| 1 | /* |
| 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include <common/buffer-view.hpp> |
| 9 | #include <common/dynamic-buffer.hpp> |
| 10 | #include <common/error.hpp> |
| 11 | |
| 12 | struct lttng_buffer_view lttng_buffer_view_init(const char *src, size_t offset, ptrdiff_t len) |
| 13 | { |
| 14 | struct lttng_buffer_view view = { .data = src + offset, .size = (size_t) len }; |
| 15 | return view; |
| 16 | } |
| 17 | |
| 18 | bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view) |
| 19 | { |
| 20 | return view && view->data && view->size > 0; |
| 21 | } |
| 22 | |
| 23 | struct lttng_buffer_view |
| 24 | lttng_buffer_view_from_view(const struct lttng_buffer_view *src, size_t offset, ptrdiff_t len) |
| 25 | { |
| 26 | struct lttng_buffer_view view = { .data = nullptr, .size = 0 }; |
| 27 | |
| 28 | LTTNG_ASSERT(src); |
| 29 | |
| 30 | if (offset > src->size) { |
| 31 | ERR("Attempt to create buffer view from another view with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd", |
| 32 | src->size, |
| 33 | offset, |
| 34 | len); |
| 35 | goto end; |
| 36 | } |
| 37 | |
| 38 | if (len != -1 && len > (src->size - offset)) { |
| 39 | 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", |
| 40 | src->size, |
| 41 | offset, |
| 42 | len); |
| 43 | goto end; |
| 44 | } |
| 45 | |
| 46 | view.data = src->data + offset; |
| 47 | view.size = len == -1 ? (src->size - offset) : len; |
| 48 | end: |
| 49 | return view; |
| 50 | } |
| 51 | |
| 52 | struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer( |
| 53 | const struct lttng_dynamic_buffer *src, size_t offset, ptrdiff_t len) |
| 54 | { |
| 55 | struct lttng_buffer_view view = { .data = nullptr, .size = 0 }; |
| 56 | |
| 57 | LTTNG_ASSERT(src); |
| 58 | |
| 59 | if (offset > src->size) { |
| 60 | 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", |
| 61 | src->size, |
| 62 | offset, |
| 63 | len); |
| 64 | goto end; |
| 65 | } |
| 66 | |
| 67 | if (len != -1 && len > (src->size - offset)) { |
| 68 | 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", |
| 69 | src->size, |
| 70 | offset, |
| 71 | len); |
| 72 | goto end; |
| 73 | } |
| 74 | |
| 75 | view.data = src->data + offset; |
| 76 | view.size = len == -1 ? (src->size - offset) : len; |
| 77 | end: |
| 78 | return view; |
| 79 | } |
| 80 | |
| 81 | bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf, |
| 82 | const char *str, |
| 83 | size_t len_with_null_terminator) |
| 84 | { |
| 85 | const char *past_buf_end; |
| 86 | size_t max_str_len_with_null_terminator; |
| 87 | size_t str_len; |
| 88 | bool ret; |
| 89 | |
| 90 | past_buf_end = buf->data + buf->size; |
| 91 | |
| 92 | /* Is the start of the string in the buffer view? */ |
| 93 | if (str < buf->data || str >= past_buf_end) { |
| 94 | ret = false; |
| 95 | goto end; |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | * Max length the string could have to fit in the buffer, including |
| 100 | * NULL terminator. |
| 101 | */ |
| 102 | max_str_len_with_null_terminator = past_buf_end - str; |
| 103 | |
| 104 | /* Could the string even fit in the buffer? */ |
| 105 | if (len_with_null_terminator > max_str_len_with_null_terminator) { |
| 106 | ret = false; |
| 107 | goto end; |
| 108 | } |
| 109 | |
| 110 | str_len = lttng_strnlen(str, max_str_len_with_null_terminator); |
| 111 | if (str_len != (len_with_null_terminator - 1)) { |
| 112 | ret = false; |
| 113 | goto end; |
| 114 | } |
| 115 | |
| 116 | ret = true; |
| 117 | |
| 118 | end: |
| 119 | return ret; |
| 120 | } |