cregit-Linux how code gets into the kernel

Release 4.8 net/sched/cls_tcindex.c

Directory: net/sched
/*
 * 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 rcu_head		rcu;
};


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; }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf27100.00%1100.00%
Total27100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git7258.06%133.33%
john fastabendjohn fastabend4637.10%133.33%
thomas grafthomas graf64.84%133.33%
Total124100.00%3100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12879.50%114.29%
thomas grafthomas graf2414.91%114.29%
americo wangamerico wang31.86%228.57%
stephen hemmingerstephen hemminger31.86%114.29%
john fastabendjohn fastabend21.24%114.29%
eric dumazeteric dumazet10.62%114.29%
Total161100.00%7100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
linus torvaldslinus torvalds4049.38%116.67%
pre-gitpre-git2935.80%116.67%
thomas grafthomas graf67.41%116.67%
john fastabendjohn fastabend33.70%116.67%
americo wangamerico wang22.47%116.67%
stephen hemmingerstephen hemminger11.23%116.67%
Total81100.00%6100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git6282.67%120.00%
thomas grafthomas graf79.33%120.00%
john fastabendjohn fastabend45.33%120.00%
panagiotis issaris*panagiotis issaris*11.33%120.00%
stephen hemmingerstephen hemminger11.33%120.00%
Total75100.00%5100.00%


static void tcindex_destroy_rexts(struct rcu_head *head) { struct tcindex_filter_result *r; r = container_of(head, struct tcindex_filter_result, rcu); tcf_exts_destroy(&r->exts); }

Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov3597.22%150.00%
pre-gitpre-git12.78%150.00%
Total36100.00%2100.00%


static void tcindex_destroy_fexts(struct rcu_head *head) { struct tcindex_filter *f = container_of(head, struct tcindex_filter, rcu); tcf_exts_destroy(&f->result.exts); kfree(f); }

Contributors

PersonTokensPropCommitsCommitProp
alexei starovoitovalexei starovoitov41100.00%1100.00%
Total41100.00%1100.00%


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); /* all classifiers are required to call tcf_exts_destroy() after rcu * grace period, since converted-to-rcu actions are relying on that * in cleanup() callback */ if (f) call_rcu(&f->rcu, tcindex_destroy_fexts); else call_rcu(&r->rcu, tcindex_destroy_rexts); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git14366.51%225.00%
john fastabendjohn fastabend4721.86%112.50%
alexei starovoitovalexei starovoitov188.37%112.50%
thomas grafthomas graf31.40%112.50%
americo wangamerico wang20.93%112.50%
linus torvaldslinus torvalds10.47%112.50%
stephen hemmingerstephen hemminger10.47%112.50%
Total215100.00%8100.00%


static int tcindex_destroy_element(struct tcf_proto *tp, unsigned long arg, struct tcf_walker *walker) { return tcindex_delete(tp, arg); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf2175.00%150.00%
john fastabendjohn fastabend725.00%150.00%
Total28100.00%2100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
john fastabendjohn fastabend45100.00%1100.00%
Total45100.00%1100.00%


static inline int valid_perfect_hash(struct tcindex_data *p) { return p->hash > (p->mask >> p->shift); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf2592.59%150.00%
pre-gitpre-git27.41%150.00%
Total27100.00%2100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
americo wangamerico wang36100.00%1100.00%
Total36100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
john fastabendjohn fastabend38100.00%1100.00%
Total38100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git28328.19%15.00%
thomas grafthomas graf27827.69%210.00%
john fastabendjohn fastabend22122.01%15.00%
americo wangamerico wang17016.93%1050.00%
linus torvaldslinus torvalds282.79%15.00%
patrick mchardypatrick mchardy70.70%210.00%
benjamin lahaisebenjamin lahaise70.70%15.00%
cong wangcong wang50.50%15.00%
panagiotis issaris*panagiotis issaris*50.50%15.00%
Total1004100.00%20100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
thomas grafthomas graf12773.84%19.09%
patrick mchardypatrick mchardy1810.47%327.27%
benjamin lahaisebenjamin lahaise74.07%19.09%
eric w. biedermaneric w. biederman52.91%19.09%
cong wangcong wang52.91%19.09%
pre-gitpre-git42.33%19.09%
john fastabendjohn fastabend31.74%19.09%
americo wangamerico wang21.16%19.09%
stephen hemmingerstephen hemminger10.58%19.09%
Total172100.00%11100.00%


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++; } } }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git22391.02%116.67%
linus torvaldslinus torvalds104.08%233.33%
john fastabendjohn fastabend93.67%116.67%
americo wangamerico wang20.82%116.67%
stephen hemmingerstephen hemminger10.41%116.67%
Total245100.00%6100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git6467.37%120.00%
cong wangcong wang1515.79%120.00%
john fastabendjohn fastabend1313.68%120.00%
americo wangamerico wang22.11%120.00%
stephen hemmingerstephen hemminger11.05%120.00%
Total95100.00%5100.00%


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, &