net: net_cls: move cgroupfs classid handling into core

Zefan Li requested [1] to perform the following cleanup/refactoring:

- Split cgroupfs classid handling into net core to better express a
  possible more generic use.

- Disable module support for cgroupfs bits as the majority of other
  cgroupfs subsystems do not have that, and seems to be not wished
  from cgroup side. Zefan probably might want to follow-up for netprio
  later on.

- By this, code can be further reduced which previously took care of
  functionality built when compiled as module.

cgroupfs bits are being placed under net/core/netclassid_cgroup.c, so
that we are consistent with {netclassid,netprio}_cgroup naming that is
under net/core/ as suggested by Zefan.

No change in functionality, but only code refactoring that is being
done here.

 [1] http://patchwork.ozlabs.org/patch/304825/

Suggested-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: cgroups@vger.kernel.org
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index b613ffd402d1bdd38747e45e26260b28a4355768..58bf94de4b8e812732362a02d69e3f2e9ef6b2c8 100644 (file)
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -31,7 +31,7 @@ SUBSYS(devices)
 SUBSYS(freezer)
 #endif
 
-#if IS_SUBSYS_ENABLED(CONFIG_NET_CLS_CGROUP)
+#if IS_SUBSYS_ENABLED(CONFIG_CGROUP_NET_CLASSID)
 SUBSYS(net_cls)
 #endif
 

diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h
index 33d03b648646ce04114c73c65853a0b19b548fa4..9cf2d5ef38d967ad7d67202bbd82f3bd933a31dd 100644 (file)
--- a/include/net/cls_cgroup.h
+++ b/include/net/cls_cgroup.h
@@ -16,17 +16,16 @@
 #include <linux/cgroup.h>
 #include <linux/hardirq.h>
 #include <linux/rcupdate.h>
+#include <net/sock.h>
 
-#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
-struct cgroup_cls_state
-{
+#ifdef CONFIG_CGROUP_NET_CLASSID
+struct cgroup_cls_state {
        struct cgroup_subsys_state css;
        u32 classid;
 };
 
-void sock_update_classid(struct sock *sk);
+struct cgroup_cls_state *task_cls_state(struct task_struct *p);
 
-#if IS_BUILTIN(CONFIG_NET_CLS_CGROUP)
 static inline u32 task_cls_classid(struct task_struct *p)
 {
        u32 classid;
@@ -41,33 +40,18 @@ static inline u32 task_cls_classid(struct task_struct *p)
 
        return classid;
 }
-#elif IS_MODULE(CONFIG_NET_CLS_CGROUP)
-static inline u32 task_cls_classid(struct task_struct *p)
-{
-       struct cgroup_subsys_state *css;
-       u32 classid = 0;
-
-       if (in_interrupt())
-               return 0;
-
-       rcu_read_lock();
-       css = task_css(p, net_cls_subsys_id);
-       if (css)
-               classid = container_of(css,
-                                      struct cgroup_cls_state, css)->classid;
-       rcu_read_unlock();
 
-       return classid;
-}
-#endif
-#else /* !CGROUP_NET_CLS_CGROUP */
 static inline void sock_update_classid(struct sock *sk)
 {
-}
+       u32 classid;
 
-static inline u32 task_cls_classid(struct task_struct *p)
+       classid = task_cls_classid(current);
+       if (classid != sk->sk_classid)
+               sk->sk_classid = classid;
+}
+#else /* !CONFIG_CGROUP_NET_CLASSID */
+static inline void sock_update_classid(struct sock *sk)
 {
-       return 0;
 }
-#endif /* CGROUP_NET_CLS_CGROUP */
+#endif /* CONFIG_CGROUP_NET_CLASSID */
 #endif  /* _NET_CLS_CGROUP_H */

diff --git a/net/Kconfig b/net/Kconfig
index d334678c0bd8706d7c3efb6c0f35d0d62102c360..7da10b830d70a721228609050eb34f583a2b8f02 100644 (file)
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -245,6 +245,13 @@ config NETPRIO_CGROUP
          Cgroup subsystem for use in assigning processes to network priorities on
          a per-interface basis
 
+config CGROUP_NET_CLASSID
+       boolean "Network classid cgroup"
+       depends on CGROUPS
+       ---help---
+         Cgroup subsystem for use as general purpose socket classid marker that is
+         being used in cls_cgroup and for netfilter matching.
+
 config NET_RX_BUSY_POLL
        boolean
        default y

diff --git a/net/core/Makefile b/net/core/Makefile
index b33b996f5dd695f1c51498fedd7a1fe5aa368607..4839a27969643671ef6184407eda86d083fac128 100644 (file)
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_TRACEPOINTS) += net-traces.o
 obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o
 obj-$(CONFIG_NETWORK_PHY_TIMESTAMPING) += timestamping.o
 obj-$(CONFIG_NETPRIO_CGROUP) += netprio_cgroup.o
+obj-$(CONFIG_CGROUP_NET_CLASSID) += netclassid_cgroup.o

diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
new file mode 100644 (file)
index 0000000..719efd5
--- /dev/null
+++ b/net/core/netclassid_cgroup.c
@@ -0,0 +1,120 @@
+/*
+ * net/core/netclassid_cgroup.c        Classid Cgroupfs Handling
+ *
+ *             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.
+ *
+ * Authors:    Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/cgroup.h>
+#include <linux/fdtable.h>
+#include <net/cls_cgroup.h>
+#include <net/sock.h>
+
+static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
+{
+       return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
+}
+
+struct cgroup_cls_state *task_cls_state(struct task_struct *p)
+{
+       return css_cls_state(task_css(p, net_cls_subsys_id));
+}
+EXPORT_SYMBOL_GPL(task_cls_state);
+
+static struct cgroup_subsys_state *
+cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
+{
+       struct cgroup_cls_state *cs;
+
+       cs = kzalloc(sizeof(*cs), GFP_KERNEL);
+       if (!cs)
+               return ERR_PTR(-ENOMEM);
+
+       return &cs->css;
+}
+
+static int cgrp_css_online(struct cgroup_subsys_state *css)
+{
+       struct cgroup_cls_state *cs = css_cls_state(css);
+       struct cgroup_cls_state *parent = css_cls_state(css_parent(css));
+
+       if (parent)
+               cs->classid = parent->classid;
+
+       return 0;
+}
+
+static void cgrp_css_free(struct cgroup_subsys_state *css)
+{
+       kfree(css_cls_state(css));
+}
+
+static int update_classid(const void *v, struct file *file, unsigned n)
+{
+       int err;
+       struct socket *sock = sock_from_file(file, &err);
+
+       if (sock)
+               sock->sk->sk_classid = (u32)(unsigned long)v;
+
+       return 0;
+}
+
+static void cgrp_attach(struct cgroup_subsys_state *css,
+                       struct cgroup_taskset *tset)
+{
+       struct cgroup_cls_state *cs = css_cls_state(css);
+       void *v = (void *)(unsigned long)cs->classid;
+       struct task_struct *p;
+
+       cgroup_taskset_for_each(p, css, tset) {
+               task_lock(p);
+               iterate_fd(p->files, 0, update_classid, v);
+               task_unlock(p);
+       }
+}
+
+static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
+{
+       return css_cls_state(css)->classid;
+}
+
+static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
+                        u64 value)
+{
+       css_cls_state(css)->classid = (u32) value;
+
+       return 0;
+}
+
+static struct cftype ss_files[] = {
+       {
+               .name           = "classid",
+               .read_u64       = read_classid,
+               .write_u64      = write_classid,
+       },
+       { }     /* terminate */
+};
+
+struct cgroup_subsys net_cls_subsys = {
+       .name                   = "net_cls",
+       .css_alloc              = cgrp_css_alloc,
+       .css_online             = cgrp_css_online,
+       .css_free               = cgrp_css_free,
+       .attach                 = cgrp_attach,
+       .subsys_id              = net_cls_subsys_id,
+       .base_cftypes           = ss_files,
+       .module                 = THIS_MODULE,
+};
+
+static int __init init_netclassid_cgroup(void)
+{
+       return cgroup_load_subsys(&net_cls_subsys);
+}
+__initcall(init_netclassid_cgroup);

diff --git a/net/core/sock.c b/net/core/sock.c
index ab20ed9b0f31da64cb118cf645fa88f5787b5571..3f150729fb15a769bac3d37ae050bb6a3a5428b8 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1308,18 +1308,6 @@ static void sk_prot_free(struct proto *prot, struct sock *sk)
        module_put(owner);
 }
 
-#if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
-void sock_update_classid(struct sock *sk)
-{
-       u32 classid;
-
-       classid = task_cls_classid(current);
-       if (classid != sk->sk_classid)
-               sk->sk_classid = classid;
-}
-EXPORT_SYMBOL(sock_update_classid);
-#endif
-
 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
 void sock_update_netprioidx(struct sock *sk)
 {

diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index ad1f1d819203698cc5cb483cfc7edbfd15131b9a..f711a471d0b726748bc8b9a723a6045502b767c1 100644 (file)
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -435,6 +435,7 @@ config NET_CLS_FLOW
 config NET_CLS_CGROUP
        tristate "Control Group Classifier"
        select NET_CLS
+       select CGROUP_NET_CLASSID
        depends on CGROUPS
        ---help---
          Say Y here if you want to classify packets based on the control

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 16006c92c3fde515d9047a4e32f0ec3f0df2f005..838fa40abad15a8feb7add02f9b8aeeb7ad0086d 100644 (file)
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -11,109 +11,13 @@
 
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/types.h>
-#include <linux/string.h>
-#include <linux/errno.h>
 #include <linux/skbuff.h>
-#include <linux/cgroup.h>
 #include <linux/rcupdate.h>
-#include <linux/fdtable.h>
 #include <net/rtnetlink.h>
 #include <net/pkt_cls.h>
 #include <net/sock.h>
 #include <net/cls_cgroup.h>
 
-static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state *css)
-{
-       return css ? container_of(css, struct cgroup_cls_state, css) : NULL;
-}
-
-static inline struct cgroup_cls_state *task_cls_state(struct task_struct *p)
-{
-       return css_cls_state(task_css(p, net_cls_subsys_id));
-}
-
-static struct cgroup_subsys_state *
-cgrp_css_alloc(struct cgroup_subsys_state *parent_css)
-{
-       struct cgroup_cls_state *cs;
-
-       cs = kzalloc(sizeof(*cs), GFP_KERNEL);
-       if (!cs)
-               return ERR_PTR(-ENOMEM);
-       return &cs->css;
-}
-
-static int cgrp_css_online(struct cgroup_subsys_state *css)
-{
-       struct cgroup_cls_state *cs = css_cls_state(css);
-       struct cgroup_cls_state *parent = css_cls_state(css_parent(css));
-
-       if (parent)
-               cs->classid = parent->classid;
-       return 0;
-}
-
-static void cgrp_css_free(struct cgroup_subsys_state *css)
-{
-       kfree(css_cls_state(css));
-}
-
-static int update_classid(const void *v, struct file *file, unsigned n)
-{
-       int err;
-       struct socket *sock = sock_from_file(file, &err);
-       if (sock)
-               sock->sk->sk_classid = (u32)(unsigned long)v;
-       return 0;
-}
-
-static void cgrp_attach(struct cgroup_subsys_state *css,
-                       struct cgroup_taskset *tset)
-{
-       struct task_struct *p;
-       struct cgroup_cls_state *cs = css_cls_state(css);
-       void *v = (void *)(unsigned long)cs->classid;
-
-       cgroup_taskset_for_each(p, css, tset) {
-               task_lock(p);
-               iterate_fd(p->files, 0, update_classid, v);
-               task_unlock(p);
-       }
-}
-
-static u64 read_classid(struct cgroup_subsys_state *css, struct cftype *cft)
-{
-       return css_cls_state(css)->classid;
-}
-
-static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
-                        u64 value)
-{
-       css_cls_state(css)->classid = (u32) value;
-       return 0;
-}
-
-static struct cftype ss_files[] = {
-       {
-               .name = "classid",
-               .read_u64 = read_classid,
-               .write_u64 = write_classid,
-       },
-       { }     /* terminate */
-};
-
-struct cgroup_subsys net_cls_subsys = {
-       .name           = "net_cls",
-       .css_alloc      = cgrp_css_alloc,
-       .css_online     = cgrp_css_online,
-       .css_free       = cgrp_css_free,
-       .attach         = cgrp_attach,
-       .subsys_id      = net_cls_subsys_id,
-       .base_cftypes   = ss_files,
-       .module         = THIS_MODULE,
-};
-
 struct cls_cgroup_head {
        u32                     handle;
        struct tcf_exts         exts;
@@ -309,25 +213,12 @@ static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
 
 static int __init init_cgroup_cls(void)
 {
-       int ret;
-
-       ret = cgroup_load_subsys(&net_cls_subsys);
-       if (ret)
-               goto out;
-
-       ret = register_tcf_proto_ops(&cls_cgroup_ops);
-       if (ret)
-               cgroup_unload_subsys(&net_cls_subsys);
-
-out:
-       return ret;
+       return register_tcf_proto_ops(&cls_cgroup_ops);
 }
 
 static void __exit exit_cgroup_cls(void)
 {
        unregister_tcf_proto_ops(&cls_cgroup_ops);
-
-       cgroup_unload_subsys(&net_cls_subsys);
 }
 
 module_init(init_cgroup_cls);