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authorbigbiff bigbiff <bigbiff@teamw.in>2013-01-09 15:09:08 +0100
committerbigbiff bigbiff <bigbiff@teamw.in>2013-01-09 15:09:08 +0100
commit9c754053b07a724bdd98d039f34899d6a49115b7 (patch)
tree464885db361a12d83d60cf152142c765562bb92d /exfat/libexfat/lookup.c
parentAdd Samsung TouchWiz decryption (diff)
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Diffstat (limited to 'exfat/libexfat/lookup.c')
-rw-r--r--exfat/libexfat/lookup.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/exfat/libexfat/lookup.c b/exfat/libexfat/lookup.c
new file mode 100644
index 000000000..8c889b2b2
--- /dev/null
+++ b/exfat/libexfat/lookup.c
@@ -0,0 +1,223 @@
+/*
+ lookup.c (02.09.09)
+ exFAT file system implementation library.
+
+ Copyright (C) 2010-2012 Andrew Nayenko
+
+ 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "exfat.h"
+#include <string.h>
+#include <errno.h>
+#include <inttypes.h>
+
+int exfat_opendir(struct exfat* ef, struct exfat_node* dir,
+ struct exfat_iterator* it)
+{
+ int rc;
+
+ exfat_get_node(dir);
+ it->parent = dir;
+ it->current = NULL;
+ rc = exfat_cache_directory(ef, dir);
+ if (rc != 0)
+ exfat_put_node(ef, dir);
+ return rc;
+}
+
+void exfat_closedir(struct exfat* ef, struct exfat_iterator* it)
+{
+ exfat_put_node(ef, it->parent);
+ it->parent = NULL;
+ it->current = NULL;
+}
+
+struct exfat_node* exfat_readdir(struct exfat* ef, struct exfat_iterator* it)
+{
+ if (it->current == NULL)
+ it->current = it->parent->child;
+ else
+ it->current = it->current->next;
+
+ if (it->current != NULL)
+ return exfat_get_node(it->current);
+ else
+ return NULL;
+}
+
+static int compare_char(struct exfat* ef, uint16_t a, uint16_t b)
+{
+ if (a >= ef->upcase_chars || b >= ef->upcase_chars)
+ return (int) a - (int) b;
+
+ return (int) le16_to_cpu(ef->upcase[a]) - (int) le16_to_cpu(ef->upcase[b]);
+}
+
+static int compare_name(struct exfat* ef, const le16_t* a, const le16_t* b)
+{
+ while (le16_to_cpu(*a) && le16_to_cpu(*b))
+ {
+ int rc = compare_char(ef, le16_to_cpu(*a), le16_to_cpu(*b));
+ if (rc != 0)
+ return rc;
+ a++;
+ b++;
+ }
+ return compare_char(ef, le16_to_cpu(*a), le16_to_cpu(*b));
+}
+
+static int lookup_name(struct exfat* ef, struct exfat_node* parent,
+ struct exfat_node** node, const char* name, size_t n)
+{
+ struct exfat_iterator it;
+ le16_t buffer[EXFAT_NAME_MAX + 1];
+ int rc;
+
+ *node = NULL;
+
+ rc = utf8_to_utf16(buffer, name, EXFAT_NAME_MAX, n);
+ if (rc != 0)
+ return rc;
+
+ rc = exfat_opendir(ef, parent, &it);
+ if (rc != 0)
+ return rc;
+ while ((*node = exfat_readdir(ef, &it)))
+ {
+ if (compare_name(ef, buffer, (*node)->name) == 0)
+ {
+ exfat_closedir(ef, &it);
+ return 0;
+ }
+ exfat_put_node(ef, *node);
+ }
+ exfat_closedir(ef, &it);
+ return -ENOENT;
+}
+
+static size_t get_comp(const char* path, const char** comp)
+{
+ const char* end;
+
+ *comp = path + strspn(path, "/"); /* skip leading slashes */
+ end = strchr(*comp, '/');
+ if (end == NULL)
+ return strlen(*comp);
+ else
+ return end - *comp;
+}
+
+int exfat_lookup(struct exfat* ef, struct exfat_node** node,
+ const char* path)
+{
+ struct exfat_node* parent;
+ const char* p;
+ size_t n;
+ int rc;
+
+ /* start from the root directory */
+ parent = *node = exfat_get_node(ef->root);
+ for (p = path; (n = get_comp(p, &p)); p += n)
+ {
+ if (n == 1 && *p == '.') /* skip "." component */
+ continue;
+ rc = lookup_name(ef, parent, node, p, n);
+ if (rc != 0)
+ {
+ exfat_put_node(ef, parent);
+ return rc;
+ }
+ exfat_put_node(ef, parent);
+ parent = *node;
+ }
+ return 0;
+}
+
+static bool is_last_comp(const char* comp, size_t length)
+{
+ const char* p = comp + length;
+
+ return get_comp(p, &p) == 0;
+}
+
+static bool is_allowed(const char* comp, size_t length)
+{
+ size_t i;
+
+ for (i = 0; i < length; i++)
+ switch (comp[i])
+ {
+ case 0x01 ... 0x1f:
+ case '/':
+ case '\\':
+ case ':':
+ case '*':
+ case '?':
+ case '"':
+ case '<':
+ case '>':
+ case '|':
+ return false;
+ }
+ return true;
+}
+
+int exfat_split(struct exfat* ef, struct exfat_node** parent,
+ struct exfat_node** node, le16_t* name, const char* path)
+{
+ const char* p;
+ size_t n;
+ int rc;
+
+ memset(name, 0, (EXFAT_NAME_MAX + 1) * sizeof(le16_t));
+ *parent = *node = exfat_get_node(ef->root);
+ for (p = path; (n = get_comp(p, &p)); p += n)
+ {
+ if (n == 1 && *p == '.')
+ continue;
+ if (is_last_comp(p, n))
+ {
+ if (!is_allowed(p, n))
+ {
+ /* contains characters that are not allowed */
+ exfat_put_node(ef, *parent);
+ return -ENOENT;
+ }
+ rc = utf8_to_utf16(name, p, EXFAT_NAME_MAX, n);
+ if (rc != 0)
+ {
+ exfat_put_node(ef, *parent);
+ return rc;
+ }
+
+ rc = lookup_name(ef, *parent, node, p, n);
+ if (rc != 0 && rc != -ENOENT)
+ {
+ exfat_put_node(ef, *parent);
+ return rc;
+ }
+ return 0;
+ }
+ rc = lookup_name(ef, *parent, node, p, n);
+ if (rc != 0)
+ {
+ exfat_put_node(ef, *parent);
+ return rc;
+ }
+ exfat_put_node(ef, *parent);
+ *parent = *node;
+ }
+ exfat_bug("impossible");
+}