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
index 0000000..ba4a59e
--- /dev/null
+++ 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);