// SPDX-License-Identifier: GPL-2.0-or-later /* * net/sched/cls_route.c ROUTE4 classifier. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> */ #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/dst.h> #include <net/route.h> #include <net/netlink.h> #include <net/act_api.h> #include <net/pkt_cls.h> /* * 1. For now we assume that route tags < 256. * It allows to use direct table lookups, instead of hash tables. * 2. For now we assume that "from TAG" and "fromdev DEV" statements * are mutually exclusive. * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX" */ struct route4_fastmap { struct route4_filter *filter; u32 id; int iif; }; struct route4_head { struct route4_fastmap fastmap[16]; struct route4_bucket __rcu *table[256 + 1]; struct rcu_head rcu; }; struct route4_bucket { /* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */ struct route4_filter __rcu *ht[16 + 16 + 1]; struct rcu_head rcu; }; struct route4_filter { struct route4_filter __rcu *next; u32 id; int iif; struct tcf_result res; struct tcf_exts exts; u32 handle; struct route4_bucket *bkt; struct tcf_proto *tp; struct rcu_work rwork; }; #define ROUTE4_FAILURE ((struct route4_filter *)(-1L)) static inline int route4_fastmap_hash(u32 id, int iif) { return id & 0xF; } static DEFINE_SPINLOCK(fastmap_lock); static void route4_reset_fastmap(struct route4_head *head) { spin_lock_bh(&fastmap_lock); memset(head->fastmap, 0, sizeof(head->fastmap)); spin_unlock_bh(&fastmap_lock); } static void route4_set_fastmap(struct route4_head *head, u32 id, int iif, struct route4_filter *f) { int h = route4_fastmap_hash(id, iif); /* fastmap updates must look atomic to aling id, iff, filter */ spin_lock_bh(&fastmap_lock); head->fastmap[h].id = id; head->fastmap[h].iif = iif; head->fastmap[h].filter = f; spin_unlock_bh(&fastmap_lock); } static inline int route4_hash_to(u32 id) { return id & 0xFF; } static inline int route4_hash_from(u32 id) { return (id >> 16) & 0xF; } static inline int route4_hash_iif(int iif) { return 16 + ((iif >> 16) & 0xF); } static inline int route4_hash_wild(void) { return 32; } #define ROUTE4_APPLY_RESULT() \ { \ *res = f->res; \ if (tcf_exts_has_actions(&f->exts)) { \ int r = tcf_exts_exec(skb, &f->exts, res); \ if (r < 0) { \ dont_cache = 1; \ continue; \ } \ return r; \ } else if (!dont_cache) \ route4_set_fastmap(head, id, iif, f); \ return 0; \ } static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res) { struct route4_head *head = rcu_dereference_bh(tp->root); struct dst_entry *dst; struct route4_bucket *b; struct route4_filter *f; u32 id, h; int iif, dont_cache = 0; dst = skb_dst(skb); if (!dst) goto failure; id = dst->tclassid; iif = inet_iif(skb); h = route4_fastmap_hash(id, iif); spin_lock(&fastmap_lock); if (id == head->fastmap[h].id && iif == head->fastmap[h].iif && (f = head->fastmap[h].filter) != NULL) { if (f == ROUTE4_FAILURE) { spin_unlock(&fastmap_lock); goto failure; } *res = f->res; spin_unlock(&fastmap_lock); return 0; } spin_unlock(&fastmap_lock); h = route4_hash_to(id); restart: b = rcu_dereference_bh(head->table[h]); if (b) { for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]); f; f = rcu_dereference_bh(f->next)) if (f->id == id) ROUTE4_APPLY_RESULT(); for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]); f; f = rcu_dereference_bh(f->next)) if (f->iif == iif) ROUTE4_APPLY_RESULT(); for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]); f; f = rcu_dereference_bh(f->next)) ROUTE4_APPLY_RESULT(); } if (h < 256) { h = 256; id &= ~0xFFFF; goto restart; } if (!dont_cache) route4_set_fastmap(head, id, iif, ROUTE4_FAILURE); failure: return -1; } static inline u32 to_hash(u32 id) { u32 h = id & 0xFF; if (id & 0x8000) h += 256; return h; } static inline u32 from_hash(u32 id) { id &= 0xFFFF; if (id == 0xFFFF) return 32; if (!(id & 0x8000)) { if (id > 255) return 256; return id & 0xF; } return 16 + (id & 0xF); } static void *route4_get(struct tcf_proto *tp, u32 handle) { struct route4_head *head = rtnl_dereference(tp->root); struct route4_bucket *b; struct route4_filter *f; unsigned int h1, h2; h1 = to_hash(handle); if (h1 > 256) return NULL; h2 = from_hash(handle >> 16); if (h2 > 32) return NULL; b = rtnl_dereference(head->table[h1]); if (b) { for (f = rtnl_dereference(b->ht[h2]); f; f = rtnl_dereference(f->next)) if (f->handle == handle) return f; } return NULL; } static int route4_init(struct tcf_proto *tp) { struct route4_head *head; head = kzalloc(sizeof(struct route4_head), GFP_KERNEL); if (head == NULL) return -ENOBUFS; rcu_assign_pointer(tp->root, head); return 0; } static void __route4_delete_filter(struct route4_filter *f) { tcf_exts_destroy(&f->exts); tcf_exts_put_net(&f->exts); kfree(f); } static void route4_delete_filter_work(struct work_struct *work) { struct route4_filter *f = container_of(to_rcu_work(work), struct route4_filter, rwork); rtnl_lock(); __route4_delete_filter(f); rtnl_unlock(); } static void route4_queue_work(struct route4_filter *f) { tcf_queue_work(&f->rwork, route4_delete_filter_work); } static void route4_destroy(struct tcf_proto *tp, bool rtnl_held, struct netlink_ext_ack *extack) { struct route4_head *head = rtnl_dereference(tp->root); int h1, h2; if (head == NULL) return; for (h1 = 0; h1 <= 256; h1++) { struct route4_bucket *b; b = rtnl_dereference(head->table[h1]); if (b) { for (h2 = 0; h2 <= 32; h2++) { struct route4_filter *f; while ((f = rtnl_dereference(b->ht[h2])) != NULL) { struct route4_filter *next; next = rtnl_dereference(f->next); RCU_INIT_POINTER(b->ht[h2], next); tcf_unbind_filter(tp, &f->res); if (tcf_exts_get_net(&f->exts)) route4_queue_work(f); else __route4_delete_filter(f); } } RCU_INIT_POINTER(head->table[h1], NULL); kfree_rcu(b, rcu); } } kfree_rcu(head, rcu); } static int route4_delete(struct tcf_proto *tp, void *arg, bool *last, bool rtnl_held, struct netlink_ext_ack *extack) { struct route4_head *head = rtnl_dereference(tp->root); struct route4_filter *f = arg; struct route4_filter __rcu **fp; struct route4_filter *nf; struct route4_bucket *b; unsigned int h = 0; int i, h1; if (!head || !f) return -EINVAL; h = f->handle; b = f->bkt; fp = &b->ht[from_hash(h >> 16)]; for (nf = rtnl_dereference(*fp); nf; fp = &nf->next, nf = rtnl_dereference(*fp)) { if (nf == f) { /* unlink it */ RCU_INIT_POINTER(*fp, rtnl_dereference(f->next)); /* Remove any fastmap lookups that might ref filter * notice we unlink'd the filter so we can't get it * back in the fastmap. */ route4_reset_fastmap(head); /* Delete it */ tcf_unbind_filter(tp, &f->res); tcf_exts_get_net(&f->exts); tcf_queue_work(&f->rwork, route4_delete_filter_work); /* Strip RTNL protected tree */ for (i = 0; i <= 32; i++) { struct route4_filter *rt; rt = rtnl_dereference(b->ht[i]); if (rt) goto out; } /* OK, session has no flows */ RCU_INIT_POINTER(head->table[to_hash(h)], NULL); kfree_rcu(b, rcu); break; } } out: *last = true; for (h1 = 0; h1 <= 256; h1++) { if (rcu_access_pointer(head->table[h1])) { *last = false; break; } } return 0; } static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = { [TCA_ROUTE4_CLASSID] = { .type = NLA_U32 }, [TCA_ROUTE4_TO] = { .type = NLA_U32 }, [TCA_ROUTE4_FROM] = { .type = NLA_U32 }, [TCA_ROUTE4_IIF] = { .type = NLA_U32 }, }; static int route4_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, struct route4_filter *f, u32 handle, struct route4_head *head, struct nlattr **tb, struct nlattr *est, int new, bool ovr, struct netlink_ext_ack *extack) { u32 id = 0, to = 0, nhandle = 0x8000; struct route4_filter *fp; unsigned int h1; struct route4_bucket *b; int err; err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true, extack); if (err < 0) return err; if (tb[TCA_ROUTE4_TO]) { if (new && handle & 0x8000) return -EINVAL; to = nla_get_u32(tb[TCA_ROUTE4_TO]); if (to > 0xFF) return -EINVAL; nhandle = to; } if (tb[TCA_ROUTE4_FROM]) { if (tb[TCA_ROUTE4_IIF]) return -EINVAL; id = nla_get_u32(tb[TCA_ROUTE4_FROM]); if (id > 0xFF) return -EINVAL; nhandle |= id << 16; } else if (tb[TCA_ROUTE4_IIF]) { id = nla_get_u32(tb[TCA_ROUTE4_IIF]); if (id > 0x7FFF) return -EINVAL; nhandle |= (id | 0x8000) << 16; } else nhandle |= 0xFFFF << 16; if (handle && new) { nhandle |= handle & 0x7F00; if (nhandle != handle) return -EINVAL; } h1 = to_hash(nhandle); b = rtnl_dereference(head->table[h1]); if (!b) { b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL); if (b == NULL) return -ENOBUFS; rcu_assign_pointer(head->table[h1], b); } else { unsigned int h2 = from_hash(nhandle >> 16); for (fp = rtnl_dereference(b->ht[h2]); fp; fp = rtnl_dereference(fp->next)) if (fp->handle == f->handle) return -EEXIST; } if (tb[TCA_ROUTE4_TO]) f->id = to; if (tb[TCA_ROUTE4_FROM]) f->id = to | id<<16; else if (tb[TCA_ROUTE4_IIF]) f->iif = id; f->handle = nhandle; f->bkt = b; f->tp = tp; if (tb[TCA_ROUTE4_CLASSID]) { f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]); tcf_bind_filter(tp, &f->res, base); } return 0; } static int route4_change(struct net *net, struct sk_buff *in_skb, struct tcf_proto *tp, unsigned long base, u32 handle, struct nlattr **tca, void **arg, bool ovr, bool rtnl_held, struct netlink_ext_ack *extack) { struct route4_head *head = rtnl_dereference(tp->root); struct route4_filter __rcu **fp; struct route4_filter *fold, *f1, *pfp, *f = NULL; struct route4_bucket *b; struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_ROUTE4_MAX + 1]; unsigned int h, th; int err; bool new = true; if (opt == NULL) return handle ? -EINVAL : 0; err = nla_parse_nested_deprecated(tb, TCA_ROUTE4_MAX, opt, route4_policy, NULL); if (err < 0) return err; fold = *arg; if (fold && handle && fold->handle != handle) return -EINVAL; err = -ENOBUFS; f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL); if (!f) goto errout; err = tcf_exts_init(&f->exts, net, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE); if (err < 0) goto errout; if (fold) { f->id = fold->id; f->iif = fold->iif; f->res = fold->res; f->handle = fold->handle; f->tp = fold->tp; f->bkt = fold->bkt; new = false; } err = route4_set_parms(net, tp, base, f, handle, head, tb, tca[TCA_RATE], new, ovr, extack); if (err < 0) goto errout; h = from_hash(f->handle >> 16); fp = &f->bkt->ht[h]; for (pfp = rtnl_dereference(*fp); (f1 = rtnl_dereference(*fp)) != NULL; fp = &f1->next) if (f->handle < f1->handle) break; tcf_block_netif_keep_dst(tp->chain->block); rcu_assign_pointer(f->next, f1); rcu_assign_pointer(*fp, f); if (fold && fold->handle && f->handle != fold->handle) { th = to_hash(fold->handle); h = from_hash(fold->handle >> 16); b = rtnl_dereference(head->table[th]); if (b) { fp = &b->ht[h]; for (pfp = rtnl_dereference(*fp); pfp; fp = &pfp->next, pfp = rtnl_dereference(*fp)) { if (pfp == f) { *fp = f->next; break; } } } } route4_reset_fastmap(head); *arg = f; if (fold) { tcf_unbind_filter(tp, &fold->res); tcf_exts_get_net(&fold->exts); tcf_queue_work(&fold->rwork, route4_delete_filter_work); } return 0; errout: if (f) tcf_exts_destroy(&f->exts); kfree(f); return err; } static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg, bool rtnl_held) { struct route4_head *head = rtnl_dereference(tp->root); unsigned int h, h1; if (head == NULL || arg->stop) return; for (h = 0; h <= 256; h++) { struct route4_bucket *b = rtnl_dereference(head->table[h]); if (b) { for (h1 = 0; h1 <= 32; h1++) { struct route4_filter *f; for (f = rtnl_dereference(b->ht[h1]); f; f = rtnl_dereference(f->next)) { if (arg->count < arg->skip) { arg->count++; continue; } if (arg->fn(tp, f, arg) < 0) { arg->stop = 1; return; } arg->count++; } } } } } static int route4_dump(struct net *net, struct tcf_proto *tp, void *fh, struct sk_buff *skb, struct tcmsg *t, bool rtnl_held) { struct route4_filter *f = fh; struct nlattr *nest; u32 id; if (f == NULL) return skb->len; t->tcm_handle = f->handle; nest = nla_nest_start_noflag(skb, TCA_OPTIONS); if (nest == NULL) goto nla_put_failure; if (!(f->handle & 0x8000)) { id = f->id & 0xFF; if (nla_put_u32(skb, TCA_ROUTE4_TO, id)) goto nla_put_failure; } if (f->handle & 0x80000000) { if ((f->handle >> 16) != 0xFFFF && nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif)) goto nla_put_failure; } else { id = f->id >> 16; if (nla_put_u32(skb, TCA_ROUTE4_FROM, id)) goto nla_put_failure; } if (f->res.classid && nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid)) 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 void route4_bind_class(void *fh, u32 classid, unsigned long cl) { struct route4_filter *f = fh; if (f && f->res.classid == classid) f->res.class = cl; } static struct tcf_proto_ops cls_route4_ops __read_mostly = { .kind = "route", .classify = route4_classify, .init = route4_init, .destroy = route4_destroy, .get = route4_get, .change = route4_change, .delete = route4_delete, .walk = route4_walk, .dump = route4_dump, .bind_class = route4_bind_class, .owner = THIS_MODULE, }; static int __init init_route4(void) { return register_tcf_proto_ops(&cls_route4_ops); } static void __exit exit_route4(void) { unregister_tcf_proto_ops(&cls_route4_ops); } module_init(init_route4) module_exit(exit_route4) MODULE_LICENSE("GPL");