nixpkgs/pkgs/applications/virtualization/qemu/force-uid0-on-9p.patch
aszlig 38ea64e867
qemu_test: Make chown() calls to the store a no-op
The "misc" NixOS test is using Nix to query the store and it tries to
change the ownership of it while doing so.

This fails if Nix is not in a seccomp-sandboxed userid namespace, so
let's make chown() a no-op when applied to store paths.

Fixes the misc test (and possibly future tests) on older Nix versions.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
2016-12-16 13:06:25 +01:00

78 lines
2.6 KiB
Diff

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 3f271fc..dc273f4 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -45,6 +45,23 @@
#define VIRTFS_META_DIR ".virtfs_metadata"
+static int is_in_store_path(const char *path)
+{
+ static char *store_path = NULL;
+ int store_path_len = -1;
+
+ if (store_path_len == -1) {
+ if ((store_path = getenv("NIX_STORE")) != NULL)
+ store_path_len = strlen(store_path);
+ else
+ store_path_len = 0;
+ }
+
+ if (store_path_len > 0)
+ return strncmp(path, store_path, strlen(store_path)) == 0;
+ return 0;
+}
+
static char *local_mapped_attr_path(FsContext *ctx, const char *path)
{
int dirlen;
@@ -128,6 +145,8 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
if (err) {
goto err_out;
}
+ stbuf->st_uid = 0;
+ stbuf->st_gid = 0;
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
/* Actual credentials are part of extended attrs */
uid_t tmp_uid;
@@ -462,6 +481,11 @@ static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs,
return ret;
}
+static inline int maybe_chmod(const char *path, mode_t mode)
+{
+ return is_in_store_path(path) ? 0 : chmod(path, mode);
+}
+
static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
{
char *buffer;
@@ -477,7 +501,7 @@ static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
} else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
buffer = rpath(fs_ctx, path);
- ret = chmod(buffer, credp->fc_mode);
+ ret = maybe_chmod(buffer, credp->fc_mode);
g_free(buffer);
}
return ret;
@@ -621,6 +645,8 @@ static int local_fstat(FsContext *fs_ctx, int fid_type,
if (err) {
return err;
}
+ stbuf->st_uid = 0;
+ stbuf->st_gid = 0;
if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
/* Actual credentials are part of extended attrs */
uid_t tmp_uid;
@@ -916,7 +942,8 @@ static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp)
(fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) ||
(fs_ctx->export_flags & V9FS_SM_NONE)) {
buffer = rpath(fs_ctx, path);
- ret = lchown(buffer, credp->fc_uid, credp->fc_gid);
+ ret = is_in_store_path(buffer)
+ ? 0 : lchown(buffer, credp->fc_uid, credp->fc_gid);
g_free(buffer);
} else if (fs_ctx->export_flags & V9FS_SM_MAPPED) {
buffer = rpath(fs_ctx, path);