summaryrefslogtreecommitdiff
path: root/src/resolve/resolved-dns-packet.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/resolve/resolved-dns-packet.c')
-rw-r--r--src/resolve/resolved-dns-packet.c95
1 files changed, 64 insertions, 31 deletions
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index 4e069ab4cb..14faf9e4ab 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -80,7 +80,7 @@ void dns_packet_set_flags(DnsPacket *p, bool dnssec_checking_disabled, bool trun
h->flags = htobe16(DNS_PACKET_MAKE_FLAGS(0 /* qr */,
0 /* opcode */,
0 /* c */,
- 0/* tc */,
+ 0 /* tc */,
0 /* t */,
0 /* ra */,
0 /* ad */,
@@ -438,10 +438,15 @@ int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_
return 0;
}
-int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start) {
+int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, bool canonical_candidate, size_t *start) {
uint8_t *w;
int r;
+ /* Append a label to a packet. Optionally, does this in DNSSEC
+ * canonical form, if this label is marked as a candidate for
+ * it, and the canonical form logic is enabled for the
+ * packet */
+
assert(p);
assert(d);
@@ -454,7 +459,7 @@ int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start
*(w++) = (uint8_t) l;
- if (p->canonical_form) {
+ if (p->canonical_form && canonical_candidate) {
size_t i;
/* Generate in canonical form, as defined by DNSSEC
@@ -479,6 +484,7 @@ int dns_packet_append_name(
DnsPacket *p,
const char *name,
bool allow_compression,
+ bool canonical_candidate,
size_t *start) {
size_t saved_size;
@@ -533,7 +539,7 @@ int dns_packet_append_name(
if (k > 0)
r = k;
- r = dns_packet_append_label(p, label, r, &n);
+ r = dns_packet_append_label(p, label, r, canonical_candidate, &n);
if (r < 0)
goto fail;
@@ -574,7 +580,7 @@ int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *k, size_t *start)
saved_size = p->size;
- r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, NULL);
+ r = dns_packet_append_name(p, DNS_RESOURCE_KEY_NAME(k), true, true, NULL);
if (r < 0)
goto fail;
@@ -596,7 +602,7 @@ fail:
return r;
}
-static int dns_packet_append_type_window(DnsPacket *p, uint8_t window, uint8_t length, uint8_t *types, size_t *start) {
+static int dns_packet_append_type_window(DnsPacket *p, uint8_t window, uint8_t length, const uint8_t *types, size_t *start) {
size_t saved_size;
int r;
@@ -653,15 +659,16 @@ static int dns_packet_append_types(DnsPacket *p, Bitmap *types, size_t *start) {
}
window = n >> 8;
-
entry = n & 255;
bitmaps[entry / 8] |= 1 << (7 - (entry % 8));
}
- r = dns_packet_append_type_window(p, window, entry / 8 + 1, bitmaps, NULL);
- if (r < 0)
- goto fail;
+ if (bitmaps[entry / 8] != 0) {
+ r = dns_packet_append_type_window(p, window, entry / 8 + 1, bitmaps, NULL);
+ if (r < 0)
+ goto fail;
+ }
if (start)
*start = saved_size;
@@ -762,14 +769,14 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
if (r < 0)
goto fail;
- r = dns_packet_append_name(p, rr->srv.name, true, NULL);
+ r = dns_packet_append_name(p, rr->srv.name, true, false, NULL);
break;
case DNS_TYPE_PTR:
case DNS_TYPE_NS:
case DNS_TYPE_CNAME:
case DNS_TYPE_DNAME:
- r = dns_packet_append_name(p, rr->ptr.name, true, NULL);
+ r = dns_packet_append_name(p, rr->ptr.name, true, false, NULL);
break;
case DNS_TYPE_HINFO:
@@ -812,11 +819,11 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
break;
case DNS_TYPE_SOA:
- r = dns_packet_append_name(p, rr->soa.mname, true, NULL);
+ r = dns_packet_append_name(p, rr->soa.mname, true, false, NULL);
if (r < 0)
goto fail;
- r = dns_packet_append_name(p, rr->soa.rname, true, NULL);
+ r = dns_packet_append_name(p, rr->soa.rname, true, false, NULL);
if (r < 0)
goto fail;
@@ -844,7 +851,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
if (r < 0)
goto fail;
- r = dns_packet_append_name(p, rr->mx.exchange, true, NULL);
+ r = dns_packet_append_name(p, rr->mx.exchange, true, false, NULL);
break;
case DNS_TYPE_LOC:
@@ -948,7 +955,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
if (r < 0)
goto fail;
- r = dns_packet_append_name(p, rr->rrsig.signer, false, NULL);
+ r = dns_packet_append_name(p, rr->rrsig.signer, false, true, NULL);
if (r < 0)
goto fail;
@@ -956,7 +963,7 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
break;
case DNS_TYPE_NSEC:
- r = dns_packet_append_name(p, rr->nsec.next_domain_name, false, NULL);
+ r = dns_packet_append_name(p, rr->nsec.next_domain_name, false, false, NULL);
if (r < 0)
goto fail;
@@ -1448,9 +1455,9 @@ fail:
return r;
}
-int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) {
+int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, bool *ret_cache_flush, size_t *start) {
_cleanup_free_ char *name = NULL;
- bool cache_flush = true;
+ bool cache_flush = false;
uint16_t class, type;
DnsResourceKey *key;
size_t saved_rindex;
@@ -1476,10 +1483,10 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) {
if (p->protocol == DNS_PROTOCOL_MDNS) {
/* See RFC6762, Section 10.2 */
- if (class & MDNS_RR_CACHE_FLUSH)
+ if (type != DNS_TYPE_OPT && (class & MDNS_RR_CACHE_FLUSH)) {
class &= ~MDNS_RR_CACHE_FLUSH;
- else
- cache_flush = false;
+ cache_flush = true;
+ }
}
key = dns_resource_key_new_consume(class, type, name);
@@ -1488,11 +1495,11 @@ int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start) {
goto fail;
}
- key->cache_flush = cache_flush;
-
name = NULL;
*ret = key;
+ if (ret_cache_flush)
+ *ret_cache_flush = cache_flush;
if (start)
*start = saved_rindex;
@@ -1508,11 +1515,12 @@ static bool loc_size_ok(uint8_t size) {
return m <= 9 && e <= 9 && (m > 0 || e == 0);
}
-int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
+int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, bool *ret_cache_flush, size_t *start) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
size_t saved_rindex, offset;
uint16_t rdlength;
+ bool cache_flush;
int r;
assert(p);
@@ -1520,11 +1528,11 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
saved_rindex = p->rindex;
- r = dns_packet_read_key(p, &key, NULL);
+ r = dns_packet_read_key(p, &key, &cache_flush, NULL);
if (r < 0)
goto fail;
- if (key->class == DNS_CLASS_ANY ||
+ if (!dns_class_is_valid_rr(key->class)||
!dns_type_is_valid_rr(key->type)) {
r = -EBADMSG;
goto fail;
@@ -1848,7 +1856,7 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
case DNS_TYPE_NSEC: {
/*
- * RFC6762, section 18.14 explicly states mDNS should use name compression.
+ * RFC6762, section 18.14 explictly states mDNS should use name compression.
* This contradicts RFC3845, section 2.1.1
*/
@@ -1932,6 +1940,8 @@ int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start) {
*ret = rr;
rr = NULL;
+ if (ret_cache_flush)
+ *ret_cache_flush = cache_flush;
if (start)
*start = saved_rindex;
@@ -1964,11 +1974,17 @@ int dns_packet_extract(DnsPacket *p) {
for (i = 0; i < n; i++) {
_cleanup_(dns_resource_key_unrefp) DnsResourceKey *key = NULL;
+ bool cache_flush;
- r = dns_packet_read_key(p, &key, NULL);
+ r = dns_packet_read_key(p, &key, &cache_flush, NULL);
if (r < 0)
goto finish;
+ if (cache_flush) {
+ r = -EBADMSG;
+ goto finish;
+ }
+
if (!dns_type_is_valid_query(key->type)) {
r = -EBADMSG;
goto finish;
@@ -1990,13 +2006,19 @@ int dns_packet_extract(DnsPacket *p) {
for (i = 0; i < n; i++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
+ bool cache_flush;
- r = dns_packet_read_rr(p, &rr, NULL);
+ r = dns_packet_read_rr(p, &rr, &cache_flush, NULL);
if (r < 0)
goto finish;
if (rr->key->type == DNS_TYPE_OPT) {
+ if (!dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key))) {
+ r = -EBADMSG;
+ goto finish;
+ }
+
/* The OPT RR is only valid in the Additional section */
if (i < DNS_PACKET_ANCOUNT(p) + DNS_PACKET_NSCOUNT(p)) {
r = -EBADMSG;
@@ -2011,7 +2033,18 @@ int dns_packet_extract(DnsPacket *p) {
p->opt = dns_resource_record_ref(rr);
} else {
- r = dns_answer_add(answer, rr, p->ifindex);
+
+ /* According to RFC 4795, section
+ * 2.9. only the RRs from the Answer
+ * section shall be cached. Hence mark
+ * only those RRs as cacheable by
+ * default, but not the ones from the
+ * Additional or Authority
+ * sections. */
+
+ r = dns_answer_add(answer, rr, p->ifindex,
+ (i < DNS_PACKET_ANCOUNT(p) ? DNS_ANSWER_CACHEABLE : 0) |
+ (p->protocol == DNS_PROTOCOL_MDNS && !cache_flush ? DNS_ANSWER_SHARED_OWNER : 0));
if (r < 0)
goto finish;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2025-01-10 22:03:15 +0000