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torvalds
GitHub Repository: torvalds/linux
Path: blob/master/net/core/flow_dissector.c
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1
// SPDX-License-Identifier: GPL-2.0-only
2
#include <linux/kernel.h>
3
#include <linux/skbuff.h>
4
#include <linux/export.h>
5
#include <linux/ip.h>
6
#include <linux/ipv6.h>
7
#include <linux/if_vlan.h>
8
#include <linux/filter.h>
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#include <net/dsa.h>
10
#include <net/dst_metadata.h>
11
#include <net/ip.h>
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#include <net/ipv6.h>
13
#include <net/gre.h>
14
#include <net/pptp.h>
15
#include <net/tipc.h>
16
#include <linux/igmp.h>
17
#include <linux/icmp.h>
18
#include <linux/sctp.h>
19
#include <linux/dccp.h>
20
#include <linux/if_tunnel.h>
21
#include <linux/if_pppox.h>
22
#include <linux/ppp_defs.h>
23
#include <linux/stddef.h>
24
#include <linux/if_ether.h>
25
#include <linux/if_hsr.h>
26
#include <linux/mpls.h>
27
#include <linux/tcp.h>
28
#include <linux/ptp_classify.h>
29
#include <net/flow_dissector.h>
30
#include <net/pkt_cls.h>
31
#include <scsi/fc/fc_fcoe.h>
32
#include <uapi/linux/batadv_packet.h>
33
#include <linux/bpf.h>
34
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
35
#include <net/netfilter/nf_conntrack_core.h>
36
#include <net/netfilter/nf_conntrack_labels.h>
37
#endif
38
#include <linux/bpf-netns.h>
39
40
static void dissector_set_key(struct flow_dissector *flow_dissector,
41
enum flow_dissector_key_id key_id)
42
{
43
flow_dissector->used_keys |= (1ULL << key_id);
44
}
45
46
void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
47
const struct flow_dissector_key *key,
48
unsigned int key_count)
49
{
50
unsigned int i;
51
52
memset(flow_dissector, 0, sizeof(*flow_dissector));
53
54
for (i = 0; i < key_count; i++, key++) {
55
/* User should make sure that every key target offset is within
56
* boundaries of unsigned short.
57
*/
58
BUG_ON(key->offset > USHRT_MAX);
59
BUG_ON(dissector_uses_key(flow_dissector,
60
key->key_id));
61
62
dissector_set_key(flow_dissector, key->key_id);
63
flow_dissector->offset[key->key_id] = key->offset;
64
}
65
66
/* Ensure that the dissector always includes control and basic key.
67
* That way we are able to avoid handling lack of these in fast path.
68
*/
69
BUG_ON(!dissector_uses_key(flow_dissector,
70
FLOW_DISSECTOR_KEY_CONTROL));
71
BUG_ON(!dissector_uses_key(flow_dissector,
72
FLOW_DISSECTOR_KEY_BASIC));
73
}
74
EXPORT_SYMBOL(skb_flow_dissector_init);
75
76
#ifdef CONFIG_BPF_SYSCALL
77
int flow_dissector_bpf_prog_attach_check(struct net *net,
78
struct bpf_prog *prog)
79
{
80
enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
81
82
if (net == &init_net) {
83
/* BPF flow dissector in the root namespace overrides
84
* any per-net-namespace one. When attaching to root,
85
* make sure we don't have any BPF program attached
86
* to the non-root namespaces.
87
*/
88
struct net *ns;
89
90
for_each_net(ns) {
91
if (ns == &init_net)
92
continue;
93
if (rcu_access_pointer(ns->bpf.run_array[type]))
94
return -EEXIST;
95
}
96
} else {
97
/* Make sure root flow dissector is not attached
98
* when attaching to the non-root namespace.
99
*/
100
if (rcu_access_pointer(init_net.bpf.run_array[type]))
101
return -EEXIST;
102
}
103
104
return 0;
105
}
106
#endif /* CONFIG_BPF_SYSCALL */
107
108
/**
109
* skb_flow_get_ports - extract the upper layer ports and return them
110
* @skb: sk_buff to extract the ports from
111
* @thoff: transport header offset
112
* @ip_proto: protocol for which to get port offset
113
* @data: raw buffer pointer to the packet, if NULL use skb->data
114
* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
115
*
116
* The function will try to retrieve the ports at offset thoff + poff where poff
117
* is the protocol port offset returned from proto_ports_offset
118
*/
119
__be32 skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
120
const void *data, int hlen)
121
{
122
int poff = proto_ports_offset(ip_proto);
123
124
if (!data) {
125
data = skb->data;
126
hlen = skb_headlen(skb);
127
}
128
129
if (poff >= 0) {
130
__be32 *ports, _ports;
131
132
ports = __skb_header_pointer(skb, thoff + poff,
133
sizeof(_ports), data, hlen, &_ports);
134
if (ports)
135
return *ports;
136
}
137
138
return 0;
139
}
140
EXPORT_SYMBOL(skb_flow_get_ports);
141
142
static bool icmp_has_id(u8 type)
143
{
144
switch (type) {
145
case ICMP_ECHO:
146
case ICMP_ECHOREPLY:
147
case ICMP_TIMESTAMP:
148
case ICMP_TIMESTAMPREPLY:
149
case ICMPV6_ECHO_REQUEST:
150
case ICMPV6_ECHO_REPLY:
151
return true;
152
}
153
154
return false;
155
}
156
157
/**
158
* skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
159
* @skb: sk_buff to extract from
160
* @key_icmp: struct flow_dissector_key_icmp to fill
161
* @data: raw buffer pointer to the packet
162
* @thoff: offset to extract at
163
* @hlen: packet header length
164
*/
165
void skb_flow_get_icmp_tci(const struct sk_buff *skb,
166
struct flow_dissector_key_icmp *key_icmp,
167
const void *data, int thoff, int hlen)
168
{
169
struct icmphdr *ih, _ih;
170
171
ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
172
if (!ih)
173
return;
174
175
key_icmp->type = ih->type;
176
key_icmp->code = ih->code;
177
178
/* As we use 0 to signal that the Id field is not present,
179
* avoid confusion with packets without such field
180
*/
181
if (icmp_has_id(ih->type))
182
key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1;
183
else
184
key_icmp->id = 0;
185
}
186
EXPORT_SYMBOL(skb_flow_get_icmp_tci);
187
188
/* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
189
* using skb_flow_get_icmp_tci().
190
*/
191
static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
192
struct flow_dissector *flow_dissector,
193
void *target_container, const void *data,
194
int thoff, int hlen)
195
{
196
struct flow_dissector_key_icmp *key_icmp;
197
198
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
199
return;
200
201
key_icmp = skb_flow_dissector_target(flow_dissector,
202
FLOW_DISSECTOR_KEY_ICMP,
203
target_container);
204
205
skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
206
}
207
208
static void __skb_flow_dissect_ah(const struct sk_buff *skb,
209
struct flow_dissector *flow_dissector,
210
void *target_container, const void *data,
211
int nhoff, int hlen)
212
{
213
struct flow_dissector_key_ipsec *key_ah;
214
struct ip_auth_hdr _hdr, *hdr;
215
216
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC))
217
return;
218
219
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
220
if (!hdr)
221
return;
222
223
key_ah = skb_flow_dissector_target(flow_dissector,
224
FLOW_DISSECTOR_KEY_IPSEC,
225
target_container);
226
227
key_ah->spi = hdr->spi;
228
}
229
230
static void __skb_flow_dissect_esp(const struct sk_buff *skb,
231
struct flow_dissector *flow_dissector,
232
void *target_container, const void *data,
233
int nhoff, int hlen)
234
{
235
struct flow_dissector_key_ipsec *key_esp;
236
struct ip_esp_hdr _hdr, *hdr;
237
238
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPSEC))
239
return;
240
241
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
242
if (!hdr)
243
return;
244
245
key_esp = skb_flow_dissector_target(flow_dissector,
246
FLOW_DISSECTOR_KEY_IPSEC,
247
target_container);
248
249
key_esp->spi = hdr->spi;
250
}
251
252
static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb,
253
struct flow_dissector *flow_dissector,
254
void *target_container, const void *data,
255
int nhoff, int hlen)
256
{
257
struct flow_dissector_key_l2tpv3 *key_l2tpv3;
258
struct {
259
__be32 session_id;
260
} *hdr, _hdr;
261
262
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3))
263
return;
264
265
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
266
if (!hdr)
267
return;
268
269
key_l2tpv3 = skb_flow_dissector_target(flow_dissector,
270
FLOW_DISSECTOR_KEY_L2TPV3,
271
target_container);
272
273
key_l2tpv3->session_id = hdr->session_id;
274
}
275
276
void skb_flow_dissect_meta(const struct sk_buff *skb,
277
struct flow_dissector *flow_dissector,
278
void *target_container)
279
{
280
struct flow_dissector_key_meta *meta;
281
282
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
283
return;
284
285
meta = skb_flow_dissector_target(flow_dissector,
286
FLOW_DISSECTOR_KEY_META,
287
target_container);
288
meta->ingress_ifindex = skb->skb_iif;
289
#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
290
if (tc_skb_ext_tc_enabled()) {
291
struct tc_skb_ext *ext;
292
293
ext = skb_ext_find(skb, TC_SKB_EXT);
294
if (ext)
295
meta->l2_miss = ext->l2_miss;
296
}
297
#endif
298
}
299
EXPORT_SYMBOL(skb_flow_dissect_meta);
300
301
static void
302
skb_flow_dissect_set_enc_control(enum flow_dissector_key_id type,
303
u32 ctrl_flags,
304
struct flow_dissector *flow_dissector,
305
void *target_container)
306
{
307
struct flow_dissector_key_control *ctrl;
308
309
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
310
return;
311
312
ctrl = skb_flow_dissector_target(flow_dissector,
313
FLOW_DISSECTOR_KEY_ENC_CONTROL,
314
target_container);
315
ctrl->addr_type = type;
316
ctrl->flags = ctrl_flags;
317
}
318
319
void
320
skb_flow_dissect_ct(const struct sk_buff *skb,
321
struct flow_dissector *flow_dissector,
322
void *target_container, u16 *ctinfo_map,
323
size_t mapsize, bool post_ct, u16 zone)
324
{
325
#if IS_ENABLED(CONFIG_NF_CONNTRACK)
326
struct flow_dissector_key_ct *key;
327
enum ip_conntrack_info ctinfo;
328
struct nf_conn_labels *cl;
329
struct nf_conn *ct;
330
331
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
332
return;
333
334
ct = nf_ct_get(skb, &ctinfo);
335
if (!ct && !post_ct)
336
return;
337
338
key = skb_flow_dissector_target(flow_dissector,
339
FLOW_DISSECTOR_KEY_CT,
340
target_container);
341
342
if (!ct) {
343
key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED |
344
TCA_FLOWER_KEY_CT_FLAGS_INVALID;
345
key->ct_zone = zone;
346
return;
347
}
348
349
if (ctinfo < mapsize)
350
key->ct_state = ctinfo_map[ctinfo];
351
#if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
352
key->ct_zone = ct->zone.id;
353
#endif
354
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
355
key->ct_mark = READ_ONCE(ct->mark);
356
#endif
357
358
cl = nf_ct_labels_find(ct);
359
if (cl)
360
memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
361
#endif /* CONFIG_NF_CONNTRACK */
362
}
363
EXPORT_SYMBOL(skb_flow_dissect_ct);
364
365
void
366
skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
367
struct flow_dissector *flow_dissector,
368
void *target_container)
369
{
370
struct ip_tunnel_info *info;
371
struct ip_tunnel_key *key;
372
u32 ctrl_flags = 0;
373
374
/* A quick check to see if there might be something to do. */
375
if (!dissector_uses_key(flow_dissector,
376
FLOW_DISSECTOR_KEY_ENC_KEYID) &&
377
!dissector_uses_key(flow_dissector,
378
FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
379
!dissector_uses_key(flow_dissector,
380
FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
381
!dissector_uses_key(flow_dissector,
382
FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
383
!dissector_uses_key(flow_dissector,
384
FLOW_DISSECTOR_KEY_ENC_PORTS) &&
385
!dissector_uses_key(flow_dissector,
386
FLOW_DISSECTOR_KEY_ENC_IP) &&
387
!dissector_uses_key(flow_dissector,
388
FLOW_DISSECTOR_KEY_ENC_OPTS))
389
return;
390
391
info = skb_tunnel_info(skb);
392
if (!info)
393
return;
394
395
key = &info->key;
396
397
if (test_bit(IP_TUNNEL_CSUM_BIT, key->tun_flags))
398
ctrl_flags |= FLOW_DIS_F_TUNNEL_CSUM;
399
if (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags))
400
ctrl_flags |= FLOW_DIS_F_TUNNEL_DONT_FRAGMENT;
401
if (test_bit(IP_TUNNEL_OAM_BIT, key->tun_flags))
402
ctrl_flags |= FLOW_DIS_F_TUNNEL_OAM;
403
if (test_bit(IP_TUNNEL_CRIT_OPT_BIT, key->tun_flags))
404
ctrl_flags |= FLOW_DIS_F_TUNNEL_CRIT_OPT;
405
406
switch (ip_tunnel_info_af(info)) {
407
case AF_INET:
408
skb_flow_dissect_set_enc_control(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
409
ctrl_flags, flow_dissector,
410
target_container);
411
if (dissector_uses_key(flow_dissector,
412
FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
413
struct flow_dissector_key_ipv4_addrs *ipv4;
414
415
ipv4 = skb_flow_dissector_target(flow_dissector,
416
FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
417
target_container);
418
ipv4->src = key->u.ipv4.src;
419
ipv4->dst = key->u.ipv4.dst;
420
}
421
break;
422
case AF_INET6:
423
skb_flow_dissect_set_enc_control(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
424
ctrl_flags, flow_dissector,
425
target_container);
426
if (dissector_uses_key(flow_dissector,
427
FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
428
struct flow_dissector_key_ipv6_addrs *ipv6;
429
430
ipv6 = skb_flow_dissector_target(flow_dissector,
431
FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
432
target_container);
433
ipv6->src = key->u.ipv6.src;
434
ipv6->dst = key->u.ipv6.dst;
435
}
436
break;
437
default:
438
skb_flow_dissect_set_enc_control(0, ctrl_flags, flow_dissector,
439
target_container);
440
break;
441
}
442
443
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
444
struct flow_dissector_key_keyid *keyid;
445
446
keyid = skb_flow_dissector_target(flow_dissector,
447
FLOW_DISSECTOR_KEY_ENC_KEYID,
448
target_container);
449
keyid->keyid = tunnel_id_to_key32(key->tun_id);
450
}
451
452
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
453
struct flow_dissector_key_ports *tp;
454
455
tp = skb_flow_dissector_target(flow_dissector,
456
FLOW_DISSECTOR_KEY_ENC_PORTS,
457
target_container);
458
tp->src = key->tp_src;
459
tp->dst = key->tp_dst;
460
}
461
462
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
463
struct flow_dissector_key_ip *ip;
464
465
ip = skb_flow_dissector_target(flow_dissector,
466
FLOW_DISSECTOR_KEY_ENC_IP,
467
target_container);
468
ip->tos = key->tos;
469
ip->ttl = key->ttl;
470
}
471
472
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
473
struct flow_dissector_key_enc_opts *enc_opt;
474
IP_TUNNEL_DECLARE_FLAGS(flags) = { };
475
u32 val;
476
477
enc_opt = skb_flow_dissector_target(flow_dissector,
478
FLOW_DISSECTOR_KEY_ENC_OPTS,
479
target_container);
480
481
if (!info->options_len)
482
return;
483
484
enc_opt->len = info->options_len;
485
ip_tunnel_info_opts_get(enc_opt->data, info);
486
487
ip_tunnel_set_options_present(flags);
488
ip_tunnel_flags_and(flags, info->key.tun_flags, flags);
489
490
val = find_next_bit(flags, __IP_TUNNEL_FLAG_NUM,
491
IP_TUNNEL_GENEVE_OPT_BIT);
492
enc_opt->dst_opt_type = val < __IP_TUNNEL_FLAG_NUM ? val : 0;
493
}
494
}
495
EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
496
497
void skb_flow_dissect_hash(const struct sk_buff *skb,
498
struct flow_dissector *flow_dissector,
499
void *target_container)
500
{
501
struct flow_dissector_key_hash *key;
502
503
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
504
return;
505
506
key = skb_flow_dissector_target(flow_dissector,
507
FLOW_DISSECTOR_KEY_HASH,
508
target_container);
509
510
key->hash = skb_get_hash_raw(skb);
511
}
512
EXPORT_SYMBOL(skb_flow_dissect_hash);
513
514
static enum flow_dissect_ret
515
__skb_flow_dissect_mpls(const struct sk_buff *skb,
516
struct flow_dissector *flow_dissector,
517
void *target_container, const void *data, int nhoff,
518
int hlen, int lse_index, bool *entropy_label)
519
{
520
struct mpls_label *hdr, _hdr;
521
u32 entry, label, bos;
522
523
if (!dissector_uses_key(flow_dissector,
524
FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
525
!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
526
return FLOW_DISSECT_RET_OUT_GOOD;
527
528
if (lse_index >= FLOW_DIS_MPLS_MAX)
529
return FLOW_DISSECT_RET_OUT_GOOD;
530
531
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
532
hlen, &_hdr);
533
if (!hdr)
534
return FLOW_DISSECT_RET_OUT_BAD;
535
536
entry = ntohl(hdr->entry);
537
label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
538
bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
539
540
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
541
struct flow_dissector_key_mpls *key_mpls;
542
struct flow_dissector_mpls_lse *lse;
543
544
key_mpls = skb_flow_dissector_target(flow_dissector,
545
FLOW_DISSECTOR_KEY_MPLS,
546
target_container);
547
lse = &key_mpls->ls[lse_index];
548
549
lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
550
lse->mpls_bos = bos;
551
lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
552
lse->mpls_label = label;
553
dissector_set_mpls_lse(key_mpls, lse_index);
554
}
555
556
if (*entropy_label &&
557
dissector_uses_key(flow_dissector,
558
FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
559
struct flow_dissector_key_keyid *key_keyid;
560
561
key_keyid = skb_flow_dissector_target(flow_dissector,
562
FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
563
target_container);
564
key_keyid->keyid = cpu_to_be32(label);
565
}
566
567
*entropy_label = label == MPLS_LABEL_ENTROPY;
568
569
return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
570
}
571
572
static enum flow_dissect_ret
573
__skb_flow_dissect_arp(const struct sk_buff *skb,
574
struct flow_dissector *flow_dissector,
575
void *target_container, const void *data,
576
int nhoff, int hlen)
577
{
578
struct flow_dissector_key_arp *key_arp;
579
struct {
580
unsigned char ar_sha[ETH_ALEN];
581
unsigned char ar_sip[4];
582
unsigned char ar_tha[ETH_ALEN];
583
unsigned char ar_tip[4];
584
} *arp_eth, _arp_eth;
585
const struct arphdr *arp;
586
struct arphdr _arp;
587
588
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
589
return FLOW_DISSECT_RET_OUT_GOOD;
590
591
arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
592
hlen, &_arp);
593
if (!arp)
594
return FLOW_DISSECT_RET_OUT_BAD;
595
596
if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
597
arp->ar_pro != htons(ETH_P_IP) ||
598
arp->ar_hln != ETH_ALEN ||
599
arp->ar_pln != 4 ||
600
(arp->ar_op != htons(ARPOP_REPLY) &&
601
arp->ar_op != htons(ARPOP_REQUEST)))
602
return FLOW_DISSECT_RET_OUT_BAD;
603
604
arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
605
sizeof(_arp_eth), data,
606
hlen, &_arp_eth);
607
if (!arp_eth)
608
return FLOW_DISSECT_RET_OUT_BAD;
609
610
key_arp = skb_flow_dissector_target(flow_dissector,
611
FLOW_DISSECTOR_KEY_ARP,
612
target_container);
613
614
memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
615
memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
616
617
/* Only store the lower byte of the opcode;
618
* this covers ARPOP_REPLY and ARPOP_REQUEST.
619
*/
620
key_arp->op = ntohs(arp->ar_op) & 0xff;
621
622
ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
623
ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
624
625
return FLOW_DISSECT_RET_OUT_GOOD;
626
}
627
628
static enum flow_dissect_ret
629
__skb_flow_dissect_cfm(const struct sk_buff *skb,
630
struct flow_dissector *flow_dissector,
631
void *target_container, const void *data,
632
int nhoff, int hlen)
633
{
634
struct flow_dissector_key_cfm *key, *hdr, _hdr;
635
636
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CFM))
637
return FLOW_DISSECT_RET_OUT_GOOD;
638
639
hdr = __skb_header_pointer(skb, nhoff, sizeof(*key), data, hlen, &_hdr);
640
if (!hdr)
641
return FLOW_DISSECT_RET_OUT_BAD;
642
643
key = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_CFM,
644
target_container);
645
646
key->mdl_ver = hdr->mdl_ver;
647
key->opcode = hdr->opcode;
648
649
return FLOW_DISSECT_RET_OUT_GOOD;
650
}
651
652
static enum flow_dissect_ret
653
__skb_flow_dissect_gre(const struct sk_buff *skb,
654
struct flow_dissector_key_control *key_control,
655
struct flow_dissector *flow_dissector,
656
void *target_container, const void *data,
657
__be16 *p_proto, int *p_nhoff, int *p_hlen,
658
unsigned int flags)
659
{
660
struct flow_dissector_key_keyid *key_keyid;
661
struct gre_base_hdr *hdr, _hdr;
662
int offset = 0;
663
u16 gre_ver;
664
665
hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
666
data, *p_hlen, &_hdr);
667
if (!hdr)
668
return FLOW_DISSECT_RET_OUT_BAD;
669
670
/* Only look inside GRE without routing */
671
if (hdr->flags & GRE_ROUTING)
672
return FLOW_DISSECT_RET_OUT_GOOD;
673
674
/* Only look inside GRE for version 0 and 1 */
675
gre_ver = ntohs(hdr->flags & GRE_VERSION);
676
if (gre_ver > 1)
677
return FLOW_DISSECT_RET_OUT_GOOD;
678
679
*p_proto = hdr->protocol;
680
if (gre_ver) {
681
/* Version1 must be PPTP, and check the flags */
682
if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
683
return FLOW_DISSECT_RET_OUT_GOOD;
684
}
685
686
offset += sizeof(struct gre_base_hdr);
687
688
if (hdr->flags & GRE_CSUM)
689
offset += sizeof_field(struct gre_full_hdr, csum) +
690
sizeof_field(struct gre_full_hdr, reserved1);
691
692
if (hdr->flags & GRE_KEY) {
693
const __be32 *keyid;
694
__be32 _keyid;
695
696
keyid = __skb_header_pointer(skb, *p_nhoff + offset,
697
sizeof(_keyid),
698
data, *p_hlen, &_keyid);
699
if (!keyid)
700
return FLOW_DISSECT_RET_OUT_BAD;
701
702
if (dissector_uses_key(flow_dissector,
703
FLOW_DISSECTOR_KEY_GRE_KEYID)) {
704
key_keyid = skb_flow_dissector_target(flow_dissector,
705
FLOW_DISSECTOR_KEY_GRE_KEYID,
706
target_container);
707
if (gre_ver == 0)
708
key_keyid->keyid = *keyid;
709
else
710
key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
711
}
712
offset += sizeof_field(struct gre_full_hdr, key);
713
}
714
715
if (hdr->flags & GRE_SEQ)
716
offset += sizeof_field(struct pptp_gre_header, seq);
717
718
if (gre_ver == 0) {
719
if (*p_proto == htons(ETH_P_TEB)) {
720
const struct ethhdr *eth;
721
struct ethhdr _eth;
722
723
eth = __skb_header_pointer(skb, *p_nhoff + offset,
724
sizeof(_eth),
725
data, *p_hlen, &_eth);
726
if (!eth)
727
return FLOW_DISSECT_RET_OUT_BAD;
728
*p_proto = eth->h_proto;
729
offset += sizeof(*eth);
730
731
/* Cap headers that we access via pointers at the
732
* end of the Ethernet header as our maximum alignment
733
* at that point is only 2 bytes.
734
*/
735
if (NET_IP_ALIGN)
736
*p_hlen = *p_nhoff + offset;
737
}
738
} else { /* version 1, must be PPTP */
739
u8 _ppp_hdr[PPP_HDRLEN];
740
u8 *ppp_hdr;
741
742
if (hdr->flags & GRE_ACK)
743
offset += sizeof_field(struct pptp_gre_header, ack);
744
745
ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
746
sizeof(_ppp_hdr),
747
data, *p_hlen, _ppp_hdr);
748
if (!ppp_hdr)
749
return FLOW_DISSECT_RET_OUT_BAD;
750
751
switch (PPP_PROTOCOL(ppp_hdr)) {
752
case PPP_IP:
753
*p_proto = htons(ETH_P_IP);
754
break;
755
case PPP_IPV6:
756
*p_proto = htons(ETH_P_IPV6);
757
break;
758
default:
759
/* Could probably catch some more like MPLS */
760
break;
761
}
762
763
offset += PPP_HDRLEN;
764
}
765
766
*p_nhoff += offset;
767
key_control->flags |= FLOW_DIS_ENCAPSULATION;
768
if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
769
return FLOW_DISSECT_RET_OUT_GOOD;
770
771
return FLOW_DISSECT_RET_PROTO_AGAIN;
772
}
773
774
/**
775
* __skb_flow_dissect_batadv() - dissect batman-adv header
776
* @skb: sk_buff to with the batman-adv header
777
* @key_control: flow dissectors control key
778
* @data: raw buffer pointer to the packet, if NULL use skb->data
779
* @p_proto: pointer used to update the protocol to process next
780
* @p_nhoff: pointer used to update inner network header offset
781
* @hlen: packet header length
782
* @flags: any combination of FLOW_DISSECTOR_F_*
783
*
784
* ETH_P_BATMAN packets are tried to be dissected. Only
785
* &struct batadv_unicast packets are actually processed because they contain an
786
* inner ethernet header and are usually followed by actual network header. This
787
* allows the flow dissector to continue processing the packet.
788
*
789
* Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
790
* FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
791
* otherwise FLOW_DISSECT_RET_OUT_BAD
792
*/
793
static enum flow_dissect_ret
794
__skb_flow_dissect_batadv(const struct sk_buff *skb,
795
struct flow_dissector_key_control *key_control,
796
const void *data, __be16 *p_proto, int *p_nhoff,
797
int hlen, unsigned int flags)
798
{
799
struct {
800
struct batadv_unicast_packet batadv_unicast;
801
struct ethhdr eth;
802
} *hdr, _hdr;
803
804
hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
805
&_hdr);
806
if (!hdr)
807
return FLOW_DISSECT_RET_OUT_BAD;
808
809
if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
810
return FLOW_DISSECT_RET_OUT_BAD;
811
812
if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
813
return FLOW_DISSECT_RET_OUT_BAD;
814
815
*p_proto = hdr->eth.h_proto;
816
*p_nhoff += sizeof(*hdr);
817
818
key_control->flags |= FLOW_DIS_ENCAPSULATION;
819
if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
820
return FLOW_DISSECT_RET_OUT_GOOD;
821
822
return FLOW_DISSECT_RET_PROTO_AGAIN;
823
}
824
825
static void
826
__skb_flow_dissect_tcp(const struct sk_buff *skb,
827
struct flow_dissector *flow_dissector,
828
void *target_container, const void *data,
829
int thoff, int hlen)
830
{
831
struct flow_dissector_key_tcp *key_tcp;
832
struct tcphdr *th, _th;
833
834
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
835
return;
836
837
th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
838
if (!th)
839
return;
840
841
if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
842
return;
843
844
key_tcp = skb_flow_dissector_target(flow_dissector,
845
FLOW_DISSECTOR_KEY_TCP,
846
target_container);
847
key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
848
}
849
850
static void
851
__skb_flow_dissect_ports(const struct sk_buff *skb,
852
struct flow_dissector *flow_dissector,
853
void *target_container, const void *data,
854
int nhoff, u8 ip_proto, int hlen)
855
{
856
struct flow_dissector_key_ports_range *key_ports_range = NULL;
857
struct flow_dissector_key_ports *key_ports = NULL;
858
__be32 ports;
859
860
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
861
key_ports = skb_flow_dissector_target(flow_dissector,
862
FLOW_DISSECTOR_KEY_PORTS,
863
target_container);
864
865
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS_RANGE))
866
key_ports_range = skb_flow_dissector_target(flow_dissector,
867
FLOW_DISSECTOR_KEY_PORTS_RANGE,
868
target_container);
869
870
if (!key_ports && !key_ports_range)
871
return;
872
873
ports = skb_flow_get_ports(skb, nhoff, ip_proto, data, hlen);
874
875
if (key_ports)
876
key_ports->ports = ports;
877
878
if (key_ports_range)
879
key_ports_range->tp.ports = ports;
880
}
881
882
static void
883
__skb_flow_dissect_ipv4(const struct sk_buff *skb,
884
struct flow_dissector *flow_dissector,
885
void *target_container, const void *data,
886
const struct iphdr *iph)
887
{
888
struct flow_dissector_key_ip *key_ip;
889
890
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
891
return;
892
893
key_ip = skb_flow_dissector_target(flow_dissector,
894
FLOW_DISSECTOR_KEY_IP,
895
target_container);
896
key_ip->tos = iph->tos;
897
key_ip->ttl = iph->ttl;
898
}
899
900
static void
901
__skb_flow_dissect_ipv6(const struct sk_buff *skb,
902
struct flow_dissector *flow_dissector,
903
void *target_container, const void *data,
904
const struct ipv6hdr *iph)
905
{
906
struct flow_dissector_key_ip *key_ip;
907
908
if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
909
return;
910
911
key_ip = skb_flow_dissector_target(flow_dissector,
912
FLOW_DISSECTOR_KEY_IP,
913
target_container);
914
key_ip->tos = ipv6_get_dsfield(iph);
915
key_ip->ttl = iph->hop_limit;
916
}
917
918
/* Maximum number of protocol headers that can be parsed in
919
* __skb_flow_dissect
920
*/
921
#define MAX_FLOW_DISSECT_HDRS 15
922
923
static bool skb_flow_dissect_allowed(int *num_hdrs)
924
{
925
++*num_hdrs;
926
927
return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
928
}
929
930
static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
931
struct flow_dissector *flow_dissector,
932
void *target_container)
933
{
934
struct flow_dissector_key_ports_range *key_ports_range = NULL;
935
struct flow_dissector_key_ports *key_ports = NULL;
936
struct flow_dissector_key_control *key_control;
937
struct flow_dissector_key_basic *key_basic;
938
struct flow_dissector_key_addrs *key_addrs;
939
struct flow_dissector_key_tags *key_tags;
940
941
key_control = skb_flow_dissector_target(flow_dissector,
942
FLOW_DISSECTOR_KEY_CONTROL,
943
target_container);
944
key_control->thoff = flow_keys->thoff;
945
if (flow_keys->is_frag)
946
key_control->flags |= FLOW_DIS_IS_FRAGMENT;
947
if (flow_keys->is_first_frag)
948
key_control->flags |= FLOW_DIS_FIRST_FRAG;
949
if (flow_keys->is_encap)
950
key_control->flags |= FLOW_DIS_ENCAPSULATION;
951
952
key_basic = skb_flow_dissector_target(flow_dissector,
953
FLOW_DISSECTOR_KEY_BASIC,
954
target_container);
955
key_basic->n_proto = flow_keys->n_proto;
956
key_basic->ip_proto = flow_keys->ip_proto;
957
958
if (flow_keys->addr_proto == ETH_P_IP &&
959
dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
960
key_addrs = skb_flow_dissector_target(flow_dissector,
961
FLOW_DISSECTOR_KEY_IPV4_ADDRS,
962
target_container);
963
key_addrs->v4addrs.src = flow_keys->ipv4_src;
964
key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
965
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
966
} else if (flow_keys->addr_proto == ETH_P_IPV6 &&
967
dissector_uses_key(flow_dissector,
968
FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
969
key_addrs = skb_flow_dissector_target(flow_dissector,
970
FLOW_DISSECTOR_KEY_IPV6_ADDRS,
971
target_container);
972
memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src,
973
sizeof(key_addrs->v6addrs.src));
974
memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst,
975
sizeof(key_addrs->v6addrs.dst));
976
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
977
}
978
979
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
980
key_ports = skb_flow_dissector_target(flow_dissector,
981
FLOW_DISSECTOR_KEY_PORTS,
982
target_container);
983
key_ports->src = flow_keys->sport;
984
key_ports->dst = flow_keys->dport;
985
}
986
if (dissector_uses_key(flow_dissector,
987
FLOW_DISSECTOR_KEY_PORTS_RANGE)) {
988
key_ports_range = skb_flow_dissector_target(flow_dissector,
989
FLOW_DISSECTOR_KEY_PORTS_RANGE,
990
target_container);
991
key_ports_range->tp.src = flow_keys->sport;
992
key_ports_range->tp.dst = flow_keys->dport;
993
}
994
995
if (dissector_uses_key(flow_dissector,
996
FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
997
key_tags = skb_flow_dissector_target(flow_dissector,
998
FLOW_DISSECTOR_KEY_FLOW_LABEL,
999
target_container);
1000
key_tags->flow_label = ntohl(flow_keys->flow_label);
1001
}
1002
}
1003
1004
u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1005
__be16 proto, int nhoff, int hlen, unsigned int flags)
1006
{
1007
struct bpf_flow_keys *flow_keys = ctx->flow_keys;
1008
u32 result;
1009
1010
/* Pass parameters to the BPF program */
1011
memset(flow_keys, 0, sizeof(*flow_keys));
1012
flow_keys->n_proto = proto;
1013
flow_keys->nhoff = nhoff;
1014
flow_keys->thoff = flow_keys->nhoff;
1015
1016
BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
1017
(int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
1018
BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
1019
(int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1020
BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
1021
(int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
1022
flow_keys->flags = flags;
1023
1024
result = bpf_prog_run_pin_on_cpu(prog, ctx);
1025
1026
flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
1027
flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
1028
flow_keys->nhoff, hlen);
1029
1030
return result;
1031
}
1032
1033
static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
1034
{
1035
return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0;
1036
}
1037
1038
/**
1039
* __skb_flow_dissect - extract the flow_keys struct and return it
1040
* @net: associated network namespace, derived from @skb if NULL
1041
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
1042
* @flow_dissector: list of keys to dissect
1043
* @target_container: target structure to put dissected values into
1044
* @data: raw buffer pointer to the packet, if NULL use skb->data
1045
* @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
1046
* @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
1047
* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
1048
* @flags: flags that control the dissection process, e.g.
1049
* FLOW_DISSECTOR_F_STOP_AT_ENCAP.
1050
*
1051
* The function will try to retrieve individual keys into target specified
1052
* by flow_dissector from either the skbuff or a raw buffer specified by the
1053
* rest parameters.
1054
*
1055
* Caller must take care of zeroing target container memory.
1056
*/
1057
bool __skb_flow_dissect(const struct net *net,
1058
const struct sk_buff *skb,
1059
struct flow_dissector *flow_dissector,
1060
void *target_container, const void *data,
1061
__be16 proto, int nhoff, int hlen, unsigned int flags)
1062
{
1063
struct flow_dissector_key_control *key_control;
1064
struct flow_dissector_key_basic *key_basic;
1065
struct flow_dissector_key_addrs *key_addrs;
1066
struct flow_dissector_key_tags *key_tags;
1067
struct flow_dissector_key_vlan *key_vlan;
1068
enum flow_dissect_ret fdret;
1069
enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
1070
bool mpls_el = false;
1071
int mpls_lse = 0;
1072
int num_hdrs = 0;
1073
u8 ip_proto = 0;
1074
bool ret;
1075
1076
if (!data) {
1077
data = skb->data;
1078
proto = skb_vlan_tag_present(skb) ?
1079
skb->vlan_proto : skb->protocol;
1080
nhoff = skb_network_offset(skb);
1081
hlen = skb_headlen(skb);
1082
#if IS_ENABLED(CONFIG_NET_DSA)
1083
if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
1084
proto == htons(ETH_P_XDSA))) {
1085
struct metadata_dst *md_dst = skb_metadata_dst(skb);
1086
const struct dsa_device_ops *ops;
1087
int offset = 0;
1088
1089
ops = skb->dev->dsa_ptr->tag_ops;
1090
/* Only DSA header taggers break flow dissection */
1091
if (ops->needed_headroom &&
1092
(!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
1093
if (ops->flow_dissect)
1094
ops->flow_dissect(skb, &proto, &offset);
1095
else
1096
dsa_tag_generic_flow_dissect(skb,
1097
&proto,
1098
&offset);
1099
hlen -= offset;
1100
nhoff += offset;
1101
}
1102
}
1103
#endif
1104
}
1105
1106
/* It is ensured by skb_flow_dissector_init() that control key will
1107
* be always present.
1108
*/
1109
key_control = skb_flow_dissector_target(flow_dissector,
1110
FLOW_DISSECTOR_KEY_CONTROL,
1111
target_container);
1112
1113
/* It is ensured by skb_flow_dissector_init() that basic key will
1114
* be always present.
1115
*/
1116
key_basic = skb_flow_dissector_target(flow_dissector,
1117
FLOW_DISSECTOR_KEY_BASIC,
1118
target_container);
1119
1120
rcu_read_lock();
1121
1122
if (skb) {
1123
if (!net) {
1124
if (skb->dev)
1125
net = dev_net_rcu(skb->dev);
1126
else if (skb->sk)
1127
net = sock_net(skb->sk);
1128
}
1129
}
1130
1131
DEBUG_NET_WARN_ON_ONCE(!net);
1132
if (net) {
1133
enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
1134
struct bpf_prog_array *run_array;
1135
1136
run_array = rcu_dereference(init_net.bpf.run_array[type]);
1137
if (!run_array)
1138
run_array = rcu_dereference(net->bpf.run_array[type]);
1139
1140
if (run_array) {
1141
struct bpf_flow_keys flow_keys;
1142
struct bpf_flow_dissector ctx = {
1143
.flow_keys = &flow_keys,
1144
.data = data,
1145
.data_end = data + hlen,
1146
};
1147
__be16 n_proto = proto;
1148
struct bpf_prog *prog;
1149
u32 result;
1150
1151
if (skb) {
1152
ctx.skb = skb;
1153
/* we can't use 'proto' in the skb case
1154
* because it might be set to skb->vlan_proto
1155
* which has been pulled from the data
1156
*/
1157
n_proto = skb->protocol;
1158
}
1159
1160
prog = READ_ONCE(run_array->items[0].prog);
1161
result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
1162
hlen, flags);
1163
if (result != BPF_FLOW_DISSECTOR_CONTINUE) {
1164
__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1165
target_container);
1166
rcu_read_unlock();
1167
return result == BPF_OK;
1168
}
1169
}
1170
}
1171
1172
rcu_read_unlock();
1173
1174
if (dissector_uses_key(flow_dissector,
1175
FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1176
struct ethhdr *eth = eth_hdr(skb);
1177
struct flow_dissector_key_eth_addrs *key_eth_addrs;
1178
1179
key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1180
FLOW_DISSECTOR_KEY_ETH_ADDRS,
1181
target_container);
1182
memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs));
1183
}
1184
1185
if (dissector_uses_key(flow_dissector,
1186
FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
1187
struct flow_dissector_key_num_of_vlans *key_num_of_vlans;
1188
1189
key_num_of_vlans = skb_flow_dissector_target(flow_dissector,
1190
FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1191
target_container);
1192
key_num_of_vlans->num_of_vlans = 0;
1193
}
1194
1195
proto_again:
1196
fdret = FLOW_DISSECT_RET_CONTINUE;
1197
1198
switch (proto) {
1199
case htons(ETH_P_IP): {
1200
const struct iphdr *iph;
1201
struct iphdr _iph;
1202
1203
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1204
if (!iph || iph->ihl < 5) {
1205
fdret = FLOW_DISSECT_RET_OUT_BAD;
1206
break;
1207
}
1208
1209
nhoff += iph->ihl * 4;
1210
1211
ip_proto = iph->protocol;
1212
1213
if (dissector_uses_key(flow_dissector,
1214
FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1215
key_addrs = skb_flow_dissector_target(flow_dissector,
1216
FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1217
target_container);
1218
1219
memcpy(&key_addrs->v4addrs.src, &iph->saddr,
1220
sizeof(key_addrs->v4addrs.src));
1221
memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
1222
sizeof(key_addrs->v4addrs.dst));
1223
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1224
}
1225
1226
__skb_flow_dissect_ipv4(skb, flow_dissector,
1227
target_container, data, iph);
1228
1229
if (ip_is_fragment(iph)) {
1230
key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1231
1232
if (iph->frag_off & htons(IP_OFFSET)) {
1233
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1234
break;
1235
} else {
1236
key_control->flags |= FLOW_DIS_FIRST_FRAG;
1237
if (!(flags &
1238
FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1239
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1240
break;
1241
}
1242
}
1243
}
1244
1245
break;
1246
}
1247
case htons(ETH_P_IPV6): {
1248
const struct ipv6hdr *iph;
1249
struct ipv6hdr _iph;
1250
1251
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1252
if (!iph) {
1253
fdret = FLOW_DISSECT_RET_OUT_BAD;
1254
break;
1255
}
1256
1257
ip_proto = iph->nexthdr;
1258
nhoff += sizeof(struct ipv6hdr);
1259
1260
if (dissector_uses_key(flow_dissector,
1261
FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1262
key_addrs = skb_flow_dissector_target(flow_dissector,
1263
FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1264
target_container);
1265
1266
memcpy(&key_addrs->v6addrs.src, &iph->saddr,
1267
sizeof(key_addrs->v6addrs.src));
1268
memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
1269
sizeof(key_addrs->v6addrs.dst));
1270
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1271
}
1272
1273
if ((dissector_uses_key(flow_dissector,
1274
FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1275
(flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1276
ip6_flowlabel(iph)) {
1277
__be32 flow_label = ip6_flowlabel(iph);
1278
1279
if (dissector_uses_key(flow_dissector,
1280
FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1281
key_tags = skb_flow_dissector_target(flow_dissector,
1282
FLOW_DISSECTOR_KEY_FLOW_LABEL,
1283
target_container);
1284
key_tags->flow_label = ntohl(flow_label);
1285
}
1286
if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1287
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1288
break;
1289
}
1290
}
1291
1292
__skb_flow_dissect_ipv6(skb, flow_dissector,
1293
target_container, data, iph);
1294
1295
break;
1296
}
1297
case htons(ETH_P_8021AD):
1298
case htons(ETH_P_8021Q): {
1299
const struct vlan_hdr *vlan = NULL;
1300
struct vlan_hdr _vlan;
1301
__be16 saved_vlan_tpid = proto;
1302
1303
if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1304
skb && skb_vlan_tag_present(skb)) {
1305
proto = skb->protocol;
1306
} else {
1307
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1308
data, hlen, &_vlan);
1309
if (!vlan) {
1310
fdret = FLOW_DISSECT_RET_OUT_BAD;
1311
break;
1312
}
1313
1314
proto = vlan->h_vlan_encapsulated_proto;
1315
nhoff += sizeof(*vlan);
1316
}
1317
1318
if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
1319
!(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
1320
struct flow_dissector_key_num_of_vlans *key_nvs;
1321
1322
key_nvs = skb_flow_dissector_target(flow_dissector,
1323
FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1324
target_container);
1325
key_nvs->num_of_vlans++;
1326
}
1327
1328
if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1329
dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1330
} else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1331
dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1332
} else {
1333
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1334
break;
1335
}
1336
1337
if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1338
key_vlan = skb_flow_dissector_target(flow_dissector,
1339
dissector_vlan,
1340
target_container);
1341
1342
if (!vlan) {
1343
key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1344
key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1345
} else {
1346
key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1347
VLAN_VID_MASK;
1348
key_vlan->vlan_priority =
1349
(ntohs(vlan->h_vlan_TCI) &
1350
VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1351
}
1352
key_vlan->vlan_tpid = saved_vlan_tpid;
1353
key_vlan->vlan_eth_type = proto;
1354
}
1355
1356
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1357
break;
1358
}
1359
case htons(ETH_P_PPP_SES): {
1360
struct {
1361
struct pppoe_hdr hdr;
1362
__be16 proto;
1363
} *hdr, _hdr;
1364
u16 ppp_proto;
1365
1366
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1367
if (!hdr) {
1368
fdret = FLOW_DISSECT_RET_OUT_BAD;
1369
break;
1370
}
1371
1372
if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) {
1373
fdret = FLOW_DISSECT_RET_OUT_BAD;
1374
break;
1375
}
1376
1377
/* least significant bit of the most significant octet
1378
* indicates if protocol field was compressed
1379
*/
1380
ppp_proto = ntohs(hdr->proto);
1381
if (ppp_proto & 0x0100) {
1382
ppp_proto = ppp_proto >> 8;
1383
nhoff += PPPOE_SES_HLEN - 1;
1384
} else {
1385
nhoff += PPPOE_SES_HLEN;
1386
}
1387
1388
if (ppp_proto == PPP_IP) {
1389
proto = htons(ETH_P_IP);
1390
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1391
} else if (ppp_proto == PPP_IPV6) {
1392
proto = htons(ETH_P_IPV6);
1393
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1394
} else if (ppp_proto == PPP_MPLS_UC) {
1395
proto = htons(ETH_P_MPLS_UC);
1396
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1397
} else if (ppp_proto == PPP_MPLS_MC) {
1398
proto = htons(ETH_P_MPLS_MC);
1399
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1400
} else if (ppp_proto_is_valid(ppp_proto)) {
1401
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1402
} else {
1403
fdret = FLOW_DISSECT_RET_OUT_BAD;
1404
break;
1405
}
1406
1407
if (dissector_uses_key(flow_dissector,
1408
FLOW_DISSECTOR_KEY_PPPOE)) {
1409
struct flow_dissector_key_pppoe *key_pppoe;
1410
1411
key_pppoe = skb_flow_dissector_target(flow_dissector,
1412
FLOW_DISSECTOR_KEY_PPPOE,
1413
target_container);
1414
key_pppoe->session_id = hdr->hdr.sid;
1415
key_pppoe->ppp_proto = htons(ppp_proto);
1416
key_pppoe->type = htons(ETH_P_PPP_SES);
1417
}
1418
break;
1419
}
1420
case htons(ETH_P_TIPC): {
1421
struct tipc_basic_hdr *hdr, _hdr;
1422
1423
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1424
data, hlen, &_hdr);
1425
if (!hdr) {
1426
fdret = FLOW_DISSECT_RET_OUT_BAD;
1427
break;
1428
}
1429
1430
if (dissector_uses_key(flow_dissector,
1431
FLOW_DISSECTOR_KEY_TIPC)) {
1432
key_addrs = skb_flow_dissector_target(flow_dissector,
1433
FLOW_DISSECTOR_KEY_TIPC,
1434
target_container);
1435
key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1436
key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1437
}
1438
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1439
break;
1440
}
1441
1442
case htons(ETH_P_MPLS_UC):
1443
case htons(ETH_P_MPLS_MC):
1444
fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1445
target_container, data,
1446
nhoff, hlen, mpls_lse,
1447
&mpls_el);
1448
nhoff += sizeof(struct mpls_label);
1449
mpls_lse++;
1450
break;
1451
case htons(ETH_P_FCOE):
1452
if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1453
fdret = FLOW_DISSECT_RET_OUT_BAD;
1454
break;
1455
}
1456
1457
nhoff += FCOE_HEADER_LEN;
1458
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1459
break;
1460
1461
case htons(ETH_P_ARP):
1462
case htons(ETH_P_RARP):
1463
fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1464
target_container, data,
1465
nhoff, hlen);
1466
break;
1467
1468
case htons(ETH_P_BATMAN):
1469
fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1470
&proto, &nhoff, hlen, flags);
1471
break;
1472
1473
case htons(ETH_P_1588): {
1474
struct ptp_header *hdr, _hdr;
1475
1476
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
1477
hlen, &_hdr);
1478
if (!hdr) {
1479
fdret = FLOW_DISSECT_RET_OUT_BAD;
1480
break;
1481
}
1482
1483
nhoff += sizeof(struct ptp_header);
1484
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1485
break;
1486
}
1487
1488
case htons(ETH_P_PRP):
1489
case htons(ETH_P_HSR): {
1490
struct hsr_tag *hdr, _hdr;
1491
1492
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen,
1493
&_hdr);
1494
if (!hdr) {
1495
fdret = FLOW_DISSECT_RET_OUT_BAD;
1496
break;
1497
}
1498
1499
proto = hdr->encap_proto;
1500
nhoff += HSR_HLEN;
1501
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1502
break;
1503
}
1504
1505
case htons(ETH_P_CFM):
1506
fdret = __skb_flow_dissect_cfm(skb, flow_dissector,
1507
target_container, data,
1508
nhoff, hlen);
1509
break;
1510
1511
default:
1512
fdret = FLOW_DISSECT_RET_OUT_BAD;
1513
break;
1514
}
1515
1516
/* Process result of proto processing */
1517
switch (fdret) {
1518
case FLOW_DISSECT_RET_OUT_GOOD:
1519
goto out_good;
1520
case FLOW_DISSECT_RET_PROTO_AGAIN:
1521
if (skb_flow_dissect_allowed(&num_hdrs))
1522
goto proto_again;
1523
goto out_good;
1524
case FLOW_DISSECT_RET_CONTINUE:
1525
case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1526
break;
1527
case FLOW_DISSECT_RET_OUT_BAD:
1528
default:
1529
goto out_bad;
1530
}
1531
1532
ip_proto_again:
1533
fdret = FLOW_DISSECT_RET_CONTINUE;
1534
1535
switch (ip_proto) {
1536
case IPPROTO_GRE:
1537
if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1538
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1539
break;
1540
}
1541
1542
fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1543
target_container, data,
1544
&proto, &nhoff, &hlen, flags);
1545
break;
1546
1547
case NEXTHDR_HOP:
1548
case NEXTHDR_ROUTING:
1549
case NEXTHDR_DEST: {
1550
u8 _opthdr[2], *opthdr;
1551
1552
if (proto != htons(ETH_P_IPV6))
1553
break;
1554
1555
opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1556
data, hlen, &_opthdr);
1557
if (!opthdr) {
1558
fdret = FLOW_DISSECT_RET_OUT_BAD;
1559
break;
1560
}
1561
1562
ip_proto = opthdr[0];
1563
nhoff += (opthdr[1] + 1) << 3;
1564
1565
fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1566
break;
1567
}
1568
case NEXTHDR_FRAGMENT: {
1569
struct frag_hdr _fh, *fh;
1570
1571
if (proto != htons(ETH_P_IPV6))
1572
break;
1573
1574
fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1575
data, hlen, &_fh);
1576
1577
if (!fh) {
1578
fdret = FLOW_DISSECT_RET_OUT_BAD;
1579
break;
1580
}
1581
1582
key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1583
1584
nhoff += sizeof(_fh);
1585
ip_proto = fh->nexthdr;
1586
1587
if (!(fh->frag_off & htons(IP6_OFFSET))) {
1588
key_control->flags |= FLOW_DIS_FIRST_FRAG;
1589
if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1590
fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1591
break;
1592
}
1593
}
1594
1595
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1596
break;
1597
}
1598
case IPPROTO_IPIP:
1599
if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1600
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1601
break;
1602
}
1603
1604
proto = htons(ETH_P_IP);
1605
1606
key_control->flags |= FLOW_DIS_ENCAPSULATION;
1607
if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1608
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1609
break;
1610
}
1611
1612
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1613
break;
1614
1615
case IPPROTO_IPV6:
1616
if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1617
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1618
break;
1619
}
1620
1621
proto = htons(ETH_P_IPV6);
1622
1623
key_control->flags |= FLOW_DIS_ENCAPSULATION;
1624
if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1625
fdret = FLOW_DISSECT_RET_OUT_GOOD;
1626
break;
1627
}
1628
1629
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1630
break;
1631
1632
1633
case IPPROTO_MPLS:
1634
proto = htons(ETH_P_MPLS_UC);
1635
fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1636
break;
1637
1638
case IPPROTO_TCP:
1639
__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1640
data, nhoff, hlen);
1641
break;
1642
1643
case IPPROTO_ICMP:
1644
case IPPROTO_ICMPV6:
1645
__skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1646
data, nhoff, hlen);
1647
break;
1648
case IPPROTO_L2TP:
1649
__skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,
1650
data, nhoff, hlen);
1651
break;
1652
case IPPROTO_ESP:
1653
__skb_flow_dissect_esp(skb, flow_dissector, target_container,
1654
data, nhoff, hlen);
1655
break;
1656
case IPPROTO_AH:
1657
__skb_flow_dissect_ah(skb, flow_dissector, target_container,
1658
data, nhoff, hlen);
1659
break;
1660
default:
1661
break;
1662
}
1663
1664
if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1665
__skb_flow_dissect_ports(skb, flow_dissector, target_container,
1666
data, nhoff, ip_proto, hlen);
1667
1668
/* Process result of IP proto processing */
1669
switch (fdret) {
1670
case FLOW_DISSECT_RET_PROTO_AGAIN:
1671
if (skb_flow_dissect_allowed(&num_hdrs))
1672
goto proto_again;
1673
break;
1674
case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1675
if (skb_flow_dissect_allowed(&num_hdrs))
1676
goto ip_proto_again;
1677
break;
1678
case FLOW_DISSECT_RET_OUT_GOOD:
1679
case FLOW_DISSECT_RET_CONTINUE:
1680
break;
1681
case FLOW_DISSECT_RET_OUT_BAD:
1682
default:
1683
goto out_bad;
1684
}
1685
1686
out_good:
1687
ret = true;
1688
1689
out:
1690
key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1691
key_basic->n_proto = proto;
1692
key_basic->ip_proto = ip_proto;
1693
1694
return ret;
1695
1696
out_bad:
1697
ret = false;
1698
goto out;
1699
}
1700
EXPORT_SYMBOL(__skb_flow_dissect);
1701
1702
static siphash_aligned_key_t hashrnd;
1703
static __always_inline void __flow_hash_secret_init(void)
1704
{
1705
net_get_random_once(&hashrnd, sizeof(hashrnd));
1706
}
1707
1708
static const void *flow_keys_hash_start(const struct flow_keys *flow)
1709
{
1710
BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1711
return &flow->FLOW_KEYS_HASH_START_FIELD;
1712
}
1713
1714
static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1715
{
1716
size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1717
1718
BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1719
1720
switch (flow->control.addr_type) {
1721
case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1722
diff -= sizeof(flow->addrs.v4addrs);
1723
break;
1724
case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1725
diff -= sizeof(flow->addrs.v6addrs);
1726
break;
1727
case FLOW_DISSECTOR_KEY_TIPC:
1728
diff -= sizeof(flow->addrs.tipckey);
1729
break;
1730
}
1731
return sizeof(*flow) - diff;
1732
}
1733
1734
__be32 flow_get_u32_src(const struct flow_keys *flow)
1735
{
1736
switch (flow->control.addr_type) {
1737
case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1738
return flow->addrs.v4addrs.src;
1739
case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1740
return (__force __be32)ipv6_addr_hash(
1741
&flow->addrs.v6addrs.src);
1742
case FLOW_DISSECTOR_KEY_TIPC:
1743
return flow->addrs.tipckey.key;
1744
default:
1745
return 0;
1746
}
1747
}
1748
EXPORT_SYMBOL(flow_get_u32_src);
1749
1750
__be32 flow_get_u32_dst(const struct flow_keys *flow)
1751
{
1752
switch (flow->control.addr_type) {
1753
case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1754
return flow->addrs.v4addrs.dst;
1755
case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1756
return (__force __be32)ipv6_addr_hash(
1757
&flow->addrs.v6addrs.dst);
1758
default:
1759
return 0;
1760
}
1761
}
1762
EXPORT_SYMBOL(flow_get_u32_dst);
1763
1764
/* Sort the source and destination IP and the ports,
1765
* to have consistent hash within the two directions
1766
*/
1767
static inline void __flow_hash_consistentify(struct flow_keys *keys)
1768
{
1769
int addr_diff, i;
1770
1771
switch (keys->control.addr_type) {
1772
case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1773
if ((__force u32)keys->addrs.v4addrs.dst <
1774
(__force u32)keys->addrs.v4addrs.src)
1775
swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1776
1777
if ((__force u16)keys->ports.dst <
1778
(__force u16)keys->ports.src) {
1779
swap(keys->ports.src, keys->ports.dst);
1780
}
1781
break;
1782
case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1783
addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1784
&keys->addrs.v6addrs.src,
1785
sizeof(keys->addrs.v6addrs.dst));
1786
if (addr_diff < 0) {
1787
for (i = 0; i < 4; i++)
1788
swap(keys->addrs.v6addrs.src.s6_addr32[i],
1789
keys->addrs.v6addrs.dst.s6_addr32[i]);
1790
}
1791
if ((__force u16)keys->ports.dst <
1792
(__force u16)keys->ports.src) {
1793
swap(keys->ports.src, keys->ports.dst);
1794
}
1795
break;
1796
}
1797
}
1798
1799
static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1800
const siphash_key_t *keyval)
1801
{
1802
u32 hash;
1803
1804
__flow_hash_consistentify(keys);
1805
1806
hash = siphash(flow_keys_hash_start(keys),
1807
flow_keys_hash_length(keys), keyval);
1808
if (!hash)
1809
hash = 1;
1810
1811
return hash;
1812
}
1813
1814
u32 flow_hash_from_keys(struct flow_keys *keys)
1815
{
1816
__flow_hash_secret_init();
1817
return __flow_hash_from_keys(keys, &hashrnd);
1818
}
1819
EXPORT_SYMBOL(flow_hash_from_keys);
1820
1821
u32 flow_hash_from_keys_seed(struct flow_keys *keys,
1822
const siphash_key_t *keyval)
1823
{
1824
return __flow_hash_from_keys(keys, keyval);
1825
}
1826
EXPORT_SYMBOL(flow_hash_from_keys_seed);
1827
1828
static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1829
struct flow_keys *keys,
1830
const siphash_key_t *keyval)
1831
{
1832
skb_flow_dissect_flow_keys(skb, keys,
1833
FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1834
1835
return __flow_hash_from_keys(keys, keyval);
1836
}
1837
1838
struct _flow_keys_digest_data {
1839
__be16 n_proto;
1840
u8 ip_proto;
1841
u8 padding;
1842
__be32 ports;
1843
__be32 src;
1844
__be32 dst;
1845
};
1846
1847
void make_flow_keys_digest(struct flow_keys_digest *digest,
1848
const struct flow_keys *flow)
1849
{
1850
struct _flow_keys_digest_data *data =
1851
(struct _flow_keys_digest_data *)digest;
1852
1853
BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1854
1855
memset(digest, 0, sizeof(*digest));
1856
1857
data->n_proto = flow->basic.n_proto;
1858
data->ip_proto = flow->basic.ip_proto;
1859
data->ports = flow->ports.ports;
1860
data->src = flow->addrs.v4addrs.src;
1861
data->dst = flow->addrs.v4addrs.dst;
1862
}
1863
EXPORT_SYMBOL(make_flow_keys_digest);
1864
1865
static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1866
1867
u32 __skb_get_hash_symmetric_net(const struct net *net, const struct sk_buff *skb)
1868
{
1869
struct flow_keys keys;
1870
1871
__flow_hash_secret_init();
1872
1873
memset(&keys, 0, sizeof(keys));
1874
__skb_flow_dissect(net, skb, &flow_keys_dissector_symmetric,
1875
&keys, NULL, 0, 0, 0, 0);
1876
1877
return __flow_hash_from_keys(&keys, &hashrnd);
1878
}
1879
EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric_net);
1880
1881
/**
1882
* __skb_get_hash_net: calculate a flow hash
1883
* @net: associated network namespace, derived from @skb if NULL
1884
* @skb: sk_buff to calculate flow hash from
1885
*
1886
* This function calculates a flow hash based on src/dst addresses
1887
* and src/dst port numbers. Sets hash in skb to non-zero hash value
1888
* on success, zero indicates no valid hash. Also, sets l4_hash in skb
1889
* if hash is a canonical 4-tuple hash over transport ports.
1890
*/
1891
void __skb_get_hash_net(const struct net *net, struct sk_buff *skb)
1892
{
1893
struct flow_keys keys;
1894
u32 hash;
1895
1896
memset(&keys, 0, sizeof(keys));
1897
1898
__skb_flow_dissect(net, skb, &flow_keys_dissector,
1899
&keys, NULL, 0, 0, 0,
1900
FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1901
1902
__flow_hash_secret_init();
1903
1904
hash = __flow_hash_from_keys(&keys, &hashrnd);
1905
1906
__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1907
}
1908
EXPORT_SYMBOL(__skb_get_hash_net);
1909
1910
__u32 skb_get_hash_perturb(const struct sk_buff *skb,
1911
const siphash_key_t *perturb)
1912
{
1913
struct flow_keys keys;
1914
1915
return ___skb_get_hash(skb, &keys, perturb);
1916
}
1917
EXPORT_SYMBOL(skb_get_hash_perturb);
1918
1919
u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1920
const struct flow_keys_basic *keys, int hlen)
1921
{
1922
u32 poff = keys->control.thoff;
1923
1924
/* skip L4 headers for fragments after the first */
1925
if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1926
!(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1927
return poff;
1928
1929
switch (keys->basic.ip_proto) {
1930
case IPPROTO_TCP: {
1931
/* access doff as u8 to avoid unaligned access */
1932
const u8 *doff;
1933
u8 _doff;
1934
1935
doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1936
data, hlen, &_doff);
1937
if (!doff)
1938
return poff;
1939
1940
poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1941
break;
1942
}
1943
case IPPROTO_UDP:
1944
case IPPROTO_UDPLITE:
1945
poff += sizeof(struct udphdr);
1946
break;
1947
/* For the rest, we do not really care about header
1948
* extensions at this point for now.
1949
*/
1950
case IPPROTO_ICMP:
1951
poff += sizeof(struct icmphdr);
1952
break;
1953
case IPPROTO_ICMPV6:
1954
poff += sizeof(struct icmp6hdr);
1955
break;
1956
case IPPROTO_IGMP:
1957
poff += sizeof(struct igmphdr);
1958
break;
1959
case IPPROTO_DCCP:
1960
poff += sizeof(struct dccp_hdr);
1961
break;
1962
case IPPROTO_SCTP:
1963
poff += sizeof(struct sctphdr);
1964
break;
1965
}
1966
1967
return poff;
1968
}
1969
1970
/**
1971
* skb_get_poff - get the offset to the payload
1972
* @skb: sk_buff to get the payload offset from
1973
*
1974
* The function will get the offset to the payload as far as it could
1975
* be dissected. The main user is currently BPF, so that we can dynamically
1976
* truncate packets without needing to push actual payload to the user
1977
* space and can analyze headers only, instead.
1978
*/
1979
u32 skb_get_poff(const struct sk_buff *skb)
1980
{
1981
struct flow_keys_basic keys;
1982
1983
if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1984
NULL, 0, 0, 0, 0))
1985
return 0;
1986
1987
return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1988
}
1989
1990
__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1991
{
1992
memset(keys, 0, sizeof(*keys));
1993
1994
memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1995
sizeof(keys->addrs.v6addrs.src));
1996
memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1997
sizeof(keys->addrs.v6addrs.dst));
1998
keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1999
keys->ports.src = fl6->fl6_sport;
2000
keys->ports.dst = fl6->fl6_dport;
2001
keys->keyid.keyid = fl6->fl6_gre_key;
2002
keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
2003
keys->basic.ip_proto = fl6->flowi6_proto;
2004
2005
return flow_hash_from_keys(keys);
2006
}
2007
EXPORT_SYMBOL(__get_hash_from_flowi6);
2008
2009
static const struct flow_dissector_key flow_keys_dissector_keys[] = {
2010
{
2011
.key_id = FLOW_DISSECTOR_KEY_CONTROL,
2012
.offset = offsetof(struct flow_keys, control),
2013
},
2014
{
2015
.key_id = FLOW_DISSECTOR_KEY_BASIC,
2016
.offset = offsetof(struct flow_keys, basic),
2017
},
2018
{
2019
.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
2020
.offset = offsetof(struct flow_keys, addrs.v4addrs),
2021
},
2022
{
2023
.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
2024
.offset = offsetof(struct flow_keys, addrs.v6addrs),
2025
},
2026
{
2027
.key_id = FLOW_DISSECTOR_KEY_TIPC,
2028
.offset = offsetof(struct flow_keys, addrs.tipckey),
2029
},
2030
{
2031
.key_id = FLOW_DISSECTOR_KEY_PORTS,
2032
.offset = offsetof(struct flow_keys, ports),
2033
},
2034
{
2035
.key_id = FLOW_DISSECTOR_KEY_VLAN,
2036
.offset = offsetof(struct flow_keys, vlan),
2037
},
2038
{
2039
.key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
2040
.offset = offsetof(struct flow_keys, tags),
2041
},
2042
{
2043
.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
2044
.offset = offsetof(struct flow_keys, keyid),
2045
},
2046
};
2047
2048
static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
2049
{
2050
.key_id = FLOW_DISSECTOR_KEY_CONTROL,
2051
.offset = offsetof(struct flow_keys, control),
2052
},
2053
{
2054
.key_id = FLOW_DISSECTOR_KEY_BASIC,
2055
.offset = offsetof(struct flow_keys, basic),
2056
},
2057
{
2058
.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
2059
.offset = offsetof(struct flow_keys, addrs.v4addrs),
2060
},
2061
{
2062
.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
2063
.offset = offsetof(struct flow_keys, addrs.v6addrs),
2064
},
2065
{
2066
.key_id = FLOW_DISSECTOR_KEY_PORTS,
2067
.offset = offsetof(struct flow_keys, ports),
2068
},
2069
};
2070
2071
static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
2072
{
2073
.key_id = FLOW_DISSECTOR_KEY_CONTROL,
2074
.offset = offsetof(struct flow_keys, control),
2075
},
2076
{
2077
.key_id = FLOW_DISSECTOR_KEY_BASIC,
2078
.offset = offsetof(struct flow_keys, basic),
2079
},
2080
};
2081
2082
struct flow_dissector flow_keys_dissector __read_mostly;
2083
EXPORT_SYMBOL(flow_keys_dissector);
2084
2085
struct flow_dissector flow_keys_basic_dissector __read_mostly;
2086
EXPORT_SYMBOL(flow_keys_basic_dissector);
2087
2088
static int __init init_default_flow_dissectors(void)
2089
{
2090
skb_flow_dissector_init(&flow_keys_dissector,
2091
flow_keys_dissector_keys,
2092
ARRAY_SIZE(flow_keys_dissector_keys));
2093
skb_flow_dissector_init(&flow_keys_dissector_symmetric,
2094
flow_keys_dissector_symmetric_keys,
2095
ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
2096
skb_flow_dissector_init(&flow_keys_basic_dissector,
2097
flow_keys_basic_dissector_keys,
2098
ARRAY_SIZE(flow_keys_basic_dissector_keys));
2099
return 0;
2100
}
2101
core_initcall(init_default_flow_dissectors);
2102
2103