[lttng-tools.git] / src / bin / lttng-sessiond / ust-metadata.c

/*
 * ust-metadata.c
 *
 * LTTng-UST metadata generation
 *
 * Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#define _LGPL_SOURCE
#include <stdint.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <limits.h>
#include <unistd.h>
#include <inttypes.h>
#include <common/common.h>

#include "ust-registry.h"
#include "ust-clock.h"
#include "ust-app.h"

#ifndef max_t
#define max_t(type, a, b)	((type) ((a) > (b) ? (a) : (b)))
#endif

#define NR_CLOCK_OFFSET_SAMPLES		10

struct offset_sample {
	uint64_t offset;		/* correlation offset */
	uint64_t measure_delta;		/* lower is better */
};

static inline
int fls(unsigned int x)
{
	int r = 32;

	if (!x)
		return 0;
	if (!(x & 0xFFFF0000U)) {
		x <<= 16;
		r -= 16;
	}
	if (!(x & 0xFF000000U)) {
		x <<= 8;
		r -= 8;
	}
	if (!(x & 0xF0000000U)) {
		x <<= 4;
		r -= 4;
	}
	if (!(x & 0xC0000000U)) {
		x <<= 2;
		r -= 2;
	}
	if (!(x & 0x80000000U)) {
		x <<= 1;
		r -= 1;
	}
	return r;
}

static inline
int get_count_order(unsigned int count)
{
	int order;

	order = fls(count) - 1;
	if (count & (count - 1))
		order++;
	return order;
}

/*
 * Returns offset where to write in metadata array, or negative error value on error.
 */
static
ssize_t metadata_reserve(struct ust_registry_session *session, size_t len)
{
	size_t new_len = session->metadata_len + len;
	size_t new_alloc_len = new_len;
	size_t old_alloc_len = session->metadata_alloc_len;
	ssize_t ret;

	if (new_alloc_len > (UINT32_MAX >> 1))
		return -EINVAL;
	if ((old_alloc_len << 1) > (UINT32_MAX >> 1))
		return -EINVAL;

	if (new_alloc_len > old_alloc_len) {
		char *newptr;

		new_alloc_len =
			max_t(size_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
		newptr = realloc(session->metadata, new_alloc_len);
		if (!newptr)
			return -ENOMEM;
		session->metadata = newptr;
		/* We zero directly the memory from start of allocation. */
		memset(&session->metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len);
		session->metadata_alloc_len = new_alloc_len;
	}
	ret = session->metadata_len;
	session->metadata_len += len;
	return ret;
}

/*
 * We have exclusive access to our metadata buffer (protected by the
 * ust_lock), so we can do racy operations such as looking for
 * remaining space left in packet and write, since mutual exclusion
 * protects us from concurrent writes.
 */
static
int lttng_metadata_printf(struct ust_registry_session *session,
		const char *fmt, ...)
{
	char *str = NULL;
	size_t len;
	va_list ap;
	ssize_t offset;
	int ret;

	va_start(ap, fmt);
	ret = vasprintf(&str, fmt, ap);
	va_end(ap);
	if (ret < 0)
		return -ENOMEM;

	len = strlen(str);
	offset = metadata_reserve(session, len);
	if (offset < 0) {
		ret = offset;
		goto end;
	}
	memcpy(&session->metadata[offset], str, len);
	DBG3("Append to metadata: \"%s\"", str);
	ret = 0;

end:
	free(str);
	return ret;
}

static
int _lttng_field_statedump(struct ust_registry_session *session,
		const struct ustctl_field *field)
{
	int ret = 0;
	const char *bo_be = " byte_order = be;";
	const char *bo_le = " byte_order = le;";
	const char *bo_native = "";
	const char *bo_reverse;

	if (session->byte_order == BIG_ENDIAN)
		bo_reverse = bo_le;
	else
		bo_reverse = bo_be;

	switch (field->type.atype) {
	case ustctl_atype_integer:
		ret = lttng_metadata_printf(session,
			"		integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
			field->type.u.basic.integer.size,
			field->type.u.basic.integer.alignment,
			field->type.u.basic.integer.signedness,
			(field->type.u.basic.integer.encoding == ustctl_encode_none)
				? "none"
				: (field->type.u.basic.integer.encoding == ustctl_encode_UTF8)
					? "UTF8"
					: "ASCII",
			field->type.u.basic.integer.base,
			field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
			field->name);
		break;
	case ustctl_atype_float:
		ret = lttng_metadata_printf(session,
			"		floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
			field->type.u.basic._float.exp_dig,
			field->type.u.basic._float.mant_dig,
			field->type.u.basic._float.alignment,
			field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
			field->name);
		break;
	case ustctl_atype_enum:
		return -EINVAL;
	case ustctl_atype_array:
	{
		const struct ustctl_basic_type *elem_type;

		elem_type = &field->type.u.array.elem_type;
		ret = lttng_metadata_printf(session,
			"		integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
			elem_type->u.basic.integer.size,
			elem_type->u.basic.integer.alignment,
			elem_type->u.basic.integer.signedness,
			(elem_type->u.basic.integer.encoding == ustctl_encode_none)
				? "none"
				: (elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
					? "UTF8"
					: "ASCII",
			elem_type->u.basic.integer.base,
			elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
			field->name, field->type.u.array.length);
		break;
	}
	case ustctl_atype_sequence:
	{
		const struct ustctl_basic_type *elem_type;
		const struct ustctl_basic_type *length_type;

		elem_type = &field->type.u.sequence.elem_type;
		length_type = &field->type.u.sequence.length_type;
		ret = lttng_metadata_printf(session,
			"		integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
			length_type->u.basic.integer.size,
			(unsigned int) length_type->u.basic.integer.alignment,
			length_type->u.basic.integer.signedness,
			(length_type->u.basic.integer.encoding == ustctl_encode_none)
				? "none"
				: ((length_type->u.basic.integer.encoding == ustctl_encode_UTF8)
					? "UTF8"
					: "ASCII"),
			length_type->u.basic.integer.base,
			length_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
			field->name);
		if (ret)
			return ret;

		ret = lttng_metadata_printf(session,
			"		integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
			elem_type->u.basic.integer.size,
			(unsigned int) elem_type->u.basic.integer.alignment,
			elem_type->u.basic.integer.signedness,
			(elem_type->u.basic.integer.encoding == ustctl_encode_none)
				? "none"
				: ((elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
					? "UTF8"
					: "ASCII"),
			elem_type->u.basic.integer.base,
			elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
			field->name,
			field->name);
		break;
	}

	case ustctl_atype_string:
		/* Default encoding is UTF8 */
		ret = lttng_metadata_printf(session,
			"		string%s _%s;\n",
			field->type.u.basic.string.encoding == ustctl_encode_ASCII ?
				" { encoding = ASCII; }" : "",
			field->name);
		break;
	default:
		return -EINVAL;
	}
	return ret;
}

static
int _lttng_context_metadata_statedump(struct ust_registry_session *session,
		size_t nr_ctx_fields,
		struct ustctl_field *ctx)
{
	int ret = 0;
	int i;

	if (!ctx)
		return 0;
	for (i = 0; i < nr_ctx_fields; i++) {
		const struct ustctl_field *field = &ctx[i];

		ret = _lttng_field_statedump(session, field);
		if (ret)
			return ret;
	}
	return ret;
}

static
int _lttng_fields_metadata_statedump(struct ust_registry_session *session,
		struct ust_registry_event *event)
{
	int ret = 0;
	int i;

	for (i = 0; i < event->nr_fields; i++) {
		const struct ustctl_field *field = &event->fields[i];

		ret = _lttng_field_statedump(session, field);
		if (ret)
			return ret;
	}
	return ret;
}

/*
 * Should be called with session registry mutex held.
 */
int ust_metadata_event_statedump(struct ust_registry_session *session,
		struct ust_registry_channel *chan,
		struct ust_registry_event *event)
{
	int ret = 0;

	/* Don't dump metadata events */
	if (chan->chan_id == -1U)
		return 0;

	ret = lttng_metadata_printf(session,
		"event {\n"
		"	name = \"%s\";\n"
		"	id = %u;\n"
		"	stream_id = %u;\n",
		event->name,
		event->id,
		chan->chan_id);
	if (ret)
		goto end;

	ret = lttng_metadata_printf(session,
		"	loglevel = %d;\n",
		event->loglevel);
	if (ret)
		goto end;

	if (event->model_emf_uri) {
		ret = lttng_metadata_printf(session,
			"	model.emf.uri = \"%s\";\n",
			event->model_emf_uri);
		if (ret)
			goto end;
	}

#if 0 /* context for events not supported */
	if (event->ctx) {
		ret = lttng_metadata_printf(session,
			"	context := struct {\n");
		if (ret)
			goto end;
	}
	ret = _lttng_context_metadata_statedump(session, event->ctx);
	if (ret)
		goto end;
	if (event->ctx) {
		ret = lttng_metadata_printf(session,
			"	};\n");
		if (ret)
			goto end;
	}
#endif
	ret = lttng_metadata_printf(session,
		"	fields := struct {\n"
		);
	if (ret)
		goto end;

	ret = _lttng_fields_metadata_statedump(session, event);
	if (ret)
		goto end;

	ret = lttng_metadata_printf(session,
		"	};\n"
		"};\n\n");
	if (ret)
		goto end;
	event->metadata_dumped = 1;

end:
	return ret;
}

/*
 * Should be called with session registry mutex held.
 */
int ust_metadata_channel_statedump(struct ust_registry_session *session,
		struct ust_registry_channel *chan)
{
	int ret = 0;

	/* Don't dump metadata events */
	if (chan->chan_id == -1U)
		return 0;

	if (!chan->header_type)
		return -EINVAL;

	ret = lttng_metadata_printf(session,
		"stream {\n"
		"	id = %u;\n"
		"	event.header := %s;\n"
		"	packet.context := struct packet_context;\n",
		chan->chan_id,
		chan->header_type == USTCTL_CHANNEL_HEADER_COMPACT ?
			"struct event_header_compact" :
			"struct event_header_large");
	if (ret)
		goto end;

	if (chan->ctx_fields) {
		ret = lttng_metadata_printf(session,
			"	event.context := struct {\n");
		if (ret)
			goto end;
	}
	ret = _lttng_context_metadata_statedump(session,
		chan->nr_ctx_fields,
		chan->ctx_fields);
	if (ret)
		goto end;
	if (chan->ctx_fields) {
		ret = lttng_metadata_printf(session,
			"	};\n");
		if (ret)
			goto end;
	}

	ret = lttng_metadata_printf(session,
		"};\n\n");
	/* Flag success of metadata dump. */
	chan->metadata_dumped = 1;

end:
	return ret;
}

static
int _lttng_stream_packet_context_declare(struct ust_registry_session *session)
{
	return lttng_metadata_printf(session,
		"struct packet_context {\n"
		"	uint64_clock_monotonic_t timestamp_begin;\n"
		"	uint64_clock_monotonic_t timestamp_end;\n"
		"	uint64_t content_size;\n"
		"	uint64_t packet_size;\n"
		"	unsigned long events_discarded;\n"
		"	uint32_t cpu_id;\n"
		"};\n\n"
		);
}

/*
 * Compact header:
 * id: range: 0 - 30.
 * id 31 is reserved to indicate an extended header.
 *
 * Large header:
 * id: range: 0 - 65534.
 * id 65535 is reserved to indicate an extended header.
 */
static
int _lttng_event_header_declare(struct ust_registry_session *session)
{
	return lttng_metadata_printf(session,
	"struct event_header_compact {\n"
	"	enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
	"	variant <id> {\n"
	"		struct {\n"
	"			uint27_clock_monotonic_t timestamp;\n"
	"		} compact;\n"
	"		struct {\n"
	"			uint32_t id;\n"
	"			uint64_clock_monotonic_t timestamp;\n"
	"		} extended;\n"
	"	} v;\n"
	"} align(%u);\n"
	"\n"
	"struct event_header_large {\n"
	"	enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
	"	variant <id> {\n"
	"		struct {\n"
	"			uint32_clock_monotonic_t timestamp;\n"
	"		} compact;\n"
	"		struct {\n"
	"			uint32_t id;\n"
	"			uint64_clock_monotonic_t timestamp;\n"
	"		} extended;\n"
	"	} v;\n"
	"} align(%u);\n\n",
	session->uint32_t_alignment,
	session->uint16_t_alignment
	);
}

static
int measure_single_clock_offset(struct offset_sample *sample)
{
	uint64_t offset, monotonic[2], measure_delta, realtime;
	struct timespec rts = { 0, 0 };
	int ret;

	monotonic[0] = trace_clock_read64();
	ret = clock_gettime(CLOCK_REALTIME, &rts);
	if (ret < 0) {
		return ret;
	}
	monotonic[1] = trace_clock_read64();
	measure_delta = monotonic[1] - monotonic[0];
	if (measure_delta > sample->measure_delta) {
		/*
		 * Discard value if it took longer to read than the best
		 * sample so far.
		 */
		return 0;
	}
	offset = (monotonic[0] + monotonic[1]) >> 1;
	realtime = (uint64_t) rts.tv_sec * 1000000000ULL;
	realtime += rts.tv_nsec;
	offset = realtime - offset;
	sample->offset = offset;
	sample->measure_delta = measure_delta;
	return 0;
}

/*
 * Approximation of NTP time of day to clock monotonic correlation,
 * taken at start of trace. Keep the measurement that took the less time
 * to complete, thus removing imprecision caused by preemption.
 */
static
uint64_t measure_clock_offset(void)
{
	int i;
	struct offset_sample offset_best_sample = {
		.offset = 0,
		.measure_delta = UINT64_MAX,
	};

	for (i = 0; i < NR_CLOCK_OFFSET_SAMPLES; i++) {
		if (measure_single_clock_offset(&offset_best_sample)) {
			return 0;
		}
	}
	return offset_best_sample.offset;
}

/*
 * Should be called with session registry mutex held.
 */
int ust_metadata_session_statedump(struct ust_registry_session *session,
		struct ust_app *app,
		uint32_t major,
		uint32_t minor)
{
	unsigned char *uuid_c;
	char uuid_s[UUID_STR_LEN],
		clock_uuid_s[UUID_STR_LEN];
	int ret = 0;
	char hostname[HOST_NAME_MAX];

	assert(session);

	uuid_c = session->uuid;

	snprintf(uuid_s, sizeof(uuid_s),
		"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
		uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
		uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
		uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
		uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);

	ret = lttng_metadata_printf(session,
		"typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
		"typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
		"typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
		"typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
		"typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
		"typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
		"typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
		"\n"
		"trace {\n"
		"	major = %u;\n"
		"	minor = %u;\n"
		"	uuid = \"%s\";\n"
		"	byte_order = %s;\n"
		"	packet.header := struct {\n"
		"		uint32_t magic;\n"
		"		uint8_t  uuid[16];\n"
		"		uint32_t stream_id;\n"
		"	};\n"
		"};\n\n",
		session->uint8_t_alignment,
		session->uint16_t_alignment,
		session->uint32_t_alignment,
		session->uint64_t_alignment,
		session->bits_per_long,
		session->long_alignment,
		CTF_SPEC_MAJOR,
		CTF_SPEC_MINOR,
		uuid_s,
		session->byte_order == BIG_ENDIAN ? "be" : "le"
		);
	if (ret)
		goto end;

	/* ignore error, just use empty string if error. */
	hostname[0] = '\0';
	ret = gethostname(hostname, sizeof(hostname));
	if (ret && errno == ENAMETOOLONG)
		hostname[HOST_NAME_MAX - 1] = '\0';
	ret = lttng_metadata_printf(session,
		"env {\n"
		"	hostname = \"%s\";\n"
		"	domain = \"ust\";\n"
		"	tracer_name = \"lttng-ust\";\n"
		"	tracer_major = %u;\n"
		"	tracer_minor = %u;\n",
		hostname,
		major,
		minor
		);
	if (ret)
		goto end;

	/*
	 * If per-application registry, we can output extra information
	 * about the application.
	 */
	if (app) {
		ret = lttng_metadata_printf(session,
			"	tracer_patchlevel = %u;\n"
			"	vpid = %d;\n"
			"	procname = \"%s\";\n",
			app->version.patchlevel,
			(int) app->pid,
			app->name
			);
		if (ret)
			goto end;
	}

	ret = lttng_metadata_printf(session,
		"};\n\n"
		);
	if (ret)
		goto end;


	ret = lttng_metadata_printf(session,
		"clock {\n"
		"	name = %s;\n",
		"monotonic"
		);
	if (ret)
		goto end;

	if (!trace_clock_uuid(clock_uuid_s)) {
		ret = lttng_metadata_printf(session,
			"	uuid = \"%s\";\n",
			clock_uuid_s
			);
		if (ret)
			goto end;
	}

	ret = lttng_metadata_printf(session,
		"	description = \"Monotonic Clock\";\n"
		"	freq = %" PRIu64 "; /* Frequency, in Hz */\n"
		"	/* clock value offset from Epoch is: offset * (1/freq) */\n"
		"	offset = %" PRIu64 ";\n"
		"};\n\n",
		trace_clock_freq(),
		measure_clock_offset()
		);
	if (ret)
		goto end;

	ret = lttng_metadata_printf(session,
		"typealias integer {\n"
		"	size = 27; align = 1; signed = false;\n"
		"	map = clock.monotonic.value;\n"
		"} := uint27_clock_monotonic_t;\n"
		"\n"
		"typealias integer {\n"
		"	size = 32; align = %u; signed = false;\n"
		"	map = clock.monotonic.value;\n"
		"} := uint32_clock_monotonic_t;\n"
		"\n"
		"typealias integer {\n"
		"	size = 64; align = %u; signed = false;\n"
		"	map = clock.monotonic.value;\n"
		"} := uint64_clock_monotonic_t;\n\n",
		session->uint32_t_alignment,
		session->uint64_t_alignment
		);
	if (ret)
		goto end;

	ret = _lttng_stream_packet_context_declare(session);
	if (ret)
		goto end;

	ret = _lttng_event_header_declare(session);
	if (ret)
		goto end;

end:
	return ret;
}
Commit	Line	Data
d0b96690 DG	1	/*
	2	* ust-metadata.c
	3	*
	4	* LTTng-UST metadata generation
	5	*
	6	* Copyright (C) 2010-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License, version 2 only,
	10	* as published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along
	18	* with this program; if not, write to the Free Software Foundation, Inc.,
	19	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	20	*/
	21
	22	#define _GNU_SOURCE
6c1c0768	23	#define _LGPL_SOURCE
d0b96690 DG	24	#include <stdint.h>
	25	#include <string.h>
	26	#include <stdarg.h>
	27	#include <stdio.h>
	28	#include <limits.h>
	29	#include <unistd.h>
	30	#include <inttypes.h>
	31	#include <common/common.h>
	32
	33	#include "ust-registry.h"
	34	#include "ust-clock.h"
	35	#include "ust-app.h"
	36
	37	#ifndef max_t
	38	#define max_t(type, a, b) ((type) ((a) > (b) ? (a) : (b)))
	39	#endif
	40
8c645bb0 MD	41	#define NR_CLOCK_OFFSET_SAMPLES 10
	42
	43	struct offset_sample {
	44	uint64_t offset; /* correlation offset */
	45	uint64_t measure_delta; /* lower is better */
	46	};
	47
d0b96690 DG	48	static inline
	49	int fls(unsigned int x)
	50	{
	51	int r = 32;
	52
	53	if (!x)
	54	return 0;
	55	if (!(x & 0xFFFF0000U)) {
	56	x <<= 16;
	57	r -= 16;
	58	}
	59	if (!(x & 0xFF000000U)) {
	60	x <<= 8;
	61	r -= 8;
	62	}
	63	if (!(x & 0xF0000000U)) {
	64	x <<= 4;
	65	r -= 4;
	66	}
	67	if (!(x & 0xC0000000U)) {
	68	x <<= 2;
	69	r -= 2;
	70	}
	71	if (!(x & 0x80000000U)) {
	72	x <<= 1;
	73	r -= 1;
	74	}
	75	return r;
	76	}
	77
	78	static inline
	79	int get_count_order(unsigned int count)
	80	{
	81	int order;
	82
	83	order = fls(count) - 1;
	84	if (count & (count - 1))
	85	order++;
	86	return order;
	87	}
	88
	89	/*
	90	* Returns offset where to write in metadata array, or negative error value on error.
	91	*/
	92	static
	93	ssize_t metadata_reserve(struct ust_registry_session *session, size_t len)
	94	{
	95	size_t new_len = session->metadata_len + len;
	96	size_t new_alloc_len = new_len;
	97	size_t old_alloc_len = session->metadata_alloc_len;
	98	ssize_t ret;
	99
	100	if (new_alloc_len > (UINT32_MAX >> 1))
	101	return -EINVAL;
	102	if ((old_alloc_len << 1) > (UINT32_MAX >> 1))
	103	return -EINVAL;
	104
	105	if (new_alloc_len > old_alloc_len) {
	106	char *newptr;
	107
	108	new_alloc_len =
	109	max_t(size_t, 1U << get_count_order(new_alloc_len), old_alloc_len << 1);
	110	newptr = realloc(session->metadata, new_alloc_len);
	111	if (!newptr)
112	return -ENOMEM;
113	session->metadata = newptr;
114	/* We zero directly the memory from start of allocation. */
115	memset(&session->metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len);
116	session->metadata_alloc_len = new_alloc_len;
117	}
118	ret = session->metadata_len;
119	session->metadata_len += len;
120	return ret;
121	}
122
123	/*
124	* We have exclusive access to our metadata buffer (protected by the
125	* ust_lock), so we can do racy operations such as looking for
126	* remaining space left in packet and write, since mutual exclusion
127	* protects us from concurrent writes.
128	*/
129	static
130	int lttng_metadata_printf(struct ust_registry_session *session,
131	const char *fmt, ...)
132	{
133	char *str = NULL;
134	size_t len;
135	va_list ap;
136	ssize_t offset;
137	int ret;
138
139	va_start(ap, fmt);
140	ret = vasprintf(&str, fmt, ap);
141	va_end(ap);
142	if (ret < 0)
143	return -ENOMEM;
144
145	len = strlen(str);
146	offset = metadata_reserve(session, len);
147	if (offset < 0) {
148	ret = offset;
149	goto end;
150	}
151	memcpy(&session->metadata[offset], str, len);
152	DBG3("Append to metadata: \"%s\"", str);
153	ret = 0;
154
155	end:
156	free(str);
157	return ret;
158	}
159
160	static
161	int _lttng_field_statedump(struct ust_registry_session *session,
162	const struct ustctl_field *field)
163	{
164	int ret = 0;
165	const char *bo_be = " byte_order = be;";
166	const char *bo_le = " byte_order = le;";
167	const char *bo_native = "";
168	const char *bo_reverse;
169
170	if (session->byte_order == BIG_ENDIAN)
171	bo_reverse = bo_le;
172	else
173	bo_reverse = bo_be;
174
175	switch (field->type.atype) {
176	case ustctl_atype_integer:
177	ret = lttng_metadata_printf(session,
178	" integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n",
179	field->type.u.basic.integer.size,
180	field->type.u.basic.integer.alignment,
181	field->type.u.basic.integer.signedness,
182	(field->type.u.basic.integer.encoding == ustctl_encode_none)
183	? "none"
184	: (field->type.u.basic.integer.encoding == ustctl_encode_UTF8)
185	? "UTF8"
186	: "ASCII",
187	field->type.u.basic.integer.base,
188	field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
189	field->name);
190	break;
191	case ustctl_atype_float:
192	ret = lttng_metadata_printf(session,
193	" floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n",
194	field->type.u.basic._float.exp_dig,
195	field->type.u.basic._float.mant_dig,
196	field->type.u.basic._float.alignment,
197	field->type.u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
198	field->name);
199	break;
200	case ustctl_atype_enum:
201	return -EINVAL;
202	case ustctl_atype_array:
203	{
204	const struct ustctl_basic_type *elem_type;
205
206	elem_type = &field->type.u.array.elem_type;
207	ret = lttng_metadata_printf(session,
208	" integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n",
209	elem_type->u.basic.integer.size,
210	elem_type->u.basic.integer.alignment,
211	elem_type->u.basic.integer.signedness,
212	(elem_type->u.basic.integer.encoding == ustctl_encode_none)
213	? "none"
214	: (elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
215	? "UTF8"
216	: "ASCII",
217	elem_type->u.basic.integer.base,
218	elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
219	field->name, field->type.u.array.length);
220	break;
221	}
222	case ustctl_atype_sequence:
223	{
224	const struct ustctl_basic_type *elem_type;
225	const struct ustctl_basic_type *length_type;
226
227	elem_type = &field->type.u.sequence.elem_type;
228	length_type = &field->type.u.sequence.length_type;
229	ret = lttng_metadata_printf(session,
230	" integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n",
231	length_type->u.basic.integer.size,
232	(unsigned int) length_type->u.basic.integer.alignment,
233	length_type->u.basic.integer.signedness,
234	(length_type->u.basic.integer.encoding == ustctl_encode_none)
235	? "none"
236	: ((length_type->u.basic.integer.encoding == ustctl_encode_UTF8)
237	? "UTF8"
238	: "ASCII"),
239	length_type->u.basic.integer.base,
240	length_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
241	field->name);
242	if (ret)
243	return ret;
244
245	ret = lttng_metadata_printf(session,
246	" integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n",
247	elem_type->u.basic.integer.size,
248	(unsigned int) elem_type->u.basic.integer.alignment,
249	elem_type->u.basic.integer.signedness,
250	(elem_type->u.basic.integer.encoding == ustctl_encode_none)
251	? "none"
252	: ((elem_type->u.basic.integer.encoding == ustctl_encode_UTF8)
253	? "UTF8"
254	: "ASCII"),
255	elem_type->u.basic.integer.base,
256	elem_type->u.basic.integer.reverse_byte_order ? bo_reverse : bo_native,
257	field->name,
258	field->name);
259	break;
260	}
261
262	case ustctl_atype_string:
263	/* Default encoding is UTF8 */
264	ret = lttng_metadata_printf(session,
265	" string%s _%s;\n",
266	field->type.u.basic.string.encoding == ustctl_encode_ASCII ?
267	" { encoding = ASCII; }" : "",
268	field->name);
269	break;
270	default:
271	return -EINVAL;
272	}
273	return ret;
274	}
275
276	static
277	int _lttng_context_metadata_statedump(struct ust_registry_session *session,
278	size_t nr_ctx_fields,
279	struct ustctl_field *ctx)
280	{
281	int ret = 0;
282	int i;
283
284	if (!ctx)
285	return 0;
286	for (i = 0; i < nr_ctx_fields; i++) {
287	const struct ustctl_field *field = &ctx[i];
288
289	ret = _lttng_field_statedump(session, field);
290	if (ret)
291	return ret;
292	}
293	return ret;
294	}
295
296	static
297	int _lttng_fields_metadata_statedump(struct ust_registry_session *session,
298	struct ust_registry_event *event)
299	{
300	int ret = 0;
301	int i;
302
303	for (i = 0; i < event->nr_fields; i++) {
304	const struct ustctl_field *field = &event->fields[i];
305
306	ret = _lttng_field_statedump(session, field);
307	if (ret)
308	return ret;
309	}
310	return ret;
311	}
312
313	/*
314	* Should be called with session registry mutex held.
315	*/
316	int ust_metadata_event_statedump(struct ust_registry_session *session,
317	struct ust_registry_channel *chan,
318	struct ust_registry_event *event)
319	{
320	int ret = 0;
321
322	/* Don't dump metadata events */
323	if (chan->chan_id == -1U)
324	return 0;
325
326	ret = lttng_metadata_printf(session,
327	"event {\n"
328	" name = \"%s\";\n"
329	" id = %u;\n"
330	" stream_id = %u;\n",
331	event->name,
332	event->id,
333	chan->chan_id);
334	if (ret)
335	goto end;
336
337	ret = lttng_metadata_printf(session,
338	" loglevel = %d;\n",
339	event->loglevel);
340	if (ret)
341	goto end;
342
343	if (event->model_emf_uri) {
344	ret = lttng_metadata_printf(session,
345	" model.emf.uri = \"%s\";\n",
346	event->model_emf_uri);
347	if (ret)
348	goto end;
349	}
350
351	#if 0 /* context for events not supported */
352	if (event->ctx) {
353	ret = lttng_metadata_printf(session,
354	" context := struct {\n");
355	if (ret)
356	goto end;
357	}
358	ret = _lttng_context_metadata_statedump(session, event->ctx);
359	if (ret)
360	goto end;
361	if (event->ctx) {
362	ret = lttng_metadata_printf(session,
363	" };\n");
364	if (ret)
365	goto end;
366	}
367	#endif
368	ret = lttng_metadata_printf(session,
369	" fields := struct {\n"
370	);
371	if (ret)
372	goto end;
373
374	ret = _lttng_fields_metadata_statedump(session, event);
375	if (ret)
376	goto end;
377
378	ret = lttng_metadata_printf(session,
379	" };\n"
380	"};\n\n");
381	if (ret)
382	goto end;
7972aab2	383	event->metadata_dumped = 1;
d0b96690 DG	384
	385	end:
	386	return ret;
	387	}
	388
	389	/*
	390	* Should be called with session registry mutex held.
	391	*/
	392	int ust_metadata_channel_statedump(struct ust_registry_session *session,
	393	struct ust_registry_channel *chan)
	394	{
	395	int ret = 0;
	396
	397	/* Don't dump metadata events */
	398	if (chan->chan_id == -1U)
	399	return 0;
	400
	401	if (!chan->header_type)
	402	return -EINVAL;
	403
	404	ret = lttng_metadata_printf(session,
	405	"stream {\n"
	406	" id = %u;\n"
	407	" event.header := %s;\n"
	408	" packet.context := struct packet_context;\n",
	409	chan->chan_id,
	410	chan->header_type == USTCTL_CHANNEL_HEADER_COMPACT ?
	411	"struct event_header_compact" :
	412	"struct event_header_large");
	413	if (ret)
	414	goto end;
	415
	416	if (chan->ctx_fields) {
	417	ret = lttng_metadata_printf(session,
	418	" event.context := struct {\n");
	419	if (ret)
	420	goto end;
	421	}
	422	ret = _lttng_context_metadata_statedump(session,
	423	chan->nr_ctx_fields,
	424	chan->ctx_fields);
	425	if (ret)
	426	goto end;
	427	if (chan->ctx_fields) {
	428	ret = lttng_metadata_printf(session,
	429	" };\n");
	430	if (ret)
	431	goto end;
	432	}
	433
	434	ret = lttng_metadata_printf(session,
	435	"};\n\n");
7972aab2 DG	436	/* Flag success of metadata dump. */
7972aab2 DG	437	chan->metadata_dumped = 1;
d0b96690 DG	438
	439	end:
	440	return ret;
	441	}
	442
	443	static
	444	int _lttng_stream_packet_context_declare(struct ust_registry_session *session)
	445	{
	446	return lttng_metadata_printf(session,
	447	"struct packet_context {\n"
	448	" uint64_clock_monotonic_t timestamp_begin;\n"
	449	" uint64_clock_monotonic_t timestamp_end;\n"
	450	" uint64_t content_size;\n"
	451	" uint64_t packet_size;\n"
	452	" unsigned long events_discarded;\n"
	453	" uint32_t cpu_id;\n"
	454	"};\n\n"
	455	);
	456	}
	457
	458	/*
	459	* Compact header:
	460	* id: range: 0 - 30.
	461	* id 31 is reserved to indicate an extended header.
	462	*
	463	* Large header:
	464	* id: range: 0 - 65534.
	465	* id 65535 is reserved to indicate an extended header.
	466	*/
	467	static
	468	int _lttng_event_header_declare(struct ust_registry_session *session)
	469	{
	470	return lttng_metadata_printf(session,
	471	"struct event_header_compact {\n"
	472	" enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n"
	473	" variant <id> {\n"
	474	" struct {\n"
	475	" uint27_clock_monotonic_t timestamp;\n"
	476	" } compact;\n"
	477	" struct {\n"
	478	" uint32_t id;\n"
	479	" uint64_clock_monotonic_t timestamp;\n"
	480	" } extended;\n"
	481	" } v;\n"
	482	"} align(%u);\n"
	483	"\n"
	484	"struct event_header_large {\n"
	485	" enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n"
	486	" variant <id> {\n"
	487	" struct {\n"
	488	" uint32_clock_monotonic_t timestamp;\n"
	489	" } compact;\n"
	490	" struct {\n"
	491	" uint32_t id;\n"
	492	" uint64_clock_monotonic_t timestamp;\n"
	493	" } extended;\n"
	494	" } v;\n"
	495	"} align(%u);\n\n",
	496	session->uint32_t_alignment,
	497	session->uint16_t_alignment
	498	);
	499	}
	500
d0b96690	501	static
8c645bb0	502	int measure_single_clock_offset(struct offset_sample *sample)
d0b96690	503	{
8c645bb0	504	uint64_t offset, monotonic[2], measure_delta, realtime;
d0b96690 DG	505	struct timespec rts = { 0, 0 };
	506	int ret;
	507
	508	monotonic[0] = trace_clock_read64();
	509	ret = clock_gettime(CLOCK_REALTIME, &rts);
8c645bb0 MD	510	if (ret < 0) {
	511	return ret;
	512	}
d0b96690	513	monotonic[1] = trace_clock_read64();
8c645bb0 MD	514	measure_delta = monotonic[1] - monotonic[0];
	515	if (measure_delta > sample->measure_delta) {
	516	/*
	517	* Discard value if it took longer to read than the best
	518	* sample so far.
	519	*/
	520	return 0;
	521	}
d0b96690 DG	522	offset = (monotonic[0] + monotonic[1]) >> 1;
	523	realtime = (uint64_t) rts.tv_sec * 1000000000ULL;
	524	realtime += rts.tv_nsec;
	525	offset = realtime - offset;
8c645bb0 MD	526	sample->offset = offset;
	527	sample->measure_delta = measure_delta;
	528	return 0;
d0b96690 DG	529	}
d0b96690 DG	530
8c645bb0 MD	531	/*
	532	* Approximation of NTP time of day to clock monotonic correlation,
	533	* taken at start of trace. Keep the measurement that took the less time
	534	* to complete, thus removing imprecision caused by preemption.
	535	*/
	536	static
	537	uint64_t measure_clock_offset(void)
	538	{
	539	int i;
	540	struct offset_sample offset_best_sample = {
	541	.offset = 0,
	542	.measure_delta = UINT64_MAX,
	543	};
	544
	545	for (i = 0; i < NR_CLOCK_OFFSET_SAMPLES; i++) {
	546	if (measure_single_clock_offset(&offset_best_sample)) {
	547	return 0;
	548	}
	549	}
	550	return offset_best_sample.offset;
	551	}
d0b96690 DG	552
	553	/*
	554	* Should be called with session registry mutex held.
	555	*/
	556	int ust_metadata_session_statedump(struct ust_registry_session *session,
af6142cf MD	557	struct ust_app *app,
	558	uint32_t major,
	559	uint32_t minor)
d0b96690 DG	560	{
	561	unsigned char *uuid_c;
	562	char uuid_s[UUID_STR_LEN],
	563	clock_uuid_s[UUID_STR_LEN];
	564	int ret = 0;
	565	char hostname[HOST_NAME_MAX];
	566
7972aab2	567	assert(session);
7972aab2	568
d0b96690 DG	569	uuid_c = session->uuid;
	570
	571	snprintf(uuid_s, sizeof(uuid_s),
	572	"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
	573	uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3],
	574	uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7],
	575	uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11],
	576	uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]);
	577
	578	ret = lttng_metadata_printf(session,
	579	"typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n"
	580	"typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n"
	581	"typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n"
	582	"typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n"
	583	"typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n"
	584	"typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n"
	585	"typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n"
	586	"\n"
	587	"trace {\n"
	588	" major = %u;\n"
	589	" minor = %u;\n"
	590	" uuid = \"%s\";\n"
	591	" byte_order = %s;\n"
	592	" packet.header := struct {\n"
	593	" uint32_t magic;\n"
	594	" uint8_t uuid[16];\n"
	595	" uint32_t stream_id;\n"
	596	" };\n"
	597	"};\n\n",
	598	session->uint8_t_alignment,
	599	session->uint16_t_alignment,
	600	session->uint32_t_alignment,
	601	session->uint64_t_alignment,
	602	session->bits_per_long,
	603	session->long_alignment,
	604	CTF_SPEC_MAJOR,
	605	CTF_SPEC_MINOR,
	606	uuid_s,
	607	session->byte_order == BIG_ENDIAN ? "be" : "le"
	608	);
	609	if (ret)
	610	goto end;
	611
	612	/* ignore error, just use empty string if error. */
	613	hostname[0] = '\0';
	614	ret = gethostname(hostname, sizeof(hostname));
	615	if (ret && errno == ENAMETOOLONG)
	616	hostname[HOST_NAME_MAX - 1] = '\0';
	617	ret = lttng_metadata_printf(session,
	618	"env {\n"
	619	" hostname = \"%s\";\n"
	620	" domain = \"ust\";\n"
	621	" tracer_name = \"lttng-ust\";\n"
	622	" tracer_major = %u;\n"
af6142cf	623	" tracer_minor = %u;\n",
d0b96690	624	hostname,
af6142cf MD	625	major,
af6142cf MD	626	minor
d0b96690 DG	627	);
	628	if (ret)
	629	goto end;
	630
	631	/*
	632	* If per-application registry, we can output extra information
	633	* about the application.
	634	*/
	635	if (app) {
	636	ret = lttng_metadata_printf(session,
af6142cf	637	" tracer_patchlevel = %u;\n"
d0b96690	638	" vpid = %d;\n"
d88aee68	639	" procname = \"%s\";\n",
af6142cf	640	app->version.patchlevel,
d0b96690 DG	641	(int) app->pid,
	642	app->name
	643	);
	644	if (ret)
	645	goto end;
	646	}
	647
	648	ret = lttng_metadata_printf(session,
	649	"};\n\n"
	650	);
	651	if (ret)
	652	goto end;
	653
	654
	655	ret = lttng_metadata_printf(session,
	656	"clock {\n"
	657	" name = %s;\n",
	658	"monotonic"
	659	);
	660	if (ret)
	661	goto end;
	662
	663	if (!trace_clock_uuid(clock_uuid_s)) {
	664	ret = lttng_metadata_printf(session,
	665	" uuid = \"%s\";\n",
	666	clock_uuid_s
	667	);
	668	if (ret)
	669	goto end;
	670	}
	671
	672	ret = lttng_metadata_printf(session,
	673	" description = \"Monotonic Clock\";\n"
	674	" freq = %" PRIu64 "; /* Frequency, in Hz */\n"
	675	" /* clock value offset from Epoch is: offset * (1/freq) */\n"
	676	" offset = %" PRIu64 ";\n"
	677	"};\n\n",
	678	trace_clock_freq(),
	679	measure_clock_offset()
	680	);
	681	if (ret)
	682	goto end;
	683
	684	ret = lttng_metadata_printf(session,
	685	"typealias integer {\n"
	686	" size = 27; align = 1; signed = false;\n"
	687	" map = clock.monotonic.value;\n"
	688	"} := uint27_clock_monotonic_t;\n"
	689	"\n"
	690	"typealias integer {\n"
	691	" size = 32; align = %u; signed = false;\n"
	692	" map = clock.monotonic.value;\n"
	693	"} := uint32_clock_monotonic_t;\n"
	694	"\n"
	695	"typealias integer {\n"
	696	" size = 64; align = %u; signed = false;\n"
	697	" map = clock.monotonic.value;\n"
	698	"} := uint64_clock_monotonic_t;\n\n",
	699	session->uint32_t_alignment,
	700	session->uint64_t_alignment
	701	);
	702	if (ret)
	703	goto end;
	704
705	ret = _lttng_stream_packet_context_declare(session);
706	if (ret)
707	goto end;
708
709	ret = _lttng_event_header_declare(session);
710	if (ret)
711	goto end;
712
713	end:
714	return ret;
715	}