From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/sched/cls_api.c | 634 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 634 insertions(+) create mode 100644 net/sched/cls_api.c (limited to 'net/sched/cls_api.c') 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, + * + * Changes: + * + * Eduardo J. Blanco :990222: kmod support + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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); -- cgit v1.2.3