sudo/lib/iolog/iolog_read.c

80 lines
2.1 KiB
C

/*
* SPDX-License-Identifier: ISC
*
* Copyright (c) 2009-2021 Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <stdio.h>
#ifdef HAVE_STDBOOL_H
# include <stdbool.h>
#else
# include <compat/stdbool.h>
#endif
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <time.h>
#include <sudo_compat.h>
#include <sudo_debug.h>
#include <sudo_iolog.h>
/*
* Read from a (possibly compressed) I/O log file.
*/
ssize_t
iolog_read(struct iolog_file *iol, void *buf, size_t nbytes,
const char **errstr)
{
ssize_t nread;
debug_decl(iolog_read, SUDO_DEBUG_UTIL);
if (nbytes > UINT_MAX || nbytes > SSIZE_MAX) { // -V590
errno = EINVAL;
if (errstr != NULL)
*errstr = strerror(errno);
debug_return_ssize_t(-1);
}
#ifdef HAVE_ZLIB_H
if (iol->compressed) {
if ((nread = gzread(iol->fd.g, buf, (unsigned int)nbytes)) == -1) {
if (errstr != NULL) {
int errnum;
*errstr = gzerror(iol->fd.g, &errnum);
if (errnum == Z_ERRNO)
*errstr = strerror(errno);
}
}
} else
#endif
{
nread = (ssize_t)fread(buf, 1, nbytes, iol->fd.f);
if (nread <= 0 && ferror(iol->fd.f)) {
nread = -1;
if (errstr != NULL)
*errstr = strerror(errno);
}
}
debug_return_ssize_t(nread);
}