/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2007 Diomidis Spinellis
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/acct.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
int readrec_forward(FILE *f, struct acctv3 *av2);
int readrec_backward(FILE *f, struct acctv3 *av2);
/*
* Reverse offsetof: return the offset of field f
* from the end of the structure s.
*/
#define roffsetof(s, f) (sizeof(s) - offsetof(s, f))
/*
* Read exactly one record of size size from stream f into ptr.
* Failure to read the complete record is considered a file format error,
* and will set errno to EFTYPE.
* Return 0 on success, EOF on end of file or error.
*/
static int
fread_record(void *ptr, size_t size, FILE *f)
{
size_t rv;
if ((rv = fread(ptr, 1, size, f)) == size)
return (0);
else if (ferror(f) || rv == 0)
return (EOF);
else {
/* Short read. */
errno = EFTYPE;
return (EOF);
}
}
/*
* Return the value of a comp_t field.
*/
static float
decode_comp(comp_t v)
{
int result, exp;
result = v & 017777;
for (exp = v >> 13; exp; exp--)
result <<= 3;
return ((double)result / AHZV1);
}
/*
* Read a v1 accounting record stored at the current
* position of stream f.
* Convert the data to the current record format.
* Return EOF on error or end-of-file.
*/
static int
readrec_v1(FILE *f, struct acctv3 *av3)
{
struct acctv1 av1;
int rv;
if ((rv = fread_record(&av1, sizeof(av1), f)) == EOF)
return (EOF);
av3->ac_zero = 0;
av3->ac_version = 3;
av3->ac_len = av3->ac_len2 = sizeof(*av3);
memcpy(av3->ac_comm, av1.ac_comm, AC_COMM_LEN);
av3->ac_utime = decode_comp(av1.ac_utime) * 1000000;
av3->ac_stime = decode_comp(av1.ac_stime) * 1000000;
av3->ac_etime = decode_comp(av1.ac_etime) * 1000000;
av3->ac_btime = av1.ac_btime;
av3->ac_uid = av1.ac_uid;
av3->ac_gid = av1.ac_gid;
av3->ac_mem = av1.ac_mem;
av3->ac_io = decode_comp(av1.ac_io);
av3->ac_tty = av1.ac_tty;
av3->ac_flagx = av1.ac_flag | ANVER;
return (0);
}
/*
* Read an v2 accounting record stored at the current
* position of stream f.
* Return EOF on error or end-of-file.
*/
static int
readrec_v2(FILE *f, struct acctv3 *av3)
{
struct acctv2 av2;
int rv;
if ((rv = fread_record(&av2, sizeof(av2), f)) == EOF)
return (EOF);
av3->ac_zero = 0;
av3->ac_version = 3;
av3->ac_len = av3->ac_len2 = sizeof(*av3);
memcpy(av3->ac_comm, av2.ac_comm, AC_COMM_LEN);
av3->ac_utime = av2.ac_utime;
av3->ac_stime = av2.ac_stime;
av3->ac_etime = av2.ac_etime;
av3->ac_btime = av2.ac_btime;
av3->ac_uid = av2.ac_uid;
av3->ac_gid = av2.ac_gid;
av3->ac_mem = av2.ac_mem;
av3->ac_io = av2.ac_io;
av3->ac_tty = av2.ac_tty;
av3->ac_flagx = av2.ac_flagx;
return (0);
}
/*
* Read an v2 accounting record stored at the current
* position of stream f.
* Return EOF on error or end-of-file.
*/
static int
readrec_v3(FILE *f, struct acctv3 *av3)
{
return (fread_record(av3, sizeof(*av3), f));
}
/*
* Read a new-style (post-v1) accounting record stored at
* the current position of stream f.
* Convert the data to the current record format.
* Return EOF on error or end-of-file.
*/
static int
readrec_vx(FILE *f, struct acctv3 *av3)
{
uint8_t magic, version;
if (fread_record(&magic, sizeof(magic), f) == EOF ||
fread_record(&version, sizeof(version), f) == EOF ||
ungetc(version, f) == EOF ||
ungetc(magic, f) == EOF)
return (EOF);
switch (version) {
case 2:
return (readrec_v2(f, av3));
case 3:
return (readrec_v3(f, av3));
/* Add handling for more versions here. */
default:
errno = EFTYPE;
return (EOF);
}
}
/*
* Read an accounting record stored at the current
* position of stream f.
* Old-format records are converted to the current record
* format.
* Return the number of records read (1 or 0 at the end-of-file),
* or EOF on error.
*/
int
readrec_forward(FILE *f, struct acctv3 *av3)
{
int magic, rv;
if ((magic = getc(f)) == EOF)
return (ferror(f) ? EOF : 0);
if (ungetc(magic, f) == EOF)
return (EOF);
if (magic != 0)
/* Old record format. */
rv = readrec_v1(f, av3);
else
/* New record formats. */
rv = readrec_vx(f, av3);
return (rv == EOF ? EOF : 1);
}
/*
* Read an accounting record ending at the current
* position of stream f.
* Old-format records are converted to the current record
* format.
* The file pointer is positioned at the beginning of the
* record read.
* Return the number of records read (1 or 0 at the end-of-file),
* or EOF on error.
*/
int
readrec_backward(FILE *f, struct acctv3 *av3)
{
off_t pos;
int c;
uint16_t len;
if ((pos = ftell(f)) == -1)
return (EOF);
if (pos == 0)
return (0);
if (fseek(f, -roffsetof(struct acctv3, ac_trailer),
SEEK_CUR) == EOF ||
(c = getc(f)) == EOF)
return (EOF);
if (c & ANVER) {
/*
* New record formats. For v2 and v3 offset from the
* end for ac_len2 should be same.
*/
if (fseeko(f, pos - roffsetof(struct acctv2, ac_len2),
SEEK_SET) == EOF ||
fread_record(&len, sizeof(len), f) == EOF ||
fseeko(f, pos - len, SEEK_SET) == EOF ||
readrec_vx(f, av3) == EOF ||
fseeko(f, pos - len, SEEK_SET) == EOF)
return (EOF);
else
return (1);
} else {
/* Old record format. */
if (fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF ||
readrec_v1(f, av3) == EOF ||
fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF)
return (EOF);
else
return (1);
}
}
