1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2007 Diomidis Spinellis
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30 #include <sys/cdefs.h>
31 #include <sys/param.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <sys/acct.h>
35
36 #include <errno.h>
37 #include <stddef.h>
38 #include <stdio.h>
39 #include <string.h>
40
41 int readrec_forward(FILE *f, struct acctv3 *av2);
42 int readrec_backward(FILE *f, struct acctv3 *av2);
43
44 /*
45 * Reverse offsetof: return the offset of field f
46 * from the end of the structure s.
47 */
48 #define roffsetof(s, f) (sizeof(s) - offsetof(s, f))
49
50 /*
51 * Read exactly one record of size size from stream f into ptr.
52 * Failure to read the complete record is considered a file format error,
53 * and will set errno to EFTYPE.
54 * Return 0 on success, EOF on end of file or error.
55 */
56 static int
fread_record(void * ptr,size_t size,FILE * f)57 fread_record(void *ptr, size_t size, FILE *f)
58 {
59 size_t rv;
60
61 if ((rv = fread(ptr, 1, size, f)) == size)
62 return (0);
63 else if (ferror(f) || rv == 0)
64 return (EOF);
65 else {
66 /* Short read. */
67 errno = EFTYPE;
68 return (EOF);
69 }
70 }
71
72 /*
73 * Return the value of a comp_t field.
74 */
75 static float
decode_comp(comp_t v)76 decode_comp(comp_t v)
77 {
78 int result, exp;
79
80 result = v & 017777;
81 for (exp = v >> 13; exp; exp--)
82 result <<= 3;
83 return ((double)result / AHZV1);
84 }
85
86 /*
87 * Read a v1 accounting record stored at the current
88 * position of stream f.
89 * Convert the data to the current record format.
90 * Return EOF on error or end-of-file.
91 */
92 static int
readrec_v1(FILE * f,struct acctv3 * av3)93 readrec_v1(FILE *f, struct acctv3 *av3)
94 {
95 struct acctv1 av1;
96 int rv;
97
98 if ((rv = fread_record(&av1, sizeof(av1), f)) == EOF)
99 return (EOF);
100 av3->ac_zero = 0;
101 av3->ac_version = 3;
102 av3->ac_len = av3->ac_len2 = sizeof(*av3);
103 memcpy(av3->ac_comm, av1.ac_comm, AC_COMM_LEN);
104 av3->ac_utime = decode_comp(av1.ac_utime) * 1000000;
105 av3->ac_stime = decode_comp(av1.ac_stime) * 1000000;
106 av3->ac_etime = decode_comp(av1.ac_etime) * 1000000;
107 av3->ac_btime = av1.ac_btime;
108 av3->ac_uid = av1.ac_uid;
109 av3->ac_gid = av1.ac_gid;
110 av3->ac_mem = av1.ac_mem;
111 av3->ac_io = decode_comp(av1.ac_io);
112 av3->ac_tty = av1.ac_tty;
113 av3->ac_flagx = av1.ac_flag | ANVER;
114 return (0);
115 }
116
117 /*
118 * Read an v2 accounting record stored at the current
119 * position of stream f.
120 * Return EOF on error or end-of-file.
121 */
122 static int
readrec_v2(FILE * f,struct acctv3 * av3)123 readrec_v2(FILE *f, struct acctv3 *av3)
124 {
125 struct acctv2 av2;
126 int rv;
127
128 if ((rv = fread_record(&av2, sizeof(av2), f)) == EOF)
129 return (EOF);
130 av3->ac_zero = 0;
131 av3->ac_version = 3;
132 av3->ac_len = av3->ac_len2 = sizeof(*av3);
133 memcpy(av3->ac_comm, av2.ac_comm, AC_COMM_LEN);
134 av3->ac_utime = av2.ac_utime;
135 av3->ac_stime = av2.ac_stime;
136 av3->ac_etime = av2.ac_etime;
137 av3->ac_btime = av2.ac_btime;
138 av3->ac_uid = av2.ac_uid;
139 av3->ac_gid = av2.ac_gid;
140 av3->ac_mem = av2.ac_mem;
141 av3->ac_io = av2.ac_io;
142 av3->ac_tty = av2.ac_tty;
143 av3->ac_flagx = av2.ac_flagx;
144 return (0);
145 }
146
147 /*
148 * Read an v2 accounting record stored at the current
149 * position of stream f.
150 * Return EOF on error or end-of-file.
151 */
152 static int
readrec_v3(FILE * f,struct acctv3 * av3)153 readrec_v3(FILE *f, struct acctv3 *av3)
154 {
155
156 return (fread_record(av3, sizeof(*av3), f));
157 }
158
159 /*
160 * Read a new-style (post-v1) accounting record stored at
161 * the current position of stream f.
162 * Convert the data to the current record format.
163 * Return EOF on error or end-of-file.
164 */
165 static int
readrec_vx(FILE * f,struct acctv3 * av3)166 readrec_vx(FILE *f, struct acctv3 *av3)
167 {
168 uint8_t magic, version;
169
170 if (fread_record(&magic, sizeof(magic), f) == EOF ||
171 fread_record(&version, sizeof(version), f) == EOF ||
172 ungetc(version, f) == EOF ||
173 ungetc(magic, f) == EOF)
174 return (EOF);
175 switch (version) {
176 case 2:
177 return (readrec_v2(f, av3));
178 case 3:
179 return (readrec_v3(f, av3));
180
181 /* Add handling for more versions here. */
182
183 default:
184 errno = EFTYPE;
185 return (EOF);
186 }
187 }
188
189 /*
190 * Read an accounting record stored at the current
191 * position of stream f.
192 * Old-format records are converted to the current record
193 * format.
194 * Return the number of records read (1 or 0 at the end-of-file),
195 * or EOF on error.
196 */
197 int
readrec_forward(FILE * f,struct acctv3 * av3)198 readrec_forward(FILE *f, struct acctv3 *av3)
199 {
200 int magic, rv;
201
202 if ((magic = getc(f)) == EOF)
203 return (ferror(f) ? EOF : 0);
204 if (ungetc(magic, f) == EOF)
205 return (EOF);
206 if (magic != 0)
207 /* Old record format. */
208 rv = readrec_v1(f, av3);
209 else
210 /* New record formats. */
211 rv = readrec_vx(f, av3);
212 return (rv == EOF ? EOF : 1);
213 }
214
215 /*
216 * Read an accounting record ending at the current
217 * position of stream f.
218 * Old-format records are converted to the current record
219 * format.
220 * The file pointer is positioned at the beginning of the
221 * record read.
222 * Return the number of records read (1 or 0 at the end-of-file),
223 * or EOF on error.
224 */
225 int
readrec_backward(FILE * f,struct acctv3 * av3)226 readrec_backward(FILE *f, struct acctv3 *av3)
227 {
228 off_t pos;
229 int c;
230 uint16_t len;
231
232 if ((pos = ftell(f)) == -1)
233 return (EOF);
234 if (pos == 0)
235 return (0);
236 if (fseek(f, -roffsetof(struct acctv3, ac_trailer),
237 SEEK_CUR) == EOF ||
238 (c = getc(f)) == EOF)
239 return (EOF);
240 if (c & ANVER) {
241 /*
242 * New record formats. For v2 and v3 offset from the
243 * end for ac_len2 should be same.
244 */
245 if (fseeko(f, pos - roffsetof(struct acctv2, ac_len2),
246 SEEK_SET) == EOF ||
247 fread_record(&len, sizeof(len), f) == EOF ||
248 fseeko(f, pos - len, SEEK_SET) == EOF ||
249 readrec_vx(f, av3) == EOF ||
250 fseeko(f, pos - len, SEEK_SET) == EOF)
251 return (EOF);
252 else
253 return (1);
254 } else {
255 /* Old record format. */
256 if (fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF ||
257 readrec_v1(f, av3) == EOF ||
258 fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF)
259 return (EOF);
260 else
261 return (1);
262 }
263 }
264