diff options
Diffstat (limited to 'kernel/net/sched/cls_route.c')
| -rw-r--r-- | kernel/net/sched/cls_route.c | 674 |
1 files changed, 674 insertions, 0 deletions
diff --git a/kernel/net/sched/cls_route.c b/kernel/net/sched/cls_route.c new file mode 100644 index 000000000..08a3b0a6f --- /dev/null +++ b/kernel/net/sched/cls_route.c @@ -0,0 +1,674 @@ +/* + * net/sched/cls_route.c ROUTE4 classifier. + * + * 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> + */ + +#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_head rcu; +}; + +#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_is_available(&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; + if (head == NULL) + goto old_method; + + 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; + +old_method: + 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 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 unsigned long 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; + + if (!head) + return 0; + + h1 = to_hash(handle); + if (h1 > 256) + return 0; + + h2 = from_hash(handle >> 16); + if (h2 > 32) + return 0; + + 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 (unsigned long)f; + } + return 0; +} + +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 rcu_head *head) +{ + struct route4_filter *f = container_of(head, struct route4_filter, rcu); + + tcf_exts_destroy(&f->exts); + kfree(f); +} + +static bool route4_destroy(struct tcf_proto *tp, bool force) +{ + struct route4_head *head = rtnl_dereference(tp->root); + int h1, h2; + + if (head == NULL) + return true; + + if (!force) { + for (h1 = 0; h1 <= 256; h1++) { + if (rcu_access_pointer(head->table[h1])) + return false; + } + } + + 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); + call_rcu(&f->rcu, route4_delete_filter); + } + } + RCU_INIT_POINTER(head->table[h1], NULL); + kfree_rcu(b, rcu); + } + } + RCU_INIT_POINTER(tp->root, NULL); + kfree_rcu(head, rcu); + return true; +} + +static int route4_delete(struct tcf_proto *tp, unsigned long arg) +{ + struct route4_head *head = rtnl_dereference(tp->root); + struct route4_filter *f = (struct route4_filter *)arg; + struct route4_filter __rcu **fp; + struct route4_filter *nf; + struct route4_bucket *b; + unsigned int h = 0; + int i; + + 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); + call_rcu(&f->rcu, route4_delete_filter); + + /* Strip RTNL protected tree */ + for (i = 0; i <= 32; i++) { + struct route4_filter *rt; + + rt = rtnl_dereference(b->ht[i]); + if (rt) + return 0; + } + + /* OK, session has no flows */ + RCU_INIT_POINTER(head->table[to_hash(h)], NULL); + kfree_rcu(b, rcu); + + return 0; + } + } + 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) +{ + int err; + u32 id = 0, to = 0, nhandle = 0x8000; + struct route4_filter *fp; + unsigned int h1; + struct route4_bucket *b; + struct tcf_exts e; + + tcf_exts_init(&e, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE); + err = tcf_exts_validate(net, tp, tb, est, &e, ovr); + if (err < 0) + return err; + + err = -EINVAL; + if (tb[TCA_ROUTE4_TO]) { + if (new && handle & 0x8000) + goto errout; + to = nla_get_u32(tb[TCA_ROUTE4_TO]); + if (to > 0xFF) + goto errout; + nhandle = to; + } + + if (tb[TCA_ROUTE4_FROM]) { + if (tb[TCA_ROUTE4_IIF]) + goto errout; + id = nla_get_u32(tb[TCA_ROUTE4_FROM]); + if (id > 0xFF) + goto errout; + nhandle |= id << 16; + } else if (tb[TCA_ROUTE4_IIF]) { + id = nla_get_u32(tb[TCA_ROUTE4_IIF]); + if (id > 0x7FFF) + goto errout; + nhandle |= (id | 0x8000) << 16; + } else + nhandle |= 0xFFFF << 16; + + if (handle && new) { + nhandle |= handle & 0x7F00; + if (nhandle != handle) + goto errout; + } + + h1 = to_hash(nhandle); + b = rtnl_dereference(head->table[h1]); + if (!b) { + err = -ENOBUFS; + b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL); + if (b == NULL) + goto errout; + + rcu_assign_pointer(head->table[h1], b); + } else { + unsigned int h2 = from_hash(nhandle >> 16); + + err = -EEXIST; + for (fp = rtnl_dereference(b->ht[h2]); + fp; + fp = rtnl_dereference(fp->next)) + if (fp->handle == f->handle) + goto errout; + } + + 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); + } + + tcf_exts_change(tp, &f->exts, &e); + + return 0; +errout: + tcf_exts_destroy(&e); + return err; +} + +static int route4_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 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(tb, TCA_ROUTE4_MAX, opt, route4_policy); + if (err < 0) + return err; + + fold = (struct route4_filter *)*arg; + if (fold && handle && fold->handle != handle) + return -EINVAL; + + err = -ENOBUFS; + f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL); + if (!f) + goto errout; + + tcf_exts_init(&f->exts, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE); + 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); + 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; + + netif_keep_dst(qdisc_dev(tp->q)); + 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 = (unsigned long)f; + if (fold) { + tcf_unbind_filter(tp, &fold->res); + call_rcu(&fold->rcu, route4_delete_filter); + } + return 0; + +errout: + kfree(f); + return err; +} + +static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg) +{ + struct route4_head *head = rtnl_dereference(tp->root); + unsigned int h, h1; + + if (head == NULL) + arg->stop = 1; + + if (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, (unsigned long)f, arg) < 0) { + arg->stop = 1; + return; + } + arg->count++; + } + } + } + } +} + +static int route4_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, + struct sk_buff *skb, struct tcmsg *t) +{ + struct route4_filter *f = (struct route4_filter *)fh; + struct nlattr *nest; + u32 id; + + if (f == NULL) + return skb->len; + + t->tcm_handle = f->handle; + + nest = nla_nest_start(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 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, + .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"); 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