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Diffstat (limited to 'src/output/dnssim/internal.h')
| -rw-r--r-- | src/output/dnssim/internal.h | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/src/output/dnssim/internal.h b/src/output/dnssim/internal.h new file mode 100644 index 0000000..b9feddf --- /dev/null +++ b/src/output/dnssim/internal.h @@ -0,0 +1,343 @@ +/* + * Copyright (c) 2019-2020, CZ.NIC, z.s.p.o. + * All rights reserved. + * + * This file is part of dnsjit. + * + * dnsjit is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * dnsjit is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with dnsjit. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __dnsjit_output_dnssim_internal_h +#define __dnsjit_output_dnssim_internal_h + +#include <gnutls/gnutls.h> +#include <nghttp2/nghttp2.h> +#include <uv.h> +#include "core/object/dns.h" +#include "core/object/payload.h" + +#define DNSSIM_MIN_GNUTLS_VERSION 0x030603 +#define DNSSIM_MIN_GNUTLS_ERRORMSG "dnssim tls/https2 transport requires GnuTLS >= 3.6.3" + +#define _self ((_output_dnssim_t*)self) +#define _ERR_MALFORMED -2 +#define _ERR_MSGID -3 +#define _ERR_TC -4 +#define _ERR_QUESTION -5 + +#define _MAX_URI_LEN 65536 +#define MAX_DNSMSG_SIZE 65535 +#define WIRE_BUF_SIZE (MAX_DNSMSG_SIZE + 2 + 16384) /** max tcplen + 2b tcplen + 16kb tls record */ + +typedef struct _output_dnssim_request _output_dnssim_request_t; +typedef struct _output_dnssim_connection _output_dnssim_connection_t; +typedef struct _output_dnssim_client _output_dnssim_client_t; + +/* + * Query-related structures. + */ + +typedef struct _output_dnssim_query _output_dnssim_query_t; +struct _output_dnssim_query { + /* + * Next query in the list. + * + * Currently, next is used for TCP clients/connection, which makes it + * impossible to use for tracking multiple queries of a single request. + * + * TODO: refactor the linked lists to allow query to be part of multiple lists + */ + _output_dnssim_query_t* next; + + output_dnssim_transport_t transport; + _output_dnssim_request_t* req; + + /* Query state, currently used only for TCP. */ + enum { + _OUTPUT_DNSSIM_QUERY_PENDING_WRITE, + _OUTPUT_DNSSIM_QUERY_PENDING_WRITE_CB, + _OUTPUT_DNSSIM_QUERY_PENDING_CLOSE, + _OUTPUT_DNSSIM_QUERY_WRITE_FAILED, + _OUTPUT_DNSSIM_QUERY_SENT, + _OUTPUT_DNSSIM_QUERY_ORPHANED + } state; +}; + +typedef struct _output_dnssim_query_udp _output_dnssim_query_udp_t; +struct _output_dnssim_query_udp { + _output_dnssim_query_t qry; + + uv_udp_t* handle; + uv_buf_t buf; +}; + +typedef struct _output_dnssim_query_tcp _output_dnssim_query_tcp_t; +struct _output_dnssim_query_tcp { + _output_dnssim_query_t qry; + + /* Connection this query is assigned to. */ + _output_dnssim_connection_t* conn; + + uv_write_t write_req; + + /* Send buffers for libuv; 0 is for dnslen, 1 is for dnsmsg. */ + uv_buf_t bufs[2]; + + /* HTTP/2 stream id that was used to send this query. */ + int32_t stream_id; + + /* HTTP/2 expected content length. */ + int32_t content_len; + + /* Receive buffer (currently used only by HTTP/2). */ + uint8_t* recv_buf; + ssize_t recv_buf_len; +}; + +struct _output_dnssim_request { + /* List of queries associated with this request. */ + _output_dnssim_query_t* qry; + + /* Client this request belongs to. */ + _output_dnssim_client_t* client; + + /* The DNS question to be resolved. */ + core_object_payload_t* payload; + core_object_dns_t* dns_q; + const uint8_t* question; + ssize_t question_len; + + /* Timestamps for latency calculation. */ + uint64_t created_at; + uint64_t ended_at; + + /* Timer for tracking timeout of the request. */ + uv_timer_t* timer; + + /* The output component of this request. */ + output_dnssim_t* dnssim; + + /* State of the request. */ + enum { + _OUTPUT_DNSSIM_REQ_ONGOING, + _OUTPUT_DNSSIM_REQ_CLOSING + } state; + + /* Statistics interval in which this request is tracked. */ + output_dnssim_stats_t* stats; +}; + +/* + * Connection-related structures. + */ + +/* Read-state of connection's data stream. */ +typedef enum _output_dnssim_read_state { + _OUTPUT_DNSSIM_READ_STATE_CLEAN, + _OUTPUT_DNSSIM_READ_STATE_DNSLEN, /* Expecting bytes of dnslen. */ + _OUTPUT_DNSSIM_READ_STATE_DNSMSG, /* Expecting bytes of dnsmsg. */ + _OUTPUT_DNSSIM_READ_STATE_INVALID +} _output_dnssim_read_state_t; + +/* TLS-related data for a single connection. */ +typedef struct _output_dnssim_tls_ctx { + gnutls_session_t session; + uint8_t* buf; + ssize_t buf_len; + ssize_t buf_pos; + size_t write_queue_size; +} _output_dnssim_tls_ctx_t; + +/* HTTP2 context for a single connection. */ +typedef struct _output_dnssim_http2_ctx { + nghttp2_session* session; + + /* Query to which the dnsbuf currently being processed belongs to. */ + _output_dnssim_query_tcp_t* current_qry; + + /* Maximum number of concurrent and currently open streams. */ + uint32_t max_concurrent_streams; + uint32_t open_streams; + + /* Flag indicating whether we received the peer's initial SETTINGS frame. */ + bool remote_settings_received; +} _output_dnssim_http2_ctx_t; + +struct _output_dnssim_connection { + _output_dnssim_connection_t* next; + + uv_tcp_t* handle; + + /* Timeout timer for establishing the connection. */ + uv_timer_t* handshake_timer; + + /* Idle timer for connection reuse. rfc7766#section-6.2.3 */ + uv_timer_t* idle_timer; + bool is_idle; + + /* List of queries that have been queued (pending write callback). */ + _output_dnssim_query_t* queued; + + /* List of queries that have been sent over this connection. */ + _output_dnssim_query_t* sent; + + /* Client this connection belongs to. */ + _output_dnssim_client_t* client; + + /* State of the connection. + * Numeric ordering of constants is significant and follows the typical connection lifecycle. + * Ensure new states are added to a proper place. */ + enum { + _OUTPUT_DNSSIM_CONN_INITIALIZED = 0, + _OUTPUT_DNSSIM_CONN_TCP_HANDSHAKE = 10, + _OUTPUT_DNSSIM_CONN_TLS_HANDSHAKE = 20, + _OUTPUT_DNSSIM_CONN_ACTIVE = 30, + _OUTPUT_DNSSIM_CONN_CONGESTED = 35, + _OUTPUT_DNSSIM_CONN_CLOSE_REQUESTED = 38, + _OUTPUT_DNSSIM_CONN_CLOSING = 40, + _OUTPUT_DNSSIM_CONN_CLOSED = 50 + } state; + + /* State of the data stream read. */ + _output_dnssim_read_state_t read_state; + + /* Total length of the expected dns data (either 2 for dnslen, or dnslen itself). */ + size_t dnsbuf_len; + + /* Current position in the receive dns buffer. */ + size_t dnsbuf_pos; + + /* Receive buffer used for incomplete messages or dnslen. */ + char* dnsbuf_data; + bool dnsbuf_free_after_use; + + /* Statistics interval in which the handshake is tracked. */ + output_dnssim_stats_t* stats; + + /* TLS-related data. */ + _output_dnssim_tls_ctx_t* tls; + + /* HTTP/2-related data. */ + _output_dnssim_http2_ctx_t* http2; + + /* Prevents immediate closure of connection. Instead, connection is moved + * to CLOSE_REQUESTED state and setter of this flag is responsible for + * closing the connection when clearing this flag. */ + bool prevent_close; +}; + +/* + * Client structure. + */ + +struct _output_dnssim_client { + /* Dnssim component this client belongs to. */ + output_dnssim_t* dnssim; + + /* List of connections. + * Multiple connections may be used (e.g. some are already closed for writing). + */ + _output_dnssim_connection_t* conn; + + /* List of queries that are pending to be sent over any available connection. */ + _output_dnssim_query_t* pending; + + /* TLS-ticket for session resumption. */ + gnutls_datum_t tls_ticket; +}; + +/* + * DnsSim-related structures. + */ + +typedef struct _output_dnssim_source _output_dnssim_source_t; +struct _output_dnssim_source { + _output_dnssim_source_t* next; + struct sockaddr_storage addr; +}; + +typedef struct _output_dnssim _output_dnssim_t; +struct _output_dnssim { + output_dnssim_t pub; + + uv_loop_t loop; + uv_timer_t stats_timer; + + struct sockaddr_storage target; + _output_dnssim_source_t* source; + output_dnssim_transport_t transport; + + char h2_uri_authority[_MAX_URI_LEN]; + char h2_uri_path[_MAX_URI_LEN]; + bool h2_zero_out_msgid; + output_dnssim_h2_method_t h2_method; + + /* Array of clients, mapped by client ID (ranges from 0 to max_clients). */ + _output_dnssim_client_t* client_arr; + + gnutls_priority_t* tls_priority; + gnutls_certificate_credentials_t tls_cred; + char wire_buf[WIRE_BUF_SIZE]; /* thread-local buffer for processing tls input */ +}; + +/* Provides data for HTTP/2 data frames. */ +typedef struct { + const uint8_t* buf; + size_t len; +} _output_dnssim_https2_data_provider_t; + +/* + * Forward function declarations. + */ + +int _output_dnssim_bind_before_connect(output_dnssim_t* self, uv_handle_t* handle); +int _output_dnssim_create_query_udp(output_dnssim_t* self, _output_dnssim_request_t* req); +int _output_dnssim_create_query_tcp(output_dnssim_t* self, _output_dnssim_request_t* req); +void _output_dnssim_close_query_udp(_output_dnssim_query_udp_t* qry); +void _output_dnssim_close_query_tcp(_output_dnssim_query_tcp_t* qry); +int _output_dnssim_answers_request(_output_dnssim_request_t* req, core_object_dns_t* response); +void _output_dnssim_request_answered(_output_dnssim_request_t* req, core_object_dns_t* msg); +void _output_dnssim_maybe_free_request(_output_dnssim_request_t* req); +void _output_dnssim_on_uv_alloc(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf); +void _output_dnssim_create_request(output_dnssim_t* self, _output_dnssim_client_t* client, core_object_payload_t* payload); +int _output_dnssim_handle_pending_queries(_output_dnssim_client_t* client); +int _output_dnssim_tcp_connect(output_dnssim_t* self, _output_dnssim_connection_t* conn); +void _output_dnssim_tcp_close(_output_dnssim_connection_t* conn); +void _output_dnssim_tcp_write_query(_output_dnssim_connection_t* conn, _output_dnssim_query_tcp_t* qry); +void _output_dnssim_conn_close(_output_dnssim_connection_t* conn); +void _output_dnssim_conn_idle(_output_dnssim_connection_t* conn); +int _output_dnssim_handle_pending_queries(_output_dnssim_client_t* client); +void _output_dnssim_conn_activate(_output_dnssim_connection_t* conn); +void _output_dnssim_conn_maybe_free(_output_dnssim_connection_t* conn); +void _output_dnssim_read_dns_stream(_output_dnssim_connection_t* conn, size_t len, const char* data); +void _output_dnssim_read_dnsmsg(_output_dnssim_connection_t* conn, size_t len, const char* data); + +#if GNUTLS_VERSION_NUMBER >= DNSSIM_MIN_GNUTLS_VERSION +int _output_dnssim_create_query_tls(output_dnssim_t* self, _output_dnssim_request_t* req); +void _output_dnssim_close_query_tls(_output_dnssim_query_tcp_t* qry); +int _output_dnssim_tls_init(_output_dnssim_connection_t* conn); +void _output_dnssim_tls_process_input_data(_output_dnssim_connection_t* conn); +void _output_dnssim_tls_close(_output_dnssim_connection_t* conn); +void _output_dnssim_tls_write_query(_output_dnssim_connection_t* conn, _output_dnssim_query_tcp_t* qry); + +int _output_dnssim_create_query_https2(output_dnssim_t* self, _output_dnssim_request_t* req); +void _output_dnssim_close_query_https2(_output_dnssim_query_tcp_t* qry); +int _output_dnssim_https2_init(_output_dnssim_connection_t* conn); +int _output_dnssim_https2_setup(_output_dnssim_connection_t* conn); +void _output_dnssim_https2_process_input_data(_output_dnssim_connection_t* conn, size_t len, const char* data); +void _output_dnssim_https2_close(_output_dnssim_connection_t* conn); +void _output_dnssim_https2_write_query(_output_dnssim_connection_t* conn, _output_dnssim_query_tcp_t* qry); +#endif + +#endif |