5 files changed, 133 insertions, 17 deletions

diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
new file mode 100644
index 000000000000..ef2df1475b51
--- /dev/null
+++ b/include/net/cls_cgroup.h
@@ -0,0 +1,63 @@
+/*
+ * cls_cgroup.h                 Control Group Classifier
+ *
+ * Authors:     Thomas Graf <tgraf@suug.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#ifndef _NET_CLS_CGROUP_H
+#define _NET_CLS_CGROUP_H
+
+#include <linux/cgroup.h>
+#include <linux/hardirq.h>
+#include <linux/rcupdate.h>
+
+#ifdef CONFIG_CGROUPS
+struct cgroup_cls_state
+{
+        struct cgroup_subsys_state css;
+        u32 classid;
+};
+
+#ifdef CONFIG_NET_CLS_CGROUP
+static inline u32 task_cls_classid(struct task_struct *p)
+{
+        if (in_interrupt())
+                return 0;
+
+        return container_of(task_subsys_state(p, net_cls_subsys_id),
+                            struct cgroup_cls_state, css).classid;
+}
+#else
+extern int net_cls_subsys_id;
+
+static inline u32 task_cls_classid(struct task_struct *p)
+{
+        int id;
+        u32 classid;
+
+        if (in_interrupt())
+                return 0;
+
+        rcu_read_lock();
+        id = rcu_dereference(net_cls_subsys_id);
+        if (id >= 0)
+                classid = container_of(task_subsys_state(p, id),
+                                       struct cgroup_cls_state, css)->classid;
+        rcu_read_unlock();
+
+        return classid;
+}
+#endif
+#else
+static inline u32 task_cls_classid(struct task_struct *p)
+{
+        return 0;
+}
+#endif
+#endif  /* _NET_CLS_CGROUP_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index 5697caf8cc76..d24f382cb712 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -312,7 +312,7 @@ struct sock {
         void                    *sk_security;
 #endif
         __u32                   sk_mark;
-        /* XXX 4 bytes hole on 64 bit */
+        u32                     sk_classid;
         void                    (*sk_state_change)(struct sock *sk);
         void                    (*sk_data_ready)(struct sock *sk, int bytes);
         void                    (*sk_write_space)(struct sock *sk);
@@ -1074,6 +1074,14 @@ extern void *sock_kmalloc(struct sock *sk, int size,
 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
 extern void sk_send_sigurg(struct sock *sk);
 
+#ifdef CONFIG_CGROUPS
+extern void sock_update_classid(struct sock *sk);
+#else
+static inline void sock_update_classid(struct sock *sk)
+{
+}
+#endif
+
 /*
  * Functions to fill in entries in struct proto_ops when a protocol
  * does not implement a particular function.
diff --git a/net/core/sock.c b/net/core/sock.c
index bf88a167c8f2..a05ae7f9771e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -123,6 +123,7 @@
 #include <linux/net_tstamp.h>
 #include <net/xfrm.h>
 #include <linux/ipsec.h>
+#include <net/cls_cgroup.h>
 
 #include <linux/filter.h>
 
@@ -217,6 +218,11 @@ __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
 EXPORT_SYMBOL(sysctl_optmem_max);
 
+#if defined(CONFIG_CGROUPS) && !defined(CONFIG_NET_CLS_CGROUP)
+int net_cls_subsys_id = -1;
+EXPORT_SYMBOL_GPL(net_cls_subsys_id);
+#endif
+
 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
 {
         struct timeval tv;
@@ -1050,6 +1056,16 @@ static void sk_prot_free(struct proto *prot, struct sock *sk)
         module_put(owner);
 }
 
+#ifdef CONFIG_CGROUPS
+void sock_update_classid(struct sock *sk)
+{
+        u32 classid = task_cls_classid(current);
+
+        if (classid && classid != sk->sk_classid)
+                sk->sk_classid = classid;
+}
+#endif
+
 /**
  *      sk_alloc - All socket objects are allocated here
  *      @net: the applicable net namespace
@@ -1073,6 +1089,8 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
                 sock_lock_init(sk);
                 sock_net_set(sk, get_net(net));
                 atomic_set(&sk->sk_wmem_alloc, 1);
+
+                sock_update_classid(sk);
         }
 
         return sk;
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 221180384fd7..78ef2c5e130b 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -16,14 +16,11 @@
 #include <linux/errno.h>
 #include <linux/skbuff.h>
 #include <linux/cgroup.h>
+#include <linux/rcupdate.h>
 #include <net/rtnetlink.h>
 #include <net/pkt_cls.h>
-
-struct cgroup_cls_state
-{
-        struct cgroup_subsys_state css;
-        u32 classid;
-};
+#include <net/sock.h>
+#include <net/cls_cgroup.h>
 
 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
                                                struct cgroup *cgrp);
@@ -112,6 +109,10 @@ static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
         struct cls_cgroup_head *head = tp->root;
         u32 classid;
 
+        rcu_read_lock();
+        classid = task_cls_state(current)->classid;
+        rcu_read_unlock();
+
         /*
          * Due to the nature of the classifier it is required to ignore all
          * packets originating from softirq context as accessing `current'
@@ -122,12 +123,12 @@ static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
          * calls by looking at the number of nested bh disable calls because
          * softirqs always disables bh.
          */
-        if (softirq_count() != SOFTIRQ_OFFSET)
-                return -1;
-
-        rcu_read_lock();
-        classid = task_cls_state(current)->classid;
-        rcu_read_unlock();
+        if (softirq_count() != SOFTIRQ_OFFSET) {
+                /* If there is an sk_classid we'll use that. */
+                if (!skb->sk)
+                        return -1;
+                classid = skb->sk->sk_classid;
+        }
 
         if (!classid)
                 return -1;
@@ -289,18 +290,35 @@ static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
 
 static int __init init_cgroup_cls(void)
 {
-        int ret = register_tcf_proto_ops(&cls_cgroup_ops);
-        if (ret)
-                return ret;
+        int ret;
+
         ret = cgroup_load_subsys(&net_cls_subsys);
         if (ret)
-                unregister_tcf_proto_ops(&cls_cgroup_ops);
+                goto out;
+
+#ifndef CONFIG_NET_CLS_CGROUP
+        /* We can't use rcu_assign_pointer because this is an int. */
+        smp_wmb();
+        net_cls_subsys_id = net_cls_subsys.subsys_id;
+#endif
+
+        ret = register_tcf_proto_ops(&cls_cgroup_ops);
+        if (ret)
+                cgroup_unload_subsys(&net_cls_subsys);
+
+out:
         return ret;
 }
 
 static void __exit exit_cgroup_cls(void)
 {
         unregister_tcf_proto_ops(&cls_cgroup_ops);
+
+#ifndef CONFIG_NET_CLS_CGROUP
+        net_cls_subsys_id = -1;
+        synchronize_rcu();
+#endif
+
         cgroup_unload_subsys(&net_cls_subsys);
 }
 
diff --git a/net/socket.c b/net/socket.c
index f9f7d0872cac..367d5477d00f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -94,6 +94,7 @@
 
 #include <net/compat.h>
 #include <net/wext.h>
+#include <net/cls_cgroup.h>
 
 #include <net/sock.h>
 #include <linux/netfilter.h>
@@ -558,6 +559,8 @@ static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
         struct sock_iocb *si = kiocb_to_siocb(iocb);
         int err;
 
+        sock_update_classid(sock->sk);
+
         si->sock = sock;
         si->scm = NULL;
         si->msg = msg;
@@ -684,6 +687,8 @@ static inline int __sock_recvmsg_nosec(struct kiocb *iocb, struct socket *sock,
 {
         struct sock_iocb *si = kiocb_to_siocb(iocb);
 
+        sock_update_classid(sock->sk);
+
         si->sock = sock;
         si->scm = NULL;
         si->msg = msg;
@@ -777,6 +782,8 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos,
         if (unlikely(!sock->ops->splice_read))
                 return -EINVAL;
 
+        sock_update_classid(sock->sk);
+
         return sock->ops->splice_read(sock, ppos, pipe, len, flags);
 }
 
@@ -3069,6 +3076,8 @@ int kernel_setsockopt(struct socket *sock, int level, int optname,
 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
                     size_t size, int flags)
 {
+        sock_update_classid(sock->sk);
+
         if (sock->ops->sendpage)
                 return sock->ops->sendpage(sock, page, offset, size, flags);