xref: /lighttpd1.4/src/buffer.c (revision 2d94d56f)
1 #include "first.h"
2 
3 #include "buffer.h"
4 
5 #include <stdlib.h>
6 #include <string.h>
7 #include <time.h>       /* strftime() */
8 
9 static const char hex_chars_lc[] = "0123456789abcdef";
10 static const char hex_chars_uc[] = "0123456789ABCDEF";
11 
12 /**
13  * init the buffer
14  *
15  */
16 
17 buffer* buffer_init(void) {
18 	buffer *b;
19 
20 	b = malloc(sizeof(*b));
21 	force_assert(b);
22 
23 	b->ptr = NULL;
24 	b->size = 0;
25 	b->used = 0;
26 
27 	return b;
28 }
29 
30 buffer *buffer_init_buffer(const buffer *src) {
31 	buffer *b = buffer_init();
32 	buffer_copy_buffer(b, src);
33 	return b;
34 }
35 
36 buffer *buffer_init_string(const char *str) {
37 	buffer *b = buffer_init();
38 	buffer_copy_string(b, str);
39 	return b;
40 }
41 
42 void buffer_free(buffer *b) {
43 	if (NULL == b) return;
44 
45 	free(b->ptr);
46 	free(b);
47 }
48 
49 void buffer_free_ptr(buffer *b) {
50 	free(b->ptr);
51 	b->ptr = NULL;
52 	b->used = 0;
53 	b->size = 0;
54 }
55 
56 void buffer_move(buffer * restrict b, buffer * restrict src) {
57 	buffer tmp;
58 	force_assert(NULL != b);
59 	force_assert(NULL != src);
60 
61 	buffer_clear(b);
62 	tmp = *src; *src = *b; *b = tmp;
63 }
64 
65 /* make sure buffer is at least "size" big + 1 for '\0'. keep old data */
66 __attribute_cold__
67 static void buffer_realloc(buffer * const b, const size_t len) {
68     #define BUFFER_PIECE_SIZE 64uL  /*(must be power-of-2)*/
69     const size_t sz = (len + 1 + BUFFER_PIECE_SIZE-1) & ~(BUFFER_PIECE_SIZE-1);
70     force_assert(sz > len);
71 
72     b->size = sz;
73     b->ptr = realloc(b->ptr, sz);
74 
75     force_assert(NULL != b->ptr);
76 }
77 
78 __attribute_cold__
79 __attribute_noinline__
80 static void buffer_alloc_replace(buffer * const b, const size_t size) {
81     force_assert(NULL != b);
82     /*(discard old data so realloc() does not copy)*/
83     if (NULL != b->ptr) {
84         free(b->ptr);
85         b->ptr = NULL;
86     }
87     buffer_realloc(b, size);
88 }
89 
90 char* buffer_string_prepare_copy(buffer * const b, const size_t size) {
91 	if (NULL == b->ptr || size >= b->size) buffer_alloc_replace(b, size);
92 
93 	b->used = 0;
94 	return b->ptr;
95 }
96 
97 __attribute_cold__
98 __attribute_noinline__
99 __attribute_returns_nonnull__
100 static char* buffer_string_prepare_append_resize(buffer * const b, const size_t size) {
101 	force_assert(NULL !=  b);
102 	if (buffer_string_is_empty(b)) {
103 		return buffer_string_prepare_copy(b, size);
104 	} else {
105 		/* not empty, b->used already includes a terminating 0 */
106 		size_t req_size = b->used + size;
107 
108 		/* check for overflow: unsigned overflow is defined to wrap around */
109 		force_assert(req_size >= b->used);
110 
111 		buffer_realloc(b, req_size);
112 
113 		return b->ptr + b->used - 1;
114 	}
115 }
116 
117 char* buffer_string_prepare_append(buffer * const b, const size_t size) {
118     return (NULL != b->ptr && size < b->size - b->used)
119       ? b->ptr + b->used - (0 != b->used)
120       : buffer_string_prepare_append_resize(b, size);
121 }
122 
123 void buffer_string_set_length(buffer *b, uint32_t len) {
124 	force_assert(NULL != b);
125 
126 	if (len >= b->size) buffer_realloc(b, len);
127 
128 	b->used = len + 1;
129 	b->ptr[len] = '\0';
130 }
131 
132 void buffer_commit(buffer *b, size_t size)
133 {
134 	force_assert(NULL != b);
135 	force_assert(b->size > 0);
136 
137 	if (0 == b->used) b->used = 1;
138 
139 	if (size > 0) {
140 		/* check for overflow: unsigned overflow is defined to wrap around */
141 		size_t sz = b->used + size;
142 		force_assert(sz > b->used);
143 		force_assert(sz <= b->size);
144 		b->used = sz;
145 	}
146 
147 	b->ptr[b->used - 1] = '\0';
148 }
149 
150 void buffer_copy_string(buffer * restrict b, const char * restrict s) {
151 	buffer_copy_string_len(b, s, NULL != s ? strlen(s) : 0);
152 }
153 
154 void buffer_copy_string_len(buffer * const restrict b, const char * const restrict s, const size_t s_len) {
155 	if (NULL == b->ptr || s_len >= b->size) buffer_alloc_replace(b, s_len);
156 
157 	b->used = s_len + 1;
158 	b->ptr[s_len] = '\0';
159 	if (0 != s_len) memcpy(b->ptr, s, s_len); /*(s might be NULL)*/
160 }
161 
162 void buffer_append_string(buffer * restrict b, const char * restrict s) {
163 	buffer_append_string_len(b, s, NULL != s ? strlen(s) : 0);
164 }
165 
166 /**
167  * append a string to the end of the buffer
168  *
169  * the resulting buffer is terminated with a '\0'
170  * s is treated as a un-terminated string (a \0 is handled a normal character)
171  *
172  * @param b a buffer
173  * @param s the string
174  * @param s_len size of the string (without the terminating \0)
175  */
176 
177 void buffer_append_string_len(buffer * const restrict b, const char * const restrict s, const size_t s_len) {
178 	char * const target_buf = buffer_string_prepare_append(b, s_len);
179 	b->used += s_len + (0 == b->used); /*(must include '\0' for append)*/
180 	target_buf[s_len] = '\0';
181 
182 	/*(s might be NULL if 0 == s_len)*/
183 	if (s_len) memcpy(target_buf, s, s_len);
184 }
185 
186 void buffer_append_path_len(buffer * restrict b, const char * restrict a, size_t alen) {
187     size_t blen = buffer_string_length(b);
188     int aslash = (alen && a[0] == '/');
189     buffer_string_prepare_append(b, alen+2); /*(+ '/' and + '\0' if 0 == blen)*/
190     if (blen && b->ptr[blen-1] == '/') {
191         if (aslash) --b->used;
192     }
193     else {
194         if (!b->used) ++b->used;
195         if (!aslash) b->ptr[++b->used - 2] = '/';
196     }
197     memcpy(b->ptr+b->used-1, a, alen);
198     b->ptr[(b->used += alen)-1] = '\0';
199 }
200 
201 void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
202 	char *buf;
203 	unsigned int shift = 0;
204 
205 	{
206 		uintmax_t copy = value;
207 		do {
208 			copy >>= 8;
209 			shift += 8; /* counting bits */
210 		} while (0 != copy);
211 	}
212 
213 	buf = buffer_string_prepare_append(b, shift >> 2); /*nibbles (4 bits)*/
214 	buffer_commit(b, shift >> 2); /* will fill below */
215 
216 	while (shift > 0) {
217 		shift -= 4;
218 		*(buf++) = hex_chars_lc[(value >> shift) & 0x0F];
219 	}
220 }
221 
222 __attribute_returns_nonnull__
223 static char* utostr(char * const buf_end, uintmax_t val) {
224 	char *cur = buf_end;
225 	do {
226 		int mod = val % 10;
227 		val /= 10;
228 		/* prepend digit mod */
229 		*(--cur) = (char) ('0' + mod);
230 	} while (0 != val);
231 	return cur;
232 }
233 
234 __attribute_returns_nonnull__
235 static char* itostr(char * const buf_end, intmax_t val) {
236 	/* absolute value not defined for INTMAX_MIN, but can take absolute
237 	 * value of any negative number via twos complement cast to unsigned.
238 	 * negative sign is prepended after (now unsigned) value is converted
239 	 * to string */
240 	uintmax_t uval = val >= 0 ? (uintmax_t)val : ((uintmax_t)~val) + 1;
241 	char *cur = utostr(buf_end, uval);
242 	if (val < 0) *(--cur) = '-';
243 
244 	return cur;
245 }
246 
247 void buffer_append_int(buffer *b, intmax_t val) {
248 	char buf[LI_ITOSTRING_LENGTH];
249 	char* const buf_end = buf + sizeof(buf);
250 	char *str;
251 
252 	force_assert(NULL != b);
253 
254 	str = itostr(buf_end, val);
255 	force_assert(buf_end > str && str >= buf);
256 
257 	buffer_append_string_len(b, str, buf_end - str);
258 }
259 
260 void buffer_append_strftime(buffer * const restrict b, const char * const restrict format, const struct tm * const restrict tm) {
261 	size_t rv;
262 	char* buf;
263 	force_assert(NULL != format);
264 	if (NULL == tm) return;
265 
266 	buf = buffer_string_prepare_append(b, 255);
267 	rv = strftime(buf, buffer_string_space(b), format, tm);
268 
269 	/* 0 (in some apis buffer_string_space(b)) signals the string may have
270 	 * been too small; but the format could also just have lead to an empty
271 	 * string
272 	 */
273 	if (0 == rv || rv >= buffer_string_space(b)) {
274 		/* give it a second try with a larger string */
275 		buf = buffer_string_prepare_append(b, 4095);
276 		rv = strftime(buf, buffer_string_space(b), format, tm);
277 	}
278 
279 	if (rv >= buffer_string_space(b)) rv = 0;
280 
281 	buffer_commit(b, rv);
282 }
283 
284 
285 size_t li_itostrn(char *buf, size_t buf_len, intmax_t val) {
286 	char p_buf[LI_ITOSTRING_LENGTH];
287 	char* const str = itostr(p_buf+sizeof(p_buf), val);
288 	size_t len = (size_t)(p_buf+sizeof(p_buf)-str);
289 	force_assert(len <= buf_len);
290 	memcpy(buf, str, len);
291 	return len;
292 }
293 
294 size_t li_utostrn(char *buf, size_t buf_len, uintmax_t val) {
295 	char p_buf[LI_ITOSTRING_LENGTH];
296 	char* const str = utostr(p_buf+sizeof(p_buf), val);
297 	size_t len = (size_t)(p_buf+sizeof(p_buf)-str);
298 	force_assert(len <= buf_len);
299 	memcpy(buf, str, len);
300 	return len;
301 }
302 
303 #define li_ntox_lc(n) ((n) <= 9 ? (n) + '0' : (n) + 'a' - 10)
304 
305 char int2hex(char c) {
306 	/*return li_ntox_lc(c & 0xF);*/
307 	return hex_chars_lc[(c & 0x0F)];
308 }
309 
310 /* c (char) and n (nibble) MUST be unsigned integer types */
311 #define li_cton(c,n) \
312   (((n) = (c) - '0') <= 9 || (((n) = ((c)&0xdf) - 'A') <= 5 ? ((n) += 10) : 0))
313 
314 /* converts hex char (0-9, A-Z, a-z) to decimal.
315  * returns 0xFF on invalid input.
316  */
317 char hex2int(unsigned char hex) {
318 	unsigned char n;
319 	return li_cton(hex,n) ? (char)n : 0xFF;
320 }
321 
322 
323 int buffer_eq_icase_ssn(const char * const a, const char * const b, const size_t len) {
324     for (size_t i = 0; i < len; ++i) {
325         unsigned int ca = ((unsigned char *)a)[i];
326         unsigned int cb = ((unsigned char *)b)[i];
327         if (ca != cb) {
328             ca |= 0x20;
329             cb |= 0x20;
330             if (ca != cb) return 0;
331             if (!light_islower(ca)) return 0;
332             if (!light_islower(cb)) return 0;
333         }
334     }
335     return 1;
336 }
337 
338 int buffer_eq_icase_ss(const char * const a, const size_t alen, const char * const b, const size_t blen) {
339     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
340     return (alen == blen && buffer_eq_icase_ssn(a, b, blen));
341 }
342 
343 int buffer_eq_icase_slen(const buffer * const b, const char * const s, const size_t slen) {
344     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
345     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
346     return (b->used == slen + 1 && buffer_eq_icase_ssn(b->ptr, s, slen));
347 }
348 
349 int buffer_eq_slen(const buffer * const b, const char * const s, const size_t slen) {
350     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
351     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
352     return (b->used == slen + 1 && 0 == memcmp(b->ptr, s, slen));
353 }
354 
355 
356 /**
357  * check if two buffer contain the same data
358  */
359 
360 int buffer_is_equal(const buffer *a, const buffer *b) {
361 	force_assert(NULL != a && NULL != b);
362 
363 	/* 1 = equal; 0 = not equal */
364 	return (a->used == b->used && 0 == memcmp(a->ptr, b->ptr, a->used));
365 }
366 
367 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len) {
368 	force_assert(NULL != a && NULL != s);
369 	force_assert(b_len + 1 > b_len);
370 
371 	/* 1 = equal; 0 = not equal */
372 	return (a->used == b_len + 1 && 0 == memcmp(a->ptr, s, b_len));
373 }
374 
375 int buffer_is_equal_right_len(const buffer *b1, const buffer *b2, size_t len) {
376 	/* no len -> equal */
377 	if (len == 0) return 1;
378 
379 	/* len > 0, but empty buffers -> not equal */
380 	if (b1->used == 0 || b2->used == 0) return 0;
381 
382 	/* buffers too small -> not equal */
383 	if (b1->used - 1 < len || b2->used - 1 < len) return 0;
384 
385 	return 0 == memcmp(b1->ptr + b1->used - 1 - len, b2->ptr + b2->used - 1 - len, len);
386 }
387 
388 
389 void li_tohex_lc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
390 	force_assert(2 * s_len > s_len);
391 	force_assert(2 * s_len < buf_len);
392 
393 	for (size_t i = 0; i < s_len; ++i) {
394 		buf[2*i]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
395 		buf[2*i+1] = hex_chars_lc[s[i] & 0x0F];
396 	}
397 	buf[2*s_len] = '\0';
398 }
399 
400 void li_tohex_uc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
401 	force_assert(2 * s_len > s_len);
402 	force_assert(2 * s_len < buf_len);
403 
404 	for (size_t i = 0; i < s_len; ++i) {
405 		buf[2*i]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
406 		buf[2*i+1] = hex_chars_uc[s[i] & 0x0F];
407 	}
408 	buf[2*s_len] = '\0';
409 }
410 
411 
412 void buffer_substr_replace (buffer * const restrict b, const size_t offset,
413                             const size_t len, const buffer * const restrict replace)
414 {
415     const size_t blen = buffer_string_length(b);
416     const size_t rlen = buffer_string_length(replace);
417 
418     if (rlen > len) {
419         buffer_string_set_length(b, blen-len+rlen);
420         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
421     }
422 
423     memcpy(b->ptr+offset, replace->ptr, rlen);
424 
425     if (rlen < len) {
426         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
427         buffer_string_set_length(b, blen-len+rlen);
428     }
429 }
430 
431 
432 void buffer_append_string_encoded_hex_lc(buffer * const restrict b, const char * const restrict s, size_t len) {
433     unsigned char * const p =
434       (unsigned char*) buffer_string_prepare_append(b, len*2);
435     buffer_commit(b, len*2); /* fill below */
436     for (size_t i = 0; i < len; ++i) {
437         p[(i<<1)]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
438         p[(i<<1)+1] = hex_chars_lc[(s[i])      & 0x0F];
439     }
440 }
441 
442 void buffer_append_string_encoded_hex_uc(buffer * const restrict b, const char * const restrict s, size_t len) {
443     unsigned char * const p =
444       (unsigned char*) buffer_string_prepare_append(b, len*2);
445     buffer_commit(b, len*2); /* fill below */
446     for (size_t i = 0; i < len; ++i) {
447         p[(i<<1)]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
448         p[(i<<1)+1] = hex_chars_uc[(s[i])      & 0x0F];
449     }
450 }
451 
452 
453 /* everything except: ! ( ) * - . 0-9 A-Z _ a-z */
454 static const char encoded_chars_rel_uri_part[] = {
455 	/*
456 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
457 	*/
458 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
459 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
460 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1,  /*  20 -  2F space " # $ % & ' + , / */
461 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
462 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
463 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
464 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
465 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
466 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
467 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
468 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
469 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
470 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
471 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
472 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
473 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
474 };
475 
476 /* everything except: ! ( ) * - . / 0-9 A-Z _ a-z */
477 static const char encoded_chars_rel_uri[] = {
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, 0,  /*  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 static const char encoded_chars_html[] = {
500 	/*
501 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
502 	*/
503 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
504 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
505 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
506 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
507 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
508 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
509 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
510 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
511 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
512 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
513 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
514 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
515 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
516 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
517 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
518 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
519 };
520 
521 static const char encoded_chars_minimal_xml[] = {
522 	/*
523 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
524 	*/
525 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
526 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
527 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
528 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
529 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
530 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
531 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
532 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
533 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  80 -  8F */
534 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  90 -  9F */
535 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  A0 -  AF */
536 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  B0 -  BF */
537 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  C0 -  CF */
538 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  D0 -  DF */
539 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  E0 -  EF */
540 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  F0 -  FF */
541 };
542 
543 
544 
545 void buffer_append_string_encoded(buffer * const restrict b, const char * const restrict s, size_t s_len, buffer_encoding_t encoding) {
546 	unsigned char *ds, *d;
547 	size_t d_len, ndx;
548 	const char *map = NULL;
549 
550 	if (0 == s_len) return;
551 
552 	force_assert(NULL != s);
553 
554 	switch(encoding) {
555 	case ENCODING_REL_URI:
556 		map = encoded_chars_rel_uri;
557 		break;
558 	case ENCODING_REL_URI_PART:
559 		map = encoded_chars_rel_uri_part;
560 		break;
561 	case ENCODING_HTML:
562 		map = encoded_chars_html;
563 		break;
564 	case ENCODING_MINIMAL_XML:
565 		map = encoded_chars_minimal_xml;
566 		break;
567 	}
568 
569 	force_assert(NULL != map);
570 
571 	/* count to-be-encoded-characters */
572 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
573 		if (map[*ds & 0xFF]) {
574 			switch(encoding) {
575 			case ENCODING_REL_URI:
576 			case ENCODING_REL_URI_PART:
577 				d_len += 3;
578 				break;
579 			case ENCODING_HTML:
580 			case ENCODING_MINIMAL_XML:
581 				d_len += 6;
582 				break;
583 			}
584 		} else {
585 			d_len++;
586 		}
587 	}
588 
589 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
590 	buffer_commit(b, d_len); /* fill below */
591 
592 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
593 		if (map[*ds & 0xFF]) {
594 			switch(encoding) {
595 			case ENCODING_REL_URI:
596 			case ENCODING_REL_URI_PART:
597 				d[d_len++] = '%';
598 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
599 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
600 				break;
601 			case ENCODING_HTML:
602 			case ENCODING_MINIMAL_XML:
603 				d[d_len++] = '&';
604 				d[d_len++] = '#';
605 				d[d_len++] = 'x';
606 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
607 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
608 				d[d_len++] = ';';
609 				break;
610 			}
611 		} else {
612 			d[d_len++] = *ds;
613 		}
614 	}
615 }
616 
617 void buffer_append_string_c_escaped(buffer * const restrict b, const char * const restrict s, size_t s_len) {
618 	unsigned char *ds, *d;
619 	size_t d_len, ndx;
620 
621 	if (0 == s_len) return;
622 
623 	force_assert(NULL != s);
624 
625 	/* count to-be-encoded-characters */
626 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
627 		if ((*ds < 0x20) /* control character */
628 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
629 			switch (*ds) {
630 			case '\t':
631 			case '\r':
632 			case '\n':
633 				d_len += 2;
634 				break;
635 			default:
636 				d_len += 4; /* \xCC */
637 				break;
638 			}
639 		} else {
640 			d_len++;
641 		}
642 	}
643 
644 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
645 	buffer_commit(b, d_len); /* fill below */
646 
647 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
648 		if ((*ds < 0x20) /* control character */
649 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
650 			d[d_len++] = '\\';
651 			switch (*ds) {
652 			case '\t':
653 				d[d_len++] = 't';
654 				break;
655 			case '\r':
656 				d[d_len++] = 'r';
657 				break;
658 			case '\n':
659 				d[d_len++] = 'n';
660 				break;
661 			default:
662 				d[d_len++] = 'x';
663 				d[d_len++] = hex_chars_lc[((*ds) >> 4) & 0x0F];
664 				d[d_len++] = hex_chars_lc[(*ds) & 0x0F];
665 				break;
666 			}
667 		} else {
668 			d[d_len++] = *ds;
669 		}
670 	}
671 }
672 
673 
674 void buffer_copy_string_encoded_cgi_varnames(buffer * const restrict b, const char * const restrict s, size_t s_len, int is_http_header) {
675 	size_t i, j = 0;
676 
677 	force_assert(NULL != b);
678 	force_assert(NULL != s || 0 == s_len);
679 
680 	buffer_string_prepare_copy(b, s_len + 5);
681 
682 	if (is_http_header) {
683 		if (s_len == 12 && buffer_eq_icase_ssn(s, "Content-Type", 12)) {
684 			buffer_copy_string_len(b, CONST_STR_LEN("CONTENT_TYPE"));
685 			return;
686 		}
687 		buffer_copy_string_len(b, CONST_STR_LEN("HTTP_"));
688 		j = 5; /* "HTTP_" */
689 	}
690 
691 	for (i = 0; i < s_len; ++i) {
692 		unsigned char cr = s[i];
693 		if (light_isalpha(cr)) {
694 			/* upper-case */
695 			cr &= ~32;
696 		} else if (!light_isdigit(cr)) {
697 			cr = '_';
698 		}
699 		b->ptr[j++] = cr;
700 	}
701 	b->used = j;
702 	b->ptr[b->used++] = '\0';
703 }
704 
705 /* decodes url-special-chars inplace.
706  * replaces non-printable characters with '_'
707  */
708 
709 static void buffer_urldecode_internal(buffer * const url, const int is_query) {
710 	unsigned char high, low;
711 	char *src;
712 	char *dst;
713 
714 	force_assert(NULL != url);
715 	if (buffer_string_is_empty(url)) return;
716 
717 	force_assert('\0' == url->ptr[url->used-1]);
718 
719 	src = (char*) url->ptr;
720 
721 	if (!is_query) {
722 		while ('\0' != *src && '%' != *src) ++src;
723 	}
724 	else {
725 		for (; '\0' != *src && '%' != *src; ++src) {
726 			if ('+' == *src) *src = ' ';
727 		}
728 	}
729 
730 	if ('\0' == *src) return;
731 
732 	dst = src;
733 
734 	while ('\0' != *src) {
735 		if (is_query && *src == '+') {
736 			*dst = ' ';
737 		} else if (*src == '%') {
738 			*dst = '%';
739 
740 			high = hex2int(*(src + 1));
741 			if (0xFF != high) {
742 				low = hex2int(*(src + 2));
743 				if (0xFF != low) {
744 					high = (high << 4) | low;
745 
746 					/* map control-characters out */
747 					if (high < 32 || high == 127) high = '_';
748 
749 					*dst = high;
750 					src += 2;
751 				}
752 			}
753 		} else {
754 			*dst = *src;
755 		}
756 
757 		dst++;
758 		src++;
759 	}
760 
761 	*dst = '\0';
762 	url->used = (dst - url->ptr) + 1;
763 }
764 
765 void buffer_urldecode_path(buffer *url) {
766 	buffer_urldecode_internal(url, 0);
767 }
768 
769 void buffer_urldecode_query(buffer *url) {
770 	buffer_urldecode_internal(url, 1);
771 }
772 
773 int buffer_is_valid_UTF8(const buffer *b) {
774     /* https://www.w3.org/International/questions/qa-forms-utf-8 */
775     const unsigned char *c = (unsigned char *)b->ptr;
776     while (*c) {
777 
778         /*(note: includes ctrls)*/
779         if (                         c[0] <  0x80 ) { ++c;  continue; }
780 
781         if (         0xc2 <= c[0] && c[0] <= 0xdf
782             &&       0x80 <= c[1] && c[1] <= 0xbf ) { c+=2; continue; }
783 
784         if ( (   (   0xe0 == c[0]
785                   && 0xa0 <= c[1] && c[1] <= 0xbf)
786               || (   0xe1 <= c[0] && c[0] <= 0xef && c[0] != 0xed
787                   && 0x80 <= c[1] && c[1] <= 0xbf)
788               || (   0xed == c[0]
789                   && 0x80 <= c[1] && c[1] <= 0x9f)   )
790             &&       0x80 <= c[2] && c[2] <= 0xbf ) { c+=3; continue; }
791 
792         if ( (   (   0xf0 == c[0]
793                   && 0x90 <= c[1] && c[1] <= 0xbf)
794               || (   0xf1 <= c[0] && c[0] <= 0xf3
795                   && 0x80 <= c[1] && c[1] <= 0xbf)
796               || (   0xf4 == c[0]
797                   && 0x80 <= c[1] && c[1] <= 0x8f)   )
798             &&       0x80 <= c[2] && c[2] <= 0xbf
799             &&       0x80 <= c[3] && c[3] <= 0xbf ) { c+=4; continue; }
800 
801         return 0; /* invalid */
802     }
803     return 1; /* valid */
804 }
805 
806 /* - special case: empty string returns empty string
807  * - on windows or cygwin: replace \ with /
808  * - strip leading spaces
809  * - prepends "/" if not present already
810  * - resolve "/../", "//" and "/./" the usual way:
811  *   the first one removes a preceding component, the other two
812  *   get compressed to "/".
813  * - "/." and "/.." at the end are similar, but always leave a trailing
814  *   "/"
815  *
816  * /blah/..         gets  /
817  * /blah/../foo     gets  /foo
818  * /abc/./xyz       gets  /abc/xyz
819  * /abc//xyz        gets  /abc/xyz
820  *
821  * NOTE: src and dest can point to the same buffer, in which case,
822  *       the operation is performed in-place.
823  */
824 
825 void buffer_path_simplify(buffer *dest, buffer *src)
826 {
827 	/* current character, the one before, and the one before that from input */
828 	char c, pre1, pre2;
829 	char *start, *slash, *walk, *out;
830 
831 	force_assert(NULL != dest && NULL != src);
832 
833 	if (buffer_string_is_empty(src)) {
834 		buffer_copy_string_len(dest, CONST_STR_LEN(""));
835 		return;
836 	}
837 
838 	force_assert('\0' == src->ptr[src->used-1]);
839 
840 #if defined(__WIN32) || defined(__CYGWIN__)
841 	/* cygwin is treating \ and / the same, so we have to that too */
842 	{
843 		char *p;
844 		for (p = src->ptr; *p; p++) {
845 			if (*p == '\\') *p = '/';
846 		}
847 	}
848 #endif
849 
850 	walk  = src->ptr;
851 	start = dest->ptr;
852 	out   = dest->ptr;
853 	slash = dest->ptr;
854 
855 	/* skip leading spaces */
856 	while (*walk == ' ') {
857 		walk++;
858 	}
859 	if (*walk == '.') {
860 		if (walk[1] == '/' || walk[1] == '\0')
861 			++walk;
862 		else if (walk[1] == '.' && (walk[2] == '/' || walk[2] == '\0'))
863 			walk+=2;
864 	}
865 
866 	pre1 = 0;
867 	c = *(walk++);
868 
869 	while (c != '\0') {
870 		/* assert((src != dest || out <= walk) && slash <= out); */
871 		/* the following comments about out and walk are only interesting if
872 		 * src == dest; otherwise the memory areas don't overlap anyway.
873 		 */
874 		pre2 = pre1;
875 		pre1 = c;
876 
877 		/* possibly: out == walk - need to read first */
878 		c    = *walk;
879 		*out = pre1;
880 
881 		out++;
882 		walk++;
883 		/* (out <= walk) still true; also now (slash < out) */
884 
885 		if (c == '/' || c == '\0') {
886 			const size_t toklen = out - slash;
887 			if (toklen == 3 && pre2 == '.' && pre1 == '.' && *slash == '/') {
888 				/* "/../" or ("/.." at end of string) */
889 				out = slash;
890 				/* if there is something before "/..", there is at least one
891 				 * component, which needs to be removed */
892 				if (out > start) {
893 					out--;
894 					while (out > start && *out != '/') out--;
895 				}
896 
897 				/* don't kill trailing '/' at end of path */
898 				if (c == '\0') out++;
899 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
900 			} else if (toklen == 1 || (pre2 == '/' && pre1 == '.')) {
901 				/* "//" or "/./" or (("/" or "/.") at end of string) */
902 				out = slash;
903 				/* don't kill trailing '/' at end of path */
904 				if (c == '\0') out++;
905 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
906 			}
907 
908 			slash = out;
909 		}
910 	}
911 
912 	buffer_string_set_length(dest, out - start);
913 }
914 
915 void buffer_to_lower(buffer * const b) {
916     unsigned char * const restrict s = (unsigned char *)b->ptr;
917     for (uint32_t i = 0; i < b->used; ++i) {
918         if (light_isupper(s[i])) s[i] |= 0x20;
919     }
920 }
921 
922 
923 void buffer_to_upper(buffer * const b) {
924     unsigned char * const restrict s = (unsigned char *)b->ptr;
925     for (uint32_t i = 0; i < b->used; ++i) {
926         if (light_islower(s[i])) s[i] &= 0xdf;
927     }
928 }
929 
930 
931 #include <stdio.h>
932 
933 #ifdef HAVE_LIBUNWIND
934 # define UNW_LOCAL_ONLY
935 # include <libunwind.h>
936 
937 static void print_backtrace(FILE *file) {
938 	unw_cursor_t cursor;
939 	unw_context_t context;
940 	int ret;
941 	unsigned int frame = 0;
942 
943 	if (0 != (ret = unw_getcontext(&context))) goto error;
944 	if (0 != (ret = unw_init_local(&cursor, &context))) goto error;
945 
946 	fprintf(file, "Backtrace:\n");
947 
948 	while (0 < (ret = unw_step(&cursor))) {
949 		unw_word_t proc_ip = 0;
950 		unw_proc_info_t procinfo;
951 		char procname[256];
952 		unw_word_t proc_offset = 0;
953 
954 		if (0 != (ret = unw_get_reg(&cursor, UNW_REG_IP, &proc_ip))) goto error;
955 
956 		if (0 == proc_ip) {
957 			/* without an IP the other functions are useless; unw_get_proc_name would return UNW_EUNSPEC */
958 			++frame;
959 			fprintf(file, "%u: (nil)\n", frame);
960 			continue;
961 		}
962 
963 		if (0 != (ret = unw_get_proc_info(&cursor, &procinfo))) goto error;
964 
965 		if (0 != (ret = unw_get_proc_name(&cursor, procname, sizeof(procname), &proc_offset))) {
966 			switch (-ret) {
967 			case UNW_ENOMEM:
968 				memset(procname + sizeof(procname) - 4, '.', 3);
969 				procname[sizeof(procname) - 1] = '\0';
970 				break;
971 			case UNW_ENOINFO:
972 				procname[0] = '?';
973 				procname[1] = '\0';
974 				proc_offset = 0;
975 				break;
976 			default:
977 				snprintf(procname, sizeof(procname), "?? (unw_get_proc_name error %d)", -ret);
978 				break;
979 			}
980 		}
981 
982 		++frame;
983 		fprintf(file, "%u: %s (+0x%x) [%p]\n",
984 			frame,
985 			procname,
986 			(unsigned int) proc_offset,
987 			(void*)(uintptr_t)proc_ip);
988 	}
989 
990 	if (0 != ret) goto error;
991 
992 	return;
993 
994 error:
995 	fprintf(file, "Error while generating backtrace: unwind error %i\n", (int) -ret);
996 }
997 #else
998 static void print_backtrace(FILE *file) {
999 	UNUSED(file);
1000 }
1001 #endif
1002 
1003 void log_failed_assert(const char *filename, unsigned int line, const char *msg) {
1004 	/* can't use buffer here; could lead to recursive assertions */
1005 	fprintf(stderr, "%s.%u: %s\n", filename, line, msg);
1006 	print_backtrace(stderr);
1007 	fflush(stderr);
1008 	abort();
1009 }
1010