diff options
Diffstat (limited to 'hw/9pfs')
-rw-r--r-- | hw/9pfs/9p-util.c | 57 | ||||
-rw-r--r-- | hw/9pfs/9p-util.h | 50 | ||||
-rw-r--r-- | hw/9pfs/Makefile.objs | 2 |
3 files changed, 108 insertions, 1 deletions
diff --git a/hw/9pfs/9p-util.c b/hw/9pfs/9p-util.c new file mode 100644 index 0000000..54134b0 --- /dev/null +++ b/hw/9pfs/9p-util.c @@ -0,0 +1,57 @@ +/* + * 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 "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; +} diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h new file mode 100644 index 0000000..e80b5a5 --- /dev/null +++ b/hw/9pfs/9p-util.h @@ -0,0 +1,50 @@ +/* + * 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); + +#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 |