2 * Checksum updating actions
4 * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
13 #include <linux/types.h>
14 #include <linux/init.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/spinlock.h>
19 #include <linux/netlink.h>
20 #include <net/netlink.h>
21 #include <linux/rtnetlink.h>
23 #include <linux/skbuff.h>
28 #include <linux/icmpv6.h>
29 #include <linux/igmp.h>
32 #include <net/ip6_checksum.h>
33 #include <net/sctp/checksum.h>
35 #include <net/act_api.h>
37 #include <linux/tc_act/tc_csum.h>
38 #include <net/tc_act/tc_csum.h>
40 static const struct nla_policy csum_policy
[TCA_CSUM_MAX
+ 1] = {
41 [TCA_CSUM_PARMS
] = { .len
= sizeof(struct tc_csum
), },
44 static unsigned int csum_net_id
;
45 static struct tc_action_ops act_csum_ops
;
47 static int tcf_csum_init(struct net
*net
, struct nlattr
*nla
,
48 struct nlattr
*est
, struct tc_action
**a
, int ovr
,
51 struct tc_action_net
*tn
= net_generic(net
, csum_net_id
);
52 struct nlattr
*tb
[TCA_CSUM_MAX
+ 1];
60 err
= nla_parse_nested(tb
, TCA_CSUM_MAX
, nla
, csum_policy
, NULL
);
64 if (tb
[TCA_CSUM_PARMS
] == NULL
)
66 parm
= nla_data(tb
[TCA_CSUM_PARMS
]);
68 if (!tcf_idr_check(tn
, parm
->index
, a
, bind
)) {
69 ret
= tcf_idr_create(tn
, parm
->index
, est
, a
,
70 &act_csum_ops
, bind
, false);
75 if (bind
)/* dont override defaults */
77 tcf_idr_release(*a
, bind
);
83 spin_lock_bh(&p
->tcf_lock
);
84 p
->tcf_action
= parm
->action
;
85 p
->update_flags
= parm
->update_flags
;
86 spin_unlock_bh(&p
->tcf_lock
);
88 if (ret
== ACT_P_CREATED
)
89 tcf_idr_insert(tn
, *a
);
95 * tcf_csum_skb_nextlayer - Get next layer pointer
96 * @skb: sk_buff to use
97 * @ihl: previous summed headers length
98 * @ipl: complete packet length
99 * @jhl: next header length
101 * Check the expected next layer availability in the specified sk_buff.
102 * Return the next layer pointer if pass, NULL otherwise.
104 static void *tcf_csum_skb_nextlayer(struct sk_buff
*skb
,
105 unsigned int ihl
, unsigned int ipl
,
108 int ntkoff
= skb_network_offset(skb
);
111 if (!pskb_may_pull(skb
, ipl
+ ntkoff
) || (ipl
< hl
) ||
112 skb_try_make_writable(skb
, hl
+ ntkoff
))
115 return (void *)(skb_network_header(skb
) + ihl
);
118 static int tcf_csum_ipv4_icmp(struct sk_buff
*skb
, unsigned int ihl
,
121 struct icmphdr
*icmph
;
123 icmph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*icmph
));
128 skb
->csum
= csum_partial(icmph
, ipl
- ihl
, 0);
129 icmph
->checksum
= csum_fold(skb
->csum
);
131 skb
->ip_summed
= CHECKSUM_NONE
;
136 static int tcf_csum_ipv4_igmp(struct sk_buff
*skb
,
137 unsigned int ihl
, unsigned int ipl
)
139 struct igmphdr
*igmph
;
141 igmph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*igmph
));
146 skb
->csum
= csum_partial(igmph
, ipl
- ihl
, 0);
147 igmph
->csum
= csum_fold(skb
->csum
);
149 skb
->ip_summed
= CHECKSUM_NONE
;
154 static int tcf_csum_ipv6_icmp(struct sk_buff
*skb
, unsigned int ihl
,
157 struct icmp6hdr
*icmp6h
;
158 const struct ipv6hdr
*ip6h
;
160 icmp6h
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*icmp6h
));
164 ip6h
= ipv6_hdr(skb
);
165 icmp6h
->icmp6_cksum
= 0;
166 skb
->csum
= csum_partial(icmp6h
, ipl
- ihl
, 0);
167 icmp6h
->icmp6_cksum
= csum_ipv6_magic(&ip6h
->saddr
, &ip6h
->daddr
,
168 ipl
- ihl
, IPPROTO_ICMPV6
,
171 skb
->ip_summed
= CHECKSUM_NONE
;
176 static int tcf_csum_ipv4_tcp(struct sk_buff
*skb
, unsigned int ihl
,
180 const struct iphdr
*iph
;
182 if (skb_is_gso(skb
) && skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV4
)
185 tcph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*tcph
));
191 skb
->csum
= csum_partial(tcph
, ipl
- ihl
, 0);
192 tcph
->check
= tcp_v4_check(ipl
- ihl
,
193 iph
->saddr
, iph
->daddr
, skb
->csum
);
195 skb
->ip_summed
= CHECKSUM_NONE
;
200 static int tcf_csum_ipv6_tcp(struct sk_buff
*skb
, unsigned int ihl
,
204 const struct ipv6hdr
*ip6h
;
206 if (skb_is_gso(skb
) && skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
)
209 tcph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*tcph
));
213 ip6h
= ipv6_hdr(skb
);
215 skb
->csum
= csum_partial(tcph
, ipl
- ihl
, 0);
216 tcph
->check
= csum_ipv6_magic(&ip6h
->saddr
, &ip6h
->daddr
,
217 ipl
- ihl
, IPPROTO_TCP
,
220 skb
->ip_summed
= CHECKSUM_NONE
;
225 static int tcf_csum_ipv4_udp(struct sk_buff
*skb
, unsigned int ihl
,
226 unsigned int ipl
, int udplite
)
229 const struct iphdr
*iph
;
232 if (skb_is_gso(skb
) && skb_shinfo(skb
)->gso_type
& SKB_GSO_UDP
)
236 * Support both UDP and UDPLITE checksum algorithms, Don't use
237 * udph->len to get the real length without any protocol check,
238 * UDPLITE uses udph->len for another thing,
239 * Use iph->tot_len, or just ipl.
242 udph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*udph
));
247 ul
= ntohs(udph
->len
);
249 if (udplite
|| udph
->check
) {
255 skb
->csum
= csum_partial(udph
, ipl
- ihl
, 0);
256 else if ((ul
>= sizeof(*udph
)) && (ul
<= ipl
- ihl
))
257 skb
->csum
= csum_partial(udph
, ul
, 0);
259 goto ignore_obscure_skb
;
262 goto ignore_obscure_skb
;
264 skb
->csum
= csum_partial(udph
, ul
, 0);
267 udph
->check
= csum_tcpudp_magic(iph
->saddr
, iph
->daddr
,
272 udph
->check
= CSUM_MANGLED_0
;
275 skb
->ip_summed
= CHECKSUM_NONE
;
281 static int tcf_csum_ipv6_udp(struct sk_buff
*skb
, unsigned int ihl
,
282 unsigned int ipl
, int udplite
)
285 const struct ipv6hdr
*ip6h
;
288 if (skb_is_gso(skb
) && skb_shinfo(skb
)->gso_type
& SKB_GSO_UDP
)
292 * Support both UDP and UDPLITE checksum algorithms, Don't use
293 * udph->len to get the real length without any protocol check,
294 * UDPLITE uses udph->len for another thing,
295 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
298 udph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*udph
));
302 ip6h
= ipv6_hdr(skb
);
303 ul
= ntohs(udph
->len
);
309 skb
->csum
= csum_partial(udph
, ipl
- ihl
, 0);
311 else if ((ul
>= sizeof(*udph
)) && (ul
<= ipl
- ihl
))
312 skb
->csum
= csum_partial(udph
, ul
, 0);
315 goto ignore_obscure_skb
;
318 goto ignore_obscure_skb
;
320 skb
->csum
= csum_partial(udph
, ul
, 0);
323 udph
->check
= csum_ipv6_magic(&ip6h
->saddr
, &ip6h
->daddr
, ul
,
324 udplite
? IPPROTO_UDPLITE
: IPPROTO_UDP
,
328 udph
->check
= CSUM_MANGLED_0
;
330 skb
->ip_summed
= CHECKSUM_NONE
;
336 static int tcf_csum_sctp(struct sk_buff
*skb
, unsigned int ihl
,
339 struct sctphdr
*sctph
;
341 if (skb_is_gso(skb
) && skb_shinfo(skb
)->gso_type
& SKB_GSO_SCTP
)
344 sctph
= tcf_csum_skb_nextlayer(skb
, ihl
, ipl
, sizeof(*sctph
));
348 sctph
->checksum
= sctp_compute_cksum(skb
,
349 skb_network_offset(skb
) + ihl
);
350 skb
->ip_summed
= CHECKSUM_NONE
;
351 skb
->csum_not_inet
= 0;
356 static int tcf_csum_ipv4(struct sk_buff
*skb
, u32 update_flags
)
358 const struct iphdr
*iph
;
361 ntkoff
= skb_network_offset(skb
);
363 if (!pskb_may_pull(skb
, sizeof(*iph
) + ntkoff
))
368 switch (iph
->frag_off
& htons(IP_OFFSET
) ? 0 : iph
->protocol
) {
370 if (update_flags
& TCA_CSUM_UPDATE_FLAG_ICMP
)
371 if (!tcf_csum_ipv4_icmp(skb
, iph
->ihl
* 4,
372 ntohs(iph
->tot_len
)))
376 if (update_flags
& TCA_CSUM_UPDATE_FLAG_IGMP
)
377 if (!tcf_csum_ipv4_igmp(skb
, iph
->ihl
* 4,
378 ntohs(iph
->tot_len
)))
382 if (update_flags
& TCA_CSUM_UPDATE_FLAG_TCP
)
383 if (!tcf_csum_ipv4_tcp(skb
, iph
->ihl
* 4,
384 ntohs(iph
->tot_len
)))
388 if (update_flags
& TCA_CSUM_UPDATE_FLAG_UDP
)
389 if (!tcf_csum_ipv4_udp(skb
, iph
->ihl
* 4,
390 ntohs(iph
->tot_len
), 0))
393 case IPPROTO_UDPLITE
:
394 if (update_flags
& TCA_CSUM_UPDATE_FLAG_UDPLITE
)
395 if (!tcf_csum_ipv4_udp(skb
, iph
->ihl
* 4,
396 ntohs(iph
->tot_len
), 1))
400 if ((update_flags
& TCA_CSUM_UPDATE_FLAG_SCTP
) &&
401 !tcf_csum_sctp(skb
, iph
->ihl
* 4, ntohs(iph
->tot_len
)))
406 if (update_flags
& TCA_CSUM_UPDATE_FLAG_IPV4HDR
) {
407 if (skb_try_make_writable(skb
, sizeof(*iph
) + ntkoff
))
410 ip_send_check(ip_hdr(skb
));
419 static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr
*ip6xh
, unsigned int ixhl
,
422 int off
, len
, optlen
;
423 unsigned char *xh
= (void *)ip6xh
;
425 off
= sizeof(*ip6xh
);
434 optlen
= xh
[off
+ 1] + 2;
435 if (optlen
!= 6 || len
< 6 || (off
& 3) != 2)
436 /* wrong jumbo option length/alignment */
438 *pl
= ntohl(*(__be32
*)(xh
+ off
+ 2));
441 optlen
= xh
[off
+ 1] + 2;
443 /* ignore obscure options */
455 static int tcf_csum_ipv6(struct sk_buff
*skb
, u32 update_flags
)
457 struct ipv6hdr
*ip6h
;
458 struct ipv6_opt_hdr
*ip6xh
;
459 unsigned int hl
, ixhl
;
464 ntkoff
= skb_network_offset(skb
);
468 if (!pskb_may_pull(skb
, hl
+ ntkoff
))
471 ip6h
= ipv6_hdr(skb
);
473 pl
= ntohs(ip6h
->payload_len
);
474 nexthdr
= ip6h
->nexthdr
;
478 case NEXTHDR_FRAGMENT
:
480 case NEXTHDR_ROUTING
:
483 if (!pskb_may_pull(skb
, hl
+ sizeof(*ip6xh
) + ntkoff
))
485 ip6xh
= (void *)(skb_network_header(skb
) + hl
);
486 ixhl
= ipv6_optlen(ip6xh
);
487 if (!pskb_may_pull(skb
, hl
+ ixhl
+ ntkoff
))
489 ip6xh
= (void *)(skb_network_header(skb
) + hl
);
490 if ((nexthdr
== NEXTHDR_HOP
) &&
491 !(tcf_csum_ipv6_hopopts(ip6xh
, ixhl
, &pl
)))
493 nexthdr
= ip6xh
->nexthdr
;
497 if (update_flags
& TCA_CSUM_UPDATE_FLAG_ICMP
)
498 if (!tcf_csum_ipv6_icmp(skb
,
499 hl
, pl
+ sizeof(*ip6h
)))
503 if (update_flags
& TCA_CSUM_UPDATE_FLAG_TCP
)
504 if (!tcf_csum_ipv6_tcp(skb
,
505 hl
, pl
+ sizeof(*ip6h
)))
509 if (update_flags
& TCA_CSUM_UPDATE_FLAG_UDP
)
510 if (!tcf_csum_ipv6_udp(skb
, hl
,
511 pl
+ sizeof(*ip6h
), 0))
514 case IPPROTO_UDPLITE
:
515 if (update_flags
& TCA_CSUM_UPDATE_FLAG_UDPLITE
)
516 if (!tcf_csum_ipv6_udp(skb
, hl
,
517 pl
+ sizeof(*ip6h
), 1))
521 if ((update_flags
& TCA_CSUM_UPDATE_FLAG_SCTP
) &&
522 !tcf_csum_sctp(skb
, hl
, pl
+ sizeof(*ip6h
)))
528 } while (pskb_may_pull(skb
, hl
+ 1 + ntkoff
));
538 static int tcf_csum(struct sk_buff
*skb
, const struct tc_action
*a
,
539 struct tcf_result
*res
)
541 struct tcf_csum
*p
= to_tcf_csum(a
);
545 spin_lock(&p
->tcf_lock
);
546 tcf_lastuse_update(&p
->tcf_tm
);
547 bstats_update(&p
->tcf_bstats
, skb
);
548 action
= p
->tcf_action
;
549 update_flags
= p
->update_flags
;
550 spin_unlock(&p
->tcf_lock
);
552 if (unlikely(action
== TC_ACT_SHOT
))
555 switch (tc_skb_protocol(skb
)) {
556 case cpu_to_be16(ETH_P_IP
):
557 if (!tcf_csum_ipv4(skb
, update_flags
))
560 case cpu_to_be16(ETH_P_IPV6
):
561 if (!tcf_csum_ipv6(skb
, update_flags
))
569 spin_lock(&p
->tcf_lock
);
570 p
->tcf_qstats
.drops
++;
571 spin_unlock(&p
->tcf_lock
);
575 static int tcf_csum_dump(struct sk_buff
*skb
, struct tc_action
*a
, int bind
,
578 unsigned char *b
= skb_tail_pointer(skb
);
579 struct tcf_csum
*p
= to_tcf_csum(a
);
580 struct tc_csum opt
= {
581 .update_flags
= p
->update_flags
,
582 .index
= p
->tcf_index
,
583 .action
= p
->tcf_action
,
584 .refcnt
= p
->tcf_refcnt
- ref
,
585 .bindcnt
= p
->tcf_bindcnt
- bind
,
589 if (nla_put(skb
, TCA_CSUM_PARMS
, sizeof(opt
), &opt
))
590 goto nla_put_failure
;
592 tcf_tm_dump(&t
, &p
->tcf_tm
);
593 if (nla_put_64bit(skb
, TCA_CSUM_TM
, sizeof(t
), &t
, TCA_CSUM_PAD
))
594 goto nla_put_failure
;
603 static int tcf_csum_walker(struct net
*net
, struct sk_buff
*skb
,
604 struct netlink_callback
*cb
, int type
,
605 const struct tc_action_ops
*ops
)
607 struct tc_action_net
*tn
= net_generic(net
, csum_net_id
);
609 return tcf_generic_walker(tn
, skb
, cb
, type
, ops
);
612 static int tcf_csum_search(struct net
*net
, struct tc_action
**a
, u32 index
)
614 struct tc_action_net
*tn
= net_generic(net
, csum_net_id
);
616 return tcf_idr_search(tn
, a
, index
);
619 static struct tc_action_ops act_csum_ops
= {
621 .type
= TCA_ACT_CSUM
,
622 .owner
= THIS_MODULE
,
624 .dump
= tcf_csum_dump
,
625 .init
= tcf_csum_init
,
626 .walk
= tcf_csum_walker
,
627 .lookup
= tcf_csum_search
,
628 .size
= sizeof(struct tcf_csum
),
631 static __net_init
int csum_init_net(struct net
*net
)
633 struct tc_action_net
*tn
= net_generic(net
, csum_net_id
);
635 return tc_action_net_init(net
, tn
, &act_csum_ops
);
638 static void __net_exit
csum_exit_net(struct net
*net
)
640 struct tc_action_net
*tn
= net_generic(net
, csum_net_id
);
642 tc_action_net_exit(tn
);
645 static struct pernet_operations csum_net_ops
= {
646 .init
= csum_init_net
,
647 .exit
= csum_exit_net
,
649 .size
= sizeof(struct tc_action_net
),
652 MODULE_DESCRIPTION("Checksum updating actions");
653 MODULE_LICENSE("GPL");
655 static int __init
csum_init_module(void)
657 return tcf_register_action(&act_csum_ops
, &csum_net_ops
);
660 static void __exit
csum_cleanup_module(void)
662 tcf_unregister_action(&act_csum_ops
, &csum_net_ops
);
665 module_init(csum_init_module
);
666 module_exit(csum_cleanup_module
);