From: "M. Mohan Kumar" <mo...@in.ibm.com>
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=<id>,mount_tag=<tag>,socket_fd=<socket-fd>
Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com>
---
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 deletions(-)
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 1ca8369..1696675 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -312,6 +312,7 @@ 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 00f48ab..e20202a 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 921452d..1af1f54 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 0000000..3e4dc68
--- /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 <mo...@in.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+#include <sys/socket.h>
+#include <sys/un.h>
+#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 0000000..2d60b0e
--- /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 <mo...@in.ibm.com>
+ *
+ * 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 18f3020..1bdc01c 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 0096865..6323361 100644
--- a/vl.c
+++ b/vl.c
@@ -2669,7 +2669,7 @@ 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) {
@@ -2709,6 +2709,10 @@ 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));
--
1.7.6
