xref: /lighttpd1.4/src/buffer.c (revision 4f0261e5)
1 #include "first.h"
2 
3 #include "buffer.h"
4 #include "settings.h"   /* BUFFER_MAX_REUSE_SIZE */
5 
6 #include <stdlib.h>
7 #include <string.h>
8 #include <time.h>       /* strftime() */
9 
10 static const char hex_chars_lc[] = "0123456789abcdef";
11 static const char hex_chars_uc[] = "0123456789ABCDEF";
12 
13 /**
14  * init the buffer
15  *
16  */
17 
18 buffer* buffer_init(void) {
19 	buffer *b;
20 
21 	b = malloc(sizeof(*b));
22 	force_assert(b);
23 
24 	b->ptr = NULL;
25 	b->size = 0;
26 	b->used = 0;
27 
28 	return b;
29 }
30 
31 buffer *buffer_init_buffer(const buffer *src) {
32 	buffer *b = buffer_init();
33 	buffer_copy_buffer(b, src);
34 	return b;
35 }
36 
37 buffer *buffer_init_string(const char *str) {
38 	buffer *b = buffer_init();
39 	buffer_copy_string(b, str);
40 	return b;
41 }
42 
43 void buffer_free(buffer *b) {
44 	if (NULL == b) return;
45 
46 	free(b->ptr);
47 	free(b);
48 }
49 
50 __attribute_cold__
51 static void buffer_free_ptr(buffer *b) {
52 	if (NULL == b) return;
53 	free(b->ptr);
54 	b->ptr = NULL;
55 	b->used = 0;
56 	b->size = 0;
57 }
58 
59 void buffer_reset(buffer *b) {
60 	if (NULL != b && b->size > 0) {
61 		b->used = 0;
62 		/* release buffer larger than ... bytes */
63 		if (b->size > BUFFER_MAX_REUSE_SIZE) buffer_free_ptr(b);
64 	}
65 }
66 
67 void buffer_move(buffer *b, buffer *src) {
68 	buffer tmp;
69 	force_assert(NULL != b);
70 	force_assert(NULL != src);
71 
72 	buffer_clear(b);
73 	tmp = *src; *src = *b; *b = tmp;
74 }
75 
76 /* make sure buffer is at least "size" big + 1 for '\0'. keep old data */
77 __attribute_cold__
78 static void buffer_realloc(buffer *b, size_t len) {
79     #define BUFFER_PIECE_SIZE 64uL  /*(must be power-of-2)*/
80     const size_t sz = (len + 1 + BUFFER_PIECE_SIZE-1) & ~(BUFFER_PIECE_SIZE-1);
81     force_assert(sz > len);
82 
83     b->size = sz;
84     b->ptr = realloc(b->ptr, sz);
85 
86     force_assert(NULL != b->ptr);
87 }
88 
89 __attribute_cold__
90 static void buffer_alloc_replace(buffer *b, size_t size) {
91     /*(discard old data so realloc() does not copy)*/
92     if (NULL != b->ptr) {
93         free(b->ptr);
94         b->ptr = NULL;
95     }
96     buffer_realloc(b, size);
97 }
98 
99 char* buffer_string_prepare_copy(buffer *b, size_t size) {
100 	force_assert(NULL != b);
101 
102 	if (size >= b->size) buffer_alloc_replace(b, size);
103 
104 	b->used = 0;
105 	return b->ptr;
106 }
107 
108 char* buffer_string_prepare_append(buffer *b, size_t size) {
109 	force_assert(NULL !=  b);
110 
111 	if (b->used && size < b->size - b->used)
112 		return b->ptr + b->used - 1;
113 
114 	if (buffer_string_is_empty(b)) {
115 		return buffer_string_prepare_copy(b, size);
116 	} else {
117 		/* not empty, b->used already includes a terminating 0 */
118 		size_t req_size = b->used + size;
119 
120 		/* check for overflow: unsigned overflow is defined to wrap around */
121 		force_assert(req_size >= b->used);
122 
123 		buffer_realloc(b, req_size);
124 
125 		return b->ptr + b->used - 1;
126 	}
127 }
128 
129 void buffer_string_set_length(buffer *b, size_t len) {
130 	force_assert(NULL != b);
131 
132 	if (len >= b->size) buffer_realloc(b, len);
133 
134 	b->used = len + 1;
135 	b->ptr[len] = '\0';
136 }
137 
138 void buffer_commit(buffer *b, size_t size)
139 {
140 	force_assert(NULL != b);
141 	force_assert(b->size > 0);
142 
143 	if (0 == b->used) b->used = 1;
144 
145 	if (size > 0) {
146 		/* check for overflow: unsigned overflow is defined to wrap around */
147 		size_t sz = b->used + size;
148 		force_assert(sz > b->used);
149 		force_assert(sz <= b->size);
150 		b->used = sz;
151 	}
152 
153 	b->ptr[b->used - 1] = '\0';
154 }
155 
156 void buffer_copy_string(buffer *b, const char *s) {
157 	buffer_copy_string_len(b, s, NULL != s ? strlen(s) : 0);
158 }
159 
160 void buffer_copy_string_len(buffer *b, const char *s, size_t s_len) {
161 	force_assert(NULL != b);
162 	force_assert(NULL != s || s_len == 0);
163 
164 	if (s_len >= b->size) buffer_string_prepare_copy(b, s_len);
165 
166 	if (0 != s_len) memcpy(b->ptr, s, s_len); /*(s might be NULL)*/
167 	b->ptr[s_len] = '\0';
168 	b->used = s_len + 1;
169 }
170 
171 void buffer_append_string(buffer *b, const char *s) {
172 	buffer_append_string_len(b, s, NULL != s ? strlen(s) : 0);
173 }
174 
175 /**
176  * append a string to the end of the buffer
177  *
178  * the resulting buffer is terminated with a '\0'
179  * s is treated as a un-terminated string (a \0 is handled a normal character)
180  *
181  * @param b a buffer
182  * @param s the string
183  * @param s_len size of the string (without the terminating \0)
184  */
185 
186 void buffer_append_string_len(buffer *b, const char *s, size_t s_len) {
187 	char *target_buf;
188 
189 	force_assert(NULL != b);
190 	force_assert(NULL != s || s_len == 0);
191 
192 	target_buf = buffer_string_prepare_append(b, s_len);
193 	if (0 == b->used) ++b->used; /*(must include '\0' for append below)*/
194 
195 	/*(s might be NULL if 0 == s_len)*/
196 	if (s_len) memcpy(target_buf, s, s_len);
197 	target_buf[s_len] = '\0';
198 	b->used += s_len;
199 }
200 
201 void buffer_append_path_len(buffer *b, const char *a, size_t alen) {
202     size_t blen = buffer_string_length(b);
203     int aslash = (alen && a[0] == '/');
204     buffer_string_prepare_append(b, alen+2); /*(+ '/' and + '\0' if 0 == blen)*/
205     if (blen && b->ptr[blen-1] == '/') {
206         if (aslash) --b->used;
207     }
208     else {
209         if (!b->used) ++b->used;
210         if (!aslash) b->ptr[++b->used - 2] = '/';
211     }
212     memcpy(b->ptr+b->used-1, a, alen);
213     b->ptr[(b->used += alen)-1] = '\0';
214 }
215 
216 void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
217 	char *buf;
218 	unsigned int shift = 0;
219 
220 	{
221 		uintmax_t copy = value;
222 		do {
223 			copy >>= 8;
224 			shift += 8; /* counting bits */
225 		} while (0 != copy);
226 	}
227 
228 	buf = buffer_string_prepare_append(b, shift >> 2); /*nibbles (4 bits)*/
229 	buffer_commit(b, shift >> 2); /* will fill below */
230 
231 	while (shift > 0) {
232 		shift -= 4;
233 		*(buf++) = hex_chars_lc[(value >> shift) & 0x0F];
234 	}
235 }
236 
237 static char* utostr(char * const buf_end, uintmax_t val) {
238 	char *cur = buf_end;
239 	do {
240 		int mod = val % 10;
241 		val /= 10;
242 		/* prepend digit mod */
243 		*(--cur) = (char) ('0' + mod);
244 	} while (0 != val);
245 	return cur;
246 }
247 
248 static char* itostr(char * const buf_end, intmax_t val) {
249 	/* absolute value not defined for INTMAX_MIN, but can take absolute
250 	 * value of any negative number via twos complement cast to unsigned.
251 	 * negative sign is prepended after (now unsigned) value is converted
252 	 * to string */
253 	uintmax_t uval = val >= 0 ? (uintmax_t)val : ((uintmax_t)~val) + 1;
254 	char *cur = utostr(buf_end, uval);
255 	if (val < 0) *(--cur) = '-';
256 
257 	return cur;
258 }
259 
260 void buffer_append_int(buffer *b, intmax_t val) {
261 	char buf[LI_ITOSTRING_LENGTH];
262 	char* const buf_end = buf + sizeof(buf);
263 	char *str;
264 
265 	force_assert(NULL != b);
266 
267 	str = itostr(buf_end, val);
268 	force_assert(buf_end > str && str >= buf);
269 
270 	buffer_append_string_len(b, str, buf_end - str);
271 }
272 
273 void buffer_copy_int(buffer *b, intmax_t val) {
274 	force_assert(NULL != b);
275 
276 	b->used = 0;
277 	buffer_append_int(b, val);
278 }
279 
280 void buffer_append_strftime(buffer *b, const char *format, const struct tm *tm) {
281 	size_t r;
282 	char* buf;
283 	force_assert(NULL != b);
284 	force_assert(NULL != format);
285 	force_assert(NULL != tm);
286 
287 	buf = buffer_string_prepare_append(b, 255);
288 	r = strftime(buf, buffer_string_space(b), format, tm);
289 
290 	/* 0 (in some apis buffer_string_space(b)) signals the string may have
291 	 * been too small; but the format could also just have lead to an empty
292 	 * string
293 	 */
294 	if (0 == r || r >= buffer_string_space(b)) {
295 		/* give it a second try with a larger string */
296 		buf = buffer_string_prepare_append(b, 4095);
297 		r = strftime(buf, buffer_string_space(b), format, tm);
298 	}
299 
300 	if (r >= buffer_string_space(b)) r = 0;
301 
302 	buffer_commit(b, r);
303 }
304 
305 
306 void li_itostrn(char *buf, size_t buf_len, intmax_t val) {
307 	char p_buf[LI_ITOSTRING_LENGTH];
308 	char* const p_buf_end = p_buf + sizeof(p_buf);
309 	char* str = p_buf_end - 1;
310 	*str = '\0';
311 
312 	str = itostr(str, val);
313 	force_assert(p_buf_end > str && str >= p_buf);
314 
315 	force_assert(buf_len >= (size_t) (p_buf_end - str));
316 	memcpy(buf, str, p_buf_end - str);
317 }
318 
319 void li_utostrn(char *buf, size_t buf_len, uintmax_t val) {
320 	char p_buf[LI_ITOSTRING_LENGTH];
321 	char* const p_buf_end = p_buf + sizeof(p_buf);
322 	char* str = p_buf_end - 1;
323 	*str = '\0';
324 
325 	str = utostr(str, val);
326 	force_assert(p_buf_end > str && str >= p_buf);
327 
328 	force_assert(buf_len >= (size_t) (p_buf_end - str));
329 	memcpy(buf, str, p_buf_end - str);
330 }
331 
332 #define li_ntox_lc(n) ((n) <= 9 ? (n) + '0' : (n) + 'a' - 10)
333 
334 char int2hex(char c) {
335 	/*return li_ntox_lc(c & 0xF);*/
336 	return hex_chars_lc[(c & 0x0F)];
337 }
338 
339 /* c (char) and n (nibble) MUST be unsigned integer types */
340 #define li_cton(c,n) \
341   (((n) = (c) - '0') <= 9 || (((n) = ((c)&0xdf) - 'A') <= 5 ? ((n) += 10) : 0))
342 
343 /* converts hex char (0-9, A-Z, a-z) to decimal.
344  * returns 0xFF on invalid input.
345  */
346 char hex2int(unsigned char hex) {
347 	unsigned char n;
348 	return li_cton(hex,n) ? (char)n : 0xFF;
349 }
350 
351 /**
352  * check if two buffer contain the same data
353  */
354 
355 int buffer_is_equal(const buffer *a, const buffer *b) {
356 	force_assert(NULL != a && NULL != b);
357 
358 	/* 1 = equal; 0 = not equal */
359 	return (a->used == b->used && 0 == memcmp(a->ptr, b->ptr, a->used));
360 }
361 
362 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len) {
363 	force_assert(NULL != a && NULL != s);
364 	force_assert(b_len + 1 > b_len);
365 
366 	/* 1 = equal; 0 = not equal */
367 	return (a->used == b_len + 1 && 0 == memcmp(a->ptr, s, b_len));
368 }
369 
370 /* buffer_is_equal_caseless_string(b, CONST_STR_LEN("value")) */
371 int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len) {
372 	force_assert(NULL != a && NULL != s);
373 	force_assert(b_len + 1 > b_len);
374 
375 	/* 1 = equal; 0 = not equal */
376 	return (a->used == b_len + 1 && 0 == strncasecmp(a->ptr, s, b_len));
377 }
378 
379 int buffer_caseless_compare(const char *a, size_t a_len, const char *b, size_t b_len) {
380 	size_t const len = (a_len < b_len) ? a_len : b_len;
381 	size_t i;
382 
383 	for (i = 0; i < len; ++i) {
384 		unsigned char ca = a[i], cb = b[i];
385 		if (ca == cb) continue;
386 
387 		/* always lowercase for transitive results */
388 		if (ca >= 'A' && ca <= 'Z') ca |= 32;
389 		if (cb >= 'A' && cb <= 'Z') cb |= 32;
390 
391 		if (ca == cb) continue;
392 		return ((int)ca) - ((int)cb);
393 	}
394 	if (a_len == b_len) return 0;
395 	return a_len < b_len ? -1 : 1;
396 }
397 
398 int buffer_is_equal_right_len(const buffer *b1, const buffer *b2, size_t len) {
399 	/* no len -> equal */
400 	if (len == 0) return 1;
401 
402 	/* len > 0, but empty buffers -> not equal */
403 	if (b1->used == 0 || b2->used == 0) return 0;
404 
405 	/* buffers too small -> not equal */
406 	if (b1->used - 1 < len || b2->used - 1 < len) return 0;
407 
408 	return 0 == memcmp(b1->ptr + b1->used - 1 - len, b2->ptr + b2->used - 1 - len, len);
409 }
410 
411 
412 void li_tohex_lc(char *buf, size_t buf_len, const char *s, size_t s_len) {
413 	force_assert(2 * s_len > s_len);
414 	force_assert(2 * s_len < buf_len);
415 
416 	for (size_t i = 0; i < s_len; ++i) {
417 		buf[2*i]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
418 		buf[2*i+1] = hex_chars_lc[s[i] & 0x0F];
419 	}
420 	buf[2*s_len] = '\0';
421 }
422 
423 void li_tohex_uc(char *buf, size_t buf_len, const char *s, size_t s_len) {
424 	force_assert(2 * s_len > s_len);
425 	force_assert(2 * s_len < buf_len);
426 
427 	for (size_t i = 0; i < s_len; ++i) {
428 		buf[2*i]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
429 		buf[2*i+1] = hex_chars_uc[s[i] & 0x0F];
430 	}
431 	buf[2*s_len] = '\0';
432 }
433 
434 
435 void buffer_substr_replace (buffer * const b, const size_t offset,
436                             const size_t len, const buffer * const replace)
437 {
438     const size_t blen = buffer_string_length(b);
439     const size_t rlen = buffer_string_length(replace);
440 
441     if (rlen > len) {
442         buffer_string_set_length(b, blen-len+rlen);
443         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
444     }
445 
446     memcpy(b->ptr+offset, replace->ptr, rlen);
447 
448     if (rlen < len) {
449         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
450         buffer_string_set_length(b, blen-len+rlen);
451     }
452 }
453 
454 
455 void buffer_append_string_encoded_hex_lc(buffer *b, const char *s, size_t len) {
456     unsigned char * const p =
457       (unsigned char*) buffer_string_prepare_append(b, len*2);
458     buffer_commit(b, len*2); /* fill below */
459     for (size_t i = 0; i < len; ++i) {
460         p[(i<<1)]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
461         p[(i<<1)+1] = hex_chars_lc[(s[i])      & 0x0F];
462     }
463 }
464 
465 void buffer_append_string_encoded_hex_uc(buffer *b, const char *s, size_t len) {
466     unsigned char * const p =
467       (unsigned char*) buffer_string_prepare_append(b, len*2);
468     buffer_commit(b, len*2); /* fill below */
469     for (size_t i = 0; i < len; ++i) {
470         p[(i<<1)]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
471         p[(i<<1)+1] = hex_chars_uc[(s[i])      & 0x0F];
472     }
473 }
474 
475 
476 /* everything except: ! ( ) * - . 0-9 A-Z _ a-z */
477 static const char encoded_chars_rel_uri_part[] = {
478 	/*
479 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
480 	*/
481 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
482 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
483 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1,  /*  20 -  2F space " # $ % & ' + , / */
484 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
485 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
486 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
487 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
488 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
489 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
490 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
491 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
492 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
493 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
494 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
495 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
496 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
497 };
498 
499 /* everything except: ! ( ) * - . / 0-9 A-Z _ a-z */
500 static const char encoded_chars_rel_uri[] = {
501 	/*
502 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
503 	*/
504 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
505 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
506 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0,  /*  20 -  2F space " # $ % & ' + , */
507 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
508 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
509 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
510 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
511 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
512 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
513 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
514 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
515 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
516 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
517 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
518 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
519 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
520 };
521 
522 static const char encoded_chars_html[] = {
523 	/*
524 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
525 	*/
526 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
527 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
528 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
529 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
530 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
531 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
532 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
533 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
534 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
535 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
536 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
537 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
538 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
539 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
540 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
541 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
542 };
543 
544 static const char encoded_chars_minimal_xml[] = {
545 	/*
546 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
547 	*/
548 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
549 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
550 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
551 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
552 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
553 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
554 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
555 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
556 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  80 -  8F */
557 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  90 -  9F */
558 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  A0 -  AF */
559 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  B0 -  BF */
560 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  C0 -  CF */
561 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  D0 -  DF */
562 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  E0 -  EF */
563 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  F0 -  FF */
564 };
565 
566 
567 
568 void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer_encoding_t encoding) {
569 	unsigned char *ds, *d;
570 	size_t d_len, ndx;
571 	const char *map = NULL;
572 
573 	force_assert(NULL != b);
574 	force_assert(NULL != s || 0 == s_len);
575 
576 	if (0 == s_len) return;
577 
578 	switch(encoding) {
579 	case ENCODING_REL_URI:
580 		map = encoded_chars_rel_uri;
581 		break;
582 	case ENCODING_REL_URI_PART:
583 		map = encoded_chars_rel_uri_part;
584 		break;
585 	case ENCODING_HTML:
586 		map = encoded_chars_html;
587 		break;
588 	case ENCODING_MINIMAL_XML:
589 		map = encoded_chars_minimal_xml;
590 		break;
591 	}
592 
593 	force_assert(NULL != map);
594 
595 	/* count to-be-encoded-characters */
596 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
597 		if (map[*ds]) {
598 			switch(encoding) {
599 			case ENCODING_REL_URI:
600 			case ENCODING_REL_URI_PART:
601 				d_len += 3;
602 				break;
603 			case ENCODING_HTML:
604 			case ENCODING_MINIMAL_XML:
605 				d_len += 6;
606 				break;
607 			}
608 		} else {
609 			d_len++;
610 		}
611 	}
612 
613 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
614 	buffer_commit(b, d_len); /* fill below */
615 
616 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
617 		if (map[*ds]) {
618 			switch(encoding) {
619 			case ENCODING_REL_URI:
620 			case ENCODING_REL_URI_PART:
621 				d[d_len++] = '%';
622 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
623 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
624 				break;
625 			case ENCODING_HTML:
626 			case ENCODING_MINIMAL_XML:
627 				d[d_len++] = '&';
628 				d[d_len++] = '#';
629 				d[d_len++] = 'x';
630 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
631 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
632 				d[d_len++] = ';';
633 				break;
634 			}
635 		} else {
636 			d[d_len++] = *ds;
637 		}
638 	}
639 }
640 
641 void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len) {
642 	unsigned char *ds, *d;
643 	size_t d_len, ndx;
644 
645 	force_assert(NULL != b);
646 	force_assert(NULL != s || 0 == s_len);
647 
648 	if (0 == s_len) return;
649 
650 	/* count to-be-encoded-characters */
651 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
652 		if ((*ds < 0x20) /* control character */
653 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
654 			switch (*ds) {
655 			case '\t':
656 			case '\r':
657 			case '\n':
658 				d_len += 2;
659 				break;
660 			default:
661 				d_len += 4; /* \xCC */
662 				break;
663 			}
664 		} else {
665 			d_len++;
666 		}
667 	}
668 
669 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
670 	buffer_commit(b, d_len); /* fill below */
671 
672 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
673 		if ((*ds < 0x20) /* control character */
674 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
675 			d[d_len++] = '\\';
676 			switch (*ds) {
677 			case '\t':
678 				d[d_len++] = 't';
679 				break;
680 			case '\r':
681 				d[d_len++] = 'r';
682 				break;
683 			case '\n':
684 				d[d_len++] = 'n';
685 				break;
686 			default:
687 				d[d_len++] = 'x';
688 				d[d_len++] = hex_chars_lc[((*ds) >> 4) & 0x0F];
689 				d[d_len++] = hex_chars_lc[(*ds) & 0x0F];
690 				break;
691 			}
692 		} else {
693 			d[d_len++] = *ds;
694 		}
695 	}
696 }
697 
698 
699 void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header) {
700 	size_t i, j = 0;
701 
702 	force_assert(NULL != b);
703 	force_assert(NULL != s || 0 == s_len);
704 
705 	buffer_string_prepare_copy(b, s_len + 5);
706 
707 	if (is_http_header && NULL != s && 0 != strcasecmp(s, "CONTENT-TYPE")) {
708 		buffer_copy_string_len(b, CONST_STR_LEN("HTTP_"));
709 		j = 5; /* "HTTP_" */
710 	}
711 
712 	for (i = 0; i < s_len; ++i) {
713 		unsigned char cr = s[i];
714 		if (light_isalpha(cr)) {
715 			/* upper-case */
716 			cr &= ~32;
717 		} else if (!light_isdigit(cr)) {
718 			cr = '_';
719 		}
720 		b->ptr[j++] = cr;
721 	}
722 	b->used = j;
723 	b->ptr[b->used++] = '\0';
724 }
725 
726 /* decodes url-special-chars inplace.
727  * replaces non-printable characters with '_'
728  */
729 
730 static void buffer_urldecode_internal(buffer *url, int is_query) {
731 	unsigned char high, low;
732 	char *src;
733 	char *dst;
734 
735 	force_assert(NULL != url);
736 	if (buffer_string_is_empty(url)) return;
737 
738 	force_assert('\0' == url->ptr[url->used-1]);
739 
740 	src = (char*) url->ptr;
741 
742 	while ('\0' != *src) {
743 		if ('%' == *src) break;
744 		if (is_query && '+' == *src) *src = ' ';
745 		src++;
746 	}
747 	dst = src;
748 
749 	while ('\0' != *src) {
750 		if (is_query && *src == '+') {
751 			*dst = ' ';
752 		} else if (*src == '%') {
753 			*dst = '%';
754 
755 			high = hex2int(*(src + 1));
756 			if (0xFF != high) {
757 				low = hex2int(*(src + 2));
758 				if (0xFF != low) {
759 					high = (high << 4) | low;
760 
761 					/* map control-characters out */
762 					if (high < 32 || high == 127) high = '_';
763 
764 					*dst = high;
765 					src += 2;
766 				}
767 			}
768 		} else {
769 			*dst = *src;
770 		}
771 
772 		dst++;
773 		src++;
774 	}
775 
776 	*dst = '\0';
777 	url->used = (dst - url->ptr) + 1;
778 }
779 
780 void buffer_urldecode_path(buffer *url) {
781 	buffer_urldecode_internal(url, 0);
782 }
783 
784 void buffer_urldecode_query(buffer *url) {
785 	buffer_urldecode_internal(url, 1);
786 }
787 
788 int buffer_is_valid_UTF8(const buffer *b) {
789     /* https://www.w3.org/International/questions/qa-forms-utf-8 */
790     const unsigned char *c = (unsigned char *)b->ptr;
791     while (*c) {
792 
793         /*(note: includes ctrls)*/
794         if (                         c[0] <  0x80 ) { ++c;  continue; }
795 
796         if (         0xc2 <= c[0] && c[0] <= 0xdf
797             &&       0x80 <= c[1] && c[1] <= 0xbf ) { c+=2; continue; }
798 
799         if ( (   (   0xe0 == c[0]
800                   && 0xa0 <= c[1] && c[1] <= 0xbf)
801               || (   0xe1 <= c[0] && c[0] <= 0xef && c[0] != 0xed
802                   && 0x80 <= c[1] && c[1] <= 0xbf)
803               || (   0xed == c[0]
804                   && 0x80 <= c[1] && c[1] <= 0x9f)   )
805             &&       0x80 <= c[2] && c[2] <= 0xbf ) { c+=3; continue; }
806 
807         if ( (   (   0xf0 == c[0]
808                   && 0x90 <= c[1] && c[1] <= 0xbf)
809               || (   0xf1 <= c[0] && c[0] <= 0xf3
810                   && 0x80 <= c[1] && c[1] <= 0xbf)
811               || (   0xf4 == c[0]
812                   && 0x80 <= c[1] && c[1] <= 0x8f)   )
813             &&       0x80 <= c[2] && c[2] <= 0xbf
814             &&       0x80 <= c[3] && c[3] <= 0xbf ) { c+=4; continue; }
815 
816         return 0; /* invalid */
817     }
818     return 1; /* valid */
819 }
820 
821 /* - special case: empty string returns empty string
822  * - on windows or cygwin: replace \ with /
823  * - strip leading spaces
824  * - prepends "/" if not present already
825  * - resolve "/../", "//" and "/./" the usual way:
826  *   the first one removes a preceding component, the other two
827  *   get compressed to "/".
828  * - "/." and "/.." at the end are similar, but always leave a trailing
829  *   "/"
830  *
831  * /blah/..         gets  /
832  * /blah/../foo     gets  /foo
833  * /abc/./xyz       gets  /abc/xyz
834  * /abc//xyz        gets  /abc/xyz
835  *
836  * NOTE: src and dest can point to the same buffer, in which case,
837  *       the operation is performed in-place.
838  */
839 
840 void buffer_path_simplify(buffer *dest, buffer *src)
841 {
842 	/* current character, the one before, and the one before that from input */
843 	char c, pre1, pre2;
844 	char *start, *slash, *walk, *out;
845 
846 	force_assert(NULL != dest && NULL != src);
847 
848 	if (buffer_string_is_empty(src)) {
849 		buffer_copy_string_len(dest, CONST_STR_LEN(""));
850 		return;
851 	}
852 
853 	force_assert('\0' == src->ptr[src->used-1]);
854 
855 #if defined(__WIN32) || defined(__CYGWIN__)
856 	/* cygwin is treating \ and / the same, so we have to that too */
857 	{
858 		char *p;
859 		for (p = src->ptr; *p; p++) {
860 			if (*p == '\\') *p = '/';
861 		}
862 	}
863 #endif
864 
865 	walk  = src->ptr;
866 	start = dest->ptr;
867 	out   = dest->ptr;
868 	slash = dest->ptr;
869 
870 	/* skip leading spaces */
871 	while (*walk == ' ') {
872 		walk++;
873 	}
874 	if (*walk == '.') {
875 		if (walk[1] == '/' || walk[1] == '\0')
876 			++walk;
877 		else if (walk[1] == '.' && (walk[2] == '/' || walk[2] == '\0'))
878 			walk+=2;
879 	}
880 
881 	pre1 = 0;
882 	c = *(walk++);
883 
884 	while (c != '\0') {
885 		/* assert((src != dest || out <= walk) && slash <= out); */
886 		/* the following comments about out and walk are only interesting if
887 		 * src == dest; otherwise the memory areas don't overlap anyway.
888 		 */
889 		pre2 = pre1;
890 		pre1 = c;
891 
892 		/* possibly: out == walk - need to read first */
893 		c    = *walk;
894 		*out = pre1;
895 
896 		out++;
897 		walk++;
898 		/* (out <= walk) still true; also now (slash < out) */
899 
900 		if (c == '/' || c == '\0') {
901 			const size_t toklen = out - slash;
902 			if (toklen == 3 && pre2 == '.' && pre1 == '.' && *slash == '/') {
903 				/* "/../" or ("/.." at end of string) */
904 				out = slash;
905 				/* if there is something before "/..", there is at least one
906 				 * component, which needs to be removed */
907 				if (out > start) {
908 					out--;
909 					while (out > start && *out != '/') out--;
910 				}
911 
912 				/* don't kill trailing '/' at end of path */
913 				if (c == '\0') out++;
914 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
915 			} else if (toklen == 1 || (pre2 == '/' && pre1 == '.')) {
916 				/* "//" or "/./" or (("/" or "/.") at end of string) */
917 				out = slash;
918 				/* don't kill trailing '/' at end of path */
919 				if (c == '\0') out++;
920 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
921 			}
922 
923 			slash = out;
924 		}
925 	}
926 
927 	buffer_string_set_length(dest, out - start);
928 }
929 
930 void buffer_to_lower(buffer *b) {
931 	size_t i;
932 
933 	for (i = 0; i < b->used; ++i) {
934 		char c = b->ptr[i];
935 		if (c >= 'A' && c <= 'Z') b->ptr[i] |= 0x20;
936 	}
937 }
938 
939 
940 void buffer_to_upper(buffer *b) {
941 	size_t i;
942 
943 	for (i = 0; i < b->used; ++i) {
944 		char c = b->ptr[i];
945 		if (c >= 'a' && c <= 'z') b->ptr[i] &= ~0x20;
946 	}
947 }
948 
949 
950 #include <stdio.h>
951 
952 #ifdef HAVE_LIBUNWIND
953 # define UNW_LOCAL_ONLY
954 # include <libunwind.h>
955 
956 static void print_backtrace(FILE *file) {
957 	unw_cursor_t cursor;
958 	unw_context_t context;
959 	int ret;
960 	unsigned int frame = 0;
961 
962 	if (0 != (ret = unw_getcontext(&context))) goto error;
963 	if (0 != (ret = unw_init_local(&cursor, &context))) goto error;
964 
965 	fprintf(file, "Backtrace:\n");
966 
967 	while (0 < (ret = unw_step(&cursor))) {
968 		unw_word_t proc_ip = 0;
969 		unw_proc_info_t procinfo;
970 		char procname[256];
971 		unw_word_t proc_offset = 0;
972 
973 		if (0 != (ret = unw_get_reg(&cursor, UNW_REG_IP, &proc_ip))) goto error;
974 
975 		if (0 == proc_ip) {
976 			/* without an IP the other functions are useless; unw_get_proc_name would return UNW_EUNSPEC */
977 			++frame;
978 			fprintf(file, "%u: (nil)\n", frame);
979 			continue;
980 		}
981 
982 		if (0 != (ret = unw_get_proc_info(&cursor, &procinfo))) goto error;
983 
984 		if (0 != (ret = unw_get_proc_name(&cursor, procname, sizeof(procname), &proc_offset))) {
985 			switch (-ret) {
986 			case UNW_ENOMEM:
987 				memset(procname + sizeof(procname) - 4, '.', 3);
988 				procname[sizeof(procname) - 1] = '\0';
989 				break;
990 			case UNW_ENOINFO:
991 				procname[0] = '?';
992 				procname[1] = '\0';
993 				proc_offset = 0;
994 				break;
995 			default:
996 				snprintf(procname, sizeof(procname), "?? (unw_get_proc_name error %d)", -ret);
997 				break;
998 			}
999 		}
1000 
1001 		++frame;
1002 		fprintf(file, "%u: %s (+0x%x) [%p]\n",
1003 			frame,
1004 			procname,
1005 			(unsigned int) proc_offset,
1006 			(void*)(uintptr_t)proc_ip);
1007 	}
1008 
1009 	if (0 != ret) goto error;
1010 
1011 	return;
1012 
1013 error:
1014 	fprintf(file, "Error while generating backtrace: unwind error %i\n", (int) -ret);
1015 }
1016 #else
1017 static void print_backtrace(FILE *file) {
1018 	UNUSED(file);
1019 }
1020 #endif
1021 
1022 void log_failed_assert(const char *filename, unsigned int line, const char *msg) {
1023 	/* can't use buffer here; could lead to recursive assertions */
1024 	fprintf(stderr, "%s.%u: %s\n", filename, line, msg);
1025 	print_backtrace(stderr);
1026 	fflush(stderr);
1027 	abort();
1028 }
1029