net/ipv4/fou.c

   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/ip.h>
  12 #include <net/protocol.h>
  13 #include <net/udp.h>
  14 #include <net/udp_tunnel.h>
  15 #include <net/xfrm.h>
  16 #include <uapi/linux/fou.h>
  17 #include <uapi/linux/genetlink.h>
  18
  19 struct fou {
  20         struct socket *sock;
  21         u8 protocol;
  22         u8 flags;
  23         __be16 port;
  24         u8 family;
  25         u16 type;
  26         struct list_head list;
  27         struct rcu_head rcu;
  28 };
  29
  30 #define FOU_F_REMCSUM_NOPARTIAL BIT(0)
  31
  32 struct fou_cfg {
  33         u16 type;
  34         u8 protocol;
  35         u8 flags;
  36         struct udp_port_cfg udp_config;
  37 };
  38
  39 static unsigned int fou_net_id;
  40
  41 struct fou_net {
  42         struct list_head fou_list;
  43         struct mutex fou_lock;
  44 };
  45
  46 static inline struct fou *fou_from_sock(struct sock *sk)
  47 {
  48         return sk->sk_user_data;
  49 }
  50
  51 static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len)
  52 {
  53         /* Remove 'len' bytes from the packet (UDP header and
  54          * FOU header if present).
  55          */
  56         if (fou->family == AF_INET)
  57                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
  58         else
  59                 ipv6_hdr(skb)->payload_len =
  60                     htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
  61
  62         __skb_pull(skb, len);
  63         skb_postpull_rcsum(skb, udp_hdr(skb), len);
  64         skb_reset_transport_header(skb);
  65         return iptunnel_pull_offloads(skb);
  66 }
  67
  68 static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
  69 {
  70         struct fou *fou = fou_from_sock(sk);
  71
  72         if (!fou)
  73                 return 1;
  74
  75         if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
  76                 goto drop;
  77
  78         return -fou->protocol;
  79
  80 drop:
  81         kfree_skb(skb);
  82         return 0;
  83 }
  84
  85 static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
  86                                   void *data, size_t hdrlen, u8 ipproto,
  87                                   bool nopartial)
  88 {
  89         __be16 *pd = data;
  90         size_t start = ntohs(pd[0]);
  91         size_t offset = ntohs(pd[1]);
  92         size_t plen = sizeof(struct udphdr) + hdrlen +
  93             max_t(size_t, offset + sizeof(u16), start);
  94
  95         if (skb->remcsum_offload)
  96                 return guehdr;
  97
  98         if (!pskb_may_pull(skb, plen))
  99                 return NULL;
 100         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
 101
 102         skb_remcsum_process(skb, (void *)guehdr + hdrlen,
 103                             start, offset, nopartial);
 104
 105         return guehdr;
 106 }
 107
 108 static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
 109 {
 110         /* No support yet */
 111         kfree_skb(skb);
 112         return 0;
 113 }
 114
 115 static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
 116 {
 117         struct fou *fou = fou_from_sock(sk);
 118         size_t len, optlen, hdrlen;
 119         struct guehdr *guehdr;
 120         void *data;
 121         u16 doffset = 0;
 122
 123         if (!fou)
 124                 return 1;
 125
 126         len = sizeof(struct udphdr) + sizeof(struct guehdr);
 127         if (!pskb_may_pull(skb, len))
 128                 goto drop;
 129
 130         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
 131
 132         switch (guehdr->version) {
 133         case 0: /* Full GUE header present */
 134                 break;
 135
 136         case 1: {
 137                 /* Direct encasulation of IPv4 or IPv6 */
 138
 139                 int prot;
 140
 141                 switch (((struct iphdr *)guehdr)->version) {
 142                 case 4:
 143                         prot = IPPROTO_IPIP;
 144                         break;
 145                 case 6:
 146                         prot = IPPROTO_IPV6;
 147                         break;
 148                 default:
 149                         goto drop;
 150                 }
 151
 152                 if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
 153                         goto drop;
 154
 155                 return -prot;
 156         }
 157
 158         default: /* Undefined version */
 159                 goto drop;
 160         }
 161
 162         optlen = guehdr->hlen << 2;
 163         len += optlen;
 164
 165         if (!pskb_may_pull(skb, len))
 166                 goto drop;
 167
 168         /* guehdr may change after pull */
 169         guehdr = (struct guehdr *)&udp_hdr(skb)[1];
 170
 171         hdrlen = sizeof(struct guehdr) + optlen;
 172
 173         if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
 174                 goto drop;
 175
 176         hdrlen = sizeof(struct guehdr) + optlen;
 177
 178         if (fou->family == AF_INET)
 179                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
 180         else
 181                 ipv6_hdr(skb)->payload_len =
 182                     htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
 183
 184         /* Pull csum through the guehdr now . This can be used if
 185          * there is a remote checksum offload.
 186          */
 187         skb_postpull_rcsum(skb, udp_hdr(skb), len);
 188
 189         data = &guehdr[1];
 190
 191         if (guehdr->flags & GUE_FLAG_PRIV) {
 192                 __be32 flags = *(__be32 *)(data + doffset);
 193
 194                 doffset += GUE_LEN_PRIV;
 195
 196                 if (flags & GUE_PFLAG_REMCSUM) {
 197                         guehdr = gue_remcsum(skb, guehdr, data + doffset,
 198                                              hdrlen, guehdr->proto_ctype,
 199                                              !!(fou->flags &
 200                                                 FOU_F_REMCSUM_NOPARTIAL));
 201                         if (!guehdr)
 202                                 goto drop;
 203
 204                         data = &guehdr[1];
 205
 206                         doffset += GUE_PLEN_REMCSUM;
 207                 }
 208         }
 209
 210         if (unlikely(guehdr->control))
 211                 return gue_control_message(skb, guehdr);
 212
 213         __skb_pull(skb, sizeof(struct udphdr) + hdrlen);
 214         skb_reset_transport_header(skb);
 215
 216         if (iptunnel_pull_offloads(skb))
 217                 goto drop;
 218
 219         return -guehdr->proto_ctype;
 220
 221 drop:
 222         kfree_skb(skb);
 223         return 0;
 224 }
 225
 226 static struct sk_buff **fou_gro_receive(struct sock *sk,
 227                                         struct sk_buff **head,
 228                                         struct sk_buff *skb)
 229 {
 230         const struct net_offload *ops;
 231         struct sk_buff **pp = NULL;
 232         u8 proto = fou_from_sock(sk)->protocol;
 233         const struct net_offload **offloads;
 234
 235         /* We can clear the encap_mark for FOU as we are essentially doing
 236          * one of two possible things.  We are either adding an L4 tunnel
 237          * header to the outer L3 tunnel header, or we are are simply
 238          * treating the GRE tunnel header as though it is a UDP protocol
 239          * specific header such as VXLAN or GENEVE.
 240          */
 241         NAPI_GRO_CB(skb)->encap_mark = 0;
 242
 243         /* Flag this frame as already having an outer encap header */
 244         NAPI_GRO_CB(skb)->is_fou = 1;
 245
 246         rcu_read_lock();
 247         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 248         ops = rcu_dereference(offloads[proto]);
 249         if (!ops || !ops->callbacks.gro_receive)
 250                 goto out_unlock;
 251
 252         pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
 253
 254 out_unlock:
 255         rcu_read_unlock();
 256
 257         return pp;
 258 }
 259
 260 static int fou_gro_complete(struct sock *sk, struct sk_buff *skb,
 261                             int nhoff)
 262 {
 263         const struct net_offload *ops;
 264         u8 proto = fou_from_sock(sk)->protocol;
 265         int err = -ENOSYS;
 266         const struct net_offload **offloads;
 267
 268         rcu_read_lock();
 269         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 270         ops = rcu_dereference(offloads[proto]);
 271         if (WARN_ON(!ops || !ops->callbacks.gro_complete))
 272                 goto out_unlock;
 273
 274         err = ops->callbacks.gro_complete(skb, nhoff);
 275
 276         skb_set_inner_mac_header(skb, nhoff);
 277
 278 out_unlock:
 279         rcu_read_unlock();
 280
 281         return err;
 282 }
 283
 284 static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
 285                                       struct guehdr *guehdr, void *data,
 286                                       size_t hdrlen, struct gro_remcsum *grc,
 287                                       bool nopartial)
 288 {
 289         __be16 *pd = data;
 290         size_t start = ntohs(pd[0]);
 291         size_t offset = ntohs(pd[1]);
 292
 293         if (skb->remcsum_offload)
 294                 return guehdr;
 295
 296         if (!NAPI_GRO_CB(skb)->csum_valid)
 297                 return NULL;
 298
 299         guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen,
 300                                          start, offset, grc, nopartial);
 301
 302         skb->remcsum_offload = 1;
 303
 304         return guehdr;
 305 }
 306
 307 static struct sk_buff **gue_gro_receive(struct sock *sk,
 308                                         struct sk_buff **head,
 309                                         struct sk_buff *skb)
 310 {
 311         const struct net_offload **offloads;
 312         const struct net_offload *ops;
 313         struct sk_buff **pp = NULL;
 314         struct sk_buff *p;
 315         struct guehdr *guehdr;
 316         size_t len, optlen, hdrlen, off;
 317         void *data;
 318         u16 doffset = 0;
 319         int flush = 1;
 320         struct fou *fou = fou_from_sock(sk);
 321         struct gro_remcsum grc;
 322         u8 proto;
 323
 324         skb_gro_remcsum_init(&grc);
 325
 326         off = skb_gro_offset(skb);
 327         len = off + sizeof(*guehdr);
 328
 329         guehdr = skb_gro_header_fast(skb, off);
 330         if (skb_gro_header_hard(skb, len)) {
 331                 guehdr = skb_gro_header_slow(skb, len, off);
 332                 if (unlikely(!guehdr))
 333                         goto out;
 334         }
 335
 336         switch (guehdr->version) {
 337         case 0:
 338                 break;
 339         case 1:
 340                 switch (((struct iphdr *)guehdr)->version) {
 341                 case 4:
 342                         proto = IPPROTO_IPIP;
 343                         break;
 344                 case 6:
 345                         proto = IPPROTO_IPV6;
 346                         break;
 347                 default:
 348                         goto out;
 349                 }
 350                 goto next_proto;
 351         default:
 352                 goto out;
 353         }
 354
 355         optlen = guehdr->hlen << 2;
 356         len += optlen;
 357
 358         if (skb_gro_header_hard(skb, len)) {
 359                 guehdr = skb_gro_header_slow(skb, len, off);
 360                 if (unlikely(!guehdr))
 361                         goto out;
 362         }
 363
 364         if (unlikely(guehdr->control) || guehdr->version != 0 ||
 365             validate_gue_flags(guehdr, optlen))
 366                 goto out;
 367
 368         hdrlen = sizeof(*guehdr) + optlen;
 369
 370         /* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
 371          * this is needed if there is a remote checkcsum offload.
 372          */
 373         skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
 374
 375         data = &guehdr[1];
 376
 377         if (guehdr->flags & GUE_FLAG_PRIV) {
 378                 __be32 flags = *(__be32 *)(data + doffset);
 379
 380                 doffset += GUE_LEN_PRIV;
 381
 382                 if (flags & GUE_PFLAG_REMCSUM) {
 383                         guehdr = gue_gro_remcsum(skb, off, guehdr,
 384                                                  data + doffset, hdrlen, &grc,
 385                                                  !!(fou->flags &
 386                                                     FOU_F_REMCSUM_NOPARTIAL));
 387
 388                         if (!guehdr)
 389                                 goto out;
 390
 391                         data = &guehdr[1];
 392
 393                         doffset += GUE_PLEN_REMCSUM;
 394                 }
 395         }
 396
 397         skb_gro_pull(skb, hdrlen);
 398
 399         for (p = *head; p; p = p->next) {
 400                 const struct guehdr *guehdr2;
 401
 402                 if (!NAPI_GRO_CB(p)->same_flow)
 403                         continue;
 404
 405                 guehdr2 = (struct guehdr *)(p->data + off);
 406
 407                 /* Compare base GUE header to be equal (covers
 408                  * hlen, version, proto_ctype, and flags.
 409                  */
 410                 if (guehdr->word != guehdr2->word) {
 411                         NAPI_GRO_CB(p)->same_flow = 0;
 412                         continue;
 413                 }
 414
 415                 /* Compare optional fields are the same. */
 416                 if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
 417                                            guehdr->hlen << 2)) {
 418                         NAPI_GRO_CB(p)->same_flow = 0;
 419                         continue;
 420                 }
 421         }
 422
 423         proto = guehdr->proto_ctype;
 424
 425 next_proto:
 426
 427         /* We can clear the encap_mark for GUE as we are essentially doing
 428          * one of two possible things.  We are either adding an L4 tunnel
 429          * header to the outer L3 tunnel header, or we are are simply
 430          * treating the GRE tunnel header as though it is a UDP protocol
 431          * specific header such as VXLAN or GENEVE.
 432          */
 433         NAPI_GRO_CB(skb)->encap_mark = 0;
 434
 435         /* Flag this frame as already having an outer encap header */
 436         NAPI_GRO_CB(skb)->is_fou = 1;
 437
 438         rcu_read_lock();
 439         offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 440         ops = rcu_dereference(offloads[proto]);
 441         if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
 442                 goto out_unlock;
 443
 444         pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
 445         flush = 0;
 446
 447 out_unlock:
 448         rcu_read_unlock();
 449 out:
 450         NAPI_GRO_CB(skb)->flush |= flush;
 451         skb_gro_remcsum_cleanup(skb, &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 static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
 863                           struct flowi4 *fl4, u8 *protocol, __be16 sport)
 864 {
 865         struct udphdr *uh;
 866
 867         skb_push(skb, sizeof(struct udphdr));
 868         skb_reset_transport_header(skb);
 869
 870         uh = udp_hdr(skb);
 871
 872         uh->dest = e->dport;
 873         uh->source = sport;
 874         uh->len = htons(skb->len);
 875         udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
 876                      fl4->saddr, fl4->daddr, skb->len);
 877
 878         *protocol = IPPROTO_UDP;
 879 }
 880
 881 int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 882                        u8 *protocol, __be16 *sport, int type)
 883 {
 884         int err;
 885
 886         err = iptunnel_handle_offloads(skb, type);
 887         if (err)
 888                 return err;
 889
 890         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
 891                                                 skb, 0, 0, false);
 892
 893         return 0;
 894 }
 895 EXPORT_SYMBOL(__fou_build_header);
 896
 897 int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 898                      u8 *protocol, struct flowi4 *fl4)
 899 {
 900         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
 901                                                        SKB_GSO_UDP_TUNNEL;
 902         __be16 sport;
 903         int err;
 904
 905         err = __fou_build_header(skb, e, protocol, &sport, type);
 906         if (err)
 907                 return err;
 908
 909         fou_build_udp(skb, e, fl4, protocol, sport);
 910
 911         return 0;
 912 }
 913 EXPORT_SYMBOL(fou_build_header);
 914
 915 int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 916                        u8 *protocol, __be16 *sport, int type)
 917 {
 918         struct guehdr *guehdr;
 919         size_t hdrlen, optlen = 0;
 920         void *data;
 921         bool need_priv = false;
 922         int err;
 923
 924         if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
 925             skb->ip_summed == CHECKSUM_PARTIAL) {
 926                 optlen += GUE_PLEN_REMCSUM;
 927                 type |= SKB_GSO_TUNNEL_REMCSUM;
 928                 need_priv = true;
 929         }
 930
 931         optlen += need_priv ? GUE_LEN_PRIV : 0;
 932
 933         err = iptunnel_handle_offloads(skb, type);
 934         if (err)
 935                 return err;
 936
 937         /* Get source port (based on flow hash) before skb_push */
 938         *sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
 939                                                 skb, 0, 0, false);
 940
 941         hdrlen = sizeof(struct guehdr) + optlen;
 942
 943         skb_push(skb, hdrlen);
 944
 945         guehdr = (struct guehdr *)skb->data;
 946
 947         guehdr->control = 0;
 948         guehdr->version = 0;
 949         guehdr->hlen = optlen >> 2;
 950         guehdr->flags = 0;
 951         guehdr->proto_ctype = *protocol;
 952
 953         data = &guehdr[1];
 954
 955         if (need_priv) {
 956                 __be32 *flags = data;
 957
 958                 guehdr->flags |= GUE_FLAG_PRIV;
 959                 *flags = 0;
 960                 data += GUE_LEN_PRIV;
 961
 962                 if (type & SKB_GSO_TUNNEL_REMCSUM) {
 963                         u16 csum_start = skb_checksum_start_offset(skb);
 964                         __be16 *pd = data;
 965
 966                         if (csum_start < hdrlen)
 967                                 return -EINVAL;
 968
 969                         csum_start -= hdrlen;
 970                         pd[0] = htons(csum_start);
 971                         pd[1] = htons(csum_start + skb->csum_offset);
 972
 973                         if (!skb_is_gso(skb)) {
 974                                 skb->ip_summed = CHECKSUM_NONE;
 975                                 skb->encapsulation = 0;
 976                         }
 977
 978                         *flags |= GUE_PFLAG_REMCSUM;
 979                         data += GUE_PLEN_REMCSUM;
 980                 }
 981
 982         }
 983
 984         return 0;
 985 }
 986 EXPORT_SYMBOL(__gue_build_header);
 987
 988 int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 989                      u8 *protocol, struct flowi4 *fl4)
 990 {
 991         int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
 992                                                        SKB_GSO_UDP_TUNNEL;
 993         __be16 sport;
 994         int err;
 995
 996         err = __gue_build_header(skb, e, protocol, &sport, type);
 997         if (err)
 998                 return err;
 999
1000         fou_build_udp(skb, e, fl4, protocol, sport);
1001
1002         return 0;
1003 }
1004 EXPORT_SYMBOL(gue_build_header);
1005
1006 #ifdef CONFIG_NET_FOU_IP_TUNNELS
1007
1008 static const struct ip_tunnel_encap_ops fou_iptun_ops = {
1009         .encap_hlen = fou_encap_hlen,
1010         .build_header = fou_build_header,
1011 };
1012
1013 static const struct ip_tunnel_encap_ops gue_iptun_ops = {
1014         .encap_hlen = gue_encap_hlen,
1015         .build_header = gue_build_header,
1016 };
1017
1018 static int ip_tunnel_encap_add_fou_ops(void)
1019 {
1020         int ret;
1021
1022         ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1023         if (ret < 0) {
1024                 pr_err("can't add fou ops\n");
1025                 return ret;
1026         }
1027
1028         ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1029         if (ret < 0) {
1030                 pr_err("can't add gue ops\n");
1031                 ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1032                 return ret;
1033         }
1034
1035         return 0;
1036 }
1037
1038 static void ip_tunnel_encap_del_fou_ops(void)
1039 {
1040         ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
1041         ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
1042 }
1043
1044 #else
1045
1046 static int ip_tunnel_encap_add_fou_ops(void)
1047 {
1048         return 0;
1049 }
1050
1051 static void ip_tunnel_encap_del_fou_ops(void)
1052 {
1053 }
1054
1055 #endif
1056
1057 static __net_init int fou_init_net(struct net *net)
1058 {
1059         struct fou_net *fn = net_generic(net, fou_net_id);
1060
1061         INIT_LIST_HEAD(&fn->fou_list);
1062         mutex_init(&fn->fou_lock);
1063         return 0;
1064 }
1065
1066 static __net_exit void fou_exit_net(struct net *net)
1067 {
1068         struct fou_net *fn = net_generic(net, fou_net_id);
1069         struct fou *fou, *next;
1070
1071         /* Close all the FOU sockets */
1072         mutex_lock(&fn->fou_lock);
1073         list_for_each_entry_safe(fou, next, &fn->fou_list, list)
1074                 fou_release(fou);
1075         mutex_unlock(&fn->fou_lock);
1076 }
1077
1078 static struct pernet_operations fou_net_ops = {
1079         .init = fou_init_net,
1080         .exit = fou_exit_net,
1081         .id   = &fou_net_id,
1082         .size = sizeof(struct fou_net),
1083 };
1084
1085 static int __init fou_init(void)
1086 {
1087         int ret;
1088
1089         ret = register_pernet_device(&fou_net_ops);
1090         if (ret)
1091                 goto exit;
1092
1093         ret = genl_register_family(&fou_nl_family);
1094         if (ret < 0)
1095                 goto unregister;
1096
1097         ret = ip_tunnel_encap_add_fou_ops();
1098         if (ret == 0)
1099                 return 0;
1100
1101         genl_unregister_family(&fou_nl_family);
1102 unregister:
1103         unregister_pernet_device(&fou_net_ops);
1104 exit:
1105         return ret;
1106 }
1107
1108 static void __exit fou_fini(void)
1109 {
1110         ip_tunnel_encap_del_fou_ops();
1111         genl_unregister_family(&fou_nl_family);
1112         unregister_pernet_device(&fou_net_ops);
1113 }
1114
1115 module_init(fou_init);
1116 module_exit(fou_fini);
1117 MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
1118 MODULE_LICENSE("GPL");