1 files changed, 634 insertions, 0 deletions

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
new file mode 100644
index 000000000..a75864d93
--- /dev/null
+++ b/net/sched/cls_api.c
@@ -0,0 +1,634 @@
+/*
+ * net/sched/cls_api.c	Packet classifier API.
+ *
+ *		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:
+ *
+ * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+#include <linux/kmod.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+/* The list of all installed classifier types */
+static LIST_HEAD(tcf_proto_base);
+
+/* Protects list of registered TC modules. It is pure SMP lock. */
+static DEFINE_RWLOCK(cls_mod_lock);
+
+/* Find classifier type by string name */
+
+static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
+{
+	const struct tcf_proto_ops *t, *res = NULL;
+
+	if (kind) {
+		read_lock(&cls_mod_lock);
+		list_for_each_entry(t, &tcf_proto_base, head) {
+			if (nla_strcmp(kind, t->kind) == 0) {
+				if (try_module_get(t->owner))
+					res = t;
+				break;
+			}
+		}
+		read_unlock(&cls_mod_lock);
+	}
+	return res;
+}
+
+/* Register(unregister) new classifier type */
+
+int register_tcf_proto_ops(struct tcf_proto_ops *ops)
+{
+	struct tcf_proto_ops *t;
+	int rc = -EEXIST;
+
+	write_lock(&cls_mod_lock);
+	list_for_each_entry(t, &tcf_proto_base, head)
+		if (!strcmp(ops->kind, t->kind))
+			goto out;
+
+	list_add_tail(&ops->head, &tcf_proto_base);
+	rc = 0;
+out:
+	write_unlock(&cls_mod_lock);
+	return rc;
+}
+EXPORT_SYMBOL(register_tcf_proto_ops);
+
+int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
+{
+	struct tcf_proto_ops *t;
+	int rc = -ENOENT;
+
+	/* Wait for outstanding call_rcu()s, if any, from a
+	 * tcf_proto_ops's destroy() handler.
+	 */
+	rcu_barrier();
+
+	write_lock(&cls_mod_lock);
+	list_for_each_entry(t, &tcf_proto_base, head) {
+		if (t == ops) {
+			list_del(&t->head);
+			rc = 0;
+			break;
+		}
+	}
+	write_unlock(&cls_mod_lock);
+	return rc;
+}
+EXPORT_SYMBOL(unregister_tcf_proto_ops);
+
+static int tfilter_notify(struct net *net, struct sk_buff *oskb,
+			  struct nlmsghdr *n, struct tcf_proto *tp,
+			  unsigned long fh, int event);
+
+
+/* Select new prio value from the range, managed by kernel. */
+
+static inline u32 tcf_auto_prio(struct tcf_proto *tp)
+{
+	u32 first = TC_H_MAKE(0xC0000000U, 0U);
+
+	if (tp)
+		first = tp->prio - 1;
+
+	return first;
+}
+
+/* Add/change/delete/get a filter node */
+
+static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
+{
+	struct net *net = sock_net(skb->sk);
+	struct nlattr *tca[TCA_MAX + 1];
+	struct tcmsg *t;
+	u32 protocol;
+	u32 prio;
+	u32 nprio;
+	u32 parent;
+	struct net_device *dev;
+	struct Qdisc  *q;
+	struct tcf_proto __rcu **back;
+	struct tcf_proto __rcu **chain;
+	struct tcf_proto *tp;
+	const struct tcf_proto_ops *tp_ops;
+	const struct Qdisc_class_ops *cops;
+	unsigned long cl;
+	unsigned long fh;
+	int err;
+	int tp_created = 0;
+
+	if ((n->nlmsg_type != RTM_GETTFILTER) &&
+	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+replay:
+	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
+	if (err < 0)
+		return err;
+
+	t = nlmsg_data(n);
+	protocol = TC_H_MIN(t->tcm_info);
+	prio = TC_H_MAJ(t->tcm_info);
+	nprio = prio;
+	parent = t->tcm_parent;
+	cl = 0;
+
+	if (prio == 0) {
+		/* If no priority is given, user wants we allocated it. */
+		if (n->nlmsg_type != RTM_NEWTFILTER ||
+		    !(n->nlmsg_flags & NLM_F_CREATE))
+			return -ENOENT;
+		prio = TC_H_MAKE(0x80000000U, 0U);
+	}
+
+	/* Find head of filter chain. */
+
+	/* Find link */
+	dev = __dev_get_by_index(net, t->tcm_ifindex);
+	if (dev == NULL)
+		return -ENODEV;
+
+	/* Find qdisc */
+	if (!parent) {
+		q = dev->qdisc;
+		parent = q->handle;
+	} else {
+		q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
+		if (q == NULL)
+			return -EINVAL;
+	}
+
+	/* Is it classful? */
+	cops = q->ops->cl_ops;
+	if (!cops)
+		return -EINVAL;
+
+	if (cops->tcf_chain == NULL)
+		return -EOPNOTSUPP;
+
+	/* Do we search for filter, attached to class? */
+	if (TC_H_MIN(parent)) {
+		cl = cops->get(q, parent);
+		if (cl == 0)
+			return -ENOENT;
+	}
+
+	/* And the last stroke */
+	chain = cops->tcf_chain(q, cl);
+	err = -EINVAL;
+	if (chain == NULL)
+		goto errout;
+
+	/* Check the chain for existence of proto-tcf with this priority */
+	for (back = chain;
+	     (tp = rtnl_dereference(*back)) != NULL;
+	     back = &tp->next) {
+		if (tp->prio >= prio) {
+			if (tp->prio == prio) {
+				if (!nprio ||
+				    (tp->protocol != protocol && protocol))
+					goto errout;
+			} else
+				tp = NULL;
+			break;
+		}
+	}
+
+	if (tp == NULL) {
+		/* Proto-tcf does not exist, create new one */
+
+		if (tca[TCA_KIND] == NULL || !protocol)
+			goto errout;
+
+		err = -ENOENT;
+		if (n->nlmsg_type != RTM_NEWTFILTER ||
+		    !(n->nlmsg_flags & NLM_F_CREATE))
+			goto errout;
+
+
+		/* Create new proto tcf */
+
+		err = -ENOBUFS;
+		tp = kzalloc(sizeof(*tp), GFP_KERNEL);
+		if (tp == NULL)
+			goto errout;
+		err = -ENOENT;
+		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
+		if (tp_ops == NULL) {
+#ifdef CONFIG_MODULES
+			struct nlattr *kind = tca[TCA_KIND];
+			char name[IFNAMSIZ];
+
+			if (kind != NULL &&
+			    nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
+				rtnl_unlock();
+				request_module("cls_%s", name);
+				rtnl_lock();
+				tp_ops = tcf_proto_lookup_ops(kind);
+				/* We dropped the RTNL semaphore in order to
+				 * perform the module load.  So, even if we
+				 * succeeded in loading the module we have to
+				 * replay the request.  We indicate this using
+				 * -EAGAIN.
+				 */
+				if (tp_ops != NULL) {
+					module_put(tp_ops->owner);
+					err = -EAGAIN;
+				}
+			}
+#endif
+			kfree(tp);
+			goto errout;
+		}
+		tp->ops = tp_ops;
+		tp->protocol = protocol;
+		tp->prio = nprio ? :
+			       TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
+		tp->q = q;
+		tp->classify = tp_ops->classify;
+		tp->classid = parent;
+
+		err = tp_ops->init(tp);
+		if (err != 0) {
+			module_put(tp_ops->owner);
+			kfree(tp);
+			goto errout;
+		}
+
+		tp_created = 1;
+
+	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
+		goto errout;
+
+	fh = tp->ops->get(tp, t->tcm_handle);
+
+	if (fh == 0) {
+		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
+			struct tcf_proto *next = rtnl_dereference(tp->next);
+
+			RCU_INIT_POINTER(*back, next);
+
+			tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
+			tcf_destroy(tp, true);
+			err = 0;
+			goto errout;
+		}
+
+		err = -ENOENT;
+		if (n->nlmsg_type != RTM_NEWTFILTER ||
+		    !(n->nlmsg_flags & NLM_F_CREATE))
+			goto errout;
+	} else {
+		switch (n->nlmsg_type) {
+		case RTM_NEWTFILTER:
+			err = -EEXIST;
+			if (n->nlmsg_flags & NLM_F_EXCL) {
+				if (tp_created)
+					tcf_destroy(tp, true);
+				goto errout;
+			}
+			break;
+		case RTM_DELTFILTER:
+			err = tp->ops->delete(tp, fh);
+			if (err == 0) {
+				struct tcf_proto *next = rtnl_dereference(tp->next);
+
+				tfilter_notify(net, skb, n, tp, fh, RTM_DELTFILTER);
+				if (tcf_destroy(tp, false))
+					RCU_INIT_POINTER(*back, next);
+			}
+			goto errout;
+		case RTM_GETTFILTER:
+			err = tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
+			goto errout;
+		default:
+			err = -EINVAL;
+			goto errout;
+		}
+	}
+
+	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
+			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
+	if (err == 0) {
+		if (tp_created) {
+			RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));
+			rcu_assign_pointer(*back, tp);
+		}
+		tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER);
+	} else {
+		if (tp_created)
+			tcf_destroy(tp, true);
+	}
+
+errout:
+	if (cl)
+		cops->put(q, cl);
+	if (err == -EAGAIN)
+		/* Replay the request. */
+		goto replay;
+	return err;
+}
+
+static int tcf_fill_node(struct net *net, struct sk_buff *skb, struct tcf_proto *tp,
+			 unsigned long fh, u32 portid, u32 seq, u16 flags, int event)
+{
+	struct tcmsg *tcm;
+	struct nlmsghdr  *nlh;
+	unsigned char *b = skb_tail_pointer(skb);
+
+	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
+	if (!nlh)
+		goto out_nlmsg_trim;
+	tcm = nlmsg_data(nlh);
+	tcm->tcm_family = AF_UNSPEC;
+	tcm->tcm__pad1 = 0;
+	tcm->tcm__pad2 = 0;
+	tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
+	tcm->tcm_parent = tp->classid;
+	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
+	if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
+		goto nla_put_failure;
+	tcm->tcm_handle = fh;
+	if (RTM_DELTFILTER != event) {
+		tcm->tcm_handle = 0;
+		if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
+			goto nla_put_failure;
+	}
+	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+	return skb->len;
+
+out_nlmsg_trim:
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static int tfilter_notify(struct net *net, struct sk_buff *oskb,
+			  struct nlmsghdr *n, struct tcf_proto *tp,
+			  unsigned long fh, int event)
+{
+	struct sk_buff *skb;
+	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq, 0, event) <= 0) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
+			      n->nlmsg_flags & NLM_F_ECHO);
+}
+
+struct tcf_dump_args {
+	struct tcf_walker w;
+	struct sk_buff *skb;
+	struct netlink_callback *cb;
+};
+
+static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
+			 struct tcf_walker *arg)
+{
+	struct tcf_dump_args *a = (void *)arg;
+	struct net *net = sock_net(a->skb->sk);
+
+	return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
+			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
+}
+
+/* called with RTNL */
+static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	int t;
+	int s_t;
+	struct net_device *dev;
+	struct Qdisc *q;
+	struct tcf_proto *tp, __rcu **chain;
+	struct tcmsg *tcm = nlmsg_data(cb->nlh);
+	unsigned long cl = 0;
+	const struct Qdisc_class_ops *cops;
+	struct tcf_dump_args arg;
+
+	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
+		return skb->len;
+	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
+	if (!dev)
+		return skb->len;
+
+	if (!tcm->tcm_parent)
+		q = dev->qdisc;
+	else
+		q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
+	if (!q)
+		goto out;
+	cops = q->ops->cl_ops;
+	if (!cops)
+		goto errout;
+	if (cops->tcf_chain == NULL)
+		goto errout;
+	if (TC_H_MIN(tcm->tcm_parent)) {
+		cl = cops->get(q, tcm->tcm_parent);
+		if (cl == 0)
+			goto errout;
+	}
+	chain = cops->tcf_chain(q, cl);
+	if (chain == NULL)
+		goto errout;
+
+	s_t = cb->args[0];
+
+	for (tp = rtnl_dereference(*chain), t = 0;
+	     tp; tp = rtnl_dereference(tp->next), t++) {
+		if (t < s_t)
+			continue;
+		if (TC_H_MAJ(tcm->tcm_info) &&
+		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
+			continue;
+		if (TC_H_MIN(tcm->tcm_info) &&
+		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
+			continue;
+		if (t > s_t)
+			memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
+		if (cb->args[1] == 0) {
+			if (tcf_fill_node(net, skb, tp, 0, NETLINK_CB(cb->skb).portid,
+					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					  RTM_NEWTFILTER) <= 0)
+				break;
+
+			cb->args[1] = 1;
+		}
+		if (tp->ops->walk == NULL)
+			continue;
+		arg.w.fn = tcf_node_dump;
+		arg.skb = skb;
+		arg.cb = cb;
+		arg.w.stop = 0;
+		arg.w.skip = cb->args[1] - 1;
+		arg.w.count = 0;
+		tp->ops->walk(tp, &arg.w);
+		cb->args[1] = arg.w.count + 1;
+		if (arg.w.stop)
+			break;
+	}
+
+	cb->args[0] = t;
+
+errout:
+	if (cl)
+		cops->put(q, cl);
+out:
+	return skb->len;
+}
+
+void tcf_exts_destroy(struct tcf_exts *exts)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	tcf_action_destroy(&exts->actions, TCA_ACT_UNBIND);
+	INIT_LIST_HEAD(&exts->actions);
+#endif
+}
+EXPORT_SYMBOL(tcf_exts_destroy);
+
+int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
+		  struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	{
+		struct tc_action *act;
+
+		INIT_LIST_HEAD(&exts->actions);
+		if (exts->police && tb[exts->police]) {
+			act = tcf_action_init_1(net, tb[exts->police], rate_tlv,
+						"police", ovr,
+						TCA_ACT_BIND);
+			if (IS_ERR(act))
+				return PTR_ERR(act);
+
+			act->type = exts->type = TCA_OLD_COMPAT;
+			list_add(&act->list, &exts->actions);
+		} else if (exts->action && tb[exts->action]) {
+			int err;
+			err = tcf_action_init(net, tb[exts->action], rate_tlv,
+					      NULL, ovr,
+					      TCA_ACT_BIND, &exts->actions);
+			if (err)
+				return err;
+		}
+	}
+#else
+	if ((exts->action && tb[exts->action]) ||
+	    (exts->police && tb[exts->police]))
+		return -EOPNOTSUPP;
+#endif
+
+	return 0;
+}
+EXPORT_SYMBOL(tcf_exts_validate);
+
+void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
+		     struct tcf_exts *src)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	LIST_HEAD(tmp);
+	tcf_tree_lock(tp);
+	list_splice_init(&dst->actions, &tmp);
+	list_splice(&src->actions, &dst->actions);
+	dst->type = src->type;
+	tcf_tree_unlock(tp);
+	tcf_action_destroy(&tmp, TCA_ACT_UNBIND);
+#endif
+}
+EXPORT_SYMBOL(tcf_exts_change);
+
+#define tcf_exts_first_act(ext)					\
+	list_first_entry_or_null(&(exts)->actions,		\
+				 struct tc_action, list)
+
+int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	struct nlattr *nest;
+
+	if (exts->action && !list_empty(&exts->actions)) {
+		/*
+		 * again for backward compatible mode - we want
+		 * to work with both old and new modes of entering
+		 * tc data even if iproute2  was newer - jhs
+		 */
+		if (exts->type != TCA_OLD_COMPAT) {
+			nest = nla_nest_start(skb, exts->action);
+			if (nest == NULL)
+				goto nla_put_failure;
+			if (tcf_action_dump(skb, &exts->actions, 0, 0) < 0)
+				goto nla_put_failure;
+			nla_nest_end(skb, nest);
+		} else if (exts->police) {
+			struct tc_action *act = tcf_exts_first_act(exts);
+			nest = nla_nest_start(skb, exts->police);
+			if (nest == NULL || !act)
+				goto nla_put_failure;
+			if (tcf_action_dump_old(skb, act, 0, 0) < 0)
+				goto nla_put_failure;
+			nla_nest_end(skb, nest);
+		}
+	}
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(skb, nest);
+	return -1;
+#else
+	return 0;
+#endif
+}
+EXPORT_SYMBOL(tcf_exts_dump);
+
+
+int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	struct tc_action *a = tcf_exts_first_act(exts);
+	if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
+		return -1;
+#endif
+	return 0;
+}
+EXPORT_SYMBOL(tcf_exts_dump_stats);
+
+static int __init tc_filter_init(void)
+{
+	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
+	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
+		      tc_dump_tfilter, NULL);
+
+	return 0;
+}
+
+subsys_initcall(tc_filter_init);