cregit-Linux how code gets into the kernel

Release 4.8 net/sched/cls_route.c

Directory: net/sched
/*
 * net/sched/cls_route.c        ROUTE4 classifier.
 *
 *              This program is free software; you can redistribute it and/or
 *              modify it under the terms of the GNU General Public License
 *              as published by the Free Software Foundation; either version
 *              2 of the License, or (at your option) any later version.
 *
 * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/dst.h>
#include <net/route.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>

/*
 * 1. For now we assume that route tags < 256.
 *    It allows to use direct table lookups, instead of hash tables.
 * 2. For now we assume that "from TAG" and "fromdev DEV" statements
 *    are mutually  exclusive.
 * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
 */

struct route4_fastmap {
	
struct route4_filter		*filter;
	
u32				id;
	
int				iif;
};


struct route4_head {
	
struct route4_fastmap		fastmap[16];
	
struct route4_bucket __rcu	*table[256 + 1];
	
struct rcu_head			rcu;
};


struct route4_bucket {
	/* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
	
struct route4_filter __rcu	*ht[16 + 16 + 1];
	
struct rcu_head			rcu;
};


struct route4_filter {
	
struct route4_filter __rcu	*next;
	
u32			id;
	
int			iif;

	
struct tcf_result	res;
	
struct tcf_exts		exts;
	
u32			handle;
	
struct route4_bucket	*bkt;
	
struct tcf_proto	*tp;
	
struct rcu_head		rcu;
};


#define ROUTE4_FAILURE ((struct route4_filter *)(-1L))


static inline int route4_fastmap_hash(u32 id, int iif) { return id & 0xF; }

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static DEFINE_SPINLOCK(fastmap_lock);
static void route4_reset_fastmap(struct route4_head *head) { spin_lock_bh(&fastmap_lock); memset(head->fastmap, 0, sizeof(head->fastmap)); spin_unlock_bh(&fastmap_lock); }

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Total39100.00%5100.00%


static void route4_set_fastmap(struct route4_head *head, u32 id, int iif, struct route4_filter *f) { int h = route4_fastmap_hash(id, iif); /* fastmap updates must look atomic to aling id, iff, filter */ spin_lock_bh(&fastmap_lock); head->fastmap[h].id = id; head->fastmap[h].iif = iif; head->fastmap[h].filter = f; spin_unlock_bh(&fastmap_lock); }

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static inline int route4_hash_to(u32 id) { return id & 0xFF; }

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static inline int route4_hash_from(u32 id) { return (id >> 16) & 0xF; }

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static inline int route4_hash_iif(int iif) { return 16 + ((iif >> 16) & 0xF); }

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static inline int route4_hash_wild(void) { return 32; }

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#define ROUTE4_APPLY_RESULT() \ { \ *res = f->res; \ if (tcf_exts_is_available(&f->exts)) { \ int r = tcf_exts_exec(skb, &f->exts, res); \ if (r < 0) { \ dont_cache = 1; \ continue; \ } \ return r; \ } else if (!dont_cache) \ route4_set_fastmap(head, id, iif, f); \ return 0; \ }
static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res) { struct route4_head *head = rcu_dereference_bh(tp->root); struct dst_entry *dst; struct route4_bucket *b; struct route4_filter *f; u32 id, h; int iif, dont_cache = 0; dst = skb_dst(skb); if (!dst) goto failure; id = dst->tclassid; if (head == NULL) goto old_method; iif = inet_iif(skb); h = route4_fastmap_hash(id, iif); spin_lock(&fastmap_lock); if (id == head->fastmap[h].id && iif == head->fastmap[h].iif && (f = head->fastmap[h].filter) != NULL) { if (f == ROUTE4_FAILURE) { spin_unlock(&fastmap_lock); goto failure; } *res = f->res; spin_unlock(&fastmap_lock); return 0; } spin_unlock(&fastmap_lock); h = route4_hash_to(id); restart: b = rcu_dereference_bh(head->table[h]); if (b) { for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]); f; f = rcu_dereference_bh(f->next)) if (f->id == id) ROUTE4_APPLY_RESULT(); for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]); f; f = rcu_dereference_bh(f->next)) if (f->iif == iif) ROUTE4_APPLY_RESULT(); for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]); f; f = rcu_dereference_bh(f->next)) ROUTE4_APPLY_RESULT(); } if (h < 256) { h = 256; id &= ~0xFFFF; goto restart; } if (!dont_cache) route4_set_fastmap(head, id, iif, ROUTE4_FAILURE); failure: return -1; old_method: if (id && (TC_H_MAJ(id) == 0 || !(TC_H_MAJ(id^tp->q->handle)))) { res->classid = id; res->class = 0; return 0; } return -1; }

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eric dumazeteric dumazet133.10%337.50%
thomas grafthomas graf122.86%112.50%
david s. millerdavid s. miller40.95%112.50%
Total419100.00%8100.00%


static inline u32 to_hash(u32 id) { u32 h = id & 0xFF; if (id & 0x8000) h += 256; return h; }

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static inline u32 from_hash(u32 id) { id &= 0xFFFF; if (id == 0xFFFF) return 32; if (!(id & 0x8000)) { if (id > 255) return 256; return id & 0xF; } return 16 + (id & 0xF); }

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static unsigned long route4_get(struct tcf_proto *tp, u32 handle) { struct route4_head *head = rtnl_dereference(tp->root); struct route4_bucket *b; struct route4_filter *f; unsigned int h1, h2; if (!head) return 0; h1 = to_hash(handle); if (h1 > 256) return 0; h2 = from_hash(handle >> 16); if (h2 > 32) return 0; b = rtnl_dereference(head->table[h1]); if (b) { for (f = rtnl_dereference(b->ht[h2]); f; f = rtnl_dereference(f->next)) if (f->handle == handle) return (unsigned long)f; } return 0; }

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Total146100.00%3100.00%


static int route4_init(struct tcf_proto *tp) { struct route4_head *head; head = kzalloc(sizeof(struct route4_head), GFP_KERNEL); if (head == NULL) return -ENOBUFS; rcu_assign_pointer(tp->root, head); return 0; }

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static void route4_delete_filter(struct rcu_head *head) { struct route4_filter *f = container_of(head, struct route4_filter, rcu); tcf_exts_destroy(&f->exts); kfree(f); }

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static bool route4_destroy(struct tcf_proto *tp, bool force) { struct route4_head *head = rtnl_dereference(tp->root); int h1, h2; if (head == NULL) return true; if (!force) { for (h1 = 0; h1 <= 256; h1++) { if (rcu_access_pointer(head->table[h1])) return false; } } for (h1 = 0; h1 <= 256; h1++) { struct route4_bucket *b; b = rtnl_dereference(head->table[h1]); if (b) { for (h2 = 0; h2 <= 32; h2++) { struct route4_filter *f; while ((f = rtnl_dereference(b->ht[h2])) != NULL) { struct route4_filter *next; next = rtnl_dereference(f->next); RCU_INIT_POINTER(b->ht[h2], next); tcf_unbind_filter(tp, &f->res); call_rcu(&f->rcu, route4_delete_filter); } } RCU_INIT_POINTER(head->table[h1], NULL); kfree_rcu(b, rcu); } } RCU_INIT_POINTER(tp->root, NULL); kfree_rcu(head, rcu); return true; }

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eric dumazeteric dumazet41.67%120.00%
Total239100.00%5100.00%


static int route4_delete(struct tcf_proto *tp, unsigned long arg) { struct route4_head *head = rtnl_dereference(tp->root); struct route4_filter *f = (struct route4_filter *)arg; struct route4_filter __rcu **fp; struct route4_filter *nf; struct route4_bucket *b; unsigned int h = 0; int i; if (!head || !f) return -EINVAL; h = f->handle; b = f->bkt; fp = &b->ht[from_hash(h >> 16)]; for (nf = rtnl_dereference(*fp); nf; fp = &nf->next, nf = rtnl_dereference(*fp)) { if (nf == f) { /* unlink it */ RCU_INIT_POINTER(*fp, rtnl_dereference(f->next)); /* Remove any fastmap lookups that might ref filter * notice we unlink'd the filter so we can't get it * back in the fastmap. */ route4_reset_fastmap(head); /* Delete it */ tcf_unbind_filter(tp, &f->res); call_rcu(&f->rcu, route4_delete_filter); /* Strip RTNL protected tree */ for (i = 0; i <= 32; i++) { struct route4_filter *rt; rt = rtnl_dereference(b->ht[i]); if (rt) return 0; } /* OK, session has no flows */ RCU_INIT_POINTER(head->table[to_hash(h)], NULL); kfree_rcu(b, rcu); return 0; } } return 0; }

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Total251100.00%5100.00%

static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = { [TCA_ROUTE4_CLASSID] = { .type = NLA_U32 }, [TCA_ROUTE4_TO] = { .type = NLA_U32 }, [TCA_ROUTE4_FROM] = { .type = NLA_U32 }, [TCA_ROUTE4_IIF] = { .type = NLA_U32 }, };
static int route4_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base, struct route4_filter *f, u32 handle, struct route4_head *head, struct nlattr **tb, struct nlattr *est, int new, bool ovr) { int err; u32 id = 0, to = 0, nhandle = 0x8000; struct route4_filter *fp; unsigned int h1; struct route4_bucket *b; struct tcf_exts e; tcf_exts_init(&e, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE); err = tcf_exts_validate(net, tp, tb, est, &e, ovr); if (err < 0) return err; err = -EINVAL; if (tb[TCA_ROUTE4_TO]) { if (new && handle & 0x8000) goto errout; to = nla_get_u32(tb[TCA_ROUTE4_TO]); if (to > 0xFF) goto errout; nhandle = to; } if (tb[TCA_ROUTE4_FROM]) { if (tb[TCA_ROUTE4_IIF]) goto errout; id = nla_get_u32(tb[TCA_ROUTE4_FROM]); if (id > 0xFF) goto errout; nhandle |= id << 16; } else if (tb[TCA_ROUTE4_IIF]) { id = nla_get_u32(tb[TCA_ROUTE4_IIF]); if (id > 0x7FFF) goto errout; nhandle |= (id | 0x8000) << 16; } else nhandle |= 0xFFFF << 16; if (handle && new) { nhandle |= handle & 0x7F00; if (nhandle != handle) goto errout; } h1 = to_hash(nhandle); b = rtnl_dereference(head->table[h1]); if (!b) { err = -ENOBUFS; b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL); if (b == NULL) goto errout; rcu_assign_pointer(head->table[h1], b); } else { unsigned int h2 = from_hash(nhandle >> 16); err = -EEXIST; for (fp = rtnl_dereference(b->ht[h2]); fp; fp = rtnl_dereference(fp->next)) if (fp->handle == f->handle) goto errout; } if (tb[TCA_ROUTE4_TO]) f->id = to; if (tb[TCA_ROUTE4_FROM]) f->id = to | id<<16; else if (tb[TCA_ROUTE4_IIF]) f->iif = id; f->handle = nhandle; f->bkt = b; f->tp = tp; if (tb[TCA_ROUTE4_CLASSID]) { f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]); tcf_bind_filter(tp, &f->res, base); } tcf_exts_change(tp, &f->exts, &e); return 0; errout: tcf_exts_destroy(&e); return err; }

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john fastabendjohn fastabend152.84%17.69%
americo wangamerico wang101.89%17.69%
patrick mchardypatrick mchardy81.52%323.08%
benjamin lahaisebenjamin lahaise71.33%17.69%
cong wangcong wang50.95%17.69%
eric dumazeteric dumazet50.95%17.69%
panagiotis issaris*panagiotis issaris*10.19%17.69%
Total528100.00%13100.00%


static int route4_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 route4_head *head = rtnl_dereference(tp->root); struct route4_filter __rcu **fp; struct route4_filter *fold, *f1, *pfp, *f = NULL; struct route4_bucket *b; struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_ROUTE4_MAX + 1]; unsigned int h, th; int err; bool new = true; if (opt == NULL) return handle ? -EINVAL : 0; err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy); if (err < 0) return err; fold = (struct route4_filter *)*arg; if (fold && handle && fold->handle != handle) return -EINVAL; err = -ENOBUFS; f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL); if (!f) goto errout; tcf_exts_init(&f->exts, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE); if (fold) { f->id = fold->id; f->iif = fold->iif; f->res = fold->res; f->handle = fold->handle; f->tp = fold->tp; f->bkt = fold->bkt; new = false; } err = route4_set_parms(net, tp, base, f, handle, head, tb, tca[TCA_RATE], new, ovr); if (err < 0) goto errout; h = from_hash(f->handle >> 16); fp = &f->bkt->ht[h]; for (pfp = rtnl_dereference(*fp); (f1 = rtnl_dereference(*fp)) != NULL; fp = &f1->next) if (f->handle < f1->handle) break; netif_keep_dst(qdisc_dev(tp->q)); rcu_assign_pointer(f->next, f1); rcu_assign_pointer(*fp, f); if (fold && fold->handle && f->handle != fold->handle) { th = to_hash(fold->handle); h = from_hash(fold->handle >> 16); b = rtnl_dereference(head->table[th]); if (b) { fp = &b->ht[h]; for (pfp = rtnl_dereference(*fp); pfp; fp = &pfp->next, pfp = rtnl_dereference(*fp)) { if (pfp == f) { *fp = f->next; break; } } } } route4_reset_fastmap(head); *arg = (unsigned long)f; if (fold) { tcf_unbind_filter(tp, &fold->res); call_rcu(&fold->rcu, route4_delete_filter); } return 0; errout: kfree(f); return err; }

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thomas grafthomas graf22139.12%212.50%
john fastabendjohn fastabend17030.09%212.50%
pre-gitpre-git11219.82%16.25%
eric dumazeteric dumazet173.01%212.50%
patrick mchardypatrick mchardy152.65%318.75%
americo wangamerico wang122.12%212.50%
benjamin lahaisebenjamin lahaise71.24%16.25%
cong wangcong wang50.88%16.25%
eric w. biedermaneric w. biederman50.88%16.25%
panagiotis issaris*panagiotis issaris*10.18%16.25%
Total565100.00%16100.00%


static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg) { struct route4_head *head = rtnl_dereference(tp->root); unsigned int h, h1; if (head == NULL) arg->stop = 1; if (arg->stop) return; for (h = 0; h <= 256; h++) { struct route4_bucket *b = rtnl_dereference(head->table[h]); if (b) { for (h1 = 0; h1 <= 32; h1++) { struct route4_filter *f; for (f = rtnl_dereference(b->ht[h1]); f; f = rtnl_dereference(f->next)) { if (arg->count < arg->skip) { arg->count++; continue; } if (arg->fn(tp, (unsigned long)f, arg) < 0) { arg->stop = 1; return; } arg->count++; } } } } }

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john fastabendjohn fastabend126.42%125.00%
eric dumazeteric dumazet10.53%125.00%
thomas grafthomas graf10.53%125.00%
Total187100.00%4100.00%


static int route4_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, struct sk_buff *skb, struct tcmsg *t) { struct route4_filter *f = (struct route4_filter *)fh; struct nlattr *nest; u32 id; if (f == NULL) return skb->len; t->tcm_handle = f->handle; nest = nla_nest_start(skb, TCA_OPTIONS); if (nest == NULL) goto nla_put_failure; if (!(f->handle & 0x8000