lttng-ctl: add userspace probe location interface

[lttng-tools.git] / include / lttng / userspace-probe-internal.h

diff --git a/include/lttng/userspace-probe-internal.h b/include/lttng/userspace-probe-internal.h
new file mode 100644 (file)
index 0000000..3e8eecb
--- /dev/null
+++ b/include/lttng/userspace-probe-internal.h
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2018 - Francis Deslauriers <francis.deslauriers@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef LTTNG_USERSPACE_PROBE_INTERNAL_H
+#define LTTNG_USERSPACE_PROBE_INTERNAL_H
+
+#include <lttng/userspace-probe.h>
+#include <common/macros.h>
+#include <common/dynamic-buffer.h>
+#include <common/buffer-view.h>
+
+/*
+ * No elf-specific comm structure is defined since no elf-specific payload is
+ * currently needed.
+ */
+struct lttng_userspace_probe_location_lookup_method_comm {
+       /* enum lttng_userspace_probe_location_lookup_method_type */
+       int8_t type;
+       /* type-specific payload */
+       char payload[];
+};
+
+/* Common ancestor of all userspace probe location lookup methods. */
+struct lttng_userspace_probe_location_lookup_method {
+       enum lttng_userspace_probe_location_lookup_method_type type;
+};
+
+struct lttng_userspace_probe_location_lookup_method_elf {
+       struct lttng_userspace_probe_location_lookup_method parent;
+};
+
+struct lttng_userspace_probe_location_comm {
+       /* enum lttng_userspace_probe_location_type */
+       int8_t type;
+       /*
+        * Payload is composed of, in that order,
+        *   - type-specific payload
+        *   - struct lttng_userspace_probe_location_lookup_method_comm
+        */
+       char payload[];
+};
+
+struct lttng_userspace_probe_location_function_comm {
+       /* Both lengths include the trailing \0. */
+       uint32_t function_name_len;
+       uint32_t binary_path_len;
+       /*
+        * Payload is composed of, in that order,
+        *   - function name (with trailing \0),
+        *   - absolute binary path (with trailing \0)
+        */
+       char payload[];
+} LTTNG_PACKED;
+
+/* Common ancestor of all userspace probe locations. */
+struct lttng_userspace_probe_location {
+       enum lttng_userspace_probe_location_type type;
+       struct lttng_userspace_probe_location_lookup_method *lookup_method;
+};
+
+struct lttng_userspace_probe_location_function {
+       struct lttng_userspace_probe_location parent;
+       char *function_name;
+       char *binary_path;
+       /*
+        * binary_fd is a file descriptor to the executable file. It's open
+        * early on to keep the backing inode valid over the course of the
+        * intrumentation and use. It prevents deletion and reuse races.
+        * Set to -1 if not open.
+        */
+       int binary_fd;
+};
+
+LTTNG_HIDDEN
+int lttng_userspace_probe_location_serialize(
+               const struct lttng_userspace_probe_location *location,
+               struct lttng_dynamic_buffer *buffer,
+               int *binary_fd);
+
+LTTNG_HIDDEN
+int lttng_userspace_probe_location_create_from_buffer(
+               const struct lttng_buffer_view *buffer,
+               struct lttng_userspace_probe_location **probe_location);
+
+LTTNG_HIDDEN
+int lttng_userspace_probe_location_function_set_binary_fd(
+               struct lttng_userspace_probe_location *location, int binary_fd);
+
+/*
+ * Returns a version of the location that is serialized to a contiguous region
+ * of memory. Pass NULL to buffer to only get the storage requirement of the
+ * flattened userspace probe location.
+ */
+LTTNG_HIDDEN
+int lttng_userspace_probe_location_flatten(
+               const struct lttng_userspace_probe_location *location,
+               struct lttng_dynamic_buffer *buffer);
+
+#endif /* LTTNG_USERSPACE_PROBE_INTERNAL_H */