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

Version: ~ [ linux-5.10-rc1 ] ~ [ linux-5.9.1 ] ~ [ linux-5.8.16 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.72 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.152 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.202 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.240 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.240 ] ~ [ 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 ] ~
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  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         NAPI_GRO_CB(skb)->flush |= flush;
452         skb_gro_remcsum_cleanup(skb, &grc);
453         skb->remcsum_offload = 0;
454 
455         return pp;
456 }
457 
458 static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff)
459 {
460         const struct net_offload **offloads;
461         struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
462         const struct net_offload *ops;
463         unsigned int guehlen = 0;
464         u8 proto;
465         int err = -ENOENT;
466 
467         switch (guehdr->version) {
468         case 0:
469                 proto = guehdr->proto_ctype;
470                 guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
471                 break;
472         case 1:
473                 switch (((struct iphdr *)guehdr)->version) {
474                 case 4:
475                         proto = IPPROTO_IPIP;
476                         break;
477                 case 6:
478                         proto = IPPROTO_IPV6;
479                         break;
480                 default:
481                         return err;
482                 }
483                 break;
484         default:
485                 return err;
486         }
487 
488         rcu_read_lock();
489         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
490         ops = rcu_dereference(offloads[proto]);
491         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
492                 goto out_unlock;
493 
494         err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
495 
496         skb_set_inner_mac_header(skb, nhoff + guehlen);
497 
498 out_unlock:
499         rcu_read_unlock();
500         return err;
501 }
502 
503 static int fou_add_to_port_list(struct net *net, struct fou *fou)
504 {
505         struct fou_net *fn = net_generic(net, fou_net_id);
506         struct fou *fout;
507 
508         mutex_lock(&fn->fou_lock);
509         list_for_each_entry(fout, &fn->fou_list, list) {
510                 if (fou->port == fout->port &&
511                     fou->family == fout->family) {
512                         mutex_unlock(&fn->fou_lock);
513                         return -EALREADY;
514                 }
515         }
516 
517         list_add(&fou->list, &fn->fou_list);
518         mutex_unlock(&fn->fou_lock);
519 
520         return 0;
521 }
522 
523 static void fou_release(struct fou *fou)
524 {
525         struct socket *sock = fou->sock;
526 
527         list_del(&fou->list);
528         udp_tunnel_sock_release(sock);
529 
530         kfree_rcu(fou, rcu);
531 }
532 
533 static int fou_create(struct net *net, struct fou_cfg *cfg,
534                       struct socket **sockp)
535 {
536         struct socket *sock = NULL;
537         struct fou *fou = NULL;
538         struct sock *sk;
539         struct udp_tunnel_sock_cfg tunnel_cfg;
540         int err;
541 
542         /* Open UDP socket */
543         err = udp_sock_create(net, &cfg->udp_config, &sock);
544         if (err < 0)
545                 goto error;
546 
547         /* Allocate FOU port structure */
548         fou = kzalloc(sizeof(*fou), GFP_KERNEL);
549         if (!fou) {
550                 err = -ENOMEM;
551                 goto error;
552         }
553 
554         sk = sock->sk;
555 
556         fou->port = cfg->udp_config.local_udp_port;
557         fou->family = cfg->udp_config.family;
558         fou->flags = cfg->flags;
559         fou->type = cfg->type;
560         fou->sock = sock;
561 
562         memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
563         tunnel_cfg.encap_type = 1;
564         tunnel_cfg.sk_user_data = fou;
565         tunnel_cfg.encap_destroy = NULL;
566 
567         /* Initial for fou type */
568         switch (cfg->type) {
569         case FOU_ENCAP_DIRECT:
570                 tunnel_cfg.encap_rcv = fou_udp_recv;
571                 tunnel_cfg.gro_receive = fou_gro_receive;
572                 tunnel_cfg.gro_complete = fou_gro_complete;
573                 fou->protocol = cfg->protocol;
574                 break;
575         case FOU_ENCAP_GUE:
576                 tunnel_cfg.encap_rcv = gue_udp_recv;
577                 tunnel_cfg.gro_receive = gue_gro_receive;
578                 tunnel_cfg.gro_complete = gue_gro_complete;
579                 break;
580         default:
581                 err = -EINVAL;
582                 goto error;
583         }
584 
585         setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
586 
587         sk->sk_allocation = GFP_ATOMIC;
588 
589         err = fou_add_to_port_list(net, fou);
590         if (err)
591                 goto error;
592 
593         if (sockp)
594                 *sockp = sock;
595 
596         return 0;
597 
598 error:
599         kfree(fou);
600         if (sock)
601                 udp_tunnel_sock_release(sock);
602 
603         return err;
604 }
605 
606 static int fou_destroy(struct net *net, struct fou_cfg *cfg)
607 {
608         struct fou_net *fn = net_generic(net, fou_net_id);
609         __be16 port = cfg->udp_config.local_udp_port;
610         u8 family = cfg->udp_config.family;
611         int err = -EINVAL;
612         struct fou *fou;
613 
614         mutex_lock(&fn->fou_lock);
615         list_for_each_entry(fou, &fn->fou_list, list) {
616                 if (fou->port == port && fou->family == family) {
617                         fou_release(fou);
618                         err = 0;
619                         break;
620                 }
621         }
622         mutex_unlock(&fn->fou_lock);
623 
624         return err;
625 }
626 
627 static struct genl_family fou_nl_family;
628 
629 static const struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
630         [FOU_ATTR_PORT] = { .type = NLA_U16, },
631         [FOU_ATTR_AF] = { .type = NLA_U8, },
632         [FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
633         [FOU_ATTR_TYPE] = { .type = NLA_U8, },
634         [FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
635 };
636 
637 static int parse_nl_config(struct genl_info *info,
638                            struct fou_cfg *cfg)
639 {
640         memset(cfg, 0, sizeof(*cfg));
641 
642         cfg->udp_config.family = AF_INET;
643 
644         if (info->attrs[FOU_ATTR_AF]) {
645                 u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
646 
647                 switch (family) {
648                 case AF_INET:
649                         break;
650                 case AF_INET6:
651                         cfg->udp_config.ipv6_v6only = 1;
652                         break;
653                 default:
654                         return -EAFNOSUPPORT;
655                 }
656 
657                 cfg->udp_config.family = family;
658         }
659 
660         if (info->attrs[FOU_ATTR_PORT]) {
661                 __be16 port = nla_get_be16(info->attrs[FOU_ATTR_PORT]);
662 
663                 cfg->udp_config.local_udp_port = port;
664         }
665 
666         if (info->attrs[FOU_ATTR_IPPROTO])
667                 cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
668 
669         if (info->attrs[FOU_ATTR_TYPE])
670                 cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
671 
672         if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
673                 cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
674 
675         return 0;
676 }
677 
678 static int fou_nl_cmd_add_port(struct sk_buff *skb, struct genl_info *info)
679 {
680         struct net *net = genl_info_net(info);
681         struct fou_cfg cfg;
682         int err;
683 
684         err = parse_nl_config(info, &cfg);
685         if (err)
686                 return err;
687 
688         return fou_create(net, &cfg, NULL);
689 }
690 
691 static int fou_nl_cmd_rm_port(struct sk_buff *skb, struct genl_info *info)
692 {
693         struct net *net = genl_info_net(info);
694         struct fou_cfg cfg;
695         int err;
696 
697         err = parse_nl_config(info, &cfg);
698         if (err)
699                 return err;
700 
701         return fou_destroy(net, &cfg);
702 }
703 
704 static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
705 {
706         if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
707             nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
708             nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
709             nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
710                 return -1;
711 
712         if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
713                 if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
714                         return -1;
715         return 0;
716 }
717 
718 static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
719                          u32 flags, struct sk_buff *skb, u8 cmd)
720 {
721         void *hdr;
722 
723         hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
724         if (!hdr)
725                 return -ENOMEM;
726 
727         if (fou_fill_info(fou, skb) < 0)
728                 goto nla_put_failure;
729 
730         genlmsg_end(skb, hdr);
731         return 0;
732 
733 nla_put_failure:
734         genlmsg_cancel(skb, hdr);
735         return -EMSGSIZE;
736 }
737 
738 static int fou_nl_cmd_get_port(struct sk_buff *skb, struct genl_info *info)
739 {
740         struct net *net = genl_info_net(info);
741         struct fou_net *fn = net_generic(net, fou_net_id);
742         struct sk_buff *msg;
743         struct fou_cfg cfg;
744         struct fou *fout;
745         __be16 port;
746         u8 family;
747         int ret;
748 
749         ret = parse_nl_config(info, &cfg);
750         if (ret)
751                 return ret;
752         port = cfg.udp_config.local_udp_port;
753         if (port == 0)
754                 return -EINVAL;
755 
756         family = cfg.udp_config.family;
757         if (family != AF_INET && family != AF_INET6)
758                 return -EINVAL;
759 
760         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
761         if (!msg)
762                 return -ENOMEM;
763 
764         ret = -ESRCH;
765         mutex_lock(&fn->fou_lock);
766         list_for_each_entry(fout, &fn->fou_list, list) {
767                 if (port == fout->port && family == fout->family) {
768                         ret = fou_dump_info(fout, info->snd_portid,
769                                             info->snd_seq, 0, msg,
770                                             info->genlhdr->cmd);
771                         break;
772                 }
773         }
774         mutex_unlock(&fn->fou_lock);
775         if (ret < 0)
776                 goto out_free;
777 
778         return genlmsg_reply(msg, info);
779 
780 out_free:
781         nlmsg_free(msg);
782         return ret;
783 }
784 
785 static int fou_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
786 {
787         struct net *net = sock_net(skb->sk);
788         struct fou_net *fn = net_generic(net, fou_net_id);
789         struct fou *fout;
790         int idx = 0, ret;
791 
792         mutex_lock(&fn->fou_lock);
793         list_for_each_entry(fout, &fn->fou_list, list) {
794                 if (idx++ < cb->args[0])
795                         continue;
796                 ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
797                                     cb->nlh->nlmsg_seq, NLM_F_MULTI,
798                                     skb, FOU_CMD_GET);
799                 if (ret)
800                         break;
801         }
802         mutex_unlock(&fn->fou_lock);
803 
804         cb->args[0] = idx;
805         return skb->len;
806 }
807 
808 static const struct genl_ops fou_nl_ops[] = {
809         {
810                 .cmd = FOU_CMD_ADD,
811                 .doit = fou_nl_cmd_add_port,
812                 .policy = fou_nl_policy,
813                 .flags = GENL_ADMIN_PERM,
814         },
815         {
816                 .cmd = FOU_CMD_DEL,
817                 .doit = fou_nl_cmd_rm_port,
818                 .policy = fou_nl_policy,
819                 .flags = GENL_ADMIN_PERM,
820         },
821         {
822                 .cmd = FOU_CMD_GET,
823                 .doit = fou_nl_cmd_get_port,
824                 .dumpit = fou_nl_dump,
825                 .policy = fou_nl_policy,
826         },
827 };
828 
829 static struct genl_family fou_nl_family __ro_after_init = {
830         .hdrsize        = 0,
831         .name           = FOU_GENL_NAME,
832         .version        = FOU_GENL_VERSION,
833         .maxattr        = FOU_ATTR_MAX,
834         .netnsok        = true,
835         .module         = THIS_MODULE,
836         .ops            = fou_nl_ops,
837         .n_ops          = ARRAY_SIZE(fou_nl_ops),
838 };
839 
840 size_t fou_encap_hlen(struct ip_tunnel_encap *e)
841 {
842         return sizeof(struct udphdr);
843 }
844 EXPORT_SYMBOL(fou_encap_hlen);
845 
846 size_t gue_encap_hlen(struct ip_tunnel_encap *e)
847 {
848         size_t len;
849         bool need_priv = false;
850 
851         len = sizeof(struct udphdr) + sizeof(struct guehdr);
852 
853         if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
854                 len += GUE_PLEN_REMCSUM;
855                 need_priv = true;
856         }
857 
858         len += need_priv ? GUE_LEN_PRIV : 0;
859 
860         return len;
861 }
862 EXPORT_SYMBOL(gue_encap_hlen);
863 
864 int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
865                        u8 *protocol, __be16 *sport, int type)
866 {
867         int err;
868 
869         err = iptunnel_handle_offloads(skb, type);
870         if (err)
871                 return err;
872 
873         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
874                                                 skb, 0, 0, false);
875 
876         return 0;
877 }
878 EXPORT_SYMBOL(__fou_build_header);
879 
880 int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
881                        u8 *protocol, __be16 *sport, int type)
882 {
883         struct guehdr *guehdr;
884         size_t hdrlen, optlen = 0;
885         void *data;
886         bool need_priv = false;
887         int err;
888 
889         if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
890             skb->ip_summed == CHECKSUM_PARTIAL) {
891                 optlen += GUE_PLEN_REMCSUM;
892                 type |= SKB_GSO_TUNNEL_REMCSUM;
893                 need_priv = true;
894         }
895 
896         optlen += need_priv ? GUE_LEN_PRIV : 0;
897 
898         err = iptunnel_handle_offloads(skb, type);
899         if (err)
900                 return err;
901 
902         /* Get source port (based on flow hash) before skb_push */
903         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
904                                                 skb, 0, 0, false);
905 
906         hdrlen = sizeof(struct guehdr) + optlen;
907 
908         skb_push(skb, hdrlen);
909 
910         guehdr = (struct guehdr *)skb->data;
911 
912         guehdr->control = 0;
913         guehdr->version = 0;
914         guehdr->hlen = optlen >> 2;
915         guehdr->flags = 0;
916         guehdr->proto_ctype = *protocol;
917 
918         data = &guehdr[1];
919 
920         if (need_priv) {
921                 __be32 *flags = data;
922 
923                 guehdr->flags |= GUE_FLAG_PRIV;
924                 *flags = 0;
925                 data += GUE_LEN_PRIV;
926 
927                 if (type & SKB_GSO_TUNNEL_REMCSUM) {
928                         u16 csum_start = skb_checksum_start_offset(skb);
929                         __be16 *pd = data;
930 
931                         if (csum_start < hdrlen)
932                                 return -EINVAL;
933 
934                         csum_start -= hdrlen;
935                         pd[0] = htons(csum_start);
936                         pd[1] = htons(csum_start + skb->csum_offset);
937 
938                         if (!skb_is_gso(skb)) {
939                                 skb->ip_summed = CHECKSUM_NONE;
940                                 skb->encapsulation = 0;
941                         }
942 
943                         *flags |= GUE_PFLAG_REMCSUM;
944                         data += GUE_PLEN_REMCSUM;
945                 }
946 
947         }
948 
949         return 0;
950 }
951 EXPORT_SYMBOL(__gue_build_header);
952 
953 #ifdef CONFIG_NET_FOU_IP_TUNNELS
954 
955 static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
956                           struct flowi4 *fl4, u8 *protocol, __be16 sport)
957 {
958         struct udphdr *uh;
959 
960         skb_push(skb, sizeof(struct udphdr));
961         skb_reset_transport_header(skb);
962 
963         uh = udp_hdr(skb);
964 
965         uh->dest = e->dport;
966         uh->source = sport;
967         uh->len = htons(skb->len);
968         udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
969                      fl4->saddr, fl4->daddr, skb->len);
970 
971         *protocol = IPPROTO_UDP;
972 }
973 
974 static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
975                             u8 *protocol, struct flowi4 *fl4)
976 {
977         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
978                                                        SKB_GSO_UDP_TUNNEL;
979         __be16 sport;
980         int err;
981 
982         err = __fou_build_header(skb, e, protocol, &sport, type);
983         if (err)
984                 return err;
985 
986         fou_build_udp(skb, e, fl4, protocol, sport);
987 
988         return 0;
989 }
990 
991 static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
992                             u8 *protocol, struct flowi4 *fl4)
993 {
994         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
995                                                        SKB_GSO_UDP_TUNNEL;
996         __be16 sport;
997         int err;
998 
999         err = __gue_build_header(skb, e, protocol, &sport, type);
1000         if (err)
1001                 return err;
1002 
1003         fou_build_udp(skb, e, fl4, protocol, sport);
1004 
1005         return 0;
1006 }
1007 
1008 
1009 static const struct ip_tunnel_encap_ops fou_iptun_ops = {
1010         .encap_hlen = fou_encap_hlen,
1011         .build_header = fou_build_header,
1012 };
1013 
1014 static const struct ip_tunnel_encap_ops gue_iptun_ops = {
1015         .encap_hlen = gue_encap_hlen,
1016         .build_header = gue_build_header,
1017 };
1018 
1019 static int ip_tunnel_encap_add_fou_ops(void)
1020 {
1021         int ret;
1022 
1023         ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1024         if (ret < 0) {
1025                 pr_err("can't add fou ops\n");
1026                 return ret;
1027         }
1028 
1029         ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1030         if (ret < 0) {
1031                 pr_err("can't add gue ops\n");
1032                 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1033                 return ret;
1034         }
1035 
1036         return 0;
1037 }
1038 
1039 static void ip_tunnel_encap_del_fou_ops(void)
1040 {
1041         ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1042         ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1043 }
1044 
1045 #else
1046 
1047 static int ip_tunnel_encap_add_fou_ops(void)
1048 {
1049         return 0;
1050 }
1051 
1052 static void ip_tunnel_encap_del_fou_ops(void)
1053 {
1054 }
1055 
1056 #endif
1057 
1058 static __net_init int fou_init_net(struct net *net)
1059 {
1060         struct fou_net *fn = net_generic(net, fou_net_id);
1061 
1062         INIT_LIST_HEAD(&fn->fou_list);
1063         mutex_init(&fn->fou_lock);
1064         return 0;
1065 }
1066 
1067 static __net_exit void fou_exit_net(struct net *net)
1068 {
1069         struct fou_net *fn = net_generic(net, fou_net_id);
1070         struct fou *fou, *next;
1071 
1072         /* Close all the FOU sockets */
1073         mutex_lock(&fn->fou_lock);
1074         list_for_each_entry_safe(fou, next, &fn->fou_list, list)
1075                 fou_release(fou);
1076         mutex_unlock(&fn->fou_lock);
1077 }
1078 
1079 static struct pernet_operations fou_net_ops = {
1080         .init = fou_init_net,
1081         .exit = fou_exit_net,
1082         .id   = &fou_net_id,
1083         .size = sizeof(struct fou_net),
1084 };
1085 
1086 static int __init fou_init(void)
1087 {
1088         int ret;
1089 
1090         ret = register_pernet_device(&fou_net_ops);
1091         if (ret)
1092                 goto exit;
1093 
1094         ret = genl_register_family(&fou_nl_family);
1095         if (ret < 0)
1096                 goto unregister;
1097 
1098         ret = ip_tunnel_encap_add_fou_ops();
1099         if (ret == 0)
1100                 return 0;
1101 
1102         genl_unregister_family(&fou_nl_family);
1103 unregister:
1104         unregister_pernet_device(&fou_net_ops);
1105 exit:
1106         return ret;
1107 }
1108 
1109 static void __exit fou_fini(void)
1110 {
1111         ip_tunnel_encap_del_fou_ops();
1112         genl_unregister_family(&fou_nl_family);
1113         unregister_pernet_device(&fou_net_ops);
1114 }
1115 
1116 module_init(fou_init);
1117 module_exit(fou_fini);
1118 MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
1119 MODULE_LICENSE("GPL");
1120 

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