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[Qemu-devel] [PULL v2 09/11] 9pfs: local: resolve special directories in
From: |
Greg Kurz |
Subject: |
[Qemu-devel] [PULL v2 09/11] 9pfs: local: resolve special directories in paths |
Date: |
Tue, 30 May 2017 15:40:38 +0200 |
When using the mapped-file security mode, the creds of a path /foo/bar
are stored in the /foo/.virtfs_metadata/bar file. This is okay for all
paths unless they end with '.' or '..', because we cannot create the
corresponding file in the metadata directory.
This patch ensures that '.' and '..' are resolved in all paths.
The core code only passes path elements (no '/') to the backend, with
the notable exception of the '/' path, which refers to the virtfs root.
This patch preserves the current behavior of converting it to '.' so
that it can be passed to "*at()" syscalls ('/' would mean the host root).
Signed-off-by: Greg Kurz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
hw/9pfs/9p-local.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 226234d38642..68e92652ed73 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1134,14 +1134,32 @@ static int local_name_to_path(FsContext *ctx, V9fsPath
*dir_path,
}
if (dir_path) {
- v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
- } else if (strcmp(name, "/")) {
- v9fs_path_sprintf(target, "%s", name);
+ if (!strcmp(name, ".")) {
+ /* "." relative to "foo/bar" is "foo/bar" */
+ v9fs_path_copy(target, dir_path);
+ } else if (!strcmp(name, "..")) {
+ if (!strcmp(dir_path->data, ".")) {
+ /* ".." relative to the root is "." */
+ v9fs_path_sprintf(target, ".");
+ } else {
+ char *tmp = g_path_get_dirname(dir_path->data);
+ /* Symbolic links are resolved by the client. We can assume
+ * that ".." relative to "foo/bar" is equivalent to "foo"
+ */
+ v9fs_path_sprintf(target, "%s", tmp);
+ g_free(tmp);
+ }
+ } else {
+ assert(!strchr(name, '/'));
+ v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
+ }
+ } else if (!strcmp(name, "/") || !strcmp(name, ".") ||
+ !strcmp(name, "..")) {
+ /* This is the root fid */
+ v9fs_path_sprintf(target, ".");
} else {
- /* We want the path of the export root to be relative, otherwise
- * "*at()" syscalls would treat it as "/" in the host.
- */
- v9fs_path_sprintf(target, "%s", ".");
+ assert(!strchr(name, '/'));
+ v9fs_path_sprintf(target, "./%s", name);
}
return 0;
}
--
2.7.5
- [Qemu-devel] [PULL v2 00/11] 9pfs patches for 2.10 20170530, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 01/11] virtio-9p/xen-9p: move 9p specific bits to core 9p code, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 05/11] fsdev: fix virtfs-proxy-helper cwd, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 02/11] fsdev: don't allow unknown format in marshal/unmarshal, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 04/11] 9pfs: local: fix unlink of alien files in mapped-file mode, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 07/11] util: drop old utimensat() compat code, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 03/11] 9pfs: drop pdu_push_and_notify(), Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 06/11] 9pfs: assume utimensat() and futimens() are present, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 11/11] 9pfs: local: metadata file for the VirtFS root, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 10/11] 9pfs: local: simplify file opening, Greg Kurz, 2017/05/30
- [Qemu-devel] [PULL v2 09/11] 9pfs: local: resolve special directories in paths,
Greg Kurz <=
- [Qemu-devel] [PULL v2 08/11] 9pfs: check return value of v9fs_co_name_to_path(), Greg Kurz, 2017/05/30