File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
new file mode 100644
index 0000000..f23a3b6
--- /dev/null
+++ b/net/sched/cls_fw.c
@@ -0,0 +1,438 @@
+/*
+ * net/sched/cls_fw.c	Classifier mapping ipchains' fwmark to traffic class.
+ *
+ *		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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ * Changes:
+ * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_walk off by one
+ * Karlis Peisenieks <karlis@mt.lv> : 990415 : fw_delete killed all the filter (and kernel).
+ * Alex <alex@pilotsoft.com> : 2004xxyy: Added Action extension
+ *
+ * JHS: We should remove the CONFIG_NET_CLS_IND from here
+ * eventually when the meta match extension is made available
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/act_api.h>
+#include <net/pkt_cls.h>
+
+#define HTSIZE 256
+
+struct fw_head {
+	u32			mask;
+	struct fw_filter __rcu	*ht[HTSIZE];
+	struct rcu_head		rcu;
+};
+
+struct fw_filter {
+	struct fw_filter __rcu	*next;
+	u32			id;
+	struct tcf_result	res;
+#ifdef CONFIG_NET_CLS_IND
+	int			ifindex;
+#endif /* CONFIG_NET_CLS_IND */
+	struct tcf_exts		exts;
+	struct tcf_proto	*tp;
+	struct rcu_head		rcu;
+};
+
+static u32 fw_hash(u32 handle)
+{
+	handle ^= (handle >> 16);
+	handle ^= (handle >> 8);
+	return handle % HTSIZE;
+}
+
+static int fw_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+			  struct tcf_result *res)
+{
+	struct fw_head *head = rcu_dereference_bh(tp->root);
+	struct fw_filter *f;
+	int r;
+	u32 id = skb->mark;
+
+	if (head != NULL) {
+		id &= head->mask;
+
+		for (f = rcu_dereference_bh(head->ht[fw_hash(id)]); f;
+		     f = rcu_dereference_bh(f->next)) {
+			if (f->id == id) {
+				*res = f->res;
+#ifdef CONFIG_NET_CLS_IND
+				if (!tcf_match_indev(skb, f->ifindex))
+					continue;
+#endif /* CONFIG_NET_CLS_IND */
+				r = tcf_exts_exec(skb, &f->exts, res);
+				if (r < 0)
+					continue;
+
+				return r;
+			}
+		}
+	} else {
+		/* Old method: classify the packet using its skb mark. */
+		if (id && (TC_H_MAJ(id) == 0 ||
+			   !(TC_H_MAJ(id ^ tp->q->handle)))) {
+			res->classid = id;
+			res->class = 0;
+			return 0;
+		}
+	}
+
+	return -1;
+}
+
+static unsigned long fw_get(struct tcf_proto *tp, u32 handle)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct fw_filter *f;
+
+	if (head == NULL)
+		return 0;
+
+	f = rtnl_dereference(head->ht[fw_hash(handle)]);
+	for (; f; f = rtnl_dereference(f->next)) {
+		if (f->id == handle)
+			return (unsigned long)f;
+	}
+	return 0;
+}
+
+static int fw_init(struct tcf_proto *tp)
+{
+	/* We don't allocate fw_head here, because in the old method
+	 * we don't need it at all.
+	 */
+	return 0;
+}
+
+static void fw_delete_filter(struct rcu_head *head)
+{
+	struct fw_filter *f = container_of(head, struct fw_filter, rcu);
+
+	tcf_exts_destroy(&f->exts);
+	kfree(f);
+}
+
+static bool fw_destroy(struct tcf_proto *tp, bool force)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct fw_filter *f;
+	int h;
+
+	if (head == NULL)
+		return true;
+
+	if (!force) {
+		for (h = 0; h < HTSIZE; h++)
+			if (rcu_access_pointer(head->ht[h]))
+				return false;
+	}
+
+	for (h = 0; h < HTSIZE; h++) {
+		while ((f = rtnl_dereference(head->ht[h])) != NULL) {
+			RCU_INIT_POINTER(head->ht[h],
+					 rtnl_dereference(f->next));
+			tcf_unbind_filter(tp, &f->res);
+			call_rcu(&f->rcu, fw_delete_filter);
+		}
+	}
+	RCU_INIT_POINTER(tp->root, NULL);
+	kfree_rcu(head, rcu);
+	return true;
+}
+
+static int fw_delete(struct tcf_proto *tp, unsigned long arg)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct fw_filter *f = (struct fw_filter *)arg;
+	struct fw_filter __rcu **fp;
+	struct fw_filter *pfp;
+
+	if (head == NULL || f == NULL)
+		goto out;
+
+	fp = &head->ht[fw_hash(f->id)];
+
+	for (pfp = rtnl_dereference(*fp); pfp;
+	     fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
+		if (pfp == f) {
+			RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
+			tcf_unbind_filter(tp, &f->res);
+			call_rcu(&f->rcu, fw_delete_filter);
+			return 0;
+		}
+	}
+out:
+	return -EINVAL;
+}
+
+static const struct nla_policy fw_policy[TCA_FW_MAX + 1] = {
+	[TCA_FW_CLASSID]	= { .type = NLA_U32 },
+	[TCA_FW_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
+	[TCA_FW_MASK]		= { .type = NLA_U32 },
+};
+
+static int
+fw_change_attrs(struct net *net, struct tcf_proto *tp, struct fw_filter *f,
+	struct nlattr **tb, struct nlattr **tca, unsigned long base, bool ovr)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct tcf_exts e;
+	u32 mask;
+	int err;
+
+	tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE);
+	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
+	if (err < 0)
+		return err;
+
+	if (tb[TCA_FW_CLASSID]) {
+		f->res.classid = nla_get_u32(tb[TCA_FW_CLASSID]);
+		tcf_bind_filter(tp, &f->res, base);
+	}
+
+#ifdef CONFIG_NET_CLS_IND
+	if (tb[TCA_FW_INDEV]) {
+		int ret;
+		ret = tcf_change_indev(net, tb[TCA_FW_INDEV]);
+		if (ret < 0) {
+			err = ret;
+			goto errout;
+		}
+		f->ifindex = ret;
+	}
+#endif /* CONFIG_NET_CLS_IND */
+
+	err = -EINVAL;
+	if (tb[TCA_FW_MASK]) {
+		mask = nla_get_u32(tb[TCA_FW_MASK]);
+		if (mask != head->mask)
+			goto errout;
+	} else if (head->mask != 0xFFFFFFFF)
+		goto errout;
+
+	tcf_exts_change(tp, &f->exts, &e);
+
+	return 0;
+errout:
+	tcf_exts_destroy(&e);
+	return err;
+}
+
+static int fw_change(struct net *net, struct sk_buff *in_skb,
+		     struct tcf_proto *tp, unsigned long base,
+		     u32 handle,
+		     struct nlattr **tca,
+		     unsigned long *arg, bool ovr)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct fw_filter *f = (struct fw_filter *) *arg;
+	struct nlattr *opt = tca[TCA_OPTIONS];
+	struct nlattr *tb[TCA_FW_MAX + 1];
+	int err;
+
+	if (!opt)
+		return handle ? -EINVAL : 0; /* Succeed if it is old method. */
+
+	err = nla_parse_nested(tb, TCA_FW_MAX, opt, fw_policy);
+	if (err < 0)
+		return err;
+
+	if (f) {
+		struct fw_filter *pfp, *fnew;
+		struct fw_filter __rcu **fp;
+
+		if (f->id != handle && handle)
+			return -EINVAL;
+
+		fnew = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
+		if (!fnew)
+			return -ENOBUFS;
+
+		fnew->id = f->id;
+		fnew->res = f->res;
+#ifdef CONFIG_NET_CLS_IND
+		fnew->ifindex = f->ifindex;
+#endif /* CONFIG_NET_CLS_IND */
+		fnew->tp = f->tp;
+
+		tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE);
+
+		err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr);
+		if (err < 0) {
+			kfree(fnew);
+			return err;
+		}
+
+		fp = &head->ht[fw_hash(fnew->id)];
+		for (pfp = rtnl_dereference(*fp); pfp;
+		     fp = &pfp->next, pfp = rtnl_dereference(*fp))
+			if (pfp == f)
+				break;
+
+		RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
+		rcu_assign_pointer(*fp, fnew);
+		tcf_unbind_filter(tp, &f->res);
+		call_rcu(&f->rcu, fw_delete_filter);
+
+		*arg = (unsigned long)fnew;
+		return err;
+	}
+
+	if (!handle)
+		return -EINVAL;
+
+	if (!head) {
+		u32 mask = 0xFFFFFFFF;
+		if (tb[TCA_FW_MASK])
+			mask = nla_get_u32(tb[TCA_FW_MASK]);
+
+		head = kzalloc(sizeof(*head), GFP_KERNEL);
+		if (!head)
+			return -ENOBUFS;
+		head->mask = mask;
+
+		rcu_assign_pointer(tp->root, head);
+	}
+
+	f = kzalloc(sizeof(struct fw_filter), GFP_KERNEL);
+	if (f == NULL)
+		return -ENOBUFS;
+
+	tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE);
+	f->id = handle;
+	f->tp = tp;
+
+	err = fw_change_attrs(net, tp, f, tb, tca, base, ovr);
+	if (err < 0)
+		goto errout;
+
+	RCU_INIT_POINTER(f->next, head->ht[fw_hash(handle)]);
+	rcu_assign_pointer(head->ht[fw_hash(handle)], f);
+
+	*arg = (unsigned long)f;
+	return 0;
+
+errout:
+	kfree(f);
+	return err;
+}
+
+static void fw_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	int h;
+
+	if (head == NULL)
+		arg->stop = 1;
+
+	if (arg->stop)
+		return;
+
+	for (h = 0; h < HTSIZE; h++) {
+		struct fw_filter *f;
+
+		for (f = rtnl_dereference(head->ht[h]); f;
+		     f = rtnl_dereference(f->next)) {
+			if (arg->count < arg->skip) {
+				arg->count++;
+				continue;
+			}
+			if (arg->fn(tp, (unsigned long)f, arg) < 0) {
+				arg->stop = 1;
+				return;
+			}
+			arg->count++;
+		}
+	}
+}
+
+static int fw_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
+		   struct sk_buff *skb, struct tcmsg *t)
+{
+	struct fw_head *head = rtnl_dereference(tp->root);
+	struct fw_filter *f = (struct fw_filter *)fh;
+	struct nlattr *nest;
+
+	if (f == NULL)
+		return skb->len;
+
+	t->tcm_handle = f->id;
+
+	if (!f->res.classid && !tcf_exts_is_available(&f->exts))
+		return skb->len;
+
+	nest = nla_nest_start(skb, TCA_OPTIONS);
+	if (nest == NULL)
+		goto nla_put_failure;
+
+	if (f->res.classid &&
+	    nla_put_u32(skb, TCA_FW_CLASSID, f->res.classid))
+		goto nla_put_failure;
+#ifdef CONFIG_NET_CLS_IND
+	if (f->ifindex) {
+		struct net_device *dev;
+		dev = __dev_get_by_index(net, f->ifindex);
+		if (dev && nla_put_string(skb, TCA_FW_INDEV, dev->name))
+			goto nla_put_failure;
+	}
+#endif /* CONFIG_NET_CLS_IND */
+	if (head->mask != 0xFFFFFFFF &&
+	    nla_put_u32(skb, TCA_FW_MASK, head->mask))
+		goto nla_put_failure;
+
+	if (tcf_exts_dump(skb, &f->exts) < 0)
+		goto nla_put_failure;
+
+	nla_nest_end(skb, nest);
+
+	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
+		goto nla_put_failure;
+
+	return skb->len;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -1;
+}
+
+static struct tcf_proto_ops cls_fw_ops __read_mostly = {
+	.kind		=	"fw",
+	.classify	=	fw_classify,
+	.init		=	fw_init,
+	.destroy	=	fw_destroy,
+	.get		=	fw_get,
+	.change		=	fw_change,
+	.delete		=	fw_delete,
+	.walk		=	fw_walk,
+	.dump		=	fw_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init init_fw(void)
+{
+	return register_tcf_proto_ops(&cls_fw_ops);
+}
+
+static void __exit exit_fw(void)
+{
+	unregister_tcf_proto_ops(&cls_fw_ops);
+}
+
+module_init(init_fw)
+module_exit(exit_fw)
+MODULE_LICENSE("GPL");