ return 0;
+ if(len1 != len2)
+ return 0;
+ if(len1 > LDNS_MAX_LABELLEN)
+ return 0;
+ log_assert(len1 <= LDNS_MAX_LABELLEN);
+ log_assert(len2 <= LDNS_MAX_LABELLEN);
+ log_assert(len1 == len2 && len1 != 0);
+ /* compare the labels - bitwise identical */
+ if(memcmp(d1, d2, len1) != 0)
+ return 0;
+ d1 += len1;
+ d2 += len2;
+ len1 = *d1++;
+ len2 = *d2++;
+ }
+ return 1;
+}
+
/** call the callbacks for a serviced query */
static void
serviced_callbacks(struct serviced_query* sq, int error, struct comm_point* c,
log_assert(rem); /* should have been present */
sq->to_be_deleted = 1;
verbose(VERB_ALGO, "svcd callbacks start");
+ if(sq->outnet->use_caps_for_id && error == NETEVENT_NOERROR && c) {
+ /* noerror and nxdomain must have a qname in reply */
+ if(ldns_buffer_read_u16_at(c->buffer, 4) == 0 &&
+ (LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer))
+ == LDNS_RCODE_NOERROR ||
+ LDNS_RCODE_WIRE(ldns_buffer_begin(c->buffer))
+ == LDNS_RCODE_NXDOMAIN)) {
+ verbose(VERB_OPS, "no qname in reply to check 0x20ID");
+ log_addr(VERB_OPS, "from server",
+ &sq->addr, sq->addrlen);
+ log_buf(VERB_OPS, "for packet", c->buffer);
+ error = NETEVENT_CLOSED;
+ c = NULL;
+ } else if(ldns_buffer_read_u16_at(c->buffer, 4) > 0 &&
+ !serviced_check_qname(c->buffer, sq->qbuf,
+ sq->qbuflen)) {
+ verbose(VERB_OPS, "wrong 0x20-ID in reply qname, "
+ "answer dropped");
+ log_addr(VERB_OPS, "from server",
+ &sq->addr, sq->addrlen);
+ log_buf(VERB_OPS, "for packet", c->buffer);
+ error = NETEVENT_CLOSED;
+ c = NULL;
+ } else {
+ verbose(VERB_ALGO, "good 0x20-ID in reply qname");
+ /* cleanup caps, prettier cache contents. */
+ pkt_dname_tolower(c->buffer,
+ ldns_buffer_at(c->buffer, 12));
+ }
+ }
if(dobackup && c) {
/* make a backup of the query, since the querystate processing
* may send outgoing queries that overwrite the buffer.
projects / thirdparty / unbound.git / commitdiff
