systemd/0009-namespace-fall-back-gr...

124 lines
4.4 KiB
Diff

From aad46f8f761dfe93954ebba2cd764c4530337083 Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekletar@users.noreply.github.com>
Date: Tue, 10 Oct 2017 09:46:13 +0200
Subject: [PATCH] namespace: fall back gracefully when kernel doesn't support
network namespaces (#7024)
(cherry picked from commit 6e2d7c4f131edb19255842cdd4dc199cf8adb5ab)
---
TODO | 3 ---
src/core/execute.c | 13 ++++++++-----
src/core/namespace.c | 24 ++++++++++++++++++++++++
src/core/namespace.h | 17 +++++++++++++++++
4 files changed, 49 insertions(+), 8 deletions(-)
diff --git a/TODO b/TODO
index 81f009918c..020bdae9c8 100644
--- a/TODO
+++ b/TODO
@@ -115,9 +115,6 @@ Features:
* maybe introduce gpt auto discovery for /var/tmp?
-* fix PrivateNetwork= so that we fall back gracefully on kernels lacking
- namespacing support (similar for the other namespacing options)
-
* maybe add gpt-partition-based user management: each user gets his own
LUKS-encrypted GPT partition with a new GPT type. A small nss module
enumerates users via udev partition enumeration. UIDs are assigned in a fixed
diff --git a/src/core/execute.c b/src/core/execute.c
index 2453f84fbd..ef95a75e75 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -3070,11 +3070,14 @@ static int exec_child(
}
if (context->private_network && runtime && runtime->netns_storage_socket[0] >= 0) {
- r = setup_netns(runtime->netns_storage_socket);
- if (r < 0) {
- *exit_status = EXIT_NETWORK;
- return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m");
- }
+ if (ns_type_supported(NAMESPACE_NET)) {
+ r = setup_netns(runtime->netns_storage_socket);
+ if (r < 0) {
+ *exit_status = EXIT_NETWORK;
+ return log_unit_error_errno(unit, r, "Failed to set up network namespacing: %m");
+ }
+ } else
+ log_unit_warning(unit, "PrivateNetwork=yes is configured, but the kernel does not support network namespaces, ignoring.");
}
needs_mount_namespace = exec_needs_mount_namespace(context, params, runtime);
diff --git a/src/core/namespace.c b/src/core/namespace.c
index 6d74b8da67..df32d666bf 100644
--- a/src/core/namespace.c
+++ b/src/core/namespace.c
@@ -1428,6 +1428,18 @@ fail:
return r;
}
+bool ns_type_supported(NamespaceType type) {
+ const char *t, *ns_proc;
+
+ if (type <= _NAMESPACE_TYPE_INVALID || type >= _NAMESPACE_TYPE_MAX)
+ return false;
+
+ t = namespace_type_to_string(type);
+ ns_proc = strjoina("/proc/self/ns/", t);
+
+ return access(ns_proc, F_OK) == 0;
+}
+
static const char *const protect_home_table[_PROTECT_HOME_MAX] = {
[PROTECT_HOME_NO] = "no",
[PROTECT_HOME_YES] = "yes",
@@ -1444,3 +1456,15 @@ static const char *const protect_system_table[_PROTECT_SYSTEM_MAX] = {
};
DEFINE_STRING_TABLE_LOOKUP(protect_system, ProtectSystem);
+
+static const char* const namespace_type_table[] = {
+ [NAMESPACE_MOUNT] = "mnt",
+ [NAMESPACE_CGROUP] = "cgroup",
+ [NAMESPACE_UTS] = "uts",
+ [NAMESPACE_IPC] = "ipc",
+ [NAMESPACE_USER] = "user",
+ [NAMESPACE_PID] = "pid",
+ [NAMESPACE_NET] = "net",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(namespace_type, NamespaceType);
diff --git a/src/core/namespace.h b/src/core/namespace.h
index da8d85dbc5..b244c8f337 100644
--- a/src/core/namespace.h
+++ b/src/core/namespace.h
@@ -36,6 +36,18 @@ typedef enum ProtectHome {
_PROTECT_HOME_INVALID = -1
} ProtectHome;
+typedef enum NamespaceType {
+ NAMESPACE_MOUNT,
+ NAMESPACE_CGROUP,
+ NAMESPACE_UTS,
+ NAMESPACE_IPC,
+ NAMESPACE_USER,
+ NAMESPACE_PID,
+ NAMESPACE_NET,
+ _NAMESPACE_TYPE_MAX,
+ _NAMESPACE_TYPE_INVALID = -1,
+} NamespaceType;
+
typedef enum ProtectSystem {
PROTECT_SYSTEM_NO,
PROTECT_SYSTEM_YES,
@@ -94,3 +106,8 @@ ProtectSystem protect_system_from_string(const char *s) _pure_;
void bind_mount_free_many(BindMount *b, unsigned n);
int bind_mount_add(BindMount **b, unsigned *n, const BindMount *item);
+
+const char* namespace_type_to_string(NamespaceType t) _const_;
+NamespaceType namespace_type_from_string(const char *s) _pure_;
+
+bool ns_type_supported(NamespaceType type);