1 files changed, 512 insertions, 0 deletions

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
new file mode 100644
index 0000000..7a7bff5
--- /dev/null
+++ b/net/sched/cls_tcindex.c
@@ -0,0 +1,512 @@
+/*
+ * 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 <net/act_api.h>
+#include <net/netlink.h>
+#include <net/pkt_cls.h>
+
+
+/*
+ * Not quite sure if we need all the xchgs Alexey uses when accessing things.
+ * Can always add them later ... :)
+ */
+
+/*
+ * 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 */
+
+
+#define	PRIV(tp)	((struct tcindex_data *) (tp)->root)
+
+
+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 *next;
+};
+
+
+struct tcindex_data {
+	struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
+	struct tcindex_filter **h; /* imperfect hash; only used if !perfect;
+				      NULL if unused */
+	u16 mask;		/* AND key with mask */
+	int shift;		/* shift ANDed key to the right */
+	int hash;		/* hash table size; 0 if undefined */
+	int alloc_hash;		/* allocated size */
+	int fall_through;	/* 0: only classify if explicit match */
+};
+
+static const struct tcf_ext_map tcindex_ext_map = {
+	.police = TCA_TCINDEX_POLICE,
+	.action = TCA_TCINDEX_ACT
+};
+
+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)
+{
+	struct tcindex_filter *f;
+
+	if (p->perfect)
+		return tcindex_filter_is_set(p->perfect + key) ?
+			p->perfect + key : NULL;
+	else if (p->h) {
+		for (f = p->h[key % p->hash]; f; f = f->next)
+			if (f->key == key)
+				return &f->result;
+	}
+
+	return NULL;
+}
+
+
+static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp,
+			    struct tcf_result *res)
+{
+	struct tcindex_data *p = PRIV(tp);
+	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 = PRIV(tp);
+	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 void tcindex_put(struct tcf_proto *tp, unsigned long f)
+{
+	pr_debug("tcindex_put(tp %p,f 0x%lx)\n", tp, f);
+}
+
+
+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;
+
+	tp->root = p;
+	return 0;
+}
+
+
+static int
+__tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
+{
+	struct tcindex_data *p = PRIV(tp);
+	struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
+	struct tcindex_filter *f = NULL;
+
+	pr_debug("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n", tp, arg, p, f);
+	if (p->perfect) {
+		if (!r->res.class)
+			return -ENOENT;
+	} else {
+		int i;
+		struct tcindex_filter **walk = NULL;
+
+		for (i = 0; i < p->hash; i++)
+			for (walk = p->h+i; *walk; walk = &(*walk)->next)
+				if (&(*walk)->result == r)
+					goto found;
+		return -ENOENT;
+
+found:
+		f = *walk;
+		if (lock)
+			tcf_tree_lock(tp);
+		*walk = f->next;
+		if (lock)
+			tcf_tree_unlock(tp);
+	}
+	tcf_unbind_filter(tp, &r->res);
+	tcf_exts_destroy(tp, &r->exts);
+	kfree(f);
+	return 0;
+}
+
+static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
+{
+	return __tcindex_delete(tp, arg, 1);
+}
+
+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 int
+tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
+		  struct tcindex_data *p, struct tcindex_filter_result *r,
+		  struct nlattr **tb, struct nlattr *est)
+{
+	int err, balloc = 0;
+	struct tcindex_filter_result new_filter_result, *old_r = r;
+	struct tcindex_filter_result cr;
+	struct tcindex_data cp;
+	struct tcindex_filter *f = NULL; /* make gcc behave */
+	struct tcf_exts e;
+
+	err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map);
+	if (err < 0)
+		return err;
+
+	memcpy(&cp, p, sizeof(cp));
+	memset(&new_filter_result, 0, sizeof(new_filter_result));
+
+	if (old_r)
+		memcpy(&cr, r, sizeof(cr));
+	else
+		memset(&cr, 0, sizeof(cr));
+
+	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;
+	} else if (cp.h && cp.hash != cp.alloc_hash)
+		goto errout;
+
+	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;
+
+
+	err = -ENOMEM;
+	if (!cp.perfect && !cp.h) {
+		if (valid_perfect_hash(&cp)) {
+			cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
+			if (!cp.perfect)
+				goto errout;
+			balloc = 1;
+		} else {
+			cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
+			if (!cp.h)
+				goto errout;
+			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;
+	}
+
+	if (tb[TCA_TCINDEX_CLASSID]) {
+		cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
+		tcf_bind_filter(tp, &cr.res, base);
+	}
+
+	tcf_exts_change(tp, &cr.exts, &e);
+
+	tcf_tree_lock(tp);
+	if (old_r && old_r != r)
+		memset(old_r, 0, sizeof(*old_r));
+
+	memcpy(p, &cp, sizeof(cp));
+	memcpy(r, &cr, sizeof(cr));
+
+	if (r == &new_filter_result) {
+		struct tcindex_filter **fp;
+
+		f->key = handle;
+		f->result = new_filter_result;
+		f->next = NULL;
+		for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
+			/* nothing */;
+		*fp = f;
+	}
+	tcf_tree_unlock(tp);
+
+	return 0;
+
+errout_alloc:
+	if (balloc == 1)
+		kfree(cp.perfect);
+	else if (balloc == 2)
+		kfree(cp.h);
+errout:
+	tcf_exts_destroy(tp, &e);
+	return err;
+}
+
+static int
+tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
+	       struct nlattr **tca, unsigned long *arg)
+{
+	struct nlattr *opt = tca[TCA_OPTIONS];
+	struct nlattr *tb[TCA_TCINDEX_MAX + 1];
+	struct tcindex_data *p = PRIV(tp);
+	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(tp, base, handle, p, r, tb, tca[TCA_RATE]);
+}
+
+
+static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
+{
+	struct tcindex_data *p = PRIV(tp);
+	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 = p->h[i]; f; f = next) {
+			next = f->next;
+			if (walker->count >= walker->skip) {
+				if (walker->fn(tp, (unsigned long) &f->result,
+				    walker) < 0) {
+					walker->stop = 1;
+					return;
+				}
+			}
+			walker->count++;
+		}
+	}
+}
+
+
+static int tcindex_destroy_element(struct tcf_proto *tp,
+    unsigned long arg, struct tcf_walker *walker)
+{
+	return __tcindex_delete(tp, arg, 0);
+}
+
+
+static void tcindex_destroy(struct tcf_proto *tp)
+{
+	struct tcindex_data *p = PRIV(tp);
+	struct tcf_walker walker;
+
+	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);
+	kfree(p->perfect);
+	kfree(p->h);
+	kfree(p);
+	tp->root = NULL;
+}
+
+
+static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
+    struct sk_buff *skb, struct tcmsg *t)
+{
+	struct tcindex_data *p = PRIV(tp);
+	struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
+	unsigned char *b = skb_tail_pointer(skb);
+	struct nlattr *nest;
+
+	pr_debug("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
+		 tp, fh, skb, t, p, r, b);
+	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 ... */
+		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);
+		nla_nest_end(skb, nest);
+	} else {
+		if (p->perfect) {
+			t->tcm_handle = r-p->perfect;
+		} else {
+			struct tcindex_filter *f;
+			int i;
+
+			t->tcm_handle = 0;
+			for (i = 0; !t->tcm_handle && i < p->hash; i++) {
+				for (f = p->h[i]; !t->tcm_handle && f;
+				     f = f->next) {
+					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);
+
+		if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
+			goto nla_put_failure;
+		nla_nest_end(skb, nest);
+
+		if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
+			goto nla_put_failure;
+	}
+
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	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,
+	.put		=	tcindex_put,
+	.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");