1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
32
33 #include <sys/param.h>
34 #include <sys/stat.h>
35 #include <sys/types.h>
36 #include <sys/acct.h>
37
38 #include <errno.h>
39 #include <stddef.h>
40 #include <stdio.h>
41 #include <string.h>
42
43 int readrec_forward(FILE *f, struct acctv3 *av2);
44 int readrec_backward(FILE *f, struct acctv3 *av2);
45
46 /*
47 * Reverse offsetof: return the offset of field f
48 * from the end of the structure s.
49 */
50 #define roffsetof(s, f) (sizeof(s) - offsetof(s, f))
51
52 /*
53 * Read exactly one record of size size from stream f into ptr.
54 * Failure to read the complete record is considered a file format error,
55 * and will set errno to EFTYPE.
56 * Return 0 on success, EOF on end of file or error.
57 */
58 static int
fread_record(void * ptr,size_t size,FILE * f)59 fread_record(void *ptr, size_t size, FILE *f)
60 {
61 size_t rv;
62
63 if ((rv = fread(ptr, 1, size, f)) == size)
64 return (0);
65 else if (ferror(f) || rv == 0)
66 return (EOF);
67 else {
68 /* Short read. */
69 errno = EFTYPE;
70 return (EOF);
71 }
72 }
73
74 /*
75 * Return the value of a comp_t field.
76 */
77 static float
decode_comp(comp_t v)78 decode_comp(comp_t v)
79 {
80 int result, exp;
81
82 result = v & 017777;
83 for (exp = v >> 13; exp; exp--)
84 result <<= 3;
85 return ((double)result / AHZV1);
86 }
87
88 /*
89 * Read a v1 accounting record stored at the current
90 * position of stream f.
91 * Convert the data to the current record format.
92 * Return EOF on error or end-of-file.
93 */
94 static int
readrec_v1(FILE * f,struct acctv3 * av3)95 readrec_v1(FILE *f, struct acctv3 *av3)
96 {
97 struct acctv1 av1;
98 int rv;
99
100 if ((rv = fread_record(&av1, sizeof(av1), f)) == EOF)
101 return (EOF);
102 av3->ac_zero = 0;
103 av3->ac_version = 3;
104 av3->ac_len = av3->ac_len2 = sizeof(*av3);
105 memcpy(av3->ac_comm, av1.ac_comm, AC_COMM_LEN);
106 av3->ac_utime = decode_comp(av1.ac_utime) * 1000000;
107 av3->ac_stime = decode_comp(av1.ac_stime) * 1000000;
108 av3->ac_etime = decode_comp(av1.ac_etime) * 1000000;
109 av3->ac_btime = av1.ac_btime;
110 av3->ac_uid = av1.ac_uid;
111 av3->ac_gid = av1.ac_gid;
112 av3->ac_mem = av1.ac_mem;
113 av3->ac_io = decode_comp(av1.ac_io);
114 av3->ac_tty = av1.ac_tty;
115 av3->ac_flagx = av1.ac_flag | ANVER;
116 return (0);
117 }
118
119 /*
120 * Read an v2 accounting record stored at the current
121 * position of stream f.
122 * Return EOF on error or end-of-file.
123 */
124 static int
readrec_v2(FILE * f,struct acctv3 * av3)125 readrec_v2(FILE *f, struct acctv3 *av3)
126 {
127 struct acctv2 av2;
128 int rv;
129
130 if ((rv = fread_record(&av2, sizeof(av2), f)) == EOF)
131 return (EOF);
132 av3->ac_zero = 0;
133 av3->ac_version = 3;
134 av3->ac_len = av3->ac_len2 = sizeof(*av3);
135 memcpy(av3->ac_comm, av2.ac_comm, AC_COMM_LEN);
136 av3->ac_utime = av2.ac_utime;
137 av3->ac_stime = av2.ac_stime;
138 av3->ac_etime = av2.ac_etime;
139 av3->ac_btime = av2.ac_btime;
140 av3->ac_uid = av2.ac_uid;
141 av3->ac_gid = av2.ac_gid;
142 av3->ac_mem = av2.ac_mem;
143 av3->ac_io = av2.ac_io;
144 av3->ac_tty = av2.ac_tty;
145 av3->ac_flagx = av2.ac_flagx;
146 return (0);
147 }
148
149 /*
150 * Read an v2 accounting record stored at the current
151 * position of stream f.
152 * Return EOF on error or end-of-file.
153 */
154 static int
readrec_v3(FILE * f,struct acctv3 * av3)155 readrec_v3(FILE *f, struct acctv3 *av3)
156 {
157
158 return (fread_record(av3, sizeof(*av3), f));
159 }
160
161 /*
162 * Read a new-style (post-v1) accounting record stored at
163 * the current position of stream f.
164 * Convert the data to the current record format.
165 * Return EOF on error or end-of-file.
166 */
167 static int
readrec_vx(FILE * f,struct acctv3 * av3)168 readrec_vx(FILE *f, struct acctv3 *av3)
169 {
170 uint8_t magic, version;
171
172 if (fread_record(&magic, sizeof(magic), f) == EOF ||
173 fread_record(&version, sizeof(version), f) == EOF ||
174 ungetc(version, f) == EOF ||
175 ungetc(magic, f) == EOF)
176 return (EOF);
177 switch (version) {
178 case 2:
179 return (readrec_v2(f, av3));
180 case 3:
181 return (readrec_v3(f, av3));
182
183 /* Add handling for more versions here. */
184
185 default:
186 errno = EFTYPE;
187 return (EOF);
188 }
189 }
190
191 /*
192 * Read an accounting record stored at the current
193 * position of stream f.
194 * Old-format records are converted to the current record
195 * format.
196 * Return the number of records read (1 or 0 at the end-of-file),
197 * or EOF on error.
198 */
199 int
readrec_forward(FILE * f,struct acctv3 * av3)200 readrec_forward(FILE *f, struct acctv3 *av3)
201 {
202 int magic, rv;
203
204 if ((magic = getc(f)) == EOF)
205 return (ferror(f) ? EOF : 0);
206 if (ungetc(magic, f) == EOF)
207 return (EOF);
208 if (magic != 0)
209 /* Old record format. */
210 rv = readrec_v1(f, av3);
211 else
212 /* New record formats. */
213 rv = readrec_vx(f, av3);
214 return (rv == EOF ? EOF : 1);
215 }
216
217 /*
218 * Read an accounting record ending at the current
219 * position of stream f.
220 * Old-format records are converted to the current record
221 * format.
222 * The file pointer is positioned at the beginning of the
223 * record read.
224 * Return the number of records read (1 or 0 at the end-of-file),
225 * or EOF on error.
226 */
227 int
readrec_backward(FILE * f,struct acctv3 * av3)228 readrec_backward(FILE *f, struct acctv3 *av3)
229 {
230 off_t pos;
231 int c;
232 uint16_t len;
233
234 if ((pos = ftell(f)) == -1)
235 return (EOF);
236 if (pos == 0)
237 return (0);
238 if (fseek(f, -roffsetof(struct acctv3, ac_trailer),
239 SEEK_CUR) == EOF ||
240 (c = getc(f)) == EOF)
241 return (EOF);
242 if (c & ANVER) {
243 /*
244 * New record formats. For v2 and v3 offset from the
245 * end for ac_len2 should be same.
246 */
247 if (fseeko(f, pos - roffsetof(struct acctv2, ac_len2),
248 SEEK_SET) == EOF ||
249 fread_record(&len, sizeof(len), f) == EOF ||
250 fseeko(f, pos - len, SEEK_SET) == EOF ||
251 readrec_vx(f, av3) == EOF ||
252 fseeko(f, pos - len, SEEK_SET) == EOF)
253 return (EOF);
254 else
255 return (1);
256 } else {
257 /* Old record format. */
258 if (fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF ||
259 readrec_v1(f, av3) == EOF ||
260 fseeko(f, pos - sizeof(struct acctv1), SEEK_SET) == EOF)
261 return (EOF);
262 else
263 return (1);
264 }
265 }
266