*
*/
-#include <lttng/event-internal.h>
-#include <common/error.h>
+#include <common/align.hpp>
+#include <common/buffer-view.hpp>
+#include <common/compat/string.hpp>
+#include <common/dynamic-array.hpp>
+#include <common/dynamic-buffer.hpp>
+#include <common/error.hpp>
+#include <common/macros.hpp>
+#include <common/sessiond-comm/sessiond-comm.hpp>
+
+#include <lttng/constant.h>
+#include <lttng/event-internal.hpp>
+#include <lttng/event.h>
+#include <lttng/lttng-error.h>
+#include <lttng/userspace-probe-internal.hpp>
+
+namespace {
+struct event_list_element {
+ struct lttng_event *event;
+ struct lttng_event_exclusion *exclusions;
+ char *filter_expression;
+};
+} /* namespace */
+
+static void event_list_destructor(void *ptr)
+{
+ struct event_list_element *element = (struct event_list_element *) ptr;
+
+ free(element->filter_expression);
+ free(element->exclusions);
+ lttng_event_destroy(element->event);
+ free(element);
+}
struct lttng_event *lttng_event_copy(const struct lttng_event *event)
{
struct lttng_event *new_event;
struct lttng_event_extended *new_event_extended;
- new_event = (lttng_event *) zmalloc(sizeof(*event));
+ new_event = zmalloc<lttng_event>();
if (!new_event) {
PERROR("Error allocating event structure");
goto end;
* We need to create a new extended since the previous pointer is now
* invalid.
*/
- new_event_extended = (lttng_event_extended *) zmalloc(sizeof(*new_event_extended));
+ new_event_extended = zmalloc<lttng_event_extended>();
if (!new_event_extended) {
PERROR("Error allocating event extended structure");
goto error;
return new_event;
error:
free(new_event);
- new_event = NULL;
+ new_event = nullptr;
goto end;
}
+
+static int lttng_event_probe_attr_serialize(const struct lttng_event_probe_attr *probe,
+ struct lttng_payload *payload)
+{
+ int ret;
+ size_t symbol_name_len;
+ struct lttng_event_probe_attr_comm comm = {};
+
+ symbol_name_len = lttng_strnlen(probe->symbol_name, sizeof(probe->symbol_name));
+ if (symbol_name_len == sizeof(probe->symbol_name)) {
+ /* Not null-termintated. */
+ ret = -1;
+ goto end;
+ }
+
+ /* Include the null terminator. */
+ symbol_name_len += 1;
+
+ comm.symbol_name_len = (uint32_t) symbol_name_len;
+ comm.addr = probe->addr;
+ comm.offset = probe->addr;
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &comm, sizeof(comm));
+ if (ret < 0) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, probe->symbol_name, symbol_name_len);
+end:
+ return ret;
+}
+
+static int lttng_event_function_attr_serialize(const struct lttng_event_function_attr *function,
+ struct lttng_payload *payload)
+{
+ int ret;
+ size_t symbol_name_len;
+ struct lttng_event_function_attr_comm comm;
+
+ comm.symbol_name_len = 0;
+
+ symbol_name_len = lttng_strnlen(function->symbol_name, sizeof(function->symbol_name));
+ if (symbol_name_len == sizeof(function->symbol_name)) {
+ /* Not null-termintated. */
+ ret = -1;
+ goto end;
+ }
+
+ /* Include the null terminator. */
+ symbol_name_len += 1;
+
+ comm.symbol_name_len = (uint32_t) symbol_name_len;
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &comm, sizeof(comm));
+ if (ret < 0) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, function->symbol_name, symbol_name_len);
+end:
+ return ret;
+}
+
+static ssize_t
+lttng_event_probe_attr_create_from_payload(struct lttng_payload_view *view,
+ struct lttng_event_probe_attr **probe_attr)
+{
+ ssize_t ret, offset = 0;
+ const struct lttng_event_probe_attr_comm *comm;
+ struct lttng_event_probe_attr *local_attr = nullptr;
+ struct lttng_payload_view comm_view =
+ lttng_payload_view_from_view(view, offset, sizeof(*comm));
+
+ if (!lttng_payload_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) comm_view.buffer.data;
+ offset += sizeof(*comm);
+
+ local_attr = zmalloc<lttng_event_probe_attr>();
+ if (local_attr == nullptr) {
+ ret = -1;
+ goto end;
+ }
+
+ local_attr->addr = comm->addr;
+ local_attr->offset = comm->offset;
+
+ {
+ const char *name;
+ struct lttng_payload_view name_view =
+ lttng_payload_view_from_view(view, offset, comm->symbol_name_len);
+
+ if (!lttng_payload_view_is_valid(&name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = name_view.buffer.data;
+
+ if (!lttng_buffer_view_contains_string(
+ &name_view.buffer, name, comm->symbol_name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_strncpy(local_attr->symbol_name, name, sizeof(local_attr->symbol_name));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += comm->symbol_name_len;
+ }
+
+ *probe_attr = local_attr;
+ local_attr = nullptr;
+ ret = offset;
+end:
+ free(local_attr);
+ return ret;
+}
+
+static ssize_t
+lttng_event_function_attr_create_from_payload(struct lttng_payload_view *view,
+ struct lttng_event_function_attr **function_attr)
+{
+ ssize_t ret, offset = 0;
+ const struct lttng_event_function_attr_comm *comm;
+ struct lttng_event_function_attr *local_attr = nullptr;
+ struct lttng_payload_view comm_view =
+ lttng_payload_view_from_view(view, offset, sizeof(*comm));
+
+ if (!lttng_payload_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) view->buffer.data;
+ offset += sizeof(*comm);
+
+ local_attr = zmalloc<lttng_event_function_attr>();
+ if (local_attr == nullptr) {
+ ret = -1;
+ goto end;
+ }
+
+ {
+ const char *name;
+ struct lttng_payload_view name_view =
+ lttng_payload_view_from_view(view, offset, comm->symbol_name_len);
+
+ if (!lttng_payload_view_is_valid(&name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = name_view.buffer.data;
+
+ if (!lttng_buffer_view_contains_string(
+ &name_view.buffer, name, comm->symbol_name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_strncpy(local_attr->symbol_name, name, sizeof(local_attr->symbol_name));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += comm->symbol_name_len;
+ }
+
+ *function_attr = local_attr;
+ local_attr = nullptr;
+ ret = offset;
+end:
+ free(local_attr);
+ return ret;
+}
+
+static ssize_t lttng_event_exclusions_create_from_payload(struct lttng_payload_view *view,
+ uint32_t count,
+ struct lttng_event_exclusion **exclusions)
+{
+ ssize_t ret, offset = 0;
+ const size_t size = (count * LTTNG_SYMBOL_NAME_LEN);
+ uint32_t i;
+ const struct lttng_event_exclusion_comm *comm;
+ struct lttng_event_exclusion *local_exclusions;
+
+ local_exclusions =
+ zmalloc<lttng_event_exclusion>(sizeof(struct lttng_event_exclusion) + size);
+ if (!local_exclusions) {
+ ret = -1;
+ goto end;
+ }
+
+ local_exclusions->count = count;
+
+ for (i = 0; i < count; i++) {
+ const char *string;
+ struct lttng_buffer_view string_view;
+ const struct lttng_buffer_view comm_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, sizeof(*comm));
+
+ if (!lttng_buffer_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) comm_view.data;
+ offset += sizeof(*comm);
+
+ string_view = lttng_buffer_view_from_view(&view->buffer, offset, comm->len);
+
+ if (!lttng_buffer_view_is_valid(&string_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ string = string_view.data;
+
+ if (!lttng_buffer_view_contains_string(&string_view, string, comm->len)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_strncpy(LTTNG_EVENT_EXCLUSION_NAME_AT(local_exclusions, i),
+ string,
+ sizeof(LTTNG_EVENT_EXCLUSION_NAME_AT(local_exclusions, i)));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += comm->len;
+ }
+
+ *exclusions = local_exclusions;
+ local_exclusions = nullptr;
+ ret = offset;
+end:
+ free(local_exclusions);
+ return ret;
+}
+
+ssize_t lttng_event_create_from_payload(struct lttng_payload_view *view,
+ struct lttng_event **out_event,
+ struct lttng_event_exclusion **out_exclusion,
+ char **out_filter_expression,
+ struct lttng_bytecode **out_bytecode)
+{
+ ssize_t ret, offset = 0;
+ struct lttng_event *local_event = nullptr;
+ struct lttng_event_exclusion *local_exclusions = nullptr;
+ struct lttng_bytecode *local_bytecode = nullptr;
+ char *local_filter_expression = nullptr;
+ const struct lttng_event_comm *event_comm;
+ struct lttng_event_function_attr *local_function_attr = nullptr;
+ struct lttng_event_probe_attr *local_probe_attr = nullptr;
+ struct lttng_userspace_probe_location *local_userspace_probe_location = nullptr;
+
+ /*
+ * Only event is obligatory, the other output argument are optional and
+ * depends on what the caller is interested in.
+ */
+ assert(out_event);
+ assert(view);
+
+ {
+ struct lttng_payload_view comm_view =
+ lttng_payload_view_from_view(view, offset, sizeof(*event_comm));
+
+ if (!lttng_payload_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ /* lttng_event_comm header */
+ event_comm = (typeof(event_comm)) comm_view.buffer.data;
+ offset += sizeof(*event_comm);
+ }
+
+ local_event = lttng_event_create();
+ if (local_event == nullptr) {
+ ret = -1;
+ goto end;
+ }
+
+ local_event->type = (enum lttng_event_type) event_comm->event_type;
+ local_event->loglevel_type = (enum lttng_loglevel_type) event_comm->loglevel_type;
+ local_event->loglevel = event_comm->loglevel;
+ local_event->enabled = !!event_comm->enabled;
+ local_event->pid = event_comm->pid;
+ local_event->flags = (enum lttng_event_flag) event_comm->flags;
+
+ {
+ const char *name;
+ const struct lttng_buffer_view name_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, event_comm->name_len);
+
+ if (!lttng_buffer_view_is_valid(&name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = (const char *) name_view.data;
+
+ if (!lttng_buffer_view_contains_string(&name_view, name, event_comm->name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_strncpy(local_event->name, name, sizeof(local_event->name));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += event_comm->name_len;
+ }
+
+ /* Exclusions */
+ if (event_comm->exclusion_count == 0) {
+ goto deserialize_filter_expression;
+ }
+
+ {
+ struct lttng_payload_view exclusions_view =
+ lttng_payload_view_from_view(view, offset, -1);
+
+ if (!lttng_payload_view_is_valid(&exclusions_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_event_exclusions_create_from_payload(
+ &exclusions_view, event_comm->exclusion_count, &local_exclusions);
+ if (ret < 0) {
+ ret = -1;
+ goto end;
+ }
+ offset += ret;
+
+ local_event->exclusion = 1;
+ }
+
+deserialize_filter_expression:
+
+ if (event_comm->filter_expression_len == 0) {
+ if (event_comm->bytecode_len != 0) {
+ /*
+ * This is an invalid event payload.
+ *
+ * Filter expression without bytecode is possible but
+ * not the other way around.
+ * */
+ ret = -1;
+ goto end;
+ }
+ goto deserialize_event_type_payload;
+ }
+
+ {
+ const char *filter_expression_buffer;
+ struct lttng_buffer_view filter_expression_view = lttng_buffer_view_from_view(
+ &view->buffer, offset, event_comm->filter_expression_len);
+
+ if (!lttng_buffer_view_is_valid(&filter_expression_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ filter_expression_buffer = filter_expression_view.data;
+
+ if (!lttng_buffer_view_contains_string(&filter_expression_view,
+ filter_expression_buffer,
+ event_comm->filter_expression_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ local_filter_expression =
+ lttng_strndup(filter_expression_buffer, event_comm->filter_expression_len);
+ if (!local_filter_expression) {
+ ret = -1;
+ goto end;
+ }
+
+ local_event->filter = 1;
+
+ offset += event_comm->filter_expression_len;
+ }
+
+ if (event_comm->bytecode_len == 0) {
+ /*
+ * Filter expression can be present but without bytecode
+ * when dealing with event listing.
+ */
+ goto deserialize_event_type_payload;
+ }
+
+ /* Bytecode */
+ {
+ struct lttng_payload_view bytecode_view =
+ lttng_payload_view_from_view(view, offset, event_comm->bytecode_len);
+
+ if (!lttng_payload_view_is_valid(&bytecode_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ local_bytecode = zmalloc<lttng_bytecode>(event_comm->bytecode_len);
+ if (!local_bytecode) {
+ ret = -1;
+ goto end;
+ }
+
+ memcpy(local_bytecode, bytecode_view.buffer.data, event_comm->bytecode_len);
+ if ((local_bytecode->len + sizeof(*local_bytecode)) != event_comm->bytecode_len) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += event_comm->bytecode_len;
+ }
+
+deserialize_event_type_payload:
+ /* Event type specific payload */
+ switch (local_event->type) {
+ case LTTNG_EVENT_FUNCTION:
+ /* Fallthrough */
+ case LTTNG_EVENT_PROBE:
+ {
+ struct lttng_payload_view probe_attr_view = lttng_payload_view_from_view(
+ view, offset, event_comm->lttng_event_probe_attr_len);
+
+ if (event_comm->lttng_event_probe_attr_len == 0) {
+ ret = -1;
+ goto end;
+ }
+
+ if (!lttng_payload_view_is_valid(&probe_attr_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_event_probe_attr_create_from_payload(&probe_attr_view,
+ &local_probe_attr);
+ if (ret < 0 || ret != event_comm->lttng_event_probe_attr_len) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Copy to the local event. */
+ memcpy(&local_event->attr.probe, local_probe_attr, sizeof(local_event->attr.probe));
+
+ offset += ret;
+ break;
+ }
+ case LTTNG_EVENT_FUNCTION_ENTRY:
+ {
+ struct lttng_payload_view function_attr_view = lttng_payload_view_from_view(
+ view, offset, event_comm->lttng_event_function_attr_len);
+
+ if (event_comm->lttng_event_function_attr_len == 0) {
+ ret = -1;
+ goto end;
+ }
+
+ if (!lttng_payload_view_is_valid(&function_attr_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_event_function_attr_create_from_payload(&function_attr_view,
+ &local_function_attr);
+ if (ret < 0 || ret != event_comm->lttng_event_function_attr_len) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Copy to the local event. */
+ memcpy(&local_event->attr.ftrace,
+ local_function_attr,
+ sizeof(local_event->attr.ftrace));
+
+ offset += ret;
+
+ break;
+ }
+ case LTTNG_EVENT_USERSPACE_PROBE:
+ {
+ struct lttng_payload_view userspace_probe_location_view =
+ lttng_payload_view_from_view(
+ view, offset, event_comm->userspace_probe_location_len);
+
+ if (event_comm->userspace_probe_location_len == 0) {
+ ret = -1;
+ goto end;
+ }
+
+ if (!lttng_payload_view_is_valid(&userspace_probe_location_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_userspace_probe_location_create_from_payload(
+ &userspace_probe_location_view, &local_userspace_probe_location);
+ if (ret < 0) {
+ WARN("Failed to create a userspace probe location from the received buffer");
+ ret = -1;
+ goto end;
+ }
+
+ if (ret != event_comm->userspace_probe_location_len) {
+ WARN("Userspace probe location from the received buffer is not the advertised length: header length = %" PRIu32
+ ", payload length = %zd",
+ event_comm->userspace_probe_location_len,
+ ret);
+ ret = -1;
+ goto end;
+ }
+
+ /* Attach the probe location to the event. */
+ ret = lttng_event_set_userspace_probe_location(local_event,
+ local_userspace_probe_location);
+ if (ret) {
+ ret = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto end;
+ }
+
+ /*
+ * Userspace probe location object ownership transfered to the
+ * event object.
+ */
+ local_userspace_probe_location = nullptr;
+ offset += event_comm->userspace_probe_location_len;
+ break;
+ }
+ case LTTNG_EVENT_TRACEPOINT:
+ /* Fallthrough */
+ case LTTNG_EVENT_ALL:
+ /* Fallthrough */
+ case LTTNG_EVENT_SYSCALL:
+ /* Fallthrough */
+ case LTTNG_EVENT_NOOP:
+ /* Nothing to do here */
+ break;
+ default:
+ ret = LTTNG_ERR_UND;
+ goto end;
+ break;
+ }
+
+ /* Transfer ownership to the caller. */
+ *out_event = local_event;
+ local_event = nullptr;
+
+ if (out_bytecode) {
+ *out_bytecode = local_bytecode;
+ local_bytecode = nullptr;
+ }
+
+ if (out_exclusion) {
+ *out_exclusion = local_exclusions;
+ local_exclusions = nullptr;
+ }
+
+ if (out_filter_expression) {
+ *out_filter_expression = local_filter_expression;
+ local_filter_expression = nullptr;
+ }
+
+ ret = offset;
+end:
+ lttng_event_destroy(local_event);
+ lttng_userspace_probe_location_destroy(local_userspace_probe_location);
+ free(local_filter_expression);
+ free(local_exclusions);
+ free(local_bytecode);
+ free(local_function_attr);
+ free(local_probe_attr);
+ return ret;
+}
+
+int lttng_event_serialize(const struct lttng_event *event,
+ unsigned int exclusion_count,
+ const char *const *exclusion_list,
+ const char *filter_expression,
+ size_t bytecode_len,
+ struct lttng_bytecode *bytecode,
+ struct lttng_payload *payload)
+{
+ int ret;
+ unsigned int i;
+ size_t header_offset, size_before_payload;
+ size_t name_len;
+ struct lttng_event_comm event_comm = {};
+ struct lttng_event_comm *header;
+
+ assert(event);
+ assert(payload);
+ assert(exclusion_count == 0 || exclusion_list);
+
+ /* Save the header location for later in-place header update. */
+ header_offset = payload->buffer.size;
+
+ name_len = lttng_strnlen(event->name, sizeof(event->name));
+ if (name_len == sizeof(event->name)) {
+ /* Event name is not NULL-terminated. */
+ ret = -1;
+ goto end;
+ }
+
+ /* Add null termination. */
+ name_len += 1;
+
+ if (exclusion_count > UINT32_MAX) {
+ /* Possible overflow. */
+ ret = -1;
+ goto end;
+ }
+
+ if (bytecode_len > UINT32_MAX) {
+ /* Possible overflow. */
+ ret = -1;
+ goto end;
+ }
+
+ event_comm.name_len = (uint32_t) name_len;
+ event_comm.event_type = (int8_t) event->type;
+ event_comm.loglevel_type = (int8_t) event->loglevel_type;
+ event_comm.loglevel = (int32_t) event->loglevel;
+ event_comm.enabled = (int8_t) event->enabled;
+ event_comm.pid = (int32_t) event->pid;
+ event_comm.exclusion_count = (uint32_t) exclusion_count;
+ event_comm.bytecode_len = (uint32_t) bytecode_len;
+ event_comm.flags = (int32_t) event->flags;
+
+ if (filter_expression) {
+ event_comm.filter_expression_len = strlen(filter_expression) + 1;
+ }
+
+ /* Header */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &event_comm, sizeof(event_comm));
+ if (ret) {
+ goto end;
+ }
+
+ /* Event name */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, event->name, name_len);
+ if (ret) {
+ goto end;
+ }
+
+ /* Exclusions */
+ for (i = 0; i < exclusion_count; i++) {
+ const size_t exclusion_len =
+ lttng_strnlen(*(exclusion_list + i), LTTNG_SYMBOL_NAME_LEN);
+ struct lttng_event_exclusion_comm exclusion_header = {};
+
+ exclusion_header.len = (uint32_t) exclusion_len + 1;
+
+ if (exclusion_len == LTTNG_SYMBOL_NAME_LEN) {
+ /* Exclusion is not NULL-terminated. */
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(
+ &payload->buffer, &exclusion_header, sizeof(exclusion_header));
+ if (ret) {
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(
+ &payload->buffer, *(exclusion_list + i), exclusion_len + 1);
+ if (ret) {
+ goto end;
+ }
+ }
+
+ /* Filter expression and its bytecode */
+ if (filter_expression) {
+ ret = lttng_dynamic_buffer_append(
+ &payload->buffer, filter_expression, event_comm.filter_expression_len);
+ if (ret) {
+ goto end;
+ }
+
+ /*
+ * Bytecode can be absent when we serialize to the client
+ * for listing.
+ */
+ if (bytecode) {
+ ret = lttng_dynamic_buffer_append(&payload->buffer, bytecode, bytecode_len);
+ if (ret) {
+ goto end;
+ }
+ }
+ }
+
+ size_before_payload = payload->buffer.size;
+
+ /* Event type specific payload */
+ switch (event->type) {
+ case LTTNG_EVENT_FUNCTION:
+ /* Fallthrough */
+ case LTTNG_EVENT_PROBE:
+ ret = lttng_event_probe_attr_serialize(&event->attr.probe, payload);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ header =
+ (struct lttng_event_comm *) ((char *) payload->buffer.data + header_offset);
+ header->lttng_event_probe_attr_len = payload->buffer.size - size_before_payload;
+
+ break;
+ case LTTNG_EVENT_FUNCTION_ENTRY:
+ ret = lttng_event_function_attr_serialize(&event->attr.ftrace, payload);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Update the lttng_event_function_attr len. */
+ header =
+ (struct lttng_event_comm *) ((char *) payload->buffer.data + header_offset);
+ header->lttng_event_function_attr_len = payload->buffer.size - size_before_payload;
+
+ break;
+ case LTTNG_EVENT_USERSPACE_PROBE:
+ {
+ const struct lttng_event_extended *ev_ext =
+ (const struct lttng_event_extended *) event->extended.ptr;
+
+ assert(event->extended.ptr);
+ assert(ev_ext->probe_location);
+
+ size_before_payload = payload->buffer.size;
+ if (ev_ext->probe_location) {
+ /*
+ * lttng_userspace_probe_location_serialize returns the
+ * number of bytes that were appended to the buffer.
+ */
+ ret = lttng_userspace_probe_location_serialize(ev_ext->probe_location,
+ payload);
+ if (ret < 0) {
+ goto end;
+ }
+
+ ret = 0;
+
+ /* Update the userspace probe location len. */
+ header = (struct lttng_event_comm *) ((char *) payload->buffer.data +
+ header_offset);
+ header->userspace_probe_location_len =
+ payload->buffer.size - size_before_payload;
+ }
+ break;
+ }
+ case LTTNG_EVENT_TRACEPOINT:
+ /* Fallthrough */
+ case LTTNG_EVENT_ALL:
+ /* Fallthrough */
+ default:
+ /* Nothing to do here. */
+ break;
+ }
+
+end:
+ return ret;
+}
+
+static ssize_t lttng_event_context_app_populate_from_payload(const struct lttng_payload_view *view,
+ struct lttng_event_context *event_ctx)
+{
+ ssize_t ret, offset = 0;
+ const struct lttng_event_context_app_comm *comm;
+ char *provider_name = nullptr, *context_name = nullptr;
+ size_t provider_name_len, context_name_len;
+ const struct lttng_buffer_view comm_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, sizeof(*comm));
+
+ assert(event_ctx->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
+
+ if (!lttng_buffer_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) comm_view.data;
+ offset += sizeof(*comm);
+
+ provider_name_len = comm->provider_name_len;
+ context_name_len = comm->ctx_name_len;
+
+ if (provider_name_len == 0 || context_name_len == 0) {
+ /*
+ * Application provider and context names MUST
+ * be provided.
+ */
+ ret = -1;
+ goto end;
+ }
+
+ {
+ const char *name;
+ const struct lttng_buffer_view provider_name_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, provider_name_len);
+
+ if (!lttng_buffer_view_is_valid(&provider_name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = provider_name_view.data;
+
+ if (!lttng_buffer_view_contains_string(
+ &provider_name_view, name, provider_name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ provider_name = lttng_strndup(name, provider_name_len);
+ if (!provider_name) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += provider_name_len;
+ }
+
+ {
+ const char *name;
+ const struct lttng_buffer_view context_name_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, context_name_len);
+
+ if (!lttng_buffer_view_is_valid(&context_name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = context_name_view.data;
+
+ if (!lttng_buffer_view_contains_string(&context_name_view, name, context_name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ context_name = lttng_strndup(name, context_name_len);
+ if (!context_name) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += context_name_len;
+ }
+
+ /* Transfer ownership of the strings */
+ event_ctx->u.app_ctx.provider_name = provider_name;
+ event_ctx->u.app_ctx.ctx_name = context_name;
+ provider_name = nullptr;
+ context_name = nullptr;
+
+ ret = offset;
+end:
+ free(provider_name);
+ free(context_name);
+
+ return ret;
+}
+
+static ssize_t
+lttng_event_context_perf_counter_populate_from_payload(const struct lttng_payload_view *view,
+ struct lttng_event_context *event_ctx)
+{
+ int ret;
+ ssize_t consumed, offset = 0;
+ const struct lttng_event_context_perf_counter_comm *comm;
+ size_t name_len;
+ const struct lttng_buffer_view comm_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, sizeof(*comm));
+
+ assert(event_ctx->ctx == LTTNG_EVENT_CONTEXT_PERF_COUNTER ||
+ event_ctx->ctx == LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER ||
+ event_ctx->ctx == LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER);
+
+ if (!lttng_buffer_view_is_valid(&comm_view)) {
+ consumed = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) comm_view.data;
+ offset += sizeof(*comm);
+
+ name_len = comm->name_len;
+
+ {
+ const char *name;
+ const struct lttng_buffer_view provider_name_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, name_len);
+
+ if (!lttng_buffer_view_is_valid(&provider_name_view)) {
+ consumed = -1;
+ goto end;
+ }
+
+ name = provider_name_view.data;
+
+ if (!lttng_buffer_view_contains_string(&provider_name_view, name, name_len)) {
+ consumed = -1;
+ goto end;
+ }
+
+ ret = lttng_strncpy(event_ctx->u.perf_counter.name,
+ name,
+ sizeof(event_ctx->u.perf_counter.name));
+ if (ret) {
+ consumed = -1;
+ goto end;
+ }
+ offset += name_len;
+ }
+
+ event_ctx->u.perf_counter.config = comm->config;
+ event_ctx->u.perf_counter.type = comm->type;
+
+ consumed = offset;
+
+end:
+ return consumed;
+}
+
+ssize_t lttng_event_context_create_from_payload(struct lttng_payload_view *view,
+ struct lttng_event_context **event_ctx)
+{
+ ssize_t ret, offset = 0;
+ const struct lttng_event_context_comm *comm;
+ struct lttng_event_context *local_context = nullptr;
+ struct lttng_buffer_view comm_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, sizeof(*comm));
+
+ assert(event_ctx);
+ assert(view);
+
+ if (!lttng_buffer_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ comm = (typeof(comm)) comm_view.data;
+ offset += sizeof(*comm);
+
+ local_context = zmalloc<lttng_event_context>();
+ if (!local_context) {
+ ret = -1;
+ goto end;
+ }
+
+ local_context->ctx = (lttng_event_context_type) comm->type;
+
+ {
+ struct lttng_payload_view subtype_view =
+ lttng_payload_view_from_view(view, offset, -1);
+
+ switch (local_context->ctx) {
+ case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
+ ret = lttng_event_context_app_populate_from_payload(&subtype_view,
+ local_context);
+ break;
+ case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
+ case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
+ case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
+ ret = lttng_event_context_perf_counter_populate_from_payload(&subtype_view,
+ local_context);
+ break;
+ default:
+ /* Nothing else to deserialize. */
+ ret = 0;
+ break;
+ }
+ }
+
+ if (ret < 0) {
+ goto end;
+ }
+
+ offset += ret;
+
+ *event_ctx = local_context;
+ local_context = nullptr;
+ ret = offset;
+
+end:
+ free(local_context);
+ return ret;
+}
+
+static int lttng_event_context_app_serialize(struct lttng_event_context *context,
+ struct lttng_payload *payload)
+{
+ int ret;
+ struct lttng_event_context_app_comm comm = {};
+ size_t provider_len, ctx_len;
+ const char *provider_name;
+ const char *ctx_name;
+
+ assert(payload);
+ assert(context);
+ assert(context->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT);
+
+ provider_name = context->u.app_ctx.provider_name;
+ ctx_name = context->u.app_ctx.ctx_name;
+
+ if (!provider_name || !ctx_name) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ provider_len = strlen(provider_name);
+ if (provider_len == 0) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /* Include the null terminator. */
+ provider_len += 1;
+ comm.provider_name_len = provider_len;
+
+ ctx_len = strlen(ctx_name);
+ if (ctx_len == 0) {
+ ret = -LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /* Include the null terminator. */
+ ctx_len += 1;
+ comm.ctx_name_len = ctx_len;
+
+ /* Header */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &comm, sizeof(comm));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, provider_name, provider_len);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, ctx_name, ctx_len);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static int lttng_event_context_perf_counter_serialize(struct lttng_event_perf_counter_ctx *context,
+ struct lttng_payload *payload)
+{
+ int ret;
+ struct lttng_event_context_perf_counter_comm comm = {};
+
+ assert(payload);
+ assert(context);
+
+ comm.config = context->config;
+ comm.type = context->type;
+ comm.name_len = lttng_strnlen(context->name, sizeof(context->name));
+
+ if (comm.name_len == sizeof(context->name)) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Include the null terminator. */
+ comm.name_len += 1;
+
+ /* Header */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &comm, sizeof(comm));
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(&payload->buffer, context->name, comm.name_len);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+int lttng_event_context_serialize(struct lttng_event_context *context,
+ struct lttng_payload *payload)
+{
+ int ret;
+ struct lttng_event_context_comm context_comm;
+
+ context_comm.type = 0;
+
+ assert(context);
+ assert(payload);
+
+ context_comm.type = (uint32_t) context->ctx;
+
+ /* Header */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, &context_comm, sizeof(context_comm));
+ if (ret) {
+ goto end;
+ }
+
+ switch (context->ctx) {
+ case LTTNG_EVENT_CONTEXT_APP_CONTEXT:
+ ret = lttng_event_context_app_serialize(context, payload);
+ break;
+ case LTTNG_EVENT_CONTEXT_PERF_COUNTER:
+ case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
+ case LTTNG_EVENT_CONTEXT_PERF_CPU_COUNTER:
+ ret = lttng_event_context_perf_counter_serialize(&context->u.perf_counter, payload);
+ break;
+ default:
+ /* Nothing else to serialize. */
+ break;
+ }
+
+ if (ret) {
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+void lttng_event_context_destroy(struct lttng_event_context *context)
+{
+ if (!context) {
+ return;
+ }
+
+ if (context->ctx == LTTNG_EVENT_CONTEXT_APP_CONTEXT) {
+ free(context->u.app_ctx.provider_name);
+ free(context->u.app_ctx.ctx_name);
+ }
+
+ free(context);
+}
+
+/*
+ * This is a specialized populate for lttng_event_field since it ignores
+ * the extension field of the lttng_event struct and simply copies what it can
+ * to the internal struct lttng_event of a lttng_event_field.
+ */
+static void lttng_event_field_populate_lttng_event_from_event(const struct lttng_event *src,
+ struct lttng_event *destination)
+{
+ memcpy(destination, src, sizeof(*destination));
+
+ /* Remove all possible dynamic data from the destination event rule. */
+ destination->extended.ptr = nullptr;
+}
+
+ssize_t lttng_event_field_create_from_payload(struct lttng_payload_view *view,
+ struct lttng_event_field **field)
+{
+ ssize_t ret, offset = 0;
+ struct lttng_event_field *local_event_field = nullptr;
+ struct lttng_event *event = nullptr;
+ const struct lttng_event_field_comm *comm;
+ const char *name = nullptr;
+
+ assert(field);
+ assert(view);
+
+ {
+ const struct lttng_buffer_view comm_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, sizeof(*comm));
+
+ if (!lttng_buffer_view_is_valid(&comm_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ /* lttng_event_field_comm header */
+ comm = (const lttng_event_field_comm *) comm_view.data;
+ offset += sizeof(*comm);
+ }
+
+ local_event_field = zmalloc<lttng_event_field>();
+ if (!local_event_field) {
+ ret = -1;
+ goto end;
+ }
+
+ local_event_field->type = (lttng_event_field_type) comm->type;
+ local_event_field->nowrite = comm->nowrite;
+
+ /* Field name */
+ {
+ const struct lttng_buffer_view name_view =
+ lttng_buffer_view_from_view(&view->buffer, offset, comm->name_len);
+
+ if (!lttng_buffer_view_is_valid(&name_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ name = name_view.data;
+
+ if (!lttng_buffer_view_contains_string(&name_view, name_view.data, comm->name_len)) {
+ ret = -1;
+ goto end;
+ }
+
+ if (comm->name_len > LTTNG_SYMBOL_NAME_LEN - 1) {
+ /* Name is too long.*/
+ ret = -1;
+ goto end;
+ }
+
+ offset += comm->name_len;
+ }
+
+ /* Event */
+ {
+ struct lttng_payload_view event_view =
+ lttng_payload_view_from_view(view, offset, comm->event_len);
+
+ if (!lttng_payload_view_is_valid(&event_view)) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = lttng_event_create_from_payload(
+ &event_view, &event, nullptr, nullptr, nullptr);
+ if (ret != comm->event_len) {
+ ret = -1;
+ goto end;
+ }
+
+ offset += ret;
+ }
+
+ assert(name);
+ assert(event);
+
+ if (lttng_strncpy(
+ local_event_field->field_name, name, sizeof(local_event_field->field_name))) {
+ ret = -1;
+ goto end;
+ }
+
+ lttng_event_field_populate_lttng_event_from_event(event, &local_event_field->event);
+
+ *field = local_event_field;
+ local_event_field = nullptr;
+ ret = offset;
+end:
+ lttng_event_destroy(event);
+ free(local_event_field);
+ return ret;
+}
+
+int lttng_event_field_serialize(const struct lttng_event_field *field,
+ struct lttng_payload *payload)
+{
+ int ret;
+ size_t header_offset, size_before_event;
+ size_t name_len;
+ struct lttng_event_field_comm event_field_comm = {};
+ struct lttng_event_field_comm *header;
+
+ assert(field);
+ assert(payload);
+
+ /* Save the header location for later in-place header update. */
+ header_offset = payload->buffer.size;
+
+ name_len = strnlen(field->field_name, sizeof(field->field_name));
+ if (name_len == sizeof(field->field_name)) {
+ /* Event name is not NULL-terminated. */
+ ret = -1;
+ goto end;
+ }
+
+ /* Add null termination. */
+ name_len += 1;
+
+ event_field_comm.type = field->type;
+ event_field_comm.nowrite = (uint8_t) field->nowrite;
+ event_field_comm.name_len = name_len;
+
+ /* Header */
+ ret = lttng_dynamic_buffer_append(
+ &payload->buffer, &event_field_comm, sizeof(event_field_comm));
+ if (ret) {
+ goto end;
+ }
+
+ /* Field name */
+ ret = lttng_dynamic_buffer_append(&payload->buffer, field->field_name, name_len);
+ if (ret) {
+ goto end;
+ }
+
+ size_before_event = payload->buffer.size;
+ ret = lttng_event_serialize(&field->event, 0, nullptr, nullptr, 0, nullptr, payload);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ /* Update the event len. */
+ header = (struct lttng_event_field_comm *) ((char *) payload->buffer.data + header_offset);
+ header->event_len = payload->buffer.size - size_before_event;
+
+end:
+ return ret;
+}
+
+static enum lttng_error_code compute_flattened_size(struct lttng_dynamic_pointer_array *events,
+ size_t *size)
+{
+ enum lttng_error_code ret_code;
+ int ret = 0;
+ size_t storage_req, event_count, i;
+
+ assert(size);
+ assert(events);
+
+ event_count = lttng_dynamic_pointer_array_get_count(events);
+
+ /* The basic struct lttng_event */
+ storage_req = event_count * sizeof(struct lttng_event);
+
+ /* The struct·lttng_event_extended */
+ storage_req += event_count * sizeof(struct lttng_event_extended);
+
+ for (i = 0; i < event_count; i++) {
+ int probe_storage_req = 0;
+ const struct event_list_element *element =
+ (const struct event_list_element *) lttng_dynamic_pointer_array_get_pointer(
+ events, i);
+ const struct lttng_userspace_probe_location *location = nullptr;
+
+ location = lttng_event_get_userspace_probe_location(element->event);
+ if (location) {
+ ret = lttng_userspace_probe_location_flatten(location, nullptr);
+ if (ret < 0) {
+ ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto end;
+ }
+
+ probe_storage_req = ret;
+ }
+
+ if (element->filter_expression) {
+ storage_req += strlen(element->filter_expression) + 1;
+ }
+
+ if (element->exclusions) {
+ storage_req += element->exclusions->count * LTTNG_SYMBOL_NAME_LEN;
+ }
+
+ /* Padding to ensure the flat probe is aligned. */
+ storage_req = lttng_align_ceil(storage_req, sizeof(uint64_t));
+ storage_req += probe_storage_req;
+ }
+
+ *size = storage_req;
+ ret_code = LTTNG_OK;
+
+end:
+ return ret_code;
+}
+
+/*
+ * Flatten a list of struct lttng_event.
+ *
+ * The buffer that is returned to the API client must contain a "flat" version
+ * of the events that are returned. In other words, all pointers within an
+ * lttng_event must point to a location within the returned buffer so that the
+ * user may free everything by simply calling free() on the returned buffer.
+ * This is needed in order to maintain API compatibility.
+ *
+ * A first pass is performed to compute the size of the buffer that must be
+ * allocated. A second pass is then performed to setup the returned events so
+ * that their members always point within the buffer.
+ *
+ * The layout of the returned buffer is as follows:
+ * - struct lttng_event[nb_events],
+ * - nb_events times the following:
+ * - struct lttng_event_extended,
+ * - filter_expression
+ * - exclusions
+ * - padding to align to 64-bits
+ * - flattened version of userspace_probe_location
+ */
+static enum lttng_error_code flatten_lttng_events(struct lttng_dynamic_pointer_array *events,
+ struct lttng_event **flattened_events)
+{
+ enum lttng_error_code ret_code;
+ int ret, i;
+ size_t storage_req;
+ struct lttng_dynamic_buffer local_flattened_events;
+ int nb_events;
+
+ assert(events);
+ assert(flattened_events);
+
+ lttng_dynamic_buffer_init(&local_flattened_events);
+ nb_events = lttng_dynamic_pointer_array_get_count(events);
+
+ ret_code = compute_flattened_size(events, &storage_req);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+
+ /*
+ * We must ensure that "local_flattened_events" is never resized so as
+ * to preserve the validity of the flattened objects.
+ */
+ ret = lttng_dynamic_buffer_set_capacity(&local_flattened_events, storage_req);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /* Start by laying the struct lttng_event */
+ for (i = 0; i < nb_events; i++) {
+ const struct event_list_element *element =
+ (const struct event_list_element *) lttng_dynamic_pointer_array_get_pointer(
+ events, i);
+
+ if (!element) {
+ ret_code = LTTNG_ERR_FATAL;
+ goto end;
+ }
+
+ ret = lttng_dynamic_buffer_append(
+ &local_flattened_events, element->event, sizeof(struct lttng_event));
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ for (i = 0; i < nb_events; i++) {
+ const struct event_list_element *element =
+ (const struct event_list_element *) lttng_dynamic_pointer_array_get_pointer(
+ events, i);
+ struct lttng_event *event =
+ (struct lttng_event *) (local_flattened_events.data +
+ (sizeof(struct lttng_event) * i));
+ struct lttng_event_extended *event_extended =
+ (struct lttng_event_extended *) (local_flattened_events.data +
+ local_flattened_events.size);
+ const struct lttng_userspace_probe_location *location = nullptr;
+
+ assert(element);
+
+ /* Insert struct lttng_event_extended. */
+ ret = lttng_dynamic_buffer_set_size(&local_flattened_events,
+ local_flattened_events.size +
+ sizeof(*event_extended));
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ event->extended.ptr = event_extended;
+
+ /* Insert filter expression. */
+ if (element->filter_expression) {
+ const size_t len = strlen(element->filter_expression) + 1;
+
+ event_extended->filter_expression =
+ local_flattened_events.data + local_flattened_events.size;
+ ret = lttng_dynamic_buffer_append(
+ &local_flattened_events, element->filter_expression, len);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ /* Insert exclusions. */
+ if (element->exclusions) {
+ event_extended->exclusions.count = element->exclusions->count;
+ event_extended->exclusions.strings =
+ local_flattened_events.data + local_flattened_events.size;
+
+ ret = lttng_dynamic_buffer_append(&local_flattened_events,
+ element->exclusions->names,
+ element->exclusions->count *
+ LTTNG_SYMBOL_NAME_LEN);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ /* Insert padding to align to 64-bits. */
+ ret = lttng_dynamic_buffer_set_size(&local_flattened_events,
+ lttng_align_ceil(local_flattened_events.size,
+ sizeof(uint64_t)));
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ location = lttng_event_get_userspace_probe_location(element->event);
+ if (location) {
+ event_extended->probe_location = (struct lttng_userspace_probe_location
+ *) (local_flattened_events.data +
+ local_flattened_events.size);
+ ret = lttng_userspace_probe_location_flatten(location,
+ &local_flattened_events);
+ if (ret < 0) {
+ ret_code = LTTNG_ERR_PROBE_LOCATION_INVAL;
+ goto end;
+ }
+ }
+ }
+
+ /* Don't reset local_flattened_events buffer as we return its content. */
+ *flattened_events = (struct lttng_event *) local_flattened_events.data;
+ lttng_dynamic_buffer_init(&local_flattened_events);
+ ret_code = LTTNG_OK;
+end:
+ lttng_dynamic_buffer_reset(&local_flattened_events);
+ return ret_code;
+}
+
+static enum lttng_error_code
+event_list_create_from_payload(struct lttng_payload_view *view,
+ unsigned int count,
+ struct lttng_dynamic_pointer_array *event_list)
+{
+ enum lttng_error_code ret_code;
+ int ret;
+ unsigned int i;
+ int offset = 0;
+
+ assert(view);
+ assert(event_list);
+
+ for (i = 0; i < count; i++) {
+ ssize_t event_size;
+ struct lttng_payload_view event_view =
+ lttng_payload_view_from_view(view, offset, -1);
+ struct event_list_element *element = zmalloc<event_list_element>();
+
+ if (!element) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /*
+ * Lifetime and management of the object is now bound to the
+ * array.
+ */
+ ret = lttng_dynamic_pointer_array_add_pointer(event_list, element);
+ if (ret) {
+ event_list_destructor(element);
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ /*
+ * Bytecode is not transmitted on listing in any case we do not
+ * care about it.
+ */
+ event_size = lttng_event_create_from_payload(&event_view,
+ &element->event,
+ &element->exclusions,
+ &element->filter_expression,
+ nullptr);
+ if (event_size < 0) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ offset += event_size;
+ }
+
+ if (view->buffer.size != offset) {
+ ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+ goto end;
+ }
+
+ ret_code = LTTNG_OK;
+
+end:
+ return ret_code;
+}
+
+enum lttng_error_code lttng_events_create_and_flatten_from_payload(
+ struct lttng_payload_view *payload, unsigned int count, struct lttng_event **events)
+{
+ enum lttng_error_code ret = LTTNG_OK;
+ struct lttng_dynamic_pointer_array local_events;
+
+ lttng_dynamic_pointer_array_init(&local_events, event_list_destructor);
+
+ /* Deserialize the events. */
+ {
+ struct lttng_payload_view events_view =
+ lttng_payload_view_from_view(payload, 0, -1);
+
+ ret = event_list_create_from_payload(&events_view, count, &local_events);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+ }
+
+ ret = flatten_lttng_events(&local_events, events);
+ if (ret != LTTNG_OK) {
+ goto end;
+ }
+
+end:
+ lttng_dynamic_pointer_array_reset(&local_events);
+ return ret;
+}
+
+static enum lttng_error_code
+flatten_lttng_event_fields(struct lttng_dynamic_pointer_array *event_fields,
+ struct lttng_event_field **flattened_event_fields)
+{
+ int ret, i;
+ enum lttng_error_code ret_code;
+ size_t storage_req = 0;
+ struct lttng_dynamic_buffer local_flattened_event_fields;
+ int nb_event_field;
+
+ assert(event_fields);
+ assert(flattened_event_fields);
+
+ lttng_dynamic_buffer_init(&local_flattened_event_fields);
+ nb_event_field = lttng_dynamic_pointer_array_get_count(event_fields);
+
+ /*
+ * Here even if the event field contains a `struct lttng_event` that
+ * could contain dynamic data, in reality it is not the case.
+ * Dynamic data is not present. Here the flattening is mostly a direct
+ * memcpy. This is less than ideal but this code is still better than
+ * direct usage of an unpacked lttng_event_field array.
+ */
+ storage_req += sizeof(struct lttng_event_field) * nb_event_field;
+
+ lttng_dynamic_buffer_init(&local_flattened_event_fields);
+
+ /*
+ * We must ensure that "local_flattened_event_fields" is never resized
+ * so as to preserve the validity of the flattened objects.
+ */
+ ret = lttng_dynamic_buffer_set_capacity(&local_flattened_event_fields, storage_req);
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ for (i = 0; i < nb_event_field; i++) {
+ const struct lttng_event_field *element =
+ (const struct lttng_event_field *) lttng_dynamic_pointer_array_get_pointer(
+ event_fields, i);
+
+ if (!element) {
+ ret_code = LTTNG_ERR_FATAL;
+ goto end;
+ }
+ ret = lttng_dynamic_buffer_append(
+ &local_flattened_event_fields, element, sizeof(struct lttng_event_field));
+ if (ret) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+ }
+
+ /* Don't reset local_flattened_channels buffer as we return its content. */
+ *flattened_event_fields = (struct lttng_event_field *) local_flattened_event_fields.data;
+ lttng_dynamic_buffer_init(&local_flattened_event_fields);
+ ret_code = LTTNG_OK;
+end:
+ lttng_dynamic_buffer_reset(&local_flattened_event_fields);
+ return ret_code;
+}
+
+static enum lttng_error_code
+event_field_list_create_from_payload(struct lttng_payload_view *view,
+ unsigned int count,
+ struct lttng_dynamic_pointer_array **event_field_list)
+{
+ enum lttng_error_code ret_code;
+ int ret, offset = 0;
+ unsigned int i;
+ struct lttng_dynamic_pointer_array *list = nullptr;
+
+ assert(view);
+ assert(event_field_list);
+
+ list = zmalloc<lttng_dynamic_pointer_array>();
+ if (!list) {
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ lttng_dynamic_pointer_array_init(list, free);
+
+ for (i = 0; i < count; i++) {
+ ssize_t event_field_size;
+ struct lttng_event_field *field = nullptr;
+ struct lttng_payload_view event_field_view =
+ lttng_payload_view_from_view(view, offset, -1);
+
+ event_field_size = lttng_event_field_create_from_payload(&event_field_view, &field);
+ if (event_field_size < 0) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ /* Lifetime and management of the object is now bound to the array. */
+ ret = lttng_dynamic_pointer_array_add_pointer(list, field);
+ if (ret) {
+ free(field);
+ ret_code = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ offset += event_field_size;
+ }
+
+ if (view->buffer.size != offset) {
+ ret_code = LTTNG_ERR_INVALID;
+ goto end;
+ }
+
+ *event_field_list = list;
+ list = nullptr;
+ ret_code = LTTNG_OK;
+
+end:
+ if (list) {
+ lttng_dynamic_pointer_array_reset(list);
+ free(list);
+ }
+
+ return ret_code;
+}
+
+enum lttng_error_code lttng_event_fields_create_and_flatten_from_payload(
+ struct lttng_payload_view *view, unsigned int count, struct lttng_event_field **fields)
+{
+ enum lttng_error_code ret_code;
+ struct lttng_dynamic_pointer_array *local_event_fields = nullptr;
+
+ ret_code = event_field_list_create_from_payload(view, count, &local_event_fields);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+
+ ret_code = flatten_lttng_event_fields(local_event_fields, fields);
+ if (ret_code != LTTNG_OK) {
+ goto end;
+ }
+end:
+ if (local_event_fields) {
+ lttng_dynamic_pointer_array_reset(local_event_fields);
+ free(local_event_fields);
+ }
+
+ return ret_code;
+}