Fixes; write --{no,}rpfix docs; enable --rpfix capture by default

[wimlib] / src / symlink.c

diff --git a/src/symlink.c b/src/symlink.c
index 587b71cb8f07f5c31b802b53df1cdda71c398ff7..ea92a2df40f76253ef5367ae202906c2a44b9040 100644 (file)
--- a/src/symlink.c
+++ b/src/symlink.c
@@ -34,6 +34,10 @@
 
 #include <sys/stat.h>
 
+#ifdef HAVE_ALLOCA_H
+#  include <alloca.h>
+#endif
+
 /*
  * Find the symlink target of a symbolic link or junction point in the WIM.
  *
@@ -77,7 +81,8 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
                header_size = 12;
                p += 4;
        }
-       if (header_size + substitute_name_offset + substitute_name_len > resource_len)
+       if (header_size +
+           substitute_name_offset + substitute_name_len > resource_len)
                return -EIO;
 
        ret = utf16le_to_tstr((const utf16lechar*)(p + substitute_name_offset),
@@ -86,11 +91,6 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
        if (ret)
                return -errno;
 
-       if (link_target_len + 1 > buf_len) {
-               ret = -ENAMETOOLONG;
-               goto out;
-       }
-
        DEBUG("Interpeting substitute name \"%s\" (ReparseTag=0x%x)",
              link_target, reparse_tag);
        translate_slashes = true;
@@ -133,7 +133,7 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
                        /* "Relative" symlink, without drive letter */
                        ;
        } else {
-               ERROR("Invalid reparse point: \"%s\"", translated_target);
+               ERROR("Invalid reparse point substitute name: \"%s\"", translated_target);
                ret = -EIO;
                goto out;
        }
@@ -142,8 +142,14 @@ get_symlink_name(const void *resource, size_t resource_len, char *buf,
                for (size_t i = 0; i < link_target_len; i++)
                        if (translated_target[i] == '\\')
                                translated_target[i] = '/';
-       memcpy(buf, translated_target, link_target_len + 1);
-       ret = link_target_len;
+
+       if (link_target_len > buf_len) {
+               link_target_len = buf_len;
+               ret = -ENAMETOOLONG;
+       } else {
+               ret = link_target_len;
+       }
+       memcpy(buf, translated_target, link_target_len);
 out:
        FREE(link_target);
        return ret;
@@ -291,6 +297,7 @@ inode_readlink(const struct wim_inode *inode, char *buf, size_t buf_len,
 {
        const struct wim_lookup_table_entry *lte;
        int ret;
+       u8 *res_buf;
 
        wimlib_assert(inode_is_symlink(inode));
 
@@ -301,12 +308,12 @@ inode_readlink(const struct wim_inode *inode, char *buf, size_t buf_len,
        if (wim_resource_size(lte) > REPARSE_POINT_MAX_SIZE)
                return -EIO;
 
-       u8 res_buf[wim_resource_size(lte)];
+       res_buf = alloca(wim_resource_size(lte));
        ret = read_full_resource_into_buf(lte, res_buf, threadsafe);
        if (ret)
                return -EIO;
-       return get_symlink_name(res_buf, wim_resource_size(lte), buf,
-                               buf_len, inode->i_reparse_tag);
+       return get_symlink_name(res_buf, wim_resource_size(lte),
+                               buf, buf_len, inode->i_reparse_tag);
 }
 
 /*
@@ -406,7 +413,8 @@ unix_get_ino_and_dev(const char *path, u64 *ino_ret, u64 *dev_ret)
 #  define os_get_ino_and_dev unix_get_ino_and_dev
 #endif
 
-/* Fix up reparse points--- mostly shared between UNIX and Windows */
+/* Fix up absolute symbolic link targets--- mostly shared between UNIX and
+ * Windows */
 tchar *
 fixup_symlink(tchar *dest, u64 capture_root_ino, u64 capture_root_dev)
 {
@@ -433,6 +441,10 @@ fixup_symlink(tchar *dest, u64 capture_root_ino, u64 capture_root_dev)
                ret = os_get_ino_and_dev(dest, &ino, &dev);
                *p = save;
 
+               if (ret) /* stat() failed before we got to the capture root---
+                           assume the link points outside it. */
+                       return NULL;
+
                if (ino == capture_root_ino && dev == capture_root_dev) {
                        /* Link points inside capture root.  Return abbreviated
                         * path. */