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-rw-r--r--src/resolve/resolved-dns-stream.h128
1 files changed, 128 insertions, 0 deletions
diff --git a/src/resolve/resolved-dns-stream.h b/src/resolve/resolved-dns-stream.h
new file mode 100644
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+++ b/src/resolve/resolved-dns-stream.h
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "sd-event.h"
+
+#include "ordered-set.h"
+#include "socket-util.h"
+
+typedef struct DnsServer DnsServer;
+typedef struct DnsStream DnsStream;
+typedef struct DnsTransaction DnsTransaction;
+typedef struct Manager Manager;
+typedef struct DnsStubListenerExtra DnsStubListenerExtra;
+
+#include "resolved-dns-packet.h"
+#include "resolved-dnstls.h"
+
+/* Various timeouts for establishing TCP connections. First the default time-out for that. */
+#define DNS_STREAM_DEFAULT_TIMEOUT_USEC (10 * USEC_PER_SEC)
+
+/* In the DNS stub, be more friendly for incoming connections, than we are to ourselves for outgoing ones */
+#define DNS_STREAM_STUB_TIMEOUT_USEC (30 * USEC_PER_SEC)
+
+/* In opportunistic TLS mode, lower timeouts */
+#define DNS_STREAM_OPPORTUNISTIC_TLS_TIMEOUT_USEC (3 * USEC_PER_SEC)
+
+/* Once connections are established apply this timeout once nothing happens anymore */
+#define DNS_STREAM_ESTABLISHED_TIMEOUT_USEC (10 * USEC_PER_SEC)
+
+typedef enum DnsStreamType {
+ DNS_STREAM_LOOKUP, /* Outgoing connection to a classic DNS server */
+ DNS_STREAM_LLMNR_SEND, /* Outgoing LLMNR TCP lookup */
+ DNS_STREAM_LLMNR_RECV, /* Incoming LLMNR TCP lookup */
+ DNS_STREAM_STUB, /* Incoming DNS stub connection */
+ _DNS_STREAM_TYPE_MAX,
+ _DNS_STREAM_TYPE_INVALID = -EINVAL,
+} DnsStreamType;
+
+#define DNS_STREAM_WRITE_TLS_DATA 1
+
+/* Streams are used by three subsystems:
+ *
+ * 1. The normal transaction logic when doing a DNS or LLMNR lookup via TCP
+ * 2. The LLMNR logic when accepting a TCP-based lookup
+ * 3. The DNS stub logic when accepting a TCP-based lookup
+ */
+
+struct DnsStream {
+ Manager *manager;
+ unsigned n_ref;
+
+ DnsStreamType type;
+ DnsProtocol protocol;
+
+ int fd;
+ union sockaddr_union peer;
+ socklen_t peer_salen;
+ union sockaddr_union local;
+ socklen_t local_salen;
+ int ifindex;
+ uint32_t ttl;
+ bool identified;
+ bool packet_received; /* At least one packet is received. Used by LLMNR. */
+ uint32_t requested_events;
+
+ /* only when using TCP fast open */
+ union sockaddr_union tfo_address;
+ socklen_t tfo_salen;
+
+#if ENABLE_DNS_OVER_TLS
+ DnsTlsStreamData dnstls_data;
+ uint32_t dnstls_events;
+#endif
+
+ sd_event_source *io_event_source;
+ sd_event_source *timeout_event_source;
+
+ be16_t write_size, read_size;
+ DnsPacket *write_packet, *read_packet;
+ size_t n_written, n_read;
+ OrderedSet *write_queue;
+
+ int (*on_packet)(DnsStream *s, DnsPacket *p);
+ int (*complete)(DnsStream *s, int error);
+
+ LIST_HEAD(DnsTransaction, transactions); /* when used by the transaction logic */
+ DnsServer *server; /* when used by the transaction logic */
+ Set *queries; /* when used by the DNS stub logic */
+
+ /* used when DNS-over-TLS is enabled */
+ bool encrypted:1;
+
+ DnsStubListenerExtra *stub_listener_extra;
+
+ LIST_FIELDS(DnsStream, streams);
+};
+
+int dns_stream_new(
+ Manager *m,
+ DnsStream **ret,
+ DnsStreamType type,
+ DnsProtocol protocol,
+ int fd,
+ const union sockaddr_union *tfo_address,
+ int (on_packet)(DnsStream*, DnsPacket*),
+ int (complete)(DnsStream*, int), /* optional */
+ usec_t connect_timeout_usec);
+#if ENABLE_DNS_OVER_TLS
+int dns_stream_connect_tls(DnsStream *s, void *tls_session);
+#endif
+DnsStream *dns_stream_unref(DnsStream *s);
+DnsStream *dns_stream_ref(DnsStream *s);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(DnsStream*, dns_stream_unref);
+
+int dns_stream_write_packet(DnsStream *s, DnsPacket *p);
+ssize_t dns_stream_writev(DnsStream *s, const struct iovec *iov, size_t iovcnt, int flags);
+
+static inline bool DNS_STREAM_QUEUED(DnsStream *s) {
+ assert(s);
+
+ if (s->fd < 0) /* already stopped? */
+ return false;
+
+ return !!s->write_packet;
+}
+
+void dns_stream_detach(DnsStream *s);