1 /*        $NetBSD: snprintb.c,v 1.49 2024/06/16 19:41:39 rillig Exp $ */
2 
3 /*-
4  * Copyright (c) 2002, 2024 The NetBSD Foundation, Inc.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef _STANDALONE
30 # ifndef _KERNEL
31 
32 #  if HAVE_NBTOOL_CONFIG_H
33 #   include "nbtool_config.h"
34 #  endif
35 
36 #  include <sys/cdefs.h>
37 #  if defined(LIBC_SCCS)
38 __RCSID("$NetBSD: snprintb.c,v 1.49 2024/06/16 19:41:39 rillig Exp $");
39 #  endif
40 
41 #  include <sys/types.h>
42 #  include <inttypes.h>
43 #  include <stdio.h>
44 #  include <string.h>
45 #  include <util.h>
46 #  include <errno.h>
47 # else /* ! _KERNEL */
48 #  include <sys/cdefs.h>
49 __KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.49 2024/06/16 19:41:39 rillig Exp $");
50 #  include <sys/param.h>
51 #  include <sys/inttypes.h>
52 #  include <sys/systm.h>
53 #  include <lib/libkern/libkern.h>
54 # endif /* ! _KERNEL */
55 
56 # ifndef HAVE_SNPRINTB_M
57 typedef struct {
58           char *const buf;
59           size_t const bufsize;
60           const char *bitfmt;
61           uint64_t const val;
62           size_t const line_max;
63 
64           char num_fmt[5];
65           size_t total_len;
66           size_t line_pos;
67           size_t comma_pos;
68           int in_angle_brackets;
69 } state;
70 
71 static void
store(state * s,char c)72 store(state *s, char c)
73 {
74           if (s->total_len < s->bufsize)
75                     s->buf[s->total_len] = c;
76           s->total_len++;
77 }
78 
79 static int
store_num(state * s,const char * fmt,uintmax_t num)80 store_num(state *s, const char *fmt, uintmax_t num)
81 {
82           int num_len = s->total_len < s->bufsize
83               ? snprintf(s->buf + s->total_len, s->bufsize - s->total_len,
84                     fmt, num)
85               : snprintf(NULL, 0, fmt, num);
86           if (num_len > 0)
87                     s->total_len += num_len;
88           return num_len;
89 }
90 
91 static void
store_eol(state * s)92 store_eol(state *s)
93 {
94           if (s->total_len - s->line_pos > s->line_max) {
95                     s->total_len = s->line_pos + s->line_max - 1;
96                     store(s, '#');
97           }
98           store(s, '\0');
99           s->line_pos = s->total_len;
100           s->comma_pos = 0;
101           s->in_angle_brackets = 0;
102 }
103 
104 static void
store_delimiter(state * s)105 store_delimiter(state *s)
106 {
107           if (s->in_angle_brackets) {
108                     s->comma_pos = s->total_len;
109                     store(s, ',');
110           } else {
111                     store(s, '<');
112                     s->in_angle_brackets = 1;
113           }
114 }
115 
116 static void
maybe_wrap_line(state * s,const char * bitfmt)117 maybe_wrap_line(state *s, const char *bitfmt)
118 {
119           if (s->line_max > 0
120               && s->comma_pos > 0
121               && s->total_len - s->line_pos >= s->line_max) {
122                     s->total_len = s->comma_pos;
123                     store(s, '>');
124                     store_eol(s);
125                     store_num(s, s->num_fmt, s->val);
126                     s->bitfmt = bitfmt;
127           }
128 }
129 
130 static int
old_style(state * s)131 old_style(state *s)
132 {
133           while (*s->bitfmt != '\0') {
134                     const char *cur_bitfmt = s->bitfmt;
135                     uint8_t bit = *s->bitfmt;
136                     if (bit > 32)
137                               return -1;
138                     if ((uint8_t)cur_bitfmt[1] <= 32)
139                               return -1;
140                     if (s->val & (1U << (bit - 1))) {
141                               store_delimiter(s);
142                               while ((uint8_t)*++s->bitfmt > 32)
143                                         store(s, *s->bitfmt);
144                               maybe_wrap_line(s, cur_bitfmt);
145                     } else
146                               while ((uint8_t)*++s->bitfmt > 32)
147                                         continue;
148           }
149           return 0;
150 }
151 
152 static int
new_style(state * s)153 new_style(state *s)
154 {
155           uint8_t field_kind = 0;       // 0 or 'f' or 'F'
156           uint64_t field = 0; // valid if field_kind != '\0'
157           int matched = 1;
158           const char *prev_bitfmt = s->bitfmt;
159           while (*s->bitfmt != '\0') {
160                     const char *cur_bitfmt = s->bitfmt;
161                     uint8_t kind = cur_bitfmt[0];
162                     switch (kind) {
163                     case 'b':
164                               field_kind = 0;
165                               prev_bitfmt = cur_bitfmt;
166                               uint8_t b_bit = cur_bitfmt[1];
167                               if (b_bit >= 64)
168                                         return -1;
169                               if (cur_bitfmt[2] == '\0')
170                                         return -1;
171                               s->bitfmt += 2;
172                               if (((s->val >> b_bit) & 1) == 0)
173                                         goto skip_description;
174                               store_delimiter(s);
175                               while (*s->bitfmt++ != '\0')
176                                         store(s, s->bitfmt[-1]);
177                               maybe_wrap_line(s, cur_bitfmt);
178                               break;
179                     case 'f':
180                     case 'F':
181                               field_kind = kind;
182                               prev_bitfmt = cur_bitfmt;
183                               matched = 0;
184                               uint8_t f_lsb = cur_bitfmt[1];
185                               if (f_lsb >= 64)
186                                         return -1;
187                               uint8_t f_width = cur_bitfmt[2];
188                               if (f_width > 64)
189                                         return -1;
190                               if (kind == 'f' && cur_bitfmt[3] == '\0')
191                                         return -1;
192                               field = s->val >> f_lsb;
193                               if (f_width < 64)
194                                         field &= ((uint64_t) 1 << f_width) - 1;
195                               s->bitfmt += 3;
196                               store_delimiter(s);
197                               if (kind == 'F')
198                                         goto skip_description;
199                               while (*s->bitfmt++ != '\0')
200                                         store(s, s->bitfmt[-1]);
201                               store(s, '=');
202                               store_num(s, s->num_fmt, field);
203                               maybe_wrap_line(s, cur_bitfmt);
204                               break;
205                     case '=':
206                     case ':':
207                               s->bitfmt += 2;
208                               if (kind == '=' && field_kind != 'f')
209                                         return -1;
210                               if (kind == ':' && field_kind != 'F')
211                                         return -1;
212                               uint8_t cmp = cur_bitfmt[1];
213                               if (cur_bitfmt[2] == '\0')
214                                         return -1;
215                               if (field != cmp)
216                                         goto skip_description;
217                               matched = 1;
218                               if (kind == '=')
219                                         store(s, '=');
220                               while (*s->bitfmt++ != '\0')
221                                         store(s, s->bitfmt[-1]);
222                               maybe_wrap_line(s, prev_bitfmt);
223                               break;
224                     case '*':
225                               if (field_kind == 0)
226                                         return -1;
227                               field_kind = 0;
228                               if (cur_bitfmt[1] == '\0')
229                                         return -1;
230                               s->bitfmt++;
231                               if (matched)
232                                         goto skip_description;
233                               matched = 1;
234                               if (store_num(s, s->bitfmt, field) < 0)
235                                         return -1;
236                               maybe_wrap_line(s, prev_bitfmt);
237                               goto skip_description;
238                     default:
239                               return -1;
240                     skip_description:
241                               while (*s->bitfmt++ != '\0')
242                                         continue;
243                               break;
244                     }
245           }
246           return 0;
247 }
248 
249 static void
finish_buffer(state * s)250 finish_buffer(state *s)
251 {
252           if (s->line_max > 0) {
253                     store_eol(s);
254                     store(s, '\0');
255                     if (s->total_len <= s->bufsize)
256                               return;
257                     if (s->bufsize >= 3)
258                               s->buf[s->bufsize - 3] = '#';
259                     if (s->bufsize >= 2)
260                               s->buf[s->bufsize - 2] = '\0';
261                     if (s->bufsize >= 1)
262                               s->buf[s->bufsize - 1] = '\0';
263           } else {
264                     store(s, '\0');
265                     if (s->total_len <= s->bufsize)
266                               return;
267                     if (s->bufsize >= 2)
268                               s->buf[s->bufsize - 2] = '#';
269                     if (s->bufsize >= 1)
270                               s->buf[s->bufsize - 1] = '\0';
271           }
272 }
273 
274 int
snprintb_m(char * buf,size_t bufsize,const char * bitfmt,uint64_t val,size_t line_max)275 snprintb_m(char *buf, size_t bufsize, const char *bitfmt, uint64_t val,
276              size_t line_max)
277 {
278           int old = *bitfmt != '\177';
279           if (!old)
280                     bitfmt++;
281 
282           state s = {
283                     .buf = buf,
284                     .bufsize = bufsize,
285                     .bitfmt = bitfmt,
286                     .val = val,
287                     .line_max = line_max,
288           };
289           int had_error = 0;
290 
291           switch (*s.bitfmt++) {
292           case 8:
293                     memcpy(s.num_fmt, "%#jo", 4);
294                     break;
295           case 10:
296                     memcpy(s.num_fmt, "%ju", 4);
297                     break;
298           case 16:
299                     memcpy(s.num_fmt, "%#jx", 4);
300                     break;
301           default:
302                     goto had_error;
303           }
304 
305           store_num(&s, s.num_fmt, val);
306 
307           if ((old ? old_style(&s) : new_style(&s)) < 0) {
308 had_error:
309 #ifndef _KERNEL
310                     errno = EINVAL;
311 #endif
312                     had_error = 1;
313                     store(&s, '#');
314           } else if (s.in_angle_brackets)
315                     store(&s, '>');
316           finish_buffer(&s);
317           return had_error ? -1 : (int)(s.total_len - 1);
318 }
319 
320 int
snprintb(char * buf,size_t bufsize,const char * bitfmt,uint64_t val)321 snprintb(char *buf, size_t bufsize, const char *bitfmt, uint64_t val)
322 {
323           return snprintb_m(buf, bufsize, bitfmt, val, 0);
324 }
325 # endif /* ! HAVE_SNPRINTB_M */
326 #endif /* ! _STANDALONE */
327