xref: /lighttpd1.4/src/buffer.c (revision 48e272b3)
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 	free(b->ptr);
53 	b->ptr = NULL;
54 	b->used = 0;
55 	b->size = 0;
56 }
57 
58 void buffer_reset(buffer *b) {
59 	force_assert(NULL != b);
60 	b->used = 0;
61 	/* release buffer larger than ... bytes */
62 	if (b->size > BUFFER_MAX_REUSE_SIZE) buffer_free_ptr(b);
63 }
64 
65 void buffer_move(buffer * restrict b, buffer * restrict src) {
66 	buffer tmp;
67 	force_assert(NULL != b);
68 	force_assert(NULL != src);
69 
70 	buffer_clear(b);
71 	tmp = *src; *src = *b; *b = tmp;
72 }
73 
74 /* make sure buffer is at least "size" big + 1 for '\0'. keep old data */
75 __attribute_cold__
76 static void buffer_realloc(buffer * const b, const size_t len) {
77     #define BUFFER_PIECE_SIZE 64uL  /*(must be power-of-2)*/
78     const size_t sz = (len + 1 + BUFFER_PIECE_SIZE-1) & ~(BUFFER_PIECE_SIZE-1);
79     force_assert(sz > len);
80 
81     b->size = sz;
82     b->ptr = realloc(b->ptr, sz);
83 
84     force_assert(NULL != b->ptr);
85 }
86 
87 __attribute_cold__
88 __attribute_noinline__
89 static void buffer_alloc_replace(buffer * const b, const size_t size) {
90     force_assert(NULL != b);
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 * const b, const size_t size) {
100 	if (NULL == b || size >= b->size) buffer_alloc_replace(b, size);
101 
102 	b->used = 0;
103 	return b->ptr;
104 }
105 
106 __attribute_cold__
107 __attribute_noinline__
108 __attribute_returns_nonnull__
109 static char* buffer_string_prepare_append_resize(buffer * const b, const size_t size) {
110 	force_assert(NULL !=  b);
111 	if (buffer_string_is_empty(b)) {
112 		return buffer_string_prepare_copy(b, size);
113 	} else {
114 		/* not empty, b->used already includes a terminating 0 */
115 		size_t req_size = b->used + size;
116 
117 		/* check for overflow: unsigned overflow is defined to wrap around */
118 		force_assert(req_size >= b->used);
119 
120 		buffer_realloc(b, req_size);
121 
122 		return b->ptr + b->used - 1;
123 	}
124 }
125 
126 char* buffer_string_prepare_append(buffer * const b, const size_t size) {
127     return (NULL != b && size < b->size - b->used)
128       ? b->ptr + b->used - (0 != b->used)
129       : buffer_string_prepare_append_resize(b, size);
130 }
131 
132 void buffer_string_set_length(buffer *b, uint32_t len) {
133 	force_assert(NULL != b);
134 
135 	if (len >= b->size) buffer_realloc(b, len);
136 
137 	b->used = len + 1;
138 	b->ptr[len] = '\0';
139 }
140 
141 void buffer_commit(buffer *b, size_t size)
142 {
143 	force_assert(NULL != b);
144 	force_assert(b->size > 0);
145 
146 	if (0 == b->used) b->used = 1;
147 
148 	if (size > 0) {
149 		/* check for overflow: unsigned overflow is defined to wrap around */
150 		size_t sz = b->used + size;
151 		force_assert(sz > b->used);
152 		force_assert(sz <= b->size);
153 		b->used = sz;
154 	}
155 
156 	b->ptr[b->used - 1] = '\0';
157 }
158 
159 void buffer_copy_string(buffer * restrict b, const char * restrict s) {
160 	buffer_copy_string_len(b, s, NULL != s ? strlen(s) : 0);
161 }
162 
163 void buffer_copy_string_len(buffer * const restrict b, const char * const restrict s, const size_t s_len) {
164 	if (NULL == b || s_len >= b->size) buffer_alloc_replace(b, s_len);
165 
166 	b->used = s_len + 1;
167 	b->ptr[s_len] = '\0';
168 	if (0 != s_len) memcpy(b->ptr, s, s_len); /*(s might be NULL)*/
169 }
170 
171 void buffer_append_string(buffer * restrict b, const char * restrict 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 * const restrict b, const char * const restrict s, const size_t s_len) {
187 	char * const target_buf = buffer_string_prepare_append(b, s_len);
188 	b->used += s_len + (0 == b->used); /*(must include '\0' for append)*/
189 	target_buf[s_len] = '\0';
190 
191 	/*(s might be NULL if 0 == s_len)*/
192 	if (s_len) memcpy(target_buf, s, s_len);
193 }
194 
195 void buffer_append_path_len(buffer * restrict b, const char * restrict a, size_t alen) {
196     size_t blen = buffer_string_length(b);
197     int aslash = (alen && a[0] == '/');
198     buffer_string_prepare_append(b, alen+2); /*(+ '/' and + '\0' if 0 == blen)*/
199     if (blen && b->ptr[blen-1] == '/') {
200         if (aslash) --b->used;
201     }
202     else {
203         if (!b->used) ++b->used;
204         if (!aslash) b->ptr[++b->used - 2] = '/';
205     }
206     memcpy(b->ptr+b->used-1, a, alen);
207     b->ptr[(b->used += alen)-1] = '\0';
208 }
209 
210 void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
211 	char *buf;
212 	unsigned int shift = 0;
213 
214 	{
215 		uintmax_t copy = value;
216 		do {
217 			copy >>= 8;
218 			shift += 8; /* counting bits */
219 		} while (0 != copy);
220 	}
221 
222 	buf = buffer_string_prepare_append(b, shift >> 2); /*nibbles (4 bits)*/
223 	buffer_commit(b, shift >> 2); /* will fill below */
224 
225 	while (shift > 0) {
226 		shift -= 4;
227 		*(buf++) = hex_chars_lc[(value >> shift) & 0x0F];
228 	}
229 }
230 
231 __attribute_returns_nonnull__
232 static char* utostr(char * const buf_end, uintmax_t val) {
233 	char *cur = buf_end;
234 	do {
235 		int mod = val % 10;
236 		val /= 10;
237 		/* prepend digit mod */
238 		*(--cur) = (char) ('0' + mod);
239 	} while (0 != val);
240 	return cur;
241 }
242 
243 __attribute_returns_nonnull__
244 static char* itostr(char * const buf_end, intmax_t val) {
245 	/* absolute value not defined for INTMAX_MIN, but can take absolute
246 	 * value of any negative number via twos complement cast to unsigned.
247 	 * negative sign is prepended after (now unsigned) value is converted
248 	 * to string */
249 	uintmax_t uval = val >= 0 ? (uintmax_t)val : ((uintmax_t)~val) + 1;
250 	char *cur = utostr(buf_end, uval);
251 	if (val < 0) *(--cur) = '-';
252 
253 	return cur;
254 }
255 
256 void buffer_append_int(buffer *b, intmax_t val) {
257 	char buf[LI_ITOSTRING_LENGTH];
258 	char* const buf_end = buf + sizeof(buf);
259 	char *str;
260 
261 	force_assert(NULL != b);
262 
263 	str = itostr(buf_end, val);
264 	force_assert(buf_end > str && str >= buf);
265 
266 	buffer_append_string_len(b, str, buf_end - str);
267 }
268 
269 void buffer_append_strftime(buffer * const restrict b, const char * const restrict format, const struct tm * const restrict tm) {
270 	size_t rv;
271 	char* buf;
272 	force_assert(NULL != format);
273 	force_assert(NULL != tm);
274 
275 	buf = buffer_string_prepare_append(b, 255);
276 	rv = strftime(buf, buffer_string_space(b), format, tm);
277 
278 	/* 0 (in some apis buffer_string_space(b)) signals the string may have
279 	 * been too small; but the format could also just have lead to an empty
280 	 * string
281 	 */
282 	if (0 == rv || rv >= buffer_string_space(b)) {
283 		/* give it a second try with a larger string */
284 		buf = buffer_string_prepare_append(b, 4095);
285 		rv = strftime(buf, buffer_string_space(b), format, tm);
286 	}
287 
288 	if (rv >= buffer_string_space(b)) rv = 0;
289 
290 	buffer_commit(b, rv);
291 }
292 
293 
294 size_t li_itostrn(char *buf, size_t buf_len, intmax_t val) {
295 	char p_buf[LI_ITOSTRING_LENGTH];
296 	char* const str = itostr(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 size_t li_utostrn(char *buf, size_t buf_len, uintmax_t val) {
304 	char p_buf[LI_ITOSTRING_LENGTH];
305 	char* const str = utostr(p_buf+sizeof(p_buf), val);
306 	size_t len = (size_t)(p_buf+sizeof(p_buf)-str);
307 	force_assert(len <= buf_len);
308 	memcpy(buf, str, len);
309 	return len;
310 }
311 
312 #define li_ntox_lc(n) ((n) <= 9 ? (n) + '0' : (n) + 'a' - 10)
313 
314 char int2hex(char c) {
315 	/*return li_ntox_lc(c & 0xF);*/
316 	return hex_chars_lc[(c & 0x0F)];
317 }
318 
319 /* c (char) and n (nibble) MUST be unsigned integer types */
320 #define li_cton(c,n) \
321   (((n) = (c) - '0') <= 9 || (((n) = ((c)&0xdf) - 'A') <= 5 ? ((n) += 10) : 0))
322 
323 /* converts hex char (0-9, A-Z, a-z) to decimal.
324  * returns 0xFF on invalid input.
325  */
326 char hex2int(unsigned char hex) {
327 	unsigned char n;
328 	return li_cton(hex,n) ? (char)n : 0xFF;
329 }
330 
331 
332 int buffer_eq_icase_ssn(const char * const a, const char * const b, const size_t len) {
333     for (size_t i = 0; i < len; ++i) {
334         unsigned int ca = ((unsigned char *)a)[i];
335         unsigned int cb = ((unsigned char *)b)[i];
336         if (ca != cb) {
337             ca |= 0x20;
338             cb |= 0x20;
339             if (ca       !=       cb) return 0;
340             if (ca < 'a' || 'z' < ca) return 0;
341             if (cb < 'a' || 'z' < cb) return 0;
342         }
343     }
344     return 1;
345 }
346 
347 int buffer_eq_icase_ss(const char * const a, const size_t alen, const char * const b, const size_t blen) {
348     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
349     return (alen == blen && buffer_eq_icase_ssn(a, b, blen));
350 }
351 
352 int buffer_eq_icase_slen(const buffer * const b, const char * const s, const size_t slen) {
353     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
354     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
355     return (b->used == slen + 1 && buffer_eq_icase_ssn(b->ptr, s, slen));
356 }
357 
358 int buffer_eq_slen(const buffer * const b, const char * const s, const size_t slen) {
359     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
360     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
361     return (b->used == slen + 1 && 0 == memcmp(b->ptr, s, slen));
362 }
363 
364 
365 /**
366  * check if two buffer contain the same data
367  */
368 
369 int buffer_is_equal(const buffer *a, const buffer *b) {
370 	force_assert(NULL != a && NULL != b);
371 
372 	/* 1 = equal; 0 = not equal */
373 	return (a->used == b->used && 0 == memcmp(a->ptr, b->ptr, a->used));
374 }
375 
376 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len) {
377 	force_assert(NULL != a && NULL != s);
378 	force_assert(b_len + 1 > b_len);
379 
380 	/* 1 = equal; 0 = not equal */
381 	return (a->used == b_len + 1 && 0 == memcmp(a->ptr, s, b_len));
382 }
383 
384 /* buffer_is_equal_caseless_string(b, CONST_STR_LEN("value")) */
385 int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len) {
386 	force_assert(NULL != a && NULL != s);
387 	force_assert(b_len + 1 > b_len);
388 	/* 1 = equal; 0 = not equal */
389 	return buffer_eq_icase_slen(a, s, b_len);
390 }
391 
392 int buffer_is_equal_right_len(const buffer *b1, const buffer *b2, size_t len) {
393 	/* no len -> equal */
394 	if (len == 0) return 1;
395 
396 	/* len > 0, but empty buffers -> not equal */
397 	if (b1->used == 0 || b2->used == 0) return 0;
398 
399 	/* buffers too small -> not equal */
400 	if (b1->used - 1 < len || b2->used - 1 < len) return 0;
401 
402 	return 0 == memcmp(b1->ptr + b1->used - 1 - len, b2->ptr + b2->used - 1 - len, len);
403 }
404 
405 
406 void li_tohex_lc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
407 	force_assert(2 * s_len > s_len);
408 	force_assert(2 * s_len < buf_len);
409 
410 	for (size_t i = 0; i < s_len; ++i) {
411 		buf[2*i]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
412 		buf[2*i+1] = hex_chars_lc[s[i] & 0x0F];
413 	}
414 	buf[2*s_len] = '\0';
415 }
416 
417 void li_tohex_uc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
418 	force_assert(2 * s_len > s_len);
419 	force_assert(2 * s_len < buf_len);
420 
421 	for (size_t i = 0; i < s_len; ++i) {
422 		buf[2*i]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
423 		buf[2*i+1] = hex_chars_uc[s[i] & 0x0F];
424 	}
425 	buf[2*s_len] = '\0';
426 }
427 
428 
429 void buffer_substr_replace (buffer * const restrict b, const size_t offset,
430                             const size_t len, const buffer * const restrict replace)
431 {
432     const size_t blen = buffer_string_length(b);
433     const size_t rlen = buffer_string_length(replace);
434 
435     if (rlen > len) {
436         buffer_string_set_length(b, blen-len+rlen);
437         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
438     }
439 
440     memcpy(b->ptr+offset, replace->ptr, rlen);
441 
442     if (rlen < len) {
443         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
444         buffer_string_set_length(b, blen-len+rlen);
445     }
446 }
447 
448 
449 void buffer_append_string_encoded_hex_lc(buffer * const restrict b, const char * const restrict s, size_t len) {
450     unsigned char * const p =
451       (unsigned char*) buffer_string_prepare_append(b, len*2);
452     buffer_commit(b, len*2); /* fill below */
453     for (size_t i = 0; i < len; ++i) {
454         p[(i<<1)]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
455         p[(i<<1)+1] = hex_chars_lc[(s[i])      & 0x0F];
456     }
457 }
458 
459 void buffer_append_string_encoded_hex_uc(buffer * const restrict b, const char * const restrict s, size_t len) {
460     unsigned char * const p =
461       (unsigned char*) buffer_string_prepare_append(b, len*2);
462     buffer_commit(b, len*2); /* fill below */
463     for (size_t i = 0; i < len; ++i) {
464         p[(i<<1)]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
465         p[(i<<1)+1] = hex_chars_uc[(s[i])      & 0x0F];
466     }
467 }
468 
469 
470 /* everything except: ! ( ) * - . 0-9 A-Z _ a-z */
471 static const char encoded_chars_rel_uri_part[] = {
472 	/*
473 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
474 	*/
475 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
476 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
477 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1,  /*  20 -  2F space " # $ % & ' + , / */
478 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
479 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
480 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
481 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
482 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
483 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
484 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
485 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
486 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
487 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
488 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
489 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
490 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
491 };
492 
493 /* everything except: ! ( ) * - . / 0-9 A-Z _ a-z */
494 static const char encoded_chars_rel_uri[] = {
495 	/*
496 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
497 	*/
498 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
499 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
500 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0,  /*  20 -  2F space " # $ % & ' + , */
501 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
502 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
503 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
504 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
505 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
506 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
507 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
508 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
509 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
510 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
511 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
512 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
513 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
514 };
515 
516 static const char encoded_chars_html[] = {
517 	/*
518 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
519 	*/
520 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
521 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
522 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
523 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
524 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
525 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
526 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
527 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
528 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
529 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
530 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
531 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
532 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
533 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
534 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
535 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
536 };
537 
538 static const char encoded_chars_minimal_xml[] = {
539 	/*
540 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
541 	*/
542 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
543 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
544 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
545 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
546 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
547 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
548 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
549 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
550 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  80 -  8F */
551 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  90 -  9F */
552 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  A0 -  AF */
553 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  B0 -  BF */
554 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  C0 -  CF */
555 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  D0 -  DF */
556 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  E0 -  EF */
557 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  F0 -  FF */
558 };
559 
560 
561 
562 void buffer_append_string_encoded(buffer * const restrict b, const char * const restrict s, size_t s_len, buffer_encoding_t encoding) {
563 	unsigned char *ds, *d;
564 	size_t d_len, ndx;
565 	const char *map = NULL;
566 
567 	if (0 == s_len) return;
568 
569 	force_assert(NULL != s);
570 
571 	switch(encoding) {
572 	case ENCODING_REL_URI:
573 		map = encoded_chars_rel_uri;
574 		break;
575 	case ENCODING_REL_URI_PART:
576 		map = encoded_chars_rel_uri_part;
577 		break;
578 	case ENCODING_HTML:
579 		map = encoded_chars_html;
580 		break;
581 	case ENCODING_MINIMAL_XML:
582 		map = encoded_chars_minimal_xml;
583 		break;
584 	}
585 
586 	force_assert(NULL != map);
587 
588 	/* count to-be-encoded-characters */
589 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
590 		if (map[*ds]) {
591 			switch(encoding) {
592 			case ENCODING_REL_URI:
593 			case ENCODING_REL_URI_PART:
594 				d_len += 3;
595 				break;
596 			case ENCODING_HTML:
597 			case ENCODING_MINIMAL_XML:
598 				d_len += 6;
599 				break;
600 			}
601 		} else {
602 			d_len++;
603 		}
604 	}
605 
606 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
607 	buffer_commit(b, d_len); /* fill below */
608 
609 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
610 		if (map[*ds]) {
611 			switch(encoding) {
612 			case ENCODING_REL_URI:
613 			case ENCODING_REL_URI_PART:
614 				d[d_len++] = '%';
615 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
616 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
617 				break;
618 			case ENCODING_HTML:
619 			case ENCODING_MINIMAL_XML:
620 				d[d_len++] = '&';
621 				d[d_len++] = '#';
622 				d[d_len++] = 'x';
623 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
624 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
625 				d[d_len++] = ';';
626 				break;
627 			}
628 		} else {
629 			d[d_len++] = *ds;
630 		}
631 	}
632 }
633 
634 void buffer_append_string_c_escaped(buffer * const restrict b, const char * const restrict s, size_t s_len) {
635 	unsigned char *ds, *d;
636 	size_t d_len, ndx;
637 
638 	if (0 == s_len) return;
639 
640 	force_assert(NULL != s);
641 
642 	/* count to-be-encoded-characters */
643 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
644 		if ((*ds < 0x20) /* control character */
645 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
646 			switch (*ds) {
647 			case '\t':
648 			case '\r':
649 			case '\n':
650 				d_len += 2;
651 				break;
652 			default:
653 				d_len += 4; /* \xCC */
654 				break;
655 			}
656 		} else {
657 			d_len++;
658 		}
659 	}
660 
661 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
662 	buffer_commit(b, d_len); /* fill below */
663 
664 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
665 		if ((*ds < 0x20) /* control character */
666 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
667 			d[d_len++] = '\\';
668 			switch (*ds) {
669 			case '\t':
670 				d[d_len++] = 't';
671 				break;
672 			case '\r':
673 				d[d_len++] = 'r';
674 				break;
675 			case '\n':
676 				d[d_len++] = 'n';
677 				break;
678 			default:
679 				d[d_len++] = 'x';
680 				d[d_len++] = hex_chars_lc[((*ds) >> 4) & 0x0F];
681 				d[d_len++] = hex_chars_lc[(*ds) & 0x0F];
682 				break;
683 			}
684 		} else {
685 			d[d_len++] = *ds;
686 		}
687 	}
688 }
689 
690 
691 void buffer_copy_string_encoded_cgi_varnames(buffer * const restrict b, const char * const restrict s, size_t s_len, int is_http_header) {
692 	size_t i, j = 0;
693 
694 	force_assert(NULL != b);
695 	force_assert(NULL != s || 0 == s_len);
696 
697 	buffer_string_prepare_copy(b, s_len + 5);
698 
699 	if (is_http_header) {
700 		if (s_len == 12 && buffer_eq_icase_ssn(s, "Content-Type", 12)) {
701 			buffer_copy_string_len(b, CONST_STR_LEN("CONTENT_TYPE"));
702 			return;
703 		}
704 		buffer_copy_string_len(b, CONST_STR_LEN("HTTP_"));
705 		j = 5; /* "HTTP_" */
706 	}
707 
708 	for (i = 0; i < s_len; ++i) {
709 		unsigned char cr = s[i];
710 		if (light_isalpha(cr)) {
711 			/* upper-case */
712 			cr &= ~32;
713 		} else if (!light_isdigit(cr)) {
714 			cr = '_';
715 		}
716 		b->ptr[j++] = cr;
717 	}
718 	b->used = j;
719 	b->ptr[b->used++] = '\0';
720 }
721 
722 /* decodes url-special-chars inplace.
723  * replaces non-printable characters with '_'
724  */
725 
726 static void buffer_urldecode_internal(buffer * const url, const int is_query) {
727 	unsigned char high, low;
728 	char *src;
729 	char *dst;
730 
731 	force_assert(NULL != url);
732 	if (buffer_string_is_empty(url)) return;
733 
734 	force_assert('\0' == url->ptr[url->used-1]);
735 
736 	src = (char*) url->ptr;
737 
738 	if (!is_query) {
739 		while ('\0' != *src && '%' != *src) ++src;
740 	}
741 	else {
742 		for (; '\0' != *src && '%' != *src; ++src) {
743 			if ('+' == *src) *src = ' ';
744 		}
745 	}
746 
747 	if ('\0' == *src) return;
748 
749 	dst = src;
750 
751 	while ('\0' != *src) {
752 		if (is_query && *src == '+') {
753 			*dst = ' ';
754 		} else if (*src == '%') {
755 			*dst = '%';
756 
757 			high = hex2int(*(src + 1));
758 			if (0xFF != high) {
759 				low = hex2int(*(src + 2));
760 				if (0xFF != low) {
761 					high = (high << 4) | low;
762 
763 					/* map control-characters out */
764 					if (high < 32 || high == 127) high = '_';
765 
766 					*dst = high;
767 					src += 2;
768 				}
769 			}
770 		} else {
771 			*dst = *src;
772 		}
773 
774 		dst++;
775 		src++;
776 	}
777 
778 	*dst = '\0';
779 	url->used = (dst - url->ptr) + 1;
780 }
781 
782 void buffer_urldecode_path(buffer *url) {
783 	buffer_urldecode_internal(url, 0);
784 }
785 
786 void buffer_urldecode_query(buffer *url) {
787 	buffer_urldecode_internal(url, 1);
788 }
789 
790 int buffer_is_valid_UTF8(const buffer *b) {
791     /* https://www.w3.org/International/questions/qa-forms-utf-8 */
792     const unsigned char *c = (unsigned char *)b->ptr;
793     while (*c) {
794 
795         /*(note: includes ctrls)*/
796         if (                         c[0] <  0x80 ) { ++c;  continue; }
797 
798         if (         0xc2 <= c[0] && c[0] <= 0xdf
799             &&       0x80 <= c[1] && c[1] <= 0xbf ) { c+=2; continue; }
800 
801         if ( (   (   0xe0 == c[0]
802                   && 0xa0 <= c[1] && c[1] <= 0xbf)
803               || (   0xe1 <= c[0] && c[0] <= 0xef && c[0] != 0xed
804                   && 0x80 <= c[1] && c[1] <= 0xbf)
805               || (   0xed == c[0]
806                   && 0x80 <= c[1] && c[1] <= 0x9f)   )
807             &&       0x80 <= c[2] && c[2] <= 0xbf ) { c+=3; continue; }
808 
809         if ( (   (   0xf0 == c[0]
810                   && 0x90 <= c[1] && c[1] <= 0xbf)
811               || (   0xf1 <= c[0] && c[0] <= 0xf3
812                   && 0x80 <= c[1] && c[1] <= 0xbf)
813               || (   0xf4 == c[0]
814                   && 0x80 <= c[1] && c[1] <= 0x8f)   )
815             &&       0x80 <= c[2] && c[2] <= 0xbf
816             &&       0x80 <= c[3] && c[3] <= 0xbf ) { c+=4; continue; }
817 
818         return 0; /* invalid */
819     }
820     return 1; /* valid */
821 }
822 
823 /* - special case: empty string returns empty string
824  * - on windows or cygwin: replace \ with /
825  * - strip leading spaces
826  * - prepends "/" if not present already
827  * - resolve "/../", "//" and "/./" the usual way:
828  *   the first one removes a preceding component, the other two
829  *   get compressed to "/".
830  * - "/." and "/.." at the end are similar, but always leave a trailing
831  *   "/"
832  *
833  * /blah/..         gets  /
834  * /blah/../foo     gets  /foo
835  * /abc/./xyz       gets  /abc/xyz
836  * /abc//xyz        gets  /abc/xyz
837  *
838  * NOTE: src and dest can point to the same buffer, in which case,
839  *       the operation is performed in-place.
840  */
841 
842 void buffer_path_simplify(buffer *dest, buffer *src)
843 {
844 	/* current character, the one before, and the one before that from input */
845 	char c, pre1, pre2;
846 	char *start, *slash, *walk, *out;
847 
848 	force_assert(NULL != dest && NULL != src);
849 
850 	if (buffer_string_is_empty(src)) {
851 		buffer_copy_string_len(dest, CONST_STR_LEN(""));
852 		return;
853 	}
854 
855 	force_assert('\0' == src->ptr[src->used-1]);
856 
857 #if defined(__WIN32) || defined(__CYGWIN__)
858 	/* cygwin is treating \ and / the same, so we have to that too */
859 	{
860 		char *p;
861 		for (p = src->ptr; *p; p++) {
862 			if (*p == '\\') *p = '/';
863 		}
864 	}
865 #endif
866 
867 	walk  = src->ptr;
868 	start = dest->ptr;
869 	out   = dest->ptr;
870 	slash = dest->ptr;
871 
872 	/* skip leading spaces */
873 	while (*walk == ' ') {
874 		walk++;
875 	}
876 	if (*walk == '.') {
877 		if (walk[1] == '/' || walk[1] == '\0')
878 			++walk;
879 		else if (walk[1] == '.' && (walk[2] == '/' || walk[2] == '\0'))
880 			walk+=2;
881 	}
882 
883 	pre1 = 0;
884 	c = *(walk++);
885 
886 	while (c != '\0') {
887 		/* assert((src != dest || out <= walk) && slash <= out); */
888 		/* the following comments about out and walk are only interesting if
889 		 * src == dest; otherwise the memory areas don't overlap anyway.
890 		 */
891 		pre2 = pre1;
892 		pre1 = c;
893 
894 		/* possibly: out == walk - need to read first */
895 		c    = *walk;
896 		*out = pre1;
897 
898 		out++;
899 		walk++;
900 		/* (out <= walk) still true; also now (slash < out) */
901 
902 		if (c == '/' || c == '\0') {
903 			const size_t toklen = out - slash;
904 			if (toklen == 3 && pre2 == '.' && pre1 == '.' && *slash == '/') {
905 				/* "/../" or ("/.." at end of string) */
906 				out = slash;
907 				/* if there is something before "/..", there is at least one
908 				 * component, which needs to be removed */
909 				if (out > start) {
910 					out--;
911 					while (out > start && *out != '/') out--;
912 				}
913 
914 				/* don't kill trailing '/' at end of path */
915 				if (c == '\0') out++;
916 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
917 			} else if (toklen == 1 || (pre2 == '/' && pre1 == '.')) {
918 				/* "//" or "/./" or (("/" or "/.") at end of string) */
919 				out = slash;
920 				/* don't kill trailing '/' at end of path */
921 				if (c == '\0') out++;
922 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
923 			}
924 
925 			slash = out;
926 		}
927 	}
928 
929 	buffer_string_set_length(dest, out - start);
930 }
931 
932 void buffer_to_lower(buffer * const b) {
933     char * const s = b->ptr;
934     for (uint32_t i = 0; i < b->used; ++i) {
935         char c = s[i];
936         if (c >= 'A' && c <= 'Z') s[i] |= 0x20;
937     }
938 }
939 
940 
941 void buffer_to_upper(buffer * const b) {
942     char * const s = b->ptr;
943     for (uint32_t i = 0; i < b->used; ++i) {
944         char c = s[i];
945         if (c >= 'a' && c <= 'z') s[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