This patch adds both server and client 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-clnt.c | 22 +++++++++++++--- hw/9pfs/virtio-9p-chroot-sv.c | 26 +++++++++++++++++++ hw/9pfs/virtio-9p-chroot.h | 2 +- hw/9pfs/virtio-9p-local.c | 53 ++++++++++++++++++++++++++++++++++++--- 4 files changed, 94 insertions(+), 9 deletions(-) diff --git a/hw/9pfs/virtio-9p-chroot-clnt.c b/hw/9pfs/virtio-9p-chroot-clnt.c index ac65f03..7f72add 100644 --- a/hw/9pfs/virtio-9p-chroot-clnt.c +++ b/hw/9pfs/virtio-9p-chroot-clnt.c @@ -88,9 +88,23 @@ static int v9fs_write_request(int sockfd, V9fsFileObjectRequest *request) return 0; } -void chroot_dummy(void) +/* Return opened file descriptor on success or -1 on error */ +int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *request, + int *error) { - (void)v9fs_receivefd; - (void)v9fs_write_request; + int fd; + qemu_mutex_lock(&fs_ctx->chroot_mutex); + if (fs_ctx->chroot_ioerror) { + *error = EIO; + fd = -1; + goto unlock; + } + v9fs_write_request(fs_ctx->chroot_socket, request); + fd = v9fs_receivefd(fs_ctx->chroot_socket, error); + if (fd == -EIO && *error == EIO) { + fs_ctx->chroot_ioerror = 1; + } +unlock: + qemu_mutex_unlock(&fs_ctx->chroot_mutex); + return fd; } - diff --git a/hw/9pfs/virtio-9p-chroot-sv.c b/hw/9pfs/virtio-9p-chroot-sv.c index 86d10cd..e9952b3 100644 --- a/hw/9pfs/virtio-9p-chroot-sv.c +++ b/hw/9pfs/virtio-9p-chroot-sv.c @@ -70,6 +70,21 @@ static int chroot_read_request(int sockfd, V9fsFileObjectRequest *request) return 0; } +/* + * Helper routine to open a file and return fd and error status in + * FdInfo structure + */ +static void chroot_do_open(V9fsFileObjectRequest *request, FdInfo *fd_info) +{ + fd_info->fi_fd = open(request->path.path, request->data.flags); + if (fd_info->fi_fd < 0) { + fd_info->fi_error = errno; + } else { + fd_info->fi_error = 0; + fd_info->fi_flags = FI_FDVALID; + } +} + static int chroot_daemonize(int chroot_sock) { sigset_t sigset; @@ -164,6 +179,17 @@ int v9fs_chroot(FsContext *fs_ctx) fd_info.fi_error = EIO; fd_info.fi_flags = FI_SOCKERR; chroot_sendfd(chroot_sock, &fd_info); + continue; + } + switch (request.data.type) { + case T_OPEN: + chroot_do_open(&request, &fd_info); + break; + default: + fd_info.fi_fd = 0; + fd_info.fi_error = EIO; + break; } + chroot_sendfd(chroot_sock, &fd_info); } } diff --git a/hw/9pfs/virtio-9p-chroot.h b/hw/9pfs/virtio-9p-chroot.h index 9122edc..057dcde 100644 --- a/hw/9pfs/virtio-9p-chroot.h +++ b/hw/9pfs/virtio-9p-chroot.h @@ -53,6 +53,6 @@ typedef struct V9fsFileObjectRequest } V9fsFileObjectRequest; int v9fs_chroot(FsContext *fs_ctx); -void chroot_dummy(void); +int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *or, int *error); #endif /* _QEMU_VIRTIO_9P_CHROOT_H */ diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c index 0a015de..bef0272 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 +23,35 @@ #include <sys/un.h> #include <attr/xattr.h> +/* Helper routine to fill V9fsFileObjectRequest structure */ +static void fill_request(V9fsFileObjectRequest *request, const char *path, + FsCred *credp) +{ + 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; + } +} + +static int passthrough_open(FsContext *fs_ctx, const char *path, int flags) +{ + V9fsFileObjectRequest request; + int fd, error = 0; + + fill_request(&request, path, NULL); + request.data.flags = flags; + request.data.type = T_OPEN; + fd = v9fs_request(fs_ctx, &request, &error); + if (fd < 0) { + errno = error; + } + return fd; +} static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf) { @@ -138,14 +170,27 @@ 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