systemd/0001-nspawn-create-empty-etc-resolv.conf-if-necessary.patch

59 lines
2.1 KiB
Diff
Raw Normal View History

From f333fbb1efc2f32527f78cbdb003d59bae01aa07 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Wed, 17 Apr 2013 14:13:09 -0400
Subject: [PATCH] nspawn: create empty /etc/resolv.conf if necessary
nspawn will overmount resolv.conf if it exists. Since e.g.
default install with yum doesn't create /etc/resolv.conf,
a container created with yum will not have network. This
seems undesirable, and since we overmount the file anyway,
let's create it too.
Also, mounting a read-write /etc/resolv.conf in the container
is treated as a failure, since it makes it possible to
modify hosts /etc/resolv.conf from inside the container.
---
src/nspawn/nspawn.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index f57c75f..5a43d5e 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -492,7 +492,8 @@ static int setup_timezone(const char *dest) {
}
static int setup_resolv_conf(const char *dest) {
- char *where;
+ char _cleanup_free_ *where = NULL;
+ _cleanup_close_ int fd = -1;
assert(dest);
@@ -504,12 +505,18 @@ static int setup_resolv_conf(const char *dest) {
if (!where)
return log_oom();
+ fd = open(where, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644);
+
/* We don't really care for the results of this really. If it
* fails, it fails, but meh... */
- if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) >= 0)
- mount("/etc/resolv.conf", where, "bind", MS_BIND|MS_REMOUNT|MS_RDONLY, NULL);
-
- free(where);
+ if (mount("/etc/resolv.conf", where, "bind", MS_BIND, NULL) < 0)
+ log_warning("Failed to bind mount /etc/resolv.conf: %m");
+ else
+ if (mount("/etc/resolv.conf", where, "bind",
+ MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
+ log_error("Failed to remount /etc/resolv.conf readonly: %m");
+ return -errno;
+ }
return 0;
}
--
1.8.2