From 4c793dda22213a7aba8e4d9a814e8f368a5f8bf7 Mon Sep 17 00:00:00 2001 From: "M. Mohan Kumar" Date: Wed, 14 Dec 2011 13:49:28 +0530 Subject: [PATCH 1/1] hw/9pfs: Add new proxy filesystem driver Add new proxy filesystem driver to add root privilege to qemu process. It needs a helper process to be started by root user. Following command line can be used to utilize proxy filesystem driver -virtfs proxy,id=,mount_tag=,socket_fd= Signed-off-by: M. Mohan Kumar Signed-off-by: Aneesh Kumar K.V --- Makefile.objs | 1 + fsdev/qemu-fsdev.c | 1 + fsdev/qemu-fsdev.h | 1 + hw/9pfs/virtio-9p-proxy.c | 388 ++++++++++++++++++++++++++++++++++++++ hw/9pfs/virtio-9p-proxy.h | 24 +++ qemu-config.c | 6 + vl.c | 6 +- 7 files changed, 426 insertions(+), 1 deletion(-) create mode 100644 hw/9pfs/virtio-9p-proxy.c create mode 100644 hw/9pfs/virtio-9p-proxy.h diff --git a/Makefile.objs b/Makefile.objs index 35cd64593..19d14598a 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -311,6 +311,7 @@ hw-obj-$(CONFIG_SOUND) += $(sound-obj-y) 9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o cofs.o codir.o cofile.o 9pfs-nested-$(CONFIG_VIRTFS) += coxattr.o virtio-9p-synth.o 9pfs-nested-$(CONFIG_OPEN_BY_HANDLE) += virtio-9p-handle.o +9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-proxy.o hw-obj-$(CONFIG_REALLY_VIRTFS) += $(addprefix 9pfs/, $(9pfs-nested-y)) $(addprefix 9pfs/, $(9pfs-nested-y)): QEMU_CFLAGS+=$(GLIB_CFLAGS) diff --git a/fsdev/qemu-fsdev.c b/fsdev/qemu-fsdev.c index 00f48ab44..e20202a4b 100644 --- a/fsdev/qemu-fsdev.c +++ b/fsdev/qemu-fsdev.c @@ -27,6 +27,7 @@ static FsDriverTable FsDrivers[] = { { .name = "handle", .ops = &handle_ops}, #endif { .name = "synth", .ops = &synth_ops}, + { .name = "proxy", .ops = &proxy_ops}, }; int qemu_fsdev_add(QemuOpts *opts) diff --git a/fsdev/qemu-fsdev.h b/fsdev/qemu-fsdev.h index 921452df2..1af1f545d 100644 --- a/fsdev/qemu-fsdev.h +++ b/fsdev/qemu-fsdev.h @@ -44,4 +44,5 @@ FsDriverEntry *get_fsdev_fsentry(char *id); extern FileOperations local_ops; extern FileOperations handle_ops; extern FileOperations synth_ops; +extern FileOperations proxy_ops; #endif diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c new file mode 100644 index 000000000..3e4dc68d3 --- /dev/null +++ b/hw/9pfs/virtio-9p-proxy.c @@ -0,0 +1,388 @@ +/* + * Virtio 9p Proxy callback + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * M. Mohan Kumar + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ +#include +#include +#include "hw/virtio.h" +#include "virtio-9p.h" +#include "fsdev/qemu-fsdev.h" +#include "virtio-9p-proxy.h" + +typedef struct V9fsProxy { + int sockfd; + QemuMutex mutex; + struct iovec iovec; +} V9fsProxy; + +static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) +{ + errno = EOPNOTSUPP; + return -1; +} + +static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path, + char *buf, size_t bufsz) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_close(FsContext *ctx, V9fsFidOpenState *fs) +{ + return close(fs->fd); +} + +static int proxy_closedir(FsContext *ctx, V9fsFidOpenState *fs) +{ + return closedir(fs->dir); +} + +static int proxy_open(FsContext *ctx, V9fsPath *fs_path, + int flags, V9fsFidOpenState *fs) +{ + fs->fd = -1; + return fs->fd; +} + +static int proxy_opendir(FsContext *ctx, + V9fsPath *fs_path, V9fsFidOpenState *fs) +{ + fs->dir = NULL; + errno = EOPNOTSUPP; + return -1; +} + +static void proxy_rewinddir(FsContext *ctx, V9fsFidOpenState *fs) +{ + return rewinddir(fs->dir); +} + +static off_t proxy_telldir(FsContext *ctx, V9fsFidOpenState *fs) +{ + return telldir(fs->dir); +} + +static int proxy_readdir_r(FsContext *ctx, V9fsFidOpenState *fs, + struct dirent *entry, + struct dirent **result) +{ + return readdir_r(fs->dir, entry, result); +} + +static void proxy_seekdir(FsContext *ctx, V9fsFidOpenState *fs, off_t off) +{ + return seekdir(fs->dir, off); +} + +static ssize_t proxy_preadv(FsContext *ctx, V9fsFidOpenState *fs, + const struct iovec *iov, + int iovcnt, off_t offset) +{ +#ifdef CONFIG_PREADV + return preadv(fs->fd, iov, iovcnt, offset); +#else + int err = lseek(fs->fd, offset, SEEK_SET); + if (err == -1) { + return err; + } else { + return readv(fs->fd, iov, iovcnt); + } +#endif +} + +static ssize_t proxy_pwritev(FsContext *ctx, V9fsFidOpenState *fs, + const struct iovec *iov, + int iovcnt, off_t offset) +{ + ssize_t ret; + +#ifdef CONFIG_PREADV + ret = pwritev(fs->fd, iov, iovcnt, offset); +#else + int err = lseek(fs->fd, offset, SEEK_SET); + if (err == -1) { + return err; + } else { + ret = writev(fs->fd, iov, iovcnt); + } +#endif +#ifdef CONFIG_SYNC_FILE_RANGE + if (ret > 0 && ctx->export_flags & V9FS_IMMEDIATE_WRITEOUT) { + /* + * Initiate a writeback. This is not a data integrity sync. + * We want to ensure that we don't leave dirty pages in the cache + * after write when writeout=immediate is sepcified. + */ + sync_file_range(fs->fd, offset, ret, + SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE); + } +#endif + return ret; +} + +static int proxy_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_mknod(FsContext *fs_ctx, V9fsPath *dir_path, + const char *name, FsCred *credp) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, + const char *name, FsCred *credp) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_fstat(FsContext *fs_ctx, int fid_type, + V9fsFidOpenState *fs, struct stat *stbuf) +{ + int fd; + + if (fid_type == P9_FID_DIR) { + fd = dirfd(fs->dir); + } else { + fd = fs->fd; + } + return fstat(fd, stbuf); +} + +static int proxy_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, + int flags, FsCred *credp, V9fsFidOpenState *fs) +{ + fs->fd = -1; + errno = EOPNOTSUPP; + return -1; +} + + +static int proxy_symlink(FsContext *fs_ctx, const char *oldpath, + V9fsPath *dir_path, const char *name, FsCred *credp) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_link(FsContext *ctx, V9fsPath *oldpath, + V9fsPath *dirpath, const char *name) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_rename(FsContext *ctx, const char *oldpath, + const char *newpath) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_utimensat(FsContext *s, V9fsPath *fs_path, + const struct timespec *buf) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_remove(FsContext *ctx, const char *path) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_fsync(FsContext *ctx, int fid_type, + V9fsFidOpenState *fs, int datasync) +{ + int fd; + + if (fid_type == P9_FID_DIR) { + fd = dirfd(fs->dir); + } else { + fd = fs->fd; + } + + if (datasync) { + return qemu_fdatasync(fd); + } else { + return fsync(fd); + } +} + +static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) +{ + errno = EOPNOTSUPP; + return -1; +} + +static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path, + const char *name, void *value, size_t size) +{ + errno = EOPNOTSUPP; + return -1; +} + +static ssize_t proxy_llistxattr(FsContext *ctx, V9fsPath *fs_path, + void *value, size_t size) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_lsetxattr(FsContext *ctx, V9fsPath *fs_path, const char *name, + void *value, size_t size, int flags) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_lremovexattr(FsContext *ctx, V9fsPath *fs_path, + const char *name) +{ + errno = EOPNOTSUPP; + return -1; +} + +static int proxy_name_to_path(FsContext *ctx, V9fsPath *dir_path, + const char *name, V9fsPath *target) +{ + if (dir_path) { + v9fs_string_sprintf((V9fsString *)target, "%s/%s", + dir_path->data, name); + } else { + v9fs_string_sprintf((V9fsString *)target, "%s", name); + } + /* Bump the size for including terminating NULL */ + target->size++; + return 0; +} + +static int proxy_renameat(FsContext *ctx, V9fsPath *olddir, + const char *old_name, V9fsPath *newdir, + const char *new_name) +{ + int ret; + V9fsString old_full_name, new_full_name; + + v9fs_string_init(&old_full_name); + v9fs_string_init(&new_full_name); + + v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name); + v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name); + + ret = proxy_rename(ctx, old_full_name.data, new_full_name.data); + v9fs_string_free(&old_full_name); + v9fs_string_free(&new_full_name); + return ret; +} + +static int proxy_unlinkat(FsContext *ctx, V9fsPath *dir, + const char *name, int flags) +{ + int ret; + V9fsString fullname; + v9fs_string_init(&fullname); + + v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name); + ret = proxy_remove(ctx, fullname.data); + v9fs_string_free(&fullname); + + return ret; +} + +static int proxy_parse_opts(QemuOpts *opts, struct FsDriverEntry *fs) +{ + const char *sock_fd = qemu_opt_get(opts, "sock_fd"); + + if (sock_fd) { + fprintf(stderr, "sock_fd option not specified\n"); + return -1; + } + fs->path = g_strdup(sock_fd); + return 0; +} + +static int proxy_init(FsContext *ctx) +{ + V9fsProxy *proxy = g_malloc(sizeof(V9fsProxy)); + int sock_id; + + sock_id = atoi(ctx->fs_root); + if (sock_id < 0) { + fprintf(stderr, "socket descriptor not initialized\n"); + return -1; + } + g_free(ctx->fs_root); + + proxy->iovec.iov_base = g_malloc(PROXY_MAX_IO_SZ + PROXY_HDR_SZ); + proxy->iovec.iov_len = PROXY_MAX_IO_SZ + PROXY_HDR_SZ; + ctx->private = proxy; + proxy->sockfd = sock_id; + qemu_mutex_init(&proxy->mutex); + + ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT; + return 0; +} + +FileOperations proxy_ops = { + .parse_opts = proxy_parse_opts, + .init = proxy_init, + .lstat = proxy_lstat, + .readlink = proxy_readlink, + .close = proxy_close, + .closedir = proxy_closedir, + .open = proxy_open, + .opendir = proxy_opendir, + .rewinddir = proxy_rewinddir, + .telldir = proxy_telldir, + .readdir_r = proxy_readdir_r, + .seekdir = proxy_seekdir, + .preadv = proxy_preadv, + .pwritev = proxy_pwritev, + .chmod = proxy_chmod, + .mknod = proxy_mknod, + .mkdir = proxy_mkdir, + .fstat = proxy_fstat, + .open2 = proxy_open2, + .symlink = proxy_symlink, + .link = proxy_link, + .truncate = proxy_truncate, + .rename = proxy_rename, + .chown = proxy_chown, + .utimensat = proxy_utimensat, + .remove = proxy_remove, + .fsync = proxy_fsync, + .statfs = proxy_statfs, + .lgetxattr = proxy_lgetxattr, + .llistxattr = proxy_llistxattr, + .lsetxattr = proxy_lsetxattr, + .lremovexattr = proxy_lremovexattr, + .name_to_path = proxy_name_to_path, + .renameat = proxy_renameat, + .unlinkat = proxy_unlinkat, +}; diff --git a/hw/9pfs/virtio-9p-proxy.h b/hw/9pfs/virtio-9p-proxy.h new file mode 100644 index 000000000..2d60b0ecd --- /dev/null +++ b/hw/9pfs/virtio-9p-proxy.h @@ -0,0 +1,24 @@ +/* + * Virtio 9p Proxy callback + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * M. Mohan Kumar + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + */ +#ifndef _QEMU_VIRTIO_9P_PROXY_H +#define _QEMU_VIRTIO_9P_PROXY_H + +#define PROXY_MAX_IO_SZ (64 * 1024) + +typedef struct { + uint32_t type; + uint32_t size; +} ProxyHeader; + +#define PROXY_HDR_SZ (sizeof(ProxyHeader)) + +#endif diff --git a/qemu-config.c b/qemu-config.c index 18f30204a..1bdc01ca6 100644 --- a/qemu-config.c +++ b/qemu-config.c @@ -211,6 +211,9 @@ QemuOptsList qemu_fsdev_opts = { }, { .name = "readonly", .type = QEMU_OPT_BOOL, + }, { + .name = "sock_fd", + .type = QEMU_OPT_NUMBER, }, { /*End of list */ } @@ -240,6 +243,9 @@ QemuOptsList qemu_virtfs_opts = { }, { .name = "readonly", .type = QEMU_OPT_BOOL, + }, { + .name = "sock_fd", + .type = QEMU_OPT_NUMBER, }, { /*End of list */ } diff --git a/vl.c b/vl.c index 47a8b0926..aaa2b9371 100644 --- a/vl.c +++ b/vl.c @@ -2661,7 +2661,7 @@ int main(int argc, char **argv, char **envp) case QEMU_OPTION_virtfs: { QemuOpts *fsdev; QemuOpts *device; - const char *writeout; + const char *writeout, *sock_fd; olist = qemu_find_opts("virtfs"); if (!olist) { @@ -2701,6 +2701,10 @@ int main(int argc, char **argv, char **envp) qemu_opt_set(fsdev, "path", qemu_opt_get(opts, "path")); qemu_opt_set(fsdev, "security_model", qemu_opt_get(opts, "security_model")); + sock_fd = qemu_opt_get(opts, "sock_fd"); + if (sock_fd) { + qemu_opt_set(fsdev, "sock_fd", sock_fd); + } qemu_opt_set_bool(fsdev, "readonly", qemu_opt_get_bool(opts, "readonly", 0)); -- 2.39.5