/* * 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; err = tcf_exts_init(&e, TCA_FW_ACT, TCA_FW_POLICE); if (err < 0) return err; err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr); if (err < 0) goto errout; 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; err = tcf_exts_init(&fnew->exts, TCA_FW_ACT, TCA_FW_POLICE); if (err < 0) { kfree(fnew); return err; } err = fw_change_attrs(net, tp, fnew, tb, tca, base, ovr); if (err < 0) { tcf_exts_destroy(&fnew->exts); 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; err = tcf_exts_init(&f->exts, TCA_FW_ACT, TCA_FW_POLICE); if (err < 0) goto errout; 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: tcf_exts_destroy(&f->exts); 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");