--- /dev/null
+/*
+ * net/core/netprio_cgroup.c Priority Control Group
+ *
+ * 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: Neil Horman <nhorman@tuxdriver.com>
+ */
+
+#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/atomic.h>
+#include <net/rtnetlink.h>
+#include <net/pkt_cls.h>
+#include <net/sock.h>
+#include <net/netprio_cgroup.h>
+
+static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
+ struct cgroup *cgrp);
+static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp);
+static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp);
+
+struct cgroup_subsys net_prio_subsys = {
+ .name = "net_prio",
+ .create = cgrp_create,
+ .destroy = cgrp_destroy,
+ .populate = cgrp_populate,
+#ifdef CONFIG_NETPRIO_CGROUP
+ .subsys_id = net_prio_subsys_id,
+#endif
+ .module = THIS_MODULE
+};
+
+#define PRIOIDX_SZ 128
+
+static unsigned long prioidx_map[PRIOIDX_SZ];
+static DEFINE_SPINLOCK(prioidx_map_lock);
+static atomic_t max_prioidx = ATOMIC_INIT(0);
+
+static inline struct cgroup_netprio_state *cgrp_netprio_state(struct cgroup *cgrp)
+{
+ return container_of(cgroup_subsys_state(cgrp, net_prio_subsys_id),
+ struct cgroup_netprio_state, css);
+}
+
+static int get_prioidx(u32 *prio)
+{
+ unsigned long flags;
+ u32 prioidx;
+
+ spin_lock_irqsave(&prioidx_map_lock, flags);
+ prioidx = find_first_zero_bit(prioidx_map, sizeof(unsigned long) * PRIOIDX_SZ);
+ set_bit(prioidx, prioidx_map);
+ spin_unlock_irqrestore(&prioidx_map_lock, flags);
+ if (prioidx == sizeof(unsigned long) * PRIOIDX_SZ)
+ return -ENOSPC;
+
+ atomic_set(&max_prioidx, prioidx);
+ *prio = prioidx;
+ return 0;
+}
+
+static void put_prioidx(u32 idx)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&prioidx_map_lock, flags);
+ clear_bit(idx, prioidx_map);
+ spin_unlock_irqrestore(&prioidx_map_lock, flags);
+}
+
+static void extend_netdev_table(struct net_device *dev, u32 new_len)
+{
+ size_t new_size = sizeof(struct netprio_map) +
+ ((sizeof(u32) * new_len));
+ struct netprio_map *new_priomap = kzalloc(new_size, GFP_KERNEL);
+ struct netprio_map *old_priomap;
+ int i;
+
+ old_priomap = rtnl_dereference(dev->priomap);
+
+ if (!new_priomap) {
+ printk(KERN_WARNING "Unable to alloc new priomap!\n");
+ return;
+ }
+
+ for (i = 0;
+ old_priomap && (i < old_priomap->priomap_len);
+ i++)
+ new_priomap->priomap[i] = old_priomap->priomap[i];
+
+ new_priomap->priomap_len = new_len;
+
+ rcu_assign_pointer(dev->priomap, new_priomap);
+ if (old_priomap)
+ kfree_rcu(old_priomap, rcu);
+}
+
+static void update_netdev_tables(void)
+{
+ struct net_device *dev;
+ u32 max_len = atomic_read(&max_prioidx);
+ struct netprio_map *map;
+
+ rtnl_lock();
+ for_each_netdev(&init_net, dev) {
+ map = rtnl_dereference(dev->priomap);
+ if ((!map) ||
+ (map->priomap_len < max_len))
+ extend_netdev_table(dev, max_len);
+ }
+ rtnl_unlock();
+}
+
+static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
+ struct cgroup *cgrp)
+{
+ struct cgroup_netprio_state *cs;
+ int ret;
+
+ cs = kzalloc(sizeof(*cs), GFP_KERNEL);
+ if (!cs)
+ return ERR_PTR(-ENOMEM);
+
+ if (cgrp->parent && cgrp_netprio_state(cgrp->parent)->prioidx) {
+ kfree(cs);
+ return ERR_PTR(-EINVAL);
+ }
+
+ ret = get_prioidx(&cs->prioidx);
+ if (ret != 0) {
+ printk(KERN_WARNING "No space in priority index array\n");
+ kfree(cs);
+ return ERR_PTR(ret);
+ }
+
+ return &cs->css;
+}
+
+static void cgrp_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ struct cgroup_netprio_state *cs;
+ struct net_device *dev;
+ struct netprio_map *map;
+
+ cs = cgrp_netprio_state(cgrp);
+ rtnl_lock();
+ for_each_netdev(&init_net, dev) {
+ map = rtnl_dereference(dev->priomap);
+ if (map)
+ map->priomap[cs->prioidx] = 0;
+ }
+ rtnl_unlock();
+ put_prioidx(cs->prioidx);
+ kfree(cs);
+}
+
+static u64 read_prioidx(struct cgroup *cgrp, struct cftype *cft)
+{
+ return (u64)cgrp_netprio_state(cgrp)->prioidx;
+}
+
+static int read_priomap(struct cgroup *cont, struct cftype *cft,
+ struct cgroup_map_cb *cb)
+{
+ struct net_device *dev;
+ u32 prioidx = cgrp_netprio_state(cont)->prioidx;
+ u32 priority;
+ struct netprio_map *map;
+
+ rcu_read_lock();
+ for_each_netdev_rcu(&init_net, dev) {
+ map = rcu_dereference(dev->priomap);
+ priority = map ? map->priomap[prioidx] : 0;
+ cb->fill(cb, dev->name, priority);
+ }
+ rcu_read_unlock();
+ return 0;
+}
+
+static int write_priomap(struct cgroup *cgrp, struct cftype *cft,
+ const char *buffer)
+{
+ char *devname = kstrdup(buffer, GFP_KERNEL);
+ int ret = -EINVAL;
+ u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
+ unsigned long priority;
+ char *priostr;
+ struct net_device *dev;
+ struct netprio_map *map;
+
+ if (!devname)
+ return -ENOMEM;
+
+ /*
+ * Minimally sized valid priomap string
+ */
+ if (strlen(devname) < 3)
+ goto out_free_devname;
+
+ priostr = strstr(devname, " ");
+ if (!priostr)
+ goto out_free_devname;
+
+ /*
+ *Separate the devname from the associated priority
+ *and advance the priostr poitner to the priority value
+ */
+ *priostr = '\0';
+ priostr++;
+
+ /*
+ * If the priostr points to NULL, we're at the end of the passed
+ * in string, and its not a valid write
+ */
+ if (*priostr == '\0')
+ goto out_free_devname;
+
+ ret = kstrtoul(priostr, 10, &priority);
+ if (ret < 0)
+ goto out_free_devname;
+
+ ret = -ENODEV;
+
+ dev = dev_get_by_name(&init_net, devname);
+ if (!dev)
+ goto out_free_devname;
+
+ update_netdev_tables();
+ ret = 0;
+ rcu_read_lock();
+ map = rcu_dereference(dev->priomap);
+ if (map)
+ map->priomap[prioidx] = priority;
+ rcu_read_unlock();
+ dev_put(dev);
+
+out_free_devname:
+ kfree(devname);
+ return ret;
+}
+
+static struct cftype ss_files[] = {
+ {
+ .name = "prioidx",
+ .read_u64 = read_prioidx,
+ },
+ {
+ .name = "ifpriomap",
+ .read_map = read_priomap,
+ .write_string = write_priomap,
+ },
+};
+
+static int cgrp_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
+{
+ return cgroup_add_files(cgrp, ss, ss_files, ARRAY_SIZE(ss_files));
+}
+
+static int netprio_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = ptr;
+ struct netprio_map *old;
+ u32 max_len = atomic_read(&max_prioidx);
+
+ /*
+ * Note this is called with rtnl_lock held so we have update side
+ * protection on our rcu assignments
+ */
+
+ switch (event) {
+
+ case NETDEV_REGISTER:
+ if (max_len)
+ extend_netdev_table(dev, max_len);
+ break;
+ case NETDEV_UNREGISTER:
+ old = rtnl_dereference(dev->priomap);
+ rcu_assign_pointer(dev->priomap, NULL);
+ if (old)
+ kfree_rcu(old, rcu);
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block netprio_device_notifier = {
+ .notifier_call = netprio_device_event
+};
+
+static int __init init_cgroup_netprio(void)
+{
+ int ret;
+
+ ret = cgroup_load_subsys(&net_prio_subsys);
+ if (ret)
+ goto out;
+#ifndef CONFIG_NETPRIO_CGROUP
+ smp_wmb();
+ net_prio_subsys_id = net_prio_subsys.subsys_id;
+#endif
+
+ register_netdevice_notifier(&netprio_device_notifier);
+
+out:
+ return ret;
+}
+
+static void __exit exit_cgroup_netprio(void)
+{
+ struct netprio_map *old;
+ struct net_device *dev;
+
+ unregister_netdevice_notifier(&netprio_device_notifier);
+
+ cgroup_unload_subsys(&net_prio_subsys);
+
+#ifndef CONFIG_NETPRIO_CGROUP
+ net_prio_subsys_id = -1;
+ synchronize_rcu();
+#endif
+
+ rtnl_lock();
+ for_each_netdev(&init_net, dev) {
+ old = rtnl_dereference(dev->priomap);
+ rcu_assign_pointer(dev->priomap, NULL);
+ if (old)
+ kfree_rcu(old, rcu);
+ }
+ rtnl_unlock();
+}
+
+module_init(init_cgroup_netprio);
+module_exit(exit_cgroup_netprio);
+MODULE_LICENSE("GPL v2");
projects / cascardo / linux.git / commitdiff