| 1 | /* |
| 2 | * Copyright (C) 2023 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #include "file-descriptor.hpp" |
| 9 | |
| 10 | #include <common/error.hpp> |
| 11 | #include <common/exception.hpp> |
| 12 | #include <common/format.hpp> |
| 13 | #include <common/readwrite.hpp> |
| 14 | |
| 15 | #include <algorithm> |
| 16 | #include <limits> |
| 17 | #include <unistd.h> |
| 18 | |
| 19 | namespace { |
| 20 | bool is_valid_fd(int fd) |
| 21 | { |
| 22 | return fd >= 0; |
| 23 | } |
| 24 | } // anonymous namespace |
| 25 | |
| 26 | lttng::file_descriptor::file_descriptor() noexcept |
| 27 | { |
| 28 | } |
| 29 | |
| 30 | lttng::file_descriptor::file_descriptor(int raw_fd) noexcept : _raw_fd{ raw_fd } |
| 31 | { |
| 32 | LTTNG_ASSERT(is_valid_fd(_raw_fd)); |
| 33 | } |
| 34 | |
| 35 | lttng::file_descriptor::file_descriptor(lttng::file_descriptor&& other) noexcept |
| 36 | { |
| 37 | std::swap(_raw_fd, other._raw_fd); |
| 38 | } |
| 39 | |
| 40 | lttng::file_descriptor& lttng::file_descriptor::operator=(lttng::file_descriptor&& other) noexcept |
| 41 | { |
| 42 | _cleanup(); |
| 43 | std::swap(_raw_fd, other._raw_fd); |
| 44 | return *this; |
| 45 | } |
| 46 | |
| 47 | lttng::file_descriptor::~file_descriptor() noexcept |
| 48 | { |
| 49 | _cleanup(); |
| 50 | } |
| 51 | |
| 52 | int lttng::file_descriptor::fd() const noexcept |
| 53 | { |
| 54 | LTTNG_ASSERT(is_valid_fd(_raw_fd)); |
| 55 | return _raw_fd; |
| 56 | } |
| 57 | |
| 58 | void lttng::file_descriptor::_cleanup() noexcept |
| 59 | { |
| 60 | if (!is_valid_fd(_raw_fd)) { |
| 61 | return; |
| 62 | } |
| 63 | |
| 64 | const auto ret = ::close(_raw_fd); |
| 65 | |
| 66 | _raw_fd = -1; |
| 67 | if (ret) { |
| 68 | PERROR("Failed to close file descriptor: fd=%i", _raw_fd); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | void lttng::file_descriptor::write(const void *buffer, std::size_t size) |
| 73 | { |
| 74 | /* |
| 75 | * This is a limitation of the internal helper that is not a problem in practice for the |
| 76 | * moment. |
| 77 | */ |
| 78 | using lttng_write_return_type = decltype(lttng_write( |
| 79 | std::declval<int>(), std::declval<const void *>(), std::declval<size_t>())); |
| 80 | constexpr auto max_supported_write_size = |
| 81 | std::numeric_limits<lttng_write_return_type>::max(); |
| 82 | |
| 83 | if (size > max_supported_write_size) { |
| 84 | LTTNG_THROW_UNSUPPORTED_ERROR(fmt::format( |
| 85 | "Write size exceeds the maximal supported value of lttng_write: write_size={}, maximal_write_size={}", |
| 86 | size, |
| 87 | max_supported_write_size)); |
| 88 | } |
| 89 | |
| 90 | const auto write_ret = lttng_write(fd(), buffer, size); |
| 91 | if (write_ret < 0 || static_cast<std::size_t>(write_ret) != size) { |
| 92 | LTTNG_THROW_POSIX(fmt::format("Failed to write to file descriptor: fd={}", fd()), |
| 93 | errno); |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | void lttng::file_descriptor::read(void *buffer, std::size_t size) |
| 98 | { |
| 99 | /* |
| 100 | * This is a limitation of the internal helper that is not a problem in practice for the |
| 101 | * moment. |
| 102 | */ |
| 103 | using lttng_read_return_type = decltype(lttng_read( |
| 104 | std::declval<int>(), std::declval<void *>(), std::declval<size_t>())); |
| 105 | constexpr auto max_supported_read_size = std::numeric_limits<lttng_read_return_type>::max(); |
| 106 | |
| 107 | if (size > max_supported_read_size) { |
| 108 | LTTNG_THROW_UNSUPPORTED_ERROR(fmt::format( |
| 109 | "Read size exceeds the maximal supported value of lttng_read: read_size={}, maximal_read_size={}", |
| 110 | size, |
| 111 | max_supported_read_size)); |
| 112 | } |
| 113 | |
| 114 | const auto read_ret = lttng_read(fd(), buffer, size); |
| 115 | if (read_ret < 0 || static_cast<std::size_t>(read_ret) != size) { |
| 116 | LTTNG_THROW_POSIX(fmt::format("Failed to read from file descriptor: fd={}", fd()), |
| 117 | errno); |
| 118 | } |
| 119 | } |