--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+
+ POSIX NTVFS backend - pvfs_sys wrappers
+
+ Copyright (C) Andrew Tridgell 2010
+ Copyright (C) Andrew Bartlett 2010
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "vfs_posix.h"
+#include "../lib/util/unix_privs.h"
+
+/*
+ these wrapper functions must only be called when the appropriate ACL
+ has already been checked. The wrappers will override a EACCES result
+ by gaining root privileges if the 'pvfs:perm override' is set on the
+ share (it is enabled by default)
+ */
+
+
+/*
+ chown a file that we created with a root privileges override
+ */
+static int pvfs_sys_fchown(struct pvfs_state *pvfs, void *privs, int fd)
+{
+ return fchown(fd, root_privileges_original_uid(privs), -1);
+}
+
+/*
+ chown a directory that we created with a root privileges override
+ */
+static int pvfs_sys_chown(struct pvfs_state *pvfs, void *privs, const char *name)
+{
+ return chown(name, root_privileges_original_uid(privs), -1);
+}
+
+
+/*
+ wrap open for system override
+*/
+int pvfs_sys_open(struct pvfs_state *pvfs, const char *filename, int flags, mode_t mode)
+{
+ int fd, ret;
+ void *privs;
+ int saved_errno, orig_errno;
+ int retries = 5;
+
+ orig_errno = errno;
+
+ fd = open(filename, flags, mode);
+ if (fd != -1 ||
+ !(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
+ errno != EACCES) {
+ return fd;
+ }
+
+ saved_errno = errno;
+ privs = root_privileges();
+
+ /* don't allow permission overrides to follow links */
+#ifdef O_NOFOLLOW
+ flags |= O_NOFOLLOW;
+#endif
+
+ /*
+ if O_CREAT was specified and O_EXCL was not specified
+ then initially do the open without O_CREAT, as in that case
+ we know that we did not create the file, so we don't have
+ to fchown it
+ */
+ if ((flags & O_CREAT) && !(flags & O_EXCL)) {
+ try_again:
+ fd = open(filename, flags & ~O_CREAT, mode);
+ /* if this open succeeded, or if it failed
+ with anything other than ENOENT, then we return the
+ open result, with the original errno */
+ if (fd == -1 && errno != ENOENT) {
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+ if (fd != -1) {
+ /* the file already existed and we opened it */
+ talloc_free(privs);
+ errno = orig_errno;
+ return fd;
+ }
+
+ fd = open(filename, flags | O_EXCL, mode);
+ if (fd == -1 && errno != EEXIST) {
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+ if (fd != -1) {
+ /* we created the file, we need to set the
+ right ownership on it */
+ ret = pvfs_sys_fchown(pvfs, privs, fd);
+ if (ret == -1) {
+ close(fd);
+ unlink(filename);
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+ talloc_free(privs);
+ errno = orig_errno;
+ return fd;
+ }
+
+ /* the file got created between the two times
+ we tried to open it! Try again */
+ if (retries-- > 0) {
+ goto try_again;
+ }
+
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+
+ fd = open(filename, flags, mode);
+ if (fd == -1) {
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+
+ /* if we have created a file then fchown it */
+ if (flags & O_CREAT) {
+ ret = pvfs_sys_fchown(pvfs, privs, fd);
+ if (ret == -1) {
+ close(fd);
+ unlink(filename);
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+ }
+
+ talloc_free(privs);
+ return fd;
+}
+
+
+/*
+ wrap unlink for system override
+*/
+int pvfs_sys_unlink(struct pvfs_state *pvfs, const char *filename)
+{
+ int ret;
+ void *privs;
+ int saved_errno, orig_errno;
+
+ orig_errno = errno;
+
+ ret = unlink(filename);
+ if (ret != -1 ||
+ !(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
+ errno != EACCES) {
+ return ret;
+ }
+
+ saved_errno = errno;
+
+ privs = root_privileges();
+ ret = unlink(filename);
+ if (ret == -1) {
+ errno = saved_errno;
+ talloc_free(privs);
+ return -1;
+ }
+
+ errno = orig_errno;
+ talloc_free(privs);
+ return ret;
+}
+
+
+/*
+ wrap rename for system override
+*/
+int pvfs_sys_rename(struct pvfs_state *pvfs, const char *name1, const char *name2)
+{
+ int ret;
+ void *privs;
+ int saved_errno, orig_errno;
+
+ orig_errno = errno;
+
+ ret = rename(name1, name2);
+ if (ret != -1 ||
+ !(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
+ errno != EACCES) {
+ return ret;
+ }
+
+ saved_errno = errno;
+
+ privs = root_privileges();
+ ret = rename(name1, name2);
+ if (ret == -1) {
+ errno = saved_errno;
+ talloc_free(privs);
+ return -1;
+ }
+
+ errno = orig_errno;
+ talloc_free(privs);
+ return ret;
+}
+
+
+/*
+ wrap mkdir for system override
+*/
+int pvfs_sys_mkdir(struct pvfs_state *pvfs, const char *dirname, mode_t mode)
+{
+ int ret;
+ void *privs;
+ int saved_errno, orig_errno;
+
+ orig_errno = errno;
+
+ ret = mkdir(dirname, mode);
+ if (ret != -1 ||
+ !(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
+ errno != EACCES) {
+ return ret;
+ }
+
+ saved_errno = errno;
+ privs = root_privileges();
+
+ ret = mkdir(dirname, mode);
+ if (ret == -1) {
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+
+ ret = pvfs_sys_chown(pvfs, privs, dirname);
+ if (ret == -1) {
+ rmdir(dirname);
+ talloc_free(privs);
+ errno = saved_errno;
+ return -1;
+ }
+
+ talloc_free(privs);
+ return ret;
+}
+
+
+/*
+ wrap rmdir for system override
+*/
+int pvfs_sys_rmdir(struct pvfs_state *pvfs, const char *dirname)
+{
+ int ret;
+ void *privs;
+ int saved_errno, orig_errno;
+
+ orig_errno = errno;
+
+ ret = rmdir(dirname);
+ if (ret != -1 ||
+ !(pvfs->flags & PVFS_FLAG_PERM_OVERRIDE) ||
+ errno != EACCES) {
+ return ret;
+ }
+
+ saved_errno = errno;
+
+ privs = root_privileges();
+ ret = rmdir(dirname);
+ if (ret == -1) {
+ errno = saved_errno;
+ talloc_free(privs);
+ return -1;
+ }
+
+ errno = orig_errno;
+ talloc_free(privs);
+ return ret;
+}
projects / thirdparty / samba.git / commitdiff
