buffer-view: improve logging on creation failure

[lttng-tools.git] / src / common / buffer-view.c

diff --git a/src/common/buffer-view.c b/src/common/buffer-view.c
index 8ff1539919a8f7140a7a2ac25780a6fcf323e5ea..04bd1ca354f5555b4b78063ba523684cd93b52c2 100644 (file)
--- a/src/common/buffer-view.c
+++ b/src/common/buffer-view.c
@@ -1,26 +1,30 @@
 /*
- * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
- * This program 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.
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
- * 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 Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser 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
  */
 
 #include <common/buffer-view.h>
 #include <common/dynamic-buffer.h>
-#include <common/macros.h>
 #include <common/error.h>
 #include <assert.h>
 
+LTTNG_HIDDEN
+struct lttng_buffer_view lttng_buffer_view_init(
+               const char *src, size_t offset, ptrdiff_t len)
+{
+       struct lttng_buffer_view view = { .data = src + offset, .size = len };
+       return view;
+}
+
+LTTNG_HIDDEN
+bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view)
+{
+       return view && view->data && view->size > 0;
+}
+
+LTTNG_HIDDEN
 struct lttng_buffer_view lttng_buffer_view_from_view(
                const struct lttng_buffer_view *src, size_t offset,
                ptrdiff_t len)
@@ -30,12 +34,14 @@ struct lttng_buffer_view lttng_buffer_view_from_view(
        assert(src);
 
        if (offset > src->size) {
-               ERR("Attempt to create buffer view with invalid offset");
+               ERR("Attempt to create buffer view from another view with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd",
+                               src->size, offset, len);
                goto end;
        }
 
        if (len != -1 && len > (src->size - offset)) {
-               ERR("Attempt to create buffer view with invalid length");
+               ERR("Attempt to create buffer view from another view with invalid length (length > space left after offset in source): source size = %zu, offset in source = %zu, length = %zd",
+                               src->size, offset, len);
                goto end;
        }
 
@@ -45,6 +51,7 @@ end:
        return view;
 }
 
+LTTNG_HIDDEN
 struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
                const struct lttng_dynamic_buffer *src, size_t offset,
                ptrdiff_t len)
@@ -54,12 +61,14 @@ struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
        assert(src);
 
        if (offset > src->size) {
-               ERR("Attempt to create buffer view with invalid offset");
+               ERR("Attempt to create buffer view from a dynamic buffer with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd",
+                               src->size, offset, len);
                goto end;
        }
 
        if (len != -1 && len > (src->size - offset)) {
-               ERR("Attempt to create buffer view with invalid length");
+               ERR("Attempt to create buffer view from a dynamic buffer with invalid length (length > space left after offset in source): source size = %zu, offset in source = %zu, length = %zd",
+                               src->size, offset, len);
                goto end;
        }
 
@@ -68,3 +77,45 @@ struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
 end:
        return view;
 }
+
+LTTNG_HIDDEN
+bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf,
+               const char *str,
+               size_t len_with_null_terminator)
+{
+       const char *past_buf_end;
+       size_t max_str_len_with_null_terminator;
+       size_t str_len;
+       bool ret;
+
+       past_buf_end = buf->data + buf->size;
+
+       /* Is the start of the string in the buffer view? */
+       if (str < buf->data || str >= past_buf_end) {
+               ret = false;
+               goto end;
+       }
+
+       /*
+        * Max length the string could have to fit in the buffer, including
+        * NULL terminator.
+        */
+       max_str_len_with_null_terminator = past_buf_end - str;
+
+       /* Could the string even fit in the buffer? */
+       if (len_with_null_terminator > max_str_len_with_null_terminator) {
+               ret = false;
+               goto end;
+       }
+
+       str_len = lttng_strnlen(str, max_str_len_with_null_terminator);
+       if (str_len != (len_with_null_terminator - 1)) {
+               ret = false;
+               goto end;
+       }
+
+       ret = true;
+
+end:
+       return ret;
+}