summaryrefslogtreecommitdiffstats
path: root/include/osmocom/core/utils.h
blob: 8585a6a9a0ba4315e11fe38cd131c20737a67551 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
#pragma once

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>

#include <osmocom/core/backtrace.h>
#include <osmocom/core/talloc.h>
#include <osmocom/core/panic.h>
#include <osmocom/core/defs.h>

/*! \defgroup utils General-purpose utility functions
 *  @{
 * \file utils.h */

/*! Determine number of elements in an array of static size */
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
/*! Return the maximum of two specified values */
#define OSMO_MAX(a, b) ((a) >= (b) ? (a) : (b))
/*! Return the minimum of two specified values */
#define OSMO_MIN(a, b) ((a) >= (b) ? (b) : (a))
/*! Stringify the name of a macro x, e.g. an FSM event name.
 * Note: if nested within another preprocessor macro, this will
 * stringify the value of x instead of its name. */
#define OSMO_STRINGIFY(x) #x
/*! Stringify the value of a macro x, e.g. a port number. */
#define OSMO_STRINGIFY_VAL(x) OSMO_STRINGIFY(x)
/*! Make a value_string entry from an enum value name */
#define OSMO_VALUE_STRING(x) { x, #x }
/*! Number of bytes necessary to store given BITS */
#define OSMO_BYTES_FOR_BITS(BITS) ((BITS + 8 - 1) / 8)

/*! Copy a C-string into a sized buffer using sizeof to detect buffer's size */
#define OSMO_STRLCPY_ARRAY(array, src) osmo_strlcpy(array, src, sizeof(array))

/*! A mapping between human-readable string and numeric value */
struct value_string {
	unsigned int value;	/*!< numeric value */
	const char *str;	/*!< human-readable string */
};

const char *get_value_string(const struct value_string *vs, uint32_t val);
const char *get_value_string_or_null(const struct value_string *vs,
				     uint32_t val);

int get_string_value(const struct value_string *vs, const char *str);

char osmo_bcd2char(uint8_t bcd);
/* only works for numbers in ASCII */
uint8_t osmo_char2bcd(char c);

int osmo_bcd2str(char *dst, size_t dst_size, const uint8_t *bcd, int start_nibble, int end_nibble, bool allow_hex);

int osmo_hexparse(const char *str, uint8_t *b, int max_len);

char *osmo_ubit_dump_buf(char *buf, size_t buf_len, const uint8_t *bits, unsigned int len);
char *osmo_ubit_dump(const uint8_t *bits, unsigned int len);
char *osmo_hexdump(const unsigned char *buf, int len);
char *osmo_hexdump_c(const void *ctx, const unsigned char *buf, int len);
char *osmo_hexdump_nospc(const unsigned char *buf, int len);
char *osmo_hexdump_nospc_c(const void *ctx, const unsigned char *buf, int len);
const char *osmo_hexdump_buf(char *out_buf, size_t out_buf_size, const unsigned char *buf, int len, const char *delim,
			     bool delim_after_last);

char *osmo_osmo_hexdump_nospc(const unsigned char *buf, int len) __attribute__((__deprecated__));

#define osmo_static_assert(exp, name) typedef int dummy##name [(exp) ? 1 : -1] __attribute__((__unused__));

void osmo_str2lower(char *out, const char *in)
	OSMO_DEPRECATED("Use osmo_str_tolower() or osmo_str_tolower_buf() instead,"
			" to properly check target memory bounds");
void osmo_str2upper(char *out, const char *in)
	OSMO_DEPRECATED("Use osmo_str_toupper() or osmo_str_toupper_buf() instead,"
			" to properly check target memory bounds");

size_t osmo_str_tolower_buf(char *dest, size_t dest_len, const char *src);
const char *osmo_str_tolower(const char *src);
char *osmo_str_tolower_c(const void *ctx, const char *src);

size_t osmo_str_toupper_buf(char *dest, size_t dest_len, const char *src);
const char *osmo_str_toupper(const char *src);
char *osmo_str_toupper_c(const void *ctx, const char *src);

#define OSMO_SNPRINTF_RET(ret, rem, offset, len)		\
do {								\
	len += ret;						\
	if (ret > rem)						\
		ret = rem;					\
	offset += ret;						\
	rem -= ret;						\
} while (0)

/*! Helper macro to terminate when an assertion fails
 *  \param[in] exp Predicate to verify
 *  This function will generate a backtrace and terminate the program if
 *  the predicate evaluates to false (0).
 */
#define OSMO_ASSERT(exp)    \
	do if (!(exp)) { \
		osmo_panic("Assert failed %s %s:%d\n", #exp, __FILE__, __LINE__); \
	} while(0)

/*! duplicate a string using talloc and release its prior content (if any)
 * \param[in] ctx Talloc context to use for allocation
 * \param[out] dst pointer to string, will be updated with ptr to new string
 * \param[in] newstr String that will be copied to newly allocated string */
static inline void osmo_talloc_replace_string(void *ctx, char **dst, const char *newstr)
{
	if (*dst)
		talloc_free(*dst);
	*dst = talloc_strdup(ctx, newstr);
}

/*! Append to a string and re-/allocate if necessary.
 * \param[in] ctx  Talloc context to use for initial allocation.
 * \param[in,out] dest  char* to re-/allocate and append to.
 * \param[in] fmt  printf-like string format.
 * \param[in] args  Arguments for fmt.
 *
 * \a dest may be passed in NULL, or a string previously allocated by talloc.
 * If an existing string is passed in, it will remain associated with whichever
 * ctx it was allocated before, regardless whether it matches \a ctx or not.
 */
#define osmo_talloc_asprintf(ctx, dest, fmt, args ...) \
	do { \
		if (!dest) \
			dest = talloc_asprintf(ctx, fmt, ## args); \
		else \
			dest = talloc_asprintf_append((char*)dest, fmt, ## args); \
	} while (0)

int osmo_constant_time_cmp(const uint8_t *exp, const uint8_t *rel, const int count);
uint64_t osmo_decode_big_endian(const uint8_t *data, size_t data_len);
uint8_t *osmo_encode_big_endian(uint64_t value, size_t data_len);

size_t osmo_strlcpy(char *dst, const char *src, size_t siz);

bool osmo_is_hexstr(const char *str, int min_digits, int max_digits,
		    bool require_even);

bool osmo_identifier_valid(const char *str);
bool osmo_separated_identifiers_valid(const char *str, const char *sep_chars);
void osmo_identifier_sanitize_buf(char *str, const char *sep_chars, char replace_with);

const char *osmo_escape_str(const char *str, int len);
char *osmo_escape_str_buf2(char *buf, size_t bufsize, const char *str, int in_len);
const char *osmo_escape_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
char *osmo_escape_str_c(const void *ctx, const char *str, int in_len);
const char *osmo_quote_str(const char *str, int in_len);
char *osmo_quote_str_buf2(char *buf, size_t bufsize, const char *str, int in_len);
const char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize);
char *osmo_quote_str_c(const void *ctx, const char *str, int in_len);

int osmo_print_n(char *buf, size_t bufsize, const char *str, size_t n);

uint32_t osmo_isqrt32(uint32_t x);

char osmo_luhn(const char* in, int in_len);

/*! State for OSMO_STRBUF_APPEND() and OSMO_STRBUF_PRINTF(). See there for examples. */
struct osmo_strbuf {
	/*! Point to the start of a string buffer. */
	char *buf;
	/*! Total sizeof() the buffer buf points at. */
	size_t len;
	/*! Current writing position in buf (end of the string written so far). */
	char *pos;
	/*! After all OSMO_STRBUF_APPEND operations, reflects the total number of characters that would be written had
	 * buf been large enough. Like snprintf()'s return value, this does not include the terminating nul character.
	 * Hence, to allocate an adequately sized buffer, add 1 to this number. */
	size_t chars_needed;
};

/*! Append a string to a buffer, as printed by an snprintf()-like function and with similar bounds checking.
 * Make sure to never write past the end of the buffer, and collect the total size that would be needed.
 *
 *     // an example function implementation to append: write N spaces.
 *     int print_spaces(char *dst, size_t dst_len, int n)
 *     {
 *             int i;
 *             if (n < 0)
 *                     return -EINVAL;
 *             for (i = 0; i < n && i < dst_len; i++)
 *                     dst[i] = ' ';
 *             if (dst_len)
 *                     dst[OSMO_MIN(dst_len - 1, n)] = '\0';
 *             // return the n that we would have liked to write if space were available:
 *             return n;
 *     }
 *
 *     // append above spaces as well as an snprintf()
 *     void strbuf_example()
 *     {
 *             char buf[23];
 *             struct osmo_strbuf sb = { .buf = buf, .len = sizeof(buf) };
 *
 *             OSMO_STRBUF_APPEND(sb, print_spaces, 5);
 *             OSMO_STRBUF_APPEND(sb, snprintf, "The answer is %d but what is the question?", 42);
 *             OSMO_STRBUF_APPEND(sb, print_spaces, 423423);
 *
 *             printf("%s\n", buf);
 *             printf("would have needed %zu bytes\n", sb.chars_needed);
 *     }
 *
 * \param[inout] STRBUF  A struct osmo_strbuf instance.
 * \param[in] func  A function with a signature of int func(char *dst, size_t dst_len [, args]) with semantics like
 *                  snprintf().
 * \param[in] args  Arguments passed to func, if any.
 */
#define OSMO_STRBUF_APPEND(STRBUF, func, args...) do { \
		if (!(STRBUF).pos) \
			(STRBUF).pos = (STRBUF).buf; \
		size_t _sb_remain = (STRBUF).buf ? (STRBUF).len - ((STRBUF).pos - (STRBUF).buf) : 0; \
		int _sb_l = func((STRBUF).pos, _sb_remain, ##args); \
		if (_sb_l < 0 || _sb_l > _sb_remain) \
			(STRBUF).pos = (STRBUF).buf + (STRBUF).len; \
		else if ((STRBUF).pos) \
			(STRBUF).pos += _sb_l; \
		if (_sb_l > 0) \
			(STRBUF).chars_needed += _sb_l; \
	} while(0)

/*! Shortcut for OSMO_STRBUF_APPEND() invocation using snprintf().
 *
 *     int strbuf_example2(char *buf, size_t buflen)
 *     {
 *             int i;
 *             struct osmo_strbuf sb = { .buf = buf, .len = buflen };
 *
 *             OSMO_STRBUF_PRINTF(sb, "T minus");
 *             for (i = 10; i; i--)
 *                     OSMO_STRBUF_PRINTF(sb, " %d", i);
 *             OSMO_STRBUF_PRINTF(sb, " ... Lift off!");
 *
 *             return sb.chars_needed;
 *     }
 *
 * \param[inout] STRBUF  A struct osmo_strbuf instance.
 * \param[in] fmt  Format string passed to snprintf.
 * \param[in] args  Additional arguments passed to snprintf, if any.
 */
#define OSMO_STRBUF_PRINTF(STRBUF, fmt, args...) \
	OSMO_STRBUF_APPEND(STRBUF, snprintf, fmt, ##args)

/*! Like OSMO_STRBUF_APPEND(), but for function signatures that return the char* buffer instead of a length.
 * When using this function, the final STRBUF.chars_needed may not reflect the actual number of characters needed, since
 * that number cannot be obtained from this kind of function signature.
 * \param[inout] STRBUF  A struct osmo_strbuf instance.
 * \param[in] func  A function with a signature of char *func(char *dst, size_t dst_len [, args]) where
 *                  the returned string is always written to dst.
 * \param[in] args  Arguments passed to func, if any.
 */
#define OSMO_STRBUF_APPEND_NOLEN(STRBUF, func, args...) do { \
		if (!(STRBUF).pos) \
			(STRBUF).pos = (STRBUF).buf; \
		size_t _sb_remain = (STRBUF).buf ? (STRBUF).len - ((STRBUF).pos - (STRBUF).buf) : 0; \
		if (_sb_remain) { \
			func((STRBUF).pos, _sb_remain, ##args); \
		} \
		size_t _sb_l = (STRBUF).pos ? strnlen((STRBUF).pos, _sb_remain) : 0; \
		if (_sb_l > _sb_remain) \
			(STRBUF).pos = (STRBUF).buf + (STRBUF).len; \
		else if ((STRBUF).pos) \
			(STRBUF).pos += _sb_l; \
		(STRBUF).chars_needed += _sb_l; \
	} while(0)

bool osmo_str_startswith(const char *str, const char *startswith_str);

/*! @} */