Merge tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6-microblaze.git] / net / core / flow_dissector.c
1 #include <linux/kernel.h>
2 #include <linux/skbuff.h>
3 #include <linux/export.h>
4 #include <linux/ip.h>
5 #include <linux/ipv6.h>
6 #include <linux/if_vlan.h>
7 #include <net/ip.h>
8 #include <net/ipv6.h>
9 #include <net/gre.h>
10 #include <net/pptp.h>
11 #include <linux/igmp.h>
12 #include <linux/icmp.h>
13 #include <linux/sctp.h>
14 #include <linux/dccp.h>
15 #include <linux/if_tunnel.h>
16 #include <linux/if_pppox.h>
17 #include <linux/ppp_defs.h>
18 #include <linux/stddef.h>
19 #include <linux/if_ether.h>
20 #include <linux/mpls.h>
21 #include <net/flow_dissector.h>
22 #include <scsi/fc/fc_fcoe.h>
23
24 static void dissector_set_key(struct flow_dissector *flow_dissector,
25                               enum flow_dissector_key_id key_id)
26 {
27         flow_dissector->used_keys |= (1 << key_id);
28 }
29
30 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
31                              const struct flow_dissector_key *key,
32                              unsigned int key_count)
33 {
34         unsigned int i;
35
36         memset(flow_dissector, 0, sizeof(*flow_dissector));
37
38         for (i = 0; i < key_count; i++, key++) {
39                 /* User should make sure that every key target offset is withing
40                  * boundaries of unsigned short.
41                  */
42                 BUG_ON(key->offset > USHRT_MAX);
43                 BUG_ON(dissector_uses_key(flow_dissector,
44                                           key->key_id));
45
46                 dissector_set_key(flow_dissector, key->key_id);
47                 flow_dissector->offset[key->key_id] = key->offset;
48         }
49
50         /* Ensure that the dissector always includes control and basic key.
51          * That way we are able to avoid handling lack of these in fast path.
52          */
53         BUG_ON(!dissector_uses_key(flow_dissector,
54                                    FLOW_DISSECTOR_KEY_CONTROL));
55         BUG_ON(!dissector_uses_key(flow_dissector,
56                                    FLOW_DISSECTOR_KEY_BASIC));
57 }
58 EXPORT_SYMBOL(skb_flow_dissector_init);
59
60 /**
61  * skb_flow_get_be16 - extract be16 entity
62  * @skb: sk_buff to extract from
63  * @poff: offset to extract at
64  * @data: raw buffer pointer to the packet
65  * @hlen: packet header length
66  *
67  * The function will try to retrieve a be32 entity at
68  * offset poff
69  */
70 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
71                                 void *data, int hlen)
72 {
73         __be16 *u, _u;
74
75         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
76         if (u)
77                 return *u;
78
79         return 0;
80 }
81
82 /**
83  * __skb_flow_get_ports - extract the upper layer ports and return them
84  * @skb: sk_buff to extract the ports from
85  * @thoff: transport header offset
86  * @ip_proto: protocol for which to get port offset
87  * @data: raw buffer pointer to the packet, if NULL use skb->data
88  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
89  *
90  * The function will try to retrieve the ports at offset thoff + poff where poff
91  * is the protocol port offset returned from proto_ports_offset
92  */
93 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
94                             void *data, int hlen)
95 {
96         int poff = proto_ports_offset(ip_proto);
97
98         if (!data) {
99                 data = skb->data;
100                 hlen = skb_headlen(skb);
101         }
102
103         if (poff >= 0) {
104                 __be32 *ports, _ports;
105
106                 ports = __skb_header_pointer(skb, thoff + poff,
107                                              sizeof(_ports), data, hlen, &_ports);
108                 if (ports)
109                         return *ports;
110         }
111
112         return 0;
113 }
114 EXPORT_SYMBOL(__skb_flow_get_ports);
115
116 enum flow_dissect_ret {
117         FLOW_DISSECT_RET_OUT_GOOD,
118         FLOW_DISSECT_RET_OUT_BAD,
119         FLOW_DISSECT_RET_OUT_PROTO_AGAIN,
120 };
121
122 static enum flow_dissect_ret
123 __skb_flow_dissect_mpls(const struct sk_buff *skb,
124                         struct flow_dissector *flow_dissector,
125                         void *target_container, void *data, int nhoff, int hlen)
126 {
127         struct flow_dissector_key_keyid *key_keyid;
128         struct mpls_label *hdr, _hdr[2];
129         u32 entry, label;
130
131         if (!dissector_uses_key(flow_dissector,
132                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
133             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
134                 return FLOW_DISSECT_RET_OUT_GOOD;
135
136         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
137                                    hlen, &_hdr);
138         if (!hdr)
139                 return FLOW_DISSECT_RET_OUT_BAD;
140
141         entry = ntohl(hdr[0].entry);
142         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
143
144         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
145                 struct flow_dissector_key_mpls *key_mpls;
146
147                 key_mpls = skb_flow_dissector_target(flow_dissector,
148                                                      FLOW_DISSECTOR_KEY_MPLS,
149                                                      target_container);
150                 key_mpls->mpls_label = label;
151                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
152                                         >> MPLS_LS_TTL_SHIFT;
153                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
154                                         >> MPLS_LS_TC_SHIFT;
155                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
156                                         >> MPLS_LS_S_SHIFT;
157         }
158
159         if (label == MPLS_LABEL_ENTROPY) {
160                 key_keyid = skb_flow_dissector_target(flow_dissector,
161                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
162                                                       target_container);
163                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
164         }
165         return FLOW_DISSECT_RET_OUT_GOOD;
166 }
167
168 static enum flow_dissect_ret
169 __skb_flow_dissect_arp(const struct sk_buff *skb,
170                        struct flow_dissector *flow_dissector,
171                        void *target_container, void *data, int nhoff, int hlen)
172 {
173         struct flow_dissector_key_arp *key_arp;
174         struct {
175                 unsigned char ar_sha[ETH_ALEN];
176                 unsigned char ar_sip[4];
177                 unsigned char ar_tha[ETH_ALEN];
178                 unsigned char ar_tip[4];
179         } *arp_eth, _arp_eth;
180         const struct arphdr *arp;
181         struct arphdr _arp;
182
183         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
184                 return FLOW_DISSECT_RET_OUT_GOOD;
185
186         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
187                                    hlen, &_arp);
188         if (!arp)
189                 return FLOW_DISSECT_RET_OUT_BAD;
190
191         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
192             arp->ar_pro != htons(ETH_P_IP) ||
193             arp->ar_hln != ETH_ALEN ||
194             arp->ar_pln != 4 ||
195             (arp->ar_op != htons(ARPOP_REPLY) &&
196              arp->ar_op != htons(ARPOP_REQUEST)))
197                 return FLOW_DISSECT_RET_OUT_BAD;
198
199         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
200                                        sizeof(_arp_eth), data,
201                                        hlen, &_arp_eth);
202         if (!arp_eth)
203                 return FLOW_DISSECT_RET_OUT_BAD;
204
205         key_arp = skb_flow_dissector_target(flow_dissector,
206                                             FLOW_DISSECTOR_KEY_ARP,
207                                             target_container);
208
209         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
210         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
211
212         /* Only store the lower byte of the opcode;
213          * this covers ARPOP_REPLY and ARPOP_REQUEST.
214          */
215         key_arp->op = ntohs(arp->ar_op) & 0xff;
216
217         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
218         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
219
220         return FLOW_DISSECT_RET_OUT_GOOD;
221 }
222
223 static enum flow_dissect_ret
224 __skb_flow_dissect_gre(const struct sk_buff *skb,
225                        struct flow_dissector_key_control *key_control,
226                        struct flow_dissector *flow_dissector,
227                        void *target_container, void *data,
228                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
229                        unsigned int flags)
230 {
231         struct flow_dissector_key_keyid *key_keyid;
232         struct gre_base_hdr *hdr, _hdr;
233         int offset = 0;
234         u16 gre_ver;
235
236         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
237                                    data, *p_hlen, &_hdr);
238         if (!hdr)
239                 return FLOW_DISSECT_RET_OUT_BAD;
240
241         /* Only look inside GRE without routing */
242         if (hdr->flags & GRE_ROUTING)
243                 return FLOW_DISSECT_RET_OUT_GOOD;
244
245         /* Only look inside GRE for version 0 and 1 */
246         gre_ver = ntohs(hdr->flags & GRE_VERSION);
247         if (gre_ver > 1)
248                 return FLOW_DISSECT_RET_OUT_GOOD;
249
250         *p_proto = hdr->protocol;
251         if (gre_ver) {
252                 /* Version1 must be PPTP, and check the flags */
253                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
254                         return FLOW_DISSECT_RET_OUT_GOOD;
255         }
256
257         offset += sizeof(struct gre_base_hdr);
258
259         if (hdr->flags & GRE_CSUM)
260                 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
261                           sizeof(((struct gre_full_hdr *) 0)->reserved1);
262
263         if (hdr->flags & GRE_KEY) {
264                 const __be32 *keyid;
265                 __be32 _keyid;
266
267                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
268                                              sizeof(_keyid),
269                                              data, *p_hlen, &_keyid);
270                 if (!keyid)
271                         return FLOW_DISSECT_RET_OUT_BAD;
272
273                 if (dissector_uses_key(flow_dissector,
274                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
275                         key_keyid = skb_flow_dissector_target(flow_dissector,
276                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
277                                                               target_container);
278                         if (gre_ver == 0)
279                                 key_keyid->keyid = *keyid;
280                         else
281                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
282                 }
283                 offset += sizeof(((struct gre_full_hdr *) 0)->key);
284         }
285
286         if (hdr->flags & GRE_SEQ)
287                 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
288
289         if (gre_ver == 0) {
290                 if (*p_proto == htons(ETH_P_TEB)) {
291                         const struct ethhdr *eth;
292                         struct ethhdr _eth;
293
294                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
295                                                    sizeof(_eth),
296                                                    data, *p_hlen, &_eth);
297                         if (!eth)
298                                 return FLOW_DISSECT_RET_OUT_BAD;
299                         *p_proto = eth->h_proto;
300                         offset += sizeof(*eth);
301
302                         /* Cap headers that we access via pointers at the
303                          * end of the Ethernet header as our maximum alignment
304                          * at that point is only 2 bytes.
305                          */
306                         if (NET_IP_ALIGN)
307                                 *p_hlen = *p_nhoff + offset;
308                 }
309         } else { /* version 1, must be PPTP */
310                 u8 _ppp_hdr[PPP_HDRLEN];
311                 u8 *ppp_hdr;
312
313                 if (hdr->flags & GRE_ACK)
314                         offset += sizeof(((struct pptp_gre_header *) 0)->ack);
315
316                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
317                                                sizeof(_ppp_hdr),
318                                                data, *p_hlen, _ppp_hdr);
319                 if (!ppp_hdr)
320                         return FLOW_DISSECT_RET_OUT_BAD;
321
322                 switch (PPP_PROTOCOL(ppp_hdr)) {
323                 case PPP_IP:
324                         *p_proto = htons(ETH_P_IP);
325                         break;
326                 case PPP_IPV6:
327                         *p_proto = htons(ETH_P_IPV6);
328                         break;
329                 default:
330                         /* Could probably catch some more like MPLS */
331                         break;
332                 }
333
334                 offset += PPP_HDRLEN;
335         }
336
337         *p_nhoff += offset;
338         key_control->flags |= FLOW_DIS_ENCAPSULATION;
339         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
340                 return FLOW_DISSECT_RET_OUT_GOOD;
341
342         return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;
343 }
344
345 /**
346  * __skb_flow_dissect - extract the flow_keys struct and return it
347  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
348  * @flow_dissector: list of keys to dissect
349  * @target_container: target structure to put dissected values into
350  * @data: raw buffer pointer to the packet, if NULL use skb->data
351  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
352  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
353  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
354  *
355  * The function will try to retrieve individual keys into target specified
356  * by flow_dissector from either the skbuff or a raw buffer specified by the
357  * rest parameters.
358  *
359  * Caller must take care of zeroing target container memory.
360  */
361 bool __skb_flow_dissect(const struct sk_buff *skb,
362                         struct flow_dissector *flow_dissector,
363                         void *target_container,
364                         void *data, __be16 proto, int nhoff, int hlen,
365                         unsigned int flags)
366 {
367         struct flow_dissector_key_control *key_control;
368         struct flow_dissector_key_basic *key_basic;
369         struct flow_dissector_key_addrs *key_addrs;
370         struct flow_dissector_key_ports *key_ports;
371         struct flow_dissector_key_icmp *key_icmp;
372         struct flow_dissector_key_tags *key_tags;
373         struct flow_dissector_key_vlan *key_vlan;
374         bool skip_vlan = false;
375         u8 ip_proto = 0;
376         bool ret;
377
378         if (!data) {
379                 data = skb->data;
380                 proto = skb_vlan_tag_present(skb) ?
381                          skb->vlan_proto : skb->protocol;
382                 nhoff = skb_network_offset(skb);
383                 hlen = skb_headlen(skb);
384         }
385
386         /* It is ensured by skb_flow_dissector_init() that control key will
387          * be always present.
388          */
389         key_control = skb_flow_dissector_target(flow_dissector,
390                                                 FLOW_DISSECTOR_KEY_CONTROL,
391                                                 target_container);
392
393         /* It is ensured by skb_flow_dissector_init() that basic key will
394          * be always present.
395          */
396         key_basic = skb_flow_dissector_target(flow_dissector,
397                                               FLOW_DISSECTOR_KEY_BASIC,
398                                               target_container);
399
400         if (dissector_uses_key(flow_dissector,
401                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
402                 struct ethhdr *eth = eth_hdr(skb);
403                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
404
405                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
406                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
407                                                           target_container);
408                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
409         }
410
411 proto_again:
412         switch (proto) {
413         case htons(ETH_P_IP): {
414                 const struct iphdr *iph;
415                 struct iphdr _iph;
416 ip:
417                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
418                 if (!iph || iph->ihl < 5)
419                         goto out_bad;
420                 nhoff += iph->ihl * 4;
421
422                 ip_proto = iph->protocol;
423
424                 if (dissector_uses_key(flow_dissector,
425                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
426                         key_addrs = skb_flow_dissector_target(flow_dissector,
427                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
428                                                               target_container);
429
430                         memcpy(&key_addrs->v4addrs, &iph->saddr,
431                                sizeof(key_addrs->v4addrs));
432                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
433                 }
434
435                 if (ip_is_fragment(iph)) {
436                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
437
438                         if (iph->frag_off & htons(IP_OFFSET)) {
439                                 goto out_good;
440                         } else {
441                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
442                                 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
443                                         goto out_good;
444                         }
445                 }
446
447                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
448                         goto out_good;
449
450                 break;
451         }
452         case htons(ETH_P_IPV6): {
453                 const struct ipv6hdr *iph;
454                 struct ipv6hdr _iph;
455
456 ipv6:
457                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
458                 if (!iph)
459                         goto out_bad;
460
461                 ip_proto = iph->nexthdr;
462                 nhoff += sizeof(struct ipv6hdr);
463
464                 if (dissector_uses_key(flow_dissector,
465                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
466                         key_addrs = skb_flow_dissector_target(flow_dissector,
467                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
468                                                               target_container);
469
470                         memcpy(&key_addrs->v6addrs, &iph->saddr,
471                                sizeof(key_addrs->v6addrs));
472                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
473                 }
474
475                 if ((dissector_uses_key(flow_dissector,
476                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
477                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
478                     ip6_flowlabel(iph)) {
479                         __be32 flow_label = ip6_flowlabel(iph);
480
481                         if (dissector_uses_key(flow_dissector,
482                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
483                                 key_tags = skb_flow_dissector_target(flow_dissector,
484                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
485                                                                      target_container);
486                                 key_tags->flow_label = ntohl(flow_label);
487                         }
488                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
489                                 goto out_good;
490                 }
491
492                 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
493                         goto out_good;
494
495                 break;
496         }
497         case htons(ETH_P_8021AD):
498         case htons(ETH_P_8021Q): {
499                 const struct vlan_hdr *vlan;
500                 struct vlan_hdr _vlan;
501                 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
502
503                 if (vlan_tag_present)
504                         proto = skb->protocol;
505
506                 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
507                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
508                                                     data, hlen, &_vlan);
509                         if (!vlan)
510                                 goto out_bad;
511                         proto = vlan->h_vlan_encapsulated_proto;
512                         nhoff += sizeof(*vlan);
513                         if (skip_vlan)
514                                 goto proto_again;
515                 }
516
517                 skip_vlan = true;
518                 if (dissector_uses_key(flow_dissector,
519                                        FLOW_DISSECTOR_KEY_VLAN)) {
520                         key_vlan = skb_flow_dissector_target(flow_dissector,
521                                                              FLOW_DISSECTOR_KEY_VLAN,
522                                                              target_container);
523
524                         if (vlan_tag_present) {
525                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
526                                 key_vlan->vlan_priority =
527                                         (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
528                         } else {
529                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
530                                         VLAN_VID_MASK;
531                                 key_vlan->vlan_priority =
532                                         (ntohs(vlan->h_vlan_TCI) &
533                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
534                         }
535                 }
536
537                 goto proto_again;
538         }
539         case htons(ETH_P_PPP_SES): {
540                 struct {
541                         struct pppoe_hdr hdr;
542                         __be16 proto;
543                 } *hdr, _hdr;
544                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
545                 if (!hdr)
546                         goto out_bad;
547                 proto = hdr->proto;
548                 nhoff += PPPOE_SES_HLEN;
549                 switch (proto) {
550                 case htons(PPP_IP):
551                         goto ip;
552                 case htons(PPP_IPV6):
553                         goto ipv6;
554                 default:
555                         goto out_bad;
556                 }
557         }
558         case htons(ETH_P_TIPC): {
559                 struct {
560                         __be32 pre[3];
561                         __be32 srcnode;
562                 } *hdr, _hdr;
563                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
564                 if (!hdr)
565                         goto out_bad;
566
567                 if (dissector_uses_key(flow_dissector,
568                                        FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
569                         key_addrs = skb_flow_dissector_target(flow_dissector,
570                                                               FLOW_DISSECTOR_KEY_TIPC_ADDRS,
571                                                               target_container);
572                         key_addrs->tipcaddrs.srcnode = hdr->srcnode;
573                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
574                 }
575                 goto out_good;
576         }
577
578         case htons(ETH_P_MPLS_UC):
579         case htons(ETH_P_MPLS_MC):
580 mpls:
581                 switch (__skb_flow_dissect_mpls(skb, flow_dissector,
582                                                 target_container, data,
583                                                 nhoff, hlen)) {
584                 case FLOW_DISSECT_RET_OUT_GOOD:
585                         goto out_good;
586                 case FLOW_DISSECT_RET_OUT_BAD:
587                 default:
588                         goto out_bad;
589                 }
590         case htons(ETH_P_FCOE):
591                 if ((hlen - nhoff) < FCOE_HEADER_LEN)
592                         goto out_bad;
593
594                 nhoff += FCOE_HEADER_LEN;
595                 goto out_good;
596
597         case htons(ETH_P_ARP):
598         case htons(ETH_P_RARP):
599                 switch (__skb_flow_dissect_arp(skb, flow_dissector,
600                                                target_container, data,
601                                                nhoff, hlen)) {
602                 case FLOW_DISSECT_RET_OUT_GOOD:
603                         goto out_good;
604                 case FLOW_DISSECT_RET_OUT_BAD:
605                 default:
606                         goto out_bad;
607                 }
608         default:
609                 goto out_bad;
610         }
611
612 ip_proto_again:
613         switch (ip_proto) {
614         case IPPROTO_GRE:
615                 switch (__skb_flow_dissect_gre(skb, key_control, flow_dissector,
616                                                target_container, data,
617                                                &proto, &nhoff, &hlen, flags)) {
618                 case FLOW_DISSECT_RET_OUT_GOOD:
619                         goto out_good;
620                 case FLOW_DISSECT_RET_OUT_BAD:
621                         goto out_bad;
622                 case FLOW_DISSECT_RET_OUT_PROTO_AGAIN:
623                         goto proto_again;
624                 }
625         case NEXTHDR_HOP:
626         case NEXTHDR_ROUTING:
627         case NEXTHDR_DEST: {
628                 u8 _opthdr[2], *opthdr;
629
630                 if (proto != htons(ETH_P_IPV6))
631                         break;
632
633                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
634                                               data, hlen, &_opthdr);
635                 if (!opthdr)
636                         goto out_bad;
637
638                 ip_proto = opthdr[0];
639                 nhoff += (opthdr[1] + 1) << 3;
640
641                 goto ip_proto_again;
642         }
643         case NEXTHDR_FRAGMENT: {
644                 struct frag_hdr _fh, *fh;
645
646                 if (proto != htons(ETH_P_IPV6))
647                         break;
648
649                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
650                                           data, hlen, &_fh);
651
652                 if (!fh)
653                         goto out_bad;
654
655                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
656
657                 nhoff += sizeof(_fh);
658                 ip_proto = fh->nexthdr;
659
660                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
661                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
662                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
663                                 goto ip_proto_again;
664                 }
665                 goto out_good;
666         }
667         case IPPROTO_IPIP:
668                 proto = htons(ETH_P_IP);
669
670                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
671                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
672                         goto out_good;
673
674                 goto ip;
675         case IPPROTO_IPV6:
676                 proto = htons(ETH_P_IPV6);
677
678                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
679                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
680                         goto out_good;
681
682                 goto ipv6;
683         case IPPROTO_MPLS:
684                 proto = htons(ETH_P_MPLS_UC);
685                 goto mpls;
686         default:
687                 break;
688         }
689
690         if (dissector_uses_key(flow_dissector,
691                                FLOW_DISSECTOR_KEY_PORTS)) {
692                 key_ports = skb_flow_dissector_target(flow_dissector,
693                                                       FLOW_DISSECTOR_KEY_PORTS,
694                                                       target_container);
695                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
696                                                         data, hlen);
697         }
698
699         if (dissector_uses_key(flow_dissector,
700                                FLOW_DISSECTOR_KEY_ICMP)) {
701                 key_icmp = skb_flow_dissector_target(flow_dissector,
702                                                      FLOW_DISSECTOR_KEY_ICMP,
703                                                      target_container);
704                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
705         }
706
707 out_good:
708         ret = true;
709
710         key_control->thoff = (u16)nhoff;
711 out:
712         key_basic->n_proto = proto;
713         key_basic->ip_proto = ip_proto;
714
715         return ret;
716
717 out_bad:
718         ret = false;
719         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
720         goto out;
721 }
722 EXPORT_SYMBOL(__skb_flow_dissect);
723
724 static u32 hashrnd __read_mostly;
725 static __always_inline void __flow_hash_secret_init(void)
726 {
727         net_get_random_once(&hashrnd, sizeof(hashrnd));
728 }
729
730 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
731                                              u32 keyval)
732 {
733         return jhash2(words, length, keyval);
734 }
735
736 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
737 {
738         const void *p = flow;
739
740         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
741         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
742 }
743
744 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
745 {
746         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
747         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
748         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
749                      sizeof(*flow) - sizeof(flow->addrs));
750
751         switch (flow->control.addr_type) {
752         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
753                 diff -= sizeof(flow->addrs.v4addrs);
754                 break;
755         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
756                 diff -= sizeof(flow->addrs.v6addrs);
757                 break;
758         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
759                 diff -= sizeof(flow->addrs.tipcaddrs);
760                 break;
761         }
762         return (sizeof(*flow) - diff) / sizeof(u32);
763 }
764
765 __be32 flow_get_u32_src(const struct flow_keys *flow)
766 {
767         switch (flow->control.addr_type) {
768         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
769                 return flow->addrs.v4addrs.src;
770         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
771                 return (__force __be32)ipv6_addr_hash(
772                         &flow->addrs.v6addrs.src);
773         case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
774                 return flow->addrs.tipcaddrs.srcnode;
775         default:
776                 return 0;
777         }
778 }
779 EXPORT_SYMBOL(flow_get_u32_src);
780
781 __be32 flow_get_u32_dst(const struct flow_keys *flow)
782 {
783         switch (flow->control.addr_type) {
784         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
785                 return flow->addrs.v4addrs.dst;
786         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
787                 return (__force __be32)ipv6_addr_hash(
788                         &flow->addrs.v6addrs.dst);
789         default:
790                 return 0;
791         }
792 }
793 EXPORT_SYMBOL(flow_get_u32_dst);
794
795 static inline void __flow_hash_consistentify(struct flow_keys *keys)
796 {
797         int addr_diff, i;
798
799         switch (keys->control.addr_type) {
800         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
801                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
802                             (__force u32)keys->addrs.v4addrs.src;
803                 if ((addr_diff < 0) ||
804                     (addr_diff == 0 &&
805                      ((__force u16)keys->ports.dst <
806                       (__force u16)keys->ports.src))) {
807                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
808                         swap(keys->ports.src, keys->ports.dst);
809                 }
810                 break;
811         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
812                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
813                                    &keys->addrs.v6addrs.src,
814                                    sizeof(keys->addrs.v6addrs.dst));
815                 if ((addr_diff < 0) ||
816                     (addr_diff == 0 &&
817                      ((__force u16)keys->ports.dst <
818                       (__force u16)keys->ports.src))) {
819                         for (i = 0; i < 4; i++)
820                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
821                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
822                         swap(keys->ports.src, keys->ports.dst);
823                 }
824                 break;
825         }
826 }
827
828 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
829 {
830         u32 hash;
831
832         __flow_hash_consistentify(keys);
833
834         hash = __flow_hash_words(flow_keys_hash_start(keys),
835                                  flow_keys_hash_length(keys), keyval);
836         if (!hash)
837                 hash = 1;
838
839         return hash;
840 }
841
842 u32 flow_hash_from_keys(struct flow_keys *keys)
843 {
844         __flow_hash_secret_init();
845         return __flow_hash_from_keys(keys, hashrnd);
846 }
847 EXPORT_SYMBOL(flow_hash_from_keys);
848
849 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
850                                   struct flow_keys *keys, u32 keyval)
851 {
852         skb_flow_dissect_flow_keys(skb, keys,
853                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
854
855         return __flow_hash_from_keys(keys, keyval);
856 }
857
858 struct _flow_keys_digest_data {
859         __be16  n_proto;
860         u8      ip_proto;
861         u8      padding;
862         __be32  ports;
863         __be32  src;
864         __be32  dst;
865 };
866
867 void make_flow_keys_digest(struct flow_keys_digest *digest,
868                            const struct flow_keys *flow)
869 {
870         struct _flow_keys_digest_data *data =
871             (struct _flow_keys_digest_data *)digest;
872
873         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
874
875         memset(digest, 0, sizeof(*digest));
876
877         data->n_proto = flow->basic.n_proto;
878         data->ip_proto = flow->basic.ip_proto;
879         data->ports = flow->ports.ports;
880         data->src = flow->addrs.v4addrs.src;
881         data->dst = flow->addrs.v4addrs.dst;
882 }
883 EXPORT_SYMBOL(make_flow_keys_digest);
884
885 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
886
887 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
888 {
889         struct flow_keys keys;
890
891         __flow_hash_secret_init();
892
893         memset(&keys, 0, sizeof(keys));
894         __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
895                            NULL, 0, 0, 0,
896                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
897
898         return __flow_hash_from_keys(&keys, hashrnd);
899 }
900 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
901
902 /**
903  * __skb_get_hash: calculate a flow hash
904  * @skb: sk_buff to calculate flow hash from
905  *
906  * This function calculates a flow hash based on src/dst addresses
907  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
908  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
909  * if hash is a canonical 4-tuple hash over transport ports.
910  */
911 void __skb_get_hash(struct sk_buff *skb)
912 {
913         struct flow_keys keys;
914         u32 hash;
915
916         __flow_hash_secret_init();
917
918         hash = ___skb_get_hash(skb, &keys, hashrnd);
919
920         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
921 }
922 EXPORT_SYMBOL(__skb_get_hash);
923
924 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
925 {
926         struct flow_keys keys;
927
928         return ___skb_get_hash(skb, &keys, perturb);
929 }
930 EXPORT_SYMBOL(skb_get_hash_perturb);
931
932 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
933 {
934         struct flow_keys keys;
935
936         memset(&keys, 0, sizeof(keys));
937
938         memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
939                sizeof(keys.addrs.v6addrs.src));
940         memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
941                sizeof(keys.addrs.v6addrs.dst));
942         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
943         keys.ports.src = fl6->fl6_sport;
944         keys.ports.dst = fl6->fl6_dport;
945         keys.keyid.keyid = fl6->fl6_gre_key;
946         keys.tags.flow_label = (__force u32)fl6->flowlabel;
947         keys.basic.ip_proto = fl6->flowi6_proto;
948
949         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
950                           flow_keys_have_l4(&keys));
951
952         return skb->hash;
953 }
954 EXPORT_SYMBOL(__skb_get_hash_flowi6);
955
956 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
957 {
958         struct flow_keys keys;
959
960         memset(&keys, 0, sizeof(keys));
961
962         keys.addrs.v4addrs.src = fl4->saddr;
963         keys.addrs.v4addrs.dst = fl4->daddr;
964         keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
965         keys.ports.src = fl4->fl4_sport;
966         keys.ports.dst = fl4->fl4_dport;
967         keys.keyid.keyid = fl4->fl4_gre_key;
968         keys.basic.ip_proto = fl4->flowi4_proto;
969
970         __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
971                           flow_keys_have_l4(&keys));
972
973         return skb->hash;
974 }
975 EXPORT_SYMBOL(__skb_get_hash_flowi4);
976
977 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
978                    const struct flow_keys *keys, int hlen)
979 {
980         u32 poff = keys->control.thoff;
981
982         /* skip L4 headers for fragments after the first */
983         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
984             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
985                 return poff;
986
987         switch (keys->basic.ip_proto) {
988         case IPPROTO_TCP: {
989                 /* access doff as u8 to avoid unaligned access */
990                 const u8 *doff;
991                 u8 _doff;
992
993                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
994                                             data, hlen, &_doff);
995                 if (!doff)
996                         return poff;
997
998                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
999                 break;
1000         }
1001         case IPPROTO_UDP:
1002         case IPPROTO_UDPLITE:
1003                 poff += sizeof(struct udphdr);
1004                 break;
1005         /* For the rest, we do not really care about header
1006          * extensions at this point for now.
1007          */
1008         case IPPROTO_ICMP:
1009                 poff += sizeof(struct icmphdr);
1010                 break;
1011         case IPPROTO_ICMPV6:
1012                 poff += sizeof(struct icmp6hdr);
1013                 break;
1014         case IPPROTO_IGMP:
1015                 poff += sizeof(struct igmphdr);
1016                 break;
1017         case IPPROTO_DCCP:
1018                 poff += sizeof(struct dccp_hdr);
1019                 break;
1020         case IPPROTO_SCTP:
1021                 poff += sizeof(struct sctphdr);
1022                 break;
1023         }
1024
1025         return poff;
1026 }
1027
1028 /**
1029  * skb_get_poff - get the offset to the payload
1030  * @skb: sk_buff to get the payload offset from
1031  *
1032  * The function will get the offset to the payload as far as it could
1033  * be dissected.  The main user is currently BPF, so that we can dynamically
1034  * truncate packets without needing to push actual payload to the user
1035  * space and can analyze headers only, instead.
1036  */
1037 u32 skb_get_poff(const struct sk_buff *skb)
1038 {
1039         struct flow_keys keys;
1040
1041         if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
1042                 return 0;
1043
1044         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1045 }
1046
1047 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1048 {
1049         memset(keys, 0, sizeof(*keys));
1050
1051         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1052             sizeof(keys->addrs.v6addrs.src));
1053         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1054             sizeof(keys->addrs.v6addrs.dst));
1055         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1056         keys->ports.src = fl6->fl6_sport;
1057         keys->ports.dst = fl6->fl6_dport;
1058         keys->keyid.keyid = fl6->fl6_gre_key;
1059         keys->tags.flow_label = (__force u32)fl6->flowlabel;
1060         keys->basic.ip_proto = fl6->flowi6_proto;
1061
1062         return flow_hash_from_keys(keys);
1063 }
1064 EXPORT_SYMBOL(__get_hash_from_flowi6);
1065
1066 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
1067 {
1068         memset(keys, 0, sizeof(*keys));
1069
1070         keys->addrs.v4addrs.src = fl4->saddr;
1071         keys->addrs.v4addrs.dst = fl4->daddr;
1072         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1073         keys->ports.src = fl4->fl4_sport;
1074         keys->ports.dst = fl4->fl4_dport;
1075         keys->keyid.keyid = fl4->fl4_gre_key;
1076         keys->basic.ip_proto = fl4->flowi4_proto;
1077
1078         return flow_hash_from_keys(keys);
1079 }
1080 EXPORT_SYMBOL(__get_hash_from_flowi4);
1081
1082 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1083         {
1084                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1085                 .offset = offsetof(struct flow_keys, control),
1086         },
1087         {
1088                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1089                 .offset = offsetof(struct flow_keys, basic),
1090         },
1091         {
1092                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1093                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1094         },
1095         {
1096                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1097                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1098         },
1099         {
1100                 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
1101                 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
1102         },
1103         {
1104                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1105                 .offset = offsetof(struct flow_keys, ports),
1106         },
1107         {
1108                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1109                 .offset = offsetof(struct flow_keys, vlan),
1110         },
1111         {
1112                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1113                 .offset = offsetof(struct flow_keys, tags),
1114         },
1115         {
1116                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1117                 .offset = offsetof(struct flow_keys, keyid),
1118         },
1119 };
1120
1121 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1122         {
1123                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1124                 .offset = offsetof(struct flow_keys, control),
1125         },
1126         {
1127                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1128                 .offset = offsetof(struct flow_keys, basic),
1129         },
1130         {
1131                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1132                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1133         },
1134         {
1135                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1136                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1137         },
1138         {
1139                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1140                 .offset = offsetof(struct flow_keys, ports),
1141         },
1142 };
1143
1144 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
1145         {
1146                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1147                 .offset = offsetof(struct flow_keys, control),
1148         },
1149         {
1150                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1151                 .offset = offsetof(struct flow_keys, basic),
1152         },
1153 };
1154
1155 struct flow_dissector flow_keys_dissector __read_mostly;
1156 EXPORT_SYMBOL(flow_keys_dissector);
1157
1158 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1159
1160 static int __init init_default_flow_dissectors(void)
1161 {
1162         skb_flow_dissector_init(&flow_keys_dissector,
1163                                 flow_keys_dissector_keys,
1164                                 ARRAY_SIZE(flow_keys_dissector_keys));
1165         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1166                                 flow_keys_dissector_symmetric_keys,
1167                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1168         skb_flow_dissector_init(&flow_keys_buf_dissector,
1169                                 flow_keys_buf_dissector_keys,
1170                                 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1171         return 0;
1172 }
1173
1174 core_initcall(init_default_flow_dissectors);