| 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.h> |
| 9 | #include <common/dynamic-buffer.h> |
| 10 | #include <common/error.h> |
| 11 | #include <assert.h> |
| 12 | |
| 13 | LTTNG_HIDDEN |
| 14 | struct lttng_buffer_view lttng_buffer_view_init( |
| 15 | const char *src, size_t offset, ptrdiff_t len) |
| 16 | { |
| 17 | struct lttng_buffer_view view = { .data = src + offset, .size = len }; |
| 18 | return view; |
| 19 | } |
| 20 | |
| 21 | LTTNG_HIDDEN |
| 22 | bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view) |
| 23 | { |
| 24 | return view && view->data && view->size > 0; |
| 25 | } |
| 26 | |
| 27 | LTTNG_HIDDEN |
| 28 | struct lttng_buffer_view lttng_buffer_view_from_view( |
| 29 | const struct lttng_buffer_view *src, size_t offset, |
| 30 | ptrdiff_t len) |
| 31 | { |
| 32 | struct lttng_buffer_view view = { .data = NULL, .size = 0 }; |
| 33 | |
| 34 | assert(src); |
| 35 | |
| 36 | if (offset > src->size) { |
| 37 | ERR("Attempt to create buffer view from another view with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd", |
| 38 | src->size, offset, len); |
| 39 | goto end; |
| 40 | } |
| 41 | |
| 42 | if (len != -1 && len > (src->size - offset)) { |
| 43 | 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", |
| 44 | src->size, offset, len); |
| 45 | goto end; |
| 46 | } |
| 47 | |
| 48 | view.data = src->data + offset; |
| 49 | view.size = len == -1 ? (src->size - offset) : len; |
| 50 | end: |
| 51 | return view; |
| 52 | } |
| 53 | |
| 54 | LTTNG_HIDDEN |
| 55 | struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer( |
| 56 | const struct lttng_dynamic_buffer *src, size_t offset, |
| 57 | ptrdiff_t len) |
| 58 | { |
| 59 | struct lttng_buffer_view view = { .data = NULL, .size = 0 }; |
| 60 | |
| 61 | assert(src); |
| 62 | |
| 63 | if (offset > src->size) { |
| 64 | 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", |
| 65 | src->size, offset, len); |
| 66 | goto end; |
| 67 | } |
| 68 | |
| 69 | if (len != -1 && len > (src->size - offset)) { |
| 70 | 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", |
| 71 | src->size, offset, 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 | LTTNG_HIDDEN |
| 82 | bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf, |
| 83 | const char *str, |
| 84 | size_t len_with_null_terminator) |
| 85 | { |
| 86 | const char *past_buf_end; |
| 87 | size_t max_str_len_with_null_terminator; |
| 88 | size_t str_len; |
| 89 | bool ret; |
| 90 | |
| 91 | past_buf_end = buf->data + buf->size; |
| 92 | |
| 93 | /* Is the start of the string in the buffer view? */ |
| 94 | if (str < buf->data || str >= past_buf_end) { |
| 95 | ret = false; |
| 96 | goto end; |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Max length the string could have to fit in the buffer, including |
| 101 | * NULL terminator. |
| 102 | */ |
| 103 | max_str_len_with_null_terminator = past_buf_end - str; |
| 104 | |
| 105 | /* Could the string even fit in the buffer? */ |
| 106 | if (len_with_null_terminator > max_str_len_with_null_terminator) { |
| 107 | ret = false; |
| 108 | goto end; |
| 109 | } |
| 110 | |
| 111 | str_len = lttng_strnlen(str, max_str_len_with_null_terminator); |
| 112 | if (str_len != (len_with_null_terminator - 1)) { |
| 113 | ret = false; |
| 114 | goto end; |
| 115 | } |
| 116 | |
| 117 | ret = true; |
| 118 | |
| 119 | end: |
| 120 | return ret; |
| 121 | } |