- 根目录:
- net
- sched
- cls_flow.c
/*
* net/sched/cls_flow.c Generic flow classifier
*
* Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/pkt_cls.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_vlan.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <net/pkt_cls.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/flow_keys.h>
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#include <net/netfilter/nf_conntrack.h>
#endif
struct flow_head {
struct list_head filters;
};
struct flow_filter {
struct list_head list;
struct tcf_exts exts;
struct tcf_ematch_tree ematches;
struct timer_list perturb_timer;
u32 perturb_period;
u32 handle;
u32 nkeys;
u32 keymask;
u32 mode;
u32 mask;
u32 xor;
u32 rshift;
u32 addend;
u32 divisor;
u32 baseclass;
u32 hashrnd;
};
static const struct tcf_ext_map flow_ext_map = {
.action = TCA_FLOW_ACT,
.police = TCA_FLOW_POLICE,
};
static inline u32 addr_fold(void *addr)
{
unsigned long a = (unsigned long)addr;
return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
}
static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
if (flow->src)
return ntohl(flow->src);
return addr_fold(skb->sk);
}
static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
if (flow->dst)
return ntohl(flow->dst);
return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
}
static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
{
return flow->ip_proto;
}
static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
if (flow->ports)
return ntohs(flow->port16[0]);
return addr_fold(skb->sk);
}
static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
if (flow->ports)
return ntohs(flow->port16[1]);
return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
}
static u32 flow_get_iif(const struct sk_buff *skb)
{
return skb->skb_iif;
}
static u32 flow_get_priority(const struct sk_buff *skb)
{
return skb->priority;
}
static u32 flow_get_mark(const struct sk_buff *skb)
{
return skb->mark;
}
static u32 flow_get_nfct(const struct sk_buff *skb)
{
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
return addr_fold(skb->nfct);
#else
return 0;
#endif
}
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#define CTTUPLE(skb, member) \
({ \
enum ip_conntrack_info ctinfo; \
const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
if (ct == NULL) \
goto fallback; \
ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
})
#else
#define CTTUPLE(skb, member) \
({ \
goto fallback; \
0; \
})
#endif
static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
switch (skb->protocol) {
case htons(ETH_P_IP):
return ntohl(CTTUPLE(skb, src.u3.ip));
case htons(ETH_P_IPV6):
return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
}
fallback:
return flow_get_src(skb, flow);
}
static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
switch (skb->protocol) {
case htons(ETH_P_IP):
return ntohl(CTTUPLE(skb, dst.u3.ip));
case htons(ETH_P_IPV6):
return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
}
fallback:
return flow_get_dst(skb, flow);
}
static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
return ntohs(CTTUPLE(skb, src.u.all));
fallback:
return flow_get_proto_src(skb, flow);
}
static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
return ntohs(CTTUPLE(skb, dst.u.all));
fallback:
return flow_get_proto_dst(skb, flow);
}
static u32 flow_get_rtclassid(const struct sk_buff *skb)
{
#ifdef CONFIG_IP_ROUTE_CLASSID
if (skb_dst(skb))
return skb_dst(skb)->tclassid;
#endif
return 0;
}
static u32 flow_get_skuid(const struct sk_buff *skb)
{
if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
return skb->sk->sk_socket->file->f_cred->fsuid;
return 0;
}
static u32 flow_get_skgid(const struct sk_buff *skb)
{
if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
return skb->sk->sk_socket->file->f_cred->fsgid;
return 0;
}
static u32 flow_get_vlan_tag(const struct sk_buff *skb)
{
u16 uninitialized_var(tag);
if (vlan_get_tag(skb, &tag) < 0)
return 0;
return tag & VLAN_VID_MASK;
}
static u32 flow_get_rxhash(struct sk_buff *skb)
{
return skb_get_rxhash(skb);
}
static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
{
switch (key) {
case FLOW_KEY_SRC:
return flow_get_src(skb, flow);
case FLOW_KEY_DST:
return flow_get_dst(skb, flow);
case FLOW_KEY_PROTO:
return flow_get_proto(skb, flow);
case FLOW_KEY_PROTO_SRC:
return flow_get_proto_src(skb, flow);
case FLOW_KEY_PROTO_DST:
return flow_get_proto_dst(skb, flow);
case FLOW_KEY_IIF:
return flow_get_iif(skb);
case FLOW_KEY_PRIORITY:
return flow_get_priority(skb);
case FLOW_KEY_MARK:
return flow_get_mark(skb);
case FLOW_KEY_NFCT:
return flow_get_nfct(skb);
case FLOW_KEY_NFCT_SRC:
return flow_get_nfct_src(skb, flow);
case FLOW_KEY_NFCT_DST:
return flow_get_nfct_dst(skb, flow);
case FLOW_KEY_NFCT_PROTO_SRC:
return flow_get_nfct_proto_src(skb, flow);
case FLOW_KEY_NFCT_PROTO_DST:
return flow_get_nfct_proto_dst(skb, flow);
case FLOW_KEY_RTCLASSID:
return flow_get_rtclassid(skb);
case FLOW_KEY_SKUID:
return flow_get_skuid(skb);
case FLOW_KEY_SKGID:
return flow_get_skgid(skb);
case FLOW_KEY_VLAN_TAG:
return flow_get_vlan_tag(skb);
case FLOW_KEY_RXHASH:
return flow_get_rxhash(skb);
default:
WARN_ON(1);
return 0;
}
}
#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
(1 << FLOW_KEY_DST) | \
(1 << FLOW_KEY_PROTO) | \
(1 << FLOW_KEY_PROTO_SRC) | \
(1 << FLOW_KEY_PROTO_DST) | \
(1 << FLOW_KEY_NFCT_SRC) | \
(1 << FLOW_KEY_NFCT_DST) | \
(1 << FLOW_KEY_NFCT_PROTO_SRC) | \
(1 << FLOW_KEY_NFCT_PROTO_DST))
static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res)
{
struct flow_head *head = tp->root;
struct flow_filter *f;
u32 keymask;
u32 classid;
unsigned int n, key;
int r;
list_for_each_entry(f, &head->filters, list) {
u32 keys[FLOW_KEY_MAX + 1];
struct flow_keys flow_keys;
if (!tcf_em_tree_match(skb, &f->ematches, NULL))
continue;
keymask = f->keymask;
if (keymask & FLOW_KEYS_NEEDED)
skb_flow_dissect(skb, &flow_keys);
for (n = 0; n < f->nkeys; n++) {
key = ffs(keymask) - 1;
keymask &= ~(1 << key);
keys[n] = flow_key_get(skb, key, &flow_keys);
}
if (f->mode == FLOW_MODE_HASH)
classid = jhash2(keys, f->nkeys, f->hashrnd);
else {
classid = keys[0];
classid = (classid & f->mask) ^ f->xor;
classid = (classid >> f->rshift) + f->addend;
}
if (f->divisor)
classid %= f->divisor;
res->class = 0;
res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
r = tcf_exts_exec(skb, &f->exts, res);
if (r < 0)
continue;
return r;
}
return -1;
}
static void flow_perturbation(unsigned long arg)
{
struct flow_filter *f = (struct flow_filter *)arg;
get_random_bytes(&f->hashrnd, 4);
if (f->perturb_period)
mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
}
static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
[TCA_FLOW_KEYS] = { .type = NLA_U32 },
[TCA_FLOW_MODE] = { .type = NLA_U32 },
[TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
[TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
[TCA_FLOW_ADDEND] = { .type = NLA_U32 },
[TCA_FLOW_MASK] = { .type = NLA_U32 },
[TCA_FLOW_XOR] = { .type = NLA_U32 },
[TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
[TCA_FLOW_ACT] = { .type = NLA_NESTED },
[TCA_FLOW_POLICE] = { .type = NLA_NESTED },
[TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
[TCA_FLOW_PERTURB] = { .type = NLA_U32 },
};
static int flow_change(struct tcf_proto *tp, unsigned long base,
u32 handle, struct nlattr **tca,
unsigned long *arg)
{
struct flow_head *head = tp->root;
struct flow_filter *f;
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_FLOW_MAX + 1];
struct tcf_exts e;
struct tcf_ematch_tree t;
unsigned int nkeys = 0;
unsigned int perturb_period = 0;
u32 baseclass = 0;
u32 keymask = 0;
u32 mode;
int err;
if (opt == NULL)
return -EINVAL;
err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
if (err < 0)
return err;
if (tb[TCA_FLOW_BASECLASS]) {
baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
if (TC_H_MIN(baseclass) == 0)
return -EINVAL;
}
if (tb[TCA_FLOW_KEYS]) {
keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
nkeys = hweight32(keymask);
if (nkeys == 0)
return -EINVAL;
if (fls(keymask) - 1 > FLOW_KEY_MAX)
return -EOPNOTSUPP;
}
err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
if (err < 0)
return err;
err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
if (err < 0)
goto err1;
f = (struct flow_filter *)*arg;
if (f != NULL) {
err = -EINVAL;
if (f->handle != handle && handle)
goto err2;
mode = f->mode;
if (tb[TCA_FLOW_MODE])
mode = nla_get_u32(tb[TCA_FLOW_MODE]);
if (mode != FLOW_MODE_HASH && nkeys > 1)
goto err2;
if (mode == FLOW_MODE_HASH)
perturb_period = f->perturb_period;
if (tb[TCA_FLOW_PERTURB]) {
if (mode != FLOW_MODE_HASH)
goto err2;
perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
}
} else {
err = -EINVAL;
if (!handle)
goto err2;
if (!tb[TCA_FLOW_KEYS])
goto err2;
mode = FLOW_MODE_MAP;
if (tb[TCA_FLOW_MODE])
mode = nla_get_u32(tb[TCA_FLOW_MODE]);
if (mode != FLOW_MODE_HASH && nkeys > 1)
goto err2;
if (tb[TCA_FLOW_PERTURB]) {
if (mode != FLOW_MODE_HASH)
goto err2;
perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
}
if (TC_H_MAJ(baseclass) == 0)
baseclass = TC_H_MAKE(tp->q->handle, baseclass);
if (TC_H_MIN(baseclass) == 0)
baseclass = TC_H_MAKE(baseclass, 1);
err = -ENOBUFS;
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (f == NULL)
goto err2;
f->handle = handle;
f->mask = ~0U;
get_random_bytes(&f->hashrnd, 4);
f->perturb_timer.function = flow_perturbation;
f->perturb_timer.data = (unsigned long)f;
init_timer_deferrable(&f->perturb_timer);
}
tcf_exts_change(tp, &f->exts, &e);
tcf_em_tree_change(tp, &f->ematches, &t);
tcf_tree_lock(tp);
if (tb[TCA_FLOW_KEYS]) {
f->keymask = keymask;
f->nkeys = nkeys;
}
f->mode = mode;
if (tb[TCA_FLOW_MASK])
f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
if (tb[TCA_FLOW_XOR])
f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
if (tb[TCA_FLOW_RSHIFT])
f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
if (tb[TCA_FLOW_ADDEND])
f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
if (tb[TCA_FLOW_DIVISOR])
f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
if (baseclass)
f->baseclass = baseclass;
f->perturb_period = perturb_period;
del_timer(&f->perturb_timer);
if (perturb_period)
mod_timer(&f->perturb_timer, jiffies + perturb_period);
if (*arg == 0)
list_add_tail(&f->list, &head->filters);
tcf_tree_unlock(tp);
*arg = (unsigned long)f;
return 0;
err2:
tcf_em_tree_destroy(tp, &t);
err1:
tcf_exts_destroy(tp, &e);
return err;
}
static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
{
del_timer_sync(&f->perturb_timer);
tcf_exts_destroy(tp, &f->exts);
tcf_em_tree_destroy(tp, &f->ematches);
kfree(f);
}
static int flow_delete(struct tcf_proto *tp, unsigned long arg)
{
struct flow_filter *f = (struct flow_filter *)arg;
tcf_tree_lock(tp);
list_del(&f->list);
tcf_tree_unlock(tp);
flow_destroy_filter(tp, f);
return 0;
}
static int flow_init(struct tcf_proto *tp)
{
struct flow_head *head;
head = kzalloc(sizeof(*head), GFP_KERNEL);
if (head == NULL)
return -ENOBUFS;
INIT_LIST_HEAD(&head->filters);
tp->root = head;
return 0;
}
static void flow_destroy(struct tcf_proto *tp)
{
struct flow_head *head = tp->root;
struct flow_filter *f, *next;
list_for_each_entry_safe(f, next, &head->filters, list) {
list_del(&f->list);
flow_destroy_filter(tp, f);
}
kfree(head);
}
static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
{
struct flow_head *head = tp->root;
struct flow_filter *f;
list_for_each_entry(f, &head->filters, list)
if (f->handle == handle)
return (unsigned long)f;
return 0;
}
static void flow_put(struct tcf_proto *tp, unsigned long f)
{
}
static int flow_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct flow_filter *f = (struct flow_filter *)fh;
struct nlattr *nest;
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;
NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
if (f->mask != ~0 || f->xor != 0) {
NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
}
if (f->rshift)
NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
if (f->addend)
NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
if (f->divisor)
NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
if (f->baseclass)
NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
if (f->perturb_period)
NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
goto nla_put_failure;
#ifdef CONFIG_NET_EMATCH
if (f->ematches.hdr.nmatches &&
tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
goto nla_put_failure;
#endif
nla_nest_end(skb, nest);
if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, nest);
return -1;
}
static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
struct flow_head *head = tp->root;
struct flow_filter *f;
list_for_each_entry(f, &head->filters, list) {
if (arg->count < arg->skip)
goto skip;
if (arg->fn(tp, (unsigned long)f, arg) < 0) {
arg->stop = 1;
break;
}
skip:
arg->count++;
}
}
static struct tcf_proto_ops cls_flow_ops __read_mostly = {
.kind = "flow",
.classify = flow_classify,
.init = flow_init,
.destroy = flow_destroy,
.change = flow_change,
.delete = flow_delete,
.get = flow_get,
.put = flow_put,
.dump = flow_dump,
.walk = flow_walk,
.owner = THIS_MODULE,
};
static int __init cls_flow_init(void)
{
return register_tcf_proto_ops(&cls_flow_ops);
}
static void __exit cls_flow_exit(void)
{
unregister_tcf_proto_ops(&cls_flow_ops);
}
module_init(cls_flow_init);
module_exit(cls_flow_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("TC flow classifier");