Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 219 insertions, 0 deletions

diff --git a/src/resolve/resolved-dns-transaction.h b/src/resolve/resolved-dns-transaction.h
new file mode 100644
index 0000000..2fd8720
--- /dev/null
+++ b/src/resolve/resolved-dns-transaction.h
@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "sd-event.h"
+#include "in-addr-util.h"
+
+typedef struct DnsTransaction DnsTransaction;
+typedef struct DnsTransactionFinder DnsTransactionFinder;
+typedef enum DnsTransactionState DnsTransactionState;
+typedef enum DnsTransactionSource DnsTransactionSource;
+
+#include "resolved-dns-answer.h"
+#include "resolved-dns-dnssec.h"
+#include "resolved-dns-packet.h"
+#include "resolved-dns-question.h"
+#include "resolved-dns-server.h"
+
+enum DnsTransactionState {
+        DNS_TRANSACTION_NULL,
+        DNS_TRANSACTION_PENDING,
+        DNS_TRANSACTION_VALIDATING,
+        DNS_TRANSACTION_RCODE_FAILURE,
+        DNS_TRANSACTION_SUCCESS,
+        DNS_TRANSACTION_NO_SERVERS,
+        DNS_TRANSACTION_TIMEOUT,
+        DNS_TRANSACTION_ATTEMPTS_MAX_REACHED,
+        DNS_TRANSACTION_INVALID_REPLY,
+        DNS_TRANSACTION_ERRNO,
+        DNS_TRANSACTION_ABORTED,
+        DNS_TRANSACTION_DNSSEC_FAILED,
+        DNS_TRANSACTION_NO_TRUST_ANCHOR,
+        DNS_TRANSACTION_RR_TYPE_UNSUPPORTED,
+        DNS_TRANSACTION_NETWORK_DOWN,
+        DNS_TRANSACTION_NOT_FOUND, /* like NXDOMAIN, but when LLMNR/TCP connections fail */
+        DNS_TRANSACTION_NO_SOURCE, /* All suitable DnsTransactionSource turned off */
+        DNS_TRANSACTION_STUB_LOOP,
+        _DNS_TRANSACTION_STATE_MAX,
+        _DNS_TRANSACTION_STATE_INVALID = -EINVAL,
+};
+
+#define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)
+
+enum DnsTransactionSource {
+        DNS_TRANSACTION_NETWORK,
+        DNS_TRANSACTION_CACHE,
+        DNS_TRANSACTION_ZONE,
+        DNS_TRANSACTION_TRUST_ANCHOR,
+        _DNS_TRANSACTION_SOURCE_MAX,
+        _DNS_TRANSACTION_SOURCE_INVALID = -EINVAL,
+};
+
+struct DnsTransaction {
+        DnsScope *scope;
+
+        DnsResourceKey *key;         /* For regular lookups the RR key to look for */
+        DnsPacket *bypass;           /* For bypass lookups the full original request packet */
+
+        uint64_t query_flags;
+
+        DnsPacket *sent, *received;
+
+        DnsAnswer *answer;
+        int answer_rcode;
+        DnssecResult answer_dnssec_result;
+        DnsTransactionSource answer_source;
+        uint32_t answer_nsec_ttl;
+        int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */
+
+        DnsTransactionState state;
+
+        /* SD_RESOLVED_AUTHENTICATED here indicates whether the primary answer is authenticated, i.e. whether
+         * the RRs from answer which directly match the question are authenticated, or, if there are none,
+         * whether the NODATA or NXDOMAIN case is. It says nothing about additional RRs listed in the answer,
+         * however they have their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit is defined different
+         * than the AD bit in DNS packets, as that covers more than just the actual primary answer. */
+        uint64_t answer_query_flags;
+
+        /* Contains DNSKEY, DS, SOA RRs we already verified and need
+         * to authenticate this reply */
+        DnsAnswer *validated_keys;
+
+        usec_t start_usec;
+        usec_t next_attempt_after;
+        sd_event_source *timeout_event_source;
+        unsigned n_attempts;
+
+        /* UDP connection logic, if we need it */
+        int dns_udp_fd;
+        sd_event_source *dns_udp_event_source;
+
+        /* TCP connection logic, if we need it */
+        DnsStream *stream;
+
+        /* The active server */
+        DnsServer *server;
+
+        /* The features of the DNS server at time of transaction start */
+        DnsServerFeatureLevel current_feature_level;
+
+        /* If we got SERVFAIL back, we retry the lookup, using a lower feature level than we used before. */
+        DnsServerFeatureLevel clamp_feature_level_servfail;
+
+        uint16_t id;
+
+        bool tried_stream:1;
+
+        bool initial_jitter_scheduled:1;
+        bool initial_jitter_elapsed:1;
+
+        bool probing:1;
+
+        bool seen_timeout:1;
+
+        /* Query candidates this transaction is referenced by and that
+         * shall be notified about this specific transaction
+         * completing. */
+        Set *notify_query_candidates, *notify_query_candidates_done;
+
+        /* Zone items this transaction is referenced by and that shall
+         * be notified about completion. */
+        Set *notify_zone_items, *notify_zone_items_done;
+
+        /* Other transactions that this transactions is referenced by
+         * and that shall be notified about completion. This is used
+         * when transactions want to validate their RRsets, but need
+         * another DNSKEY or DS RR to do so. */
+        Set *notify_transactions, *notify_transactions_done;
+
+        /* The opposite direction: the transactions this transaction
+         * created in order to request DNSKEY or DS RRs. */
+        Set *dnssec_transactions;
+
+        unsigned n_picked_servers;
+
+        unsigned block_gc;
+
+        LIST_FIELDS(DnsTransaction, transactions_by_scope);
+        LIST_FIELDS(DnsTransaction, transactions_by_stream);
+        LIST_FIELDS(DnsTransaction, transactions_by_key);
+
+        /* Note: fields should be ordered to minimize alignment gaps. Use pahole! */
+};
+
+int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key, DnsPacket *bypass, uint64_t flags);
+DnsTransaction* dns_transaction_free(DnsTransaction *t);
+
+DnsTransaction* dns_transaction_gc(DnsTransaction *t);
+DEFINE_TRIVIAL_CLEANUP_FUNC(DnsTransaction*, dns_transaction_gc);
+
+int dns_transaction_go(DnsTransaction *t);
+
+void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p, bool encrypted);
+void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state);
+
+void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source);
+int dns_transaction_validate_dnssec(DnsTransaction *t);
+int dns_transaction_request_dnssec_keys(DnsTransaction *t);
+
+static inline DnsResourceKey *dns_transaction_key(DnsTransaction *t) {
+        assert(t);
+
+        /* Return the lookup key of this transaction. Either takes the lookup key from the bypass packet if
+         * we are a bypass transaction. Or take the configured key for regular transactions. */
+
+        if (t->key)
+                return t->key;
+
+        assert(t->bypass);
+
+        return dns_question_first_key(t->bypass->question);
+}
+
+static inline uint64_t dns_transaction_source_to_query_flags(DnsTransactionSource s) {
+
+        switch (s) {
+
+        case DNS_TRANSACTION_NETWORK:
+                return SD_RESOLVED_FROM_NETWORK;
+
+        case DNS_TRANSACTION_CACHE:
+                return SD_RESOLVED_FROM_CACHE;
+
+        case DNS_TRANSACTION_ZONE:
+                return SD_RESOLVED_FROM_ZONE;
+
+        case DNS_TRANSACTION_TRUST_ANCHOR:
+                return SD_RESOLVED_FROM_TRUST_ANCHOR;
+
+        default:
+                return 0;
+        }
+}
+
+const char* dns_transaction_state_to_string(DnsTransactionState p) _const_;
+DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_;
+
+const char* dns_transaction_source_to_string(DnsTransactionSource p) _const_;
+DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_;
+
+/* LLMNR Jitter interval, see RFC 4795 Section 7 */
+#define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC)
+
+/* mDNS probing interval, see RFC 6762 Section 8.1 */
+#define MDNS_PROBING_INTERVAL_USEC (250 * USEC_PER_MSEC)
+
+/* Maximum attempts to send DNS requests, across all DNS servers */
+#define DNS_TRANSACTION_ATTEMPTS_MAX 24
+
+/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */
+#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3
+
+/* Maximum attempts to send MDNS requests, see RFC 6762 Section 8.1 */
+#define MDNS_TRANSACTION_ATTEMPTS_MAX 3
+
+#define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ?        \
+                                     LLMNR_TRANSACTION_ATTEMPTS_MAX :   \
+                                     (p) == DNS_PROTOCOL_MDNS ?         \
+                                     MDNS_TRANSACTION_ATTEMPTS_MAX :    \
+                                     DNS_TRANSACTION_ATTEMPTS_MAX)