Quoting Laine Stump (laine@xxxxxxxxx):
> These functions create a new file or directory with the given
> uid/gid. If the flag VIR_FILE_CREATE_AS_UID is given, they do this by
> forking a new process, calling setuid/setgid in the new process, and
> then creating the file. This is better than simply calling open then
> fchown, because in the latter case, a root-squashing nfs server would
> create the new file as user nobody, then refuse to allow fchown.
>
> If VIR_FILE_CREATE_AS_UID is not specified, the simpler tactic of
> creating the file/dir, then chowning is is used. This gives better
> results in cases where the parent directory isn't on a root-squashing
> NFS server, but doesn't give permission for the specified uid/gid to
> create files. (Note that if the fork/setuid method fails to create the
> file due to access privileges, the parent process will make a second
> attempt using this simpler method.)
>
> Return from both of these functions is 0 on success, or the value of
> errno if there was a failure.
> ---
> src/util/util.c | 247 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> src/util/util.h | 9 ++
> 2 files changed, 256 insertions(+), 0 deletions(-)
>
> diff --git a/src/util/util.c b/src/util/util.c
> index 1d493de..1cb29f4 100644
> --- a/src/util/util.c
> +++ b/src/util/util.c
> @@ -1126,6 +1126,253 @@ int virFileExists(const char *path)
> return(0);
> }
>
> +
> +static int virFileCreateSimple(const char *path, mode_t mode, uid_t uid, gid_t gid) {
> + int fd = -1;
> + int ret = 0;
> +
> + if ((fd = open(path, O_RDWR | O_CREAT | O_EXCL, mode)) < 0) {
> + ret = errno;
> + virReportSystemError(NULL, errno, _("failed to create file '%s'"),
> + path);
> + goto error;
> + }
> + if ((getuid() == 0) && ((uid != 0) || (gid != 0))) {
How about checking for CAP_CHOWN instead of getuid()==0? Otherwise
if I try installing this certain ways, virFileCreateSimple() will refuse
to try the chown even though it could succeed.
-serge
--
Libvir-list mailing list
Libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list