1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2 /*
3 * stdlib function definitions for NOLIBC
4 * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
5 */
6
7 #ifndef _NOLIBC_STDLIB_H
8 #define _NOLIBC_STDLIB_H
9
10 #include "std.h"
11 #include "arch.h"
12 #include "types.h"
13 #include "sys.h"
14 #include "string.h"
15 #include <linux/auxvec.h>
16
17 struct nolibc_heap {
18 size_t len;
19 char user_p[] __attribute__((__aligned__));
20 };
21
22 /* Buffer used to store int-to-ASCII conversions. Will only be implemented if
23 * any of the related functions is implemented. The area is large enough to
24 * store "18446744073709551615" or "-9223372036854775808" and the final zero.
25 */
26 static __attribute__((unused)) char itoa_buffer[21];
27
28 /*
29 * As much as possible, please keep functions alphabetically sorted.
30 */
31
32 /* must be exported, as it's used by libgcc for various divide functions */
33 __attribute__((weak,unused,noreturn,section(".text.nolibc_abort")))
abort(void)34 void abort(void)
35 {
36 sys_kill(sys_getpid(), SIGABRT);
37 for (;;);
38 }
39
40 static __attribute__((unused))
atol(const char * s)41 long atol(const char *s)
42 {
43 unsigned long ret = 0;
44 unsigned long d;
45 int neg = 0;
46
47 if (*s == '-') {
48 neg = 1;
49 s++;
50 }
51
52 while (1) {
53 d = (*s++) - '0';
54 if (d > 9)
55 break;
56 ret *= 10;
57 ret += d;
58 }
59
60 return neg ? -ret : ret;
61 }
62
63 static __attribute__((unused))
atoi(const char * s)64 int atoi(const char *s)
65 {
66 return atol(s);
67 }
68
69 static __attribute__((unused))
free(void * ptr)70 void free(void *ptr)
71 {
72 struct nolibc_heap *heap;
73
74 if (!ptr)
75 return;
76
77 heap = container_of(ptr, struct nolibc_heap, user_p);
78 munmap(heap, heap->len);
79 }
80
81 /* getenv() tries to find the environment variable named <name> in the
82 * environment array pointed to by global variable "environ" which must be
83 * declared as a char **, and must be terminated by a NULL (it is recommended
84 * to set this variable to the "envp" argument of main()). If the requested
85 * environment variable exists its value is returned otherwise NULL is
86 * returned.
87 */
88 static __attribute__((unused))
getenv(const char * name)89 char *getenv(const char *name)
90 {
91 int idx, i;
92
93 if (environ) {
94 for (idx = 0; environ[idx]; idx++) {
95 for (i = 0; name[i] && name[i] == environ[idx][i];)
96 i++;
97 if (!name[i] && environ[idx][i] == '=')
98 return &environ[idx][i+1];
99 }
100 }
101 return NULL;
102 }
103
104 static __attribute__((unused))
getauxval(unsigned long type)105 unsigned long getauxval(unsigned long type)
106 {
107 const unsigned long *auxv = _auxv;
108 unsigned long ret;
109
110 if (!auxv)
111 return 0;
112
113 while (1) {
114 if (!auxv[0] && !auxv[1]) {
115 ret = 0;
116 break;
117 }
118
119 if (auxv[0] == type) {
120 ret = auxv[1];
121 break;
122 }
123
124 auxv += 2;
125 }
126
127 return ret;
128 }
129
130 static __attribute__((unused))
malloc(size_t len)131 void *malloc(size_t len)
132 {
133 struct nolibc_heap *heap;
134
135 /* Always allocate memory with size multiple of 4096. */
136 len = sizeof(*heap) + len;
137 len = (len + 4095UL) & -4096UL;
138 heap = mmap(NULL, len, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE,
139 -1, 0);
140 if (__builtin_expect(heap == MAP_FAILED, 0))
141 return NULL;
142
143 heap->len = len;
144 return heap->user_p;
145 }
146
147 static __attribute__((unused))
calloc(size_t size,size_t nmemb)148 void *calloc(size_t size, size_t nmemb)
149 {
150 size_t x = size * nmemb;
151
152 if (__builtin_expect(size && ((x / size) != nmemb), 0)) {
153 SET_ERRNO(ENOMEM);
154 return NULL;
155 }
156
157 /*
158 * No need to zero the heap, the MAP_ANONYMOUS in malloc()
159 * already does it.
160 */
161 return malloc(x);
162 }
163
164 static __attribute__((unused))
realloc(void * old_ptr,size_t new_size)165 void *realloc(void *old_ptr, size_t new_size)
166 {
167 struct nolibc_heap *heap;
168 size_t user_p_len;
169 void *ret;
170
171 if (!old_ptr)
172 return malloc(new_size);
173
174 heap = container_of(old_ptr, struct nolibc_heap, user_p);
175 user_p_len = heap->len - sizeof(*heap);
176 /*
177 * Don't realloc() if @user_p_len >= @new_size, this block of
178 * memory is still enough to handle the @new_size. Just return
179 * the same pointer.
180 */
181 if (user_p_len >= new_size)
182 return old_ptr;
183
184 ret = malloc(new_size);
185 if (__builtin_expect(!ret, 0))
186 return NULL;
187
188 memcpy(ret, heap->user_p, heap->len);
189 munmap(heap, heap->len);
190 return ret;
191 }
192
193 /* Converts the unsigned long integer <in> to its hex representation into
194 * buffer <buffer>, which must be long enough to store the number and the
195 * trailing zero (17 bytes for "ffffffffffffffff" or 9 for "ffffffff"). The
196 * buffer is filled from the first byte, and the number of characters emitted
197 * (not counting the trailing zero) is returned. The function is constructed
198 * in a way to optimize the code size and avoid any divide that could add a
199 * dependency on large external functions.
200 */
201 static __attribute__((unused))
utoh_r(unsigned long in,char * buffer)202 int utoh_r(unsigned long in, char *buffer)
203 {
204 signed char pos = (~0UL > 0xfffffffful) ? 60 : 28;
205 int digits = 0;
206 int dig;
207
208 do {
209 dig = in >> pos;
210 in -= (uint64_t)dig << pos;
211 pos -= 4;
212 if (dig || digits || pos < 0) {
213 if (dig > 9)
214 dig += 'a' - '0' - 10;
215 buffer[digits++] = '0' + dig;
216 }
217 } while (pos >= 0);
218
219 buffer[digits] = 0;
220 return digits;
221 }
222
223 /* converts unsigned long <in> to an hex string using the static itoa_buffer
224 * and returns the pointer to that string.
225 */
226 static __inline__ __attribute__((unused))
utoh(unsigned long in)227 char *utoh(unsigned long in)
228 {
229 utoh_r(in, itoa_buffer);
230 return itoa_buffer;
231 }
232
233 /* Converts the unsigned long integer <in> to its string representation into
234 * buffer <buffer>, which must be long enough to store the number and the
235 * trailing zero (21 bytes for 18446744073709551615 in 64-bit, 11 for
236 * 4294967295 in 32-bit). The buffer is filled from the first byte, and the
237 * number of characters emitted (not counting the trailing zero) is returned.
238 * The function is constructed in a way to optimize the code size and avoid
239 * any divide that could add a dependency on large external functions.
240 */
241 static __attribute__((unused))
utoa_r(unsigned long in,char * buffer)242 int utoa_r(unsigned long in, char *buffer)
243 {
244 unsigned long lim;
245 int digits = 0;
246 int pos = (~0UL > 0xfffffffful) ? 19 : 9;
247 int dig;
248
249 do {
250 for (dig = 0, lim = 1; dig < pos; dig++)
251 lim *= 10;
252
253 if (digits || in >= lim || !pos) {
254 for (dig = 0; in >= lim; dig++)
255 in -= lim;
256 buffer[digits++] = '0' + dig;
257 }
258 } while (pos--);
259
260 buffer[digits] = 0;
261 return digits;
262 }
263
264 /* Converts the signed long integer <in> to its string representation into
265 * buffer <buffer>, which must be long enough to store the number and the
266 * trailing zero (21 bytes for -9223372036854775808 in 64-bit, 12 for
267 * -2147483648 in 32-bit). The buffer is filled from the first byte, and the
268 * number of characters emitted (not counting the trailing zero) is returned.
269 */
270 static __attribute__((unused))
itoa_r(long in,char * buffer)271 int itoa_r(long in, char *buffer)
272 {
273 char *ptr = buffer;
274 int len = 0;
275
276 if (in < 0) {
277 in = -in;
278 *(ptr++) = '-';
279 len++;
280 }
281 len += utoa_r(in, ptr);
282 return len;
283 }
284
285 /* for historical compatibility, same as above but returns the pointer to the
286 * buffer.
287 */
288 static __inline__ __attribute__((unused))
ltoa_r(long in,char * buffer)289 char *ltoa_r(long in, char *buffer)
290 {
291 itoa_r(in, buffer);
292 return buffer;
293 }
294
295 /* converts long integer <in> to a string using the static itoa_buffer and
296 * returns the pointer to that string.
297 */
298 static __inline__ __attribute__((unused))
itoa(long in)299 char *itoa(long in)
300 {
301 itoa_r(in, itoa_buffer);
302 return itoa_buffer;
303 }
304
305 /* converts long integer <in> to a string using the static itoa_buffer and
306 * returns the pointer to that string. Same as above, for compatibility.
307 */
308 static __inline__ __attribute__((unused))
ltoa(long in)309 char *ltoa(long in)
310 {
311 itoa_r(in, itoa_buffer);
312 return itoa_buffer;
313 }
314
315 /* converts unsigned long integer <in> to a string using the static itoa_buffer
316 * and returns the pointer to that string.
317 */
318 static __inline__ __attribute__((unused))
utoa(unsigned long in)319 char *utoa(unsigned long in)
320 {
321 utoa_r(in, itoa_buffer);
322 return itoa_buffer;
323 }
324
325 /* Converts the unsigned 64-bit integer <in> to its hex representation into
326 * buffer <buffer>, which must be long enough to store the number and the
327 * trailing zero (17 bytes for "ffffffffffffffff"). The buffer is filled from
328 * the first byte, and the number of characters emitted (not counting the
329 * trailing zero) is returned. The function is constructed in a way to optimize
330 * the code size and avoid any divide that could add a dependency on large
331 * external functions.
332 */
333 static __attribute__((unused))
u64toh_r(uint64_t in,char * buffer)334 int u64toh_r(uint64_t in, char *buffer)
335 {
336 signed char pos = 60;
337 int digits = 0;
338 int dig;
339
340 do {
341 if (sizeof(long) >= 8) {
342 dig = (in >> pos) & 0xF;
343 } else {
344 /* 32-bit platforms: avoid a 64-bit shift */
345 uint32_t d = (pos >= 32) ? (in >> 32) : in;
346 dig = (d >> (pos & 31)) & 0xF;
347 }
348 if (dig > 9)
349 dig += 'a' - '0' - 10;
350 pos -= 4;
351 if (dig || digits || pos < 0)
352 buffer[digits++] = '0' + dig;
353 } while (pos >= 0);
354
355 buffer[digits] = 0;
356 return digits;
357 }
358
359 /* converts uint64_t <in> to an hex string using the static itoa_buffer and
360 * returns the pointer to that string.
361 */
362 static __inline__ __attribute__((unused))
u64toh(uint64_t in)363 char *u64toh(uint64_t in)
364 {
365 u64toh_r(in, itoa_buffer);
366 return itoa_buffer;
367 }
368
369 /* Converts the unsigned 64-bit integer <in> to its string representation into
370 * buffer <buffer>, which must be long enough to store the number and the
371 * trailing zero (21 bytes for 18446744073709551615). The buffer is filled from
372 * the first byte, and the number of characters emitted (not counting the
373 * trailing zero) is returned. The function is constructed in a way to optimize
374 * the code size and avoid any divide that could add a dependency on large
375 * external functions.
376 */
377 static __attribute__((unused))
u64toa_r(uint64_t in,char * buffer)378 int u64toa_r(uint64_t in, char *buffer)
379 {
380 unsigned long long lim;
381 int digits = 0;
382 int pos = 19; /* start with the highest possible digit */
383 int dig;
384
385 do {
386 for (dig = 0, lim = 1; dig < pos; dig++)
387 lim *= 10;
388
389 if (digits || in >= lim || !pos) {
390 for (dig = 0; in >= lim; dig++)
391 in -= lim;
392 buffer[digits++] = '0' + dig;
393 }
394 } while (pos--);
395
396 buffer[digits] = 0;
397 return digits;
398 }
399
400 /* Converts the signed 64-bit integer <in> to its string representation into
401 * buffer <buffer>, which must be long enough to store the number and the
402 * trailing zero (21 bytes for -9223372036854775808). The buffer is filled from
403 * the first byte, and the number of characters emitted (not counting the
404 * trailing zero) is returned.
405 */
406 static __attribute__((unused))
i64toa_r(int64_t in,char * buffer)407 int i64toa_r(int64_t in, char *buffer)
408 {
409 char *ptr = buffer;
410 int len = 0;
411
412 if (in < 0) {
413 in = -in;
414 *(ptr++) = '-';
415 len++;
416 }
417 len += u64toa_r(in, ptr);
418 return len;
419 }
420
421 /* converts int64_t <in> to a string using the static itoa_buffer and returns
422 * the pointer to that string.
423 */
424 static __inline__ __attribute__((unused))
i64toa(int64_t in)425 char *i64toa(int64_t in)
426 {
427 i64toa_r(in, itoa_buffer);
428 return itoa_buffer;
429 }
430
431 /* converts uint64_t <in> to a string using the static itoa_buffer and returns
432 * the pointer to that string.
433 */
434 static __inline__ __attribute__((unused))
u64toa(uint64_t in)435 char *u64toa(uint64_t in)
436 {
437 u64toa_r(in, itoa_buffer);
438 return itoa_buffer;
439 }
440
441 /* make sure to include all global symbols */
442 #include "nolibc.h"
443
444 #endif /* _NOLIBC_STDLIB_H */
445
