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/param.h>
31 #include <sys/stat.h>
32 #include <sys/types.h>
33 #include <sys/acct.h>
34
35 #include <errno.h>
36 #include <stddef.h>
37 #include <stdio.h>
38 #include <string.h>
39
40 int readrec_forward(FILE *f, struct acctv3 *av2);
41 int readrec_backward(FILE *f, struct acctv3 *av2);
42
43 /*
44 * Reverse offsetof: return the offset of field f
45 * from the end of the structure s.
46 */
47 #define roffsetof(s, f) (sizeof(s) - offsetof(s, f))
48
49 /*
50 * Read exactly one record of size size from stream f into ptr.
51 * Failure to read the complete record is considered a file format error,
52 * and will set errno to EFTYPE.
53 * Return 0 on success, EOF on end of file or error.
54 */
55 static int
fread_record(void * ptr,size_t size,FILE * f)56 fread_record(void *ptr, size_t size, FILE *f)
57 {
58 size_t rv;
59
60 if ((rv = fread(ptr, 1, size, f)) == size)
61 return (0);
62 else if (ferror(f) || rv == 0)
63 return (EOF);
64 else {
65 /* Short read. */
66 errno = EFTYPE;
67 return (EOF);
68 }
69 }
70
71 /*
72 * Return the value of a comp_t field.
73 */
74 static float
decode_comp(comp_t v)75 decode_comp(comp_t v)
76 {
77 int result, exp;
78
79 result = v & 017777;
80 for (exp = v >> 13; exp; exp--)
81 result <<= 3;
82 return ((double)result / AHZV1);
83 }
84
85 /*
86 * Read a v1 accounting record stored at the current
87 * position of stream f.
88 * Convert the data to the current record format.
89 * Return EOF on error or end-of-file.
90 */
91 static int
readrec_v1(FILE * f,struct acctv3 * av3)92 readrec_v1(FILE *f, struct acctv3 *av3)
93 {
94 struct acctv1 av1;
95 int rv;
96
97 if ((rv = fread_record(&av1, sizeof(av1), f)) == EOF)
98 return (EOF);
99 av3->ac_zero = 0;
100 av3->ac_version = 3;
101 av3->ac_len = av3->ac_len2 = sizeof(*av3);
102 memcpy(av3->ac_comm, av1.ac_comm, AC_COMM_LEN);
103 av3->ac_utime = decode_comp(av1.ac_utime) * 1000000;
104 av3->ac_stime = decode_comp(av1.ac_stime) * 1000000;
105 av3->ac_etime = decode_comp(av1.ac_etime) * 1000000;
106 av3->ac_btime = av1.ac_btime;
107 av3->ac_uid = av1.ac_uid;
108 av3->ac_gid = av1.ac_gid;
109 av3->ac_mem = av1.ac_mem;
110 av3->ac_io = decode_comp(av1.ac_io);
111 av3->ac_tty = av1.ac_tty;
112 av3->ac_flagx = av1.ac_flag | ANVER;
113 return (0);
114 }
115
116 /*
117 * Read an v2 accounting record stored at the current
118 * position of stream f.
119 * Return EOF on error or end-of-file.
120 */
121 static int
readrec_v2(FILE * f,struct acctv3 * av3)122 readrec_v2(FILE *f, struct acctv3 *av3)
123 {
124 struct acctv2 av2;
125 int rv;
126
127 if ((rv = fread_record(&av2, sizeof(av2), f)) == EOF)
128 return (EOF);
129 av3->ac_zero = 0;
130 av3->ac_version = 3;
131 av3->ac_len = av3->ac_len2 = sizeof(*av3);
132 memcpy(av3->ac_comm, av2.ac_comm, AC_COMM_LEN);
133 av3->ac_utime = av2.ac_utime;
134 av3->ac_stime = av2.ac_stime;
135 av3->ac_etime = av2.ac_etime;
136 av3->ac_btime = av2.ac_btime;
137 av3->ac_uid = av2.ac_uid;
138 av3->ac_gid = av2.ac_gid;
139 av3->ac_mem = av2.ac_mem;
140 av3->ac_io = av2.ac_io;
141 av3->ac_tty = av2.ac_tty;
142 av3->ac_flagx = av2.ac_flagx;
143 return (0);
144 }
145
146 /*
147 * Read an v2 accounting record stored at the current
148 * position of stream f.
149 * Return EOF on error or end-of-file.
150 */
151 static int
readrec_v3(FILE * f,struct acctv3 * av3)152 readrec_v3(FILE *f, struct acctv3 *av3)
153 {
154
155 return (fread_record(av3, sizeof(*av3), f));
156 }
157
158 /*
159 * Read a new-style (post-v1) accounting record stored at
160 * the current position of stream f.
161 * Convert the data to the current record format.
162 * Return EOF on error or end-of-file.
163 */
164 static int
readrec_vx(FILE * f,struct acctv3 * av3)165 readrec_vx(FILE *f, struct acctv3 *av3)
166 {
167 uint8_t magic, version;
168
169 if (fread_record(&magic, sizeof(magic), f) == EOF ||
170 fread_record(&version, sizeof(version), f) == EOF ||
171 ungetc(version, f) == EOF ||
172 ungetc(magic, f) == EOF)
173 return (EOF);
174 switch (version) {
175 case 2:
176 return (readrec_v2(f, av3));
177 case 3:
178 return (readrec_v3(f, av3));
179
180 /* Add handling for more versions here. */
181
182 default:
183 errno = EFTYPE;
184 return (EOF);
185 }
186 }
187
188 /*
189 * Read an accounting record stored at the current
190 * position of stream f.
191 * Old-format records are converted to the current record
192 * format.
193 * Return the number of records read (1 or 0 at the end-of-file),
194 * or EOF on error.
195 */
196 int
readrec_forward(FILE * f,struct acctv3 * av3)197 readrec_forward(FILE *f, struct acctv3 *av3)
198 {
199 int magic, rv;
200
201 if ((magic = getc(f)) == EOF)
202 return (ferror(f) ? EOF : 0);
203 if (ungetc(magic, f) == EOF)
204 return (EOF);
205 if (magic != 0)
206 /* Old record format. */
207 rv = readrec_v1(f, av3);
208 else
209 /* New record formats. */
210 rv = readrec_vx(f, av3);
211 return (rv == EOF ? EOF : 1);
212 }
213
214 /*
215 * Read an accounting record ending at the current
216 * position of stream f.
217 * Old-format records are converted to the current record
218 * format.
219 * The file pointer is positioned at the beginning of the
220 * record read.
221 * Return the number of records read (1 or 0 at the end-of-file),
222 * or EOF on error.
223 */
224 int
readrec_backward(FILE * f,struct acctv3 * av3)225 readrec_backward(FILE *f, struct acctv3 *av3)
226 {
227 off_t pos;
228 int c;
229 uint16_t len;
230
231 if ((pos = ftell(f)) == -1)
232 return (EOF);
233 if (pos == 0)
234 return (0);
235 if (fseek(f, -roffsetof(struct acctv3, ac_trailer),
236 SEEK_CUR) == EOF ||
237 (c = getc(f)) == EOF)
238 return (EOF);
239 if (c & ANVER) {
240 /*
241 * New record formats. For v2 and v3 offset from the
242 * end for ac_len2 should be same.
243 */
244 if (fseeko(f, pos - roffsetof(struct acctv2, ac_len2),
245 SEEK_SET) == EOF ||
246 fread_record(&len, sizeof(len), f) == EOF ||
247 fseeko(f, pos - len, SEEK_SET) == EOF ||
248 readrec_vx(f, av3) == EOF ||
249 fseeko(f, pos - len, SEEK_SET) == EOF)
250 return (EOF);
251 else
252 return (1);
253 } else {
254 /* Old record format. */
255 if (fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF ||
256 readrec_v1(f, av3) == EOF ||
257 fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF)
258 return (EOF);
259 else
260 return (1);
261 }
262 }
263