/*
* dnstap/dtstream.h - Frame Streams thread for unbound DNSTAP
*
* Copyright (c) 2020, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
/**
* \file
*
* An implementation of the Frame Streams data transport protocol for
* the Unbound DNSTAP message logging facility.
*/
/**
* A message buffer with dnstap messages queued up. It is per-worker.
* It has locks to synchronize. If the buffer is full, a new message
* cannot be added and is discarded. A thread reads the messages and sends
* them.
*/
struct dt_msg_queue {
/** lock of the buffer structure. Hold this lock to add or remove
* entries to the buffer. Release it so that other threads can also
* put messages to log, or a message can be taken out to send away
* by the writer thread.
*/
lock_basic_type lock;
/** the maximum size of the buffer, in bytes */
size_t maxsize;
/** current size of the buffer, in bytes. data bytes of messages.
* If a new message make it more than maxsize, the buffer is full */
size_t cursize;
/** number of messages in the queue */
int msgcount;
/** list of messages. The messages are added to the back and taken
* out from the front. */
struct dt_msg_entry* first, *last;
/** reference to the io thread to wakeup */
struct dt_io_thread* dtio;
/** the wakeup timer for dtio, on worker event base */
struct comm_timer* wakeup_timer;
};
/**
* An entry in the dt_msg_queue. contains one DNSTAP message.
* It is malloced.
*/
struct dt_msg_entry {
/** next in the list. */
struct dt_msg_entry* next;
/** the buffer with the data to send, an encoded DNSTAP message */
void* buf;
/** the length to send. */
size_t len;
};
/**
* Containing buffer and counter for reading DNSTAP frames.
*/
struct dt_frame_read_buf {
/** Buffer containing frame, except length counter(s). */
void* buf;
/** Number of bytes written to buffer. */
size_t buf_count;
/** Capacity of the buffer. */
size_t buf_cap;
/** Frame length field. Will contain the 2nd length field for control
* frames. */
uint32_t frame_len;
/** Number of bytes that have been written to the frame_length field. */
size_t frame_len_done;
/** Set to 1 if this is a control frame, 0 otherwise (ie data frame). */
int control_frame;
};
/**
* IO thread that reads from the queues and writes them.
*/
struct dt_io_thread {
/** the thread number for the dtio thread,
* must be first to cast thread arg to int* in checklock code. */
int threadnum;
/** event base, for event handling */
void* event_base;
/** list of queues that is registered to get written */
struct dt_io_list_item* io_list;
/** iterator point in the io_list, to pick from them in a
* round-robin fashion, instead of only from the first when busy.
* if NULL it means start at the start of the list. */
struct dt_io_list_item* io_list_iter;
/** thread id, of the io thread */
ub_thread_type tid;
/** if the io processing has started */
int started;
/** ssl context for the io thread, for tls connections. type SSL_CTX* */
void* ssl_ctx;
/** if SNI will be used for TLS connections. */
int tls_use_sni;
/** file descriptor that the thread writes to */
int fd;
/** event structure that the thread uses */
void* event;
/** the event is added */
int event_added;
/** event added is a write event */
int event_added_is_write;
/** check for nonblocking connect errors on fd */
int check_nb_connect;
/** ssl for current connection, type SSL* */
void* ssl;
/** true if the handshake for SSL is done, 0 if not */
int ssl_handshake_done;
/** true if briefly the SSL wants a read event, 0 if not.
* This happens during negotiation, we then do not want to write,
* but wait for a read event. */
int ssl_brief_read;
/** true if SSL_read is waiting for a write event. Set back to 0 after
* single write event is handled. */
int ssl_brief_write;
/** the buffer that currently getting written, or NULL if no
* (partial) message written now */
void* cur_msg;
/** length of the current message */
size_t cur_msg_len;
/** number of bytes written for the current message */
size_t cur_msg_done;
/** number of bytes of the length that have been written,
* for the current message length that precedes the frame */
size_t cur_msg_len_done;
/** lock on wakeup_timer_enabled */
lock_basic_type wakeup_timer_lock;
/** if wakeup timer is enabled in some thread */
int wakeup_timer_enabled;
/** command pipe that stops the pipe if closed. Used to quit
* the program. [0] is read, [1] is written to. */
int commandpipe[2];
/** the event to listen to the commandpipe */
void* command_event;
/** the io thread wants to exit */
int want_to_exit;
/** in stop flush, this is nonNULL and references the stop_ev */
void* stop_flush_event;
/** the timer event for connection retries */
void* reconnect_timer;
/** if the reconnect timer is added to the event base */
int reconnect_is_added;
/** the current reconnection timeout, it is increased with
* exponential backoff, in msec */
int reconnect_timeout;
/** If the log server is connected to over unix domain sockets,
* eg. a file is named that is created to log onto. */
int upstream_is_unix;
/** if the log server is connected to over TCP. The ip address and
* port are used */
int upstream_is_tcp;
/** if the log server is connected to over TLS. ip address, port,
* and client certificates can be used for authentication. */
int upstream_is_tls;
/** Perform bidirectional Frame Streams handshake before sending
* messages. */
int is_bidirectional;
/** Set if the READY control frame has been sent. */
int ready_frame_sent;
/** Set if valid ACCEPT frame is received. */
int accept_frame_received;
/** (partially) read frame */
struct dt_frame_read_buf read_frame;
/** the file path for unix socket (or NULL) */
char* socket_path;
/** the ip address and port number (or NULL) */
char* ip_str;
/** is the TLS upstream authenticated by name, if nonNULL,
* we use the same cert bundle as used by other TLS streams. */
char* tls_server_name;
/** are client certificates in use */
int use_client_certs;
/** client cert files: the .key file */
char* client_key_file;
/** client cert files: the .pem file */
char* client_cert_file;
};
/**
* IO thread list of queues list item
* lists a worker queue that should be looked at and sent to the log server.
*/
struct dt_io_list_item {
/** next in the list of buffers to inspect */
struct dt_io_list_item* next;
/** buffer of this worker */
struct dt_msg_queue* queue;
};
/**
* Create new (empty) worker message queue. Limit set to default on max.
* @param base: event base for wakeup timer.
* @return NULL on malloc failure or a new queue (not locked).
*/
struct dt_msg_queue* dt_msg_queue_create(struct comm_base* base);
/**
* Delete a worker message queue. It has to be unlinked from access,
* so it can be deleted without lock worries. The queue is emptied (deleted).
* @param mq: message queue.
*/
void dt_msg_queue_delete(struct dt_msg_queue* mq);
/**
* Submit a message to the queue. The queue is locked by the routine,
* the message is inserted, and then the queue is unlocked so the
* message can be picked up by the writer thread.
* @param mq: message queue.
* @param buf: buffer with message (dnstap contents).
* The buffer must have been malloced by caller. It is linked in
* the queue, and is free()d after use. If the routine fails
* the buffer is freed as well (and nothing happens, the item
* could not be logged).
* @param len: length of buffer.
*/
void dt_msg_queue_submit(struct dt_msg_queue* mq, void* buf, size_t len);
/** timer callback to wakeup dtio thread to process messages */
void mq_wakeup_cb(void* arg);
/**
* Create IO thread.
* @return new io thread object. not yet started. or NULL malloc failure.
*/
struct dt_io_thread* dt_io_thread_create(void);
/**
* Delete the IO thread structure.
* @param dtio: the io thread that is deleted. It must not be running.
*/
void dt_io_thread_delete(struct dt_io_thread* dtio);
/**
* Apply config to the dtio thread
* @param dtio: io thread, not yet started.
* @param cfg: config file struct.
* @return false on malloc failure.
*/
int dt_io_thread_apply_cfg(struct dt_io_thread* dtio,
struct config_file *cfg);
/**
* Register a msg queue to the io thread. It will be polled to see if
* there are messages and those then get removed and sent, when the thread
* is running.
* @param dtio: the io thread.
* @param mq: message queue to register.
* @return false on failure (malloc failure).
*/
int dt_io_thread_register_queue(struct dt_io_thread* dtio,
struct dt_msg_queue* mq);
/**
* Start the io thread
* @param dtio: the io thread.
* @param event_base_nothr: the event base to attach the events to, in case
* we are running without threads. With threads, this is ignored
* and a thread is started to process the dnstap log messages.
* @param numworkers: number of worker threads. The dnstap io thread is
* that number +1 as the threadnumber (in logs).
* @return false on failure.
*/
int dt_io_thread_start(struct dt_io_thread* dtio, void* event_base_nothr,
int numworkers);
/**
* Stop the io thread
* @param dtio: the io thread.
*/
void dt_io_thread_stop(struct dt_io_thread* dtio);
/** callback for the dnstap reconnect, to start reconnecting to output */
void dtio_reconnect_timeout_cb(int fd, short bits, void* arg);
/** callback for the dnstap events, to write to the output */
void dtio_output_cb(int fd, short bits, void* arg);
/** callback for the dnstap commandpipe, to stop the dnstap IO */
void dtio_cmd_cb(int fd, short bits, void* arg);
/** callback for the timer when the thread stops and wants to finish up */
void dtio_stop_timer_cb(int fd, short bits, void* arg);
/** callback for the output when the thread stops and wants to finish up */
void dtio_stop_ev_cb(int fd, short bits, void* arg);
/** callback for unbound-dnstap-socket */
void dtio_tap_callback(int fd, short bits, void* arg);
/** callback for unbound-dnstap-socket */
void dtio_mainfdcallback(int fd, short bits, void* arg);
