From 758e8e38eb582e3dc87fd55a1d234c25108a7b7f Mon Sep 17 00:00:00 2001 From: "Venkateswararao Jujjuri (JV)" Date: Mon, 14 Jun 2010 13:34:41 -0700 Subject: virtio-9p: Make infrastructure for the new security model. This patch adds required infrastructure for the new security model. - A new configure option for attr/xattr. - if CONFIG_VIRTFS will be defined if both CONFIG_LINUX and CONFIG_ATTR defined. - Defines routines related to both security models. Signed-off-by: Venkateswararao Jujjuri Signed-off-by: Anthony Liguori --- Makefile.objs | 6 ++--- Makefile.target | 2 +- configure | 37 ++++++++++++++++++++++++++++++ hw/file-op-9p.h | 20 ++++++++++++++++ hw/virtio-9p-local.c | 65 ++++++++++++++++++++++++---------------------------- hw/virtio-9p.c | 23 +++++++++++++------ hw/virtio-pci.c | 4 ++-- vl.c | 8 +++---- 8 files changed, 113 insertions(+), 52 deletions(-) diff --git a/Makefile.objs b/Makefile.objs index 2bfb6d1..53fb68e 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -35,8 +35,8 @@ net-nested-$(CONFIG_SLIRP) += slirp.o net-nested-$(CONFIG_VDE) += vde.o net-obj-y += $(addprefix net/, $(net-nested-y)) -fsdev-nested-$(CONFIG_LINUX) = qemu-fsdev.o -fsdev-obj-$(CONFIG_LINUX) += $(addprefix fsdev/, $(fsdev-nested-y)) +fsdev-nested-$(CONFIG_VIRTFS) = qemu-fsdev.o +fsdev-obj-$(CONFIG_VIRTFS) += $(addprefix fsdev/, $(fsdev-nested-y)) ###################################################################### # libqemu_common.a: Target independent part of system emulation. The @@ -233,7 +233,7 @@ sound-obj-$(CONFIG_CS4231A) += cs4231a.o adlib.o fmopl.o: QEMU_CFLAGS += -DBUILD_Y8950=0 hw-obj-$(CONFIG_SOUND) += $(sound-obj-y) -hw-obj-$(CONFIG_LINUX) += virtio-9p-debug.o virtio-9p-local.o +hw-obj-$(CONFIG_VIRTFS) += virtio-9p-debug.o virtio-9p-local.o ###################################################################### # libdis diff --git a/Makefile.target b/Makefile.target index 478b89d..f64702b 100644 --- a/Makefile.target +++ b/Makefile.target @@ -169,7 +169,7 @@ obj-y += virtio-blk.o virtio-balloon.o virtio-net.o virtio-serial-bus.o obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o obj-y += vhost_net.o obj-$(CONFIG_VHOST_NET) += vhost.o -obj-$(CONFIG_LINUX) += virtio-9p.o +obj-$(CONFIG_VIRTFS) += virtio-9p.o obj-y += rwhandler.o obj-$(CONFIG_KVM) += kvm.o kvm-all.o obj-$(CONFIG_NO_KVM) += kvm-stub.o diff --git a/configure b/configure index c0d8aa5..5699f4d 100755 --- a/configure +++ b/configure @@ -270,6 +270,7 @@ vnc_tls="" vnc_sasl="" xen="" linux_aio="" +attr="" vhost_net="" gprof="no" @@ -671,6 +672,10 @@ for opt do ;; --enable-linux-aio) linux_aio="yes" ;; + --disable-attr) attr="no" + ;; + --enable-attr) attr="yes" + ;; --enable-io-thread) io_thread="yes" ;; --disable-blobs) blobs="no" @@ -858,6 +863,8 @@ echo " --disable-vde disable support for vde network" echo " --enable-vde enable support for vde network" echo " --disable-linux-aio disable Linux AIO support" echo " --enable-linux-aio enable Linux AIO support" +echo " --disable-attr disables attr and xattr support" +echo " --enable-attr enable attr and xattr support" echo " --enable-io-thread enable IO thread" echo " --disable-blobs disable installing provided firmware blobs" echo " --kerneldir=PATH look for kernel includes in PATH" @@ -1646,6 +1653,27 @@ EOF fi ########################################## +# attr probe + +if test "$attr" != "no" ; then + cat > $TMPC < +#include +#include +int main(void) { getxattr(NULL, NULL, NULL, 0); setxattr(NULL, NULL, NULL, 0, 0); return 0; } +EOF + if compile_prog "" "-lattr" ; then + attr=yes + LIBS="-lattr $LIBS" + else + if test "$attr" = "yes" ; then + feature_not_found "ATTR" + fi + attr=no + fi +fi + +########################################## # iovec probe cat > $TMPC < @@ -2079,6 +2107,7 @@ echo "PIE user targets $user_pie" echo "vde support $vde" echo "IO thread $io_thread" echo "Linux AIO support $linux_aio" +echo "ATTR/XATTR support $attr" echo "Install blobs $blobs" echo "KVM support $kvm" echo "fdt support $fdt" @@ -2280,6 +2309,14 @@ fi if test "$linux_aio" = "yes" ; then echo "CONFIG_LINUX_AIO=y" >> $config_host_mak fi +if test "$attr" = "yes" ; then + echo "CONFIG_ATTR=y" >> $config_host_mak +fi +if test "$linux" = "yes" ; then + if test "$attr" = "yes" ; then + echo "CONFIG_VIRTFS=y" >> $config_host_mak + fi +fi if test "$blobs" = "yes" ; then echo "INSTALL_BLOBS=yes" >> $config_host_mak fi diff --git a/hw/file-op-9p.h b/hw/file-op-9p.h index f84767f..307bd1e 100644 --- a/hw/file-op-9p.h +++ b/hw/file-op-9p.h @@ -18,13 +18,33 @@ #include #include #include +#include +#define SM_LOCAL_MODE_BITS 0600 +#define SM_LOCAL_DIR_MODE_BITS 0700 + +typedef enum +{ + SM_PASSTHROUGH = 1, /* uid/gid set on fileserver files */ + SM_MAPPED, /* uid/gid part of xattr */ +} SecModel; + +typedef struct FsCred +{ + uid_t fc_uid; + gid_t fc_gid; + mode_t fc_mode; + dev_t fc_rdev; +} FsCred; typedef struct FsContext { char *fs_root; + SecModel fs_sm; uid_t uid; } FsContext; +extern void cred_init(FsCred *); + typedef struct FileOperations { int (*lstat)(FsContext *, const char *, struct stat *); diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c index 1afb731..056b4ba 100644 --- a/hw/virtio-9p-local.c +++ b/hw/virtio-9p-local.c @@ -17,6 +17,7 @@ #include #include #include +#include static const char *rpath(FsContext *ctx, const char *path) { @@ -31,45 +32,37 @@ static int local_lstat(FsContext *ctx, const char *path, struct stat *stbuf) return lstat(rpath(ctx, path), stbuf); } -static int local_setuid(FsContext *ctx, uid_t uid) +static int local_set_xattr(const char *path, FsCred *credp) { - struct passwd *pw; - gid_t groups[33]; - int ngroups; - static uid_t cur_uid = -1; - - if (cur_uid == uid) { - return 0; - } - - if (setreuid(0, 0)) { - return -1; - } - - pw = getpwuid(uid); - if (pw == NULL) { - return -1; - } - - ngroups = 33; - if (getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups) == -1) { - return -1; + int err; + if (credp->fc_uid != -1) { + err = setxattr(path, "user.virtfs.uid", &credp->fc_uid, sizeof(uid_t), + 0); + if (err) { + return err; + } } - - if (setgroups(ngroups, groups)) { - return -1; + if (credp->fc_gid != -1) { + err = setxattr(path, "user.virtfs.gid", &credp->fc_gid, sizeof(gid_t), + 0); + if (err) { + return err; + } } - - if (setregid(-1, pw->pw_gid)) { - return -1; + if (credp->fc_mode != -1) { + err = setxattr(path, "user.virtfs.mode", &credp->fc_mode, + sizeof(mode_t), 0); + if (err) { + return err; + } } - - if (setreuid(-1, uid)) { - return -1; + if (credp->fc_rdev != -1) { + err = setxattr(path, "user.virtfs.rdev", &credp->fc_rdev, + sizeof(dev_t), 0); + if (err) { + return err; + } } - - cur_uid = uid; - return 0; } @@ -183,6 +176,7 @@ static int local_open2(FsContext *ctx, const char *path, int flags, mode_t mode) return open(rpath(ctx, path), flags, mode); } + static int local_symlink(FsContext *ctx, const char *oldpath, const char *newpath) { @@ -259,12 +253,13 @@ static int local_remove(FsContext *ctx, const char *path) static int local_fsync(FsContext *ctx, int fd) { + if (0) /* Just to supress the warning. Will be removed in next patch. */ + (void)local_set_xattr(NULL, NULL); return fsync(fd); } FileOperations local_ops = { .lstat = local_lstat, - .setuid = local_setuid, .readlink = local_readlink, .close = local_close, .closedir = local_closedir, diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c index 2530488..a7ba4b6 100644 --- a/hw/virtio-9p.c +++ b/hw/virtio-9p.c @@ -67,14 +67,17 @@ static int omode_to_uflags(int8_t mode) return ret; } -static int v9fs_do_lstat(V9fsState *s, V9fsString *path, struct stat *stbuf) +void cred_init(FsCred *credp) { - return s->ops->lstat(&s->ctx, path->data, stbuf); + credp->fc_uid = -1; + credp->fc_gid = -1; + credp->fc_mode = -1; + credp->fc_rdev = -1; } -static int v9fs_do_setuid(V9fsState *s, uid_t uid) +static int v9fs_do_lstat(V9fsState *s, V9fsString *path, struct stat *stbuf) { - return s->ops->setuid(&s->ctx, uid); + return s->ops->lstat(&s->ctx, path->data, stbuf); } static ssize_t v9fs_do_readlink(V9fsState *s, V9fsString *path, V9fsString *buf) @@ -348,7 +351,6 @@ static V9fsFidState *lookup_fid(V9fsState *s, int32_t fid) for (f = s->fid_list; f; f = f->next) { if (f->fid == fid) { - v9fs_do_setuid(s, f->uid); return f; } } @@ -2253,8 +2255,15 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf) exit(1); } - if (!strcmp(fse->security_model, "passthrough") && - !strcmp(fse->security_model, "mapped")) { + if (!strcmp(fse->security_model, "passthrough")) { + /* Files on the Fileserver set to client user credentials */ + s->ctx.fs_sm = SM_PASSTHROUGH; + } else if (!strcmp(fse->security_model, "mapped")) { + /* Files on the fileserver are set to QEMU credentials. + * Client user credentials are saved in extended attributes. + */ + s->ctx.fs_sm = SM_MAPPED; + } else { /* user haven't specified a correct security option */ fprintf(stderr, "one of the following must be specified as the" "security option:\n\t security_model=passthrough \n\t " diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c index e101fa0..9accb77 100644 --- a/hw/virtio-pci.c +++ b/hw/virtio-pci.c @@ -641,7 +641,7 @@ static int virtio_balloon_init_pci(PCIDevice *pci_dev) return 0; } -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS static int virtio_9p_init_pci(PCIDevice *pci_dev) { VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev); @@ -712,7 +712,7 @@ static PCIDeviceInfo virtio_info[] = { }, .qdev.reset = virtio_pci_reset, },{ -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS .qdev.name = "virtio-9p-pci", .qdev.size = sizeof(VirtIOPCIProxy), .init = virtio_9p_init_pci, diff --git a/vl.c b/vl.c index 43d3d0e..6f559bf 100644 --- a/vl.c +++ b/vl.c @@ -147,7 +147,7 @@ int main(int argc, char **argv) #include "qemu-config.h" #include "qemu-objects.h" #include "qemu-options.h" -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS #include "fsdev/qemu-fsdev.h" #endif @@ -1532,7 +1532,7 @@ static int chardev_init_func(QemuOpts *opts, void *opaque) return 0; } -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS static int fsdev_init_func(QemuOpts *opts, void *opaque) { int ret; @@ -2281,7 +2281,7 @@ int main(int argc, char **argv, char **envp) exit(1); } break; -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS case QEMU_OPTION_fsdev: opts = qemu_opts_parse(&qemu_fsdev_opts, optarg, 1); if (!opts) { @@ -2705,7 +2705,7 @@ int main(int argc, char **argv, char **envp) if (qemu_opts_foreach(&qemu_chardev_opts, chardev_init_func, NULL, 1) != 0) exit(1); -#ifdef CONFIG_LINUX +#ifdef CONFIG_VIRTFS if (qemu_opts_foreach(&qemu_fsdev_opts, fsdev_init_func, NULL, 1) != 0) { exit(1); } -- cgit v1.1