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TOMOYO Linux Cross Reference
Linux/net/ipv4/fou.c

Version: ~ [ linux-5.8-rc5 ] ~ [ linux-5.7.8 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.51 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.132 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.188 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.230 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.230 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ 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/module.h>
  2 #include <linux/errno.h>
  3 #include <linux/socket.h>
  4 #include <linux/skbuff.h>
  5 #include <linux/ip.h>
  6 #include <linux/udp.h>
  7 #include <linux/types.h>
  8 #include <linux/kernel.h>
  9 #include <net/genetlink.h>
 10 #include <net/gue.h>
 11 #include <net/fou.h>
 12 #include <net/ip.h>
 13 #include <net/protocol.h>
 14 #include <net/udp.h>
 15 #include <net/udp_tunnel.h>
 16 #include <net/xfrm.h>
 17 #include <uapi/linux/fou.h>
 18 #include <uapi/linux/genetlink.h>
 19 
 20 struct fou {
 21         struct socket *sock;
 22         u8 protocol;
 23         u8 flags;
 24         __be16 port;
 25         u8 family;
 26         u16 type;
 27         struct list_head list;
 28         struct rcu_head rcu;
 29 };
 30 
 31 #define FOU_F_REMCSUM_NOPARTIAL BIT(0)
 32 
 33 struct fou_cfg {
 34         u16 type;
 35         u8 protocol;
 36         u8 flags;
 37         struct udp_port_cfg udp_config;
 38 };
 39 
 40 static unsigned int fou_net_id;
 41 
 42 struct fou_net {
 43         struct list_head fou_list;
 44         struct mutex fou_lock;
 45 };
 46 
 47 static inline struct fou *fou_from_sock(struct sock *sk)
 48 {
 49         return sk->sk_user_data;
 50 }
 51 
 52 static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len)
 53 {
 54         /* Remove 'len' bytes from the packet (UDP header and
 55          * FOU header if present).
 56          */
 57         if (fou->family == AF_INET)
 58                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
 59         else
 60                 ipv6_hdr(skb)->payload_len =
 61                     htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
 62 
 63         __skb_pull(skb, len);
 64         skb_postpull_rcsum(skb, udp_hdr(skb), len);
 65         skb_reset_transport_header(skb);
 66         return iptunnel_pull_offloads(skb);
 67 }
 68 
 69 static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
 70 {
 71         struct fou *fou = fou_from_sock(sk);
 72 
 73         if (!fou)
 74                 return 1;
 75 
 76         if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
 77                 goto drop;
 78 
 79         return -fou->protocol;
 80 
 81 drop:
 82         kfree_skb(skb);
 83         return 0;
 84 }
 85 
 86 static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
 87                                   void *data, size_t hdrlen, u8 ipproto,
 88                                   bool nopartial)
 89 {
 90         __be16 *pd = data;
 91         size_t start = ntohs(pd[0]);
 92         size_t offset = ntohs(pd[1]);
 93         size_t plen = sizeof(struct udphdr) + hdrlen +
 94             max_t(size_t, offset + sizeof(u16), start);
 95 
 96         if (skb->remcsum_offload)
 97                 return guehdr;
 98 
 99         if (!pskb_may_pull(skb, plen))
100                 return NULL;
101         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
102 
103         skb_remcsum_process(skb, (void *)guehdr + hdrlen,
104                             start, offset, nopartial);
105 
106         return guehdr;
107 }
108 
109 static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
110 {
111         /* No support yet */
112         kfree_skb(skb);
113         return 0;
114 }
115 
116 static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
117 {
118         struct fou *fou = fou_from_sock(sk);
119         size_t len, optlen, hdrlen;
120         struct guehdr *guehdr;
121         void *data;
122         u16 doffset = 0;
123 
124         if (!fou)
125                 return 1;
126 
127         len = sizeof(struct udphdr) + sizeof(struct guehdr);
128         if (!pskb_may_pull(skb, len))
129                 goto drop;
130 
131         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
132 
133         switch (guehdr->version) {
134         case 0: /* Full GUE header present */
135                 break;
136 
137         case 1: {
138                 /* Direct encasulation of IPv4 or IPv6 */
139 
140                 int prot;
141 
142                 switch (((struct iphdr *)guehdr)->version) {
143                 case 4:
144                         prot = IPPROTO_IPIP;
145                         break;
146                 case 6:
147                         prot = IPPROTO_IPV6;
148                         break;
149                 default:
150                         goto drop;
151                 }
152 
153                 if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
154                         goto drop;
155 
156                 return -prot;
157         }
158 
159         default: /* Undefined version */
160                 goto drop;
161         }
162 
163         optlen = guehdr->hlen << 2;
164         len += optlen;
165 
166         if (!pskb_may_pull(skb, len))
167                 goto drop;
168 
169         /* guehdr may change after pull */
170         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
171 
172         hdrlen = sizeof(struct guehdr) + optlen;
173 
174         if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
175                 goto drop;
176 
177         hdrlen = sizeof(struct guehdr) + optlen;
178 
179         if (fou->family == AF_INET)
180                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
181         else
182                 ipv6_hdr(skb)->payload_len =
183                     htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
184 
185         /* Pull csum through the guehdr now . This can be used if
186          * there is a remote checksum offload.
187          */
188         skb_postpull_rcsum(skb, udp_hdr(skb), len);
189 
190         data = &guehdr[1];
191 
192         if (guehdr->flags & GUE_FLAG_PRIV) {
193                 __be32 flags = *(__be32 *)(data + doffset);
194 
195                 doffset += GUE_LEN_PRIV;
196 
197                 if (flags & GUE_PFLAG_REMCSUM) {
198                         guehdr = gue_remcsum(skb, guehdr, data + doffset,
199                                              hdrlen, guehdr->proto_ctype,
200                                              !!(fou->flags &
201                                                 FOU_F_REMCSUM_NOPARTIAL));
202                         if (!guehdr)
203                                 goto drop;
204 
205                         data = &guehdr[1];
206 
207                         doffset += GUE_PLEN_REMCSUM;
208                 }
209         }
210 
211         if (unlikely(guehdr->control))
212                 return gue_control_message(skb, guehdr);
213 
214         __skb_pull(skb, sizeof(struct udphdr) + hdrlen);
215         skb_reset_transport_header(skb);
216 
217         if (iptunnel_pull_offloads(skb))
218                 goto drop;
219 
220         return -guehdr->proto_ctype;
221 
222 drop:
223         kfree_skb(skb);
224         return 0;
225 }
226 
227 static struct sk_buff **fou_gro_receive(struct sock *sk,
228                                         struct sk_buff **head,
229                                         struct sk_buff *skb)
230 {
231         const struct net_offload *ops;
232         struct sk_buff **pp = NULL;
233         u8 proto = fou_from_sock(sk)->protocol;
234         const struct net_offload **offloads;
235 
236         /* We can clear the encap_mark for FOU as we are essentially doing
237          * one of two possible things.  We are either adding an L4 tunnel
238          * header to the outer L3 tunnel header, or we are are simply
239          * treating the GRE tunnel header as though it is a UDP protocol
240          * specific header such as VXLAN or GENEVE.
241          */
242         NAPI_GRO_CB(skb)->encap_mark = 0;
243 
244         /* Flag this frame as already having an outer encap header */
245         NAPI_GRO_CB(skb)->is_fou = 1;
246 
247         rcu_read_lock();
248         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
249         ops = rcu_dereference(offloads[proto]);
250         if (!ops || !ops->callbacks.gro_receive)
251                 goto out_unlock;
252 
253         pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
254 
255 out_unlock:
256         rcu_read_unlock();
257 
258         return pp;
259 }
260 
261 static int fou_gro_complete(struct sock *sk, struct sk_buff *skb,
262                             int nhoff)
263 {
264         const struct net_offload *ops;
265         u8 proto = fou_from_sock(sk)->protocol;
266         int err = -ENOSYS;
267         const struct net_offload **offloads;
268 
269         rcu_read_lock();
270         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
271         ops = rcu_dereference(offloads[proto]);
272         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
273                 goto out_unlock;
274 
275         err = ops->callbacks.gro_complete(skb, nhoff);
276 
277         skb_set_inner_mac_header(skb, nhoff);
278 
279 out_unlock:
280         rcu_read_unlock();
281 
282         return err;
283 }
284 
285 static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
286                                       struct guehdr *guehdr, void *data,
287                                       size_t hdrlen, struct gro_remcsum *grc,
288                                       bool nopartial)
289 {
290         __be16 *pd = data;
291         size_t start = ntohs(pd[0]);
292         size_t offset = ntohs(pd[1]);
293 
294         if (skb->remcsum_offload)
295                 return guehdr;
296 
297         if (!NAPI_GRO_CB(skb)->csum_valid)
298                 return NULL;
299 
300         guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen,
301                                          start, offset, grc, nopartial);
302 
303         skb->remcsum_offload = 1;
304 
305         return guehdr;
306 }
307 
308 static struct sk_buff **gue_gro_receive(struct sock *sk,
309                                         struct sk_buff **head,
310                                         struct sk_buff *skb)
311 {
312         const struct net_offload **offloads;
313         const struct net_offload *ops;
314         struct sk_buff **pp = NULL;
315         struct sk_buff *p;
316         struct guehdr *guehdr;
317         size_t len, optlen, hdrlen, off;
318         void *data;
319         u16 doffset = 0;
320         int flush = 1;
321         struct fou *fou = fou_from_sock(sk);
322         struct gro_remcsum grc;
323         u8 proto;
324 
325         skb_gro_remcsum_init(&grc);
326 
327         off = skb_gro_offset(skb);
328         len = off + sizeof(*guehdr);
329 
330         guehdr = skb_gro_header_fast(skb, off);
331         if (skb_gro_header_hard(skb, len)) {
332                 guehdr = skb_gro_header_slow(skb, len, off);
333                 if (unlikely(!guehdr))
334                         goto out;
335         }
336 
337         switch (guehdr->version) {
338         case 0:
339                 break;
340         case 1:
341                 switch (((struct iphdr *)guehdr)->version) {
342                 case 4:
343                         proto = IPPROTO_IPIP;
344                         break;
345                 case 6:
346                         proto = IPPROTO_IPV6;
347                         break;
348                 default:
349                         goto out;
350                 }
351                 goto next_proto;
352         default:
353                 goto out;
354         }
355 
356         optlen = guehdr->hlen << 2;
357         len += optlen;
358 
359         if (skb_gro_header_hard(skb, len)) {
360                 guehdr = skb_gro_header_slow(skb, len, off);
361                 if (unlikely(!guehdr))
362                         goto out;
363         }
364 
365         if (unlikely(guehdr->control) || guehdr->version != 0 ||
366             validate_gue_flags(guehdr, optlen))
367                 goto out;
368 
369         hdrlen = sizeof(*guehdr) + optlen;
370 
371         /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
372          * this is needed if there is a remote checkcsum offload.
373          */
374         skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
375 
376         data = &guehdr[1];
377 
378         if (guehdr->flags & GUE_FLAG_PRIV) {
379                 __be32 flags = *(__be32 *)(data + doffset);
380 
381                 doffset += GUE_LEN_PRIV;
382 
383                 if (flags & GUE_PFLAG_REMCSUM) {
384                         guehdr = gue_gro_remcsum(skb, off, guehdr,
385                                                  data + doffset, hdrlen, &grc,
386                                                  !!(fou->flags &
387                                                     FOU_F_REMCSUM_NOPARTIAL));
388 
389                         if (!guehdr)
390                                 goto out;
391 
392                         data = &guehdr[1];
393 
394                         doffset += GUE_PLEN_REMCSUM;
395                 }
396         }
397 
398         skb_gro_pull(skb, hdrlen);
399 
400         for (p = *head; p; p = p->next) {
401                 const struct guehdr *guehdr2;
402 
403                 if (!NAPI_GRO_CB(p)->same_flow)
404                         continue;
405 
406                 guehdr2 = (struct guehdr *)(p->data + off);
407 
408                 /* Compare base GUE header to be equal (covers
409                  * hlen, version, proto_ctype, and flags.
410                  */
411                 if (guehdr->word != guehdr2->word) {
412                         NAPI_GRO_CB(p)->same_flow = 0;
413                         continue;
414                 }
415 
416                 /* Compare optional fields are the same. */
417                 if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
418                                            guehdr->hlen << 2)) {
419                         NAPI_GRO_CB(p)->same_flow = 0;
420                         continue;
421                 }
422         }
423 
424         proto = guehdr->proto_ctype;
425 
426 next_proto:
427 
428         /* We can clear the encap_mark for GUE as we are essentially doing
429          * one of two possible things.  We are either adding an L4 tunnel
430          * header to the outer L3 tunnel header, or we are are simply
431          * treating the GRE tunnel header as though it is a UDP protocol
432          * specific header such as VXLAN or GENEVE.
433          */
434         NAPI_GRO_CB(skb)->encap_mark = 0;
435 
436         /* Flag this frame as already having an outer encap header */
437         NAPI_GRO_CB(skb)->is_fou = 1;
438 
439         rcu_read_lock();
440         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
441         ops = rcu_dereference(offloads[proto]);
442         if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
443                 goto out_unlock;
444 
445         pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
446         flush = 0;
447 
448 out_unlock:
449         rcu_read_unlock();
450 out:
451         skb_gro_flush_final_remcsum(skb, pp, flush, &grc);
452 
453         return pp;
454 }
455 
456 static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff)
457 {
458         const struct net_offload **offloads;
459         struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
460         const struct net_offload *ops;
461         unsigned int guehlen = 0;
462         u8 proto;
463         int err = -ENOENT;
464 
465         switch (guehdr->version) {
466         case 0:
467                 proto = guehdr->proto_ctype;
468                 guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
469                 break;
470         case 1:
471                 switch (((struct iphdr *)guehdr)->version) {
472                 case 4:
473                         proto = IPPROTO_IPIP;
474                         break;
475                 case 6:
476                         proto = IPPROTO_IPV6;
477                         break;
478                 default:
479                         return err;
480                 }
481                 break;
482         default:
483                 return err;
484         }
485 
486         rcu_read_lock();
487         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
488         ops = rcu_dereference(offloads[proto]);
489         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
490                 goto out_unlock;
491 
492         err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
493 
494         skb_set_inner_mac_header(skb, nhoff + guehlen);
495 
496 out_unlock:
497         rcu_read_unlock();
498         return err;
499 }
500 
501 static int fou_add_to_port_list(struct net *net, struct fou *fou)
502 {
503         struct fou_net *fn = net_generic(net, fou_net_id);
504         struct fou *fout;
505 
506         mutex_lock(&fn->fou_lock);
507         list_for_each_entry(fout, &fn->fou_list, list) {
508                 if (fou->port == fout->port &&
509                     fou->family == fout->family) {
510                         mutex_unlock(&fn->fou_lock);
511                         return -EALREADY;
512                 }
513         }
514 
515         list_add(&fou->list, &fn->fou_list);
516         mutex_unlock(&fn->fou_lock);
517 
518         return 0;
519 }
520 
521 static void fou_release(struct fou *fou)
522 {
523         struct socket *sock = fou->sock;
524 
525         list_del(&fou->list);
526         udp_tunnel_sock_release(sock);
527 
528         kfree_rcu(fou, rcu);
529 }
530 
531 static int fou_create(struct net *net, struct fou_cfg *cfg,
532                       struct socket **sockp)
533 {
534         struct socket *sock = NULL;
535         struct fou *fou = NULL;
536         struct sock *sk;
537         struct udp_tunnel_sock_cfg tunnel_cfg;
538         int err;
539 
540         /* Open UDP socket */
541         err = udp_sock_create(net, &cfg->udp_config, &sock);
542         if (err < 0)
543                 goto error;
544 
545         /* Allocate FOU port structure */
546         fou = kzalloc(sizeof(*fou), GFP_KERNEL);
547         if (!fou) {
548                 err = -ENOMEM;
549                 goto error;
550         }
551 
552         sk = sock->sk;
553 
554         fou->port = cfg->udp_config.local_udp_port;
555         fou->family = cfg->udp_config.family;
556         fou->flags = cfg->flags;
557         fou->type = cfg->type;
558         fou->sock = sock;
559 
560         memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
561         tunnel_cfg.encap_type = 1;
562         tunnel_cfg.sk_user_data = fou;
563         tunnel_cfg.encap_destroy = NULL;
564 
565         /* Initial for fou type */
566         switch (cfg->type) {
567         case FOU_ENCAP_DIRECT:
568                 tunnel_cfg.encap_rcv = fou_udp_recv;
569                 tunnel_cfg.gro_receive = fou_gro_receive;
570                 tunnel_cfg.gro_complete = fou_gro_complete;
571                 fou->protocol = cfg->protocol;
572                 break;
573         case FOU_ENCAP_GUE:
574                 tunnel_cfg.encap_rcv = gue_udp_recv;
575                 tunnel_cfg.gro_receive = gue_gro_receive;
576                 tunnel_cfg.gro_complete = gue_gro_complete;
577                 break;
578         default:
579                 err = -EINVAL;
580                 goto error;
581         }
582 
583         setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
584 
585         sk->sk_allocation = GFP_ATOMIC;
586 
587         err = fou_add_to_port_list(net, fou);
588         if (err)
589                 goto error;
590 
591         if (sockp)
592                 *sockp = sock;
593 
594         return 0;
595 
596 error:
597         kfree(fou);
598         if (sock)
599                 udp_tunnel_sock_release(sock);
600 
601         return err;
602 }
603 
604 static int fou_destroy(struct net *net, struct fou_cfg *cfg)
605 {
606         struct fou_net *fn = net_generic(net, fou_net_id);
607         __be16 port = cfg->udp_config.local_udp_port;
608         u8 family = cfg->udp_config.family;
609         int err = -EINVAL;
610         struct fou *fou;
611 
612         mutex_lock(&fn->fou_lock);
613         list_for_each_entry(fou, &fn->fou_list, list) {
614                 if (fou->port == port && fou->family == family) {
615                         fou_release(fou);
616                         err = 0;
617                         break;
618                 }
619         }
620         mutex_unlock(&fn->fou_lock);
621 
622         return err;
623 }
624 
625 static struct genl_family fou_nl_family;
626 
627 static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
628         [FOU_ATTR_PORT] = { .type = NLA_U16, },
629         [FOU_ATTR_AF] = { .type = NLA_U8, },
630         [FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
631         [FOU_ATTR_TYPE] = { .type = NLA_U8, },
632         [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
633 };
634 
635 static int parse_nl_config(struct genl_info *info,
636                            struct fou_cfg *cfg)
637 {
638         memset(cfg, 0, sizeof(*cfg));
639 
640         cfg->udp_config.family = AF_INET;
641 
642         if (info->attrs[FOU_ATTR_AF]) {
643                 u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
644 
645                 switch (family) {
646                 case AF_INET:
647                         break;
648                 case AF_INET6:
649                         cfg->udp_config.ipv6_v6only = 1;
650                         break;
651                 default:
652                         return -EAFNOSUPPORT;
653                 }
654 
655                 cfg->udp_config.family = family;
656         }
657 
658         if (info->attrs[FOU_ATTR_PORT]) {
659                 __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]);
660 
661                 cfg->udp_config.local_udp_port = port;
662         }
663 
664         if (info->attrs[FOU_ATTR_IPPROTO])
665                 cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
666 
667         if (info->attrs[FOU_ATTR_TYPE])
668                 cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
669 
670         if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
671                 cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
672 
673         return 0;
674 }
675 
676 static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
677 {
678         struct net *net = genl_info_net(info);
679         struct fou_cfg cfg;
680         int err;
681 
682         err = parse_nl_config(info, &cfg);
683         if (err)
684                 return err;
685 
686         return fou_create(net, &cfg, NULL);
687 }
688 
689 static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
690 {
691         struct net *net = genl_info_net(info);
692         struct fou_cfg cfg;
693         int err;
694 
695         err = parse_nl_config(info, &cfg);
696         if (err)
697                 return err;
698 
699         return fou_destroy(net, &cfg);
700 }
701 
702 static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
703 {
704         if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
705             nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
706             nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
707             nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
708                 return -1;
709 
710         if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
711                 if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
712                         return -1;
713         return 0;
714 }
715 
716 static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
717                          u32 flags, struct sk_buff *skb, u8 cmd)
718 {
719         void *hdr;
720 
721         hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
722         if (!hdr)
723                 return -ENOMEM;
724 
725         if (fou_fill_info(fou, skb) < 0)
726                 goto nla_put_failure;
727 
728         genlmsg_end(skb, hdr);
729         return 0;
730 
731 nla_put_failure:
732         genlmsg_cancel(skb, hdr);
733         return -EMSGSIZE;
734 }
735 
736 static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
737 {
738         struct net *net = genl_info_net(info);
739         struct fou_net *fn = net_generic(net, fou_net_id);
740         struct sk_buff *msg;
741         struct fou_cfg cfg;
742         struct fou *fout;
743         __be16 port;
744         u8 family;
745         int ret;
746 
747         ret = parse_nl_config(info, &cfg);
748         if (ret)
749                 return ret;
750         port = cfg.udp_config.local_udp_port;
751         if (port == 0)
752                 return -EINVAL;
753 
754         family = cfg.udp_config.family;
755         if (family != AF_INET && family != AF_INET6)
756                 return -EINVAL;
757 
758         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
759         if (!msg)
760                 return -ENOMEM;
761 
762         ret = -ESRCH;
763         mutex_lock(&fn->fou_lock);
764         list_for_each_entry(fout, &fn->fou_list, list) {
765                 if (port == fout->port && family == fout->family) {
766                         ret = fou_dump_info(fout, info->snd_portid,
767                                             info->snd_seq, 0, msg,
768                                             info->genlhdr->cmd);
769                         break;
770                 }
771         }
772         mutex_unlock(&fn->fou_lock);
773         if (ret < 0)
774                 goto out_free;
775 
776         return genlmsg_reply(msg, info);
777 
778 out_free:
779         nlmsg_free(msg);
780         return ret;
781 }
782 
783 static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
784 {
785         struct net *net = sock_net(skb->sk);
786         struct fou_net *fn = net_generic(net, fou_net_id);
787         struct fou *fout;
788         int idx = 0, ret;
789 
790         mutex_lock(&fn->fou_lock);
791         list_for_each_entry(fout, &fn->fou_list, list) {
792                 if (idx++ < cb->args[0])
793                         continue;
794                 ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
795                                     cb->nlh->nlmsg_seq, NLM_F_MULTI,
796                                     skb, FOU_CMD_GET);
797                 if (ret)
798                         break;
799         }
800         mutex_unlock(&fn->fou_lock);
801 
802         cb->args[0] = idx;
803         return skb->len;
804 }
805 
806 static const struct genl_ops fou_nl_ops[] = {
807         {
808                 .cmd = FOU_CMD_ADD,
809                 .doit = fou_nl_cmd_add_port,
810                 .policy = fou_nl_policy,
811                 .flags = GENL_ADMIN_PERM,
812         },
813         {
814                 .cmd = FOU_CMD_DEL,
815                 .doit = fou_nl_cmd_rm_port,
816                 .policy = fou_nl_policy,
817                 .flags = GENL_ADMIN_PERM,
818         },
819         {
820                 .cmd = FOU_CMD_GET,
821                 .doit = fou_nl_cmd_get_port,
822                 .dumpit = fou_nl_dump,
823                 .policy = fou_nl_policy,
824         },
825 };
826 
827 static struct genl_family fou_nl_family __ro_after_init = {
828         .hdrsize        = 0,
829         .name           = FOU_GENL_NAME,
830         .version        = FOU_GENL_VERSION,
831         .maxattr        = FOU_ATTR_MAX,
832         .netnsok        = true,
833         .module         = THIS_MODULE,
834         .ops            = fou_nl_ops,
835         .n_ops          = ARRAY_SIZE(fou_nl_ops),
836 };
837 
838 size_t fou_encap_hlen(struct ip_tunnel_encap *e)
839 {
840         return sizeof(struct udphdr);
841 }
842 EXPORT_SYMBOL(fou_encap_hlen);
843 
844 size_t gue_encap_hlen(struct ip_tunnel_encap *e)
845 {
846         size_t len;
847         bool need_priv = false;
848 
849         len = sizeof(struct udphdr) + sizeof(struct guehdr);
850 
851         if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
852                 len += GUE_PLEN_REMCSUM;
853                 need_priv = true;
854         }
855 
856         len += need_priv ? GUE_LEN_PRIV : 0;
857 
858         return len;
859 }
860 EXPORT_SYMBOL(gue_encap_hlen);
861 
862 int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
863                        u8 *protocol, __be16 *sport, int type)
864 {
865         int err;
866 
867         err = iptunnel_handle_offloads(skb, type);
868         if (err)
869                 return err;
870 
871         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
872                                                 skb, 0, 0, false);
873 
874         return 0;
875 }
876 EXPORT_SYMBOL(__fou_build_header);
877 
878 int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
879                        u8 *protocol, __be16 *sport, int type)
880 {
881         struct guehdr *guehdr;
882         size_t hdrlen, optlen = 0;
883         void *data;
884         bool need_priv = false;
885         int err;
886 
887         if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
888             skb->ip_summed == CHECKSUM_PARTIAL) {
889                 optlen += GUE_PLEN_REMCSUM;
890                 type |= SKB_GSO_TUNNEL_REMCSUM;
891                 need_priv = true;
892         }
893 
894         optlen += need_priv ? GUE_LEN_PRIV : 0;
895 
896         err = iptunnel_handle_offloads(skb, type);
897         if (err)
898                 return err;
899 
900         /* Get source port (based on flow hash) before skb_push */
901         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
902                                                 skb, 0, 0, false);
903 
904         hdrlen = sizeof(struct guehdr) + optlen;
905 
906         skb_push(skb, hdrlen);
907 
908         guehdr = (struct guehdr *)skb->data;
909 
910         guehdr->control = 0;
911         guehdr->version = 0;
912         guehdr->hlen = optlen >> 2;
913         guehdr->flags = 0;
914         guehdr->proto_ctype = *protocol;
915 
916         data = &guehdr[1];
917 
918         if (need_priv) {
919                 __be32 *flags = data;
920 
921                 guehdr->flags |= GUE_FLAG_PRIV;
922                 *flags = 0;
923                 data += GUE_LEN_PRIV;
924 
925                 if (type & SKB_GSO_TUNNEL_REMCSUM) {
926                         u16 csum_start = skb_checksum_start_offset(skb);
927                         __be16 *pd = data;
928 
929                         if (csum_start < hdrlen)
930                                 return -EINVAL;
931 
932                         csum_start -= hdrlen;
933                         pd[0] = htons(csum_start);
934                         pd[1] = htons(csum_start + skb->csum_offset);
935 
936                         if (!skb_is_gso(skb)) {
937                                 skb->ip_summed = CHECKSUM_NONE;
938                                 skb->encapsulation = 0;
939                         }
940 
941                         *flags |= GUE_PFLAG_REMCSUM;
942                         data += GUE_PLEN_REMCSUM;
943                 }
944 
945         }
946 
947         return 0;
948 }
949 EXPORT_SYMBOL(__gue_build_header);
950 
951 #ifdef CONFIG_NET_FOU_IP_TUNNELS
952 
953 static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
954                           struct flowi4 *fl4, u8 *protocol, __be16 sport)
955 {
956         struct udphdr *uh;
957 
958         skb_push(skb, sizeof(struct udphdr));
959         skb_reset_transport_header(skb);
960 
961         uh = udp_hdr(skb);
962 
963         uh->dest = e->dport;
964         uh->source = sport;
965         uh->len = htons(skb->len);
966         udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
967                      fl4->saddr, fl4->daddr, skb->len);
968 
969         *protocol = IPPROTO_UDP;
970 }
971 
972 static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
973                             u8 *protocol, struct flowi4 *fl4)
974 {
975         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
976                                                        SKB_GSO_UDP_TUNNEL;
977         __be16 sport;
978         int err;
979 
980         err = __fou_build_header(skb, e, protocol, &sport, type);
981         if (err)
982                 return err;
983 
984         fou_build_udp(skb, e, fl4, protocol, sport);
985 
986         return 0;
987 }
988 
989 static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
990                             u8 *protocol, struct flowi4 *fl4)
991 {
992         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
993                                                        SKB_GSO_UDP_TUNNEL;
994         __be16 sport;
995         int err;
996 
997         err = __gue_build_header(skb, e, protocol, &sport, type);
998         if (err)
999                 return err;
1000 
1001         fou_build_udp(skb, e, fl4, protocol, sport);
1002 
1003         return 0;
1004 }
1005 
1006 
1007 static const struct ip_tunnel_encap_ops fou_iptun_ops = {
1008         .encap_hlen = fou_encap_hlen,
1009         .build_header = fou_build_header,
1010 };
1011 
1012 static const struct ip_tunnel_encap_ops gue_iptun_ops = {
1013         .encap_hlen = gue_encap_hlen,
1014         .build_header = gue_build_header,
1015 };
1016 
1017 static int ip_tunnel_encap_add_fou_ops(void)
1018 {
1019         int ret;
1020 
1021         ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1022         if (ret < 0) {
1023                 pr_err("can't add fou ops\n");
1024                 return ret;
1025         }
1026 
1027         ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1028         if (ret < 0) {
1029                 pr_err("can't add gue ops\n");
1030                 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1031                 return ret;
1032         }
1033 
1034         return 0;
1035 }
1036 
1037 static void ip_tunnel_encap_del_fou_ops(void)
1038 {
1039         ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1040         ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1041 }
1042 
1043 #else
1044 
1045 static int ip_tunnel_encap_add_fou_ops(void)
1046 {
1047         return 0;
1048 }
1049 
1050 static void ip_tunnel_encap_del_fou_ops(void)
1051 {
1052 }
1053 
1054 #endif
1055 
1056 static __net_init int fou_init_net(struct net *net)
1057 {
1058         struct fou_net *fn = net_generic(net, fou_net_id);
1059 
1060         INIT_LIST_HEAD(&fn->fou_list);
1061         mutex_init(&fn->fou_lock);
1062         return 0;
1063 }
1064 
1065 static __net_exit void fou_exit_net(struct net *net)
1066 {
1067         struct fou_net *fn = net_generic(net, fou_net_id);
1068         struct fou *fou, *next;
1069 
1070         /* Close all the FOU sockets */
1071         mutex_lock(&fn->fou_lock);
1072         list_for_each_entry_safe(fou, next, &fn->fou_list, list)
1073                 fou_release(fou);
1074         mutex_unlock(&fn->fou_lock);
1075 }
1076 
1077 static struct pernet_operations fou_net_ops = {
1078         .init = fou_init_net,
1079         .exit = fou_exit_net,
1080         .id   = &fou_net_id,
1081         .size = sizeof(struct fou_net),
1082 };
1083 
1084 static int __init fou_init(void)
1085 {
1086         int ret;
1087 
1088         ret = register_pernet_device(&fou_net_ops);
1089         if (ret)
1090                 goto exit;
1091 
1092         ret = genl_register_family(&fou_nl_family);
1093         if (ret < 0)
1094                 goto unregister;
1095 
1096         ret = ip_tunnel_encap_add_fou_ops();
1097         if (ret == 0)
1098                 return 0;
1099 
1100         genl_unregister_family(&fou_nl_family);
1101 unregister:
1102         unregister_pernet_device(&fou_net_ops);
1103 exit:
1104         return ret;
1105 }
1106 
1107 static void __exit fou_fini(void)
1108 {
1109         ip_tunnel_encap_del_fou_ops();
1110         genl_unregister_family(&fou_nl_family);
1111         unregister_pernet_device(&fou_net_ops);
1112 }
1113 
1114 module_init(fou_init);
1115 module_exit(fou_fini);
1116 MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
1117 MODULE_LICENSE("GPL");
1118 

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