uevent: add alloc_uevent_skb() helper

This patch adds alloc_uevent_skb() in preparation for follow up patches.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 15ea216a67ce63128809320bb640057a41de76c6..649bf60a9440f5b206ac8f7c0289ee0ad3984de9 100644 (file)
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -22,6 +22,7 @@
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
+#include <linux/uidgid.h>
 #include <linux/uuid.h>
 #include <linux/ctype.h>
 #include <net/sock.h>
@@ -296,6 +297,38 @@ static void cleanup_uevent_env(struct subprocess_info *info)
 }
 #endif
 
+#ifdef CONFIG_NET
+static struct sk_buff *alloc_uevent_skb(struct kobj_uevent_env *env,
+                                       const char *action_string,
+                                       const char *devpath)
+{
+       struct netlink_skb_parms *parms;
+       struct sk_buff *skb = NULL;
+       char *scratch;
+       size_t len;
+
+       /* allocate message with maximum possible size */
+       len = strlen(action_string) + strlen(devpath) + 2;
+       skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+       if (!skb)
+               return NULL;
+
+       /* add header */
+       scratch = skb_put(skb, len);
+       sprintf(scratch, "%s@%s", action_string, devpath);
+
+       skb_put_data(skb, env->buf, env->buflen);
+
+       parms = &NETLINK_CB(skb);
+       parms->creds.uid = GLOBAL_ROOT_UID;
+       parms->creds.gid = GLOBAL_ROOT_GID;
+       parms->dst_group = 1;
+       parms->portid = 0;
+
+       return skb;
+}
+#endif
+
 static int kobject_uevent_net_broadcast(struct kobject *kobj,
                                        struct kobj_uevent_env *env,
                                        const char *action_string,
@@ -314,22 +347,10 @@ static int kobject_uevent_net_broadcast(struct kobject *kobj,
                        continue;
 
                if (!skb) {
-                       /* allocate message with the maximum possible size */
-                       size_t len = strlen(action_string) + strlen(devpath) + 2;
-                       char *scratch;
-
                        retval = -ENOMEM;
-                       skb = alloc_skb(len + env->buflen, GFP_KERNEL);
+                       skb = alloc_uevent_skb(env, action_string, devpath);
                        if (!skb)
                                continue;
-
-                       /* add header */
-                       scratch = skb_put(skb, len);
-                       sprintf(scratch, "%s@%s", action_string, devpath);
-
-                       skb_put_data(skb, env->buf, env->buflen);
-
-                       NETLINK_CB(skb).dst_group = 1;
                }
 
                retval = netlink_broadcast_filtered(uevent_sock, skb_get(skb),