|  | /* | 
|  | * 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> | 
|  |  | 
|  | /* | 
|  | * 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"); |