jail: don't always CLONE_NEWUTS

no -h => no CLONE_NEWUTS
-h "" => CLONE_NEWUTS
-h "newjailhostname" => CLONE_NEWUTS + sethostname

Signed-off-by: Etienne CHAMPETIER <champetier.etienne@gmail.com>

diff --git a/jail/jail.c b/jail/jail.c
index e425254..c442847 100644 (file)
--- a/jail/jail.c
+++ b/jail/jail.c
@@ -244,7 +244,7 @@ static int exec_jail(void *_notused)
                exit(EXIT_FAILURE);
        }
 
-       if (opts.namespace && opts.hostname
+       if (opts.namespace && opts.hostname && strlen(opts.hostname) > 0
                        && sethostname(opts.hostname, strlen(opts.hostname))) {
                ERROR("sethostname(%s) failed: %s\n", opts.hostname, strerror(errno));
                exit(EXIT_FAILURE);
@@ -386,9 +386,10 @@ int main(int argc, char **argv)
 
        uloop_init();
        if (opts.namespace) {
-               jail_process.pid = clone(exec_jail,
-                       child_stack + STACK_SIZE,
-                       CLONE_NEWUTS | CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | SIGCHLD, NULL);
+               int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | SIGCHLD;
+               if (opts.hostname)
+                       flags |= CLONE_NEWUTS;
+               jail_process.pid = clone(exec_jail, child_stack + STACK_SIZE, flags, NULL);
        } else {
                jail_process.pid = fork();
        }