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Linux/net/openvswitch/actions.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * Copyright (c) 2007-2017 Nicira, Inc.
  4  */
  5 
  6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  7 
  8 #include <linux/skbuff.h>
  9 #include <linux/in.h>
 10 #include <linux/ip.h>
 11 #include <linux/openvswitch.h>
 12 #include <linux/netfilter_ipv6.h>
 13 #include <linux/sctp.h>
 14 #include <linux/tcp.h>
 15 #include <linux/udp.h>
 16 #include <linux/in6.h>
 17 #include <linux/if_arp.h>
 18 #include <linux/if_vlan.h>
 19 
 20 #include <net/dst.h>
 21 #include <net/ip.h>
 22 #include <net/ipv6.h>
 23 #include <net/ip6_fib.h>
 24 #include <net/checksum.h>
 25 #include <net/dsfield.h>
 26 #include <net/mpls.h>
 27 #include <net/sctp/checksum.h>
 28 
 29 #include "datapath.h"
 30 #include "flow.h"
 31 #include "conntrack.h"
 32 #include "vport.h"
 33 #include "flow_netlink.h"
 34 
 35 struct deferred_action {
 36         struct sk_buff *skb;
 37         const struct nlattr *actions;
 38         int actions_len;
 39 
 40         /* Store pkt_key clone when creating deferred action. */
 41         struct sw_flow_key pkt_key;
 42 };
 43 
 44 #define MAX_L2_LEN      (VLAN_ETH_HLEN + 3 * MPLS_HLEN)
 45 struct ovs_frag_data {
 46         unsigned long dst;
 47         struct vport *vport;
 48         struct ovs_skb_cb cb;
 49         __be16 inner_protocol;
 50         u16 network_offset;     /* valid only for MPLS */
 51         u16 vlan_tci;
 52         __be16 vlan_proto;
 53         unsigned int l2_len;
 54         u8 mac_proto;
 55         u8 l2_data[MAX_L2_LEN];
 56 };
 57 
 58 static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);
 59 
 60 #define DEFERRED_ACTION_FIFO_SIZE 10
 61 #define OVS_RECURSION_LIMIT 5
 62 #define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)
 63 struct action_fifo {
 64         int head;
 65         int tail;
 66         /* Deferred action fifo queue storage. */
 67         struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
 68 };
 69 
 70 struct action_flow_keys {
 71         struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
 72 };
 73 
 74 static struct action_fifo __percpu *action_fifos;
 75 static struct action_flow_keys __percpu *flow_keys;
 76 static DEFINE_PER_CPU(int, exec_actions_level);
 77 
 78 /* Make a clone of the 'key', using the pre-allocated percpu 'flow_keys'
 79  * space. Return NULL if out of key spaces.
 80  */
 81 static struct sw_flow_key *clone_key(const struct sw_flow_key *key_)
 82 {
 83         struct action_flow_keys *keys = this_cpu_ptr(flow_keys);
 84         int level = this_cpu_read(exec_actions_level);
 85         struct sw_flow_key *key = NULL;
 86 
 87         if (level <= OVS_DEFERRED_ACTION_THRESHOLD) {
 88                 key = &keys->key[level - 1];
 89                 *key = *key_;
 90         }
 91 
 92         return key;
 93 }
 94 
 95 static void action_fifo_init(struct action_fifo *fifo)
 96 {
 97         fifo->head = 0;
 98         fifo->tail = 0;
 99 }
100 
101 static bool action_fifo_is_empty(const struct action_fifo *fifo)
102 {
103         return (fifo->head == fifo->tail);
104 }
105 
106 static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
107 {
108         if (action_fifo_is_empty(fifo))
109                 return NULL;
110 
111         return &fifo->fifo[fifo->tail++];
112 }
113 
114 static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
115 {
116         if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
117                 return NULL;
118 
119         return &fifo->fifo[fifo->head++];
120 }
121 
122 /* Return true if fifo is not full */
123 static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
124                                     const struct sw_flow_key *key,
125                                     const struct nlattr *actions,
126                                     const int actions_len)
127 {
128         struct action_fifo *fifo;
129         struct deferred_action *da;
130 
131         fifo = this_cpu_ptr(action_fifos);
132         da = action_fifo_put(fifo);
133         if (da) {
134                 da->skb = skb;
135                 da->actions = actions;
136                 da->actions_len = actions_len;
137                 da->pkt_key = *key;
138         }
139 
140         return da;
141 }
142 
143 static void invalidate_flow_key(struct sw_flow_key *key)
144 {
145         key->mac_proto |= SW_FLOW_KEY_INVALID;
146 }
147 
148 static bool is_flow_key_valid(const struct sw_flow_key *key)
149 {
150         return !(key->mac_proto & SW_FLOW_KEY_INVALID);
151 }
152 
153 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
154                          struct sw_flow_key *key,
155                          u32 recirc_id,
156                          const struct nlattr *actions, int len,
157                          bool last, bool clone_flow_key);
158 
159 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
160                               struct sw_flow_key *key,
161                               const struct nlattr *attr, int len);
162 
163 static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
164                      __be32 mpls_lse, __be16 mpls_ethertype, __u16 mac_len)
165 {
166         int err;
167 
168         err = skb_mpls_push(skb, mpls_lse, mpls_ethertype, mac_len, !!mac_len);
169         if (err)
170                 return err;
171 
172         if (!mac_len)
173                 key->mac_proto = MAC_PROTO_NONE;
174 
175         invalidate_flow_key(key);
176         return 0;
177 }
178 
179 static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
180                     const __be16 ethertype)
181 {
182         int err;
183 
184         err = skb_mpls_pop(skb, ethertype, skb->mac_len,
185                            ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET);
186         if (err)
187                 return err;
188 
189         if (ethertype == htons(ETH_P_TEB))
190                 key->mac_proto = MAC_PROTO_ETHERNET;
191 
192         invalidate_flow_key(key);
193         return 0;
194 }
195 
196 static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
197                     const __be32 *mpls_lse, const __be32 *mask)
198 {
199         struct mpls_shim_hdr *stack;
200         __be32 lse;
201         int err;
202 
203         stack = mpls_hdr(skb);
204         lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
205         err = skb_mpls_update_lse(skb, lse);
206         if (err)
207                 return err;
208 
209         flow_key->mpls.lse[0] = lse;
210         return 0;
211 }
212 
213 static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
214 {
215         int err;
216 
217         err = skb_vlan_pop(skb);
218         if (skb_vlan_tag_present(skb)) {
219                 invalidate_flow_key(key);
220         } else {
221                 key->eth.vlan.tci = 0;
222                 key->eth.vlan.tpid = 0;
223         }
224         return err;
225 }
226 
227 static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
228                      const struct ovs_action_push_vlan *vlan)
229 {
230         if (skb_vlan_tag_present(skb)) {
231                 invalidate_flow_key(key);
232         } else {
233                 key->eth.vlan.tci = vlan->vlan_tci;
234                 key->eth.vlan.tpid = vlan->vlan_tpid;
235         }
236         return skb_vlan_push(skb, vlan->vlan_tpid,
237                              ntohs(vlan->vlan_tci) & ~VLAN_CFI_MASK);
238 }
239 
240 /* 'src' is already properly masked. */
241 static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
242 {
243         u16 *dst = (u16 *)dst_;
244         const u16 *src = (const u16 *)src_;
245         const u16 *mask = (const u16 *)mask_;
246 
247         OVS_SET_MASKED(dst[0], src[0], mask[0]);
248         OVS_SET_MASKED(dst[1], src[1], mask[1]);
249         OVS_SET_MASKED(dst[2], src[2], mask[2]);
250 }
251 
252 static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
253                         const struct ovs_key_ethernet *key,
254                         const struct ovs_key_ethernet *mask)
255 {
256         int err;
257 
258         err = skb_ensure_writable(skb, ETH_HLEN);
259         if (unlikely(err))
260                 return err;
261 
262         skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
263 
264         ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
265                                mask->eth_src);
266         ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
267                                mask->eth_dst);
268 
269         skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
270 
271         ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
272         ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
273         return 0;
274 }
275 
276 /* pop_eth does not support VLAN packets as this action is never called
277  * for them.
278  */
279 static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
280 {
281         skb_pull_rcsum(skb, ETH_HLEN);
282         skb_reset_mac_header(skb);
283         skb_reset_mac_len(skb);
284 
285         /* safe right before invalidate_flow_key */
286         key->mac_proto = MAC_PROTO_NONE;
287         invalidate_flow_key(key);
288         return 0;
289 }
290 
291 static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
292                     const struct ovs_action_push_eth *ethh)
293 {
294         struct ethhdr *hdr;
295 
296         /* Add the new Ethernet header */
297         if (skb_cow_head(skb, ETH_HLEN) < 0)
298                 return -ENOMEM;
299 
300         skb_push(skb, ETH_HLEN);
301         skb_reset_mac_header(skb);
302         skb_reset_mac_len(skb);
303 
304         hdr = eth_hdr(skb);
305         ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
306         ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
307         hdr->h_proto = skb->protocol;
308 
309         skb_postpush_rcsum(skb, hdr, ETH_HLEN);
310 
311         /* safe right before invalidate_flow_key */
312         key->mac_proto = MAC_PROTO_ETHERNET;
313         invalidate_flow_key(key);
314         return 0;
315 }
316 
317 static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key,
318                     const struct nshhdr *nh)
319 {
320         int err;
321 
322         err = nsh_push(skb, nh);
323         if (err)
324                 return err;
325 
326         /* safe right before invalidate_flow_key */
327         key->mac_proto = MAC_PROTO_NONE;
328         invalidate_flow_key(key);
329         return 0;
330 }
331 
332 static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key)
333 {
334         int err;
335 
336         err = nsh_pop(skb);
337         if (err)
338                 return err;
339 
340         /* safe right before invalidate_flow_key */
341         if (skb->protocol == htons(ETH_P_TEB))
342                 key->mac_proto = MAC_PROTO_ETHERNET;
343         else
344                 key->mac_proto = MAC_PROTO_NONE;
345         invalidate_flow_key(key);
346         return 0;
347 }
348 
349 static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
350                                   __be32 addr, __be32 new_addr)
351 {
352         int transport_len = skb->len - skb_transport_offset(skb);
353 
354         if (nh->frag_off & htons(IP_OFFSET))
355                 return;
356 
357         if (nh->protocol == IPPROTO_TCP) {
358                 if (likely(transport_len >= sizeof(struct tcphdr)))
359                         inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
360                                                  addr, new_addr, true);
361         } else if (nh->protocol == IPPROTO_UDP) {
362                 if (likely(transport_len >= sizeof(struct udphdr))) {
363                         struct udphdr *uh = udp_hdr(skb);
364 
365                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
366                                 inet_proto_csum_replace4(&uh->check, skb,
367                                                          addr, new_addr, true);
368                                 if (!uh->check)
369                                         uh->check = CSUM_MANGLED_0;
370                         }
371                 }
372         }
373 }
374 
375 static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
376                         __be32 *addr, __be32 new_addr)
377 {
378         update_ip_l4_checksum(skb, nh, *addr, new_addr);
379         csum_replace4(&nh->check, *addr, new_addr);
380         skb_clear_hash(skb);
381         *addr = new_addr;
382 }
383 
384 static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
385                                  __be32 addr[4], const __be32 new_addr[4])
386 {
387         int transport_len = skb->len - skb_transport_offset(skb);
388 
389         if (l4_proto == NEXTHDR_TCP) {
390                 if (likely(transport_len >= sizeof(struct tcphdr)))
391                         inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
392                                                   addr, new_addr, true);
393         } else if (l4_proto == NEXTHDR_UDP) {
394                 if (likely(transport_len >= sizeof(struct udphdr))) {
395                         struct udphdr *uh = udp_hdr(skb);
396 
397                         if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
398                                 inet_proto_csum_replace16(&uh->check, skb,
399                                                           addr, new_addr, true);
400                                 if (!uh->check)
401                                         uh->check = CSUM_MANGLED_0;
402                         }
403                 }
404         } else if (l4_proto == NEXTHDR_ICMP) {
405                 if (likely(transport_len >= sizeof(struct icmp6hdr)))
406                         inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
407                                                   skb, addr, new_addr, true);
408         }
409 }
410 
411 static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
412                            const __be32 mask[4], __be32 masked[4])
413 {
414         masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
415         masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
416         masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
417         masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
418 }
419 
420 static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
421                           __be32 addr[4], const __be32 new_addr[4],
422                           bool recalculate_csum)
423 {
424         if (recalculate_csum)
425                 update_ipv6_checksum(skb, l4_proto, addr, new_addr);
426 
427         skb_clear_hash(skb);
428         memcpy(addr, new_addr, sizeof(__be32[4]));
429 }
430 
431 static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
432 {
433         /* Bits 21-24 are always unmasked, so this retains their values. */
434         OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
435         OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
436         OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
437 }
438 
439 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
440                        u8 mask)
441 {
442         new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);
443 
444         csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
445         nh->ttl = new_ttl;
446 }
447 
448 static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
449                     const struct ovs_key_ipv4 *key,
450                     const struct ovs_key_ipv4 *mask)
451 {
452         struct iphdr *nh;
453         __be32 new_addr;
454         int err;
455 
456         err = skb_ensure_writable(skb, skb_network_offset(skb) +
457                                   sizeof(struct iphdr));
458         if (unlikely(err))
459                 return err;
460 
461         nh = ip_hdr(skb);
462 
463         /* Setting an IP addresses is typically only a side effect of
464          * matching on them in the current userspace implementation, so it
465          * makes sense to check if the value actually changed.
466          */
467         if (mask->ipv4_src) {
468                 new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);
469 
470                 if (unlikely(new_addr != nh->saddr)) {
471                         set_ip_addr(skb, nh, &nh->saddr, new_addr);
472                         flow_key->ipv4.addr.src = new_addr;
473                 }
474         }
475         if (mask->ipv4_dst) {
476                 new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);
477 
478                 if (unlikely(new_addr != nh->daddr)) {
479                         set_ip_addr(skb, nh, &nh->daddr, new_addr);
480                         flow_key->ipv4.addr.dst = new_addr;
481                 }
482         }
483         if (mask->ipv4_tos) {
484                 ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
485                 flow_key->ip.tos = nh->tos;
486         }
487         if (mask->ipv4_ttl) {
488                 set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
489                 flow_key->ip.ttl = nh->ttl;
490         }
491 
492         return 0;
493 }
494 
495 static bool is_ipv6_mask_nonzero(const __be32 addr[4])
496 {
497         return !!(addr[0] | addr[1] | addr[2] | addr[3]);
498 }
499 
500 static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
501                     const struct ovs_key_ipv6 *key,
502                     const struct ovs_key_ipv6 *mask)
503 {
504         struct ipv6hdr *nh;
505         int err;
506 
507         err = skb_ensure_writable(skb, skb_network_offset(skb) +
508                                   sizeof(struct ipv6hdr));
509         if (unlikely(err))
510                 return err;
511 
512         nh = ipv6_hdr(skb);
513 
514         /* Setting an IP addresses is typically only a side effect of
515          * matching on them in the current userspace implementation, so it
516          * makes sense to check if the value actually changed.
517          */
518         if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
519                 __be32 *saddr = (__be32 *)&nh->saddr;
520                 __be32 masked[4];
521 
522                 mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);
523 
524                 if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
525                         set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
526                                       true);
527                         memcpy(&flow_key->ipv6.addr.src, masked,
528                                sizeof(flow_key->ipv6.addr.src));
529                 }
530         }
531         if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
532                 unsigned int offset = 0;
533                 int flags = IP6_FH_F_SKIP_RH;
534                 bool recalc_csum = true;
535                 __be32 *daddr = (__be32 *)&nh->daddr;
536                 __be32 masked[4];
537 
538                 mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);
539 
540                 if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
541                         if (ipv6_ext_hdr(nh->nexthdr))
542                                 recalc_csum = (ipv6_find_hdr(skb, &offset,
543                                                              NEXTHDR_ROUTING,
544                                                              NULL, &flags)
545                                                != NEXTHDR_ROUTING);
546 
547                         set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
548                                       recalc_csum);
549                         memcpy(&flow_key->ipv6.addr.dst, masked,
550                                sizeof(flow_key->ipv6.addr.dst));
551                 }
552         }
553         if (mask->ipv6_tclass) {
554                 ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass);
555                 flow_key->ip.tos = ipv6_get_dsfield(nh);
556         }
557         if (mask->ipv6_label) {
558                 set_ipv6_fl(nh, ntohl(key->ipv6_label),
559                             ntohl(mask->ipv6_label));
560                 flow_key->ipv6.label =
561                     *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
562         }
563         if (mask->ipv6_hlimit) {
564                 OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit,
565                                mask->ipv6_hlimit);
566                 flow_key->ip.ttl = nh->hop_limit;
567         }
568         return 0;
569 }
570 
571 static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key,
572                    const struct nlattr *a)
573 {
574         struct nshhdr *nh;
575         size_t length;
576         int err;
577         u8 flags;
578         u8 ttl;
579         int i;
580 
581         struct ovs_key_nsh key;
582         struct ovs_key_nsh mask;
583 
584         err = nsh_key_from_nlattr(a, &key, &mask);
585         if (err)
586                 return err;
587 
588         /* Make sure the NSH base header is there */
589         if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN))
590                 return -ENOMEM;
591 
592         nh = nsh_hdr(skb);
593         length = nsh_hdr_len(nh);
594 
595         /* Make sure the whole NSH header is there */
596         err = skb_ensure_writable(skb, skb_network_offset(skb) +
597                                        length);
598         if (unlikely(err))
599                 return err;
600 
601         nh = nsh_hdr(skb);
602         skb_postpull_rcsum(skb, nh, length);
603         flags = nsh_get_flags(nh);
604         flags = OVS_MASKED(flags, key.base.flags, mask.base.flags);
605         flow_key->nsh.base.flags = flags;
606         ttl = nsh_get_ttl(nh);
607         ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl);
608         flow_key->nsh.base.ttl = ttl;
609         nsh_set_flags_and_ttl(nh, flags, ttl);
610         nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr,
611                                   mask.base.path_hdr);
612         flow_key->nsh.base.path_hdr = nh->path_hdr;
613         switch (nh->mdtype) {
614         case NSH_M_TYPE1:
615                 for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) {
616                         nh->md1.context[i] =
617                             OVS_MASKED(nh->md1.context[i], key.context[i],
618                                        mask.context[i]);
619                 }
620                 memcpy(flow_key->nsh.context, nh->md1.context,
621                        sizeof(nh->md1.context));
622                 break;
623         case NSH_M_TYPE2:
624                 memset(flow_key->nsh.context, 0,
625                        sizeof(flow_key->nsh.context));
626                 break;
627         default:
628                 return -EINVAL;
629         }
630         skb_postpush_rcsum(skb, nh, length);
631         return 0;
632 }
633 
634 /* Must follow skb_ensure_writable() since that can move the skb data. */
635 static void set_tp_port(struct sk_buff *skb, __be16 *port,
636                         __be16 new_port, __sum16 *check)
637 {
638         inet_proto_csum_replace2(check, skb, *port, new_port, false);
639         *port = new_port;
640 }
641 
642 static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key,
643                    const struct ovs_key_udp *key,
644                    const struct ovs_key_udp *mask)
645 {
646         struct udphdr *uh;
647         __be16 src, dst;
648         int err;
649 
650         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
651                                   sizeof(struct udphdr));
652         if (unlikely(err))
653                 return err;
654 
655         uh = udp_hdr(skb);
656         /* Either of the masks is non-zero, so do not bother checking them. */
657         src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src);
658         dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst);
659 
660         if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
661                 if (likely(src != uh->source)) {
662                         set_tp_port(skb, &uh->source, src, &uh->check);
663                         flow_key->tp.src = src;
664                 }
665                 if (likely(dst != uh->dest)) {
666                         set_tp_port(skb, &uh->dest, dst, &uh->check);
667                         flow_key->tp.dst = dst;
668                 }
669 
670                 if (unlikely(!uh->check))
671                         uh->check = CSUM_MANGLED_0;
672         } else {
673                 uh->source = src;
674                 uh->dest = dst;
675                 flow_key->tp.src = src;
676                 flow_key->tp.dst = dst;
677         }
678 
679         skb_clear_hash(skb);
680 
681         return 0;
682 }
683 
684 static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key,
685                    const struct ovs_key_tcp *key,
686                    const struct ovs_key_tcp *mask)
687 {
688         struct tcphdr *th;
689         __be16 src, dst;
690         int err;
691 
692         err = skb_ensure_writable(skb, skb_transport_offset(skb) +
693                                   sizeof(struct tcphdr));
694         if (unlikely(err))
695                 return err;
696 
697         th = tcp_hdr(skb);
698         src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src);
699         if (likely(src != th->source)) {
700                 set_tp_port(skb, &th->source, src, &th->check);
701                 flow_key->tp.src = src;
702         }
703         dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst);
704         if (likely(dst != th->dest)) {
705                 set_tp_port(skb, &th->dest, dst, &th->check);
706                 flow_key->tp.dst = dst;
707         }
708         skb_clear_hash(skb);
709 
710         return 0;
711 }
712 
713 static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key,
714                     const struct ovs_key_sctp *key,
715                     const struct ovs_key_sctp *mask)
716 {
717         unsigned int sctphoff = skb_transport_offset(skb);
718         struct sctphdr *sh;
719         __le32 old_correct_csum, new_csum, old_csum;
720         int err;
721 
722         err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr));
723         if (unlikely(err))
724                 return err;
725 
726         sh = sctp_hdr(skb);
727         old_csum = sh->checksum;
728         old_correct_csum = sctp_compute_cksum(skb, sctphoff);
729 
730         sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src);
731         sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst);
732 
733         new_csum = sctp_compute_cksum(skb, sctphoff);
734 
735         /* Carry any checksum errors through. */
736         sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
737 
738         skb_clear_hash(skb);
739         flow_key->tp.src = sh->source;
740         flow_key->tp.dst = sh->dest;
741 
742         return 0;
743 }
744 
745 static int ovs_vport_output(struct net *net, struct sock *sk, struct sk_buff *skb)
746 {
747         struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage);
748         struct vport *vport = data->vport;
749 
750         if (skb_cow_head(skb, data->l2_len) < 0) {
751                 kfree_skb(skb);
752                 return -ENOMEM;
753         }
754 
755         __skb_dst_copy(skb, data->dst);
756         *OVS_CB(skb) = data->cb;
757         skb->inner_protocol = data->inner_protocol;
758         if (data->vlan_tci & VLAN_CFI_MASK)
759                 __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci & ~VLAN_CFI_MASK);
760         else
761                 __vlan_hwaccel_clear_tag(skb);
762 
763         /* Reconstruct the MAC header.  */
764         skb_push(skb, data->l2_len);
765         memcpy(skb->data, &data->l2_data, data->l2_len);
766         skb_postpush_rcsum(skb, skb->data, data->l2_len);
767         skb_reset_mac_header(skb);
768 
769         if (eth_p_mpls(skb->protocol)) {
770                 skb->inner_network_header = skb->network_header;
771                 skb_set_network_header(skb, data->network_offset);
772                 skb_reset_mac_len(skb);
773         }
774 
775         ovs_vport_send(vport, skb, data->mac_proto);
776         return 0;
777 }
778 
779 static unsigned int
780 ovs_dst_get_mtu(const struct dst_entry *dst)
781 {
782         return dst->dev->mtu;
783 }
784 
785 static struct dst_ops ovs_dst_ops = {
786         .family = AF_UNSPEC,
787         .mtu = ovs_dst_get_mtu,
788 };
789 
790 /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is
791  * ovs_vport_output(), which is called once per fragmented packet.
792  */
793 static void prepare_frag(struct vport *vport, struct sk_buff *skb,
794                          u16 orig_network_offset, u8 mac_proto)
795 {
796         unsigned int hlen = skb_network_offset(skb);
797         struct ovs_frag_data *data;
798 
799         data = this_cpu_ptr(&ovs_frag_data_storage);
800         data->dst = skb->_skb_refdst;
801         data->vport = vport;
802         data->cb = *OVS_CB(skb);
803         data->inner_protocol = skb->inner_protocol;
804         data->network_offset = orig_network_offset;
805         if (skb_vlan_tag_present(skb))
806                 data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
807         else
808                 data->vlan_tci = 0;
809         data->vlan_proto = skb->vlan_proto;
810         data->mac_proto = mac_proto;
811         data->l2_len = hlen;
812         memcpy(&data->l2_data, skb->data, hlen);
813 
814         memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
815         skb_pull(skb, hlen);
816 }
817 
818 static void ovs_fragment(struct net *net, struct vport *vport,
819                          struct sk_buff *skb, u16 mru,
820                          struct sw_flow_key *key)
821 {
822         u16 orig_network_offset = 0;
823 
824         if (eth_p_mpls(skb->protocol)) {
825                 orig_network_offset = skb_network_offset(skb);
826                 skb->network_header = skb->inner_network_header;
827         }
828 
829         if (skb_network_offset(skb) > MAX_L2_LEN) {
830                 OVS_NLERR(1, "L2 header too long to fragment");
831                 goto err;
832         }
833 
834         if (key->eth.type == htons(ETH_P_IP)) {
835                 struct dst_entry ovs_dst;
836                 unsigned long orig_dst;
837 
838                 prepare_frag(vport, skb, orig_network_offset,
839                              ovs_key_mac_proto(key));
840                 dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1,
841                          DST_OBSOLETE_NONE, DST_NOCOUNT);
842                 ovs_dst.dev = vport->dev;
843 
844                 orig_dst = skb->_skb_refdst;
845                 skb_dst_set_noref(skb, &ovs_dst);
846                 IPCB(skb)->frag_max_size = mru;
847 
848                 ip_do_fragment(net, skb->sk, skb, ovs_vport_output);
849                 refdst_drop(orig_dst);
850         } else if (key->eth.type == htons(ETH_P_IPV6)) {
851                 const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
852                 unsigned long orig_dst;
853                 struct rt6_info ovs_rt;
854 
855                 if (!v6ops)
856                         goto err;
857 
858                 prepare_frag(vport, skb, orig_network_offset,
859                              ovs_key_mac_proto(key));
860                 memset(&ovs_rt, 0, sizeof(ovs_rt));
861                 dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1,
862                          DST_OBSOLETE_NONE, DST_NOCOUNT);
863                 ovs_rt.dst.dev = vport->dev;
864 
865                 orig_dst = skb->_skb_refdst;
866                 skb_dst_set_noref(skb, &ovs_rt.dst);
867                 IP6CB(skb)->frag_max_size = mru;
868 
869                 v6ops->fragment(net, skb->sk, skb, ovs_vport_output);
870                 refdst_drop(orig_dst);
871         } else {
872                 WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.",
873                           ovs_vport_name(vport), ntohs(key->eth.type), mru,
874                           vport->dev->mtu);
875                 goto err;
876         }
877 
878         return;
879 err:
880         kfree_skb(skb);
881 }
882 
883 static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port,
884                       struct sw_flow_key *key)
885 {
886         struct vport *vport = ovs_vport_rcu(dp, out_port);
887 
888         if (likely(vport)) {
889                 u16 mru = OVS_CB(skb)->mru;
890                 u32 cutlen = OVS_CB(skb)->cutlen;
891 
892                 if (unlikely(cutlen > 0)) {
893                         if (skb->len - cutlen > ovs_mac_header_len(key))
894                                 pskb_trim(skb, skb->len - cutlen);
895                         else
896                                 pskb_trim(skb, ovs_mac_header_len(key));
897                 }
898 
899                 if (likely(!mru ||
900                            (skb->len <= mru + vport->dev->hard_header_len))) {
901                         ovs_vport_send(vport, skb, ovs_key_mac_proto(key));
902                 } else if (mru <= vport->dev->mtu) {
903                         struct net *net = read_pnet(&dp->net);
904 
905                         ovs_fragment(net, vport, skb, mru, key);
906                 } else {
907                         kfree_skb(skb);
908                 }
909         } else {
910                 kfree_skb(skb);
911         }
912 }
913 
914 static int output_userspace(struct datapath *dp, struct sk_buff *skb,
915                             struct sw_flow_key *key, const struct nlattr *attr,
916                             const struct nlattr *actions, int actions_len,
917                             uint32_t cutlen)
918 {
919         struct dp_upcall_info upcall;
920         const struct nlattr *a;
921         int rem;
922 
923         memset(&upcall, 0, sizeof(upcall));
924         upcall.cmd = OVS_PACKET_CMD_ACTION;
925         upcall.mru = OVS_CB(skb)->mru;
926 
927         for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
928                  a = nla_next(a, &rem)) {
929                 switch (nla_type(a)) {
930                 case OVS_USERSPACE_ATTR_USERDATA:
931                         upcall.userdata = a;
932                         break;
933 
934                 case OVS_USERSPACE_ATTR_PID:
935                         upcall.portid = nla_get_u32(a);
936                         break;
937 
938                 case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: {
939                         /* Get out tunnel info. */
940                         struct vport *vport;
941 
942                         vport = ovs_vport_rcu(dp, nla_get_u32(a));
943                         if (vport) {
944                                 int err;
945 
946                                 err = dev_fill_metadata_dst(vport->dev, skb);
947                                 if (!err)
948                                         upcall.egress_tun_info = skb_tunnel_info(skb);
949                         }
950 
951                         break;
952                 }
953 
954                 case OVS_USERSPACE_ATTR_ACTIONS: {
955                         /* Include actions. */
956                         upcall.actions = actions;
957                         upcall.actions_len = actions_len;
958                         break;
959                 }
960 
961                 } /* End of switch. */
962         }
963 
964         return ovs_dp_upcall(dp, skb, key, &upcall, cutlen);
965 }
966 
967 static int dec_ttl_exception_handler(struct datapath *dp, struct sk_buff *skb,
968                                      struct sw_flow_key *key,
969                                      const struct nlattr *attr, bool last)
970 {
971         /* The first action is always 'OVS_DEC_TTL_ATTR_ARG'. */
972         struct nlattr *dec_ttl_arg = nla_data(attr);
973         int rem = nla_len(attr);
974 
975         if (nla_len(dec_ttl_arg)) {
976                 struct nlattr *actions = nla_next(dec_ttl_arg, &rem);
977 
978                 if (actions)
979                         return clone_execute(dp, skb, key, 0, actions, rem,
980                                              last, false);
981         }
982         consume_skb(skb);
983         return 0;
984 }
985 
986 /* When 'last' is true, sample() should always consume the 'skb'.
987  * Otherwise, sample() should keep 'skb' intact regardless what
988  * actions are executed within sample().
989  */
990 static int sample(struct datapath *dp, struct sk_buff *skb,
991                   struct sw_flow_key *key, const struct nlattr *attr,
992                   bool last)
993 {
994         struct nlattr *actions;
995         struct nlattr *sample_arg;
996         int rem = nla_len(attr);
997         const struct sample_arg *arg;
998         bool clone_flow_key;
999 
1000         /* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */
1001         sample_arg = nla_data(attr);
1002         arg = nla_data(sample_arg);
1003         actions = nla_next(sample_arg, &rem);
1004 
1005         if ((arg->probability != U32_MAX) &&
1006             (!arg->probability || prandom_u32() > arg->probability)) {
1007                 if (last)
1008                         consume_skb(skb);
1009                 return 0;
1010         }
1011 
1012         clone_flow_key = !arg->exec;
1013         return clone_execute(dp, skb, key, 0, actions, rem, last,
1014                              clone_flow_key);
1015 }
1016 
1017 /* When 'last' is true, clone() should always consume the 'skb'.
1018  * Otherwise, clone() should keep 'skb' intact regardless what
1019  * actions are executed within clone().
1020  */
1021 static int clone(struct datapath *dp, struct sk_buff *skb,
1022                  struct sw_flow_key *key, const struct nlattr *attr,
1023                  bool last)
1024 {
1025         struct nlattr *actions;
1026         struct nlattr *clone_arg;
1027         int rem = nla_len(attr);
1028         bool dont_clone_flow_key;
1029 
1030         /* The first action is always 'OVS_CLONE_ATTR_ARG'. */
1031         clone_arg = nla_data(attr);
1032         dont_clone_flow_key = nla_get_u32(clone_arg);
1033         actions = nla_next(clone_arg, &rem);
1034 
1035         return clone_execute(dp, skb, key, 0, actions, rem, last,
1036                              !dont_clone_flow_key);
1037 }
1038 
1039 static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key,
1040                          const struct nlattr *attr)
1041 {
1042         struct ovs_action_hash *hash_act = nla_data(attr);
1043         u32 hash = 0;
1044 
1045         /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
1046         hash = skb_get_hash(skb);
1047         hash = jhash_1word(hash, hash_act->hash_basis);
1048         if (!hash)
1049                 hash = 0x1;
1050 
1051         key->ovs_flow_hash = hash;
1052 }
1053 
1054 static int execute_set_action(struct sk_buff *skb,
1055                               struct sw_flow_key *flow_key,
1056                               const struct nlattr *a)
1057 {
1058         /* Only tunnel set execution is supported without a mask. */
1059         if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) {
1060                 struct ovs_tunnel_info *tun = nla_data(a);
1061 
1062                 skb_dst_drop(skb);
1063                 dst_hold((struct dst_entry *)tun->tun_dst);
1064                 skb_dst_set(skb, (struct dst_entry *)tun->tun_dst);
1065                 return 0;
1066         }
1067 
1068         return -EINVAL;
1069 }
1070 
1071 /* Mask is at the midpoint of the data. */
1072 #define get_mask(a, type) ((const type)nla_data(a) + 1)
1073 
1074 static int execute_masked_set_action(struct sk_buff *skb,
1075                                      struct sw_flow_key *flow_key,
1076                                      const struct nlattr *a)
1077 {
1078         int err = 0;
1079 
1080         switch (nla_type(a)) {
1081         case OVS_KEY_ATTR_PRIORITY:
1082                 OVS_SET_MASKED(skb->priority, nla_get_u32(a),
1083                                *get_mask(a, u32 *));
1084                 flow_key->phy.priority = skb->priority;
1085                 break;
1086 
1087         case OVS_KEY_ATTR_SKB_MARK:
1088                 OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *));
1089                 flow_key->phy.skb_mark = skb->mark;
1090                 break;
1091 
1092         case OVS_KEY_ATTR_TUNNEL_INFO:
1093                 /* Masked data not supported for tunnel. */
1094                 err = -EINVAL;
1095                 break;
1096 
1097         case OVS_KEY_ATTR_ETHERNET:
1098                 err = set_eth_addr(skb, flow_key, nla_data(a),
1099                                    get_mask(a, struct ovs_key_ethernet *));
1100                 break;
1101 
1102         case OVS_KEY_ATTR_NSH:
1103                 err = set_nsh(skb, flow_key, a);
1104                 break;
1105 
1106         case OVS_KEY_ATTR_IPV4:
1107                 err = set_ipv4(skb, flow_key, nla_data(a),
1108                                get_mask(a, struct ovs_key_ipv4 *));
1109                 break;
1110 
1111         case OVS_KEY_ATTR_IPV6:
1112                 err = set_ipv6(skb, flow_key, nla_data(a),
1113                                get_mask(a, struct ovs_key_ipv6 *));
1114                 break;
1115 
1116         case OVS_KEY_ATTR_TCP:
1117                 err = set_tcp(skb, flow_key, nla_data(a),
1118                               get_mask(a, struct ovs_key_tcp *));
1119                 break;
1120 
1121         case OVS_KEY_ATTR_UDP:
1122                 err = set_udp(skb, flow_key, nla_data(a),
1123                               get_mask(a, struct ovs_key_udp *));
1124                 break;
1125 
1126         case OVS_KEY_ATTR_SCTP:
1127                 err = set_sctp(skb, flow_key, nla_data(a),
1128                                get_mask(a, struct ovs_key_sctp *));
1129                 break;
1130 
1131         case OVS_KEY_ATTR_MPLS:
1132                 err = set_mpls(skb, flow_key, nla_data(a), get_mask(a,
1133                                                                     __be32 *));
1134                 break;
1135 
1136         case OVS_KEY_ATTR_CT_STATE:
1137         case OVS_KEY_ATTR_CT_ZONE:
1138         case OVS_KEY_ATTR_CT_MARK:
1139         case OVS_KEY_ATTR_CT_LABELS:
1140         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4:
1141         case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6:
1142                 err = -EINVAL;
1143                 break;
1144         }
1145 
1146         return err;
1147 }
1148 
1149 static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
1150                           struct sw_flow_key *key,
1151                           const struct nlattr *a, bool last)
1152 {
1153         u32 recirc_id;
1154 
1155         if (!is_flow_key_valid(key)) {
1156                 int err;
1157 
1158                 err = ovs_flow_key_update(skb, key);
1159                 if (err)
1160                         return err;
1161         }
1162         BUG_ON(!is_flow_key_valid(key));
1163 
1164         recirc_id = nla_get_u32(a);
1165         return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true);
1166 }
1167 
1168 static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb,
1169                                  struct sw_flow_key *key,
1170                                  const struct nlattr *attr, bool last)
1171 {
1172         struct ovs_skb_cb *ovs_cb = OVS_CB(skb);
1173         const struct nlattr *actions, *cpl_arg;
1174         int len, max_len, rem = nla_len(attr);
1175         const struct check_pkt_len_arg *arg;
1176         bool clone_flow_key;
1177 
1178         /* The first netlink attribute in 'attr' is always
1179          * 'OVS_CHECK_PKT_LEN_ATTR_ARG'.
1180          */
1181         cpl_arg = nla_data(attr);
1182         arg = nla_data(cpl_arg);
1183 
1184         len = ovs_cb->mru ? ovs_cb->mru + skb->mac_len : skb->len;
1185         max_len = arg->pkt_len;
1186 
1187         if ((skb_is_gso(skb) && skb_gso_validate_mac_len(skb, max_len)) ||
1188             len <= max_len) {
1189                 /* Second netlink attribute in 'attr' is always
1190                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
1191                  */
1192                 actions = nla_next(cpl_arg, &rem);
1193                 clone_flow_key = !arg->exec_for_lesser_equal;
1194         } else {
1195                 /* Third netlink attribute in 'attr' is always
1196                  * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'.
1197                  */
1198                 actions = nla_next(cpl_arg, &rem);
1199                 actions = nla_next(actions, &rem);
1200                 clone_flow_key = !arg->exec_for_greater;
1201         }
1202 
1203         return clone_execute(dp, skb, key, 0, nla_data(actions),
1204                              nla_len(actions), last, clone_flow_key);
1205 }
1206 
1207 static int execute_dec_ttl(struct sk_buff *skb, struct sw_flow_key *key)
1208 {
1209         int err;
1210 
1211         if (skb->protocol == htons(ETH_P_IPV6)) {
1212                 struct ipv6hdr *nh;
1213 
1214                 err = skb_ensure_writable(skb, skb_network_offset(skb) +
1215                                           sizeof(*nh));
1216                 if (unlikely(err))
1217                         return err;
1218 
1219                 nh = ipv6_hdr(skb);
1220 
1221                 if (nh->hop_limit <= 1)
1222                         return -EHOSTUNREACH;
1223 
1224                 key->ip.ttl = --nh->hop_limit;
1225         } else {
1226                 struct iphdr *nh;
1227                 u8 old_ttl;
1228 
1229                 err = skb_ensure_writable(skb, skb_network_offset(skb) +
1230                                           sizeof(*nh));
1231                 if (unlikely(err))
1232                         return err;
1233 
1234                 nh = ip_hdr(skb);
1235                 if (nh->ttl <= 1)
1236                         return -EHOSTUNREACH;
1237 
1238                 old_ttl = nh->ttl--;
1239                 csum_replace2(&nh->check, htons(old_ttl << 8),
1240                               htons(nh->ttl << 8));
1241                 key->ip.ttl = nh->ttl;
1242         }
1243         return 0;
1244 }
1245 
1246 /* Execute a list of actions against 'skb'. */
1247 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
1248                               struct sw_flow_key *key,
1249                               const struct nlattr *attr, int len)
1250 {
1251         const struct nlattr *a;
1252         int rem;
1253 
1254         for (a = attr, rem = len; rem > 0;
1255              a = nla_next(a, &rem)) {
1256                 int err = 0;
1257 
1258                 switch (nla_type(a)) {
1259                 case OVS_ACTION_ATTR_OUTPUT: {
1260                         int port = nla_get_u32(a);
1261                         struct sk_buff *clone;
1262 
1263                         /* Every output action needs a separate clone
1264                          * of 'skb', In case the output action is the
1265                          * last action, cloning can be avoided.
1266                          */
1267                         if (nla_is_last(a, rem)) {
1268                                 do_output(dp, skb, port, key);
1269                                 /* 'skb' has been used for output.
1270                                  */
1271                                 return 0;
1272                         }
1273 
1274                         clone = skb_clone(skb, GFP_ATOMIC);
1275                         if (clone)
1276                                 do_output(dp, clone, port, key);
1277                         OVS_CB(skb)->cutlen = 0;
1278                         break;
1279                 }
1280 
1281                 case OVS_ACTION_ATTR_TRUNC: {
1282                         struct ovs_action_trunc *trunc = nla_data(a);
1283 
1284                         if (skb->len > trunc->max_len)
1285                                 OVS_CB(skb)->cutlen = skb->len - trunc->max_len;
1286                         break;
1287                 }
1288 
1289                 case OVS_ACTION_ATTR_USERSPACE:
1290                         output_userspace(dp, skb, key, a, attr,
1291                                                      len, OVS_CB(skb)->cutlen);
1292                         OVS_CB(skb)->cutlen = 0;
1293                         break;
1294 
1295                 case OVS_ACTION_ATTR_HASH:
1296                         execute_hash(skb, key, a);
1297                         break;
1298 
1299                 case OVS_ACTION_ATTR_PUSH_MPLS: {
1300                         struct ovs_action_push_mpls *mpls = nla_data(a);
1301 
1302                         err = push_mpls(skb, key, mpls->mpls_lse,
1303                                         mpls->mpls_ethertype, skb->mac_len);
1304                         break;
1305                 }
1306                 case OVS_ACTION_ATTR_ADD_MPLS: {
1307                         struct ovs_action_add_mpls *mpls = nla_data(a);
1308                         __u16 mac_len = 0;
1309 
1310                         if (mpls->tun_flags & OVS_MPLS_L3_TUNNEL_FLAG_MASK)
1311                                 mac_len = skb->mac_len;
1312 
1313                         err = push_mpls(skb, key, mpls->mpls_lse,
1314                                         mpls->mpls_ethertype, mac_len);
1315                         break;
1316                 }
1317                 case OVS_ACTION_ATTR_POP_MPLS:
1318                         err = pop_mpls(skb, key, nla_get_be16(a));
1319                         break;
1320 
1321                 case OVS_ACTION_ATTR_PUSH_VLAN:
1322                         err = push_vlan(skb, key, nla_data(a));
1323                         break;
1324 
1325                 case OVS_ACTION_ATTR_POP_VLAN:
1326                         err = pop_vlan(skb, key);
1327                         break;
1328 
1329                 case OVS_ACTION_ATTR_RECIRC: {
1330                         bool last = nla_is_last(a, rem);
1331 
1332                         err = execute_recirc(dp, skb, key, a, last);
1333                         if (last) {
1334                                 /* If this is the last action, the skb has
1335                                  * been consumed or freed.
1336                                  * Return immediately.
1337                                  */
1338                                 return err;
1339                         }
1340                         break;
1341                 }
1342 
1343                 case OVS_ACTION_ATTR_SET:
1344                         err = execute_set_action(skb, key, nla_data(a));
1345                         break;
1346 
1347                 case OVS_ACTION_ATTR_SET_MASKED:
1348                 case OVS_ACTION_ATTR_SET_TO_MASKED:
1349                         err = execute_masked_set_action(skb, key, nla_data(a));
1350                         break;
1351 
1352                 case OVS_ACTION_ATTR_SAMPLE: {
1353                         bool last = nla_is_last(a, rem);
1354 
1355                         err = sample(dp, skb, key, a, last);
1356                         if (last)
1357                                 return err;
1358 
1359                         break;
1360                 }
1361 
1362                 case OVS_ACTION_ATTR_CT:
1363                         if (!is_flow_key_valid(key)) {
1364                                 err = ovs_flow_key_update(skb, key);
1365                                 if (err)
1366                                         return err;
1367                         }
1368 
1369                         err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key,
1370                                              nla_data(a));
1371 
1372                         /* Hide stolen IP fragments from user space. */
1373                         if (err)
1374                                 return err == -EINPROGRESS ? 0 : err;
1375                         break;
1376 
1377                 case OVS_ACTION_ATTR_CT_CLEAR:
1378                         err = ovs_ct_clear(skb, key);
1379                         break;
1380 
1381                 case OVS_ACTION_ATTR_PUSH_ETH:
1382                         err = push_eth(skb, key, nla_data(a));
1383                         break;
1384 
1385                 case OVS_ACTION_ATTR_POP_ETH:
1386                         err = pop_eth(skb, key);
1387                         break;
1388 
1389                 case OVS_ACTION_ATTR_PUSH_NSH: {
1390                         u8 buffer[NSH_HDR_MAX_LEN];
1391                         struct nshhdr *nh = (struct nshhdr *)buffer;
1392 
1393                         err = nsh_hdr_from_nlattr(nla_data(a), nh,
1394                                                   NSH_HDR_MAX_LEN);
1395                         if (unlikely(err))
1396                                 break;
1397                         err = push_nsh(skb, key, nh);
1398                         break;
1399                 }
1400 
1401                 case OVS_ACTION_ATTR_POP_NSH:
1402                         err = pop_nsh(skb, key);
1403                         break;
1404 
1405                 case OVS_ACTION_ATTR_METER:
1406                         if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) {
1407                                 consume_skb(skb);
1408                                 return 0;
1409                         }
1410                         break;
1411 
1412                 case OVS_ACTION_ATTR_CLONE: {
1413                         bool last = nla_is_last(a, rem);
1414 
1415                         err = clone(dp, skb, key, a, last);
1416                         if (last)
1417                                 return err;
1418 
1419                         break;
1420                 }
1421 
1422                 case OVS_ACTION_ATTR_CHECK_PKT_LEN: {
1423                         bool last = nla_is_last(a, rem);
1424 
1425                         err = execute_check_pkt_len(dp, skb, key, a, last);
1426                         if (last)
1427                                 return err;
1428 
1429                         break;
1430                 }
1431 
1432                 case OVS_ACTION_ATTR_DEC_TTL:
1433                         err = execute_dec_ttl(skb, key);
1434                         if (err == -EHOSTUNREACH) {
1435                                 err = dec_ttl_exception_handler(dp, skb, key,
1436                                                                 a, true);
1437                                 return err;
1438                         }
1439                         break;
1440                 }
1441 
1442                 if (unlikely(err)) {
1443                         kfree_skb(skb);
1444                         return err;
1445                 }
1446         }
1447 
1448         consume_skb(skb);
1449         return 0;
1450 }
1451 
1452 /* Execute the actions on the clone of the packet. The effect of the
1453  * execution does not affect the original 'skb' nor the original 'key'.
1454  *
1455  * The execution may be deferred in case the actions can not be executed
1456  * immediately.
1457  */
1458 static int clone_execute(struct datapath *dp, struct sk_buff *skb,
1459                          struct sw_flow_key *key, u32 recirc_id,
1460                          const struct nlattr *actions, int len,
1461                          bool last, bool clone_flow_key)
1462 {
1463         struct deferred_action *da;
1464         struct sw_flow_key *clone;
1465 
1466         skb = last ? skb : skb_clone(skb, GFP_ATOMIC);
1467         if (!skb) {
1468                 /* Out of memory, skip this action.
1469                  */
1470                 return 0;
1471         }
1472 
1473         /* When clone_flow_key is false, the 'key' will not be change
1474          * by the actions, then the 'key' can be used directly.
1475          * Otherwise, try to clone key from the next recursion level of
1476          * 'flow_keys'. If clone is successful, execute the actions
1477          * without deferring.
1478          */
1479         clone = clone_flow_key ? clone_key(key) : key;
1480         if (clone) {
1481                 int err = 0;
1482 
1483                 if (actions) { /* Sample action */
1484                         if (clone_flow_key)
1485                                 __this_cpu_inc(exec_actions_level);
1486 
1487                         err = do_execute_actions(dp, skb, clone,
1488                                                  actions, len);
1489 
1490                         if (clone_flow_key)
1491                                 __this_cpu_dec(exec_actions_level);
1492                 } else { /* Recirc action */
1493                         clone->recirc_id = recirc_id;
1494                         ovs_dp_process_packet(skb, clone);
1495                 }
1496                 return err;
1497         }
1498 
1499         /* Out of 'flow_keys' space. Defer actions */
1500         da = add_deferred_actions(skb, key, actions, len);
1501         if (da) {
1502                 if (!actions) { /* Recirc action */
1503                         key = &da->pkt_key;
1504                         key->recirc_id = recirc_id;
1505                 }
1506         } else {
1507                 /* Out of per CPU action FIFO space. Drop the 'skb' and
1508                  * log an error.
1509                  */
1510                 kfree_skb(skb);
1511 
1512                 if (net_ratelimit()) {
1513                         if (actions) { /* Sample action */
1514                                 pr_warn("%s: deferred action limit reached, drop sample action\n",
1515                                         ovs_dp_name(dp));
1516                         } else {  /* Recirc action */
1517                                 pr_warn("%s: deferred action limit reached, drop recirc action\n",
1518                                         ovs_dp_name(dp));
1519                         }
1520                 }
1521         }
1522         return 0;
1523 }
1524 
1525 static void process_deferred_actions(struct datapath *dp)
1526 {
1527         struct action_fifo *fifo = this_cpu_ptr(action_fifos);
1528 
1529         /* Do not touch the FIFO in case there is no deferred actions. */
1530         if (action_fifo_is_empty(fifo))
1531                 return;
1532 
1533         /* Finishing executing all deferred actions. */
1534         do {
1535                 struct deferred_action *da = action_fifo_get(fifo);
1536                 struct sk_buff *skb = da->skb;
1537                 struct sw_flow_key *key = &da->pkt_key;
1538                 const struct nlattr *actions = da->actions;
1539                 int actions_len = da->actions_len;
1540 
1541                 if (actions)
1542                         do_execute_actions(dp, skb, key, actions, actions_len);
1543                 else
1544                         ovs_dp_process_packet(skb, key);
1545         } while (!action_fifo_is_empty(fifo));
1546 
1547         /* Reset FIFO for the next packet.  */
1548         action_fifo_init(fifo);
1549 }
1550 
1551 /* Execute a list of actions against 'skb'. */
1552 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
1553                         const struct sw_flow_actions *acts,
1554                         struct sw_flow_key *key)
1555 {
1556         int err, level;
1557 
1558         level = __this_cpu_inc_return(exec_actions_level);
1559         if (unlikely(level > OVS_RECURSION_LIMIT)) {
1560                 net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n",
1561                                      ovs_dp_name(dp));
1562                 kfree_skb(skb);
1563                 err = -ENETDOWN;
1564                 goto out;
1565         }
1566 
1567         OVS_CB(skb)->acts_origlen = acts->orig_len;
1568         err = do_execute_actions(dp, skb, key,
1569                                  acts->actions, acts->actions_len);
1570 
1571         if (level == 1)
1572                 process_deferred_actions(dp);
1573 
1574 out:
1575         __this_cpu_dec(exec_actions_level);
1576         return err;
1577 }
1578 
1579 int action_fifos_init(void)
1580 {
1581         action_fifos = alloc_percpu(struct action_fifo);
1582         if (!action_fifos)
1583                 return -ENOMEM;
1584 
1585         flow_keys = alloc_percpu(struct action_flow_keys);
1586         if (!flow_keys) {
1587                 free_percpu(action_fifos);
1588                 return -ENOMEM;
1589         }
1590 
1591         return 0;
1592 }
1593 
1594 void action_fifos_exit(void)
1595 {
1596         free_percpu(action_fifos);
1597         free_percpu(flow_keys);
1598 }
1599 

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