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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/sched/cls_api.c
Initial import
Diffstat (limited to 'net/sched/cls_api.c')
-rw-r--r--net/sched/cls_api.c634
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);