src/quic_tp.c - haproxy - Gitiles

 #include <arpa/inet.h>
 #include <string.h>

 #include <haproxy/global.h>
 #include <haproxy/ncbuf-t.h>
 #include <haproxy/net_helper.h>
 #include <haproxy/quic_conn-t.h>
 #include <haproxy/quic_enc.h>
 #include <haproxy/quic_tp.h>
 #include <haproxy/trace.h>

 #define QUIC_MAX_UDP_PAYLOAD_SIZE     2048

 #define TRACE_SOURCE       &trace_quic

 /* This is the values of some QUIC transport parameters when absent.
  * Should be used to initialize any transport parameters (local or remote)
  * before updating them with customized values.
  */
 struct quic_transport_params quic_dflt_transport_params = {
 	.max_udp_payload_size = QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE,
 	.ack_delay_exponent   = QUIC_TP_DFLT_ACK_DELAY_COMPONENT,
 	.max_ack_delay        = QUIC_TP_DFLT_MAX_ACK_DELAY,
 	.active_connection_id_limit = QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT,
 };

 /* Initialize <dst> transport parameters with default values (when absent)
  * from <quic_dflt_transport_params>.
  * Never fails.
  */
 static void quic_dflt_transport_params_cpy(struct quic_transport_params *dst)
 {
 	dst->max_udp_payload_size = quic_dflt_transport_params.max_udp_payload_size;
 	dst->ack_delay_exponent   = quic_dflt_transport_params.ack_delay_exponent;
 	dst->max_ack_delay        = quic_dflt_transport_params.max_ack_delay;
 	dst->active_connection_id_limit = quic_dflt_transport_params.active_connection_id_limit;
 }

 /* Initialize <p> transport parameters. <server> is a boolean, set if TPs are
  * used by a server (haproxy frontend) else this is for a client (haproxy
  * backend).
  *
  * This must only be used for haproxy local parameters. To initialize peer
  * parameters, see quic_dflt_transport_params_cpy().
  *
  * Never fails.
  */
 void quic_transport_params_init(struct quic_transport_params *p, int server)
 {
 	const uint64_t ncb_size = global.tune.bufsize - NCB_RESERVED_SZ;
 	const int max_streams_bidi = global.tune.quic_frontend_max_streams_bidi;
 	const int max_streams_uni = 3;

 	/* Set RFC default values for unspecified parameters. */
 	quic_dflt_transport_params_cpy(p);

 	/* Set the max_udp_payload_size value. If not would equal to
 	 * QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE
 	 */
 	p->max_udp_payload_size = QUIC_MAX_UDP_PAYLOAD_SIZE;
 	if (server)
 		p->max_idle_timeout = global.tune.quic_frontend_max_idle_timeout;
 	else
 		p->max_idle_timeout = global.tune.quic_backend_max_idle_timeout;

 	p->initial_max_streams_bidi            = max_streams_bidi;
 	p->initial_max_streams_uni             = max_streams_uni;
 	p->initial_max_stream_data_bidi_local  = ncb_size;
 	p->initial_max_stream_data_bidi_remote = ncb_size;
 	p->initial_max_stream_data_uni         = ncb_size;
 	p->initial_max_data = (max_streams_bidi + max_streams_uni) * ncb_size;

 	if (server)
 		p->with_stateless_reset_token  = 1;

 	p->active_connection_id_limit          = 8;

 	p->retry_source_connection_id.len = 0;
 }

 /* Encode <addr> preferred address transport parameter in <buf> without its
  * "type+len" prefix. Note that the IP addresses must be encoded in network byte
  * order.
  * So ->ipv4_addr and ->ipv6_addr, which are buffers, must contained values
  * already encoded in network byte order.
  * It is the responsibility of the caller to check there is enough room in <buf> to encode
  * this address.
  * Never fails.
  */
 static void quic_transport_param_enc_pref_addr_val(unsigned char **buf,
                                                    const unsigned char *end,
                                                    struct tp_preferred_address *addr)
 {
 	write_n16(*buf, addr->ipv4_port);
 	*buf += sizeof addr->ipv4_port;

 	memcpy(*buf, addr->ipv4_addr, sizeof addr->ipv4_addr);
 	*buf += sizeof addr->ipv4_addr;

 	write_n16(*buf, addr->ipv6_port);
 	*buf += sizeof addr->ipv6_port;

 	memcpy(*buf, addr->ipv6_addr, sizeof addr->ipv6_addr);
 	*buf += sizeof addr->ipv6_addr;

 	*(*buf)++ = addr->cid.len;
 	if (addr->cid.len) {
 		memcpy(*buf, addr->cid.data, addr->cid.len);
 		*buf += addr->cid.len;
 	}

 	memcpy(*buf, addr->stateless_reset_token, sizeof addr->stateless_reset_token);
 	*buf += sizeof addr->stateless_reset_token;
 }

 /* Decode into <addr> preferred address transport parameter found in <*buf> buffer.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_dec_pref_addr(struct tp_preferred_address *addr,
                                               const unsigned char **buf,
                                               const unsigned char *end)
 {
 	ssize_t addr_len;

 	addr_len = sizeof addr->ipv4_port + sizeof addr->ipv4_addr;
 	addr_len += sizeof addr->ipv6_port + sizeof addr->ipv6_addr;
 	addr_len += sizeof addr->cid.len;

 	if (end - *buf < addr_len)
 		return 0;

 	addr->ipv4_port = read_n16(*buf);
 	*buf += sizeof addr->ipv4_port;

 	memcpy(addr->ipv4_addr, *buf, sizeof addr->ipv4_addr);
 	*buf += sizeof addr->ipv4_addr;

 	addr->ipv6_port = read_n16(*buf);
 	*buf += sizeof addr->ipv6_port;

 	memcpy(addr->ipv6_addr, *buf, sizeof addr->ipv6_addr);
 	*buf += sizeof addr->ipv6_addr;

 	addr->cid.len = *(*buf)++;
 	if (addr->cid.len) {
 		if (end - *buf > addr->cid.len || addr->cid.len > sizeof addr->cid.data)
 			return 0;
 		memcpy(addr->cid.data, *buf, addr->cid.len);
 		*buf += addr->cid.len;
 	}

 	if (end - *buf != sizeof addr->stateless_reset_token)
 		return 0;

 	memcpy(addr->stateless_reset_token, *buf, end - *buf);
 	*buf += sizeof addr->stateless_reset_token;

 	return *buf == end;
 }

 /* Decode into <v> version information received transport parameters from <*buf>
  * buffer. <server> must be set to 1 for QUIC clients which receive server
  * transport parameters, and 0 for QUIC servers which receive client transport
  * parameters.
  * Also set the QUIC negotiated version into <tp>.
  * Return 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_dec_version_info(struct tp_version_information *tp,
                                                  const unsigned char **buf,
                                                  const unsigned char *end, int server)
 {
 	size_t tp_len = end - *buf;
 	const uint32_t *ver;

 	/* <tp_len> must be a multiple of sizeof(uint32_t) */
 	if (tp_len < sizeof tp->chosen || (tp_len & 0x3))
 		return 0;

 	tp->chosen = ntohl(*(uint32_t *)*buf);
 	/* Must not be null */
 	if (!tp->chosen)
 		return 0;

 	*buf += sizeof tp->chosen;
 	tp->others = (const uint32_t *)*buf;

 	/* Others versions must not be null */
 	for (ver = tp->others; ver < (const uint32_t *)end; ver++) {
 		if (!*ver)
 			return 0;
 	}

 	if (server)
 		/* TODO: not supported */
 		return 0;

 	tp->nb_others = (end - (const unsigned char *)tp->others) / sizeof *tp->others;
 	for (ver = tp->others; ver < (const uint32_t *)end; ver++) {
 		if (!tp->negotiated_version) {
 			int i;

 			for (i = 0; i < quic_versions_nb; i++) {
 				if (ntohl(*ver) == quic_versions[i].num) {
 					tp->negotiated_version = &quic_versions[i];
 					break;
 				}
 			}
 		}

 		if (preferred_version && ntohl(*ver) == preferred_version->num) {
 			tp->negotiated_version = preferred_version;
 			goto out;
 		}
 	}

  out:
 	*buf = end;

 	return 1;
 }

 /* Decode into <p> struct a transport parameter found in <*buf> buffer with
  * <type> as type and <len> as length, depending on <server> boolean value which
  * must be set to 1 for a server (haproxy listener) or 0 for a client (connection
  * to an haproxy server).
  */
 static int quic_transport_param_decode(struct quic_transport_params *p,
                                        int server, uint64_t type,
                                        const unsigned char **buf, size_t len)
 {
 	const unsigned char *end = *buf + len;

 	switch (type) {
 	case QUIC_TP_ORIGINAL_DESTINATION_CONNECTION_ID:
 		if (!server || len > sizeof p->original_destination_connection_id.data)
 			return 0;

 		if (len)
 			memcpy(p->original_destination_connection_id.data, *buf, len);
 		p->original_destination_connection_id.len = len;
 		*buf += len;
 		p->original_destination_connection_id_present = 1;
 		break;
 	case QUIC_TP_INITIAL_SOURCE_CONNECTION_ID:
 		if (len > sizeof p->initial_source_connection_id.data)
 			return 0;

 		if (len)
 			memcpy(p->initial_source_connection_id.data, *buf, len);
 		p->initial_source_connection_id.len = len;
 		*buf += len;
 		p->initial_source_connection_id_present = 1;
 		break;
 	case QUIC_TP_STATELESS_RESET_TOKEN:
 		if (!server || len != sizeof p->stateless_reset_token)
 			return 0;
 		memcpy(p->stateless_reset_token, *buf, len);
 		*buf += len;
 		p->with_stateless_reset_token = 1;
 		break;
 	case QUIC_TP_PREFERRED_ADDRESS:
 		if (!server)
 			return 0;
 		if (!quic_transport_param_dec_pref_addr(&p->preferred_address, buf, *buf + len))
 			return 0;
 		p->with_preferred_address = 1;
 		break;
 	case QUIC_TP_MAX_IDLE_TIMEOUT:
 		if (!quic_dec_int(&p->max_idle_timeout, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_MAX_UDP_PAYLOAD_SIZE:
 		if (!quic_dec_int(&p->max_udp_payload_size, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_DATA:
 		if (!quic_dec_int(&p->initial_max_data, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_LOCAL:
 		if (!quic_dec_int(&p->initial_max_stream_data_bidi_local, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_REMOTE:
 		if (!quic_dec_int(&p->initial_max_stream_data_bidi_remote, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_STREAM_DATA_UNI:
 		if (!quic_dec_int(&p->initial_max_stream_data_uni, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_STREAMS_BIDI:
 		if (!quic_dec_int(&p->initial_max_streams_bidi, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_INITIAL_MAX_STREAMS_UNI:
 		if (!quic_dec_int(&p->initial_max_streams_uni, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_ACK_DELAY_EXPONENT:
 		if (!quic_dec_int(&p->ack_delay_exponent, buf, end) ||
 			p->ack_delay_exponent > QUIC_TP_ACK_DELAY_EXPONENT_LIMIT)
 			return 0;
 		break;
 	case QUIC_TP_MAX_ACK_DELAY:
 		if (!quic_dec_int(&p->max_ack_delay, buf, end) ||
 			p->max_ack_delay > QUIC_TP_MAX_ACK_DELAY_LIMIT)
 			return 0;
 		break;
 	case QUIC_TP_DISABLE_ACTIVE_MIGRATION:
 		/* Zero-length parameter type. */
 		if (len != 0)
 			return 0;
 		p->disable_active_migration = 1;
 		break;
 	case QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT:
 		if (!quic_dec_int(&p->active_connection_id_limit, buf, end))
 			return 0;
 		break;
 	case QUIC_TP_DRAFT_VERSION_INFORMATION:
 		if (!quic_transport_param_dec_version_info(&p->version_information,
 		                                           buf, *buf + len, server))
 			return 0;
 		break;
 	default:
 		*buf += len;
 	};

 	return *buf == end;
 }

 /* Encode <type> and <len> variable length values in <buf>.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_encode_type_len(unsigned char **buf,
                                                 const unsigned char *end,
                                                 uint64_t type, uint64_t len)
 {
 	return quic_enc_int(buf, end, type) && quic_enc_int(buf, end, len);
 }

 /* Decode variable length type and length values of a QUIC transport parameter
  * into <type> and <len> found in <*buf> buffer.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_decode_type_len(uint64_t *type, uint64_t *len,
                                                 const unsigned char **buf,
                                                 const unsigned char *end)
 {
 	return quic_dec_int(type, buf, end) && quic_dec_int(len, buf, end);
 }

 /* Encode <param> bytes stream with <type> as type and <length> as length into buf.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_enc_mem(unsigned char **buf, const unsigned char *end,
                                         uint64_t type, void *param, uint64_t length)
 {
 	if (!quic_transport_param_encode_type_len(buf, end, type, length))
 		return 0;

 	if (end - *buf < length)
 		return 0;

 	if (length)
 		memcpy(*buf, param, length);
 	*buf += length;

 	return 1;
 }

 /* Encode <val> 64-bits value as variable length integer into <buf>.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_enc_int(unsigned char **buf,
                                         const unsigned char *end,
                                         uint64_t type, uint64_t val)
 {
 	size_t len;

 	len = quic_int_getsize(val);

 	return len && quic_transport_param_encode_type_len(buf, end, type, len) &&
 		quic_enc_int(buf, end, val);
 }

 /* Returns the required length in bytes to encode <cid> QUIC connection ID. */
 static inline size_t sizeof_quic_cid(const struct tp_cid *cid)
 {
 	return sizeof cid->len + cid->len;
 }

 /* Encode <addr> preferred address into <buf>.
  * Note that the IP addresses must be encoded in network byte order.
  * So ->ipv4_addr and ->ipv6_addr, which are buffers, must contained
  * values already encoded in network byte order.
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_enc_pref_addr(unsigned char **buf,
                                               const unsigned char *end,
                                               struct tp_preferred_address *addr)
 {
 	uint64_t addr_len = 0;

 	addr_len += sizeof addr->ipv4_port + sizeof addr->ipv4_addr;
 	addr_len += sizeof addr->ipv6_port + sizeof addr->ipv6_addr;
 	addr_len += sizeof_quic_cid(&addr->cid);
 	addr_len += sizeof addr->stateless_reset_token;

 	if (!quic_transport_param_encode_type_len(buf, end, QUIC_TP_PREFERRED_ADDRESS, addr_len))
 		return 0;

 	if (end - *buf < addr_len)
 		return 0;

 	quic_transport_param_enc_pref_addr_val(buf, end, addr);

 	return 1;
 }

 /* Encode version information transport parameters with <chosen_version> as chosen
  * version.
  * Return 1 if succeeded, 0 if not.
  */
 static int quic_transport_param_enc_version_info(unsigned char **buf,
                                                  const unsigned char *end,
                                                  const struct quic_version *chosen_version,
                                                  int server)
 {
 	int i;
 	uint64_t tp_len;
 	uint32_t ver;

 	tp_len = sizeof chosen_version->num + quic_versions_nb * sizeof(uint32_t);
 	if (!quic_transport_param_encode_type_len(buf, end,
 	                                          QUIC_TP_DRAFT_VERSION_INFORMATION,
 	                                          tp_len))
 		return 0;

 	if (end - *buf < tp_len)
 		return 0;

 	/* First: chosen version */
 	ver = htonl(chosen_version->num);
 	memcpy(*buf, &ver, sizeof ver);
 	*buf += sizeof ver;
 	/* For servers: all supported version, chosen included */
 	for (i = 0; i < quic_versions_nb; i++) {
 		ver = htonl(quic_versions[i].num);
 		memcpy(*buf, &ver, sizeof ver);
 		*buf += sizeof ver;
 	}

 	return 1;
 }

 /* Encode <p> transport parameter into <buf> depending on <server> value which
  * must be set to 1 for a server (haproxy listener) or 0 for a client
  * (connection to a haproxy server).
  * Return the number of bytes consumed if succeeded, 0 if not.
  */
 int quic_transport_params_encode(unsigned char *buf,
                                  const unsigned char *end,
                                  struct quic_transport_params *p,
                                  const struct quic_version *chosen_version,
                                  int server)
 {
 	unsigned char *head;
 	unsigned char *pos;

 	head = pos = buf;
 	if (server) {
 		if (!quic_transport_param_enc_mem(&pos, end,
 		                                  QUIC_TP_ORIGINAL_DESTINATION_CONNECTION_ID,
 		                                  p->original_destination_connection_id.data,
 		                                  p->original_destination_connection_id.len))
 			return 0;

 		if (p->retry_source_connection_id.len) {
 			if (!quic_transport_param_enc_mem(&pos, end,
 			                                  QUIC_TP_RETRY_SOURCE_CONNECTION_ID,
 			                                  p->retry_source_connection_id.data,
 			                                  p->retry_source_connection_id.len))
 				return 0;
 		}

 		if (p->with_stateless_reset_token &&
 			!quic_transport_param_enc_mem(&pos, end, QUIC_TP_STATELESS_RESET_TOKEN,
 			                              p->stateless_reset_token,
 			                              sizeof p->stateless_reset_token))
 			return 0;
 		if (p->with_preferred_address &&
 			!quic_transport_param_enc_pref_addr(&pos, end, &p->preferred_address))
 			return 0;
 	}

 	if (!quic_transport_param_enc_mem(&pos, end,
 	                                  QUIC_TP_INITIAL_SOURCE_CONNECTION_ID,
 	                                  p->initial_source_connection_id.data,
 	                                  p->initial_source_connection_id.len))
 		return 0;

 	if (p->max_idle_timeout &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_IDLE_TIMEOUT, p->max_idle_timeout))
 		return 0;

 	/*
 	 * "max_packet_size" transport parameter must be transmitted only if different
 	 * of the default value.
 	 */
 	if (p->max_udp_payload_size != QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_UDP_PAYLOAD_SIZE, p->max_udp_payload_size))
 		return 0;

 	if (p->initial_max_data &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_DATA, p->initial_max_data))
 	    return 0;

 	if (p->initial_max_stream_data_bidi_local &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_LOCAL,
 	                                          p->initial_max_stream_data_bidi_local))
 	    return 0;

 	if (p->initial_max_stream_data_bidi_remote &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_REMOTE,
 	                                          p->initial_max_stream_data_bidi_remote))
 	    return 0;

 	if (p->initial_max_stream_data_uni &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_UNI,
 	                                          p->initial_max_stream_data_uni))
 	    return 0;

 	if (p->initial_max_streams_bidi &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAMS_BIDI,
 	                                          p->initial_max_streams_bidi))
 	    return 0;

 	if (p->initial_max_streams_uni &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAMS_UNI,
 	                                          p->initial_max_streams_uni))
 	    return 0;

 	/*
 	 * "ack_delay_exponent" transport parameter must be transmitted only if different
 	 * of the default value.
 	 */
 	if (p->ack_delay_exponent != QUIC_TP_DFLT_ACK_DELAY_COMPONENT  &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_ACK_DELAY_EXPONENT, p->ack_delay_exponent))
 	    return 0;

 	/*
 	 * "max_ack_delay" transport parameter must be transmitted only if different
 	 * of the default value.
 	 */
 	if (p->max_ack_delay != QUIC_TP_DFLT_MAX_ACK_DELAY &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_ACK_DELAY, p->max_ack_delay))
 	    return 0;

 	/* 0-length value */
 	if (p->disable_active_migration &&
 	    !quic_transport_param_encode_type_len(&pos, end, QUIC_TP_DISABLE_ACTIVE_MIGRATION, 0))
 		return 0;

 	if (p->active_connection_id_limit &&
 	    p->active_connection_id_limit != QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT &&
 	    !quic_transport_param_enc_int(&pos, end, QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT,
 	                                  p->active_connection_id_limit))
 	    return 0;

 	if (!quic_transport_param_enc_version_info(&pos, end, chosen_version, server))
 		return 0;

 	return pos - head;
 }

 /* Decode transport parameters found in <buf> buffer into <p>, depending on
  * <server> boolean value which must be set to 1 for a server (haproxy listener)
  * or 0 for a client (connection to a haproxy server).
  * Returns 1 if succeeded, 0 if not.
  */
 static int quic_transport_params_decode(struct quic_transport_params *p, int server,
                                         const unsigned char *buf,
                                         const unsigned char *end)
 {
 	const unsigned char *pos;
 	uint64_t type, len = 0;

 	pos = buf;

 	while (pos != end) {
 		if (!quic_transport_param_decode_type_len(&type, &len, &pos, end))
 			return 0;

 		if (end - pos < len)
 			return 0;

 		if (!quic_transport_param_decode(p, server, type, &pos, len))
 			return 0;
 	}

 	/*
 	 * A server MUST send original_destination_connection_id transport parameter.
 	 * initial_source_connection_id must be present both for server and client.
 	 */
 	if ((server && !p->original_destination_connection_id_present) ||
 	    !p->initial_source_connection_id_present)
 		return 0;

 	return 1;
 }

 /* Store transport parameters found in <buf> buffer into <qc> QUIC connection
  * depending on <server> value which must be 1 for a server (haproxy listener)
  * or 0 for a client (connection to a haproxy server).
  * Note that peer transport parameters are stored in the TX part of the connection:
  * they are used to send packets to the peer with its transport parameters as
  * limitations.
  * Returns 1 if succeeded, 0 if not.
  */
 int quic_transport_params_store(struct quic_conn *qc, int server,
                                 const unsigned char *buf,
                                 const unsigned char *end)
 {
 	struct quic_transport_params *tx_params = &qc->tx.params;

 	/* initialize peer TPs to RFC default value */
 	quic_dflt_transport_params_cpy(tx_params);

 	if (!quic_transport_params_decode(tx_params, server, buf, end))
 		return 0;

 	return 1;
 }

 /* QUIC server (or haproxy listener) only function.
  * Initialize the local transport parameters <rx_params> from <listener_params>
  * coming from configuration and Initial packet information (destination
  * connection ID, source connection ID, original destination connection ID) from
  * client token.
  * Returns 1 if succeeded, 0 if not.
  */
 int qc_lstnr_params_init(struct quic_conn *qc,
                          const struct quic_transport_params *listener_params,
                          const unsigned char *stateless_reset_token,
                          const unsigned char *dcid, size_t dcidlen,
                          const unsigned char *scid, size_t scidlen,
                          const struct quic_cid *token_odcid)
 {
 	struct quic_transport_params *rx_params = &qc->rx.params;
 	struct tp_cid *odcid_param = &rx_params->original_destination_connection_id;

 	/* Copy the transport parameters. */
 	*rx_params = *listener_params;
 	/* Copy the stateless reset token */
 	memcpy(rx_params->stateless_reset_token, stateless_reset_token,
 	       sizeof rx_params->stateless_reset_token);
 	/* Copy original_destination_connection_id transport parameter. */
 	if (token_odcid->len) {
 		memcpy(odcid_param->data, token_odcid->data, token_odcid->len);
 		odcid_param->len = token_odcid->len;
 		/* Copy retry_source_connection_id transport parameter. */
 		memcpy(rx_params->retry_source_connection_id.data, dcid, dcidlen);
 		rx_params->retry_source_connection_id.len = dcidlen;
 	}
 	else {
 		memcpy(odcid_param->data, dcid, dcidlen);
 		odcid_param->len = dcidlen;
 	}

 	/* Copy the initial source connection ID. */
 	memcpy(rx_params->initial_source_connection_id.data, scid, scidlen);
 	rx_params->initial_source_connection_id.len = scidlen;
 	TRACE_PROTO("\nRX(local) transp. params.", QUIC_EV_TRANSP_PARAMS, qc, rx_params);

 	return 1;
 }
	#include <arpa/inet.h>
	#include <string.h>

	#include <haproxy/global.h>
	#include <haproxy/ncbuf-t.h>
	#include <haproxy/net_helper.h>
	#include <haproxy/quic_conn-t.h>
	#include <haproxy/quic_enc.h>
	#include <haproxy/quic_tp.h>
	#include <haproxy/trace.h>

	#define QUIC_MAX_UDP_PAYLOAD_SIZE 2048

	#define TRACE_SOURCE &trace_quic

	/* This is the values of some QUIC transport parameters when absent.
	* Should be used to initialize any transport parameters (local or remote)
	* before updating them with customized values.
	*/
	struct quic_transport_params quic_dflt_transport_params = {
	.max_udp_payload_size = QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE,
	.ack_delay_exponent = QUIC_TP_DFLT_ACK_DELAY_COMPONENT,
	.max_ack_delay = QUIC_TP_DFLT_MAX_ACK_DELAY,
	.active_connection_id_limit = QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT,
	};

	/* Initialize <dst> transport parameters with default values (when absent)
	* from <quic_dflt_transport_params>.
	* Never fails.
	*/
	static void quic_dflt_transport_params_cpy(struct quic_transport_params *dst)
	{
	dst->max_udp_payload_size = quic_dflt_transport_params.max_udp_payload_size;
	dst->ack_delay_exponent = quic_dflt_transport_params.ack_delay_exponent;
	dst->max_ack_delay = quic_dflt_transport_params.max_ack_delay;
	dst->active_connection_id_limit = quic_dflt_transport_params.active_connection_id_limit;
	}

	/* Initialize <p> transport parameters. <server> is a boolean, set if TPs are
	* used by a server (haproxy frontend) else this is for a client (haproxy
	* backend).
	*
	* This must only be used for haproxy local parameters. To initialize peer
	* parameters, see quic_dflt_transport_params_cpy().
	*
	* Never fails.
	*/
	void quic_transport_params_init(struct quic_transport_params *p, int server)
	{
	const uint64_t ncb_size = global.tune.bufsize - NCB_RESERVED_SZ;
	const int max_streams_bidi = global.tune.quic_frontend_max_streams_bidi;
	const int max_streams_uni = 3;

	/* Set RFC default values for unspecified parameters. */
	quic_dflt_transport_params_cpy(p);

	/* Set the max_udp_payload_size value. If not would equal to
	* QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE
	*/
	p->max_udp_payload_size = QUIC_MAX_UDP_PAYLOAD_SIZE;
	if (server)
	p->max_idle_timeout = global.tune.quic_frontend_max_idle_timeout;
	else
	p->max_idle_timeout = global.tune.quic_backend_max_idle_timeout;

	p->initial_max_streams_bidi = max_streams_bidi;
	p->initial_max_streams_uni = max_streams_uni;
	p->initial_max_stream_data_bidi_local = ncb_size;
	p->initial_max_stream_data_bidi_remote = ncb_size;
	p->initial_max_stream_data_uni = ncb_size;
	p->initial_max_data = (max_streams_bidi + max_streams_uni) * ncb_size;

	if (server)
	p->with_stateless_reset_token = 1;

	p->active_connection_id_limit = 8;

	p->retry_source_connection_id.len = 0;
	}

	/* Encode <addr> preferred address transport parameter in <buf> without its
	* "type+len" prefix. Note that the IP addresses must be encoded in network byte
	* order.
	* So ->ipv4_addr and ->ipv6_addr, which are buffers, must contained values
	* already encoded in network byte order.
	* It is the responsibility of the caller to check there is enough room in <buf> to encode
	* this address.
	* Never fails.
	*/
	static void quic_transport_param_enc_pref_addr_val(unsigned char **buf,
	const unsigned char *end,
	struct tp_preferred_address *addr)
	{
	write_n16(*buf, addr->ipv4_port);
	*buf += sizeof addr->ipv4_port;

	memcpy(*buf, addr->ipv4_addr, sizeof addr->ipv4_addr);
	*buf += sizeof addr->ipv4_addr;

	write_n16(*buf, addr->ipv6_port);
	*buf += sizeof addr->ipv6_port;

	memcpy(*buf, addr->ipv6_addr, sizeof addr->ipv6_addr);
	*buf += sizeof addr->ipv6_addr;

	(buf)++ = addr->cid.len;
	if (addr->cid.len) {
	memcpy(*buf, addr->cid.data, addr->cid.len);
	*buf += addr->cid.len;
	}

	memcpy(*buf, addr->stateless_reset_token, sizeof addr->stateless_reset_token);
	*buf += sizeof addr->stateless_reset_token;
	}

	/* Decode into <addr> preferred address transport parameter found in <*buf> buffer.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_dec_pref_addr(struct tp_preferred_address *addr,
	const unsigned char **buf,
	const unsigned char *end)
	{
	ssize_t addr_len;

	addr_len = sizeof addr->ipv4_port + sizeof addr->ipv4_addr;
	addr_len += sizeof addr->ipv6_port + sizeof addr->ipv6_addr;
	addr_len += sizeof addr->cid.len;

	if (end - *buf < addr_len)
	return 0;

	addr->ipv4_port = read_n16(*buf);
	*buf += sizeof addr->ipv4_port;

	memcpy(addr->ipv4_addr, *buf, sizeof addr->ipv4_addr);
	*buf += sizeof addr->ipv4_addr;

	addr->ipv6_port = read_n16(*buf);
	*buf += sizeof addr->ipv6_port;

	memcpy(addr->ipv6_addr, *buf, sizeof addr->ipv6_addr);
	*buf += sizeof addr->ipv6_addr;

	addr->cid.len = (buf)++;
	if (addr->cid.len) {
	if (end - *buf > addr->cid.len \|\| addr->cid.len > sizeof addr->cid.data)
	return 0;
	memcpy(addr->cid.data, *buf, addr->cid.len);
	*buf += addr->cid.len;
	}

	if (end - *buf != sizeof addr->stateless_reset_token)
	return 0;

	memcpy(addr->stateless_reset_token, buf, end - buf);
	*buf += sizeof addr->stateless_reset_token;

	return *buf == end;
	}

	/* Decode into <v> version information received transport parameters from <*buf>
	* buffer. <server> must be set to 1 for QUIC clients which receive server
	* transport parameters, and 0 for QUIC servers which receive client transport
	* parameters.
	* Also set the QUIC negotiated version into <tp>.
	* Return 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_dec_version_info(struct tp_version_information *tp,
	const unsigned char **buf,
	const unsigned char *end, int server)
	{
	size_t tp_len = end - *buf;
	const uint32_t *ver;

	/* <tp_len> must be a multiple of sizeof(uint32_t) */
	if (tp_len < sizeof tp->chosen \|\| (tp_len & 0x3))
	return 0;

	tp->chosen = ntohl((uint32_t )*buf);
	/* Must not be null */
	if (!tp->chosen)
	return 0;

	*buf += sizeof tp->chosen;
	tp->others = (const uint32_t )buf;

	/* Others versions must not be null */
	for (ver = tp->others; ver < (const uint32_t *)end; ver++) {
	if (!*ver)
	return 0;
	}

	if (server)
	/* TODO: not supported */
	return 0;

	tp->nb_others = (end - (const unsigned char )tp->others) / sizeof tp->others;
	for (ver = tp->others; ver < (const uint32_t *)end; ver++) {
	if (!tp->negotiated_version) {
	int i;

	for (i = 0; i < quic_versions_nb; i++) {
	if (ntohl(*ver) == quic_versions[i].num) {
	tp->negotiated_version = &quic_versions[i];
	break;
	}
	}
	}

	if (preferred_version && ntohl(*ver) == preferred_version->num) {
	tp->negotiated_version = preferred_version;
	goto out;
	}
	}

	out:
	*buf = end;

	return 1;
	}

	/* Decode into <p> struct a transport parameter found in <*buf> buffer with
	* <type> as type and <len> as length, depending on <server> boolean value which
	* must be set to 1 for a server (haproxy listener) or 0 for a client (connection
	* to an haproxy server).
	*/
	static int quic_transport_param_decode(struct quic_transport_params *p,
	int server, uint64_t type,
	const unsigned char **buf, size_t len)
	{
	const unsigned char end = buf + len;

	switch (type) {
	case QUIC_TP_ORIGINAL_DESTINATION_CONNECTION_ID:
	if (!server \|\| len > sizeof p->original_destination_connection_id.data)
	return 0;

	if (len)
	memcpy(p->original_destination_connection_id.data, *buf, len);
	p->original_destination_connection_id.len = len;
	*buf += len;
	p->original_destination_connection_id_present = 1;
	break;
	case QUIC_TP_INITIAL_SOURCE_CONNECTION_ID:
	if (len > sizeof p->initial_source_connection_id.data)
	return 0;

	if (len)
	memcpy(p->initial_source_connection_id.data, *buf, len);
	p->initial_source_connection_id.len = len;
	*buf += len;
	p->initial_source_connection_id_present = 1;
	break;
	case QUIC_TP_STATELESS_RESET_TOKEN:
	if (!server \|\| len != sizeof p->stateless_reset_token)
	return 0;
	memcpy(p->stateless_reset_token, *buf, len);
	*buf += len;
	p->with_stateless_reset_token = 1;
	break;
	case QUIC_TP_PREFERRED_ADDRESS:
	if (!server)
	return 0;
	if (!quic_transport_param_dec_pref_addr(&p->preferred_address, buf, *buf + len))
	return 0;
	p->with_preferred_address = 1;
	break;
	case QUIC_TP_MAX_IDLE_TIMEOUT:
	if (!quic_dec_int(&p->max_idle_timeout, buf, end))
	return 0;
	break;
	case QUIC_TP_MAX_UDP_PAYLOAD_SIZE:
	if (!quic_dec_int(&p->max_udp_payload_size, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_DATA:
	if (!quic_dec_int(&p->initial_max_data, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_LOCAL:
	if (!quic_dec_int(&p->initial_max_stream_data_bidi_local, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_REMOTE:
	if (!quic_dec_int(&p->initial_max_stream_data_bidi_remote, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_STREAM_DATA_UNI:
	if (!quic_dec_int(&p->initial_max_stream_data_uni, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_STREAMS_BIDI:
	if (!quic_dec_int(&p->initial_max_streams_bidi, buf, end))
	return 0;
	break;
	case QUIC_TP_INITIAL_MAX_STREAMS_UNI:
	if (!quic_dec_int(&p->initial_max_streams_uni, buf, end))
	return 0;
	break;
	case QUIC_TP_ACK_DELAY_EXPONENT:
	if (!quic_dec_int(&p->ack_delay_exponent, buf, end) \|\|
	p->ack_delay_exponent > QUIC_TP_ACK_DELAY_EXPONENT_LIMIT)
	return 0;
	break;
	case QUIC_TP_MAX_ACK_DELAY:
	if (!quic_dec_int(&p->max_ack_delay, buf, end) \|\|
	p->max_ack_delay > QUIC_TP_MAX_ACK_DELAY_LIMIT)
	return 0;
	break;
	case QUIC_TP_DISABLE_ACTIVE_MIGRATION:
	/* Zero-length parameter type. */
	if (len != 0)
	return 0;
	p->disable_active_migration = 1;
	break;
	case QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT:
	if (!quic_dec_int(&p->active_connection_id_limit, buf, end))
	return 0;
	break;
	case QUIC_TP_DRAFT_VERSION_INFORMATION:
	if (!quic_transport_param_dec_version_info(&p->version_information,
	buf, *buf + len, server))
	return 0;
	break;
	default:
	*buf += len;
	};

	return *buf == end;
	}

	/* Encode <type> and <len> variable length values in <buf>.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_encode_type_len(unsigned char **buf,
	const unsigned char *end,
	uint64_t type, uint64_t len)
	{
	return quic_enc_int(buf, end, type) && quic_enc_int(buf, end, len);
	}

	/* Decode variable length type and length values of a QUIC transport parameter
	* into <type> and <len> found in <*buf> buffer.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_decode_type_len(uint64_t type, uint64_t len,
	const unsigned char **buf,
	const unsigned char *end)
	{
	return quic_dec_int(type, buf, end) && quic_dec_int(len, buf, end);
	}

	/* Encode <param> bytes stream with <type> as type and <length> as length into buf.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_enc_mem(unsigned char *buf, const unsigned char end,
	uint64_t type, void *param, uint64_t length)
	{
	if (!quic_transport_param_encode_type_len(buf, end, type, length))
	return 0;

	if (end - *buf < length)
	return 0;

	if (length)
	memcpy(*buf, param, length);
	*buf += length;

	return 1;
	}

	/* Encode <val> 64-bits value as variable length integer into <buf>.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_enc_int(unsigned char **buf,
	const unsigned char *end,
	uint64_t type, uint64_t val)
	{
	size_t len;

	len = quic_int_getsize(val);

	return len && quic_transport_param_encode_type_len(buf, end, type, len) &&
	quic_enc_int(buf, end, val);
	}

	/* Returns the required length in bytes to encode <cid> QUIC connection ID. */
	static inline size_t sizeof_quic_cid(const struct tp_cid *cid)
	{
	return sizeof cid->len + cid->len;
	}

	/* Encode <addr> preferred address into <buf>.
	* Note that the IP addresses must be encoded in network byte order.
	* So ->ipv4_addr and ->ipv6_addr, which are buffers, must contained
	* values already encoded in network byte order.
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_enc_pref_addr(unsigned char **buf,
	const unsigned char *end,
	struct tp_preferred_address *addr)
	{
	uint64_t addr_len = 0;

	addr_len += sizeof addr->ipv4_port + sizeof addr->ipv4_addr;
	addr_len += sizeof addr->ipv6_port + sizeof addr->ipv6_addr;
	addr_len += sizeof_quic_cid(&addr->cid);
	addr_len += sizeof addr->stateless_reset_token;

	if (!quic_transport_param_encode_type_len(buf, end, QUIC_TP_PREFERRED_ADDRESS, addr_len))
	return 0;

	if (end - *buf < addr_len)
	return 0;

	quic_transport_param_enc_pref_addr_val(buf, end, addr);

	return 1;
	}

	/* Encode version information transport parameters with <chosen_version> as chosen
	* version.
	* Return 1 if succeeded, 0 if not.
	*/
	static int quic_transport_param_enc_version_info(unsigned char **buf,
	const unsigned char *end,
	const struct quic_version *chosen_version,
	int server)
	{
	int i;
	uint64_t tp_len;
	uint32_t ver;

	tp_len = sizeof chosen_version->num + quic_versions_nb * sizeof(uint32_t);
	if (!quic_transport_param_encode_type_len(buf, end,
	QUIC_TP_DRAFT_VERSION_INFORMATION,
	tp_len))
	return 0;

	if (end - *buf < tp_len)
	return 0;

	/* First: chosen version */
	ver = htonl(chosen_version->num);
	memcpy(*buf, &ver, sizeof ver);
	*buf += sizeof ver;
	/* For servers: all supported version, chosen included */
	for (i = 0; i < quic_versions_nb; i++) {
	ver = htonl(quic_versions[i].num);
	memcpy(*buf, &ver, sizeof ver);
	*buf += sizeof ver;
	}

	return 1;
	}

	/* Encode <p> transport parameter into <buf> depending on <server> value which
	* must be set to 1 for a server (haproxy listener) or 0 for a client
	* (connection to a haproxy server).
	* Return the number of bytes consumed if succeeded, 0 if not.
	*/
	int quic_transport_params_encode(unsigned char *buf,
	const unsigned char *end,
	struct quic_transport_params *p,
	const struct quic_version *chosen_version,
	int server)
	{
	unsigned char *head;
	unsigned char *pos;

	head = pos = buf;
	if (server) {
	if (!quic_transport_param_enc_mem(&pos, end,
	QUIC_TP_ORIGINAL_DESTINATION_CONNECTION_ID,
	p->original_destination_connection_id.data,
	p->original_destination_connection_id.len))
	return 0;

	if (p->retry_source_connection_id.len) {
	if (!quic_transport_param_enc_mem(&pos, end,
	QUIC_TP_RETRY_SOURCE_CONNECTION_ID,
	p->retry_source_connection_id.data,
	p->retry_source_connection_id.len))
	return 0;
	}

	if (p->with_stateless_reset_token &&
	!quic_transport_param_enc_mem(&pos, end, QUIC_TP_STATELESS_RESET_TOKEN,
	p->stateless_reset_token,
	sizeof p->stateless_reset_token))
	return 0;
	if (p->with_preferred_address &&
	!quic_transport_param_enc_pref_addr(&pos, end, &p->preferred_address))
	return 0;
	}

	if (!quic_transport_param_enc_mem(&pos, end,
	QUIC_TP_INITIAL_SOURCE_CONNECTION_ID,
	p->initial_source_connection_id.data,
	p->initial_source_connection_id.len))
	return 0;

	if (p->max_idle_timeout &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_IDLE_TIMEOUT, p->max_idle_timeout))
	return 0;

	/*
	* "max_packet_size" transport parameter must be transmitted only if different
	* of the default value.
	*/
	if (p->max_udp_payload_size != QUIC_TP_DFLT_MAX_UDP_PAYLOAD_SIZE &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_UDP_PAYLOAD_SIZE, p->max_udp_payload_size))
	return 0;

	if (p->initial_max_data &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_DATA, p->initial_max_data))
	return 0;

	if (p->initial_max_stream_data_bidi_local &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_LOCAL,
	p->initial_max_stream_data_bidi_local))
	return 0;

	if (p->initial_max_stream_data_bidi_remote &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_BIDI_REMOTE,
	p->initial_max_stream_data_bidi_remote))
	return 0;

	if (p->initial_max_stream_data_uni &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAM_DATA_UNI,
	p->initial_max_stream_data_uni))
	return 0;

	if (p->initial_max_streams_bidi &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAMS_BIDI,
	p->initial_max_streams_bidi))
	return 0;

	if (p->initial_max_streams_uni &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_INITIAL_MAX_STREAMS_UNI,
	p->initial_max_streams_uni))
	return 0;

	/*
	* "ack_delay_exponent" transport parameter must be transmitted only if different
	* of the default value.
	*/
	if (p->ack_delay_exponent != QUIC_TP_DFLT_ACK_DELAY_COMPONENT &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_ACK_DELAY_EXPONENT, p->ack_delay_exponent))
	return 0;

	/*
	* "max_ack_delay" transport parameter must be transmitted only if different
	* of the default value.
	*/
	if (p->max_ack_delay != QUIC_TP_DFLT_MAX_ACK_DELAY &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_MAX_ACK_DELAY, p->max_ack_delay))
	return 0;

	/* 0-length value */
	if (p->disable_active_migration &&
	!quic_transport_param_encode_type_len(&pos, end, QUIC_TP_DISABLE_ACTIVE_MIGRATION, 0))
	return 0;

	if (p->active_connection_id_limit &&
	p->active_connection_id_limit != QUIC_TP_DFLT_ACTIVE_CONNECTION_ID_LIMIT &&
	!quic_transport_param_enc_int(&pos, end, QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT,
	p->active_connection_id_limit))
	return 0;

	if (!quic_transport_param_enc_version_info(&pos, end, chosen_version, server))
	return 0;

	return pos - head;
	}

	/* Decode transport parameters found in <buf> buffer into <p>, depending on
	* <server> boolean value which must be set to 1 for a server (haproxy listener)
	* or 0 for a client (connection to a haproxy server).
	* Returns 1 if succeeded, 0 if not.
	*/
	static int quic_transport_params_decode(struct quic_transport_params *p, int server,
	const unsigned char *buf,
	const unsigned char *end)
	{
	const unsigned char *pos;
	uint64_t type, len = 0;

	pos = buf;

	while (pos != end) {
	if (!quic_transport_param_decode_type_len(&type, &len, &pos, end))
	return 0;

	if (end - pos < len)
	return 0;

	if (!quic_transport_param_decode(p, server, type, &pos, len))
	return 0;
	}

	/*
	* A server MUST send original_destination_connection_id transport parameter.
	* initial_source_connection_id must be present both for server and client.
	*/
	if ((server && !p->original_destination_connection_id_present) \|\|
	!p->initial_source_connection_id_present)
	return 0;

	return 1;
	}

	/* Store transport parameters found in <buf> buffer into <qc> QUIC connection
	* depending on <server> value which must be 1 for a server (haproxy listener)
	* or 0 for a client (connection to a haproxy server).
	* Note that peer transport parameters are stored in the TX part of the connection:
	* they are used to send packets to the peer with its transport parameters as
	* limitations.
	* Returns 1 if succeeded, 0 if not.
	*/
	int quic_transport_params_store(struct quic_conn *qc, int server,
	const unsigned char *buf,
	const unsigned char *end)
	{
	struct quic_transport_params *tx_params = &qc->tx.params;

	/* initialize peer TPs to RFC default value */
	quic_dflt_transport_params_cpy(tx_params);

	if (!quic_transport_params_decode(tx_params, server, buf, end))
	return 0;

	return 1;
	}

	/* QUIC server (or haproxy listener) only function.
	* Initialize the local transport parameters <rx_params> from <listener_params>
	* coming from configuration and Initial packet information (destination
	* connection ID, source connection ID, original destination connection ID) from
	* client token.
	* Returns 1 if succeeded, 0 if not.
	*/
	int qc_lstnr_params_init(struct quic_conn *qc,
	const struct quic_transport_params *listener_params,
	const unsigned char *stateless_reset_token,
	const unsigned char *dcid, size_t dcidlen,
	const unsigned char *scid, size_t scidlen,
	const struct quic_cid *token_odcid)
	{
	struct quic_transport_params *rx_params = &qc->rx.params;
	struct tp_cid *odcid_param = &rx_params->original_destination_connection_id;

	/* Copy the transport parameters. */
	rx_params = listener_params;
	/* Copy the stateless reset token */
	memcpy(rx_params->stateless_reset_token, stateless_reset_token,
	sizeof rx_params->stateless_reset_token);
	/* Copy original_destination_connection_id transport parameter. */
	if (token_odcid->len) {
	memcpy(odcid_param->data, token_odcid->data, token_odcid->len);
	odcid_param->len = token_odcid->len;
	/* Copy retry_source_connection_id transport parameter. */
	memcpy(rx_params->retry_source_connection_id.data, dcid, dcidlen);
	rx_params->retry_source_connection_id.len = dcidlen;
	}
	else {
	memcpy(odcid_param->data, dcid, dcidlen);
	odcid_param->len = dcidlen;
	}

	/* Copy the initial source connection ID. */
	memcpy(rx_params->initial_source_connection_id.data, scid, scidlen);
	rx_params->initial_source_connection_id.len = scidlen;
	TRACE_PROTO("\nRX(local) transp. params.", QUIC_EV_TRANSP_PARAMS, qc, rx_params);

	return 1;
	}