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 | 28 ++++++++++++++----- hw/9pfs/virtio-9p-chroot.h | 2 +- hw/9pfs/virtio-9p-local.c | 62 +++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 79 insertions(+), 13 deletions(-) diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c index 4aa3b43..0c91db6 100644 --- a/hw/9pfs/virtio-9p-chroot.c +++ b/hw/9pfs/virtio-9p-chroot.c @@ -80,13 +80,25 @@ 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_ioerror) { + fd = -EIO; + goto unlock; + } + if (v9fs_write_request(fs_ctx->chroot_socket, request) < 0) { + fs_ctx->chroot_ioerror = 1; + fd = -EIO; + goto unlock; + } + fd = v9fs_receivefd(fs_ctx->chroot_socket, &sock_error); + if (fd < 0 && sock_error) { + fs_ctx->chroot_ioerror = 1; + } +unlock: + qemu_mutex_unlock(&fs_ctx->chroot_mutex); + return fd; } diff --git a/hw/9pfs/virtio-9p-chroot.h b/hw/9pfs/virtio-9p-chroot.h index 0c020f8..6f676e9 100644 --- a/hw/9pfs/virtio-9p-chroot.h +++ b/hw/9pfs/virtio-9p-chroot.h @@ -39,6 +39,6 @@ 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 0a015de..8c187d7 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 +23,44 @@ #include <sys/un.h> #include <attr/xattr.h> +/* Helper routine to fill V9fsFileObjectRequest structure */ +static int fill_fileobjectrequest(V9fsFileObjectRequest *request, + const char *path, FsCred *credp) +{ + if (strlen(path) >= PATH_MAX) { + return -ENAMETOOLONG; + } + memset(request, 0, sizeof(*request)); + request->data.path_len = strlen(path); + strcpy(request->path.path, path); + 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; + } + return 0; +} + +static int passthrough_open(FsContext *fs_ctx, const char *path, int flags) +{ + V9fsFileObjectRequest request; + int fd; + + fd = fill_fileobjectrequest(&request, path, NULL); + if (fd < 0) { + errno = -fd; + return -1; + } + request.data.flags = flags; + request.data.type = T_OPEN; + fd = v9fs_request(fs_ctx, &request); + if (fd < 0) { + errno = -fd; + fd = -1; + } + return fd; +} static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf) { @@ -138,14 +179,27 @@ 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_open(fs_ctx, path, flags); + } 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_open(fs_ctx, path, O_DIRECTORY); + if (fd < 0) { + return NULL; + } + return fdopendir(fd); + } else { + return opendir(rpath(fs_ctx, path)); + } } static void local_rewinddir(FsContext *ctx, DIR *dir) -- 1.7.3.4