p->size = p->rindex = DNS_PACKET_HEADER_SIZE;
p->allocated = a;
p->protocol = protocol;
+ p->opt_start = p->opt_size = (size_t) -1;
p->n_ref = 1;
*ret = p;
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);
*(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
* RFC 4034, Section 6.2, i.e. all lower-case. */
- for (i = 0; i < l; i++) {
- if (d[i] >= 'A' && d[i] <= 'Z')
- w[i] = (uint8_t) (d[i] - 'A' + 'a');
- else
- w[i] = (uint8_t) d[i];
- }
+ for (i = 0; i < l; i++)
+ w[i] = (uint8_t) ascii_tolower(d[i]);
} else
/* Otherwise, just copy the string unaltered. This is
* essential for DNS-SD, where the casing of labels
DnsPacket *p,
const char *name,
bool allow_compression,
+ bool canonical_candidate,
size_t *start) {
size_t saved_size;
saved_size = p->size;
- while (*name) {
- _cleanup_free_ char *s = NULL;
+ while (!dns_name_is_root(name)) {
+ const char *z = name;
char label[DNS_LABEL_MAX];
size_t n = 0;
int k;
}
}
- s = strdup(name);
- if (!s) {
- r = -ENOMEM;
- goto fail;
- }
-
r = dns_label_unescape(&name, label, sizeof(label));
if (r < 0)
goto fail;
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;
if (allow_compression) {
+ _cleanup_free_ char *s = NULL;
+
+ s = strdup(z);
+ if (!s) {
+ r = -ENOMEM;
+ goto fail;
+ }
+
r = hashmap_ensure_allocated(&p->names, &dns_name_hash_ops);
if (r < 0)
goto fail;
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;
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;
int r;
assert(p);
- assert(types);
saved_size = p->size;
}
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;
}
/* Append the OPT pseudo-RR described in RFC6891 */
-int dns_packet_append_opt_rr(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start) {
+int dns_packet_append_opt(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start) {
size_t saved_size;
int r;
/* we must never advertise supported packet size smaller than the legacy max */
assert(max_udp_size >= DNS_PACKET_UNICAST_SIZE_MAX);
+ if (p->opt_start != (size_t) -1)
+ return -EBUSY;
+
+ assert(p->opt_size == (size_t) -1);
+
saved_size = p->size;
/* empty name */
goto fail;
/* RDLENGTH */
- r = dns_packet_append_uint16(p, 0, NULL);
+
+ if (edns0_do) {
+ /* If DO is on, also append RFC6975 Algorithm data */
+
+ static const uint8_t rfc6975[] = {
+
+ 0, 5, /* OPTION_CODE: DAU */
+ 0, 6, /* LIST_LENGTH */
+ DNSSEC_ALGORITHM_RSASHA1,
+ DNSSEC_ALGORITHM_RSASHA1_NSEC3_SHA1,
+ DNSSEC_ALGORITHM_RSASHA256,
+ DNSSEC_ALGORITHM_RSASHA512,
+ DNSSEC_ALGORITHM_ECDSAP256SHA256,
+ DNSSEC_ALGORITHM_ECDSAP384SHA384,
+
+ 0, 6, /* OPTION_CODE: DHU */
+ 0, 3, /* LIST_LENGTH */
+ DNSSEC_DIGEST_SHA1,
+ DNSSEC_DIGEST_SHA256,
+ DNSSEC_DIGEST_SHA384,
+
+ 0, 7, /* OPTION_CODE: N3U */
+ 0, 1, /* LIST_LENGTH */
+ NSEC3_ALGORITHM_SHA1,
+ };
+
+ r = dns_packet_append_uint16(p, sizeof(rfc6975), NULL);
+ if (r < 0)
+ goto fail;
+
+ r = dns_packet_append_blob(p, rfc6975, sizeof(rfc6975), NULL);
+ } else
+ r = dns_packet_append_uint16(p, 0, NULL);
+
if (r < 0)
goto fail;
+ DNS_PACKET_HEADER(p)->arcount = htobe16(DNS_PACKET_ARCOUNT(p) + 1);
+
+ p->opt_start = saved_size;
+ p->opt_size = p->size - saved_size;
+
if (start)
*start = saved_size;
return r;
}
+int dns_packet_truncate_opt(DnsPacket *p) {
+ assert(p);
+
+ if (p->opt_start == (size_t) -1) {
+ assert(p->opt_size == (size_t) -1);
+ return 0;
+ }
+
+ assert(p->opt_size != (size_t) -1);
+ assert(DNS_PACKET_ARCOUNT(p) > 0);
+
+ if (p->opt_start + p->opt_size != p->size)
+ return -EBUSY;
+
+ dns_packet_truncate(p, p->opt_start);
+ DNS_PACKET_HEADER(p)->arcount = htobe16(DNS_PACKET_ARCOUNT(p) - 1);
+ p->opt_start = p->opt_size = (size_t) -1;
+
+ return 1;
+}
+
int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start) {
size_t saved_size, rdlength_offset, end, rdlength, rds;
int r;
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:
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;
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:
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;
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;
return r;
}
-
int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start) {
assert(p);
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;
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);
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;
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);
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;
if (r < 0)
goto fail;
+ /* RFC 2181, Section 8, suggests to
+ * treat a TTL with the MSB set as a zero TTL. */
+ if (rr->ttl & UINT32_C(0x80000000))
+ rr->ttl = 0;
+
r = dns_packet_read_uint16(p, &rdlength, NULL);
if (r < 0)
goto fail;
*ret = rr;
rr = NULL;
+ if (ret_cache_flush)
+ *ret_cache_flush = cache_flush;
if (start)
*start = saved_rindex;
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;
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) {
- /* The OPT RR is only valid in the Additional section */
- if (i < DNS_PACKET_ANCOUNT(p) + DNS_PACKET_NSCOUNT(p)) {
+ if (!dns_name_is_root(DNS_RESOURCE_KEY_NAME(rr->key))) {
r = -EBADMSG;
goto finish;
}
+ /* Note that we accept the OPT RR in
+ * any section, not just in the
+ * additional section, as some routers
+ * (Belkin!) blindly copy the OPT RR
+ * from the query to the reply packet,
+ * and don't get the section right. */
+
/* Two OPT RRs? */
if (p->opt) {
r = -EBADMSG;
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;
}
projects / thirdparty / systemd.git / blobdiff