From: Aneesh Kumar K.V Date: Mon, 18 Oct 2010 09:58:16 +0000 (+0530) Subject: virtio-9p: Use layered xattr approach X-Git-Tag: TizenStudio_2.0_p2.3.2~208^2~7070 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=fc22118d9bb56ec71655b936a29513c140e6c289;p=sdk%2Femulator%2Fqemu.git virtio-9p: Use layered xattr approach We would need this to make sure we handle the mapped security model correctly for different xattr names. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Venkateswararao Jujjuri --- diff --git a/Makefile.objs b/Makefile.objs index 816194a..be4fade 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -249,7 +249,8 @@ 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_VIRTFS) += virtio-9p-debug.o virtio-9p-local.o +hw-obj-$(CONFIG_VIRTFS) += virtio-9p-debug.o virtio-9p-local.o virtio-9p-xattr.o +hw-obj-$(CONFIG_VIRTFS) += virtio-9p-xattr-user.o ###################################################################### # libdis diff --git a/hw/file-op-9p.h b/hw/file-op-9p.h index d91b7e7..bf867b9 100644 --- a/hw/file-op-9p.h +++ b/hw/file-op-9p.h @@ -47,11 +47,14 @@ typedef struct FsCred dev_t fc_rdev; } FsCred; +struct xattr_operations; + typedef struct FsContext { char *fs_root; SecModel fs_sm; uid_t uid; + struct xattr_operations **xops; } FsContext; extern void cred_init(FsCred *); @@ -94,4 +97,12 @@ typedef struct FileOperations int (*lremovexattr)(FsContext *, const char *, const char *); void *opaque; } FileOperations; + +static inline const char *rpath(FsContext *ctx, const char *path) +{ + /* FIXME: so wrong... */ + static char buffer[4096]; + snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path); + return buffer; +} #endif diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c index 57f9243..ee63033 100644 --- a/hw/virtio-9p-local.c +++ b/hw/virtio-9p-local.c @@ -12,6 +12,7 @@ */ #include "virtio.h" #include "virtio-9p.h" +#include "virtio-9p-xattr.h" #include #include #include @@ -19,14 +20,6 @@ #include #include -static const char *rpath(FsContext *ctx, const char *path) -{ - /* FIXME: so wrong... */ - static char buffer[4096]; - snprintf(buffer, sizeof(buffer), "%s/%s", ctx->fs_root, path); - return buffer; -} - static int local_lstat(FsContext *fs_ctx, const char *path, struct stat *stbuf) { @@ -497,103 +490,25 @@ static int local_statfs(FsContext *s, const char *path, struct statfs *stbuf) static ssize_t local_lgetxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size) { - if ((ctx->fs_sm == SM_MAPPED) && - (strncmp(name, "user.virtfs.", 12) == 0)) { - /* - * Don't allow fetch of user.virtfs namesapce - * in case of mapped security - */ - errno = ENOATTR; - return -1; - } - - return lgetxattr(rpath(ctx, path), name, value, size); + return v9fs_get_xattr(ctx, path, name, value, size); } static ssize_t local_llistxattr(FsContext *ctx, const char *path, void *value, size_t size) { - ssize_t retval; - ssize_t actual_len = 0; - char *orig_value, *orig_value_start; - char *temp_value, *temp_value_start; - ssize_t xattr_len, parsed_len = 0, attr_len; - - if (ctx->fs_sm != SM_MAPPED) { - return llistxattr(rpath(ctx, path), value, size); - } - - /* Get the actual len */ - xattr_len = llistxattr(rpath(ctx, path), value, 0); - - /* Now fetch the xattr and find the actual size */ - orig_value = qemu_malloc(xattr_len); - xattr_len = llistxattr(rpath(ctx, path), orig_value, xattr_len); - - /* - * For mapped security model drop user.virtfs namespace - * from the list - */ - temp_value = qemu_mallocz(xattr_len); - temp_value_start = temp_value; - orig_value_start = orig_value; - while (xattr_len > parsed_len) { - attr_len = strlen(orig_value) + 1; - if (strncmp(orig_value, "user.virtfs.", 12) != 0) { - /* Copy this entry */ - strcat(temp_value, orig_value); - temp_value += attr_len; - actual_len += attr_len; - } - parsed_len += attr_len; - orig_value += attr_len; - } - if (!size) { - retval = actual_len; - goto out; - } else if (size >= actual_len) { - /* now copy the parsed attribute list back */ - memset(value, 0, size); - memcpy(value, temp_value_start, actual_len); - retval = actual_len; - goto out; - } - errno = ERANGE; - retval = -1; -out: - qemu_free(orig_value_start); - qemu_free(temp_value_start); - return retval; + return v9fs_list_xattr(ctx, path, value, size); } static int local_lsetxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size, int flags) { - if ((ctx->fs_sm == SM_MAPPED) && - (strncmp(name, "user.virtfs.", 12) == 0)) { - /* - * Don't allow fetch of user.virtfs namesapce - * in case of mapped security - */ - errno = EACCES; - return -1; - } - return lsetxattr(rpath(ctx, path), name, value, size, flags); + return v9fs_set_xattr(ctx, path, name, value, size, flags); } static int local_lremovexattr(FsContext *ctx, const char *path, const char *name) { - if ((ctx->fs_sm == SM_MAPPED) && - (strncmp(name, "user.virtfs.", 12) == 0)) { - /* - * Don't allow fetch of user.virtfs namesapce - * in case of mapped security - */ - errno = EACCES; - return -1; - } - return lremovexattr(rpath(ctx, path), name); + return v9fs_remove_xattr(ctx, path, name); } diff --git a/hw/virtio-9p-xattr-user.c b/hw/virtio-9p-xattr-user.c new file mode 100644 index 0000000..b14dbb9 --- /dev/null +++ b/hw/virtio-9p-xattr-user.c @@ -0,0 +1,101 @@ +/* + * Virtio 9p user. xattr callback + * + * Copyright IBM, Corp. 2010 + * + * Authors: + * Aneesh Kumar K.V + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + */ + +#include +#include "virtio.h" +#include "virtio-9p.h" +#include "file-op-9p.h" +#include "virtio-9p-xattr.h" + + +static ssize_t mp_user_getxattr(FsContext *ctx, const char *path, + const char *name, void *value, size_t size) +{ + if (strncmp(name, "user.virtfs.", 12) == 0) { + /* + * Don't allow fetch of user.virtfs namesapce + * in case of mapped security + */ + errno = ENOATTR; + return -1; + } + return lgetxattr(rpath(ctx, path), name, value, size); +} + +static ssize_t mp_user_listxattr(FsContext *ctx, const char *path, + char *name, void *value, size_t size) +{ + int name_size = strlen(name) + 1; + if (strncmp(name, "user.virtfs.", 12) == 0) { + /* + * Don't allow fetch of user.virtfs namesapce + * in case of mapped security + */ + return 0; + } + if (!value) { + return name_size; + } + + if (size < name_size) { + errno = ERANGE; + return -1; + } + + strncpy(value, name, name_size); + return name_size; +} + +static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags) +{ + if (strncmp(name, "user.virtfs.", 12) == 0) { + /* + * Don't allow fetch of user.virtfs namesapce + * in case of mapped security + */ + errno = EACCES; + return -1; + } + return lsetxattr(rpath(ctx, path), name, value, size, flags); +} + +static int mp_user_removexattr(FsContext *ctx, + const char *path, const char *name) +{ + if (strncmp(name, "user.virtfs.", 12) == 0) { + /* + * Don't allow fetch of user.virtfs namesapce + * in case of mapped security + */ + errno = EACCES; + return -1; + } + return lremovexattr(rpath(ctx, path), name); +} + +XattrOperations mapped_user_xattr = { + .name = "user.", + .getxattr = mp_user_getxattr, + .setxattr = mp_user_setxattr, + .listxattr = mp_user_listxattr, + .removexattr = mp_user_removexattr, +}; + +XattrOperations passthrough_user_xattr = { + .name = "user.", + .getxattr = pt_getxattr, + .setxattr = pt_setxattr, + .listxattr = pt_listxattr, + .removexattr = pt_removexattr, +}; diff --git a/hw/virtio-9p-xattr.c b/hw/virtio-9p-xattr.c new file mode 100644 index 0000000..5ddc3c9 --- /dev/null +++ b/hw/virtio-9p-xattr.c @@ -0,0 +1,152 @@ +/* + * Virtio 9p xattr callback + * + * Copyright IBM, Corp. 2010 + * + * Authors: + * Aneesh Kumar K.V + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + */ + +#include "virtio.h" +#include "virtio-9p.h" +#include "file-op-9p.h" +#include "virtio-9p-xattr.h" + + +static XattrOperations *get_xattr_operations(XattrOperations **h, + const char *name) +{ + XattrOperations *xops; + for (xops = *(h)++; xops != NULL; xops = *(h)++) { + if (!strncmp(name, xops->name, strlen(xops->name))) { + return xops; + } + } + return NULL; +} + +ssize_t v9fs_get_xattr(FsContext *ctx, const char *path, + const char *name, void *value, size_t size) +{ + XattrOperations *xops = get_xattr_operations(ctx->xops, name); + if (xops) { + return xops->getxattr(ctx, path, name, value, size); + } + errno = -EOPNOTSUPP; + return -1; +} + +ssize_t pt_listxattr(FsContext *ctx, const char *path, + char *name, void *value, size_t size) +{ + int name_size = strlen(name) + 1; + if (!value) { + return name_size; + } + + if (size < name_size) { + errno = ERANGE; + return -1; + } + + strncpy(value, name, name_size); + return name_size; +} + + +/* + * Get the list and pass to each layer to find out whether + * to send the data or not + */ +ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, + void *value, size_t vsize) +{ + ssize_t size = 0; + void *ovalue = value; + XattrOperations *xops; + char *orig_value, *orig_value_start; + ssize_t xattr_len, parsed_len = 0, attr_len; + + /* Get the actual len */ + xattr_len = llistxattr(rpath(ctx, path), value, 0); + + /* Now fetch the xattr and find the actual size */ + orig_value = qemu_malloc(xattr_len); + xattr_len = llistxattr(rpath(ctx, path), orig_value, xattr_len); + + /* store the orig pointer */ + orig_value_start = orig_value; + while (xattr_len > parsed_len) { + xops = get_xattr_operations(ctx->xops, orig_value); + if (!xops) { + goto next_entry; + } + + if (!value) { + size += xops->listxattr(ctx, path, orig_value, value, vsize); + } else { + size = xops->listxattr(ctx, path, orig_value, value, vsize); + if (size < 0) { + goto err_out; + } + value += size; + vsize -= size; + } +next_entry: + /* Got the next entry */ + attr_len = strlen(orig_value) + 1; + parsed_len += attr_len; + orig_value += attr_len; + } + if (value) { + size = value - ovalue; + } + +err_out: + qemu_free(orig_value_start); + return size; +} + +int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags) +{ + XattrOperations *xops = get_xattr_operations(ctx->xops, name); + if (xops) { + return xops->setxattr(ctx, path, name, value, size, flags); + } + errno = -EOPNOTSUPP; + return -1; + +} + +int v9fs_remove_xattr(FsContext *ctx, + const char *path, const char *name) +{ + XattrOperations *xops = get_xattr_operations(ctx->xops, name); + if (xops) { + return xops->removexattr(ctx, path, name); + } + errno = -EOPNOTSUPP; + return -1; + +} + +XattrOperations *mapped_xattr_ops[] = { + &mapped_user_xattr, + NULL, +}; + +XattrOperations *passthrough_xattr_ops[] = { + &passthrough_user_xattr, + NULL, +}; + +/* for .user none model should be same as passthrough */ +XattrOperations *none_xattr_ops[] = { + &passthrough_user_xattr, + NULL, +}; diff --git a/hw/virtio-9p-xattr.h b/hw/virtio-9p-xattr.h new file mode 100644 index 0000000..15632f8 --- /dev/null +++ b/hw/virtio-9p-xattr.h @@ -0,0 +1,69 @@ +/* + * Virtio 9p + * + * Copyright IBM, Corp. 2010 + * + * Authors: + * Aneesh Kumar K.V + * + * 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_XATTR_H +#define _QEMU_VIRTIO_9P_XATTR_H + +#include + +typedef struct xattr_operations +{ + const char *name; + ssize_t (*getxattr)(FsContext *ctx, const char *path, + const char *name, void *value, size_t size); + ssize_t (*listxattr)(FsContext *ctx, const char *path, + char *name, void *value, size_t size); + int (*setxattr)(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags); + int (*removexattr)(FsContext *ctx, + const char *path, const char *name); +} XattrOperations; + + +extern XattrOperations mapped_user_xattr; +extern XattrOperations passthrough_user_xattr; + +extern XattrOperations *mapped_xattr_ops[]; +extern XattrOperations *passthrough_xattr_ops[]; +extern XattrOperations *none_xattr_ops[]; + +extern ssize_t v9fs_get_xattr(FsContext *ctx, const char *path, + const char *name, void *value, size_t size); +extern ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, + void *value, size_t vsize); +extern int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags); +extern int v9fs_remove_xattr(FsContext *ctx, + const char *path, const char *name); +extern ssize_t pt_listxattr(FsContext *ctx, const char *path, + char *name, void *value, size_t size); + +static inline ssize_t pt_getxattr(FsContext *ctx, const char *path, + const char *name, void *value, size_t size) +{ + return lgetxattr(rpath(ctx, path), name, value, size); +} + +static inline int pt_setxattr(FsContext *ctx, const char *path, + const char *name, void *value, + size_t size, int flags) +{ + return lsetxattr(rpath(ctx, path), name, value, size, flags); +} + +static inline int pt_removexattr(FsContext *ctx, + const char *path, const char *name) +{ + return lremovexattr(rpath(ctx, path), name); +} + +#endif diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c index cb6366b..4586cce 100644 --- a/hw/virtio-9p.c +++ b/hw/virtio-9p.c @@ -17,6 +17,7 @@ #include "virtio-9p.h" #include "fsdev/qemu-fsdev.h" #include "virtio-9p-debug.h" +#include "virtio-9p-xattr.h" int debug_9p_pdu; @@ -3712,23 +3713,26 @@ VirtIODevice *virtio_9p_init(DeviceState *dev, V9fsConf *conf) if (!strcmp(fse->security_model, "passthrough")) { /* Files on the Fileserver set to client user credentials */ s->ctx.fs_sm = SM_PASSTHROUGH; + s->ctx.xops = passthrough_xattr_ops; } 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; + s->ctx.xops = mapped_xattr_ops; } else if (!strcmp(fse->security_model, "none")) { /* * Files on the fileserver are set to QEMU credentials. */ s->ctx.fs_sm = SM_NONE; - + s->ctx.xops = none_xattr_ops; } else { fprintf(stderr, "Default to security_model=none. You may want" " enable advanced security model using " "security option:\n\t security_model=passthrough \n\t " "security_model=mapped\n"); s->ctx.fs_sm = SM_NONE; + s->ctx.xops = none_xattr_ops; } if (lstat(fse->path, &stat)) {