| /* | 
 |  * 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 */ | 
 |  | 
 |  | 
 | #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"); |