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TOMOYO Linux Cross Reference
Linux/net/core/flow_dissector.c

Version: ~ [ linux-5.12-rc7 ] ~ [ linux-5.11.13 ] ~ [ linux-5.10.29 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.111 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.186 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.230 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.266 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.266 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

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

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