diff options
Diffstat (limited to 'udev/lib')
| -rw-r--r-- | udev/lib/libudev-private.h | 1 | ||||
| -rw-r--r-- | udev/lib/libudev-util.c | 177 |
2 files changed, 178 insertions, 0 deletions
diff --git a/udev/lib/libudev-private.h b/udev/lib/libudev-private.h index 32837e368d..1f4abc07ba 100644 --- a/udev/lib/libudev-private.h +++ b/udev/lib/libudev-private.h @@ -123,4 +123,5 @@ extern size_t util_path_decode(char *s); extern void util_remove_trailing_chars(char *path, char c); extern size_t util_strlcpy(char *dst, const char *src, size_t size); extern size_t util_strlcat(char *dst, const char *src, size_t size); +extern int util_replace_chars(char *str, const char *white); #endif diff --git a/udev/lib/libudev-util.c b/udev/lib/libudev-util.c index ae0adf4b88..7aea8c67fb 100644 --- a/udev/lib/libudev-util.c +++ b/udev/lib/libudev-util.c @@ -26,6 +26,7 @@ #include <errno.h> #include <string.h> #include <dirent.h> +#include <ctype.h> #include <sys/stat.h> #include "libudev.h" @@ -255,3 +256,179 @@ size_t util_strlcat(char *dst, const char *src, size_t size) *q = '\0'; return bytes; } + +/* 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; +} + +/* 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; + + /* accept whitelist */ + if (white != NULL && strchr(white, str[i]) != NULL) { + i++; + continue; + } + + /* accept plain ascii char */ + if ((str[i] >= '0' && str[i] <= '9') || + (str[i] >= 'A' && str[i] <= 'Z') || + (str[i] >= 'a' && str[i] <= 'z')) { + 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]) && strchr(white, ' ') != NULL) { + str[i] = ' '; + i++; + replaced++; + continue; + } + + /* everything else is replaced with '_' */ + str[i] = '_'; + i++; + replaced++; + } + + return replaced; +} |