X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fevent-rule%2Fkernel-tracepoint.cpp;fp=src%2Fcommon%2Fevent-rule%2Fkernel-tracepoint.cpp;h=cff3048f30995b7dff94f436c0a0312fa50f3f04;hp=0000000000000000000000000000000000000000;hb=a6bc4ca9d659caf016ef932fcd944029737ac57c;hpb=97535efaa975ca52bf02c2d5e76351bfd2e3defa

diff --git a/src/common/event-rule/kernel-tracepoint.cpp b/src/common/event-rule/kernel-tracepoint.cpp
new file mode 100644
index 000000000..cff3048f3
--- /dev/null
+++ b/src/common/event-rule/kernel-tracepoint.cpp
@@ -0,0 +1,586 @@
+/*
+ * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <common/credentials.h>
+#include <common/error.h>
+#include <common/hashtable/hashtable.h>
+#include <common/hashtable/utils.h>
+#include <common/macros.h>
+#include <common/mi-lttng.h>
+#include <common/optional.h>
+#include <common/payload-view.h>
+#include <common/payload.h>
+#include <common/runas.h>
+#include <common/string-utils/string-utils.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/kernel-tracepoint-internal.h>
+#include <lttng/event.h>
+
+#define IS_KERNEL_TRACEPOINT_EVENT_RULE(rule) \
+	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_TRACEPOINT)
+
+static void lttng_event_rule_kernel_tracepoint_destroy(struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+
+	if (rule == NULL) {
+		return;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+
+	free(tracepoint->pattern);
+	free(tracepoint->filter_expression);
+	free(tracepoint->internal_filter.filter);
+	free(tracepoint->internal_filter.bytecode);
+	free(tracepoint);
+}
+
+static bool lttng_event_rule_kernel_tracepoint_validate(
+		const struct lttng_event_rule *rule)
+{
+	bool valid = false;
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+
+	if (!rule) {
+		goto end;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+
+	/* Required field. */
+	if (!tracepoint->pattern) {
+		ERR("Invalid kernel tracepoint event rule: a pattern must be set.");
+		goto end;
+	}
+
+	valid = true;
+end:
+	return valid;
+}
+
+static int lttng_event_rule_kernel_tracepoint_serialize(
+		const struct lttng_event_rule *rule,
+		struct lttng_payload *payload)
+{
+	int ret;
+	size_t pattern_len, filter_expression_len;
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	struct lttng_event_rule_kernel_tracepoint_comm tracepoint_comm;
+
+	if (!rule || !IS_KERNEL_TRACEPOINT_EVENT_RULE(rule)) {
+		ret = -1;
+		goto end;
+	}
+
+	DBG("Serializing kernel tracepoint event rule.");
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+
+	pattern_len = strlen(tracepoint->pattern) + 1;
+
+	if (tracepoint->filter_expression != NULL) {
+		filter_expression_len =
+				strlen(tracepoint->filter_expression) + 1;
+	} else {
+		filter_expression_len = 0;
+	}
+
+	tracepoint_comm.pattern_len = pattern_len;
+	tracepoint_comm.filter_expression_len = filter_expression_len;
+
+	ret = lttng_dynamic_buffer_append(&payload->buffer, &tracepoint_comm,
+			sizeof(tracepoint_comm));
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_dynamic_buffer_append(
+			&payload->buffer, tracepoint->pattern, pattern_len);
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_dynamic_buffer_append(&payload->buffer, tracepoint->filter_expression,
+			filter_expression_len);
+	if (ret) {
+		goto end;
+	}
+
+end:
+	return ret;
+}
+
+static bool lttng_event_rule_kernel_tracepoint_is_equal(
+		const struct lttng_event_rule *_a,
+		const struct lttng_event_rule *_b)
+{
+	bool is_equal = false;
+	struct lttng_event_rule_kernel_tracepoint *a, *b;
+
+	a = container_of(_a, struct lttng_event_rule_kernel_tracepoint, parent);
+	b = container_of(_b, struct lttng_event_rule_kernel_tracepoint, parent);
+
+	if (!!a->filter_expression != !!b->filter_expression) {
+		goto end;
+	}
+
+	/* Long check. */
+	LTTNG_ASSERT(a->pattern);
+	LTTNG_ASSERT(b->pattern);
+	if (strcmp(a->pattern, b->pattern)) {
+		goto end;
+	}
+
+	if (a->filter_expression && b->filter_expression) {
+		if (strcmp(a->filter_expression, b->filter_expression)) {
+			goto end;
+		}
+	} else if (!!a->filter_expression != !!b->filter_expression) {
+		/* One is set; not the other. */
+		goto end;
+	}
+
+	is_equal = true;
+end:
+	return is_equal;
+}
+
+static enum lttng_error_code
+lttng_event_rule_kernel_tracepoint_generate_filter_bytecode(
+		struct lttng_event_rule *rule,
+		const struct lttng_credentials *creds)
+{
+	int ret;
+	enum lttng_error_code ret_code;
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	enum lttng_event_rule_status status;
+	const char *filter;
+	struct lttng_bytecode *bytecode = NULL;
+
+	LTTNG_ASSERT(rule);
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+
+	status = lttng_event_rule_kernel_tracepoint_get_filter(rule, &filter);
+	if (status == LTTNG_EVENT_RULE_STATUS_UNSET) {
+		filter = NULL;
+	} else if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+		ret_code = LTTNG_ERR_FILTER_INVAL;
+		goto end;
+	}
+
+	if (filter && filter[0] == '\0') {
+		ret_code = LTTNG_ERR_FILTER_INVAL;
+		goto error;
+	}
+
+	if (filter) {
+		tracepoint->internal_filter.filter = strdup(filter);
+		if (tracepoint->internal_filter.filter == NULL) {
+			ret_code = LTTNG_ERR_NOMEM;
+			goto error;
+		}
+	} else {
+		tracepoint->internal_filter.filter = NULL;
+	}
+
+	if (tracepoint->internal_filter.filter == NULL) {
+		ret_code = LTTNG_OK;
+		goto end;
+	}
+
+	ret = run_as_generate_filter_bytecode(
+			tracepoint->internal_filter.filter, creds,
+			&bytecode);
+	if (ret) {
+		ret_code = LTTNG_ERR_FILTER_INVAL;
+		goto end;
+	}
+
+	tracepoint->internal_filter.bytecode = bytecode;
+	bytecode = NULL;
+	ret_code = LTTNG_OK;
+
+error:
+end:
+	free(bytecode);
+	return ret_code;
+}
+
+static const char *lttng_event_rule_kernel_tracepoint_get_internal_filter(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+
+	LTTNG_ASSERT(rule);
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	return tracepoint->internal_filter.filter;
+}
+
+static const struct lttng_bytecode *
+lttng_event_rule_kernel_tracepoint_get_internal_filter_bytecode(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+
+	LTTNG_ASSERT(rule);
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	return tracepoint->internal_filter.bytecode;
+}
+
+static enum lttng_event_rule_generate_exclusions_status
+lttng_event_rule_kernel_tracepoint_generate_exclusions(
+		const struct lttng_event_rule *rule,
+		struct lttng_event_exclusion **_exclusions)
+{
+	/* Unsupported. */
+	*_exclusions = NULL;
+	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
+}
+
+static unsigned long lttng_event_rule_kernel_tracepoint_hash(
+		const struct lttng_event_rule *rule)
+{
+	unsigned long hash;
+	struct lttng_event_rule_kernel_tracepoint *tp_rule =
+			container_of(rule, typeof(*tp_rule), parent);
+
+	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_TRACEPOINT,
+			lttng_ht_seed);
+	hash ^= hash_key_str(tp_rule->pattern, lttng_ht_seed);
+
+	if (tp_rule->filter_expression) {
+		hash ^= hash_key_str(tp_rule->filter_expression, lttng_ht_seed);
+	}
+
+	return hash;
+}
+
+static enum lttng_error_code lttng_event_rule_kernel_tracepoint_mi_serialize(
+		const struct lttng_event_rule *rule, struct mi_writer *writer)
+{
+	int ret;
+	enum lttng_error_code ret_code;
+	enum lttng_event_rule_status status;
+	const char *filter = NULL;
+	const char *name_pattern = NULL;
+
+	LTTNG_ASSERT(rule);
+	LTTNG_ASSERT(writer);
+	LTTNG_ASSERT(IS_KERNEL_TRACEPOINT_EVENT_RULE(rule));
+
+	status = lttng_event_rule_kernel_tracepoint_get_name_pattern(
+			rule, &name_pattern);
+	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK);
+	LTTNG_ASSERT(name_pattern);
+
+	status = lttng_event_rule_kernel_tracepoint_get_filter(rule, &filter);
+	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK ||
+			status == LTTNG_EVENT_RULE_STATUS_UNSET);
+
+	/* Open event rule kernel tracepoint element. */
+	ret = mi_lttng_writer_open_element(
+			writer, mi_lttng_element_event_rule_kernel_tracepoint);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Name pattern. */
+	ret = mi_lttng_writer_write_element_string(writer,
+			mi_lttng_element_event_rule_name_pattern, name_pattern);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Filter. */
+	if (filter != NULL) {
+		ret = mi_lttng_writer_write_element_string(writer,
+				mi_lttng_element_event_rule_filter_expression,
+				filter);
+		if (ret) {
+			goto mi_error;
+		}
+	}
+
+	/* Close event rule kernel tracepoint element. */
+	ret = mi_lttng_writer_close_element(writer);
+	if (ret) {
+		goto mi_error;
+	}
+
+	ret_code = LTTNG_OK;
+	goto end;
+
+mi_error:
+	ret_code = LTTNG_ERR_MI_IO_FAIL;
+end:
+	return ret_code;
+}
+
+struct lttng_event_rule *lttng_event_rule_kernel_tracepoint_create(void)
+{
+	struct lttng_event_rule *rule = NULL;
+	struct lttng_event_rule_kernel_tracepoint *tp_rule;
+	enum lttng_event_rule_status status;
+
+	tp_rule = (lttng_event_rule_kernel_tracepoint *) zmalloc(sizeof(struct lttng_event_rule_kernel_tracepoint));
+	if (!tp_rule) {
+		goto end;
+	}
+
+	rule = &tp_rule->parent;
+	lttng_event_rule_init(&tp_rule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_TRACEPOINT);
+	tp_rule->parent.validate = lttng_event_rule_kernel_tracepoint_validate;
+	tp_rule->parent.serialize = lttng_event_rule_kernel_tracepoint_serialize;
+	tp_rule->parent.equal = lttng_event_rule_kernel_tracepoint_is_equal;
+	tp_rule->parent.destroy = lttng_event_rule_kernel_tracepoint_destroy;
+	tp_rule->parent.generate_filter_bytecode =
+			lttng_event_rule_kernel_tracepoint_generate_filter_bytecode;
+	tp_rule->parent.get_filter =
+			lttng_event_rule_kernel_tracepoint_get_internal_filter;
+	tp_rule->parent.get_filter_bytecode =
+			lttng_event_rule_kernel_tracepoint_get_internal_filter_bytecode;
+	tp_rule->parent.generate_exclusions =
+			lttng_event_rule_kernel_tracepoint_generate_exclusions;
+	tp_rule->parent.hash = lttng_event_rule_kernel_tracepoint_hash;
+	tp_rule->parent.mi_serialize = lttng_event_rule_kernel_tracepoint_mi_serialize;
+
+	/* Not necessary for now. */
+	tp_rule->parent.generate_lttng_event = NULL;
+
+	/* Default pattern is '*'. */
+	status = lttng_event_rule_kernel_tracepoint_set_name_pattern(rule, "*");
+	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+		lttng_event_rule_destroy(rule);
+		rule = NULL;
+	}
+
+end:
+	return rule;
+}
+
+ssize_t lttng_event_rule_kernel_tracepoint_create_from_payload(
+		struct lttng_payload_view *view,
+		struct lttng_event_rule **_event_rule)
+{
+	ssize_t ret, offset = 0;
+	enum lttng_event_rule_status status;
+	const struct lttng_event_rule_kernel_tracepoint_comm *tracepoint_comm;
+	const char *pattern;
+	const char *filter_expression = NULL;
+	struct lttng_buffer_view current_buffer_view;
+	struct lttng_event_rule *rule = NULL;
+
+	if (!_event_rule) {
+		ret = -1;
+		goto end;
+	}
+
+	current_buffer_view = lttng_buffer_view_from_view(
+			&view->buffer, offset, sizeof(*tracepoint_comm));
+	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
+		ERR("Failed to initialize from malformed event rule kernel tracepoint: buffer too short to contain header.");
+		ret = -1;
+		goto end;
+	}
+
+	tracepoint_comm = (typeof(tracepoint_comm)) current_buffer_view.data;
+
+	/* Skip to payload. */
+	offset += current_buffer_view.size;
+
+	/* Map the pattern. */
+	current_buffer_view = lttng_buffer_view_from_view(
+			&view->buffer, offset, tracepoint_comm->pattern_len);
+
+	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
+		ret = -1;
+		goto end;
+	}
+
+	pattern = current_buffer_view.data;
+	if (!lttng_buffer_view_contains_string(&current_buffer_view, pattern,
+			tracepoint_comm->pattern_len)) {
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the pattern. */
+	offset += tracepoint_comm->pattern_len;
+
+	if (!tracepoint_comm->filter_expression_len) {
+		goto skip_filter_expression;
+	}
+
+	/* Map the filter_expression. */
+	current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset,
+			tracepoint_comm->filter_expression_len);
+	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
+		ret = -1;
+		goto end;
+	}
+
+	filter_expression = current_buffer_view.data;
+	if (!lttng_buffer_view_contains_string(&current_buffer_view,
+			filter_expression,
+			tracepoint_comm->filter_expression_len)) {
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the pattern. */
+	offset += tracepoint_comm->filter_expression_len;
+
+skip_filter_expression:
+
+	rule = lttng_event_rule_kernel_tracepoint_create();
+	if (!rule) {
+		ERR("Failed to create event rule kernel tracepoint.");
+		ret = -1;
+		goto end;
+	}
+
+	status = lttng_event_rule_kernel_tracepoint_set_name_pattern(rule, pattern);
+	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+		ERR("Failed to set event rule kernel tracepoint pattern.");
+		ret = -1;
+		goto end;
+	}
+
+	if (filter_expression) {
+		status = lttng_event_rule_kernel_tracepoint_set_filter(
+				rule, filter_expression);
+		if (status != LTTNG_EVENT_RULE_STATUS_OK) {
+			ERR("Failed to set event rule kernel tracepoint pattern.");
+			ret = -1;
+			goto end;
+		}
+	}
+
+	*_event_rule = rule;
+	rule = NULL;
+	ret = offset;
+end:
+	lttng_event_rule_destroy(rule);
+	return ret;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_tracepoint_set_name_pattern(
+		struct lttng_event_rule *rule, const char *pattern)
+{
+	char *pattern_copy = NULL;
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KERNEL_TRACEPOINT_EVENT_RULE(rule) || !pattern ||
+			strlen(pattern) == 0) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	pattern_copy = strdup(pattern);
+	if (!pattern_copy) {
+		status = LTTNG_EVENT_RULE_STATUS_ERROR;
+		goto end;
+	}
+
+	/* Normalize the pattern. */
+	strutils_normalize_star_glob_pattern(pattern_copy);
+
+	free(tracepoint->pattern);
+
+	tracepoint->pattern = pattern_copy;
+	pattern_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_tracepoint_get_name_pattern(
+		const struct lttng_event_rule *rule, const char **pattern)
+{
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KERNEL_TRACEPOINT_EVENT_RULE(rule) || !pattern) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	if (!tracepoint->pattern) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+	*pattern = tracepoint->pattern;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_tracepoint_set_filter(
+		struct lttng_event_rule *rule, const char *expression)
+{
+	char *expression_copy = NULL;
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KERNEL_TRACEPOINT_EVENT_RULE(rule) || !expression ||
+			strlen(expression) == 0) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	expression_copy = strdup(expression);
+	if (!expression_copy) {
+		PERROR("Failed to copy filter expression");
+		status = LTTNG_EVENT_RULE_STATUS_ERROR;
+		goto end;
+	}
+
+	if (tracepoint->filter_expression) {
+		free(tracepoint->filter_expression);
+	}
+
+	tracepoint->filter_expression = expression_copy;
+	expression_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_kernel_tracepoint_get_filter(
+		const struct lttng_event_rule *rule, const char **expression)
+{
+	struct lttng_event_rule_kernel_tracepoint *tracepoint;
+	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
+
+	if (!rule || !IS_KERNEL_TRACEPOINT_EVENT_RULE(rule) || !expression) {
+		status = LTTNG_EVENT_RULE_STATUS_INVALID;
+		goto end;
+	}
+
+	tracepoint = container_of(
+			rule, struct lttng_event_rule_kernel_tracepoint, parent);
+	if (!tracepoint->filter_expression) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+	*expression = tracepoint->filter_expression;
+end:
+	return status;
+}