Initial import

1 files changed, 578 insertions, 0 deletions

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
new file mode 100644
index 000000000..a557dbaf5
--- /dev/null
+++ b/net/sched/cls_tcindex.c
@@ -0,0 +1,578 @@
+/*
+ * net/sched/cls_tcindex.c	Packet classifier for skb->tc_index
+ *
+ * Written 1998,1999 by Werner Almesberger, EPFL ICA
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <net/act_api.h>
+#include <net/netlink.h>
+#include <net/pkt_cls.h>
+
+/*
+ * Passing parameters to the root seems to be done more awkwardly than really
+ * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
+ * verified. FIXME.
+ */
+
+#define PERFECT_HASH_THRESHOLD	64	/* use perfect hash if not bigger */
+#define DEFAULT_HASH_SIZE	64	/* optimized for diffserv */
+
+
+struct tcindex_filter_result {
+	struct tcf_exts		exts;
+	struct tcf_result	res;
+};
+
+struct tcindex_filter {
+	u16 key;
+	struct tcindex_filter_result result;
+	struct tcindex_filter __rcu *next;
+	struct rcu_head rcu;
+};
+
+
+struct tcindex_data {
+	struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
+	struct tcindex_filter __rcu **h; /* imperfect hash; */
+	struct tcf_proto *tp;
+	u16 mask;		/* AND key with mask */
+	u32 shift;		/* shift ANDed key to the right */
+	u32 hash;		/* hash table size; 0 if undefined */
+	u32 alloc_hash;		/* allocated size */
+	u32 fall_through;	/* 0: only classify if explicit match */
+	struct rcu_head rcu;
+};
+
+static inline int
+tcindex_filter_is_set(struct tcindex_filter_result *r)
+{
+	return tcf_exts_is_predicative(&r->exts) || r->res.classid;
+}
+
+static struct tcindex_filter_result *
+tcindex_lookup(struct tcindex_data *p, u16 key)
+{
+	if (p->perfect) {
+		struct tcindex_filter_result *f = p->perfect + key;
+
+		return tcindex_filter_is_set(f) ? f : NULL;
+	} else if (p->h) {
+		struct tcindex_filter __rcu **fp;
+		struct tcindex_filter *f;
+
+		fp = &p->h[key % p->hash];
+		for (f = rcu_dereference_bh_rtnl(*fp);
+		     f;
+		     fp = &f->next, f = rcu_dereference_bh_rtnl(*fp))
+			if (f->key == key)
+				return &f->result;
+	}
+
+	return NULL;
+}
+
+
+static int tcindex_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+			    struct tcf_result *res)
+{
+	struct tcindex_data *p = rcu_dereference_bh(tp->root);
+	struct tcindex_filter_result *f;
+	int key = (skb->tc_index & p->mask) >> p->shift;
+
+	pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
+		 skb, tp, res, p);
+
+	f = tcindex_lookup(p, key);
+	if (!f) {
+		if (!p->fall_through)
+			return -1;
+		res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key);
+		res->class = 0;
+		pr_debug("alg 0x%x\n", res->classid);
+		return 0;
+	}
+	*res = f->res;
+	pr_debug("map 0x%x\n", res->classid);
+
+	return tcf_exts_exec(skb, &f->exts, res);
+}
+
+
+static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
+{
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcindex_filter_result *r;
+
+	pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
+	if (p->perfect && handle >= p->alloc_hash)
+		return 0;
+	r = tcindex_lookup(p, handle);
+	return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
+}
+
+static int tcindex_init(struct tcf_proto *tp)
+{
+	struct tcindex_data *p;
+
+	pr_debug("tcindex_init(tp %p)\n", tp);
+	p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
+	if (!p)
+		return -ENOMEM;
+
+	p->mask = 0xffff;
+	p->hash = DEFAULT_HASH_SIZE;
+	p->fall_through = 1;
+
+	rcu_assign_pointer(tp->root, p);
+	return 0;
+}
+
+static int
+tcindex_delete(struct tcf_proto *tp, unsigned long arg)
+{
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
+	struct tcindex_filter __rcu **walk;
+	struct tcindex_filter *f = NULL;
+
+	pr_debug("tcindex_delete(tp %p,arg 0x%lx),p %p\n", tp, arg, p);
+	if (p->perfect) {
+		if (!r->res.class)
+			return -ENOENT;
+	} else {
+		int i;
+
+		for (i = 0; i < p->hash; i++) {
+			walk = p->h + i;
+			for (f = rtnl_dereference(*walk); f;
+			     walk = &f->next, f = rtnl_dereference(*walk)) {
+				if (&f->result == r)
+					goto found;
+			}
+		}
+		return -ENOENT;
+
+found:
+		rcu_assign_pointer(*walk, rtnl_dereference(f->next));
+	}
+	tcf_unbind_filter(tp, &r->res);
+	tcf_exts_destroy(&r->exts);
+	if (f)
+		kfree_rcu(f, rcu);
+	return 0;
+}
+
+static int tcindex_destroy_element(struct tcf_proto *tp,
+				   unsigned long arg,
+				   struct tcf_walker *walker)
+{
+	return tcindex_delete(tp, arg);
+}
+
+static void __tcindex_destroy(struct rcu_head *head)
+{
+	struct tcindex_data *p = container_of(head, struct tcindex_data, rcu);
+
+	kfree(p->perfect);
+	kfree(p->h);
+	kfree(p);
+}
+
+static inline int
+valid_perfect_hash(struct tcindex_data *p)
+{
+	return  p->hash > (p->mask >> p->shift);
+}
+
+static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
+	[TCA_TCINDEX_HASH]		= { .type = NLA_U32 },
+	[TCA_TCINDEX_MASK]		= { .type = NLA_U16 },
+	[TCA_TCINDEX_SHIFT]		= { .type = NLA_U32 },
+	[TCA_TCINDEX_FALL_THROUGH]	= { .type = NLA_U32 },
+	[TCA_TCINDEX_CLASSID]		= { .type = NLA_U32 },
+};
+
+static void tcindex_filter_result_init(struct tcindex_filter_result *r)
+{
+	memset(r, 0, sizeof(*r));
+	tcf_exts_init(&r->exts, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
+}
+
+static void __tcindex_partial_destroy(struct rcu_head *head)
+{
+	struct tcindex_data *p = container_of(head, struct tcindex_data, rcu);
+
+	kfree(p->perfect);
+	kfree(p);
+}
+
+static int
+tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
+		  u32 handle, struct tcindex_data *p,
+		  struct tcindex_filter_result *r, struct nlattr **tb,
+		  struct nlattr *est, bool ovr)
+{
+	int err, balloc = 0;
+	struct tcindex_filter_result new_filter_result, *old_r = r;
+	struct tcindex_filter_result cr;
+	struct tcindex_data *cp, *oldp;
+	struct tcindex_filter *f = NULL; /* make gcc behave */
+	struct tcf_exts e;
+
+	tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
+	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
+	if (err < 0)
+		return err;
+
+	err = -ENOMEM;
+	/* tcindex_data attributes must look atomic to classifier/lookup so
+	 * allocate new tcindex data and RCU assign it onto root. Keeping
+	 * perfect hash and hash pointers from old data.
+	 */
+	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
+	if (!cp)
+		goto errout;
+
+	cp->mask = p->mask;
+	cp->shift = p->shift;
+	cp->hash = p->hash;
+	cp->alloc_hash = p->alloc_hash;
+	cp->fall_through = p->fall_through;
+	cp->tp = tp;
+
+	if (p->perfect) {
+		int i;
+
+		cp->perfect = kmemdup(p->perfect,
+				      sizeof(*r) * cp->hash, GFP_KERNEL);
+		if (!cp->perfect)
+			goto errout;
+		for (i = 0; i < cp->hash; i++)
+			tcf_exts_init(&cp->perfect[i].exts,
+				      TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
+		balloc = 1;
+	}
+	cp->h = p->h;
+
+	tcindex_filter_result_init(&new_filter_result);
+	tcindex_filter_result_init(&cr);
+	if (old_r)
+		cr.res = r->res;
+
+	if (tb[TCA_TCINDEX_HASH])
+		cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
+
+	if (tb[TCA_TCINDEX_MASK])
+		cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
+
+	if (tb[TCA_TCINDEX_SHIFT])
+		cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
+
+	err = -EBUSY;
+
+	/* Hash already allocated, make sure that we still meet the
+	 * requirements for the allocated hash.
+	 */
+	if (cp->perfect) {
+		if (!valid_perfect_hash(cp) ||
+		    cp->hash > cp->alloc_hash)
+			goto errout_alloc;
+	} else if (cp->h && cp->hash != cp->alloc_hash) {
+		goto errout_alloc;
+	}
+
+	err = -EINVAL;
+	if (tb[TCA_TCINDEX_FALL_THROUGH])
+		cp->fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
+
+	if (!cp->hash) {
+		/* Hash not specified, use perfect hash if the upper limit
+		 * of the hashing index is below the threshold.
+		 */
+		if ((cp->mask >> cp->shift) < PERFECT_HASH_THRESHOLD)
+			cp->hash = (cp->mask >> cp->shift) + 1;
+		else
+			cp->hash = DEFAULT_HASH_SIZE;
+	}
+
+	if (!cp->perfect && !cp->h)
+		cp->alloc_hash = cp->hash;
+
+	/* Note: this could be as restrictive as if (handle & ~(mask >> shift))
+	 * but then, we'd fail handles that may become valid after some future
+	 * mask change. While this is extremely unlikely to ever matter,
+	 * the check below is safer (and also more backwards-compatible).
+	 */
+	if (cp->perfect || valid_perfect_hash(cp))
+		if (handle >= cp->alloc_hash)
+			goto errout_alloc;
+
+
+	err = -ENOMEM;
+	if (!cp->perfect && !cp->h) {
+		if (valid_perfect_hash(cp)) {
+			int i;
+
+			cp->perfect = kcalloc(cp->hash, sizeof(*r), GFP_KERNEL);
+			if (!cp->perfect)
+				goto errout_alloc;
+			for (i = 0; i < cp->hash; i++)
+				tcf_exts_init(&cp->perfect[i].exts,
+					      TCA_TCINDEX_ACT,
+					      TCA_TCINDEX_POLICE);
+			balloc = 1;
+		} else {
+			struct tcindex_filter __rcu **hash;
+
+			hash = kcalloc(cp->hash,
+				       sizeof(struct tcindex_filter *),
+				       GFP_KERNEL);
+
+			if (!hash)
+				goto errout_alloc;
+
+			cp->h = hash;
+			balloc = 2;
+		}
+	}
+
+	if (cp->perfect)
+		r = cp->perfect + handle;
+	else
+		r = tcindex_lookup(cp, handle) ? : &new_filter_result;
+
+	if (r == &new_filter_result) {
+		f = kzalloc(sizeof(*f), GFP_KERNEL);
+		if (!f)
+			goto errout_alloc;
+		f->key = handle;
+		tcindex_filter_result_init(&f->result);
+		f->next = NULL;
+	}
+
+	if (tb[TCA_TCINDEX_CLASSID]) {
+		cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
+		tcf_bind_filter(tp, &cr.res, base);
+	}
+
+	if (old_r)
+		tcf_exts_change(tp, &r->exts, &e);
+	else
+		tcf_exts_change(tp, &cr.exts, &e);
+
+	if (old_r && old_r != r)
+		tcindex_filter_result_init(old_r);
+
+	oldp = p;
+	r->res = cr.res;
+	rcu_assign_pointer(tp->root, cp);
+
+	if (r == &new_filter_result) {
+		struct tcindex_filter *nfp;
+		struct tcindex_filter __rcu **fp;
+
+		tcf_exts_change(tp, &f->result.exts, &r->exts);
+
+		fp = cp->h + (handle % cp->hash);
+		for (nfp = rtnl_dereference(*fp);
+		     nfp;
+		     fp = &nfp->next, nfp = rtnl_dereference(*fp))
+				; /* nothing */
+
+		rcu_assign_pointer(*fp, f);
+	}
+
+	if (oldp)
+		call_rcu(&oldp->rcu, __tcindex_partial_destroy);
+	return 0;
+
+errout_alloc:
+	if (balloc == 1)
+		kfree(cp->perfect);
+	else if (balloc == 2)
+		kfree(cp->h);
+errout:
+	kfree(cp);
+	tcf_exts_destroy(&e);
+	return err;
+}
+
+static int
+tcindex_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 nlattr *opt = tca[TCA_OPTIONS];
+	struct nlattr *tb[TCA_TCINDEX_MAX + 1];
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
+	int err;
+
+	pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
+	    "p %p,r %p,*arg 0x%lx\n",
+	    tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
+
+	if (!opt)
+		return 0;
+
+	err = nla_parse_nested(tb, TCA_TCINDEX_MAX, opt, tcindex_policy);
+	if (err < 0)
+		return err;
+
+	return tcindex_set_parms(net, tp, base, handle, p, r, tb,
+				 tca[TCA_RATE], ovr);
+}
+
+static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
+{
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcindex_filter *f, *next;
+	int i;
+
+	pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
+	if (p->perfect) {
+		for (i = 0; i < p->hash; i++) {
+			if (!p->perfect[i].res.class)
+				continue;
+			if (walker->count >= walker->skip) {
+				if (walker->fn(tp,
+				    (unsigned long) (p->perfect+i), walker)
+				     < 0) {
+					walker->stop = 1;
+					return;
+				}
+			}
+			walker->count++;
+		}
+	}
+	if (!p->h)
+		return;
+	for (i = 0; i < p->hash; i++) {
+		for (f = rtnl_dereference(p->h[i]); f; f = next) {
+			next = rtnl_dereference(f->next);
+			if (walker->count >= walker->skip) {
+				if (walker->fn(tp, (unsigned long) &f->result,
+				    walker) < 0) {
+					walker->stop = 1;
+					return;
+				}
+			}
+			walker->count++;
+		}
+	}
+}
+
+static bool tcindex_destroy(struct tcf_proto *tp, bool force)
+{
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcf_walker walker;
+
+	if (!force)
+		return false;
+
+	pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
+	walker.count = 0;
+	walker.skip = 0;
+	walker.fn = tcindex_destroy_element;
+	tcindex_walk(tp, &walker);
+
+	RCU_INIT_POINTER(tp->root, NULL);
+	call_rcu(&p->rcu, __tcindex_destroy);
+	return true;
+}
+
+
+static int tcindex_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
+    struct sk_buff *skb, struct tcmsg *t)
+{
+	struct tcindex_data *p = rtnl_dereference(tp->root);
+	struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
+	struct nlattr *nest;
+
+	pr_debug("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p\n",
+		 tp, fh, skb, t, p, r);
+	pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
+
+	nest = nla_nest_start(skb, TCA_OPTIONS);
+	if (nest == NULL)
+		goto nla_put_failure;
+
+	if (!fh) {
+		t->tcm_handle = ~0; /* whatever ... */
+		if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
+		    nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
+		    nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
+		    nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
+			goto nla_put_failure;
+		nla_nest_end(skb, nest);
+	} else {
+		if (p->perfect) {
+			t->tcm_handle = r - p->perfect;
+		} else {
+			struct tcindex_filter *f;
+			struct tcindex_filter __rcu **fp;
+			int i;
+
+			t->tcm_handle = 0;
+			for (i = 0; !t->tcm_handle && i < p->hash; i++) {
+				fp = &p->h[i];
+				for (f = rtnl_dereference(*fp);
+				     !t->tcm_handle && f;
+				     fp = &f->next, f = rtnl_dereference(*fp)) {
+					if (&f->result == r)
+						t->tcm_handle = f->key;
+				}
+			}
+		}
+		pr_debug("handle = %d\n", t->tcm_handle);
+		if (r->res.class &&
+		    nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
+			goto nla_put_failure;
+
+		if (tcf_exts_dump(skb, &r->exts) < 0)
+			goto nla_put_failure;
+		nla_nest_end(skb, nest);
+
+		if (tcf_exts_dump_stats(skb, &r->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_tcindex_ops __read_mostly = {
+	.kind		=	"tcindex",
+	.classify	=	tcindex_classify,
+	.init		=	tcindex_init,
+	.destroy	=	tcindex_destroy,
+	.get		=	tcindex_get,
+	.change		=	tcindex_change,
+	.delete		=	tcindex_delete,
+	.walk		=	tcindex_walk,
+	.dump		=	tcindex_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init init_tcindex(void)
+{
+	return register_tcf_proto_ops(&cls_tcindex_ops);
+}
+
+static void __exit exit_tcindex(void)
+{
+	unregister_tcf_proto_ops(&cls_tcindex_ops);
+}
+
+module_init(init_tcindex)
+module_exit(exit_tcindex)
+MODULE_LICENSE("GPL");