diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2017-03-01 13:53:20 +0000 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2017-03-01 13:53:20 +0000 |
commit | 7287e3556fdc56bfd0666a67d6b1d3ca9ce04083 (patch) | |
tree | 4e80025a84bfdf6ac424d746920a3f383c8eb0d8 /hw/9pfs | |
parent | e3280ffbf59b1546e25b40a87bd3556b211d9191 (diff) | |
parent | c23d5f1d5bc0e23aeb845b1af8f996f16783ce98 (diff) | |
download | qemu-7287e3556fdc56bfd0666a67d6b1d3ca9ce04083.zip qemu-7287e3556fdc56bfd0666a67d6b1d3ca9ce04083.tar.gz qemu-7287e3556fdc56bfd0666a67d6b1d3ca9ce04083.tar.bz2 |
Merge remote-tracking branch 'remotes/gkurz/tags/cve-2016-9602-for-upstream' into staging
This pull request have all the fixes for CVE-2016-9602, so that it can
be easily picked up by downstreams, as suggested by Michel Tokarev.
# gpg: Signature made Tue 28 Feb 2017 10:21:32 GMT
# gpg: using DSA key 0x02FC3AEB0101DBC2
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg: aka "Greg Kurz <groug@free.fr>"
# gpg: aka "Greg Kurz <gkurz@linux.vnet.ibm.com>"
# gpg: aka "Gregory Kurz (Groug) <groug@free.fr>"
# gpg: aka "[jpeg image of size 3330]"
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg: There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 2BD4 3B44 535E C0A7 9894 DBA2 02FC 3AEB 0101 DBC2
* remotes/gkurz/tags/cve-2016-9602-for-upstream: (28 commits)
9pfs: local: drop unused code
9pfs: local: open2: don't follow symlinks
9pfs: local: mkdir: don't follow symlinks
9pfs: local: mknod: don't follow symlinks
9pfs: local: symlink: don't follow symlinks
9pfs: local: chown: don't follow symlinks
9pfs: local: chmod: don't follow symlinks
9pfs: local: link: don't follow symlinks
9pfs: local: improve error handling in link op
9pfs: local: rename: use renameat
9pfs: local: renameat: don't follow symlinks
9pfs: local: lstat: don't follow symlinks
9pfs: local: readlink: don't follow symlinks
9pfs: local: truncate: don't follow symlinks
9pfs: local: statfs: don't follow symlinks
9pfs: local: utimensat: don't follow symlinks
9pfs: local: remove: don't follow symlinks
9pfs: local: unlinkat: don't follow symlinks
9pfs: local: lremovexattr: don't follow symlinks
9pfs: local: lsetxattr: don't follow symlinks
...
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/9pfs')
-rw-r--r-- | hw/9pfs/9p-local.c | 1023 | ||||
-rw-r--r-- | hw/9pfs/9p-local.h | 20 | ||||
-rw-r--r-- | hw/9pfs/9p-posix-acl.c | 44 | ||||
-rw-r--r-- | hw/9pfs/9p-util.c | 69 | ||||
-rw-r--r-- | hw/9pfs/9p-util.h | 54 | ||||
-rw-r--r-- | hw/9pfs/9p-xattr-user.c | 24 | ||||
-rw-r--r-- | hw/9pfs/9p-xattr.c | 166 | ||||
-rw-r--r-- | hw/9pfs/9p-xattr.h | 87 | ||||
-rw-r--r-- | hw/9pfs/Makefile.objs | 2 |
9 files changed, 893 insertions, 596 deletions
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index 2369b91..f22a3c3 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -13,7 +13,9 @@ #include "qemu/osdep.h" #include "9p.h" +#include "9p-local.h" #include "9p-xattr.h" +#include "9p-util.h" #include "fsdev/qemu-fsdev.h" /* local_ops */ #include <arpa/inet.h> #include <pwd.h> @@ -43,40 +45,62 @@ #define BTRFS_SUPER_MAGIC 0x9123683E #endif -#define VIRTFS_META_DIR ".virtfs_metadata" +typedef struct { + int mountfd; +} LocalData; -static char *local_mapped_attr_path(FsContext *ctx, const char *path) +int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags, + mode_t mode) { - int dirlen; - const char *name = strrchr(path, '/'); - if (name) { - dirlen = name - path; - ++name; - } else { - name = path; - dirlen = 0; + LocalData *data = fs_ctx->private; + + /* All paths are relative to the path data->mountfd points to */ + while (*path == '/') { + path++; } - return g_strdup_printf("%s/%.*s/%s/%s", ctx->fs_root, - dirlen, path, VIRTFS_META_DIR, name); + + return relative_openat_nofollow(data->mountfd, path, flags, mode); +} + +int local_opendir_nofollow(FsContext *fs_ctx, const char *path) +{ + return local_open_nofollow(fs_ctx, path, O_DIRECTORY | O_RDONLY, 0); +} + +static void renameat_preserve_errno(int odirfd, const char *opath, int ndirfd, + const char *npath) +{ + int serrno = errno; + renameat(odirfd, opath, ndirfd, npath); + errno = serrno; } -static FILE *local_fopen(const char *path, const char *mode) +static void unlinkat_preserve_errno(int dirfd, const char *path, int flags) +{ + int serrno = errno; + unlinkat(dirfd, path, flags); + errno = serrno; +} + +#define VIRTFS_META_DIR ".virtfs_metadata" + +static FILE *local_fopenat(int dirfd, const char *name, const char *mode) { int fd, o_mode = 0; FILE *fp; - int flags = O_NOFOLLOW; + int flags; /* * only supports two modes */ if (mode[0] == 'r') { - flags |= O_RDONLY; + flags = O_RDONLY; } else if (mode[0] == 'w') { - flags |= O_WRONLY | O_TRUNC | O_CREAT; + flags = O_WRONLY | O_TRUNC | O_CREAT; o_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH; } else { return NULL; } - fd = open(path, flags, o_mode); + fd = openat_file(dirfd, name, flags, o_mode); if (fd == -1) { return NULL; } @@ -88,16 +112,20 @@ static FILE *local_fopen(const char *path, const char *mode) } #define ATTR_MAX 100 -static void local_mapped_file_attr(FsContext *ctx, const char *path, +static void local_mapped_file_attr(int dirfd, const char *name, struct stat *stbuf) { FILE *fp; char buf[ATTR_MAX]; - char *attr_path; + int map_dirfd; - attr_path = local_mapped_attr_path(ctx, path); - fp = local_fopen(attr_path, "r"); - g_free(attr_path); + map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); + if (map_dirfd == -1) { + return; + } + + fp = local_fopenat(map_dirfd, name, "r"); + close_preserve_errno(map_dirfd); if (!fp) { return; } @@ -119,12 +147,17 @@ static void local_mapped_file_attr(FsContext *ctx, const char *path, static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) { - int err; - char *buffer; - char *path = fs_path->data; + int err = -1; + char *dirpath = g_path_get_dirname(fs_path->data); + char *name = g_path_get_basename(fs_path->data); + int dirfd; + + dirfd = local_opendir_nofollow(fs_ctx, dirpath); + if (dirfd == -1) { + goto out; + } - buffer = rpath(fs_ctx, path); - err = lstat(buffer, stbuf); + err = fstatat(dirfd, name, stbuf, AT_SYMLINK_NOFOLLOW); if (err) { goto err_out; } @@ -134,87 +167,83 @@ static int local_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf) gid_t tmp_gid; mode_t tmp_mode; dev_t tmp_dev; - if (getxattr(buffer, "user.virtfs.uid", &tmp_uid, sizeof(uid_t)) > 0) { + + if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.uid", &tmp_uid, + sizeof(uid_t)) > 0) { stbuf->st_uid = le32_to_cpu(tmp_uid); } - if (getxattr(buffer, "user.virtfs.gid", &tmp_gid, sizeof(gid_t)) > 0) { + if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.gid", &tmp_gid, + sizeof(gid_t)) > 0) { stbuf->st_gid = le32_to_cpu(tmp_gid); } - if (getxattr(buffer, "user.virtfs.mode", - &tmp_mode, sizeof(mode_t)) > 0) { + if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.mode", &tmp_mode, + sizeof(mode_t)) > 0) { stbuf->st_mode = le32_to_cpu(tmp_mode); } - if (getxattr(buffer, "user.virtfs.rdev", &tmp_dev, sizeof(dev_t)) > 0) { + if (fgetxattrat_nofollow(dirfd, name, "user.virtfs.rdev", &tmp_dev, + sizeof(dev_t)) > 0) { stbuf->st_rdev = le64_to_cpu(tmp_dev); } } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - local_mapped_file_attr(fs_ctx, path, stbuf); + local_mapped_file_attr(dirfd, name, stbuf); } err_out: - g_free(buffer); - return err; -} - -static int local_create_mapped_attr_dir(FsContext *ctx, const char *path) -{ - int err; - char *attr_dir; - char *tmp_path = g_strdup(path); - - attr_dir = g_strdup_printf("%s/%s/%s", - ctx->fs_root, dirname(tmp_path), VIRTFS_META_DIR); - - err = mkdir(attr_dir, 0700); - if (err < 0 && errno == EEXIST) { - err = 0; - } - g_free(attr_dir); - g_free(tmp_path); + close_preserve_errno(dirfd); +out: + g_free(name); + g_free(dirpath); return err; } -static int local_set_mapped_file_attr(FsContext *ctx, - const char *path, FsCred *credp) +static int local_set_mapped_file_attrat(int dirfd, const char *name, + FsCred *credp) { FILE *fp; - int ret = 0; + int ret; char buf[ATTR_MAX]; - char *attr_path; int uid = -1, gid = -1, mode = -1, rdev = -1; + int map_dirfd; + + ret = mkdirat(dirfd, VIRTFS_META_DIR, 0700); + if (ret < 0 && errno != EEXIST) { + return -1; + } - attr_path = local_mapped_attr_path(ctx, path); - fp = local_fopen(attr_path, "r"); + map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); + if (map_dirfd == -1) { + return -1; + } + + fp = local_fopenat(map_dirfd, name, "r"); if (!fp) { - goto create_map_file; + if (errno == ENOENT) { + goto update_map_file; + } else { + close_preserve_errno(map_dirfd); + return -1; + } } memset(buf, 0, ATTR_MAX); while (fgets(buf, ATTR_MAX, fp)) { if (!strncmp(buf, "virtfs.uid", 10)) { - uid = atoi(buf+11); + uid = atoi(buf + 11); } else if (!strncmp(buf, "virtfs.gid", 10)) { - gid = atoi(buf+11); + gid = atoi(buf + 11); } else if (!strncmp(buf, "virtfs.mode", 11)) { - mode = atoi(buf+12); + mode = atoi(buf + 12); } else if (!strncmp(buf, "virtfs.rdev", 11)) { - rdev = atoi(buf+12); + rdev = atoi(buf + 12); } memset(buf, 0, ATTR_MAX); } fclose(fp); - goto update_map_file; - -create_map_file: - ret = local_create_mapped_attr_dir(ctx, path); - if (ret < 0) { - goto err_out; - } update_map_file: - fp = local_fopen(attr_path, "w"); + fp = local_fopenat(map_dirfd, name, "w"); + close_preserve_errno(map_dirfd); if (!fp) { - ret = -1; - goto err_out; + return -1; } if (credp->fc_uid != -1) { @@ -230,7 +259,6 @@ update_map_file: rdev = credp->fc_rdev; } - if (uid != -1) { fprintf(fp, "virtfs.uid=%d\n", uid); } @@ -245,39 +273,71 @@ update_map_file: } fclose(fp); -err_out: - g_free(attr_path); + return 0; +} + +static int fchmodat_nofollow(int dirfd, const char *name, mode_t mode) +{ + int fd, ret; + + /* FIXME: this should be handled with fchmodat(AT_SYMLINK_NOFOLLOW). + * Unfortunately, the linux kernel doesn't implement it yet. As an + * alternative, let's open the file and use fchmod() instead. This + * may fail depending on the permissions of the file, but it is the + * best we can do to avoid TOCTTOU. We first try to open read-only + * in case name points to a directory. If that fails, we try write-only + * in case name doesn't point to a directory. + */ + fd = openat_file(dirfd, name, O_RDONLY, 0); + if (fd == -1) { + /* In case the file is writable-only and isn't a directory. */ + if (errno == EACCES) { + fd = openat_file(dirfd, name, O_WRONLY, 0); + } + if (fd == -1 && errno == EISDIR) { + errno = EACCES; + } + } + if (fd == -1) { + return -1; + } + ret = fchmod(fd, mode); + close_preserve_errno(fd); return ret; } -static int local_set_xattr(const char *path, FsCred *credp) +static int local_set_xattrat(int dirfd, const char *path, FsCred *credp) { int err; if (credp->fc_uid != -1) { uint32_t tmp_uid = cpu_to_le32(credp->fc_uid); - err = setxattr(path, "user.virtfs.uid", &tmp_uid, sizeof(uid_t), 0); + err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.uid", &tmp_uid, + sizeof(uid_t), 0); if (err) { return err; } } if (credp->fc_gid != -1) { uint32_t tmp_gid = cpu_to_le32(credp->fc_gid); - err = setxattr(path, "user.virtfs.gid", &tmp_gid, sizeof(gid_t), 0); + err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.gid", &tmp_gid, + sizeof(gid_t), 0); if (err) { return err; } } if (credp->fc_mode != -1) { uint32_t tmp_mode = cpu_to_le32(credp->fc_mode); - err = setxattr(path, "user.virtfs.mode", &tmp_mode, sizeof(mode_t), 0); + err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.mode", &tmp_mode, + sizeof(mode_t), 0); if (err) { return err; } } if (credp->fc_rdev != -1) { uint64_t tmp_rdev = cpu_to_le64(credp->fc_rdev); - err = setxattr(path, "user.virtfs.rdev", &tmp_rdev, sizeof(dev_t), 0); + err = fsetxattrat_nofollow(dirfd, path, "user.virtfs.rdev", &tmp_rdev, + sizeof(dev_t), 0); if (err) { return err; } @@ -285,58 +345,56 @@ static int local_set_xattr(const char *path, FsCred *credp) return 0; } -static int local_post_create_passthrough(FsContext *fs_ctx, const char *path, - FsCred *credp) +static int local_set_cred_passthrough(FsContext *fs_ctx, int dirfd, + const char *name, FsCred *credp) { - char *buffer; - - buffer = rpath(fs_ctx, path); - if (lchown(buffer, credp->fc_uid, credp->fc_gid) < 0) { + if (fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, + AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) < 0) { /* * If we fail to change ownership and if we are * using security model none. Ignore the error */ if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { - goto err; + return -1; } } - if (chmod(buffer, credp->fc_mode & 07777) < 0) { - goto err; - } - - g_free(buffer); - return 0; -err: - g_free(buffer); - return -1; + return fchmodat_nofollow(dirfd, name, credp->fc_mode & 07777); } static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath *fs_path, char *buf, size_t bufsz) { ssize_t tsize = -1; - char *buffer; - char *path = fs_path->data; if ((fs_ctx->export_flags & V9FS_SM_MAPPED) || (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) { int fd; - buffer = rpath(fs_ctx, path); - fd = open(buffer, O_RDONLY | O_NOFOLLOW); - g_free(buffer); + + fd = local_open_nofollow(fs_ctx, fs_path->data, O_RDONLY, 0); if (fd == -1) { return -1; } do { tsize = read(fd, (void *)buf, bufsz); } while (tsize == -1 && errno == EINTR); - close(fd); + close_preserve_errno(fd); } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - tsize = readlink(buffer, buf, bufsz); - g_free(buffer); + char *dirpath = g_path_get_dirname(fs_path->data); + char *name = g_path_get_basename(fs_path->data); + int dirfd; + + dirfd = local_opendir_nofollow(fs_ctx, dirpath); + if (dirfd == -1) { + goto out; + } + + tsize = readlinkat(dirfd, name, buf, bufsz); + close_preserve_errno(dirfd); + out: + g_free(name); + g_free(dirpath); } return tsize; } @@ -354,27 +412,32 @@ static int local_closedir(FsContext *ctx, V9fsFidOpenState *fs) static int local_open(FsContext *ctx, V9fsPath *fs_path, int flags, V9fsFidOpenState *fs) { - char *buffer; - char *path = fs_path->data; + int fd; - buffer = rpath(ctx, path); - fs->fd = open(buffer, flags | O_NOFOLLOW); - g_free(buffer); + fd = local_open_nofollow(ctx, fs_path->data, flags, 0); + if (fd == -1) { + return -1; + } + fs->fd = fd; return fs->fd; } static int local_opendir(FsContext *ctx, V9fsPath *fs_path, V9fsFidOpenState *fs) { - char *buffer; - char *path = fs_path->data; + int dirfd; + DIR *stream; + + dirfd = local_opendir_nofollow(ctx, fs_path->data); + if (dirfd == -1) { + return -1; + } - buffer = rpath(ctx, path); - fs->dir.stream = opendir(buffer); - g_free(buffer); - if (!fs->dir.stream) { + stream = fdopendir(dirfd); + if (!stream) { return -1; } + fs->dir.stream = stream; return 0; } @@ -463,145 +526,122 @@ static ssize_t local_pwritev(FsContext *ctx, V9fsFidOpenState *fs, static int local_chmod(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) { - char *buffer; + char *dirpath = g_path_get_dirname(fs_path->data); + char *name = g_path_get_basename(fs_path->data); int ret = -1; - char *path = fs_path->data; + int dirfd; + + dirfd = local_opendir_nofollow(fs_ctx, dirpath); + if (dirfd == -1) { + goto out; + } if (fs_ctx->export_flags & V9FS_SM_MAPPED) { - buffer = rpath(fs_ctx, path); - ret = local_set_xattr(buffer, credp); - g_free(buffer); + ret = local_set_xattrat(dirfd, name, credp); } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - return local_set_mapped_file_attr(fs_ctx, path, credp); - } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || - (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - ret = chmod(buffer, credp->fc_mode); - g_free(buffer); + ret = local_set_mapped_file_attrat(dirfd, name, credp); + } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || + fs_ctx->export_flags & V9FS_SM_NONE) { + ret = fchmodat_nofollow(dirfd, name, credp->fc_mode); } + close_preserve_errno(dirfd); + +out: + g_free(dirpath); + g_free(name); return ret; } static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, FsCred *credp) { - char *path; int err = -1; - int serrno = 0; - V9fsString fullname; - char *buffer = NULL; + int dirfd; - v9fs_string_init(&fullname); - v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); - path = fullname.data; + dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); + if (dirfd == -1) { + return -1; + } - /* Determine the security model */ - if (fs_ctx->export_flags & V9FS_SM_MAPPED) { - buffer = rpath(fs_ctx, path); - err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); + if (fs_ctx->export_flags & V9FS_SM_MAPPED || + fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { + err = mknodat(dirfd, name, SM_LOCAL_MODE_BITS | S_IFREG, 0); if (err == -1) { goto out; } - err = local_set_xattr(buffer, credp); - if (err == -1) { - serrno = errno; - goto err_end; - } - } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - buffer = rpath(fs_ctx, path); - err = mknod(buffer, SM_LOCAL_MODE_BITS|S_IFREG, 0); - if (err == -1) { - goto out; + if (fs_ctx->export_flags & V9FS_SM_MAPPED) { + err = local_set_xattrat(dirfd, name, credp); + } else { + err = local_set_mapped_file_attrat(dirfd, name, credp); } - err = local_set_mapped_file_attr(fs_ctx, path, credp); if (err == -1) { - serrno = errno; goto err_end; } - } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || - (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - err = mknod(buffer, credp->fc_mode, credp->fc_rdev); + } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || + fs_ctx->export_flags & V9FS_SM_NONE) { + err = mknodat(dirfd, name, credp->fc_mode, credp->fc_rdev); if (err == -1) { goto out; } - err = local_post_create_passthrough(fs_ctx, path, credp); + err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); if (err == -1) { - serrno = errno; goto err_end; } } goto out; err_end: - remove(buffer); - errno = serrno; + unlinkat_preserve_errno(dirfd, name, 0); out: - g_free(buffer); - v9fs_string_free(&fullname); + close_preserve_errno(dirfd); return err; } static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, FsCred *credp) { - char *path; int err = -1; - int serrno = 0; - V9fsString fullname; - char *buffer = NULL; + int dirfd; - v9fs_string_init(&fullname); - v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); - path = fullname.data; + dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); + if (dirfd == -1) { + return -1; + } - /* Determine the security model */ - if (fs_ctx->export_flags & V9FS_SM_MAPPED) { - buffer = rpath(fs_ctx, path); - err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); + if (fs_ctx->export_flags & V9FS_SM_MAPPED || + fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { + err = mkdirat(dirfd, name, SM_LOCAL_DIR_MODE_BITS); if (err == -1) { goto out; } - credp->fc_mode = credp->fc_mode|S_IFDIR; - err = local_set_xattr(buffer, credp); - if (err == -1) { - serrno = errno; - goto err_end; - } - } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - buffer = rpath(fs_ctx, path); - err = mkdir(buffer, SM_LOCAL_DIR_MODE_BITS); - if (err == -1) { - goto out; + credp->fc_mode = credp->fc_mode | S_IFDIR; + + if (fs_ctx->export_flags & V9FS_SM_MAPPED) { + err = local_set_xattrat(dirfd, name, credp); + } else { + err = local_set_mapped_file_attrat(dirfd, name, credp); } - credp->fc_mode = credp->fc_mode|S_IFDIR; - err = local_set_mapped_file_attr(fs_ctx, path, credp); if (err == -1) { - serrno = errno; goto err_end; } - } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || - (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - err = mkdir(buffer, credp->fc_mode); + } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || + fs_ctx->export_flags & V9FS_SM_NONE) { + err = mkdirat(dirfd, name, credp->fc_mode); if (err == -1) { goto out; } - err = local_post_create_passthrough(fs_ctx, path, credp); + err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); if (err == -1) { - serrno = errno; goto err_end; } } goto out; err_end: - remove(buffer); - errno = serrno; + unlinkat_preserve_errno(dirfd, name, AT_REMOVEDIR); out: - g_free(buffer); - v9fs_string_free(&fullname); + close_preserve_errno(dirfd); return err; } @@ -649,62 +689,45 @@ static int local_fstat(FsContext *fs_ctx, int fid_type, static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, int flags, FsCred *credp, V9fsFidOpenState *fs) { - char *path; int fd = -1; int err = -1; - int serrno = 0; - V9fsString fullname; - char *buffer = NULL; + int dirfd; /* * Mark all the open to not follow symlinks */ flags |= O_NOFOLLOW; - v9fs_string_init(&fullname); - v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); - path = fullname.data; + dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); + if (dirfd == -1) { + return -1; + } /* Determine the security model */ - if (fs_ctx->export_flags & V9FS_SM_MAPPED) { - buffer = rpath(fs_ctx, path); - fd = open(buffer, flags, SM_LOCAL_MODE_BITS); + if (fs_ctx->export_flags & V9FS_SM_MAPPED || + fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { + fd = openat_file(dirfd, name, flags, SM_LOCAL_MODE_BITS); if (fd == -1) { - err = fd; goto out; } credp->fc_mode = credp->fc_mode|S_IFREG; - /* Set cleint credentials in xattr */ - err = local_set_xattr(buffer, credp); - if (err == -1) { - serrno = errno; - goto err_end; - } - } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - buffer = rpath(fs_ctx, path); - fd = open(buffer, flags, SM_LOCAL_MODE_BITS); - if (fd == -1) { - err = fd; - goto out; + if (fs_ctx->export_flags & V9FS_SM_MAPPED) { + /* Set cleint credentials in xattr */ + err = local_set_xattrat(dirfd, name, credp); + } else { + err = local_set_mapped_file_attrat(dirfd, name, credp); } - credp->fc_mode = credp->fc_mode|S_IFREG; - /* Set client credentials in .virtfs_metadata directory files */ - err = local_set_mapped_file_attr(fs_ctx, path, credp); if (err == -1) { - serrno = errno; goto err_end; } } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - fd = open(buffer, flags, credp->fc_mode); + fd = openat_file(dirfd, name, flags, credp->fc_mode); if (fd == -1) { - err = fd; goto out; } - err = local_post_create_passthrough(fs_ctx, path, credp); + err = local_set_cred_passthrough(fs_ctx, dirfd, name, credp); if (err == -1) { - serrno = errno; goto err_end; } } @@ -713,12 +736,11 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name, goto out; err_end: - close(fd); - remove(buffer); - errno = serrno; + unlinkat_preserve_errno(dirfd, name, + flags & O_DIRECTORY ? AT_REMOVEDIR : 0); + close_preserve_errno(fd); out: - g_free(buffer); - v9fs_string_free(&fullname); + close_preserve_errno(dirfd); return err; } @@ -727,23 +749,22 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath, V9fsPath *dir_path, const char *name, FsCred *credp) { int err = -1; - int serrno = 0; - char *newpath; - V9fsString fullname; - char *buffer = NULL; + int dirfd; - v9fs_string_init(&fullname); - v9fs_string_sprintf(&fullname, "%s/%s", dir_path->data, name); - newpath = fullname.data; + dirfd = local_opendir_nofollow(fs_ctx, dir_path->data); + if (dirfd == -1) { + return -1; + } /* Determine the security model */ - if (fs_ctx->export_flags & V9FS_SM_MAPPED) { + if (fs_ctx->export_flags & V9FS_SM_MAPPED || + fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { int fd; ssize_t oldpath_size, write_size; - buffer = rpath(fs_ctx, newpath); - fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); + + fd = openat_file(dirfd, name, O_CREAT | O_EXCL | O_RDWR, + SM_LOCAL_MODE_BITS); if (fd == -1) { - err = fd; goto out; } /* Write the oldpath (target) to the file. */ @@ -751,218 +772,204 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath, do { write_size = write(fd, (void *)oldpath, oldpath_size); } while (write_size == -1 && errno == EINTR); + close_preserve_errno(fd); if (write_size != oldpath_size) { - serrno = errno; - close(fd); - err = -1; goto err_end; } - close(fd); /* Set cleint credentials in symlink's xattr */ - credp->fc_mode = credp->fc_mode|S_IFLNK; - err = local_set_xattr(buffer, credp); - if (err == -1) { - serrno = errno; - goto err_end; - } - } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - int fd; - ssize_t oldpath_size, write_size; - buffer = rpath(fs_ctx, newpath); - fd = open(buffer, O_CREAT|O_EXCL|O_RDWR|O_NOFOLLOW, SM_LOCAL_MODE_BITS); - if (fd == -1) { - err = fd; - goto out; - } - /* Write the oldpath (target) to the file. */ - oldpath_size = strlen(oldpath); - do { - write_size = write(fd, (void *)oldpath, oldpath_size); - } while (write_size == -1 && errno == EINTR); + credp->fc_mode = credp->fc_mode | S_IFLNK; - if (write_size != oldpath_size) { - serrno = errno; - close(fd); - err = -1; - goto err_end; + if (fs_ctx->export_flags & V9FS_SM_MAPPED) { + err = local_set_xattrat(dirfd, name, credp); + } else { + err = local_set_mapped_file_attrat(dirfd, name, credp); } - close(fd); - /* Set cleint credentials in symlink's xattr */ - credp->fc_mode = credp->fc_mode|S_IFLNK; - err = local_set_mapped_file_attr(fs_ctx, newpath, credp); if (err == -1) { - serrno = errno; goto err_end; } - } else if ((fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || - (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, newpath); - err = symlink(oldpath, buffer); + } else if (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH || + fs_ctx->export_flags & V9FS_SM_NONE) { + err = symlinkat(oldpath, dirfd, name); if (err) { goto out; } - err = lchown(buffer, credp->fc_uid, credp->fc_gid); + err = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, + AT_SYMLINK_NOFOLLOW); if (err == -1) { /* * If we fail to change ownership and if we are * using security model none. Ignore the error */ if ((fs_ctx->export_flags & V9FS_SEC_MASK) != V9FS_SM_NONE) { - serrno = errno; goto err_end; - } else + } else { err = 0; + } } } goto out; err_end: - remove(buffer); - errno = serrno; + unlinkat_preserve_errno(dirfd, name, 0); out: - g_free(buffer); - v9fs_string_free(&fullname); + close_preserve_errno(dirfd); return err; } static int local_link(FsContext *ctx, V9fsPath *oldpath, V9fsPath *dirpath, const char *name) { - int ret; - V9fsString newpath; - char *buffer, *buffer1; + char *odirpath = g_path_get_dirname(oldpath->data); + char *oname = g_path_get_basename(oldpath->data); + int ret = -1; + int odirfd, ndirfd; + + odirfd = local_opendir_nofollow(ctx, odirpath); + if (odirfd == -1) { + goto out; + } - v9fs_string_init(&newpath); - v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name); + ndirfd = local_opendir_nofollow(ctx, dirpath->data); + if (ndirfd == -1) { + close_preserve_errno(odirfd); + goto out; + } - buffer = rpath(ctx, oldpath->data); - buffer1 = rpath(ctx, newpath.data); - ret = link(buffer, buffer1); - g_free(buffer); - g_free(buffer1); + ret = linkat(odirfd, oname, ndirfd, name, 0); + if (ret < 0) { + goto out_close; + } /* now link the virtfs_metadata files */ - if (!ret && (ctx->export_flags & V9FS_SM_MAPPED_FILE)) { - /* Link the .virtfs_metadata files. Create the metada directory */ - ret = local_create_mapped_attr_dir(ctx, newpath.data); - if (ret < 0) { - goto err_out; + if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { + int omap_dirfd, nmap_dirfd; + + ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700); + if (ret < 0 && errno != EEXIST) { + goto err_undo_link; } - buffer = local_mapped_attr_path(ctx, oldpath->data); - buffer1 = local_mapped_attr_path(ctx, newpath.data); - ret = link(buffer, buffer1); - g_free(buffer); - g_free(buffer1); + + omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR); + if (omap_dirfd == -1) { + goto err; + } + + nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR); + if (nmap_dirfd == -1) { + close_preserve_errno(omap_dirfd); + goto err; + } + + ret = linkat(omap_dirfd, oname, nmap_dirfd, name, 0); + close_preserve_errno(nmap_dirfd); + close_preserve_errno(omap_dirfd); if (ret < 0 && errno != ENOENT) { - goto err_out; + goto err_undo_link; } - } -err_out: - v9fs_string_free(&newpath); - return ret; -} -static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) -{ - char *buffer; - int ret; - char *path = fs_path->data; + ret = 0; + } + goto out_close; - buffer = rpath(ctx, path); - ret = truncate(buffer, size); - g_free(buffer); +err: + ret = -1; +err_undo_link: + unlinkat_preserve_errno(ndirfd, name, 0); +out_close: + close_preserve_errno(ndirfd); + close_preserve_errno(odirfd); +out: + g_free(oname); + g_free(odirpath); return ret; } -static int local_rename(FsContext *ctx, const char *oldpath, - const char *newpath) +static int local_truncate(FsContext *ctx, V9fsPath *fs_path, off_t size) { - int err; - char *buffer, *buffer1; + int fd, ret; - if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { - err = local_create_mapped_attr_dir(ctx, newpath); - if (err < 0) { - return err; - } - /* rename the .virtfs_metadata files */ - buffer = local_mapped_attr_path(ctx, oldpath); - buffer1 = local_mapped_attr_path(ctx, newpath); - err = rename(buffer, buffer1); - g_free(buffer); - g_free(buffer1); - if (err < 0 && errno != ENOENT) { - return err; - } + fd = local_open_nofollow(ctx, fs_path->data, O_WRONLY, 0); + if (fd == -1) { + return -1; } - - buffer = rpath(ctx, oldpath); - buffer1 = rpath(ctx, newpath); - err = rename(buffer, buffer1); - g_free(buffer); - g_free(buffer1); - return err; + ret = ftruncate(fd, size); + close_preserve_errno(fd); + return ret; } static int local_chown(FsContext *fs_ctx, V9fsPath *fs_path, FsCred *credp) { - char *buffer; + char *dirpath = g_path_get_dirname(fs_path->data); + char *name = g_path_get_basename(fs_path->data); int ret = -1; - char *path = fs_path->data; + int dirfd; + + dirfd = local_opendir_nofollow(fs_ctx, dirpath); + if (dirfd == -1) { + goto out; + } if ((credp->fc_uid == -1 && credp->fc_gid == -1) || (fs_ctx->export_flags & V9FS_SM_PASSTHROUGH) || (fs_ctx->export_flags & V9FS_SM_NONE)) { - buffer = rpath(fs_ctx, path); - ret = lchown(buffer, credp->fc_uid, credp->fc_gid); - g_free(buffer); + ret = fchownat(dirfd, name, credp->fc_uid, credp->fc_gid, + AT_SYMLINK_NOFOLLOW); } else if (fs_ctx->export_flags & V9FS_SM_MAPPED) { - buffer = rpath(fs_ctx, path); - ret = local_set_xattr(buffer, credp); - g_free(buffer); + ret = local_set_xattrat(dirfd, name, credp); } else if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE) { - return local_set_mapped_file_attr(fs_ctx, path, credp); + ret = local_set_mapped_file_attrat(dirfd, name, credp); } + + close_preserve_errno(dirfd); +out: + g_free(name); + g_free(dirpath); return ret; } static int local_utimensat(FsContext *s, V9fsPath *fs_path, const struct timespec *buf) { - char *buffer; - int ret; - char *path = fs_path->data; + char *dirpath = g_path_get_dirname(fs_path->data); + char *name = g_path_get_basename(fs_path->data); + int dirfd, ret = -1; + + dirfd = local_opendir_nofollow(s, dirpath); + if (dirfd == -1) { + goto out; + } - buffer = rpath(s, path); - ret = qemu_utimens(buffer, buf); - g_free(buffer); + ret = utimensat(dirfd, name, buf, AT_SYMLINK_NOFOLLOW); + close_preserve_errno(dirfd); +out: + g_free(dirpath); + g_free(name); return ret; } -static int local_remove(FsContext *ctx, const char *path) +static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name, + int flags) { - int err; - struct stat stbuf; - char *buffer; + int ret = -1; if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { - buffer = rpath(ctx, path); - err = lstat(buffer, &stbuf); - g_free(buffer); - if (err) { - goto err_out; - } - /* - * If directory remove .virtfs_metadata contained in the - * directory - */ - if (S_ISDIR(stbuf.st_mode)) { - buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, - path, VIRTFS_META_DIR); - err = remove(buffer); - g_free(buffer); - if (err < 0 && errno != ENOENT) { + int map_dirfd; + + if (flags == AT_REMOVEDIR) { + int fd; + + fd = openat(dirfd, name, O_RDONLY | O_DIRECTORY | O_PATH); + if (fd == -1) { + goto err_out; + } + /* + * If directory remove .virtfs_metadata contained in the + * directory + */ + ret = unlinkat(fd, VIRTFS_META_DIR, AT_REMOVEDIR); + close_preserve_errno(fd); + if (ret < 0 && errno != ENOENT) { /* * We didn't had the .virtfs_metadata file. May be file created * in non-mapped mode ?. Ignore ENOENT. @@ -972,12 +979,12 @@ static int local_remove(FsContext *ctx, const char *path) } /* * Now remove the name from parent directory - * .virtfs_metadata directory + * .virtfs_metadata directory. */ - buffer = local_mapped_attr_path(ctx, path); - err = remove(buffer); - g_free(buffer); - if (err < 0 && errno != ENOENT) { + map_dirfd = openat_dir(dirfd, VIRTFS_META_DIR); + ret = unlinkat(map_dirfd, name, 0); + close_preserve_errno(map_dirfd); + if (ret < 0 && errno != ENOENT) { /* * We didn't had the .virtfs_metadata file. May be file created * in non-mapped mode ?. Ignore ENOENT. @@ -986,10 +993,39 @@ static int local_remove(FsContext *ctx, const char *path) } } - buffer = rpath(ctx, path); - err = remove(buffer); - g_free(buffer); + ret = unlinkat(dirfd, name, flags); +err_out: + return ret; +} + +static int local_remove(FsContext *ctx, const char *path) +{ + struct stat stbuf; + char *dirpath = g_path_get_dirname(path); + char *name = g_path_get_basename(path); + int flags = 0; + int dirfd; + int err = -1; + + dirfd = local_opendir_nofollow(ctx, dirpath); + if (dirfd) { + goto out; + } + + if (fstatat(dirfd, path, &stbuf, AT_SYMLINK_NOFOLLOW) < 0) { + goto err_out; + } + + if (S_ISDIR(stbuf.st_mode)) { + flags |= AT_REMOVEDIR; + } + + err = local_unlinkat_common(ctx, dirfd, name, flags); err_out: + close_preserve_errno(dirfd); +out: + g_free(name); + g_free(dirpath); return err; } @@ -1013,13 +1049,11 @@ static int local_fsync(FsContext *ctx, int fid_type, static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) { - char *buffer; - int ret; - char *path = fs_path->data; + int fd, ret; - buffer = rpath(s, path); - ret = statfs(buffer, stbuf); - g_free(buffer); + fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0); + ret = fstatfs(fd, stbuf); + close_preserve_errno(fd); return ret; } @@ -1071,70 +1105,105 @@ static int local_renameat(FsContext *ctx, V9fsPath *olddir, const char *new_name) { int ret; - V9fsString old_full_name, new_full_name; + int odirfd, ndirfd; - v9fs_string_init(&old_full_name); - v9fs_string_init(&new_full_name); + odirfd = local_opendir_nofollow(ctx, olddir->data); + if (odirfd == -1) { + return -1; + } - v9fs_string_sprintf(&old_full_name, "%s/%s", olddir->data, old_name); - v9fs_string_sprintf(&new_full_name, "%s/%s", newdir->data, new_name); + ndirfd = local_opendir_nofollow(ctx, newdir->data); + if (ndirfd == -1) { + close_preserve_errno(odirfd); + return -1; + } - ret = local_rename(ctx, old_full_name.data, new_full_name.data); - v9fs_string_free(&old_full_name); - v9fs_string_free(&new_full_name); + ret = renameat(odirfd, old_name, ndirfd, new_name); + if (ret < 0) { + goto out; + } + + if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { + int omap_dirfd, nmap_dirfd; + + ret = mkdirat(ndirfd, VIRTFS_META_DIR, 0700); + if (ret < 0 && errno != EEXIST) { + goto err_undo_rename; + } + + omap_dirfd = openat_dir(odirfd, VIRTFS_META_DIR); + if (omap_dirfd == -1) { + goto err; + } + + nmap_dirfd = openat_dir(ndirfd, VIRTFS_META_DIR); + if (nmap_dirfd == -1) { + close_preserve_errno(omap_dirfd); + goto err; + } + + /* rename the .virtfs_metadata files */ + ret = renameat(omap_dirfd, old_name, nmap_dirfd, new_name); + close_preserve_errno(nmap_dirfd); + close_preserve_errno(omap_dirfd); + if (ret < 0 && errno != ENOENT) { + goto err_undo_rename; + } + + ret = 0; + } + goto out; + +err: + ret = -1; +err_undo_rename: + renameat_preserve_errno(ndirfd, new_name, odirfd, old_name); +out: + close_preserve_errno(ndirfd); + close_preserve_errno(odirfd); return ret; } +static void v9fs_path_init_dirname(V9fsPath *path, const char *str) +{ + path->data = g_path_get_dirname(str); + path->size = strlen(path->data) + 1; +} + +static int local_rename(FsContext *ctx, const char *oldpath, + const char *newpath) +{ + int err; + char *oname = g_path_get_basename(oldpath); + char *nname = g_path_get_basename(newpath); + V9fsPath olddir, newdir; + + v9fs_path_init_dirname(&olddir, oldpath); + v9fs_path_init_dirname(&newdir, newpath); + + err = local_renameat(ctx, &olddir, oname, &newdir, nname); + + v9fs_path_free(&newdir); + v9fs_path_free(&olddir); + g_free(nname); + g_free(oname); + + return err; +} + static int local_unlinkat(FsContext *ctx, V9fsPath *dir, const char *name, int flags) { int ret; - V9fsString fullname; - char *buffer; - - v9fs_string_init(&fullname); + int dirfd; - v9fs_string_sprintf(&fullname, "%s/%s", dir->data, name); - if (ctx->export_flags & V9FS_SM_MAPPED_FILE) { - if (flags == AT_REMOVEDIR) { - /* - * If directory remove .virtfs_metadata contained in the - * directory - */ - buffer = g_strdup_printf("%s/%s/%s", ctx->fs_root, - fullname.data, VIRTFS_META_DIR); - ret = remove(buffer); - g_free(buffer); - if (ret < 0 && errno != ENOENT) { - /* - * We didn't had the .virtfs_metadata file. May be file created - * in non-mapped mode ?. Ignore ENOENT. - */ - goto err_out; - } - } - /* - * Now remove the name from parent directory - * .virtfs_metadata directory. - */ - buffer = local_mapped_attr_path(ctx, fullname.data); - ret = remove(buffer); - g_free(buffer); - if (ret < 0 && errno != ENOENT) { - /* - * We didn't had the .virtfs_metadata file. May be file created - * in non-mapped mode ?. Ignore ENOENT. - */ - goto err_out; - } + dirfd = local_opendir_nofollow(ctx, dir->data); + if (dirfd == -1) { + return -1; } - /* Remove the name finally */ - buffer = rpath(ctx, fullname.data); - ret = remove(buffer); - g_free(buffer); -err_out: - v9fs_string_free(&fullname); + ret = local_unlinkat_common(ctx, dirfd, name, flags); + close_preserve_errno(dirfd); return ret; } @@ -1168,8 +1237,31 @@ static int local_ioc_getversion(FsContext *ctx, V9fsPath *path, static int local_init(FsContext *ctx) { - int err = 0; struct statfs stbuf; + LocalData *data = g_malloc(sizeof(*data)); + + data->mountfd = open(ctx->fs_root, O_DIRECTORY | O_RDONLY); + if (data->mountfd == -1) { + goto err; + } + +#ifdef FS_IOC_GETVERSION + /* + * use ioc_getversion only if the ioctl is definied + */ + if (fstatfs(data->mountfd, &stbuf) < 0) { + close_preserve_errno(data->mountfd); + goto err; + } + switch (stbuf.f_type) { + case EXT2_SUPER_MAGIC: + case BTRFS_SUPER_MAGIC: + case REISERFS_SUPER_MAGIC: + case XFS_SUPER_MAGIC: + ctx->exops.get_st_gen = local_ioc_getversion; + break; + } +#endif if (ctx->export_flags & V9FS_SM_PASSTHROUGH) { ctx->xops = passthrough_xattr_ops; @@ -1185,23 +1277,21 @@ static int local_init(FsContext *ctx) ctx->xops = passthrough_xattr_ops; } ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT; -#ifdef FS_IOC_GETVERSION - /* - * use ioc_getversion only if the iocl is definied - */ - err = statfs(ctx->fs_root, &stbuf); - if (!err) { - switch (stbuf.f_type) { - case EXT2_SUPER_MAGIC: - case BTRFS_SUPER_MAGIC: - case REISERFS_SUPER_MAGIC: - case XFS_SUPER_MAGIC: - ctx->exops.get_st_gen = local_ioc_getversion; - break; - } - } -#endif - return err; + + ctx->private = data; + return 0; + +err: + g_free(data); + return -1; +} + +static void local_cleanup(FsContext *ctx) +{ + LocalData *data = ctx->private; + + close(data->mountfd); + g_free(data); } static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse) @@ -1252,6 +1342,7 @@ static int local_parse_opts(QemuOpts *opts, struct FsDriverEntry *fse) FileOperations local_ops = { .parse_opts = local_parse_opts, .init = local_init, + .cleanup = local_cleanup, .lstat = local_lstat, .readlink = local_readlink, .close = local_close, diff --git a/hw/9pfs/9p-local.h b/hw/9pfs/9p-local.h new file mode 100644 index 0000000..32c7274 --- /dev/null +++ b/hw/9pfs/9p-local.h @@ -0,0 +1,20 @@ +/* + * 9p local backend utilities + * + * Copyright IBM, Corp. 2017 + * + * Authors: + * Greg Kurz <groug@kaod.org> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef QEMU_9P_LOCAL_H +#define QEMU_9P_LOCAL_H + +int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags, + mode_t mode); +int local_opendir_nofollow(FsContext *fs_ctx, const char *path); + +#endif diff --git a/hw/9pfs/9p-posix-acl.c b/hw/9pfs/9p-posix-acl.c index ec00318..bbf8906 100644 --- a/hw/9pfs/9p-posix-acl.c +++ b/hw/9pfs/9p-posix-acl.c @@ -25,13 +25,7 @@ static ssize_t mp_pacl_getxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size) { - char *buffer; - ssize_t ret; - - buffer = rpath(ctx, path); - ret = lgetxattr(buffer, MAP_ACL_ACCESS, value, size); - g_free(buffer); - return ret; + return local_getxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size); } static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path, @@ -56,23 +50,16 @@ static ssize_t mp_pacl_listxattr(FsContext *ctx, const char *path, static int mp_pacl_setxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size, int flags) { - char *buffer; - int ret; - - buffer = rpath(ctx, path); - ret = lsetxattr(buffer, MAP_ACL_ACCESS, value, size, flags); - g_free(buffer); - return ret; + return local_setxattr_nofollow(ctx, path, MAP_ACL_ACCESS, value, size, + flags); } static int mp_pacl_removexattr(FsContext *ctx, const char *path, const char *name) { int ret; - char *buffer; - buffer = rpath(ctx, path); - ret = lremovexattr(buffer, MAP_ACL_ACCESS); + ret = local_removexattr_nofollow(ctx, path, MAP_ACL_ACCESS); if (ret == -1 && errno == ENODATA) { /* * We don't get ENODATA error when trying to remove a @@ -82,20 +69,13 @@ static int mp_pacl_removexattr(FsContext *ctx, errno = 0; ret = 0; } - g_free(buffer); return ret; } static ssize_t mp_dacl_getxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size) { - char *buffer; - ssize_t ret; - - buffer = rpath(ctx, path); - ret = lgetxattr(buffer, MAP_ACL_DEFAULT, value, size); - g_free(buffer); - return ret; + return local_getxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size); } static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path, @@ -120,23 +100,16 @@ static ssize_t mp_dacl_listxattr(FsContext *ctx, const char *path, static int mp_dacl_setxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size, int flags) { - char *buffer; - int ret; - - buffer = rpath(ctx, path); - ret = lsetxattr(buffer, MAP_ACL_DEFAULT, value, size, flags); - g_free(buffer); - return ret; + return local_setxattr_nofollow(ctx, path, MAP_ACL_DEFAULT, value, size, + flags); } static int mp_dacl_removexattr(FsContext *ctx, const char *path, const char *name) { int ret; - char *buffer; - buffer = rpath(ctx, path); - ret = lremovexattr(buffer, MAP_ACL_DEFAULT); + ret = local_removexattr_nofollow(ctx, path, MAP_ACL_DEFAULT); if (ret == -1 && errno == ENODATA) { /* * We don't get ENODATA error when trying to remove a @@ -146,7 +119,6 @@ static int mp_dacl_removexattr(FsContext *ctx, errno = 0; ret = 0; } - g_free(buffer); return ret; } diff --git a/hw/9pfs/9p-util.c b/hw/9pfs/9p-util.c new file mode 100644 index 0000000..fdb4d57 --- /dev/null +++ b/hw/9pfs/9p-util.c @@ -0,0 +1,69 @@ +/* + * 9p utilities + * + * Copyright IBM, Corp. 2017 + * + * Authors: + * Greg Kurz <groug@kaod.org> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#include "qemu/osdep.h" +#include "qemu/xattr.h" +#include "9p-util.h" + +int relative_openat_nofollow(int dirfd, const char *path, int flags, + mode_t mode) +{ + int fd; + + fd = dup(dirfd); + if (fd == -1) { + return -1; + } + + while (*path) { + const char *c; + int next_fd; + char *head; + + /* Only relative paths without consecutive slashes */ + assert(path[0] != '/'); + + head = g_strdup(path); + c = strchr(path, '/'); + if (c) { + head[c - path] = 0; + next_fd = openat_dir(fd, head); + } else { + next_fd = openat_file(fd, head, flags, mode); + } + g_free(head); + if (next_fd == -1) { + close_preserve_errno(fd); + return -1; + } + close(fd); + fd = next_fd; + + if (!c) { + break; + } + path = c + 1; + } + + return fd; +} + +ssize_t fgetxattrat_nofollow(int dirfd, const char *filename, const char *name, + void *value, size_t size) +{ + char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename); + int ret; + + ret = lgetxattr(proc_path, name, value, size); + g_free(proc_path); + return ret; +} diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h new file mode 100644 index 0000000..091f3ce --- /dev/null +++ b/hw/9pfs/9p-util.h @@ -0,0 +1,54 @@ +/* + * 9p utilities + * + * Copyright IBM, Corp. 2017 + * + * Authors: + * Greg Kurz <groug@kaod.org> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ + +#ifndef QEMU_9P_UTIL_H +#define QEMU_9P_UTIL_H + +static inline void close_preserve_errno(int fd) +{ + int serrno = errno; + close(fd); + errno = serrno; +} + +static inline int openat_dir(int dirfd, const char *name) +{ + return openat(dirfd, name, O_DIRECTORY | O_RDONLY | O_PATH); +} + +static inline int openat_file(int dirfd, const char *name, int flags, + mode_t mode) +{ + int fd, serrno, ret; + + fd = openat(dirfd, name, flags | O_NOFOLLOW | O_NOCTTY | O_NONBLOCK, + mode); + if (fd == -1) { + return -1; + } + + serrno = errno; + /* O_NONBLOCK was only needed to open the file. Let's drop it. */ + ret = fcntl(fd, F_SETFL, flags); + assert(!ret); + errno = serrno; + return fd; +} + +int relative_openat_nofollow(int dirfd, const char *path, int flags, + mode_t mode); +ssize_t fgetxattrat_nofollow(int dirfd, const char *path, const char *name, + void *value, size_t size); +int fsetxattrat_nofollow(int dirfd, const char *path, const char *name, + void *value, size_t size, int flags); + +#endif diff --git a/hw/9pfs/9p-xattr-user.c b/hw/9pfs/9p-xattr-user.c index f87530c..2c90817 100644 --- a/hw/9pfs/9p-xattr-user.c +++ b/hw/9pfs/9p-xattr-user.c @@ -20,9 +20,6 @@ static ssize_t mp_user_getxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size) { - char *buffer; - ssize_t ret; - if (strncmp(name, "user.virtfs.", 12) == 0) { /* * Don't allow fetch of user.virtfs namesapce @@ -31,10 +28,7 @@ static ssize_t mp_user_getxattr(FsContext *ctx, const char *path, errno = ENOATTR; return -1; } - buffer = rpath(ctx, path); - ret = lgetxattr(buffer, name, value, size); - g_free(buffer); - return ret; + return local_getxattr_nofollow(ctx, path, name, value, size); } static ssize_t mp_user_listxattr(FsContext *ctx, const char *path, @@ -73,9 +67,6 @@ static ssize_t mp_user_listxattr(FsContext *ctx, const char *path, static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size, int flags) { - char *buffer; - int ret; - if (strncmp(name, "user.virtfs.", 12) == 0) { /* * Don't allow fetch of user.virtfs namesapce @@ -84,18 +75,12 @@ static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name, errno = EACCES; return -1; } - buffer = rpath(ctx, path); - ret = lsetxattr(buffer, name, value, size, flags); - g_free(buffer); - return ret; + return local_setxattr_nofollow(ctx, path, name, value, size, flags); } static int mp_user_removexattr(FsContext *ctx, const char *path, const char *name) { - char *buffer; - int ret; - if (strncmp(name, "user.virtfs.", 12) == 0) { /* * Don't allow fetch of user.virtfs namesapce @@ -104,10 +89,7 @@ static int mp_user_removexattr(FsContext *ctx, errno = EACCES; return -1; } - buffer = rpath(ctx, path); - ret = lremovexattr(buffer, name); - g_free(buffer); - return ret; + return local_removexattr_nofollow(ctx, path, name); } XattrOperations mapped_user_xattr = { diff --git a/hw/9pfs/9p-xattr.c b/hw/9pfs/9p-xattr.c index 5d8595e..eec160b 100644 --- a/hw/9pfs/9p-xattr.c +++ b/hw/9pfs/9p-xattr.c @@ -15,6 +15,8 @@ #include "9p.h" #include "fsdev/file-op-9p.h" #include "9p-xattr.h" +#include "9p-util.h" +#include "9p-local.h" static XattrOperations *get_xattr_operations(XattrOperations **h, @@ -58,6 +60,16 @@ ssize_t pt_listxattr(FsContext *ctx, const char *path, return name_size; } +static ssize_t flistxattrat_nofollow(int dirfd, const char *filename, + char *list, size_t size) +{ + char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename); + int ret; + + ret = llistxattr(proc_path, list, size); + g_free(proc_path); + return ret; +} /* * Get the list and pass to each layer to find out whether @@ -67,24 +79,37 @@ ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, void *value, size_t vsize) { ssize_t size = 0; - char *buffer; void *ovalue = value; XattrOperations *xops; char *orig_value, *orig_value_start; ssize_t xattr_len, parsed_len = 0, attr_len; + char *dirpath, *name; + int dirfd; /* Get the actual len */ - buffer = rpath(ctx, path); - xattr_len = llistxattr(buffer, value, 0); + dirpath = g_path_get_dirname(path); + dirfd = local_opendir_nofollow(ctx, dirpath); + g_free(dirpath); + if (dirfd == -1) { + return -1; + } + + name = g_path_get_basename(path); + xattr_len = flistxattrat_nofollow(dirfd, name, value, 0); if (xattr_len <= 0) { - g_free(buffer); + g_free(name); + close_preserve_errno(dirfd); return xattr_len; } /* Now fetch the xattr and find the actual size */ orig_value = g_malloc(xattr_len); - xattr_len = llistxattr(buffer, orig_value, xattr_len); - g_free(buffer); + xattr_len = flistxattrat_nofollow(dirfd, name, orig_value, xattr_len); + g_free(name); + close_preserve_errno(dirfd); + if (xattr_len < 0) { + return -1; + } /* store the orig pointer */ orig_value_start = orig_value; @@ -143,6 +168,135 @@ int v9fs_remove_xattr(FsContext *ctx, } +ssize_t local_getxattr_nofollow(FsContext *ctx, const char *path, + const char *name, void *value, size_t size) +{ + char *dirpath = g_path_get_dirname(path); + char *filename = g_path_get_basename(path); + int dirfd; + ssize_t ret = -1; + + dirfd = local_opendir_nofollow(ctx, dirpath); + if (dirfd == -1) { + goto out; + } + + ret = fgetxattrat_nofollow(dirfd, filename, name, value, size); + close_preserve_errno(dirfd); +out: + g_free(dirpath); + g_free(filename); + return ret; +} + +ssize_t pt_getxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size) +{ + return local_getxattr_nofollow(ctx, path, name, value, size); +} + +int fsetxattrat_nofollow(int dirfd, const char *filename, const char *name, + void *value, size_t size, int flags) +{ + char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename); + int ret; + + ret = lsetxattr(proc_path, name, value, size, flags); + g_free(proc_path); + return ret; +} + +ssize_t local_setxattr_nofollow(FsContext *ctx, const char *path, + const char *name, void *value, size_t size, + int flags) +{ + char *dirpath = g_path_get_dirname(path); + char *filename = g_path_get_basename(path); + int dirfd; + ssize_t ret = -1; + + dirfd = local_opendir_nofollow(ctx, dirpath); + if (dirfd == -1) { + goto out; + } + + ret = fsetxattrat_nofollow(dirfd, filename, name, value, size, flags); + close_preserve_errno(dirfd); +out: + g_free(dirpath); + g_free(filename); + return ret; +} + +int pt_setxattr(FsContext *ctx, const char *path, const char *name, void *value, + size_t size, int flags) +{ + return local_setxattr_nofollow(ctx, path, name, value, size, flags); +} + +static ssize_t fremovexattrat_nofollow(int dirfd, const char *filename, + const char *name) +{ + char *proc_path = g_strdup_printf("/proc/self/fd/%d/%s", dirfd, filename); + int ret; + + ret = lremovexattr(proc_path, name); + g_free(proc_path); + return ret; +} + +ssize_t local_removexattr_nofollow(FsContext *ctx, const char *path, + const char *name) +{ + char *dirpath = g_path_get_dirname(path); + char *filename = g_path_get_basename(path); + int dirfd; + ssize_t ret = -1; + + dirfd = local_opendir_nofollow(ctx, dirpath); + if (dirfd == -1) { + goto out; + } + + ret = fremovexattrat_nofollow(dirfd, filename, name); + close_preserve_errno(dirfd); +out: + g_free(dirpath); + g_free(filename); + return ret; +} + +int pt_removexattr(FsContext *ctx, const char *path, const char *name) +{ + return local_removexattr_nofollow(ctx, path, name); +} + +ssize_t notsup_getxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size) +{ + errno = ENOTSUP; + return -1; +} + +int notsup_setxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags) +{ + errno = ENOTSUP; + return -1; +} + +ssize_t notsup_listxattr(FsContext *ctx, const char *path, char *name, + void *value, size_t size) +{ + return 0; +} + +int notsup_removexattr(FsContext *ctx, const char *path, const char *name) +{ + errno = ENOTSUP; + return -1; +} + XattrOperations *mapped_xattr_ops[] = { &mapped_user_xattr, &mapped_pacl_xattr, diff --git a/hw/9pfs/9p-xattr.h b/hw/9pfs/9p-xattr.h index a853ea6..0d83996 100644 --- a/hw/9pfs/9p-xattr.h +++ b/hw/9pfs/9p-xattr.h @@ -29,6 +29,13 @@ typedef struct xattr_operations const char *path, const char *name); } XattrOperations; +ssize_t local_getxattr_nofollow(FsContext *ctx, const char *path, + const char *name, void *value, size_t size); +ssize_t local_setxattr_nofollow(FsContext *ctx, const char *path, + const char *name, void *value, size_t size, + int flags); +ssize_t local_removexattr_nofollow(FsContext *ctx, const char *path, + const char *name); extern XattrOperations mapped_user_xattr; extern XattrOperations passthrough_user_xattr; @@ -49,73 +56,21 @@ ssize_t v9fs_list_xattr(FsContext *ctx, const char *path, void *value, int v9fs_set_xattr(FsContext *ctx, const char *path, const char *name, void *value, size_t size, int flags); int v9fs_remove_xattr(FsContext *ctx, const char *path, const char *name); + 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) -{ - char *buffer; - ssize_t ret; - - buffer = rpath(ctx, path); - ret = lgetxattr(buffer, name, value, size); - g_free(buffer); - return ret; -} - -static inline int pt_setxattr(FsContext *ctx, const char *path, - const char *name, void *value, - size_t size, int flags) -{ - char *buffer; - int ret; - - buffer = rpath(ctx, path); - ret = lsetxattr(buffer, name, value, size, flags); - g_free(buffer); - return ret; -} - -static inline int pt_removexattr(FsContext *ctx, - const char *path, const char *name) -{ - char *buffer; - int ret; - - buffer = rpath(ctx, path); - ret = lremovexattr(path, name); - g_free(buffer); - return ret; -} - -static inline ssize_t notsup_getxattr(FsContext *ctx, const char *path, - const char *name, void *value, - size_t size) -{ - errno = ENOTSUP; - return -1; -} - -static inline int notsup_setxattr(FsContext *ctx, const char *path, - const char *name, void *value, - size_t size, int flags) -{ - errno = ENOTSUP; - return -1; -} - -static inline ssize_t notsup_listxattr(FsContext *ctx, const char *path, - char *name, void *value, size_t size) -{ - return 0; -} - -static inline int notsup_removexattr(FsContext *ctx, - const char *path, const char *name) -{ - errno = ENOTSUP; - return -1; -} +ssize_t pt_getxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size); +int pt_setxattr(FsContext *ctx, const char *path, const char *name, void *value, + size_t size, int flags); +int pt_removexattr(FsContext *ctx, const char *path, const char *name); + +ssize_t notsup_getxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size); +int notsup_setxattr(FsContext *ctx, const char *path, const char *name, + void *value, size_t size, int flags); +ssize_t notsup_listxattr(FsContext *ctx, const char *path, char *name, + void *value, size_t size); +int notsup_removexattr(FsContext *ctx, const char *path, const char *name); #endif diff --git a/hw/9pfs/Makefile.objs b/hw/9pfs/Makefile.objs index da0ae0c..32197e6 100644 --- a/hw/9pfs/Makefile.objs +++ b/hw/9pfs/Makefile.objs @@ -1,4 +1,4 @@ -common-obj-y = 9p.o +common-obj-y = 9p.o 9p-util.o common-obj-y += 9p-local.o 9p-xattr.o common-obj-y += 9p-xattr-user.o 9p-posix-acl.o common-obj-y += coth.o cofs.o codir.o cofile.o |