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-rw-r--r--src/udev/libudev-util.c570
1 files changed, 570 insertions, 0 deletions
diff --git a/src/udev/libudev-util.c b/src/udev/libudev-util.c
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+++ b/src/udev/libudev-util.c
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+/*
+ * 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 = NULL;
+
+ 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 -EINVAL;
+ base[0] = '\0';
+ }
+ if (base == NULL)
+ return -EINVAL;
+ 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);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-01 15:56:46 +0000