v4.19.13 snapshot.
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
new file mode 100644
index 0000000..8bf66d0
--- /dev/null
+++ b/net/sched/act_mirred.c
@@ -0,0 +1,454 @@
+/*
+ * net/sched/act_mirred.c packet mirroring and redirect actions
+ *
+ * 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: Jamal Hadi Salim (2002-4)
+ *
+ * TODO: Add ingress support (and socket redirect support)
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gfp.h>
+#include <linux/if_arp.h>
+#include <net/net_namespace.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <linux/tc_act/tc_mirred.h>
+#include <net/tc_act/tc_mirred.h>
+
+static LIST_HEAD(mirred_list);
+static DEFINE_SPINLOCK(mirred_list_lock);
+
+static bool tcf_mirred_is_act_redirect(int action)
+{
+ return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR;
+}
+
+static bool tcf_mirred_act_wants_ingress(int action)
+{
+ switch (action) {
+ case TCA_EGRESS_REDIR:
+ case TCA_EGRESS_MIRROR:
+ return false;
+ case TCA_INGRESS_REDIR:
+ case TCA_INGRESS_MIRROR:
+ return true;
+ default:
+ BUG();
+ }
+}
+
+static bool tcf_mirred_can_reinsert(int action)
+{
+ switch (action) {
+ case TC_ACT_SHOT:
+ case TC_ACT_STOLEN:
+ case TC_ACT_QUEUED:
+ case TC_ACT_TRAP:
+ return true;
+ }
+ return false;
+}
+
+static struct net_device *tcf_mirred_dev_dereference(struct tcf_mirred *m)
+{
+ return rcu_dereference_protected(m->tcfm_dev,
+ lockdep_is_held(&m->tcf_lock));
+}
+
+static void tcf_mirred_release(struct tc_action *a)
+{
+ struct tcf_mirred *m = to_mirred(a);
+ struct net_device *dev;
+
+ spin_lock(&mirred_list_lock);
+ list_del(&m->tcfm_list);
+ spin_unlock(&mirred_list_lock);
+
+ /* last reference to action, no need to lock */
+ dev = rcu_dereference_protected(m->tcfm_dev, 1);
+ if (dev)
+ dev_put(dev);
+}
+
+static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
+ [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
+};
+
+static unsigned int mirred_net_id;
+static struct tc_action_ops act_mirred_ops;
+
+static int tcf_mirred_init(struct net *net, struct nlattr *nla,
+ struct nlattr *est, struct tc_action **a,
+ int ovr, int bind, bool rtnl_held,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, mirred_net_id);
+ struct nlattr *tb[TCA_MIRRED_MAX + 1];
+ bool mac_header_xmit = false;
+ struct tc_mirred *parm;
+ struct tcf_mirred *m;
+ struct net_device *dev;
+ bool exists = false;
+ int ret, err;
+
+ if (!nla) {
+ NL_SET_ERR_MSG_MOD(extack, "Mirred requires attributes to be passed");
+ return -EINVAL;
+ }
+ ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy, extack);
+ if (ret < 0)
+ return ret;
+ if (!tb[TCA_MIRRED_PARMS]) {
+ NL_SET_ERR_MSG_MOD(extack, "Missing required mirred parameters");
+ return -EINVAL;
+ }
+ parm = nla_data(tb[TCA_MIRRED_PARMS]);
+
+ err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
+ if (err < 0)
+ return err;
+ exists = err;
+ if (exists && bind)
+ return 0;
+
+ switch (parm->eaction) {
+ case TCA_EGRESS_MIRROR:
+ case TCA_EGRESS_REDIR:
+ case TCA_INGRESS_REDIR:
+ case TCA_INGRESS_MIRROR:
+ break;
+ default:
+ if (exists)
+ tcf_idr_release(*a, bind);
+ else
+ tcf_idr_cleanup(tn, parm->index);
+ NL_SET_ERR_MSG_MOD(extack, "Unknown mirred option");
+ return -EINVAL;
+ }
+
+ if (!exists) {
+ if (!parm->ifindex) {
+ tcf_idr_cleanup(tn, parm->index);
+ NL_SET_ERR_MSG_MOD(extack, "Specified device does not exist");
+ return -EINVAL;
+ }
+ ret = tcf_idr_create(tn, parm->index, est, a,
+ &act_mirred_ops, bind, true);
+ if (ret) {
+ tcf_idr_cleanup(tn, parm->index);
+ return ret;
+ }
+ ret = ACT_P_CREATED;
+ } else if (!ovr) {
+ tcf_idr_release(*a, bind);
+ return -EEXIST;
+ }
+ m = to_mirred(*a);
+
+ spin_lock_bh(&m->tcf_lock);
+ m->tcf_action = parm->action;
+ m->tcfm_eaction = parm->eaction;
+
+ if (parm->ifindex) {
+ dev = dev_get_by_index(net, parm->ifindex);
+ if (!dev) {
+ spin_unlock_bh(&m->tcf_lock);
+ tcf_idr_release(*a, bind);
+ return -ENODEV;
+ }
+ mac_header_xmit = dev_is_mac_header_xmit(dev);
+ rcu_swap_protected(m->tcfm_dev, dev,
+ lockdep_is_held(&m->tcf_lock));
+ if (dev)
+ dev_put(dev);
+ m->tcfm_mac_header_xmit = mac_header_xmit;
+ }
+ spin_unlock_bh(&m->tcf_lock);
+
+ if (ret == ACT_P_CREATED) {
+ spin_lock(&mirred_list_lock);
+ list_add(&m->tcfm_list, &mirred_list);
+ spin_unlock(&mirred_list_lock);
+
+ tcf_idr_insert(tn, *a);
+ }
+
+ return ret;
+}
+
+static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a,
+ struct tcf_result *res)
+{
+ struct tcf_mirred *m = to_mirred(a);
+ struct sk_buff *skb2 = skb;
+ bool m_mac_header_xmit;
+ struct net_device *dev;
+ int retval, err = 0;
+ bool use_reinsert;
+ bool want_ingress;
+ bool is_redirect;
+ int m_eaction;
+ int mac_len;
+
+ tcf_lastuse_update(&m->tcf_tm);
+ bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
+
+ m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit);
+ m_eaction = READ_ONCE(m->tcfm_eaction);
+ retval = READ_ONCE(m->tcf_action);
+ dev = rcu_dereference_bh(m->tcfm_dev);
+ if (unlikely(!dev)) {
+ pr_notice_once("tc mirred: target device is gone\n");
+ goto out;
+ }
+
+ if (unlikely(!(dev->flags & IFF_UP))) {
+ net_notice_ratelimited("tc mirred to Houston: device %s is down\n",
+ dev->name);
+ goto out;
+ }
+
+ /* we could easily avoid the clone only if called by ingress and clsact;
+ * since we can't easily detect the clsact caller, skip clone only for
+ * ingress - that covers the TC S/W datapath.
+ */
+ is_redirect = tcf_mirred_is_act_redirect(m_eaction);
+ use_reinsert = skb_at_tc_ingress(skb) && is_redirect &&
+ tcf_mirred_can_reinsert(retval);
+ if (!use_reinsert) {
+ skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (!skb2)
+ goto out;
+ }
+
+ /* If action's target direction differs than filter's direction,
+ * and devices expect a mac header on xmit, then mac push/pull is
+ * needed.
+ */
+ want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
+ if (skb_at_tc_ingress(skb) != want_ingress && m_mac_header_xmit) {
+ if (!skb_at_tc_ingress(skb)) {
+ /* caught at egress, act ingress: pull mac */
+ mac_len = skb_network_header(skb) - skb_mac_header(skb);
+ skb_pull_rcsum(skb2, mac_len);
+ } else {
+ /* caught at ingress, act egress: push mac */
+ skb_push_rcsum(skb2, skb->mac_len);
+ }
+ }
+
+ skb2->skb_iif = skb->dev->ifindex;
+ skb2->dev = dev;
+
+ /* mirror is always swallowed */
+ if (is_redirect) {
+ skb2->tc_redirected = 1;
+ skb2->tc_from_ingress = skb2->tc_at_ingress;
+
+ /* let's the caller reinsert the packet, if possible */
+ if (use_reinsert) {
+ res->ingress = want_ingress;
+ res->qstats = this_cpu_ptr(m->common.cpu_qstats);
+ return TC_ACT_REINSERT;
+ }
+ }
+
+ if (!want_ingress)
+ err = dev_queue_xmit(skb2);
+ else
+ err = netif_receive_skb(skb2);
+
+ if (err) {
+out:
+ qstats_overlimit_inc(this_cpu_ptr(m->common.cpu_qstats));
+ if (tcf_mirred_is_act_redirect(m_eaction))
+ retval = TC_ACT_SHOT;
+ }
+
+ return retval;
+}
+
+static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
+ u64 lastuse)
+{
+ struct tcf_mirred *m = to_mirred(a);
+ struct tcf_t *tm = &m->tcf_tm;
+
+ _bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
+ tm->lastuse = max_t(u64, tm->lastuse, lastuse);
+}
+
+static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
+ int ref)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tcf_mirred *m = to_mirred(a);
+ struct tc_mirred opt = {
+ .index = m->tcf_index,
+ .refcnt = refcount_read(&m->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
+ };
+ struct net_device *dev;
+ struct tcf_t t;
+
+ spin_lock_bh(&m->tcf_lock);
+ opt.action = m->tcf_action;
+ opt.eaction = m->tcfm_eaction;
+ dev = tcf_mirred_dev_dereference(m);
+ if (dev)
+ opt.ifindex = dev->ifindex;
+
+ if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
+ goto nla_put_failure;
+
+ tcf_tm_dump(&t, &m->tcf_tm);
+ if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
+ goto nla_put_failure;
+ spin_unlock_bh(&m->tcf_lock);
+
+ return skb->len;
+
+nla_put_failure:
+ spin_unlock_bh(&m->tcf_lock);
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int tcf_mirred_walker(struct net *net, struct sk_buff *skb,
+ struct netlink_callback *cb, int type,
+ const struct tc_action_ops *ops,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, mirred_net_id);
+
+ return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_mirred_search(struct net *net, struct tc_action **a, u32 index,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, mirred_net_id);
+
+ return tcf_idr_search(tn, a, index);
+}
+
+static int mirred_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct tcf_mirred *m;
+
+ ASSERT_RTNL();
+ if (event == NETDEV_UNREGISTER) {
+ spin_lock(&mirred_list_lock);
+ list_for_each_entry(m, &mirred_list, tcfm_list) {
+ spin_lock_bh(&m->tcf_lock);
+ if (tcf_mirred_dev_dereference(m) == dev) {
+ dev_put(dev);
+ /* Note : no rcu grace period necessary, as
+ * net_device are already rcu protected.
+ */
+ RCU_INIT_POINTER(m->tcfm_dev, NULL);
+ }
+ spin_unlock_bh(&m->tcf_lock);
+ }
+ spin_unlock(&mirred_list_lock);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block mirred_device_notifier = {
+ .notifier_call = mirred_device_event,
+};
+
+static struct net_device *tcf_mirred_get_dev(const struct tc_action *a)
+{
+ struct tcf_mirred *m = to_mirred(a);
+ struct net_device *dev;
+
+ rcu_read_lock();
+ dev = rcu_dereference(m->tcfm_dev);
+ if (dev)
+ dev_hold(dev);
+ rcu_read_unlock();
+
+ return dev;
+}
+
+static void tcf_mirred_put_dev(struct net_device *dev)
+{
+ dev_put(dev);
+}
+
+static struct tc_action_ops act_mirred_ops = {
+ .kind = "mirred",
+ .type = TCA_ACT_MIRRED,
+ .owner = THIS_MODULE,
+ .act = tcf_mirred_act,
+ .stats_update = tcf_stats_update,
+ .dump = tcf_mirred_dump,
+ .cleanup = tcf_mirred_release,
+ .init = tcf_mirred_init,
+ .walk = tcf_mirred_walker,
+ .lookup = tcf_mirred_search,
+ .size = sizeof(struct tcf_mirred),
+ .get_dev = tcf_mirred_get_dev,
+ .put_dev = tcf_mirred_put_dev,
+};
+
+static __net_init int mirred_init_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, mirred_net_id);
+
+ return tc_action_net_init(tn, &act_mirred_ops);
+}
+
+static void __net_exit mirred_exit_net(struct list_head *net_list)
+{
+ tc_action_net_exit(net_list, mirred_net_id);
+}
+
+static struct pernet_operations mirred_net_ops = {
+ .init = mirred_init_net,
+ .exit_batch = mirred_exit_net,
+ .id = &mirred_net_id,
+ .size = sizeof(struct tc_action_net),
+};
+
+MODULE_AUTHOR("Jamal Hadi Salim(2002)");
+MODULE_DESCRIPTION("Device Mirror/redirect actions");
+MODULE_LICENSE("GPL");
+
+static int __init mirred_init_module(void)
+{
+ int err = register_netdevice_notifier(&mirred_device_notifier);
+ if (err)
+ return err;
+
+ pr_info("Mirror/redirect action on\n");
+ return tcf_register_action(&act_mirred_ops, &mirred_net_ops);
+}
+
+static void __exit mirred_cleanup_module(void)
+{
+ tcf_unregister_action(&act_mirred_ops, &mirred_net_ops);
+ unregister_netdevice_notifier(&mirred_device_notifier);
+}
+
+module_init(mirred_init_module);
+module_exit(mirred_cleanup_module);