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-rw-r--r--src/resolve/resolved-dns-packet.c40
-rw-r--r--src/resolve/resolved-dns-packet.h8
-rw-r--r--src/resolve/resolved-dns-rr.c46
-rw-r--r--src/resolve/resolved-dns-rr.h8
-rw-r--r--src/resolve/resolved-dns-scope.c6
5 files changed, 94 insertions, 14 deletions
diff --git a/src/resolve/resolved-dns-packet.c b/src/resolve/resolved-dns-packet.c
index 06464324d2..75f31b80f6 100644
--- a/src/resolve/resolved-dns-packet.c
+++ b/src/resolve/resolved-dns-packet.c
@@ -108,6 +108,8 @@ DnsPacket *dns_packet_ref(DnsPacket *p) {
if (!p)
return NULL;
+ assert(!p->on_stack);
+
assert(p->n_ref > 0);
p->n_ref++;
return p;
@@ -126,7 +128,9 @@ static void dns_packet_free(DnsPacket *p) {
hashmap_free(p->names);
free(p->_data);
- free(p);
+
+ if (!p->on_stack)
+ free(p);
}
DnsPacket *dns_packet_unref(DnsPacket *p) {
@@ -380,7 +384,7 @@ int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_
}
int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start) {
- void *w;
+ uint8_t *w;
int r;
assert(p);
@@ -389,12 +393,29 @@ int dns_packet_append_label(DnsPacket *p, const char *d, size_t l, size_t *start
if (l > DNS_LABEL_MAX)
return -E2BIG;
- r = dns_packet_extend(p, 1 + l, &w, start);
+ r = dns_packet_extend(p, 1 + l, (void**) &w, start);
if (r < 0)
return r;
- ((uint8_t*) w)[0] = (uint8_t) l;
- memcpy(((uint8_t*) w) + 1, d, l);
+ *(w++) = (uint8_t) l;
+
+ if (p->canonical_form) {
+ 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];
+ }
+ } else
+ /* Otherwise, just copy the string unaltered. This is
+ * essential for DNS-SD, where the casing of labels
+ * matters and needs to be retained. */
+ memcpy(w, d, l);
return 0;
}
@@ -647,8 +668,8 @@ fail:
return r;
}
-int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start) {
- size_t saved_size, rdlength_offset, end, rdlength;
+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;
assert(p);
@@ -669,6 +690,8 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
if (r < 0)
goto fail;
+ rds = p->size - saved_size;
+
switch (rr->unparseable ? _DNS_TYPE_INVALID : rr->key->type) {
case DNS_TYPE_SRV:
@@ -947,6 +970,9 @@ int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *star
if (start)
*start = saved_size;
+ if (rdata_start)
+ *rdata_start = rds;
+
return 0;
fail:
diff --git a/src/resolve/resolved-dns-packet.h b/src/resolve/resolved-dns-packet.h
index b236333f61..853c94fe76 100644
--- a/src/resolve/resolved-dns-packet.h
+++ b/src/resolve/resolved-dns-packet.h
@@ -88,8 +88,10 @@ struct DnsPacket {
uint16_t sender_port, destination_port;
uint32_t ttl;
- bool extracted;
- bool refuse_compression;
+ bool on_stack:1;
+ bool extracted:1;
+ bool refuse_compression:1;
+ bool canonical_form:1;
};
static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) {
@@ -162,7 +164,7 @@ int dns_packet_append_raw_string(DnsPacket *p, const void *s, size_t size, size_
int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, size_t *start);
int dns_packet_append_name(DnsPacket *p, const char *name, bool allow_compression, size_t *start);
int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start);
-int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start);
+int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start, size_t *rdata_start);
int dns_packet_append_opt_rr(DnsPacket *p, uint16_t max_udp_size, bool edns0_do, size_t *start);
void dns_packet_truncate(DnsPacket *p, size_t sz);
diff --git a/src/resolve/resolved-dns-rr.c b/src/resolve/resolved-dns-rr.c
index 09fe9725a2..1224eeaf25 100644
--- a/src/resolve/resolved-dns-rr.c
+++ b/src/resolve/resolved-dns-rr.c
@@ -416,6 +416,7 @@ DnsResourceRecord* dns_resource_record_unref(DnsResourceRecord *rr) {
free(rr->generic.data);
}
+ free(rr->wire_format);
dns_resource_key_unref(rr->key);
}
@@ -994,6 +995,51 @@ int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret) {
return 0;
}
+int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical) {
+
+ DnsPacket packet = {
+ .n_ref = 1,
+ .protocol = DNS_PROTOCOL_DNS,
+ .on_stack = true,
+ .refuse_compression = true,
+ .canonical_form = canonical,
+ };
+
+ size_t start, rds;
+ int r;
+
+ assert(rr);
+
+ /* Generates the RR in wire-format, optionally in the
+ * canonical form as discussed in the DNSSEC RFC 4034, Section
+ * 6.2. We allocate a throw-away DnsPacket object on the stack
+ * here, because we need some book-keeping for memory
+ * management, and can reuse the DnsPacket serializer, that
+ * can generate the canonical form, too, but also knows label
+ * compression and suchlike. */
+
+ if (rr->wire_format && rr->wire_format_canonical == canonical)
+ return 0;
+
+ r = dns_packet_append_rr(&packet, rr, &start, &rds);
+ if (r < 0)
+ return r;
+
+ assert(start == 0);
+ assert(packet._data);
+
+ free(rr->wire_format);
+ rr->wire_format = packet._data;
+ rr->wire_format_size = packet.size;
+ rr->wire_format_rdata_offset = rds;
+ rr->wire_format_canonical = canonical;
+
+ packet._data = NULL;
+ dns_packet_unref(&packet);
+
+ return 0;
+}
+
const char *dns_class_to_string(uint16_t class) {
switch (class) {
diff --git a/src/resolve/resolved-dns-rr.h b/src/resolve/resolved-dns-rr.h
index ac4256b882..c51419cb94 100644
--- a/src/resolve/resolved-dns-rr.h
+++ b/src/resolve/resolved-dns-rr.h
@@ -57,7 +57,11 @@ struct DnsResourceRecord {
unsigned n_ref;
DnsResourceKey *key;
uint32_t ttl;
- bool unparseable;
+ bool unparseable:1;
+ bool wire_format_canonical:1;
+ void *wire_format;
+ size_t wire_format_size;
+ size_t wire_format_rdata_offset;
union {
struct {
void *data;
@@ -209,6 +213,8 @@ int dns_resource_record_equal(const DnsResourceRecord *a, const DnsResourceRecor
int dns_resource_record_to_string(const DnsResourceRecord *rr, char **ret);
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsResourceRecord*, dns_resource_record_unref);
+int dns_resource_record_to_wire_format(DnsResourceRecord *rr, bool canonical);
+
DnsTxtItem *dns_txt_item_free_all(DnsTxtItem *i);
bool dns_txt_item_equal(DnsTxtItem *a, DnsTxtItem *b);
diff --git a/src/resolve/resolved-dns-scope.c b/src/resolve/resolved-dns-scope.c
index 09e6872d26..846280e8b8 100644
--- a/src/resolve/resolved-dns-scope.c
+++ b/src/resolve/resolved-dns-scope.c
@@ -549,7 +549,7 @@ static int dns_scope_make_reply_packet(
if (answer) {
for (i = 0; i < answer->n_rrs; i++) {
- r = dns_packet_append_rr(p, answer->items[i].rr, NULL);
+ r = dns_packet_append_rr(p, answer->items[i].rr, NULL, NULL);
if (r < 0)
return r;
}
@@ -559,7 +559,7 @@ static int dns_scope_make_reply_packet(
if (soa) {
for (i = 0; i < soa->n_rrs; i++) {
- r = dns_packet_append_rr(p, soa->items[i].rr, NULL);
+ r = dns_packet_append_rr(p, soa->items[i].rr, NULL, NULL);
if (r < 0)
return r;
}
@@ -733,7 +733,7 @@ static int dns_scope_make_conflict_packet(
if (r < 0)
return r;
- r = dns_packet_append_rr(p, rr, NULL);
+ r = dns_packet_append_rr(p, rr, NULL, NULL);
if (r < 0)
return r;
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-04 11:08:28 +0000