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      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
     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
     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
     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
    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
    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
    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
    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
    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
    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
    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