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-rw-r--r--grub-core/fs/archelp.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/grub-core/fs/archelp.c b/grub-core/fs/archelp.c
new file mode 100644
index 0000000..0cf544f
--- /dev/null
+++ b/grub-core/fs/archelp.c
@@ -0,0 +1,301 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2007,2008,2009,2013 Free Software Foundation, Inc.
+ *
+ * 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 <grub/archelp.h>
+#include <grub/err.h>
+#include <grub/fs.h>
+#include <grub/disk.h>
+#include <grub/dl.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static inline void
+canonicalize (char *name)
+{
+ char *iptr, *optr;
+ for (iptr = name, optr = name; *iptr; )
+ {
+ while (*iptr == '/')
+ iptr++;
+ if (iptr[0] == '.' && (iptr[1] == '/' || iptr[1] == 0))
+ {
+ iptr++;
+ continue;
+ }
+ if (iptr[0] == '.' && iptr[1] == '.' && (iptr[2] == '/' || iptr[2] == 0))
+ {
+ iptr += 2;
+ if (optr == name)
+ continue;
+ for (optr -= 2; optr >= name && *optr != '/'; optr--);
+ optr++;
+ continue;
+ }
+ while (*iptr && *iptr != '/')
+ *optr++ = *iptr++;
+ if (*iptr)
+ *optr++ = *iptr++;
+ }
+ *optr = 0;
+}
+
+static grub_err_t
+handle_symlink (struct grub_archelp_data *data,
+ struct grub_archelp_ops *arcops,
+ const char *fn, char **name,
+ grub_uint32_t mode, int *restart)
+{
+ grub_size_t flen;
+ char *target;
+ char *ptr;
+ char *lastslash;
+ grub_size_t prefixlen;
+ char *rest;
+ char *linktarget;
+ grub_size_t linktarget_len;
+
+ *restart = 0;
+
+ if ((mode & GRUB_ARCHELP_ATTR_TYPE) != GRUB_ARCHELP_ATTR_LNK
+ || !arcops->get_link_target)
+ return GRUB_ERR_NONE;
+ flen = grub_strlen (fn);
+ if (grub_memcmp (*name, fn, flen) != 0
+ || ((*name)[flen] != 0 && (*name)[flen] != '/'))
+ return GRUB_ERR_NONE;
+ rest = *name + flen;
+ lastslash = rest;
+ if (*rest)
+ rest++;
+ while (lastslash >= *name && *lastslash != '/')
+ lastslash--;
+ if (lastslash >= *name)
+ prefixlen = lastslash - *name;
+ else
+ prefixlen = 0;
+
+ if (prefixlen)
+ prefixlen++;
+
+ linktarget = arcops->get_link_target (data);
+ if (!linktarget)
+ return grub_errno;
+ if (linktarget[0] == '\0')
+ return GRUB_ERR_NONE;
+ linktarget_len = grub_strlen (linktarget);
+ target = grub_malloc (linktarget_len + grub_strlen (*name) + 2);
+ if (!target)
+ return grub_errno;
+
+ grub_strcpy (target + prefixlen, linktarget);
+ grub_free (linktarget);
+ if (target[prefixlen] == '/')
+ {
+ ptr = grub_stpcpy (target, target + prefixlen);
+ ptr = grub_stpcpy (ptr, rest);
+ *ptr = 0;
+ grub_dprintf ("archelp", "symlink redirected %s to %s\n",
+ *name, target);
+ grub_free (*name);
+
+ canonicalize (target);
+ *name = target;
+ *restart = 1;
+ return GRUB_ERR_NONE;
+ }
+ if (prefixlen)
+ {
+ grub_memcpy (target, *name, prefixlen);
+ target[prefixlen-1] = '/';
+ }
+ grub_strcpy (target + prefixlen + linktarget_len, rest);
+ grub_dprintf ("archelp", "symlink redirected %s to %s\n",
+ *name, target);
+ grub_free (*name);
+ canonicalize (target);
+ *name = target;
+ *restart = 1;
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_archelp_dir (struct grub_archelp_data *data,
+ struct grub_archelp_ops *arcops,
+ const char *path_in,
+ grub_fs_dir_hook_t hook, void *hook_data)
+{
+ char *prev, *name, *path, *ptr;
+ grub_size_t len;
+ int symlinknest = 0;
+
+ path = grub_strdup (path_in + 1);
+ if (!path)
+ return grub_errno;
+ canonicalize (path);
+ for (ptr = path + grub_strlen (path) - 1; ptr >= path && *ptr == '/'; ptr--)
+ *ptr = 0;
+
+ prev = 0;
+
+ len = grub_strlen (path);
+ while (1)
+ {
+ grub_int32_t mtime;
+ grub_uint32_t mode;
+ grub_err_t err;
+
+ if (arcops->find_file (data, &name, &mtime, &mode))
+ goto fail;
+
+ if (mode == GRUB_ARCHELP_ATTR_END)
+ break;
+
+ canonicalize (name);
+
+ if (grub_memcmp (path, name, len) == 0
+ && (name[len] == 0 || name[len] == '/' || len == 0))
+ {
+ char *p, *n;
+
+ n = name + len;
+ while (*n == '/')
+ n++;
+
+ p = grub_strchr (n, '/');
+ if (p)
+ *p = 0;
+
+ if (((!prev) || (grub_strcmp (prev, name) != 0)) && *n != 0)
+ {
+ struct grub_dirhook_info info;
+ grub_memset (&info, 0, sizeof (info));
+ info.dir = (p != NULL) || ((mode & GRUB_ARCHELP_ATTR_TYPE)
+ == GRUB_ARCHELP_ATTR_DIR);
+ if (!(mode & GRUB_ARCHELP_ATTR_NOTIME))
+ {
+ info.mtime = mtime;
+ info.mtimeset = 1;
+ }
+ if (hook (n, &info, hook_data))
+ {
+ grub_free (name);
+ goto fail;
+ }
+ grub_free (prev);
+ prev = name;
+ }
+ else
+ {
+ int restart = 0;
+ err = handle_symlink (data, arcops, name,
+ &path, mode, &restart);
+ grub_free (name);
+ if (err)
+ goto fail;
+ if (restart)
+ {
+ len = grub_strlen (path);
+ if (++symlinknest == 8)
+ {
+ grub_error (GRUB_ERR_SYMLINK_LOOP,
+ N_("too deep nesting of symlinks"));
+ goto fail;
+ }
+ arcops->rewind (data);
+ }
+ }
+ }
+ else
+ grub_free (name);
+ }
+
+fail:
+
+ grub_free (path);
+ grub_free (prev);
+
+ return grub_errno;
+}
+
+grub_err_t
+grub_archelp_open (struct grub_archelp_data *data,
+ struct grub_archelp_ops *arcops,
+ const char *name_in)
+{
+ char *fn;
+ char *name = grub_strdup (name_in + 1);
+ int symlinknest = 0;
+
+ if (!name)
+ return grub_errno;
+
+ canonicalize (name);
+
+ while (1)
+ {
+ grub_uint32_t mode;
+ grub_int32_t mtime;
+ int restart;
+
+ if (arcops->find_file (data, &fn, &mtime, &mode))
+ goto fail;
+
+ if (mode == GRUB_ARCHELP_ATTR_END)
+ {
+ grub_error (GRUB_ERR_FILE_NOT_FOUND, N_("file `%s' not found"), name_in);
+ break;
+ }
+
+ canonicalize (fn);
+
+ if (handle_symlink (data, arcops, fn, &name, mode, &restart))
+ {
+ grub_free (fn);
+ goto fail;
+ }
+
+ if (restart)
+ {
+ arcops->rewind (data);
+ if (++symlinknest == 8)
+ {
+ grub_error (GRUB_ERR_SYMLINK_LOOP,
+ N_("too deep nesting of symlinks"));
+ goto fail;
+ }
+ goto no_match;
+ }
+
+ if (grub_strcmp (name, fn) != 0)
+ goto no_match;
+
+ grub_free (fn);
+ grub_free (name);
+
+ return GRUB_ERR_NONE;
+
+ no_match:
+
+ grub_free (fn);
+ }
+
+fail:
+ grub_free (name);
+
+ return grub_errno;
+}
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