This patch adds both chroot worker and qemu side support to open a file/
directory in the chroot environment
Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com>
---
hw/9pfs/virtio-9p-chroot.c | 29 +++++++++++----
hw/9pfs/virtio-9p-chroot.h | 2 +-
hw/9pfs/virtio-9p-local.c | 80 +++++++++++++++++++++++++++++++++++++++++--
3 files changed, 98 insertions(+), 13 deletions(-)
diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c
index 4aa3b43..8d41087 100644
--- a/hw/9pfs/virtio-9p-chroot.c
+++ b/hw/9pfs/virtio-9p-chroot.c
@@ -80,13 +80,26 @@ static int v9fs_write_request(int sockfd,
V9fsFileObjectRequest *request)
return 0;
}
-/*
- * This patch adds v9fs_receivefd and v9fs_write_request functions,
- * but there is no callers. To avoid compiler warning message,
- * refer these two functions
- */
-void chroot_dummy(void)
+/* Return opened file descriptor on success or -errno on error */
+int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *request)
{
- (void)v9fs_receivefd;
- (void)v9fs_write_request;
+ int fd, sock_error;
+ qemu_mutex_lock(&fs_ctx->chroot_mutex);
+ if (fs_ctx->chroot_socket == -1) {
+ goto error;
+ }
+ if (v9fs_write_request(fs_ctx->chroot_socket, request) < 0) {
+ goto error;
+ }
+ fd = v9fs_receivefd(fs_ctx->chroot_socket, &sock_error);
+ if (fd < 0 && sock_error) {
+ goto error;
+ }
+ qemu_mutex_unlock(&fs_ctx->chroot_mutex);
+ return fd;
+error:
+ close(fs_ctx->chroot_socket);
+ fs_ctx->chroot_socket = -1;
+ qemu_mutex_unlock(&fs_ctx->chroot_mutex);
+ return -EIO;
}
diff --git a/hw/9pfs/virtio-9p-chroot.h b/hw/9pfs/virtio-9p-chroot.h
index f8c6d77..ac94e59 100644
--- a/hw/9pfs/virtio-9p-chroot.h
+++ b/hw/9pfs/virtio-9p-chroot.h
@@ -33,6 +33,6 @@ typedef struct V9fsFileObjectRequest
} V9fsFileObjectRequest;
int v9fs_chroot(FsContext *fs_ctx);
-void chroot_dummy(void);
+int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *or);
#endif /* _QEMU_VIRTIO_9P_CHROOT_H */
diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index 43ff37c..2601f77 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -13,6 +13,9 @@
#include "virtio.h"
#include "virtio-9p.h"
#include "virtio-9p-xattr.h"
+#include "qemu_socket.h"
+#include "fsdev/qemu-fsdev.h"
+#include "virtio-9p-chroot.h"
#include <arpa/inet.h>
#include <pwd.h>
#include <grp.h>
@@ -20,6 +23,62 @@
#include <sys/un.h>
#include <attr/xattr.h>
+/* Helper routine to fill V9fsFileObjectRequest structure */
+static int fill_fileobjectrequest(V9fsFileObjectRequest *request,
+ const char *oldpath, const char *path, int flags,
+ FsCred *credp, int type)
+{
+ if (oldpath && strlen(oldpath) >= PATH_MAX) {
+ return -ENAMETOOLONG;
+ }
+ /* path can't be NULL */
+ if (!path) {
+ return -EFAULT;
+ }
+
+ if (strlen(path) >= PATH_MAX) {
+ return -ENAMETOOLONG;
+ }
+ strcpy(request->path.path, path);
+ if (oldpath) {
+ strcpy(request->path.old_path, oldpath);
+ } else {
+ request->path.old_path[0] = '\0';
+ }
+
+ memset(&request->data, 0, sizeof(request->data));
+ if (credp) {
+ request->data.mode = credp->fc_mode;
+ request->data.uid = credp->fc_uid;
+ request->data.gid = credp->fc_gid;
+ request->data.dev = credp->fc_rdev;
+ }
+
+ request->data.flags = flags;
+ request->data.type = type;
+ return 0;
+}
+
+static int passthrough_request(FsContext *fs_ctx, const char *old_path,
+ const char *path, int flags, FsCred *credp, int type)
+{
+ V9fsFileObjectRequest request;
+ int retval;
+
+ retval = fill_fileobjectrequest(&request, old_path, path, flags, credp,
+ type);
+ if (retval < 0) {
+ errno = -retval;
+ return -1;
+ }
+
+ retval = v9fs_request(fs_ctx, &request);
+ if (retval < 0) {
+ errno = -retval;
+ retval = -1;
+ }
+ return retval;
+}
static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf)
{
@@ -138,14 +197,27 @@ static int local_closedir(FsContext *ctx, DIR *dir)
return closedir(dir);
}
-static int local_open(FsContext *ctx, const char *path, int flags)
+static int local_open(FsContext *fs_ctx, const char *path, int flags)
{
- return open(rpath(ctx, path), flags);
+ if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
+ return passthrough_request(fs_ctx, NULL, path, flags, NULL, T_OPEN);
+ } else {
+ return open(rpath(fs_ctx, path), flags);
+ }
}
-static DIR *local_opendir(FsContext *ctx, const char *path)
+static DIR *local_opendir(FsContext *fs_ctx, const char *path)
{
- return opendir(rpath(ctx, path));
+ if (fs_ctx->fs_sm == SM_PASSTHROUGH) {
+ int fd;
+ fd = passthrough_request(fs_ctx, NULL, path, O_DIRECTORY, NULL,
T_OPEN);
+ if (fd < 0) {
+ return NULL;
+ }
+ return fdopendir(fd);
+ } else {
+ return opendir(rpath(fs_ctx, path));
+ }
}
static void local_rewinddir(FsContext *ctx, DIR *dir)
--
1.7.4
