diff options
author | Kay Sievers <kay.sievers@vrfy.org> | 2012-01-05 22:41:45 +0100 |
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committer | Kay Sievers <kay.sievers@vrfy.org> | 2012-01-06 05:07:10 +0100 |
commit | ad29a9f14fa8b1932c0e418bfcf1c10ce6a35a33 (patch) | |
tree | 9212c3d9d937234c25d19b993664b8ed164869a5 /src/libudev-util.c | |
parent | 9fbe27d9d6dc6e4530ce904d35c74326e415e34e (diff) |
merge udev/, libudev/, systemd/ files in src/; move extras/ to src/
Diffstat (limited to 'src/libudev-util.c')
-rw-r--r-- | src/libudev-util.c | 568 |
1 files changed, 568 insertions, 0 deletions
diff --git a/src/libudev-util.c b/src/libudev-util.c new file mode 100644 index 0000000000..559aa06dc6 --- /dev/null +++ b/src/libudev-util.c @@ -0,0 +1,568 @@ +/* + * libudev - interface to udev device information + * + * Copyright (C) 2008-2011 Kay Sievers <kay.sievers@vrfy.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stddef.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <dirent.h> +#include <ctype.h> +#include <fcntl.h> +#include <time.h> +#include <sys/stat.h> + +#include "libudev.h" +#include "libudev-private.h" + +/** + * SECTION:libudev-util + * @short_description: utils + */ + +ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size) +{ + char path[UTIL_PATH_SIZE]; + char target[UTIL_PATH_SIZE]; + ssize_t len; + const char *pos; + + util_strscpyl(path, sizeof(path), syspath, "/", slink, NULL); + len = readlink(path, target, sizeof(target)); + if (len <= 0 || len == (ssize_t)sizeof(target)) + return -1; + target[len] = '\0'; + pos = strrchr(target, '/'); + if (pos == NULL) + return -1; + pos = &pos[1]; + dbg(udev, "resolved link to: '%s'\n", pos); + return util_strscpy(value, size, pos); +} + +int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size) +{ + char link_target[UTIL_PATH_SIZE]; + + ssize_t len; + int i; + int back; + char *base; + + len = readlink(syspath, link_target, sizeof(link_target)); + if (len <= 0 || len == (ssize_t)sizeof(link_target)) + return -1; + link_target[len] = '\0'; + dbg(udev, "path link '%s' points to '%s'\n", syspath, link_target); + + for (back = 0; strncmp(&link_target[back * 3], "../", 3) == 0; back++) + ; + dbg(udev, "base '%s', tail '%s', back %i\n", syspath, &link_target[back * 3], back); + for (i = 0; i <= back; i++) { + base = strrchr(syspath, '/'); + if (base == NULL) + return -1; + base[0] = '\0'; + } + dbg(udev, "after moving back '%s'\n", syspath); + util_strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL); + return 0; +} + +int util_log_priority(const char *priority) +{ + char *endptr; + int prio; + + prio = strtol(priority, &endptr, 10); + if (endptr[0] == '\0' || isspace(endptr[0])) + return prio; + if (strncmp(priority, "err", 3) == 0) + return LOG_ERR; + if (strncmp(priority, "info", 4) == 0) + return LOG_INFO; + if (strncmp(priority, "debug", 5) == 0) + return LOG_DEBUG; + return 0; +} + +size_t util_path_encode(const char *src, char *dest, size_t size) +{ + size_t i, j; + + for (i = 0, j = 0; src[i] != '\0'; i++) { + if (src[i] == '/') { + if (j+4 >= size) { + j = 0; + break; + } + memcpy(&dest[j], "\\x2f", 4); + j += 4; + } else if (src[i] == '\\') { + if (j+4 >= size) { + j = 0; + break; + } + memcpy(&dest[j], "\\x5c", 4); + j += 4; + } else { + if (j+1 >= size) { + j = 0; + break; + } + dest[j] = src[i]; + j++; + } + } + dest[j] = '\0'; + return j; +} + +size_t util_path_decode(char *s) +{ + size_t i, j; + + for (i = 0, j = 0; s[i] != '\0'; j++) { + if (memcmp(&s[i], "\\x2f", 4) == 0) { + s[j] = '/'; + i += 4; + } else if (memcmp(&s[i], "\\x5c", 4) == 0) { + s[j] = '\\'; + i += 4; + } else { + s[j] = s[i]; + i++; + } + } + s[j] = '\0'; + return j; +} + +void util_remove_trailing_chars(char *path, char c) +{ + size_t len; + + if (path == NULL) + return; + len = strlen(path); + while (len > 0 && path[len-1] == c) + path[--len] = '\0'; +} + +/* + * Concatenates strings. In any case, terminates in _all_ cases with '\0' + * and moves the @dest pointer forward to the added '\0'. Returns the + * remaining size, and 0 if the string was truncated. + */ +size_t util_strpcpy(char **dest, size_t size, const char *src) +{ + size_t len; + + len = strlen(src); + if (len >= size) { + if (size > 1) + *dest = mempcpy(*dest, src, size-1); + size = 0; + *dest[0] = '\0'; + } else { + if (len > 0) { + *dest = mempcpy(*dest, src, len); + size -= len; + } + *dest[0] = '\0'; + } + return size; +} + +/* concatenates list of strings, moves dest forward */ +size_t util_strpcpyl(char **dest, size_t size, const char *src, ...) +{ + va_list va; + + va_start(va, src); + do { + size = util_strpcpy(dest, size, src); + src = va_arg(va, char *); + } while (src != NULL); + va_end(va); + + return size; +} + +/* copies string */ +size_t util_strscpy(char *dest, size_t size, const char *src) +{ + char *s; + + s = dest; + return util_strpcpy(&s, size, src); +} + +/* concatenates list of strings */ +size_t util_strscpyl(char *dest, size_t size, const char *src, ...) +{ + va_list va; + char *s; + + va_start(va, src); + s = dest; + do { + size = util_strpcpy(&s, size, src); + src = va_arg(va, char *); + } while (src != NULL); + va_end(va); + + return size; +} + +/* count of characters used to encode one unicode char */ +static int utf8_encoded_expected_len(const char *str) +{ + unsigned char c = (unsigned char)str[0]; + + if (c < 0x80) + return 1; + if ((c & 0xe0) == 0xc0) + return 2; + if ((c & 0xf0) == 0xe0) + return 3; + if ((c & 0xf8) == 0xf0) + return 4; + if ((c & 0xfc) == 0xf8) + return 5; + if ((c & 0xfe) == 0xfc) + return 6; + return 0; +} + +/* decode one unicode char */ +static int utf8_encoded_to_unichar(const char *str) +{ + int unichar; + int len; + int i; + + len = utf8_encoded_expected_len(str); + switch (len) { + case 1: + return (int)str[0]; + case 2: + unichar = str[0] & 0x1f; + break; + case 3: + unichar = (int)str[0] & 0x0f; + break; + case 4: + unichar = (int)str[0] & 0x07; + break; + case 5: + unichar = (int)str[0] & 0x03; + break; + case 6: + unichar = (int)str[0] & 0x01; + break; + default: + return -1; + } + + for (i = 1; i < len; i++) { + if (((int)str[i] & 0xc0) != 0x80) + return -1; + unichar <<= 6; + unichar |= (int)str[i] & 0x3f; + } + + return unichar; +} + +/* expected size used to encode one unicode char */ +static int utf8_unichar_to_encoded_len(int unichar) +{ + if (unichar < 0x80) + return 1; + if (unichar < 0x800) + return 2; + if (unichar < 0x10000) + return 3; + if (unichar < 0x200000) + return 4; + if (unichar < 0x4000000) + return 5; + return 6; +} + +/* check if unicode char has a valid numeric range */ +static int utf8_unichar_valid_range(int unichar) +{ + if (unichar > 0x10ffff) + return 0; + if ((unichar & 0xfffff800) == 0xd800) + return 0; + if ((unichar > 0xfdcf) && (unichar < 0xfdf0)) + return 0; + if ((unichar & 0xffff) == 0xffff) + return 0; + return 1; +} + +/* validate one encoded unicode char and return its length */ +static int utf8_encoded_valid_unichar(const char *str) +{ + int len; + int unichar; + int i; + + len = utf8_encoded_expected_len(str); + if (len == 0) + return -1; + + /* ascii is valid */ + if (len == 1) + return 1; + + /* check if expected encoded chars are available */ + for (i = 0; i < len; i++) + if ((str[i] & 0x80) != 0x80) + return -1; + + unichar = utf8_encoded_to_unichar(str); + + /* check if encoded length matches encoded value */ + if (utf8_unichar_to_encoded_len(unichar) != len) + return -1; + + /* check if value has valid range */ + if (!utf8_unichar_valid_range(unichar)) + return -1; + + return len; +} + +int util_replace_whitespace(const char *str, char *to, size_t len) +{ + size_t i, j; + + /* strip trailing whitespace */ + len = strnlen(str, len); + while (len && isspace(str[len-1])) + len--; + + /* strip leading whitespace */ + i = 0; + while (isspace(str[i]) && (i < len)) + i++; + + j = 0; + while (i < len) { + /* substitute multiple whitespace with a single '_' */ + if (isspace(str[i])) { + while (isspace(str[i])) + i++; + to[j++] = '_'; + } + to[j++] = str[i++]; + } + to[j] = '\0'; + return 0; +} + +static int is_whitelisted(char c, const char *white) +{ + if ((c >= '0' && c <= '9') || + (c >= 'A' && c <= 'Z') || + (c >= 'a' && c <= 'z') || + strchr("#+-.:=@_", c) != NULL || + (white != NULL && strchr(white, c) != NULL)) + return 1; + return 0; +} + +/* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */ +int util_replace_chars(char *str, const char *white) +{ + size_t i = 0; + int replaced = 0; + + while (str[i] != '\0') { + int len; + + if (is_whitelisted(str[i], white)) { + i++; + continue; + } + + /* accept hex encoding */ + if (str[i] == '\\' && str[i+1] == 'x') { + i += 2; + continue; + } + + /* accept valid utf8 */ + len = utf8_encoded_valid_unichar(&str[i]); + if (len > 1) { + i += len; + continue; + } + + /* if space is allowed, replace whitespace with ordinary space */ + if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) { + str[i] = ' '; + i++; + replaced++; + continue; + } + + /* everything else is replaced with '_' */ + str[i] = '_'; + i++; + replaced++; + } + return replaced; +} + +/** + * udev_util_encode_string: + * @str: input string to be encoded + * @str_enc: output string to store the encoded input string + * @len: maximum size of the output string, which may be + * four times as long as the input string + * + * Encode all potentially unsafe characters of a string to the + * corresponding 2 char hex value prefixed by '\x'. + * + * Returns: 0 if the entire string was copied, non-zero otherwise. + **/ +UDEV_EXPORT int udev_util_encode_string(const char *str, char *str_enc, size_t len) +{ + size_t i, j; + + if (str == NULL || str_enc == NULL) + return -1; + + for (i = 0, j = 0; str[i] != '\0'; i++) { + int seqlen; + + seqlen = utf8_encoded_valid_unichar(&str[i]); + if (seqlen > 1) { + if (len-j < (size_t)seqlen) + goto err; + memcpy(&str_enc[j], &str[i], seqlen); + j += seqlen; + i += (seqlen-1); + } else if (str[i] == '\\' || !is_whitelisted(str[i], NULL)) { + if (len-j < 4) + goto err; + sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]); + j += 4; + } else { + if (len-j < 1) + goto err; + str_enc[j] = str[i]; + j++; + } + } + if (len-j < 1) + goto err; + str_enc[j] = '\0'; + return 0; +err: + return -1; +} + +/* + * http://sites.google.com/site/murmurhash/ + * + * All code is released to the public domain. For business purposes, + * Murmurhash is under the MIT license. + * + */ +static unsigned int murmur_hash2(const char *key, int len, unsigned int seed) +{ + /* + * 'm' and 'r' are mixing constants generated offline. + * They're not really 'magic', they just happen to work well. + */ + const unsigned int m = 0x5bd1e995; + const int r = 24; + + /* initialize the hash to a 'random' value */ + unsigned int h = seed ^ len; + + /* mix 4 bytes at a time into the hash */ + const unsigned char * data = (const unsigned char *)key; + + while(len >= 4) { + unsigned int k = *(unsigned int *)data; + + k *= m; + k ^= k >> r; + k *= m; + h *= m; + h ^= k; + + data += 4; + len -= 4; + } + + /* handle the last few bytes of the input array */ + switch(len) { + case 3: + h ^= data[2] << 16; + case 2: + h ^= data[1] << 8; + case 1: + h ^= data[0]; + h *= m; + }; + + /* do a few final mixes of the hash to ensure the last few bytes are well-incorporated */ + h ^= h >> 13; + h *= m; + h ^= h >> 15; + + return h; +} + +unsigned int util_string_hash32(const char *str) +{ + return murmur_hash2(str, strlen(str), 0); +} + +/* get a bunch of bit numbers out of the hash, and set the bits in our bit field */ +uint64_t util_string_bloom64(const char *str) +{ + uint64_t bits = 0; + unsigned int hash = util_string_hash32(str); + + bits |= 1LLU << (hash & 63); + bits |= 1LLU << ((hash >> 6) & 63); + bits |= 1LLU << ((hash >> 12) & 63); + bits |= 1LLU << ((hash >> 18) & 63); + return bits; +} + +#define USEC_PER_SEC 1000000ULL +#define NSEC_PER_USEC 1000ULL +unsigned long long ts_usec(const struct timespec *ts) +{ + return (unsigned long long) ts->tv_sec * USEC_PER_SEC + + (unsigned long long) ts->tv_nsec / NSEC_PER_USEC; +} + +unsigned long long now_usec(void) +{ + struct timespec ts; + + if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) + return 0; + return ts_usec(&ts); +} |