lzo: properly check for overruns
[linux-3.10.git] / lib / kobject_uevent.c
index 9fb6b86..52e5abb 100644 (file)
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/kobject.h>
-#include <linux/module.h>
-
+#include <linux/export.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/user_namespace.h>
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 #include <net/sock.h>
+#include <net/net_namespace.h>
 
 
 u64 uevent_seqnum;
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
-static DEFINE_SPINLOCK(sequence_lock);
-#if defined(CONFIG_NET)
-static struct sock *uevent_sock;
+#ifdef CONFIG_NET
+struct uevent_sock {
+       struct list_head list;
+       struct sock *sk;
+};
+static LIST_HEAD(uevent_sock_list);
 #endif
 
+/* This lock protects uevent_seqnum and uevent_sock_list */
+static DEFINE_MUTEX(uevent_sock_mutex);
+
 /* the strings here must match the enum in include/linux/kobject.h */
 static const char *kobject_actions[] = {
        [KOBJ_ADD] =            "add",
@@ -76,6 +85,39 @@ out:
        return ret;
 }
 
+#ifdef CONFIG_NET
+static int kobj_bcast_filter(struct sock *dsk, struct sk_buff *skb, void *data)
+{
+       struct kobject *kobj = data;
+       const struct kobj_ns_type_operations *ops;
+
+       ops = kobj_ns_ops(kobj);
+       if (ops) {
+               const void *sock_ns, *ns;
+               ns = kobj->ktype->namespace(kobj);
+               sock_ns = ops->netlink_ns(dsk);
+               return sock_ns != ns;
+       }
+
+       return 0;
+}
+#endif
+
+static int kobj_usermode_filter(struct kobject *kobj)
+{
+       const struct kobj_ns_type_operations *ops;
+
+       ops = kobj_ns_ops(kobj);
+       if (ops) {
+               const void *init_ns, *ns;
+               ns = kobj->ktype->namespace(kobj);
+               init_ns = ops->initial_ns();
+               return ns != init_ns;
+       }
+
+       return 0;
+}
+
 /**
  * kobject_uevent_env - send an uevent with environmental data
  *
@@ -83,7 +125,7 @@ out:
  * @kobj: struct kobject that the action is happening to
  * @envp_ext: pointer to environmental data
  *
- * Returns 0 if kobject_uevent() is completed with success or the
+ * Returns 0 if kobject_uevent_env() is completed with success or the
  * corresponding error when it fails.
  */
 int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
@@ -95,13 +137,15 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        const char *subsystem;
        struct kobject *top_kobj;
        struct kset *kset;
-       struct kset_uevent_ops *uevent_ops;
-       u64 seq;
+       const struct kset_uevent_ops *uevent_ops;
        int i = 0;
        int retval = 0;
+#ifdef CONFIG_NET
+       struct uevent_sock *ue_sk;
+#endif
 
        pr_debug("kobject: '%s' (%p): %s\n",
-                kobject_name(kobj), kobj, __FUNCTION__);
+                kobject_name(kobj), kobj, __func__);
 
        /* search the kset we belong to */
        top_kobj = kobj;
@@ -111,19 +155,26 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        if (!top_kobj->kset) {
                pr_debug("kobject: '%s' (%p): %s: attempted to send uevent "
                         "without kset!\n", kobject_name(kobj), kobj,
-                        __FUNCTION__);
+                        __func__);
                return -EINVAL;
        }
 
        kset = top_kobj->kset;
        uevent_ops = kset->uevent_ops;
 
+       /* skip the event, if uevent_suppress is set*/
+       if (kobj->uevent_suppress) {
+               pr_debug("kobject: '%s' (%p): %s: uevent_suppress "
+                                "caused the event to drop!\n",
+                                kobject_name(kobj), kobj, __func__);
+               return 0;
+       }
        /* skip the event, if the filter returns zero. */
        if (uevent_ops && uevent_ops->filter)
                if (!uevent_ops->filter(kset, kobj)) {
                        pr_debug("kobject: '%s' (%p): %s: filter function "
                                 "caused the event to drop!\n",
-                                kobject_name(kobj), kobj, __FUNCTION__);
+                                kobject_name(kobj), kobj, __func__);
                        return 0;
                }
 
@@ -135,7 +186,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        if (!subsystem) {
                pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the "
                         "event to drop!\n", kobject_name(kobj), kobj,
-                        __FUNCTION__);
+                        __func__);
                return 0;
        }
 
@@ -165,7 +216,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        /* keys passed in from the caller */
        if (envp_ext) {
                for (i = 0; envp_ext[i]; i++) {
-                       retval = add_uevent_var(env, envp_ext[i]);
+                       retval = add_uevent_var(env, "%s", envp_ext[i]);
                        if (retval)
                                goto exit;
                }
@@ -177,7 +228,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                if (retval) {
                        pr_debug("kobject: '%s' (%p): %s: uevent() returned "
                                 "%d\n", kobject_name(kobj), kobj,
-                                __FUNCTION__, retval);
+                                __func__, retval);
                        goto exit;
                }
        }
@@ -193,20 +244,24 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        else if (action == KOBJ_REMOVE)
                kobj->state_remove_uevent_sent = 1;
 
+       mutex_lock(&uevent_sock_mutex);
        /* we will send an event, so request a new sequence number */
-       spin_lock(&sequence_lock);
-       seq = ++uevent_seqnum;
-       spin_unlock(&sequence_lock);
-       retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)seq);
-       if (retval)
+       retval = add_uevent_var(env, "SEQNUM=%llu", (unsigned long long)++uevent_seqnum);
+       if (retval) {
+               mutex_unlock(&uevent_sock_mutex);
                goto exit;
+       }
 
 #if defined(CONFIG_NET)
        /* send netlink message */
-       if (uevent_sock) {
+       list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+               struct sock *uevent_sock = ue_sk->sk;
                struct sk_buff *skb;
                size_t len;
 
+               if (!netlink_has_listeners(uevent_sock, 1))
+                       continue;
+
                /* allocate message with the maximum possible size */
                len = strlen(action_string) + strlen(devpath) + 2;
                skb = alloc_skb(len + env->buflen, GFP_KERNEL);
@@ -225,13 +280,21 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                        }
 
                        NETLINK_CB(skb).dst_group = 1;
-                       netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL);
-               }
+                       retval = netlink_broadcast_filtered(uevent_sock, skb,
+                                                           0, 1, GFP_KERNEL,
+                                                           kobj_bcast_filter,
+                                                           kobj);
+                       /* ENOBUFS should be handled in userspace */
+                       if (retval == -ENOBUFS || retval == -ESRCH)
+                               retval = 0;
+               } else
+                       retval = -ENOMEM;
        }
 #endif
+       mutex_unlock(&uevent_sock_mutex);
 
        /* call uevent_helper, usually only enabled during early boot */
-       if (uevent_helper[0]) {
+       if (uevent_helper[0] && !kobj_usermode_filter(kobj)) {
                char *argv [3];
 
                argv [0] = uevent_helper;
@@ -245,7 +308,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                if (retval)
                        goto exit;
 
-               call_usermodehelper(argv[0], argv, env->envp, UMH_WAIT_EXEC);
+               retval = call_usermodehelper(argv[0], argv,
+                                            env->envp, UMH_WAIT_EXEC);
        }
 
 exit:
@@ -256,7 +320,7 @@ exit:
 EXPORT_SYMBOL_GPL(kobject_uevent_env);
 
 /**
- * kobject_uevent - notify userspace by ending an uevent
+ * kobject_uevent - notify userspace by sending an uevent
  *
  * @action: action that is happening
  * @kobj: struct kobject that the action is happening to
@@ -284,8 +348,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
        int len;
 
        if (env->envp_idx >= ARRAY_SIZE(env->envp)) {
-               printk(KERN_ERR "add_uevent_var: too many keys\n");
-               WARN_ON(1);
+               WARN(1, KERN_ERR "add_uevent_var: too many keys\n");
                return -ENOMEM;
        }
 
@@ -296,8 +359,7 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
        va_end(args);
 
        if (len >= (sizeof(env->buf) - env->buflen)) {
-               printk(KERN_ERR "add_uevent_var: buffer size too small\n");
-               WARN_ON(1);
+               WARN(1, KERN_ERR "add_uevent_var: buffer size too small\n");
                return -ENOMEM;
        }
 
@@ -308,18 +370,61 @@ int add_uevent_var(struct kobj_uevent_env *env, const char *format, ...)
 EXPORT_SYMBOL_GPL(add_uevent_var);
 
 #if defined(CONFIG_NET)
-static int __init kobject_uevent_init(void)
+static int uevent_net_init(struct net *net)
 {
-       uevent_sock = netlink_kernel_create(&init_net, NETLINK_KOBJECT_UEVENT,
-                                           1, NULL, NULL, THIS_MODULE);
-       if (!uevent_sock) {
+       struct uevent_sock *ue_sk;
+       struct netlink_kernel_cfg cfg = {
+               .groups = 1,
+               .flags  = NL_CFG_F_NONROOT_RECV,
+       };
+
+       ue_sk = kzalloc(sizeof(*ue_sk), GFP_KERNEL);
+       if (!ue_sk)
+               return -ENOMEM;
+
+       ue_sk->sk = netlink_kernel_create(net, NETLINK_KOBJECT_UEVENT, &cfg);
+       if (!ue_sk->sk) {
                printk(KERN_ERR
                       "kobject_uevent: unable to create netlink socket!\n");
+               kfree(ue_sk);
                return -ENODEV;
        }
-
+       mutex_lock(&uevent_sock_mutex);
+       list_add_tail(&ue_sk->list, &uevent_sock_list);
+       mutex_unlock(&uevent_sock_mutex);
        return 0;
 }
 
+static void uevent_net_exit(struct net *net)
+{
+       struct uevent_sock *ue_sk;
+
+       mutex_lock(&uevent_sock_mutex);
+       list_for_each_entry(ue_sk, &uevent_sock_list, list) {
+               if (sock_net(ue_sk->sk) == net)
+                       goto found;
+       }
+       mutex_unlock(&uevent_sock_mutex);
+       return;
+
+found:
+       list_del(&ue_sk->list);
+       mutex_unlock(&uevent_sock_mutex);
+
+       netlink_kernel_release(ue_sk->sk);
+       kfree(ue_sk);
+}
+
+static struct pernet_operations uevent_net_ops = {
+       .init   = uevent_net_init,
+       .exit   = uevent_net_exit,
+};
+
+static int __init kobject_uevent_init(void)
+{
+       return register_pernet_subsys(&uevent_net_ops);
+}
+
+
 postcore_initcall(kobject_uevent_init);
 #endif