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Diffstat (limited to 'firmware/libosmocore/source/utils.c')
| -rw-r--r-- | firmware/libosmocore/source/utils.c | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/firmware/libosmocore/source/utils.c b/firmware/libosmocore/source/utils.c new file mode 100644 index 0000000..3096572 --- /dev/null +++ b/firmware/libosmocore/source/utils.c @@ -0,0 +1,632 @@ +/* + * (C) 2011 by Harald Welte <laforge@gnumonks.org> + * (C) 2011 by Sylvain Munaut <tnt@246tNt.com> + * (C) 2014 by Nils O. Selåsdal <noselasd@fiane.dyndns.org> + * + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + + +#include <stdbool.h> +#include <string.h> +#include <stdint.h> +#include <errno.h> +#include <stdio.h> +#include <inttypes.h> + +#include <osmocom/core/utils.h> +#include <osmocom/core/bit64gen.h> + + +/*! \addtogroup utils + * @{ + * various utility routines + * + * \file utils.c */ + +static char namebuf[255]; + +/*! get human-readable string for given value + * \param[in] vs Array of value_string tuples + * \param[in] val Value to be converted + * \returns pointer to human-readable string + * + * If val is found in vs, the array's string entry is returned. Otherwise, an + * "unknown" string containing the actual value is composed in a static buffer + * that is reused across invocations. + */ +const char *get_value_string(const struct value_string *vs, uint32_t val) +{ + const char *str = get_value_string_or_null(vs, val); + if (str) + return str; + + snprintf(namebuf, sizeof(namebuf), "unknown 0x%"PRIx32, val); + namebuf[sizeof(namebuf) - 1] = '\0'; + return namebuf; +} + +/*! get human-readable string or NULL for given value + * \param[in] vs Array of value_string tuples + * \param[in] val Value to be converted + * \returns pointer to human-readable string or NULL if val is not found + */ +const char *get_value_string_or_null(const struct value_string *vs, + uint32_t val) +{ + int i; + + for (i = 0;; i++) { + if (vs[i].value == 0 && vs[i].str == NULL) + break; + if (vs[i].value == val) + return vs[i].str; + } + + return NULL; +} + +/*! get numeric value for given human-readable string + * \param[in] vs Array of value_string tuples + * \param[in] str human-readable string + * \returns numeric value (>0) or negative numer in case of error + */ +int get_string_value(const struct value_string *vs, const char *str) +{ + int i; + + for (i = 0;; i++) { + if (vs[i].value == 0 && vs[i].str == NULL) + break; + if (!strcasecmp(vs[i].str, str)) + return vs[i].value; + } + return -EINVAL; +} + +/*! Convert BCD-encoded digit into printable character + * \param[in] bcd A single BCD-encoded digit + * \returns single printable character + */ +char osmo_bcd2char(uint8_t bcd) +{ + if (bcd < 0xa) + return '0' + bcd; + else + return 'A' + (bcd - 0xa); +} + +/*! Convert number in ASCII to BCD value + * \param[in] c ASCII character + * \returns BCD encoded value of character + */ +uint8_t osmo_char2bcd(char c) +{ + if (c >= '0' && c <= '9') + return c - 0x30; + else if (c >= 'A' && c <= 'F') + return 0xa + (c - 'A'); + else if (c >= 'a' && c <= 'f') + return 0xa + (c - 'a'); + else + return 0; +} + +/*! Parse a string containing hexadecimal digits + * \param[in] str string containing ASCII encoded hexadecimal digits + * \param[out] b output buffer + * \param[in] max_len maximum space in output buffer + * \returns number of parsed octets, or -1 on error + */ +int osmo_hexparse(const char *str, uint8_t *b, int max_len) + +{ + char c; + uint8_t v; + const char *strpos; + unsigned int nibblepos = 0; + + memset(b, 0x00, max_len); + + for (strpos = str; (c = *strpos); strpos++) { + /* skip whitespace */ + if (c == ' ' || c == '\t' || c == '\n' || c == '\r') + continue; + + /* If the buffer is too small, error out */ + if (nibblepos >= (max_len << 1)) + return -1; + + if (c >= '0' && c <= '9') + v = c - '0'; + else if (c >= 'a' && c <= 'f') + v = 10 + (c - 'a'); + else if (c >= 'A' && c <= 'F') + v = 10 + (c - 'A'); + else + return -1; + + b[nibblepos >> 1] |= v << (nibblepos & 1 ? 0 : 4); + nibblepos ++; + } + + /* In case of uneven amount of digits, the last byte is not complete + * and that's an error. */ + if (nibblepos & 1) + return -1; + + return nibblepos >> 1; +} + +static char hexd_buff[4096]; +static const char hex_chars[] = "0123456789abcdef"; + +static char *_osmo_hexdump(const unsigned char *buf, int len, const char *delim) +{ + int i; + char *cur = hexd_buff; + + hexd_buff[0] = 0; + for (i = 0; i < len; i++) { + const char *delimp = delim; + int len_remain = sizeof(hexd_buff) - (cur - hexd_buff); + if (len_remain < 3) + break; + + *cur++ = hex_chars[buf[i] >> 4]; + *cur++ = hex_chars[buf[i] & 0xf]; + + while (len_remain > 1 && *delimp) { + *cur++ = *delimp++; + len_remain--; + } + + *cur = 0; + } + hexd_buff[sizeof(hexd_buff)-1] = 0; + return hexd_buff; +} + +/*! Convert a sequence of unpacked bits to ASCII string + * \param[in] bits A sequence of unpacked bits + * \param[in] len Length of bits + */ +char *osmo_ubit_dump(const uint8_t *bits, unsigned int len) +{ + int i; + + if (len > sizeof(hexd_buff)-1) + len = sizeof(hexd_buff)-1; + memset(hexd_buff, 0, sizeof(hexd_buff)); + + for (i = 0; i < len; i++) { + char outch; + switch (bits[i]) { + case 0: + outch = '0'; + break; + case 0xff: + outch = '?'; + break; + case 1: + outch = '1'; + break; + default: + outch = 'E'; + break; + } + hexd_buff[i] = outch; + } + hexd_buff[sizeof(hexd_buff)-1] = 0; + return hexd_buff; +} + +/*! Convert binary sequence to hexadecimal ASCII string + * \param[in] buf pointer to sequence of bytes + * \param[in] len length of buf in number of bytes + * \returns pointer to zero-terminated string + * + * This function will print a sequence of bytes as hexadecimal numbers, + * adding one space character between each byte (e.g. "1a ef d9") + * + * The maximum size of the output buffer is 4096 bytes, i.e. the maximum + * number of input bytes that can be printed in one call is 1365! + */ +char *osmo_hexdump(const unsigned char *buf, int len) +{ + return _osmo_hexdump(buf, len, " "); +} + +/*! Convert binary sequence to hexadecimal ASCII string + * \param[in] buf pointer to sequence of bytes + * \param[in] len length of buf in number of bytes + * \returns pointer to zero-terminated string + * + * This function will print a sequence of bytes as hexadecimal numbers, + * without any space character between each byte (e.g. "1aefd9") + * + * The maximum size of the output buffer is 4096 bytes, i.e. the maximum + * number of input bytes that can be printed in one call is 2048! + */ +char *osmo_hexdump_nospc(const unsigned char *buf, int len) +{ + return _osmo_hexdump(buf, len, ""); +} + +/* Compat with previous typo to preserve abi */ +char *osmo_osmo_hexdump_nospc(const unsigned char *buf, int len) +#if defined(__MACH__) && defined(__APPLE__) + ; +#else + __attribute__((weak, alias("osmo_hexdump_nospc"))); +#endif + +#include <ctype.h> +/*! Convert an entire string to lower case + * \param[out] out output string, caller-allocated + * \param[in] in input string + */ +void osmo_str2lower(char *out, const char *in) +{ + unsigned int i; + + for (i = 0; i < strlen(in); i++) + out[i] = tolower((const unsigned char)in[i]); + out[strlen(in)] = '\0'; +} + +/*! Convert an entire string to upper case + * \param[out] out output string, caller-allocated + * \param[in] in input string + */ +void osmo_str2upper(char *out, const char *in) +{ + unsigned int i; + + for (i = 0; i < strlen(in); i++) + out[i] = toupper((const unsigned char)in[i]); + out[strlen(in)] = '\0'; +} + +/*! Wishful thinking to generate a constant time compare + * \param[in] exp Expected data + * \param[in] rel Comparison value + * \param[in] count Number of bytes to compare + * \returns 1 in case \a exp equals \a rel; zero otherwise + * + * Compare count bytes of exp to rel. Return 0 if they are identical, 1 + * otherwise. Do not return a mismatch on the first mismatching byte, + * but always compare all bytes, regardless. The idea is that the amount of + * matching bytes cannot be inferred from the time the comparison took. */ +int osmo_constant_time_cmp(const uint8_t *exp, const uint8_t *rel, const int count) +{ + int x = 0, i; + + for (i = 0; i < count; ++i) + x |= exp[i] ^ rel[i]; + + /* if x is zero, all data was identical */ + return x? 1 : 0; +} + +/*! Generic retrieval of 1..8 bytes as big-endian uint64_t + * \param[in] data Input data as byte-array + * \param[in] data_len Length of \a data in octets + * \returns uint64_t of \a data interpreted as big-endian + * + * This is like osmo_load64be_ext, except that if data_len is less than + * sizeof(uint64_t), the data is interpreted as the least significant bytes + * (osmo_load64be_ext loads them as the most significant bytes into the + * returned uint64_t). In this way, any integer size up to 64 bits can be + * decoded conveniently by using sizeof(), without the need to call specific + * numbered functions (osmo_load16, 32, ...). */ +uint64_t osmo_decode_big_endian(const uint8_t *data, size_t data_len) +{ + uint64_t value = 0; + + while (data_len > 0) { + value = (value << 8) + *data; + data += 1; + data_len -= 1; + } + + return value; +} + +/*! Generic big-endian encoding of big endian number up to 64bit + * \param[in] value unsigned integer value to be stored + * \param[in] data_len number of octets + * \returns static buffer containing big-endian stored value + * + * This is like osmo_store64be_ext, except that this returns a static buffer of + * the result (for convenience, but not threadsafe). If data_len is less than + * sizeof(uint64_t), only the least significant bytes of value are encoded. */ +uint8_t *osmo_encode_big_endian(uint64_t value, size_t data_len) +{ + static uint8_t buf[sizeof(uint64_t)]; + OSMO_ASSERT(data_len <= ARRAY_SIZE(buf)); + osmo_store64be_ext(value, buf, data_len); + return buf; +} + +/*! Copy a C-string into a sized buffer + * \param[in] src source string + * \param[out] dst destination string + * \param[in] siz size of the \a dst buffer + * \returns length of \a src + * + * Copy at most \a siz bytes from \a src to \a dst, ensuring that the result is + * NUL terminated. The NUL character is included in \a siz, i.e. passing the + * actual sizeof(*dst) is correct. + */ +size_t osmo_strlcpy(char *dst, const char *src, size_t siz) +{ + size_t ret = src ? strlen(src) : 0; + + if (siz) { + size_t len = (ret >= siz) ? siz - 1 : ret; + if (src) + memcpy(dst, src, len); + dst[len] = '\0'; + } + return ret; +} + +/*! Validate that a given string is a hex string within given size limits. + * Note that each hex digit amounts to a nibble, so if checking for a hex + * string to result in N bytes, pass amount of digits as 2*N. + * \param str A nul-terminated string to validate, or NULL. + * \param min_digits least permitted amount of digits. + * \param max_digits most permitted amount of digits. + * \param require_even if true, require an even amount of digits. + * \returns true when the hex_str contains only hexadecimal digits (no + * whitespace) and matches the requested length; also true + * when min_digits <= 0 and str is NULL. + */ +bool osmo_is_hexstr(const char *str, int min_digits, int max_digits, + bool require_even) +{ + int len; + /* Use unsigned char * to avoid a compiler warning of + * "error: array subscript has type 'char' [-Werror=char-subscripts]" */ + const unsigned char *pos = (const unsigned char*)str; + if (!pos) + return min_digits < 1; + for (len = 0; *pos && len < max_digits; len++, pos++) + if (!isxdigit(*pos)) + return false; + if (len < min_digits) + return false; + /* With not too many digits, we should have reached *str == nul */ + if (*pos) + return false; + if (require_even && (len & 1)) + return false; + + return true; +} + +/*! Determine if a given identifier is valid, i.e. doesn't contain illegal chars + * \param[in] str String to validate + * \param[in] sep_chars Permitted separation characters between identifiers. + * \returns true in case \a str contains only valid identifiers and sep_chars, false otherwise + */ +bool osmo_separated_identifiers_valid(const char *str, const char *sep_chars) +{ + /* characters that are illegal in names */ + static const char illegal_chars[] = "., {}[]()<>|~\\^`'\"?=;/+*&%$#!"; + unsigned int i; + size_t len; + + /* an empty string is not a valid identifier */ + if (!str || (len = strlen(str)) == 0) + return false; + + for (i = 0; i < len; i++) { + if (sep_chars && strchr(sep_chars, str[i])) + continue; + /* check for 7-bit ASCII */ + if (str[i] & 0x80) + return false; + if (!isprint((int)str[i])) + return false; + /* check for some explicit reserved control characters */ + if (strchr(illegal_chars, str[i])) + return false; + } + + return true; +} + +/*! Determine if a given identifier is valid, i.e. doesn't contain illegal chars + * \param[in] str String to validate + * \returns true in case \a str contains valid identifier, false otherwise + */ +bool osmo_identifier_valid(const char *str) +{ + return osmo_separated_identifiers_valid(str, NULL); +} + +/*! Return the string with all non-printable characters escaped. + * \param[in] str A string that may contain any characters. + * \param[in] len Pass -1 to print until nul char, or >= 0 to force a length. + * \param[inout] buf string buffer to write escaped characters to. + * \param[in] bufsize size of \a buf. + * \returns buf containing an escaped representation, possibly truncated, or str itself. + */ +const char *osmo_escape_str_buf(const char *str, int in_len, char *buf, size_t bufsize) +{ + int in_pos = 0; + int next_unprintable = 0; + int out_pos = 0; + char *out = buf; + /* -1 to leave space for a final \0 */ + int out_len = bufsize-1; + + if (!str) + return "(null)"; + + if (in_len < 0) + in_len = strlen(str); + + while (in_pos < in_len) { + for (next_unprintable = in_pos; + next_unprintable < in_len && isprint((int)str[next_unprintable]) + && str[next_unprintable] != '"' + && str[next_unprintable] != '\\'; + next_unprintable++); + + if (next_unprintable == in_len + && in_pos == 0) + return str; + + while (in_pos < next_unprintable && out_pos < out_len) + out[out_pos++] = str[in_pos++]; + + if (out_pos == out_len || in_pos == in_len) + goto done; + + switch (str[next_unprintable]) { +#define BACKSLASH_CASE(c, repr) \ + case c: \ + if (out_pos > out_len-2) \ + goto done; \ + out[out_pos++] = '\\'; \ + out[out_pos++] = repr; \ + break + + BACKSLASH_CASE('\n', 'n'); + BACKSLASH_CASE('\r', 'r'); + BACKSLASH_CASE('\t', 't'); + BACKSLASH_CASE('\0', '0'); + BACKSLASH_CASE('\a', 'a'); + BACKSLASH_CASE('\b', 'b'); + BACKSLASH_CASE('\v', 'v'); + BACKSLASH_CASE('\f', 'f'); + BACKSLASH_CASE('\\', '\\'); + BACKSLASH_CASE('"', '"'); +#undef BACKSLASH_CASE + + default: + out_pos += snprintf(&out[out_pos], out_len - out_pos, "\\%u", (unsigned char)str[in_pos]); + if (out_pos > out_len) { + out_pos = out_len; + goto done; + } + break; + } + in_pos ++; + } + +done: + out[out_pos] = '\0'; + return out; +} + +/*! Return the string with all non-printable characters escaped. + * Call osmo_escape_str_buf() with a static buffer. + * \param[in] str A string that may contain any characters. + * \param[in] len Pass -1 to print until nul char, or >= 0 to force a length. + * \returns buf containing an escaped representation, possibly truncated, or str itself. + */ +const char *osmo_escape_str(const char *str, int in_len) +{ + return osmo_escape_str_buf(str, in_len, namebuf, sizeof(namebuf)); +} + +/*! Like osmo_escape_str(), but returns double-quotes around a string, or "NULL" for a NULL string. + * This allows passing any char* value and get its C representation as string. + * \param[in] str A string that may contain any characters. + * \param[in] len Pass -1 to print until nul char, or >= 0 to force a length. + * \returns buf containing an escaped representation, possibly truncated, or str itself. + */ +const char *osmo_quote_str_buf(const char *str, int in_len, char *buf, size_t bufsize) +{ + const char *res; + int l; + if (!str) + return "NULL"; + if (bufsize < 3) + return "<buf-too-small>"; + buf[0] = '"'; + res = osmo_escape_str_buf(str, in_len, buf + 1, bufsize - 2); + /* if osmo_escape_str_buf() returned the str itself, we need to copy it to buf to be able to + * quote it. */ + if (res == str) { + /* max_len = bufsize - two quotes - nul term */ + int max_len = bufsize - 2 - 1; + if (in_len >= 0) + max_len = OSMO_MIN(in_len, max_len); + /* It is not allowed to pass unterminated strings into osmo_strlcpy() :/ */ + strncpy(buf + 1, str, max_len); + buf[1 + max_len] = '\0'; + } + l = strlen(buf); + buf[l] = '"'; + buf[l+1] = '\0'; /* both osmo_escape_str_buf() and max_len above ensure room for '\0' */ + return buf; +} + +const char *osmo_quote_str(const char *str, int in_len) +{ + return osmo_quote_str_buf(str, in_len, namebuf, sizeof(namebuf)); +} + +/*! perform an integer square root operation on unsigned 32bit integer. + * This implementation is taken from "Hacker's Delight" Figure 11-1 "Integer square root, Newton's + * method", which can also be found at http://www.hackersdelight.org/hdcodetxt/isqrt.c.txt */ +uint32_t osmo_isqrt32(uint32_t x) +{ + uint32_t x1; + int s, g0, g1; + + if (x <= 1) + return x; + + s = 1; + x1 = x - 1; + if (x1 > 0xffff) { + s = s + 8; + x1 = x1 >> 16; + } + if (x1 > 0xff) { + s = s + 4; + x1 = x1 >> 8; + } + if (x1 > 0xf) { + s = s + 2; + x1 = x1 >> 4; + } + if (x1 > 0x3) { + s = s + 1; + } + + g0 = 1 << s; /* g0 = 2**s */ + g1 = (g0 + (x >> s)) >> 1; /* g1 = (g0 + x/g0)/2 */ + + /* converges after four to five divisions for arguments up to 16,785,407 */ + while (g1 < g0) { + g0 = g1; + g1 = (g0 + (x/g0)) >> 1; + } + return g0; +} + +/*! @} */ |