diff options
Diffstat (limited to 'net/sched/cls_tcindex.c')
| -rw-r--r-- | net/sched/cls_tcindex.c | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c new file mode 100644 index 00000000000..404d9d83a7f --- /dev/null +++ b/net/sched/cls_tcindex.c @@ -0,0 +1,537 @@ +/* + * net/sched/cls_tcindex.c Packet classifier for skb->tc_index + * + * Written 1998,1999 by Werner Almesberger, EPFL ICA + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/errno.h> +#include <linux/netdevice.h> +#include <net/ip.h> +#include <net/act_api.h> +#include <net/pkt_cls.h> +#include <net/route.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 */ + + +#if 1 /* control */ +#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) +#else +#define DPRINTK(format,args...) +#endif + +#if 0 /* data */ +#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args) +#else +#define D2PRINTK(format,args...) +#endif + + +#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 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; + + D2PRINTK("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; + D2PRINTK("alg 0x%x\n",res->classid); + return 0; + } + *res = f->res; + D2PRINTK("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; + + DPRINTK("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) +{ + DPRINTK("tcindex_put(tp %p,f 0x%lx)\n",tp,f); +} + + +static int tcindex_init(struct tcf_proto *tp) +{ + struct tcindex_data *p; + + DPRINTK("tcindex_init(tp %p)\n",tp); + p = kmalloc(sizeof(struct tcindex_data),GFP_KERNEL); + if (!p) + return -ENOMEM; + + memset(p, 0, sizeof(*p)); + 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; + + DPRINTK("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); + if (f) + 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 int +tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle, + struct tcindex_data *p, struct tcindex_filter_result *r, + struct rtattr **tb, struct rtattr *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)); + + err = -EINVAL; + if (tb[TCA_TCINDEX_HASH-1]) { + if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(u32)) + goto errout; + cp.hash = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]); + } + + if (tb[TCA_TCINDEX_MASK-1]) { + if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(u16)) + goto errout; + cp.mask = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]); + } + + if (tb[TCA_TCINDEX_SHIFT-1]) { + if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(u16)) + goto errout; + cp.shift = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]); + } + + 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-1]) { + if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(u32)) + goto errout; + cp.fall_through = + *(u32 *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]); + } + + 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 = kmalloc(cp.hash * sizeof(*r), GFP_KERNEL); + if (!cp.perfect) + goto errout; + memset(cp.perfect, 0, cp.hash * sizeof(*r)); + balloc = 1; + } else { + cp.h = kmalloc(cp.hash * sizeof(f), GFP_KERNEL); + if (!cp.h) + goto errout; + memset(cp.h, 0, cp.hash * sizeof(f)); + balloc = 2; + } + } + + if (cp.perfect) + r = cp.perfect + handle; + else + r = tcindex_lookup(&cp, handle) ? : &new_filter_result; + + if (r == &new_filter_result) { + f = kmalloc(sizeof(*f), GFP_KERNEL); + if (!f) + goto errout_alloc; + memset(f, 0, sizeof(*f)); + } + + if (tb[TCA_TCINDEX_CLASSID-1]) { + cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]); + 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 rtattr **tca, unsigned long *arg) +{ + struct rtattr *opt = tca[TCA_OPTIONS-1]; + struct rtattr *tb[TCA_TCINDEX_MAX]; + struct tcindex_data *p = PRIV(tp); + struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg; + + DPRINTK("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; + + if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0) + return -EINVAL; + + return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]); +} + + +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; + + DPRINTK("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; + + DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p); + walker.count = 0; + walker.skip = 0; + walker.fn = &tcindex_destroy_element; + tcindex_walk(tp,&walker); + if (p->perfect) + kfree(p->perfect); + if (p->h) + 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; + struct rtattr *rta; + + DPRINTK("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); + DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h); + rta = (struct rtattr *) b; + RTA_PUT(skb,TCA_OPTIONS,0,NULL); + if (!fh) { + t->tcm_handle = ~0; /* whatever ... */ + RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash); + RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask); + RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift); + RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through), + &p->fall_through); + rta->rta_len = skb->tail-b; + } 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; + } + } + } + DPRINTK("handle = %d\n",t->tcm_handle); + if (r->res.class) + RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid); + + if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0) + goto rtattr_failure; + rta->rta_len = skb->tail-b; + + if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0) + goto rtattr_failure; + } + + return skb->len; + +rtattr_failure: + skb_trim(skb, b - skb->data); + return -1; +} + +static struct tcf_proto_ops cls_tcindex_ops = { + .next = NULL, + .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"); |