Add both server and client side interfaces to create special files (directory, device nodes, links and symbolic links)
Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com> --- hw/9pfs/virtio-9p-chroot.c | 84 ++++++++++++++++++++++++++- hw/9pfs/virtio-9p-chroot.h | 2 + hw/9pfs/virtio-9p-local.c | 141 ++++++++++++++++++++++++++++++++++---------- 3 files changed, 195 insertions(+), 32 deletions(-) diff --git a/hw/9pfs/virtio-9p-chroot.c b/hw/9pfs/virtio-9p-chroot.c index e7f85e2..92a4917 100644 --- a/hw/9pfs/virtio-9p-chroot.c +++ b/hw/9pfs/virtio-9p-chroot.c @@ -193,6 +193,29 @@ static void chroot_do_open(V9fsFileObjectRequest *request, FdInfo *fd_info) } } +int v9fs_create_special(FsContext *fs_ctx, + V9fsFileObjectRequest *request, int *error) +{ + int retval; + + pthread_mutex_lock(&fs_ctx->chroot_mutex); + + *error = 0; + v9fs_write_request(fs_ctx->chroot_socket, request); + retval = qemu_read_full(fs_ctx->chroot_socket, error, sizeof(*error)); + if (retval != sizeof(*error)) { + error_report("reading from socket failed: %s", strerror(errno)); + exit(1); + } + + pthread_mutex_unlock(&fs_ctx->chroot_mutex); + if (*error) { + return -1; + } else { + return 0; + } +} + /* * Helper routine to create a file and return the file descriptor and * error status in FdInfo structure. @@ -229,6 +252,56 @@ unset_uid: setfsuid(cur_uid); } +/* + * Create directory, symbolic link, link, device node and regular files + * Similar to create, but it does not return the fd of created object + * Returns 0 on success, returns errno on failure + */ +static int chroot_do_create_special(V9fsFileObjectRequest *request) +{ + int cur_uid, cur_gid; + int retval, error; + + cur_uid = geteuid(); + cur_gid = getegid(); + + if (setfsuid(request->data.uid) < 0) { + return errno; + } + if (setfsgid(request->data.gid) < 0) { + error = errno; + goto unset_uid; + } + + switch (request->data.type) { + case T_MKDIR: + retval = mkdir(request->path.path, request->data.mode); + break; + case T_SYMLINK: + retval = symlink(request->path.old_path, request->path.path); + break; + case T_LINK: + retval = link(request->path.old_path, request->path.path); + break; + default: + retval = mknod(request->path.path, request->data.mode, + request->data.dev); + break; + } + + if (retval < 0) { + error = errno; + } else { + error = 0; + } + + setfsgid(cur_gid); +unset_uid: + setfsuid(cur_uid); + + return error; +} + static int chroot_daemonize(int chroot_sock) { sigset_t sigset; @@ -263,7 +336,7 @@ static int chroot_daemonize(int chroot_sock) */ int v9fs_chroot(FsContext *fs_ctx) { - int fd_pair[2], pid, chroot_sock, error; + int fd_pair[2], pid, chroot_sock, error, retval; V9fsFileObjectRequest request; FdInfo fd_info; @@ -318,6 +391,15 @@ int v9fs_chroot(FsContext *fs_ctx) error = -2; } break; + case T_MKDIR: + case T_SYMLINK: + case T_LINK: + case T_MKNOD: + retval = chroot_do_create_special(&request); + if (qemu_write_full(chroot_sock, &retval, sizeof(retval)) < 0) { + error = -2; + } + break; default: break; } diff --git a/hw/9pfs/virtio-9p-chroot.h b/hw/9pfs/virtio-9p-chroot.h index f5a2ca0..9a0ba88 100644 --- a/hw/9pfs/virtio-9p-chroot.h +++ b/hw/9pfs/virtio-9p-chroot.h @@ -36,5 +36,7 @@ typedef struct V9fsFileObjectRequest int v9fs_chroot(FsContext *fs_ctx); int v9fs_request(FsContext *fs_ctx, V9fsFileObjectRequest *or, int *error); +int v9fs_create_special(FsContext *fs_ctx, + V9fsFileObjectRequest *request, 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 7f39b40..08fd67f 100644 --- a/hw/9pfs/virtio-9p-local.c +++ b/hw/9pfs/virtio-9p-local.c @@ -69,6 +69,78 @@ static int __create(FsContext *fs_ctx, const char *path, int flags, return fd; } +static int __mknod(FsContext *fs_ctx, const char *path, FsCred *credp) +{ + V9fsFileObjectRequest request; + int retval, error = 0; + + fill_request(&request, path, credp); + request.data.type = T_MKNOD; + + retval = v9fs_create_special(fs_ctx, &request, &error); + if (retval < 0) { + errno = error; + } + return retval; +} + +static int __mkdir(FsContext *fs_ctx, const char *path, FsCred *credp) +{ + V9fsFileObjectRequest request; + int retval, error = 0; + + fill_request(&request, path, credp); + request.data.type = T_MKDIR; + + retval = v9fs_create_special(fs_ctx, &request, &error); + if (retval > 0) { + errno = error; + } + qemu_free(request.path.path); + return retval; +} + +static int __symlink(FsContext *fs_ctx, const char *oldpath, + const char *newpath, FsCred *credp) +{ + V9fsFileObjectRequest request; + int retval, error = 0; + + fill_request(&request, newpath, credp); + request.data.type = T_SYMLINK; + request.data.oldpath_len = strlen(oldpath); + request.path.old_path = qemu_strdup(oldpath); + + retval = v9fs_create_special(fs_ctx, &request, &error); + if (retval > 0) { + errno = error; + return 0; + } + qemu_free(request.path.old_path); + qemu_free(request.path.path); + return retval; +} + +static int __link(FsContext *fs_ctx, const char *oldpath, + const char *newpath) +{ + V9fsFileObjectRequest request; + int retval, error = 0; + + fill_request(&request, newpath, NULL); + request.data.type = T_LINK; + request.data.oldpath_len = strlen(oldpath); + request.path.old_path = qemu_strdup(oldpath); + retval = v9fs_create_special(fs_ctx, &request, &error); + if (retval > 0) { + errno = error; + return 0; + } + qemu_free(request.path.old_path); + qemu_free(request.path.path); + return retval; +} + static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf) { int err; @@ -286,8 +358,7 @@ static int local_mknod(FsContext *fs_ctx, const char *path, FsCred *credp) serrno = errno; goto err_end; } - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) || - (fs_ctx->fs_sm == SM_NONE)) { + } else if (fs_ctx->fs_sm == SM_NONE) { err = mknod(rpath(fs_ctx, path), credp->fc_mode, credp->fc_rdev); if (err == -1) { return err; @@ -297,6 +368,12 @@ static int local_mknod(FsContext *fs_ctx, const char *path, FsCred *credp) serrno = errno; goto err_end; } + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) { + err = __mknod(fs_ctx, path, credp); + if (err < 0) { + serrno = errno; + goto err_end; + } } return err; @@ -323,8 +400,7 @@ static int local_mkdir(FsContext *fs_ctx, const char *path, FsCred *credp) serrno = errno; goto err_end; } - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) || - (fs_ctx->fs_sm == SM_NONE)) { + } else if (fs_ctx->fs_sm == SM_NONE) { err = mkdir(rpath(fs_ctx, path), credp->fc_mode); if (err == -1) { return err; @@ -334,6 +410,12 @@ static int local_mkdir(FsContext *fs_ctx, const char *path, FsCred *credp) serrno = errno; goto err_end; } + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) { + err = __mkdir(fs_ctx, path, credp); + if (err < 0) { + serrno = errno; + goto err_end; + } } return err; @@ -451,23 +533,18 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath, serrno = errno; goto err_end; } - } else if ((fs_ctx->fs_sm == SM_PASSTHROUGH) || - (fs_ctx->fs_sm == SM_NONE)) { + } else if (fs_ctx->fs_sm == SM_NONE) { err = symlink(oldpath, rpath(fs_ctx, newpath)); if (err) { return err; } err = lchown(rpath(fs_ctx, newpath), credp->fc_uid, credp->fc_gid); - if (err == -1) { - /* - * If we fail to change ownership and if we are - * using security model none. Ignore the error - */ - if (fs_ctx->fs_sm != SM_NONE) { - serrno = errno; - goto err_end; - } else - err = 0; + err = 0; + } else if (fs_ctx->fs_sm == SM_PASSTHROUGH) { + err = __symlink(fs_ctx, oldpath, newpath, credp); + if (err < 0) { + serrno = errno; + goto err_end; } } return err; @@ -478,24 +555,26 @@ err_end: return err; } -static int local_link(FsContext *ctx, const char *oldpath, const char *newpath) +static int local_link(FsContext *fs_ctx, const char *oldpath, + const char *newpath) { - char *tmp = qemu_strdup(rpath(ctx, oldpath)); int err, serrno = 0; - if (tmp == NULL) { - return -ENOMEM; - } - - err = link(tmp, rpath(ctx, newpath)); - if (err == -1) { - serrno = errno; - } - - qemu_free(tmp); - - if (err == -1) { - errno = serrno; + if (fs_ctx->fs_sm == SM_PASSTHROUGH) { + err = __link(fs_ctx, oldpath, newpath); + if (err < 0) { + serrno = errno; + } + } else { + char *tmp = qemu_strdup(rpath(fs_ctx, oldpath)); + if (tmp == NULL) { + return -ENOMEM; + } + err = link(tmp, rpath(fs_ctx, newpath)); + if (err == -1) { + serrno = errno; + } + qemu_free(tmp); } return err; -- 1.7.3.4