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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
commit | 1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5 (patch) | |
tree | 6cf8220b628ebd2ccfc1375dd6516c6996e9abcc /lib/utils_io.c | |
parent | Initial commit. (diff) | |
download | cryptsetup-upstream.tar.xz cryptsetup-upstream.zip |
Adding upstream version 2:2.6.1.upstream/2%2.6.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/utils_io.c | 299 |
1 files changed, 299 insertions, 0 deletions
diff --git a/lib/utils_io.c b/lib/utils_io.c new file mode 100644 index 0000000..a5bc501 --- /dev/null +++ b/lib/utils_io.c @@ -0,0 +1,299 @@ +/* + * utils - miscellaneous I/O utilities for cryptsetup + * + * Copyright (C) 2004 Jana Saout <jana@saout.de> + * Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org> + * Copyright (C) 2009-2023 Red Hat, Inc. All rights reserved. + * Copyright (C) 2009-2023 Milan Broz + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * 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 General Public License for more details. + * + * You should have received a copy of the GNU 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 <errno.h> +#include <string.h> +#include <stdlib.h> +#include <stdint.h> +#include <unistd.h> + +#include "utils_io.h" + +/* coverity[ -taint_source : arg-1 ] */ +static ssize_t _read_buffer(int fd, void *buf, size_t length, volatile int *quit) +{ + size_t read_size = 0; + ssize_t r; + + if (fd < 0 || !buf) + return -EINVAL; + + do { + r = read(fd, buf, length - read_size); + if (r == -1 && errno != EINTR) + return r; + if (r > 0) { + read_size += (size_t)r; + buf = (uint8_t*)buf + r; + } + if (r == 0 || (quit && *quit)) + return (ssize_t)read_size; + } while (read_size != length); + + return (ssize_t)length; +} + +ssize_t read_buffer(int fd, void *buf, size_t length) +{ + return _read_buffer(fd, buf, length, NULL); +} + +ssize_t read_buffer_intr(int fd, void *buf, size_t length, volatile int *quit) +{ + return _read_buffer(fd, buf, length, quit); +} + +static ssize_t _write_buffer(int fd, const void *buf, size_t length, volatile int *quit) +{ + size_t write_size = 0; + ssize_t w; + + if (fd < 0 || !buf || !length) + return -EINVAL; + + do { + w = write(fd, buf, length - write_size); + if (w < 0 && errno != EINTR) + return w; + if (w > 0) { + write_size += (size_t) w; + buf = (const uint8_t*)buf + w; + } + if (w == 0 || (quit && *quit)) + return (ssize_t)write_size; + } while (write_size != length); + + return (ssize_t)write_size; +} + +ssize_t write_buffer(int fd, const void *buf, size_t length) +{ + return _write_buffer(fd, buf, length, NULL); +} + +ssize_t write_buffer_intr(int fd, const void *buf, size_t length, volatile int *quit) +{ + return _write_buffer(fd, buf, length, quit); +} + +ssize_t write_blockwise(int fd, size_t bsize, size_t alignment, + void *orig_buf, size_t length) +{ + void *hangover_buf = NULL, *buf = NULL; + size_t hangover, solid; + ssize_t r, ret = -1; + + if (fd == -1 || !orig_buf || !bsize || !alignment) + return -1; + + hangover = length % bsize; + solid = length - hangover; + + if ((size_t)orig_buf & (alignment - 1)) { + if (posix_memalign(&buf, alignment, length)) + return -1; + memcpy(buf, orig_buf, length); + } else + buf = orig_buf; + + if (solid) { + r = write_buffer(fd, buf, solid); + if (r < 0 || r != (ssize_t)solid) + goto out; + } + + if (hangover) { + if (posix_memalign(&hangover_buf, alignment, bsize)) + goto out; + memset(hangover_buf, 0, bsize); + + r = read_buffer(fd, hangover_buf, bsize); + if (r < 0) + goto out; + + if (lseek(fd, -(off_t)r, SEEK_CUR) < 0) + goto out; + + memcpy(hangover_buf, (char*)buf + solid, hangover); + + r = write_buffer(fd, hangover_buf, bsize); + if (r < 0 || r < (ssize_t)hangover) + goto out; + } + ret = length; +out: + free(hangover_buf); + if (buf != orig_buf) + free(buf); + return ret; +} + +ssize_t read_blockwise(int fd, size_t bsize, size_t alignment, + void *orig_buf, size_t length) +{ + void *hangover_buf = NULL, *buf = NULL; + size_t hangover, solid; + ssize_t r, ret = -1; + + if (fd == -1 || !orig_buf || !bsize || !alignment) + return -1; + + hangover = length % bsize; + solid = length - hangover; + + if ((size_t)orig_buf & (alignment - 1)) { + if (posix_memalign(&buf, alignment, length)) + return -1; + } else + buf = orig_buf; + + r = read_buffer(fd, buf, solid); + if (r < 0 || r != (ssize_t)solid) + goto out; + + if (hangover) { + if (posix_memalign(&hangover_buf, alignment, bsize)) + goto out; + r = read_buffer(fd, hangover_buf, bsize); + if (r < 0 || r < (ssize_t)hangover) + goto out; + + memcpy((char *)buf + solid, hangover_buf, hangover); + } + ret = length; +out: + free(hangover_buf); + if (buf != orig_buf) { + if (ret != -1) + memcpy(orig_buf, buf, length); + free(buf); + } + return ret; +} + +/* + * Combines llseek with blockwise write. write_blockwise can already deal with short writes + * but we also need a function to deal with short writes at the start. But this information + * is implicitly included in the read/write offset, which can not be set to non-aligned + * boundaries. Hence, we combine llseek with write. + */ +ssize_t write_lseek_blockwise(int fd, size_t bsize, size_t alignment, + void *buf, size_t length, off_t offset) +{ + void *frontPadBuf = NULL; + size_t frontHang, innerCount = 0; + ssize_t r, ret = -1; + + if (fd == -1 || !buf || !bsize || !alignment) + return -1; + + if (offset < 0) + offset = lseek(fd, offset, SEEK_END); + + if (offset < 0) + return -1; + + frontHang = offset % bsize; + + if (lseek(fd, offset - frontHang, SEEK_SET) < 0) + return -1; + + if (frontHang && length) { + if (posix_memalign(&frontPadBuf, alignment, bsize)) + return -1; + + innerCount = bsize - frontHang; + if (innerCount > length) + innerCount = length; + + r = read_buffer(fd, frontPadBuf, bsize); + if (r < 0 || r < (ssize_t)(frontHang + innerCount)) + goto out; + + memcpy((char*)frontPadBuf + frontHang, buf, innerCount); + + if (lseek(fd, offset - frontHang, SEEK_SET) < 0) + goto out; + + r = write_buffer(fd, frontPadBuf, bsize); + if (r < 0 || r != (ssize_t)bsize) + goto out; + + buf = (char*)buf + innerCount; + length -= innerCount; + } + + ret = length ? write_blockwise(fd, bsize, alignment, buf, length) : 0; + if (ret >= 0) + ret += innerCount; +out: + free(frontPadBuf); + return ret; +} + +ssize_t read_lseek_blockwise(int fd, size_t bsize, size_t alignment, + void *buf, size_t length, off_t offset) +{ + void *frontPadBuf = NULL; + size_t frontHang, innerCount = 0; + ssize_t r, ret = -1; + + if (fd == -1 || !buf || bsize <= 0) + return -1; + + if (offset < 0) + offset = lseek(fd, offset, SEEK_END); + + if (offset < 0) + return -1; + + frontHang = offset % bsize; + + if (lseek(fd, offset - frontHang, SEEK_SET) < 0) + return -1; + + if (frontHang && length) { + if (posix_memalign(&frontPadBuf, alignment, bsize)) + return -1; + + innerCount = bsize - frontHang; + if (innerCount > length) + innerCount = length; + + r = read_buffer(fd, frontPadBuf, bsize); + if (r < 0 || r < (ssize_t)(frontHang + innerCount)) + goto out; + + memcpy(buf, (char*)frontPadBuf + frontHang, innerCount); + + buf = (char*)buf + innerCount; + length -= innerCount; + } + + ret = read_blockwise(fd, bsize, alignment, buf, length); + if (ret >= 0) + ret += innerCount; +out: + free(frontPadBuf); + return ret; +} |