core: introduce cgroup_add_device_allow()

(cherry picked from commit fd870bac25c2dd36affaed0251b5a7023f635306)

Related: #1763435

3 files changed, 32 insertions, 12 deletions

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 9d09c65453..a17b38f914 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -341,6 +341,35 @@ void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) {
         }
 }
 
+int cgroup_add_device_allow(CGroupContext *c, const char *dev, const char *mode) {
+        _cleanup_free_ CGroupDeviceAllow *a = NULL;
+        _cleanup_free_ char *d = NULL;
+
+        assert(c);
+        assert(dev);
+        assert(isempty(mode) || in_charset(mode, "rwm"));
+
+        a = new(CGroupDeviceAllow, 1);
+        if (!a)
+                return -ENOMEM;
+
+        d = strdup(dev);
+        if (!d)
+                return -ENOMEM;
+
+        *a = (CGroupDeviceAllow) {
+                .path = TAKE_PTR(d),
+                .r = isempty(mode) || !!strchr(mode, 'r'),
+                .w = isempty(mode) || !!strchr(mode, 'w'),
+                .m = isempty(mode) || !!strchr(mode, 'm'),
+        };
+
+        LIST_PREPEND(device_allow, c->device_allow, a);
+        TAKE_PTR(a);
+
+        return 0;
+}
+
 static int lookup_block_device(const char *p, dev_t *ret) {
         struct stat st;
         int r;
diff --git a/src/core/cgroup.h b/src/core/cgroup.h
index 5e1be87b20..8102b442b8 100644
--- a/src/core/cgroup.h
+++ b/src/core/cgroup.h
@@ -153,6 +153,8 @@ void cgroup_context_free_io_device_latency(CGroupContext *c, CGroupIODeviceLaten
 void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w);
 void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b);
 
+int cgroup_add_device_allow(CGroupContext *c, const char *dev, const char *mode);
+
 CGroupMask unit_get_own_mask(Unit *u);
 CGroupMask unit_get_delegate_mask(Unit *u);
 CGroupMask unit_get_members_mask(Unit *u);
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index d43b0f08f9..89a3457acc 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -3250,7 +3250,6 @@ int config_parse_device_allow(
 
         _cleanup_free_ char *path = NULL, *resolved = NULL;
         CGroupContext *c = data;
-        CGroupDeviceAllow *a;
         const char *p = rvalue;
         int r;
 
@@ -3299,17 +3298,7 @@ int config_parse_device_allow(
                 return 0;
         }
 
-        a = new0(CGroupDeviceAllow, 1);
-        if (!a)
-                return log_oom();
-
-        a->path = TAKE_PTR(resolved);
-        a->r = isempty(p) || !!strchr(p, 'r');
-        a->w = isempty(p) || !!strchr(p, 'w');
-        a->m = isempty(p) || !!strchr(p, 'm');
-
-        LIST_PREPEND(device_allow, c->device_allow, a);
-        return 0;
+        return cgroup_add_device_allow(c, resolved, p);
 }
 
 int config_parse_io_device_weight(