xref: /lighttpd1.4/src/buffer.c (revision 15cdc313)
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 *b, buffer *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 *b, 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 static void buffer_alloc_replace(buffer *b, size_t size) {
89     /*(discard old data so realloc() does not copy)*/
90     if (NULL != b->ptr) {
91         free(b->ptr);
92         b->ptr = NULL;
93     }
94     buffer_realloc(b, size);
95 }
96 
97 char* buffer_string_prepare_copy(buffer *b, size_t size) {
98 	force_assert(NULL != b);
99 
100 	if (size >= b->size) buffer_alloc_replace(b, size);
101 
102 	b->used = 0;
103 	return b->ptr;
104 }
105 
106 char* buffer_string_prepare_append(buffer *b, size_t size) {
107 	force_assert(NULL !=  b);
108 
109 	if (b->used && size < b->size - b->used)
110 		return b->ptr + b->used - 1;
111 
112 	if (buffer_string_is_empty(b)) {
113 		return buffer_string_prepare_copy(b, size);
114 	} else {
115 		/* not empty, b->used already includes a terminating 0 */
116 		size_t req_size = b->used + size;
117 
118 		/* check for overflow: unsigned overflow is defined to wrap around */
119 		force_assert(req_size >= b->used);
120 
121 		buffer_realloc(b, req_size);
122 
123 		return b->ptr + b->used - 1;
124 	}
125 }
126 
127 void buffer_string_set_length(buffer *b, size_t len) {
128 	force_assert(NULL != b);
129 
130 	if (len >= b->size) buffer_realloc(b, len);
131 
132 	b->used = len + 1;
133 	b->ptr[len] = '\0';
134 }
135 
136 void buffer_commit(buffer *b, size_t size)
137 {
138 	force_assert(NULL != b);
139 	force_assert(b->size > 0);
140 
141 	if (0 == b->used) b->used = 1;
142 
143 	if (size > 0) {
144 		/* check for overflow: unsigned overflow is defined to wrap around */
145 		size_t sz = b->used + size;
146 		force_assert(sz > b->used);
147 		force_assert(sz <= b->size);
148 		b->used = sz;
149 	}
150 
151 	b->ptr[b->used - 1] = '\0';
152 }
153 
154 void buffer_copy_string(buffer *b, const char *s) {
155 	buffer_copy_string_len(b, s, NULL != s ? strlen(s) : 0);
156 }
157 
158 void buffer_copy_string_len(buffer *b, const char *s, size_t s_len) {
159 	force_assert(NULL != b);
160 	force_assert(NULL != s || s_len == 0);
161 
162 	if (s_len >= b->size) buffer_string_prepare_copy(b, s_len);
163 
164 	if (0 != s_len) memcpy(b->ptr, s, s_len); /*(s might be NULL)*/
165 	b->ptr[s_len] = '\0';
166 	b->used = s_len + 1;
167 }
168 
169 void buffer_append_string(buffer *b, const char *s) {
170 	buffer_append_string_len(b, s, NULL != s ? strlen(s) : 0);
171 }
172 
173 /**
174  * append a string to the end of the buffer
175  *
176  * the resulting buffer is terminated with a '\0'
177  * s is treated as a un-terminated string (a \0 is handled a normal character)
178  *
179  * @param b a buffer
180  * @param s the string
181  * @param s_len size of the string (without the terminating \0)
182  */
183 
184 void buffer_append_string_len(buffer *b, const char *s, size_t s_len) {
185 	char *target_buf;
186 
187 	force_assert(NULL != b);
188 	force_assert(NULL != s || s_len == 0);
189 
190 	target_buf = buffer_string_prepare_append(b, s_len);
191 	if (0 == b->used) ++b->used; /*(must include '\0' for append below)*/
192 
193 	/*(s might be NULL if 0 == s_len)*/
194 	if (s_len) memcpy(target_buf, s, s_len);
195 	target_buf[s_len] = '\0';
196 	b->used += s_len;
197 }
198 
199 void buffer_append_path_len(buffer *b, const char *a, size_t alen) {
200     size_t blen = buffer_string_length(b);
201     int aslash = (alen && a[0] == '/');
202     buffer_string_prepare_append(b, alen+2); /*(+ '/' and + '\0' if 0 == blen)*/
203     if (blen && b->ptr[blen-1] == '/') {
204         if (aslash) --b->used;
205     }
206     else {
207         if (!b->used) ++b->used;
208         if (!aslash) b->ptr[++b->used - 2] = '/';
209     }
210     memcpy(b->ptr+b->used-1, a, alen);
211     b->ptr[(b->used += alen)-1] = '\0';
212 }
213 
214 void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
215 	char *buf;
216 	unsigned int shift = 0;
217 
218 	{
219 		uintmax_t copy = value;
220 		do {
221 			copy >>= 8;
222 			shift += 8; /* counting bits */
223 		} while (0 != copy);
224 	}
225 
226 	buf = buffer_string_prepare_append(b, shift >> 2); /*nibbles (4 bits)*/
227 	buffer_commit(b, shift >> 2); /* will fill below */
228 
229 	while (shift > 0) {
230 		shift -= 4;
231 		*(buf++) = hex_chars_lc[(value >> shift) & 0x0F];
232 	}
233 }
234 
235 static char* utostr(char * const buf_end, uintmax_t val) {
236 	char *cur = buf_end;
237 	do {
238 		int mod = val % 10;
239 		val /= 10;
240 		/* prepend digit mod */
241 		*(--cur) = (char) ('0' + mod);
242 	} while (0 != val);
243 	return cur;
244 }
245 
246 static char* itostr(char * const buf_end, intmax_t val) {
247 	/* absolute value not defined for INTMAX_MIN, but can take absolute
248 	 * value of any negative number via twos complement cast to unsigned.
249 	 * negative sign is prepended after (now unsigned) value is converted
250 	 * to string */
251 	uintmax_t uval = val >= 0 ? (uintmax_t)val : ((uintmax_t)~val) + 1;
252 	char *cur = utostr(buf_end, uval);
253 	if (val < 0) *(--cur) = '-';
254 
255 	return cur;
256 }
257 
258 void buffer_append_int(buffer *b, intmax_t val) {
259 	char buf[LI_ITOSTRING_LENGTH];
260 	char* const buf_end = buf + sizeof(buf);
261 	char *str;
262 
263 	force_assert(NULL != b);
264 
265 	str = itostr(buf_end, val);
266 	force_assert(buf_end > str && str >= buf);
267 
268 	buffer_append_string_len(b, str, buf_end - str);
269 }
270 
271 void buffer_copy_int(buffer *b, intmax_t val) {
272 	force_assert(NULL != b);
273 
274 	b->used = 0;
275 	buffer_append_int(b, val);
276 }
277 
278 void buffer_append_strftime(buffer *b, const char *format, const struct tm *tm) {
279 	size_t r;
280 	char* buf;
281 	force_assert(NULL != b);
282 	force_assert(NULL != format);
283 	force_assert(NULL != tm);
284 
285 	buf = buffer_string_prepare_append(b, 255);
286 	r = strftime(buf, buffer_string_space(b), format, tm);
287 
288 	/* 0 (in some apis buffer_string_space(b)) signals the string may have
289 	 * been too small; but the format could also just have lead to an empty
290 	 * string
291 	 */
292 	if (0 == r || r >= buffer_string_space(b)) {
293 		/* give it a second try with a larger string */
294 		buf = buffer_string_prepare_append(b, 4095);
295 		r = strftime(buf, buffer_string_space(b), format, tm);
296 	}
297 
298 	if (r >= buffer_string_space(b)) r = 0;
299 
300 	buffer_commit(b, r);
301 }
302 
303 
304 void li_itostrn(char *buf, size_t buf_len, intmax_t val) {
305 	char p_buf[LI_ITOSTRING_LENGTH];
306 	char* const p_buf_end = p_buf + sizeof(p_buf);
307 	char* str = p_buf_end - 1;
308 	*str = '\0';
309 
310 	str = itostr(str, val);
311 	force_assert(p_buf_end > str && str >= p_buf);
312 
313 	force_assert(buf_len >= (size_t) (p_buf_end - str));
314 	memcpy(buf, str, p_buf_end - str);
315 }
316 
317 void li_utostrn(char *buf, size_t buf_len, uintmax_t val) {
318 	char p_buf[LI_ITOSTRING_LENGTH];
319 	char* const p_buf_end = p_buf + sizeof(p_buf);
320 	char* str = p_buf_end - 1;
321 	*str = '\0';
322 
323 	str = utostr(str, val);
324 	force_assert(p_buf_end > str && str >= p_buf);
325 
326 	force_assert(buf_len >= (size_t) (p_buf_end - str));
327 	memcpy(buf, str, p_buf_end - str);
328 }
329 
330 #define li_ntox_lc(n) ((n) <= 9 ? (n) + '0' : (n) + 'a' - 10)
331 
332 char int2hex(char c) {
333 	/*return li_ntox_lc(c & 0xF);*/
334 	return hex_chars_lc[(c & 0x0F)];
335 }
336 
337 /* c (char) and n (nibble) MUST be unsigned integer types */
338 #define li_cton(c,n) \
339   (((n) = (c) - '0') <= 9 || (((n) = ((c)&0xdf) - 'A') <= 5 ? ((n) += 10) : 0))
340 
341 /* converts hex char (0-9, A-Z, a-z) to decimal.
342  * returns 0xFF on invalid input.
343  */
344 char hex2int(unsigned char hex) {
345 	unsigned char n;
346 	return li_cton(hex,n) ? (char)n : 0xFF;
347 }
348 
349 
350 int buffer_eq_icase_ssn(const char * const a, const char * const b, const size_t len) {
351     for (size_t i = 0; i < len; ++i) {
352         unsigned int ca = ((unsigned char *)a)[i];
353         unsigned int cb = ((unsigned char *)b)[i];
354         if (ca != cb) {
355             ca |= 0x20;
356             cb |= 0x20;
357             if (ca       !=       cb) return 0;
358             if (ca < 'a' || 'z' < ca) return 0;
359             if (cb < 'a' || 'z' < cb) return 0;
360         }
361     }
362     return 1;
363 }
364 
365 int buffer_eq_icase_ss(const char * const a, const size_t alen, const char * const b, const size_t blen) {
366     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
367     return (alen == blen && buffer_eq_icase_ssn(a, b, blen));
368 }
369 
370 int buffer_eq_icase_slen(const buffer * const b, const char * const s, const size_t slen) {
371     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
372     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
373     return (b->used == slen + 1 && buffer_eq_icase_ssn(b->ptr, s, slen));
374 }
375 
376 int buffer_eq_slen(const buffer * const b, const char * const s, const size_t slen) {
377     /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
378     /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
379     return (b->used == slen + 1 && 0 == memcmp(b->ptr, s, slen));
380 }
381 
382 
383 /**
384  * check if two buffer contain the same data
385  */
386 
387 int buffer_is_equal(const buffer *a, const buffer *b) {
388 	force_assert(NULL != a && NULL != b);
389 
390 	/* 1 = equal; 0 = not equal */
391 	return (a->used == b->used && 0 == memcmp(a->ptr, b->ptr, a->used));
392 }
393 
394 int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len) {
395 	force_assert(NULL != a && NULL != s);
396 	force_assert(b_len + 1 > b_len);
397 
398 	/* 1 = equal; 0 = not equal */
399 	return (a->used == b_len + 1 && 0 == memcmp(a->ptr, s, b_len));
400 }
401 
402 /* buffer_is_equal_caseless_string(b, CONST_STR_LEN("value")) */
403 int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len) {
404 	force_assert(NULL != a && NULL != s);
405 	force_assert(b_len + 1 > b_len);
406 	/* 1 = equal; 0 = not equal */
407 	return buffer_eq_icase_slen(a, s, b_len);
408 }
409 
410 int buffer_is_equal_right_len(const buffer *b1, const buffer *b2, size_t len) {
411 	/* no len -> equal */
412 	if (len == 0) return 1;
413 
414 	/* len > 0, but empty buffers -> not equal */
415 	if (b1->used == 0 || b2->used == 0) return 0;
416 
417 	/* buffers too small -> not equal */
418 	if (b1->used - 1 < len || b2->used - 1 < len) return 0;
419 
420 	return 0 == memcmp(b1->ptr + b1->used - 1 - len, b2->ptr + b2->used - 1 - len, len);
421 }
422 
423 
424 void li_tohex_lc(char *buf, size_t buf_len, const char *s, size_t s_len) {
425 	force_assert(2 * s_len > s_len);
426 	force_assert(2 * s_len < buf_len);
427 
428 	for (size_t i = 0; i < s_len; ++i) {
429 		buf[2*i]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
430 		buf[2*i+1] = hex_chars_lc[s[i] & 0x0F];
431 	}
432 	buf[2*s_len] = '\0';
433 }
434 
435 void li_tohex_uc(char *buf, size_t buf_len, const char *s, size_t s_len) {
436 	force_assert(2 * s_len > s_len);
437 	force_assert(2 * s_len < buf_len);
438 
439 	for (size_t i = 0; i < s_len; ++i) {
440 		buf[2*i]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
441 		buf[2*i+1] = hex_chars_uc[s[i] & 0x0F];
442 	}
443 	buf[2*s_len] = '\0';
444 }
445 
446 
447 void buffer_substr_replace (buffer * const b, const size_t offset,
448                             const size_t len, const buffer * const replace)
449 {
450     const size_t blen = buffer_string_length(b);
451     const size_t rlen = buffer_string_length(replace);
452 
453     if (rlen > len) {
454         buffer_string_set_length(b, blen-len+rlen);
455         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
456     }
457 
458     memcpy(b->ptr+offset, replace->ptr, rlen);
459 
460     if (rlen < len) {
461         memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
462         buffer_string_set_length(b, blen-len+rlen);
463     }
464 }
465 
466 
467 void buffer_append_string_encoded_hex_lc(buffer *b, const char *s, size_t len) {
468     unsigned char * const p =
469       (unsigned char*) buffer_string_prepare_append(b, len*2);
470     buffer_commit(b, len*2); /* fill below */
471     for (size_t i = 0; i < len; ++i) {
472         p[(i<<1)]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
473         p[(i<<1)+1] = hex_chars_lc[(s[i])      & 0x0F];
474     }
475 }
476 
477 void buffer_append_string_encoded_hex_uc(buffer *b, const char *s, size_t len) {
478     unsigned char * const p =
479       (unsigned char*) buffer_string_prepare_append(b, len*2);
480     buffer_commit(b, len*2); /* fill below */
481     for (size_t i = 0; i < len; ++i) {
482         p[(i<<1)]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
483         p[(i<<1)+1] = hex_chars_uc[(s[i])      & 0x0F];
484     }
485 }
486 
487 
488 /* everything except: ! ( ) * - . 0-9 A-Z _ a-z */
489 static const char encoded_chars_rel_uri_part[] = {
490 	/*
491 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
492 	*/
493 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
494 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
495 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1,  /*  20 -  2F space " # $ % & ' + , / */
496 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
497 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
498 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
499 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
500 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
501 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
502 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
503 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
504 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
505 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
506 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
507 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
508 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
509 };
510 
511 /* everything except: ! ( ) * - . / 0-9 A-Z _ a-z */
512 static const char encoded_chars_rel_uri[] = {
513 	/*
514 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
515 	*/
516 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
517 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
518 	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0,  /*  20 -  2F space " # $ % & ' + , */
519 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
520 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
521 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
522 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
523 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
524 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
525 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
526 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
527 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
528 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
529 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
530 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
531 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
532 };
533 
534 static const char encoded_chars_html[] = {
535 	/*
536 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
537 	*/
538 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
539 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
540 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
541 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
542 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
543 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
544 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
545 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
546 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
547 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
548 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
549 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
550 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
551 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
552 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
553 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
554 };
555 
556 static const char encoded_chars_minimal_xml[] = {
557 	/*
558 	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
559 	*/
560 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
561 	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
562 	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
563 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
564 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
565 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
566 	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
567 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
568 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  80 -  8F */
569 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  90 -  9F */
570 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  A0 -  AF */
571 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  B0 -  BF */
572 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  C0 -  CF */
573 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  D0 -  DF */
574 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  E0 -  EF */
575 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  F0 -  FF */
576 };
577 
578 
579 
580 void buffer_append_string_encoded(buffer *b, const char *s, size_t s_len, buffer_encoding_t encoding) {
581 	unsigned char *ds, *d;
582 	size_t d_len, ndx;
583 	const char *map = NULL;
584 
585 	force_assert(NULL != b);
586 	force_assert(NULL != s || 0 == s_len);
587 
588 	if (0 == s_len) return;
589 
590 	switch(encoding) {
591 	case ENCODING_REL_URI:
592 		map = encoded_chars_rel_uri;
593 		break;
594 	case ENCODING_REL_URI_PART:
595 		map = encoded_chars_rel_uri_part;
596 		break;
597 	case ENCODING_HTML:
598 		map = encoded_chars_html;
599 		break;
600 	case ENCODING_MINIMAL_XML:
601 		map = encoded_chars_minimal_xml;
602 		break;
603 	}
604 
605 	force_assert(NULL != map);
606 
607 	/* count to-be-encoded-characters */
608 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
609 		if (map[*ds]) {
610 			switch(encoding) {
611 			case ENCODING_REL_URI:
612 			case ENCODING_REL_URI_PART:
613 				d_len += 3;
614 				break;
615 			case ENCODING_HTML:
616 			case ENCODING_MINIMAL_XML:
617 				d_len += 6;
618 				break;
619 			}
620 		} else {
621 			d_len++;
622 		}
623 	}
624 
625 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
626 	buffer_commit(b, d_len); /* fill below */
627 
628 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
629 		if (map[*ds]) {
630 			switch(encoding) {
631 			case ENCODING_REL_URI:
632 			case ENCODING_REL_URI_PART:
633 				d[d_len++] = '%';
634 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
635 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
636 				break;
637 			case ENCODING_HTML:
638 			case ENCODING_MINIMAL_XML:
639 				d[d_len++] = '&';
640 				d[d_len++] = '#';
641 				d[d_len++] = 'x';
642 				d[d_len++] = hex_chars_uc[((*ds) >> 4) & 0x0F];
643 				d[d_len++] = hex_chars_uc[(*ds) & 0x0F];
644 				d[d_len++] = ';';
645 				break;
646 			}
647 		} else {
648 			d[d_len++] = *ds;
649 		}
650 	}
651 }
652 
653 void buffer_append_string_c_escaped(buffer *b, const char *s, size_t s_len) {
654 	unsigned char *ds, *d;
655 	size_t d_len, ndx;
656 
657 	force_assert(NULL != b);
658 	force_assert(NULL != s || 0 == s_len);
659 
660 	if (0 == s_len) return;
661 
662 	/* count to-be-encoded-characters */
663 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
664 		if ((*ds < 0x20) /* control character */
665 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
666 			switch (*ds) {
667 			case '\t':
668 			case '\r':
669 			case '\n':
670 				d_len += 2;
671 				break;
672 			default:
673 				d_len += 4; /* \xCC */
674 				break;
675 			}
676 		} else {
677 			d_len++;
678 		}
679 	}
680 
681 	d = (unsigned char*) buffer_string_prepare_append(b, d_len);
682 	buffer_commit(b, d_len); /* fill below */
683 
684 	for (ds = (unsigned char *)s, d_len = 0, ndx = 0; ndx < s_len; ds++, ndx++) {
685 		if ((*ds < 0x20) /* control character */
686 				|| (*ds >= 0x7f)) { /* DEL + non-ASCII characters */
687 			d[d_len++] = '\\';
688 			switch (*ds) {
689 			case '\t':
690 				d[d_len++] = 't';
691 				break;
692 			case '\r':
693 				d[d_len++] = 'r';
694 				break;
695 			case '\n':
696 				d[d_len++] = 'n';
697 				break;
698 			default:
699 				d[d_len++] = 'x';
700 				d[d_len++] = hex_chars_lc[((*ds) >> 4) & 0x0F];
701 				d[d_len++] = hex_chars_lc[(*ds) & 0x0F];
702 				break;
703 			}
704 		} else {
705 			d[d_len++] = *ds;
706 		}
707 	}
708 }
709 
710 
711 void buffer_copy_string_encoded_cgi_varnames(buffer *b, const char *s, size_t s_len, int is_http_header) {
712 	size_t i, j = 0;
713 
714 	force_assert(NULL != b);
715 	force_assert(NULL != s || 0 == s_len);
716 
717 	buffer_string_prepare_copy(b, s_len + 5);
718 
719 	if (is_http_header) {
720 		if (s_len == 12 && buffer_eq_icase_ssn(s, "Content-Type", 12)) {
721 			buffer_copy_string_len(b, CONST_STR_LEN("CONTENT_TYPE"));
722 			return;
723 		}
724 		buffer_copy_string_len(b, CONST_STR_LEN("HTTP_"));
725 		j = 5; /* "HTTP_" */
726 	}
727 
728 	for (i = 0; i < s_len; ++i) {
729 		unsigned char cr = s[i];
730 		if (light_isalpha(cr)) {
731 			/* upper-case */
732 			cr &= ~32;
733 		} else if (!light_isdigit(cr)) {
734 			cr = '_';
735 		}
736 		b->ptr[j++] = cr;
737 	}
738 	b->used = j;
739 	b->ptr[b->used++] = '\0';
740 }
741 
742 /* decodes url-special-chars inplace.
743  * replaces non-printable characters with '_'
744  */
745 
746 static void buffer_urldecode_internal(buffer *url, int is_query) {
747 	unsigned char high, low;
748 	char *src;
749 	char *dst;
750 
751 	force_assert(NULL != url);
752 	if (buffer_string_is_empty(url)) return;
753 
754 	force_assert('\0' == url->ptr[url->used-1]);
755 
756 	src = (char*) url->ptr;
757 
758 	while ('\0' != *src) {
759 		if ('%' == *src) break;
760 		if (is_query && '+' == *src) *src = ' ';
761 		src++;
762 	}
763 	dst = src;
764 
765 	while ('\0' != *src) {
766 		if (is_query && *src == '+') {
767 			*dst = ' ';
768 		} else if (*src == '%') {
769 			*dst = '%';
770 
771 			high = hex2int(*(src + 1));
772 			if (0xFF != high) {
773 				low = hex2int(*(src + 2));
774 				if (0xFF != low) {
775 					high = (high << 4) | low;
776 
777 					/* map control-characters out */
778 					if (high < 32 || high == 127) high = '_';
779 
780 					*dst = high;
781 					src += 2;
782 				}
783 			}
784 		} else {
785 			*dst = *src;
786 		}
787 
788 		dst++;
789 		src++;
790 	}
791 
792 	*dst = '\0';
793 	url->used = (dst - url->ptr) + 1;
794 }
795 
796 void buffer_urldecode_path(buffer *url) {
797 	buffer_urldecode_internal(url, 0);
798 }
799 
800 void buffer_urldecode_query(buffer *url) {
801 	buffer_urldecode_internal(url, 1);
802 }
803 
804 int buffer_is_valid_UTF8(const buffer *b) {
805     /* https://www.w3.org/International/questions/qa-forms-utf-8 */
806     const unsigned char *c = (unsigned char *)b->ptr;
807     while (*c) {
808 
809         /*(note: includes ctrls)*/
810         if (                         c[0] <  0x80 ) { ++c;  continue; }
811 
812         if (         0xc2 <= c[0] && c[0] <= 0xdf
813             &&       0x80 <= c[1] && c[1] <= 0xbf ) { c+=2; continue; }
814 
815         if ( (   (   0xe0 == c[0]
816                   && 0xa0 <= c[1] && c[1] <= 0xbf)
817               || (   0xe1 <= c[0] && c[0] <= 0xef && c[0] != 0xed
818                   && 0x80 <= c[1] && c[1] <= 0xbf)
819               || (   0xed == c[0]
820                   && 0x80 <= c[1] && c[1] <= 0x9f)   )
821             &&       0x80 <= c[2] && c[2] <= 0xbf ) { c+=3; continue; }
822 
823         if ( (   (   0xf0 == c[0]
824                   && 0x90 <= c[1] && c[1] <= 0xbf)
825               || (   0xf1 <= c[0] && c[0] <= 0xf3
826                   && 0x80 <= c[1] && c[1] <= 0xbf)
827               || (   0xf4 == c[0]
828                   && 0x80 <= c[1] && c[1] <= 0x8f)   )
829             &&       0x80 <= c[2] && c[2] <= 0xbf
830             &&       0x80 <= c[3] && c[3] <= 0xbf ) { c+=4; continue; }
831 
832         return 0; /* invalid */
833     }
834     return 1; /* valid */
835 }
836 
837 /* - special case: empty string returns empty string
838  * - on windows or cygwin: replace \ with /
839  * - strip leading spaces
840  * - prepends "/" if not present already
841  * - resolve "/../", "//" and "/./" the usual way:
842  *   the first one removes a preceding component, the other two
843  *   get compressed to "/".
844  * - "/." and "/.." at the end are similar, but always leave a trailing
845  *   "/"
846  *
847  * /blah/..         gets  /
848  * /blah/../foo     gets  /foo
849  * /abc/./xyz       gets  /abc/xyz
850  * /abc//xyz        gets  /abc/xyz
851  *
852  * NOTE: src and dest can point to the same buffer, in which case,
853  *       the operation is performed in-place.
854  */
855 
856 void buffer_path_simplify(buffer *dest, buffer *src)
857 {
858 	/* current character, the one before, and the one before that from input */
859 	char c, pre1, pre2;
860 	char *start, *slash, *walk, *out;
861 
862 	force_assert(NULL != dest && NULL != src);
863 
864 	if (buffer_string_is_empty(src)) {
865 		buffer_copy_string_len(dest, CONST_STR_LEN(""));
866 		return;
867 	}
868 
869 	force_assert('\0' == src->ptr[src->used-1]);
870 
871 #if defined(__WIN32) || defined(__CYGWIN__)
872 	/* cygwin is treating \ and / the same, so we have to that too */
873 	{
874 		char *p;
875 		for (p = src->ptr; *p; p++) {
876 			if (*p == '\\') *p = '/';
877 		}
878 	}
879 #endif
880 
881 	walk  = src->ptr;
882 	start = dest->ptr;
883 	out   = dest->ptr;
884 	slash = dest->ptr;
885 
886 	/* skip leading spaces */
887 	while (*walk == ' ') {
888 		walk++;
889 	}
890 	if (*walk == '.') {
891 		if (walk[1] == '/' || walk[1] == '\0')
892 			++walk;
893 		else if (walk[1] == '.' && (walk[2] == '/' || walk[2] == '\0'))
894 			walk+=2;
895 	}
896 
897 	pre1 = 0;
898 	c = *(walk++);
899 
900 	while (c != '\0') {
901 		/* assert((src != dest || out <= walk) && slash <= out); */
902 		/* the following comments about out and walk are only interesting if
903 		 * src == dest; otherwise the memory areas don't overlap anyway.
904 		 */
905 		pre2 = pre1;
906 		pre1 = c;
907 
908 		/* possibly: out == walk - need to read first */
909 		c    = *walk;
910 		*out = pre1;
911 
912 		out++;
913 		walk++;
914 		/* (out <= walk) still true; also now (slash < out) */
915 
916 		if (c == '/' || c == '\0') {
917 			const size_t toklen = out - slash;
918 			if (toklen == 3 && pre2 == '.' && pre1 == '.' && *slash == '/') {
919 				/* "/../" or ("/.." at end of string) */
920 				out = slash;
921 				/* if there is something before "/..", there is at least one
922 				 * component, which needs to be removed */
923 				if (out > start) {
924 					out--;
925 					while (out > start && *out != '/') out--;
926 				}
927 
928 				/* don't kill trailing '/' at end of path */
929 				if (c == '\0') out++;
930 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
931 			} else if (toklen == 1 || (pre2 == '/' && pre1 == '.')) {
932 				/* "//" or "/./" or (("/" or "/.") at end of string) */
933 				out = slash;
934 				/* don't kill trailing '/' at end of path */
935 				if (c == '\0') out++;
936 				/* slash < out before, so out_new <= slash + 1 <= out_before <= walk */
937 			}
938 
939 			slash = out;
940 		}
941 	}
942 
943 	buffer_string_set_length(dest, out - start);
944 }
945 
946 void buffer_to_lower(buffer *b) {
947 	size_t i;
948 
949 	for (i = 0; i < b->used; ++i) {
950 		char c = b->ptr[i];
951 		if (c >= 'A' && c <= 'Z') b->ptr[i] |= 0x20;
952 	}
953 }
954 
955 
956 void buffer_to_upper(buffer *b) {
957 	size_t i;
958 
959 	for (i = 0; i < b->used; ++i) {
960 		char c = b->ptr[i];
961 		if (c >= 'a' && c <= 'z') b->ptr[i] &= ~0x20;
962 	}
963 }
964 
965 
966 #include <stdio.h>
967 
968 #ifdef HAVE_LIBUNWIND
969 # define UNW_LOCAL_ONLY
970 # include <libunwind.h>
971 
972 static void print_backtrace(FILE *file) {
973 	unw_cursor_t cursor;
974 	unw_context_t context;
975 	int ret;
976 	unsigned int frame = 0;
977 
978 	if (0 != (ret = unw_getcontext(&context))) goto error;
979 	if (0 != (ret = unw_init_local(&cursor, &context))) goto error;
980 
981 	fprintf(file, "Backtrace:\n");
982 
983 	while (0 < (ret = unw_step(&cursor))) {
984 		unw_word_t proc_ip = 0;
985 		unw_proc_info_t procinfo;
986 		char procname[256];
987 		unw_word_t proc_offset = 0;
988 
989 		if (0 != (ret = unw_get_reg(&cursor, UNW_REG_IP, &proc_ip))) goto error;
990 
991 		if (0 == proc_ip) {
992 			/* without an IP the other functions are useless; unw_get_proc_name would return UNW_EUNSPEC */
993 			++frame;
994 			fprintf(file, "%u: (nil)\n", frame);
995 			continue;
996 		}
997 
998 		if (0 != (ret = unw_get_proc_info(&cursor, &procinfo))) goto error;
999 
1000 		if (0 != (ret = unw_get_proc_name(&cursor, procname, sizeof(procname), &proc_offset))) {
1001 			switch (-ret) {
1002 			case UNW_ENOMEM:
1003 				memset(procname + sizeof(procname) - 4, '.', 3);
1004 				procname[sizeof(procname) - 1] = '\0';
1005 				break;
1006 			case UNW_ENOINFO:
1007 				procname[0] = '?';
1008 				procname[1] = '\0';
1009 				proc_offset = 0;
1010 				break;
1011 			default:
1012 				snprintf(procname, sizeof(procname), "?? (unw_get_proc_name error %d)", -ret);
1013 				break;
1014 			}
1015 		}
1016 
1017 		++frame;
1018 		fprintf(file, "%u: %s (+0x%x) [%p]\n",
1019 			frame,
1020 			procname,
1021 			(unsigned int) proc_offset,
1022 			(void*)(uintptr_t)proc_ip);
1023 	}
1024 
1025 	if (0 != ret) goto error;
1026 
1027 	return;
1028 
1029 error:
1030 	fprintf(file, "Error while generating backtrace: unwind error %i\n", (int) -ret);
1031 }
1032 #else
1033 static void print_backtrace(FILE *file) {
1034 	UNUSED(file);
1035 }
1036 #endif
1037 
1038 void log_failed_assert(const char *filename, unsigned int line, const char *msg) {
1039 	/* can't use buffer here; could lead to recursive assertions */
1040 	fprintf(stderr, "%s.%u: %s\n", filename, line, msg);
1041 	print_backtrace(stderr);
1042 	fflush(stderr);
1043 	abort();
1044 }
1045