From: "M. Mohan Kumar" <mo...@in.ibm.com> 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 | 78 ++++++++++++++++++++++++++++++++++++++++++-- 3 files changed, 97 insertions(+), 12 deletions(-) diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c index 63de410..f5b3abc 100644 --- a/hw/9pfs/virtio-9p-chroot.c +++ b/hw/9pfs/virtio-9p-chroot.c @@ -91,13 +91,26 @@ 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 caller. 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 a817bcf..326238d 100644 --- a/hw/9pfs/virtio-9p-chroot.h +++ b/hw/9pfs/virtio-9p-chroot.h @@ -35,6 +35,6 @@ 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 1b6c323..2ae4317 100644 --- a/hw/9pfs/virtio-9p-local.c +++ b/hw/9pfs/virtio-9p-local.c @@ -14,6 +14,9 @@ #include "hw/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> @@ -21,6 +24,63 @@ #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, V9fsPath *fs_path, struct stat *stbuf) { int err; @@ -153,7 +213,11 @@ static int local_open(FsContext *ctx, V9fsPath *fs_path, int flags) char buffer[PATH_MAX]; char *path = fs_path->data; - return open(rpath(ctx, path, buffer), flags); + if (ctx->fs_sm == SM_PASSTHROUGH) { + return passthrough_request(ctx, NULL, path, flags, NULL, T_OPEN); + } else { + return open(rpath(ctx, path, buffer), flags); + } } static DIR *local_opendir(FsContext *ctx, V9fsPath *fs_path) @@ -161,7 +225,16 @@ static DIR *local_opendir(FsContext *ctx, V9fsPath *fs_path) char buffer[PATH_MAX]; char *path = fs_path->data; - return opendir(rpath(ctx, path, buffer)); + if (ctx->fs_sm == SM_PASSTHROUGH) { + int fd; + fd = passthrough_request(ctx, NULL, path, O_DIRECTORY, NULL, T_OPEN); + if (fd < 0) { + return NULL; + } + return fdopendir(fd); + } else { + return opendir(rpath(ctx, path, buffer)); + } } static void local_rewinddir(FsContext *ctx, DIR *dir) @@ -407,7 +480,6 @@ out: return err; } - static int local_symlink(FsContext *fs_ctx, const char *oldpath, V9fsPath *dir_path, const char *name, FsCred *credp) { -- 1.7.5.4