202b76ae1a
When the buffer is allocated on the stack we do not have to check for failure everywhere. This is especially useful in debug statements, because we can put dns_resource_key_to_string() call in the debug statement, and we do not need a seperate if (log_level >= LOG_DEBUG) for the conversion. dns_resource_key_to_string() is changed not to provide any whitespace padding. Most callers were stripping the whitespace with strstrip(), and it did not look to well anyway. systemd-resolve output is not column aligned anymore. The result of the conversion is not stored in DnsTransaction object anymore. It is used only for debugging, so it seems fine to generate it when needed. Various debug statements are extended to provide more information.
175 lines
6.2 KiB
C
175 lines
6.2 KiB
C
#pragma once
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/***
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This file is part of systemd.
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Copyright 2014 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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typedef struct DnsTransaction DnsTransaction;
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typedef enum DnsTransactionState DnsTransactionState;
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typedef enum DnsTransactionSource DnsTransactionSource;
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enum DnsTransactionState {
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DNS_TRANSACTION_NULL,
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DNS_TRANSACTION_PENDING,
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DNS_TRANSACTION_VALIDATING,
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DNS_TRANSACTION_RCODE_FAILURE,
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DNS_TRANSACTION_SUCCESS,
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DNS_TRANSACTION_NO_SERVERS,
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DNS_TRANSACTION_TIMEOUT,
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DNS_TRANSACTION_ATTEMPTS_MAX_REACHED,
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DNS_TRANSACTION_INVALID_REPLY,
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DNS_TRANSACTION_ERRNO,
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DNS_TRANSACTION_ABORTED,
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DNS_TRANSACTION_DNSSEC_FAILED,
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DNS_TRANSACTION_NO_TRUST_ANCHOR,
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DNS_TRANSACTION_RR_TYPE_UNSUPPORTED,
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DNS_TRANSACTION_NETWORK_DOWN,
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DNS_TRANSACTION_NOT_FOUND, /* like NXDOMAIN, but when LLMNR/TCP connections fail */
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_DNS_TRANSACTION_STATE_MAX,
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_DNS_TRANSACTION_STATE_INVALID = -1
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};
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#define DNS_TRANSACTION_IS_LIVE(state) IN_SET((state), DNS_TRANSACTION_NULL, DNS_TRANSACTION_PENDING, DNS_TRANSACTION_VALIDATING)
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enum DnsTransactionSource {
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DNS_TRANSACTION_NETWORK,
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DNS_TRANSACTION_CACHE,
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DNS_TRANSACTION_ZONE,
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DNS_TRANSACTION_TRUST_ANCHOR,
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_DNS_TRANSACTION_SOURCE_MAX,
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_DNS_TRANSACTION_SOURCE_INVALID = -1
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};
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#include "resolved-dns-answer.h"
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#include "resolved-dns-packet.h"
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#include "resolved-dns-question.h"
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#include "resolved-dns-scope.h"
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struct DnsTransaction {
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DnsScope *scope;
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DnsResourceKey *key;
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DnsTransactionState state;
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uint16_t id;
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bool tried_stream:1;
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bool initial_jitter_scheduled:1;
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bool initial_jitter_elapsed:1;
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DnsPacket *sent, *received;
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DnsAnswer *answer;
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int answer_rcode;
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DnssecResult answer_dnssec_result;
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DnsTransactionSource answer_source;
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uint32_t answer_nsec_ttl;
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int answer_errno; /* if state is DNS_TRANSACTION_ERRNO */
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/* Indicates whether the primary answer is authenticated,
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* i.e. whether the RRs from answer which directly match the
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* question are authenticated, or, if there are none, whether
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* the NODATA or NXDOMAIN case is. It says nothing about
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* additional RRs listed in the answer, however they have
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* their own DNS_ANSWER_AUTHORIZED FLAGS. Note that this bit
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* is defined different than the AD bit in DNS packets, as
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* that covers more than just the actual primary answer. */
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bool answer_authenticated;
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/* Contains DNSKEY, DS, SOA RRs we already verified and need
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* to authenticate this reply */
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DnsAnswer *validated_keys;
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usec_t start_usec;
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usec_t next_attempt_after;
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sd_event_source *timeout_event_source;
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unsigned n_attempts;
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/* UDP connection logic, if we need it */
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int dns_udp_fd;
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sd_event_source *dns_udp_event_source;
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/* TCP connection logic, if we need it */
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DnsStream *stream;
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/* The active server */
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DnsServer *server;
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/* The features of the DNS server at time of transaction start */
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DnsServerFeatureLevel current_feature_level;
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/* Query candidates this transaction is referenced by and that
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* shall be notified about this specific transaction
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* completing. */
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Set *notify_query_candidates;
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/* Zone items this transaction is referenced by and that shall
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* be notified about completion. */
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Set *notify_zone_items;
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/* Other transactions that this transactions is referenced by
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* and that shall be notified about completion. This is used
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* when transactions want to validate their RRsets, but need
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* another DNSKEY or DS RR to do so. */
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Set *notify_transactions;
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/* The opposite direction: the transactions this transaction
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* created in order to request DNSKEY or DS RRs. */
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Set *dnssec_transactions;
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unsigned block_gc;
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LIST_FIELDS(DnsTransaction, transactions_by_scope);
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};
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int dns_transaction_new(DnsTransaction **ret, DnsScope *s, DnsResourceKey *key);
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DnsTransaction* dns_transaction_free(DnsTransaction *t);
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bool dns_transaction_gc(DnsTransaction *t);
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int dns_transaction_go(DnsTransaction *t);
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void dns_transaction_process_reply(DnsTransaction *t, DnsPacket *p);
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void dns_transaction_complete(DnsTransaction *t, DnsTransactionState state);
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void dns_transaction_notify(DnsTransaction *t, DnsTransaction *source);
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int dns_transaction_validate_dnssec(DnsTransaction *t);
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int dns_transaction_request_dnssec_keys(DnsTransaction *t);
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const char* dns_transaction_state_to_string(DnsTransactionState p) _const_;
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DnsTransactionState dns_transaction_state_from_string(const char *s) _pure_;
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const char* dns_transaction_source_to_string(DnsTransactionSource p) _const_;
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DnsTransactionSource dns_transaction_source_from_string(const char *s) _pure_;
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/* LLMNR Jitter interval, see RFC 4795 Section 7 */
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#define LLMNR_JITTER_INTERVAL_USEC (100 * USEC_PER_MSEC)
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/* mDNS Jitter interval, see RFC 6762 Section 5.2 */
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#define MDNS_JITTER_MIN_USEC (20 * USEC_PER_MSEC)
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#define MDNS_JITTER_RANGE_USEC (100 * USEC_PER_MSEC)
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/* Maximum attempts to send DNS requests, across all DNS servers */
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#define DNS_TRANSACTION_ATTEMPTS_MAX 16
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/* Maximum attempts to send LLMNR requests, see RFC 4795 Section 2.7 */
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#define LLMNR_TRANSACTION_ATTEMPTS_MAX 3
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#define TRANSACTION_ATTEMPTS_MAX(p) ((p) == DNS_PROTOCOL_LLMNR ? LLMNR_TRANSACTION_ATTEMPTS_MAX : DNS_TRANSACTION_ATTEMPTS_MAX)
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