1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * net/sched/cls_flow.c Generic flow classifier
5 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/list.h>
11 #include <linux/jhash.h>
12 #include <linux/random.h>
13 #include <linux/pkt_cls.h>
14 #include <linux/skbuff.h>
17 #include <linux/ipv6.h>
18 #include <linux/if_vlan.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <net/inet_sock.h>
23 #include <net/pkt_cls.h>
25 #include <net/route.h>
26 #include <net/flow_dissector.h>
28 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
29 #include <net/netfilter/nf_conntrack.h>
33 struct list_head filters
;
38 struct list_head list
;
40 struct tcf_ematch_tree ematches
;
42 struct timer_list perturb_timer
;
56 struct rcu_work rwork
;
59 static inline u32
addr_fold(void *addr
)
61 unsigned long a
= (unsigned long)addr
;
63 return (a
& 0xFFFFFFFF) ^ (BITS_PER_LONG
> 32 ? a
>> 32 : 0);
66 static u32
flow_get_src(const struct sk_buff
*skb
, const struct flow_keys
*flow
)
68 __be32 src
= flow_get_u32_src(flow
);
73 return addr_fold(skb
->sk
);
76 static u32
flow_get_dst(const struct sk_buff
*skb
, const struct flow_keys
*flow
)
78 __be32 dst
= flow_get_u32_dst(flow
);
83 return addr_fold(skb_dst(skb
)) ^ (__force u16
)skb_protocol(skb
, true);
86 static u32
flow_get_proto(const struct sk_buff
*skb
,
87 const struct flow_keys
*flow
)
89 return flow
->basic
.ip_proto
;
92 static u32
flow_get_proto_src(const struct sk_buff
*skb
,
93 const struct flow_keys
*flow
)
95 if (flow
->ports
.ports
)
96 return ntohs(flow
->ports
.src
);
98 return addr_fold(skb
->sk
);
101 static u32
flow_get_proto_dst(const struct sk_buff
*skb
,
102 const struct flow_keys
*flow
)
104 if (flow
->ports
.ports
)
105 return ntohs(flow
->ports
.dst
);
107 return addr_fold(skb_dst(skb
)) ^ (__force u16
)skb_protocol(skb
, true);
110 static u32
flow_get_iif(const struct sk_buff
*skb
)
115 static u32
flow_get_priority(const struct sk_buff
*skb
)
117 return skb
->priority
;
120 static u32
flow_get_mark(const struct sk_buff
*skb
)
125 static u32
flow_get_nfct(const struct sk_buff
*skb
)
127 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
128 return addr_fold(skb_nfct(skb
));
134 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
135 #define CTTUPLE(skb, member) \
137 enum ip_conntrack_info ctinfo; \
138 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
141 ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
144 #define CTTUPLE(skb, member) \
151 static u32
flow_get_nfct_src(const struct sk_buff
*skb
,
152 const struct flow_keys
*flow
)
154 switch (skb_protocol(skb
, true)) {
155 case htons(ETH_P_IP
):
156 return ntohl(CTTUPLE(skb
, src
.u3
.ip
));
157 case htons(ETH_P_IPV6
):
158 return ntohl(CTTUPLE(skb
, src
.u3
.ip6
[3]));
161 return flow_get_src(skb
, flow
);
164 static u32
flow_get_nfct_dst(const struct sk_buff
*skb
,
165 const struct flow_keys
*flow
)
167 switch (skb_protocol(skb
, true)) {
168 case htons(ETH_P_IP
):
169 return ntohl(CTTUPLE(skb
, dst
.u3
.ip
));
170 case htons(ETH_P_IPV6
):
171 return ntohl(CTTUPLE(skb
, dst
.u3
.ip6
[3]));
174 return flow_get_dst(skb
, flow
);
177 static u32
flow_get_nfct_proto_src(const struct sk_buff
*skb
,
178 const struct flow_keys
*flow
)
180 return ntohs(CTTUPLE(skb
, src
.u
.all
));
182 return flow_get_proto_src(skb
, flow
);
185 static u32
flow_get_nfct_proto_dst(const struct sk_buff
*skb
,
186 const struct flow_keys
*flow
)
188 return ntohs(CTTUPLE(skb
, dst
.u
.all
));
190 return flow_get_proto_dst(skb
, flow
);
193 static u32
flow_get_rtclassid(const struct sk_buff
*skb
)
195 #ifdef CONFIG_IP_ROUTE_CLASSID
197 return skb_dst(skb
)->tclassid
;
202 static u32
flow_get_skuid(const struct sk_buff
*skb
)
204 struct sock
*sk
= skb_to_full_sk(skb
);
206 if (sk
&& sk
->sk_socket
&& sk
->sk_socket
->file
) {
207 kuid_t skuid
= sk
->sk_socket
->file
->f_cred
->fsuid
;
209 return from_kuid(&init_user_ns
, skuid
);
214 static u32
flow_get_skgid(const struct sk_buff
*skb
)
216 struct sock
*sk
= skb_to_full_sk(skb
);
218 if (sk
&& sk
->sk_socket
&& sk
->sk_socket
->file
) {
219 kgid_t skgid
= sk
->sk_socket
->file
->f_cred
->fsgid
;
221 return from_kgid(&init_user_ns
, skgid
);
226 static u32
flow_get_vlan_tag(const struct sk_buff
*skb
)
230 if (vlan_get_tag(skb
, &tag
) < 0)
232 return tag
& VLAN_VID_MASK
;
235 static u32
flow_get_rxhash(struct sk_buff
*skb
)
237 return skb_get_hash(skb
);
240 static u32
flow_key_get(struct sk_buff
*skb
, int key
, struct flow_keys
*flow
)
244 return flow_get_src(skb
, flow
);
246 return flow_get_dst(skb
, flow
);
248 return flow_get_proto(skb
, flow
);
249 case FLOW_KEY_PROTO_SRC
:
250 return flow_get_proto_src(skb
, flow
);
251 case FLOW_KEY_PROTO_DST
:
252 return flow_get_proto_dst(skb
, flow
);
254 return flow_get_iif(skb
);
255 case FLOW_KEY_PRIORITY
:
256 return flow_get_priority(skb
);
258 return flow_get_mark(skb
);
260 return flow_get_nfct(skb
);
261 case FLOW_KEY_NFCT_SRC
:
262 return flow_get_nfct_src(skb
, flow
);
263 case FLOW_KEY_NFCT_DST
:
264 return flow_get_nfct_dst(skb
, flow
);
265 case FLOW_KEY_NFCT_PROTO_SRC
:
266 return flow_get_nfct_proto_src(skb
, flow
);
267 case FLOW_KEY_NFCT_PROTO_DST
:
268 return flow_get_nfct_proto_dst(skb
, flow
);
269 case FLOW_KEY_RTCLASSID
:
270 return flow_get_rtclassid(skb
);
272 return flow_get_skuid(skb
);
274 return flow_get_skgid(skb
);
275 case FLOW_KEY_VLAN_TAG
:
276 return flow_get_vlan_tag(skb
);
277 case FLOW_KEY_RXHASH
:
278 return flow_get_rxhash(skb
);
285 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \
286 (1 << FLOW_KEY_DST) | \
287 (1 << FLOW_KEY_PROTO) | \
288 (1 << FLOW_KEY_PROTO_SRC) | \
289 (1 << FLOW_KEY_PROTO_DST) | \
290 (1 << FLOW_KEY_NFCT_SRC) | \
291 (1 << FLOW_KEY_NFCT_DST) | \
292 (1 << FLOW_KEY_NFCT_PROTO_SRC) | \
293 (1 << FLOW_KEY_NFCT_PROTO_DST))
295 static int flow_classify(struct sk_buff
*skb
, const struct tcf_proto
*tp
,
296 struct tcf_result
*res
)
298 struct flow_head
*head
= rcu_dereference_bh(tp
->root
);
299 struct flow_filter
*f
;
305 list_for_each_entry_rcu(f
, &head
->filters
, list
) {
306 u32 keys
[FLOW_KEY_MAX
+ 1];
307 struct flow_keys flow_keys
;
309 if (!tcf_em_tree_match(skb
, &f
->ematches
, NULL
))
312 keymask
= f
->keymask
;
313 if (keymask
& FLOW_KEYS_NEEDED
)
314 skb_flow_dissect_flow_keys(skb
, &flow_keys
, 0);
316 for (n
= 0; n
< f
->nkeys
; n
++) {
317 key
= ffs(keymask
) - 1;
318 keymask
&= ~(1 << key
);
319 keys
[n
] = flow_key_get(skb
, key
, &flow_keys
);
322 if (f
->mode
== FLOW_MODE_HASH
)
323 classid
= jhash2(keys
, f
->nkeys
, f
->hashrnd
);
326 classid
= (classid
& f
->mask
) ^ f
->xor;
327 classid
= (classid
>> f
->rshift
) + f
->addend
;
331 classid
%= f
->divisor
;
334 res
->classid
= TC_H_MAKE(f
->baseclass
, f
->baseclass
+ classid
);
336 r
= tcf_exts_exec(skb
, &f
->exts
, res
);
344 static void flow_perturbation(struct timer_list
*t
)
346 struct flow_filter
*f
= from_timer(f
, t
, perturb_timer
);
348 get_random_bytes(&f
->hashrnd
, 4);
349 if (f
->perturb_period
)
350 mod_timer(&f
->perturb_timer
, jiffies
+ f
->perturb_period
);
353 static const struct nla_policy flow_policy
[TCA_FLOW_MAX
+ 1] = {
354 [TCA_FLOW_KEYS
] = { .type
= NLA_U32
},
355 [TCA_FLOW_MODE
] = { .type
= NLA_U32
},
356 [TCA_FLOW_BASECLASS
] = { .type
= NLA_U32
},
357 [TCA_FLOW_RSHIFT
] = { .type
= NLA_U32
},
358 [TCA_FLOW_ADDEND
] = { .type
= NLA_U32
},
359 [TCA_FLOW_MASK
] = { .type
= NLA_U32
},
360 [TCA_FLOW_XOR
] = { .type
= NLA_U32
},
361 [TCA_FLOW_DIVISOR
] = { .type
= NLA_U32
},
362 [TCA_FLOW_ACT
] = { .type
= NLA_NESTED
},
363 [TCA_FLOW_POLICE
] = { .type
= NLA_NESTED
},
364 [TCA_FLOW_EMATCHES
] = { .type
= NLA_NESTED
},
365 [TCA_FLOW_PERTURB
] = { .type
= NLA_U32
},
368 static void __flow_destroy_filter(struct flow_filter
*f
)
370 del_timer_sync(&f
->perturb_timer
);
371 tcf_exts_destroy(&f
->exts
);
372 tcf_em_tree_destroy(&f
->ematches
);
373 tcf_exts_put_net(&f
->exts
);
377 static void flow_destroy_filter_work(struct work_struct
*work
)
379 struct flow_filter
*f
= container_of(to_rcu_work(work
),
383 __flow_destroy_filter(f
);
387 static int flow_change(struct net
*net
, struct sk_buff
*in_skb
,
388 struct tcf_proto
*tp
, unsigned long base
,
389 u32 handle
, struct nlattr
**tca
,
390 void **arg
, bool ovr
, bool rtnl_held
,
391 struct netlink_ext_ack
*extack
)
393 struct flow_head
*head
= rtnl_dereference(tp
->root
);
394 struct flow_filter
*fold
, *fnew
;
395 struct nlattr
*opt
= tca
[TCA_OPTIONS
];
396 struct nlattr
*tb
[TCA_FLOW_MAX
+ 1];
397 unsigned int nkeys
= 0;
398 unsigned int perturb_period
= 0;
407 err
= nla_parse_nested_deprecated(tb
, TCA_FLOW_MAX
, opt
, flow_policy
,
412 if (tb
[TCA_FLOW_BASECLASS
]) {
413 baseclass
= nla_get_u32(tb
[TCA_FLOW_BASECLASS
]);
414 if (TC_H_MIN(baseclass
) == 0)
418 if (tb
[TCA_FLOW_KEYS
]) {
419 keymask
= nla_get_u32(tb
[TCA_FLOW_KEYS
]);
421 nkeys
= hweight32(keymask
);
425 if (fls(keymask
) - 1 > FLOW_KEY_MAX
)
428 if ((keymask
& (FLOW_KEY_SKUID
|FLOW_KEY_SKGID
)) &&
429 sk_user_ns(NETLINK_CB(in_skb
).sk
) != &init_user_ns
)
433 fnew
= kzalloc(sizeof(*fnew
), GFP_KERNEL
);
437 err
= tcf_em_tree_validate(tp
, tb
[TCA_FLOW_EMATCHES
], &fnew
->ematches
);
441 err
= tcf_exts_init(&fnew
->exts
, net
, TCA_FLOW_ACT
, TCA_FLOW_POLICE
);
445 err
= tcf_exts_validate(net
, tp
, tb
, tca
[TCA_RATE
], &fnew
->exts
, ovr
,
453 if (fold
->handle
!= handle
&& handle
)
456 /* Copy fold into fnew */
458 fnew
->handle
= fold
->handle
;
459 fnew
->nkeys
= fold
->nkeys
;
460 fnew
->keymask
= fold
->keymask
;
461 fnew
->mode
= fold
->mode
;
462 fnew
->mask
= fold
->mask
;
463 fnew
->xor = fold
->xor;
464 fnew
->rshift
= fold
->rshift
;
465 fnew
->addend
= fold
->addend
;
466 fnew
->divisor
= fold
->divisor
;
467 fnew
->baseclass
= fold
->baseclass
;
468 fnew
->hashrnd
= fold
->hashrnd
;
471 if (tb
[TCA_FLOW_MODE
])
472 mode
= nla_get_u32(tb
[TCA_FLOW_MODE
]);
473 if (mode
!= FLOW_MODE_HASH
&& nkeys
> 1)
476 if (mode
== FLOW_MODE_HASH
)
477 perturb_period
= fold
->perturb_period
;
478 if (tb
[TCA_FLOW_PERTURB
]) {
479 if (mode
!= FLOW_MODE_HASH
)
481 perturb_period
= nla_get_u32(tb
[TCA_FLOW_PERTURB
]) * HZ
;
487 if (!tb
[TCA_FLOW_KEYS
])
490 mode
= FLOW_MODE_MAP
;
491 if (tb
[TCA_FLOW_MODE
])
492 mode
= nla_get_u32(tb
[TCA_FLOW_MODE
]);
493 if (mode
!= FLOW_MODE_HASH
&& nkeys
> 1)
496 if (tb
[TCA_FLOW_PERTURB
]) {
497 if (mode
!= FLOW_MODE_HASH
)
499 perturb_period
= nla_get_u32(tb
[TCA_FLOW_PERTURB
]) * HZ
;
502 if (TC_H_MAJ(baseclass
) == 0) {
503 struct Qdisc
*q
= tcf_block_q(tp
->chain
->block
);
505 baseclass
= TC_H_MAKE(q
->handle
, baseclass
);
507 if (TC_H_MIN(baseclass
) == 0)
508 baseclass
= TC_H_MAKE(baseclass
, 1);
510 fnew
->handle
= handle
;
513 get_random_bytes(&fnew
->hashrnd
, 4);
516 timer_setup(&fnew
->perturb_timer
, flow_perturbation
, TIMER_DEFERRABLE
);
518 tcf_block_netif_keep_dst(tp
->chain
->block
);
520 if (tb
[TCA_FLOW_KEYS
]) {
521 fnew
->keymask
= keymask
;
527 if (tb
[TCA_FLOW_MASK
])
528 fnew
->mask
= nla_get_u32(tb
[TCA_FLOW_MASK
]);
529 if (tb
[TCA_FLOW_XOR
])
530 fnew
->xor = nla_get_u32(tb
[TCA_FLOW_XOR
]);
531 if (tb
[TCA_FLOW_RSHIFT
])
532 fnew
->rshift
= nla_get_u32(tb
[TCA_FLOW_RSHIFT
]);
533 if (tb
[TCA_FLOW_ADDEND
])
534 fnew
->addend
= nla_get_u32(tb
[TCA_FLOW_ADDEND
]);
536 if (tb
[TCA_FLOW_DIVISOR
])
537 fnew
->divisor
= nla_get_u32(tb
[TCA_FLOW_DIVISOR
]);
539 fnew
->baseclass
= baseclass
;
541 fnew
->perturb_period
= perturb_period
;
543 mod_timer(&fnew
->perturb_timer
, jiffies
+ perturb_period
);
546 list_add_tail_rcu(&fnew
->list
, &head
->filters
);
548 list_replace_rcu(&fold
->list
, &fnew
->list
);
553 tcf_exts_get_net(&fold
->exts
);
554 tcf_queue_work(&fold
->rwork
, flow_destroy_filter_work
);
559 tcf_exts_destroy(&fnew
->exts
);
560 tcf_em_tree_destroy(&fnew
->ematches
);
566 static int flow_delete(struct tcf_proto
*tp
, void *arg
, bool *last
,
567 bool rtnl_held
, struct netlink_ext_ack
*extack
)
569 struct flow_head
*head
= rtnl_dereference(tp
->root
);
570 struct flow_filter
*f
= arg
;
572 list_del_rcu(&f
->list
);
573 tcf_exts_get_net(&f
->exts
);
574 tcf_queue_work(&f
->rwork
, flow_destroy_filter_work
);
575 *last
= list_empty(&head
->filters
);
579 static int flow_init(struct tcf_proto
*tp
)
581 struct flow_head
*head
;
583 head
= kzalloc(sizeof(*head
), GFP_KERNEL
);
586 INIT_LIST_HEAD(&head
->filters
);
587 rcu_assign_pointer(tp
->root
, head
);
591 static void flow_destroy(struct tcf_proto
*tp
, bool rtnl_held
,
592 struct netlink_ext_ack
*extack
)
594 struct flow_head
*head
= rtnl_dereference(tp
->root
);
595 struct flow_filter
*f
, *next
;
597 list_for_each_entry_safe(f
, next
, &head
->filters
, list
) {
598 list_del_rcu(&f
->list
);
599 if (tcf_exts_get_net(&f
->exts
))
600 tcf_queue_work(&f
->rwork
, flow_destroy_filter_work
);
602 __flow_destroy_filter(f
);
604 kfree_rcu(head
, rcu
);
607 static void *flow_get(struct tcf_proto
*tp
, u32 handle
)
609 struct flow_head
*head
= rtnl_dereference(tp
->root
);
610 struct flow_filter
*f
;
612 list_for_each_entry(f
, &head
->filters
, list
)
613 if (f
->handle
== handle
)
618 static int flow_dump(struct net
*net
, struct tcf_proto
*tp
, void *fh
,
619 struct sk_buff
*skb
, struct tcmsg
*t
, bool rtnl_held
)
621 struct flow_filter
*f
= fh
;
627 t
->tcm_handle
= f
->handle
;
629 nest
= nla_nest_start_noflag(skb
, TCA_OPTIONS
);
631 goto nla_put_failure
;
633 if (nla_put_u32(skb
, TCA_FLOW_KEYS
, f
->keymask
) ||
634 nla_put_u32(skb
, TCA_FLOW_MODE
, f
->mode
))
635 goto nla_put_failure
;
637 if (f
->mask
!= ~0 || f
->xor != 0) {
638 if (nla_put_u32(skb
, TCA_FLOW_MASK
, f
->mask
) ||
639 nla_put_u32(skb
, TCA_FLOW_XOR
, f
->xor))
640 goto nla_put_failure
;
643 nla_put_u32(skb
, TCA_FLOW_RSHIFT
, f
->rshift
))
644 goto nla_put_failure
;
646 nla_put_u32(skb
, TCA_FLOW_ADDEND
, f
->addend
))
647 goto nla_put_failure
;
650 nla_put_u32(skb
, TCA_FLOW_DIVISOR
, f
->divisor
))
651 goto nla_put_failure
;
653 nla_put_u32(skb
, TCA_FLOW_BASECLASS
, f
->baseclass
))
654 goto nla_put_failure
;
656 if (f
->perturb_period
&&
657 nla_put_u32(skb
, TCA_FLOW_PERTURB
, f
->perturb_period
/ HZ
))
658 goto nla_put_failure
;
660 if (tcf_exts_dump(skb
, &f
->exts
) < 0)
661 goto nla_put_failure
;
662 #ifdef CONFIG_NET_EMATCH
663 if (f
->ematches
.hdr
.nmatches
&&
664 tcf_em_tree_dump(skb
, &f
->ematches
, TCA_FLOW_EMATCHES
) < 0)
665 goto nla_put_failure
;
667 nla_nest_end(skb
, nest
);
669 if (tcf_exts_dump_stats(skb
, &f
->exts
) < 0)
670 goto nla_put_failure
;
675 nla_nest_cancel(skb
, nest
);
679 static void flow_walk(struct tcf_proto
*tp
, struct tcf_walker
*arg
,
682 struct flow_head
*head
= rtnl_dereference(tp
->root
);
683 struct flow_filter
*f
;
685 list_for_each_entry(f
, &head
->filters
, list
) {
686 if (arg
->count
< arg
->skip
)
688 if (arg
->fn(tp
, f
, arg
) < 0) {
697 static struct tcf_proto_ops cls_flow_ops __read_mostly
= {
699 .classify
= flow_classify
,
701 .destroy
= flow_destroy
,
702 .change
= flow_change
,
703 .delete = flow_delete
,
707 .owner
= THIS_MODULE
,
710 static int __init
cls_flow_init(void)
712 return register_tcf_proto_ops(&cls_flow_ops
);
715 static void __exit
cls_flow_exit(void)
717 unregister_tcf_proto_ops(&cls_flow_ops
);
720 module_init(cls_flow_init
);
721 module_exit(cls_flow_exit
);
723 MODULE_LICENSE("GPL");
724 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
725 MODULE_DESCRIPTION("TC flow classifier");