add uft8 validation for safe volume label exporting

We will not support any other character encoding than plain ascii
or utf8 for volume labels. All invalid utf8 and non-ascii characters
are substituted for security reasons. No options, no fancy heuristics.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

diff --git a/Makefile b/Makefile
index 1c1280a7dcddb636d7fa3bb22cb79d4407ac9245..8f99330967b65ba7ded8c42eb5ffb632bc957e13 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -147,6 +147,7 @@ UDEV_OBJS = \
        udev_rules.o                    \
        udev_rules_parse.o              \
        udev_utils.o                    \
+       udev_utils_string.o             \
        udev_utils_file.o               \
        udev_utils_run.o                \
        udev_libc_wrapper.o

diff --git a/udev_utils.c b/udev_utils.c
index fc1e2e1f7e836f59422f258d273d067a3beee361..c7292d0f045765a24241ca3044e2157e2b993278 100644 (file)
--- a/udev_utils.c
+++ b/udev_utils.c
@@ -36,69 +36,6 @@
 #include "udev_utils.h"
 #include "list.h"
 
-/* compare string with pattern (supports * ? [0-9] [!A-Z]) */
-int strcmp_pattern(const char *p, const char *s)
-{
-       if (s[0] == '\0') {
-               while (p[0] == '*')
-                       p++;
-               return (p[0] != '\0');
-       }
-       switch (p[0]) {
-       case '[':
-               {
-                       int not = 0;
-                       p++;
-                       if (p[0] == '!') {
-                               not = 1;
-                               p++;
-                       }
-                       while ((p[0] != '\0') && (p[0] != ']')) {
-                               int match = 0;
-                               if (p[1] == '-') {
-                                       if ((s[0] >= p[0]) && (s[0] <= p[2]))
-                                               match = 1;
-                                       p += 3;
-                               } else {
-                                       match = (p[0] == s[0]);
-                                       p++;
-                               }
-                               if (match ^ not) {
-                                       while ((p[0] != '\0') && (p[0] != ']'))
-                                               p++;
-                                       if (p[0] == ']')
-                                               return strcmp_pattern(p+1, s+1);
-                               }
-                       }
-               }
-               break;
-       case '*':
-               if (strcmp_pattern(p, s+1))
-                       return strcmp_pattern(p+1, s);
-               return 0;
-       case '\0':
-               if (s[0] == '\0') {
-                       return 0;
-               }
-               break;
-       default:
-               if ((p[0] == s[0]) || (p[0] == '?'))
-                       return strcmp_pattern(p+1, s+1);
-               break;
-       }
-       return 1;
-}
-
-int string_is_true(const char *str)
-{
-       if (strcasecmp(str, "true") == 0)
-               return 1;
-       if (strcasecmp(str, "yes") == 0)
-               return 1;
-       if (strcasecmp(str, "1") == 0)
-               return 1;
-       return 0;
-}
 
 int log_priority(const char *priority)
 {
@@ -143,27 +80,6 @@ int kernel_release_satisfactory(unsigned int version, unsigned int patchlevel, u
                return 0;
 }
 
-void replace_untrusted_chars(char *string)
-{
-       size_t len;
-
-       for (len = 0; string[len] != '\0'; len++) {
-               if (strchr(";,~\\()\'", string[len])) {
-                       info("replace '%c' in '%s'", string[len], string);
-                       string[len] = '_';
-               }
-       }
-}
-
-void remove_trailing_char(char *path, char c)
-{
-       size_t len;
-
-       len = strlen(path);
-       while (len > 0 && path[len-1] == c)
-               path[--len] = '\0';
-}
-
 int name_list_add(struct list_head *name_list, const char *name, int sort)
 {
        struct name_entry *loop_name;

diff --git a/udev_utils.h b/udev_utils.h
index 0a307526b71455112fff491f91bda4b51e4f2b33..a07d8d2b7cecb6f152ef34f2631604b14dd4d68c 100644 (file)
--- a/udev_utils.h
+++ b/udev_utils.h
@@ -31,22 +31,29 @@ struct name_entry {
        char name[PATH_SIZE];
 };
 
-extern int strcmp_pattern(const char *p, const char *s);
-extern int kernel_release_satisfactory(unsigned int version, unsigned int patchlevel, unsigned int sublevel);
-extern int create_path(const char *path);
+/* udev_utils.c */
 extern int log_priority(const char *priority);
-extern int string_is_true(const char *str);
-extern int parse_get_pair(char **orig_string, char **left, char **right);
-extern int unlink_secure(const char *filename);
-extern int file_map(const char *filename, char **buf, size_t *bufsize);
-extern void file_unmap(void *buf, size_t bufsize);
-extern size_t buf_get_line(const char *buf, size_t buflen, size_t cur);
-extern void remove_trailing_char(char *path, char c);
-extern void replace_untrusted_chars(char *string);
+extern int kernel_release_satisfactory(unsigned int version, unsigned int patchlevel, unsigned int sublevel);
 extern int name_list_add(struct list_head *name_list, const char *name, int sort);
 extern int name_list_key_add(struct list_head *name_list, const char *key, const char *value);
 extern void name_list_cleanup(struct list_head *name_list);
 extern int add_matching_files(struct list_head *name_list, const char *dirname, const char *suffix);
+
+/* udev_utils_string.c */
+extern int strcmp_pattern(const char *p, const char *s);
+extern int string_is_true(const char *str);
+extern void replace_untrusted_chars(char *string);
+extern void remove_trailing_char(char *path, char c);
+extern int utf8_encoded_valid_unichar(const char *str);
+
+/* udev_utils_file.c */
+extern int create_path(const char *path);
+extern int file_map(const char *filename, char **buf, size_t *bufsize);
+extern void file_unmap(void *buf, size_t bufsize);
+extern int unlink_secure(const char *filename);
+extern size_t buf_get_line(const char *buf, size_t buflen, size_t cur);
+
+/* udev_utils_run.c */
 extern int pass_env_to_socket(const char *name, const char *devpath, const char *action);
 extern int run_program(const char *command, const char *subsystem,
                       char *result, size_t ressize, size_t *reslen, int log);

diff --git a/udev_utils_string.c b/udev_utils_string.c
new file mode 100644 (file)
index 0000000..a30181e
--- /dev/null
+++ b/udev_utils_string.c
@@ -0,0 +1,243 @@
+/*
+ * udev_utils_string.c - string manipulation
+ *
+ * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ *     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 version 2 of the License.
+ * 
+ *     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.,
+ *     675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <syslog.h>
+#include <sys/utsname.h>
+
+#include "udev_libc_wrapper.h"
+#include "udev.h"
+#include "logging.h"
+#include "udev_utils.h"
+#include "list.h"
+
+/* compare string with pattern (like fnmatch(), supports * ? [0-9] [!A-Z]) */
+int strcmp_pattern(const char *p, const char *s)
+{
+       if (s[0] == '\0') {
+               while (p[0] == '*')
+                       p++;
+               return (p[0] != '\0');
+       }
+       switch (p[0]) {
+       case '[':
+               {
+                       int not = 0;
+                       p++;
+                       if (p[0] == '!') {
+                               not = 1;
+                               p++;
+                       }
+                       while ((p[0] != '\0') && (p[0] != ']')) {
+                               int match = 0;
+                               if (p[1] == '-') {
+                                       if ((s[0] >= p[0]) && (s[0] <= p[2]))
+                                               match = 1;
+                                       p += 3;
+                               } else {
+                                       match = (p[0] == s[0]);
+                                       p++;
+                               }
+                               if (match ^ not) {
+                                       while ((p[0] != '\0') && (p[0] != ']'))
+                                               p++;
+                                       if (p[0] == ']')
+                                               return strcmp_pattern(p+1, s+1);
+                               }
+                       }
+               }
+               break;
+       case '*':
+               if (strcmp_pattern(p, s+1))
+                       return strcmp_pattern(p+1, s);
+               return 0;
+       case '\0':
+               if (s[0] == '\0') {
+                       return 0;
+               }
+               break;
+       default:
+               if ((p[0] == s[0]) || (p[0] == '?'))
+                       return strcmp_pattern(p+1, s+1);
+               break;
+       }
+       return 1;
+}
+
+int string_is_true(const char *str)
+{
+       if (strcasecmp(str, "true") == 0)
+               return 1;
+       if (strcasecmp(str, "yes") == 0)
+               return 1;
+       if (strcasecmp(str, "1") == 0)
+               return 1;
+       return 0;
+}
+
+void remove_trailing_char(char *path, char c)
+{
+       size_t len;
+
+       len = strlen(path);
+       while (len > 0 && path[len-1] == c)
+               path[--len] = '\0';
+}
+
+/* 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 */
+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;
+}
+
+void replace_untrusted_chars(char *string)
+{
+       size_t len;
+
+       for (len = 0; string[len] != '\0'; len++) {
+               if (strchr(";,~\\()\'", string[len]))
+                       string[len] = '_';
+       }
+}