Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tree: f5c45121cf
Fetching contributors…

Cannot retrieve contributors at this time

file 847 lines (673 sloc) 21.858 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
/*
* Copyright (c) 2007-2012 Nicira, Inc.
* Distributed under the terms of the GNU GPL version 2.
*
* Significant portions of this file may be copied from parts of the Linux
* kernel, by Linus Torvalds and others.
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/version.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)

#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/list.h>
#include <linux/net.h>
#include <net/net_namespace.h>

#include <net/icmp.h>
#include <net/inet_frag.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/udp.h>

#include "datapath.h"
#include "tunnel.h"
#include "vport.h"
#include "vport-generic.h"

#define CAPWAP_SRC_PORT 58881
#define CAPWAP_DST_PORT 58882

#define CAPWAP_FRAG_TIMEOUT (30 * HZ)
#define CAPWAP_FRAG_MAX_MEM (256 * 1024)
#define CAPWAP_FRAG_PRUNE_MEM (192 * 1024)
#define CAPWAP_FRAG_SECRET_INTERVAL (10 * 60 * HZ)

/*
* The CAPWAP header is a mess, with all kinds of odd size bit fields that
* cross byte boundaries, which are difficult to represent correctly in
* various byte orderings. Luckily we only care about a few permutations, so
* statically create them and we can do very fast parsing by checking all 12
* fields in one go.
*/
#define CAPWAP_PREAMBLE_MASK __cpu_to_be32(0xFF000000)
#define CAPWAP_HLEN_SHIFT 17
#define CAPWAP_HLEN_MASK __cpu_to_be32(0x00F80000)
#define CAPWAP_RID_MASK __cpu_to_be32(0x0007C000)
#define CAPWAP_WBID_MASK __cpu_to_be32(0x00003E00)
#define CAPWAP_F_MASK __cpu_to_be32(0x000001FF)

#define CAPWAP_F_FRAG __cpu_to_be32(0x00000080)
#define CAPWAP_F_LASTFRAG __cpu_to_be32(0x00000040)
#define CAPWAP_F_WSI __cpu_to_be32(0x00000020)
#define CAPWAP_F_RMAC __cpu_to_be32(0x00000010)

#define CAPWAP_RMAC_LEN 4

/* Standard CAPWAP looks for a WBID value of 2.
* When we insert WSI field, use WBID value of 30, which has been
* proposed for all "experimental" usage - users with no reserved WBID value
* of their own.
*/
#define CAPWAP_WBID_30 __cpu_to_be32(0x00003C00)
#define CAPWAP_WBID_2 __cpu_to_be32(0x00000200)

#define FRAG_HDR (CAPWAP_F_FRAG)
#define FRAG_LAST_HDR (FRAG_HDR | CAPWAP_F_LASTFRAG)

/* Keyed packet, WBID 30, and length long enough to include WSI key */
#define CAPWAP_KEYED (CAPWAP_WBID_30 | CAPWAP_F_WSI | htonl(20 << CAPWAP_HLEN_SHIFT))
/* A backward-compatible packet, WBID 2 and length of 2 words (no WSI fields) */
#define CAPWAP_NO_WSI (CAPWAP_WBID_2 | htonl(8 << CAPWAP_HLEN_SHIFT))

/* Mask for all parts of header that must be 0. */
#define CAPWAP_ZERO_MASK (CAPWAP_PREAMBLE_MASK | \
(CAPWAP_F_MASK ^ (CAPWAP_F_WSI | CAPWAP_F_FRAG | CAPWAP_F_LASTFRAG | CAPWAP_F_RMAC)))

struct capwaphdr {
__be32 begin;
__be16 frag_id;
/* low 3 bits of frag_off are reserved */
__be16 frag_off;
};

/*
* We use the WSI field to hold additional tunnel data.
* The first eight bits store the size of the wsi data in bytes.
*/
struct capwaphdr_wsi {
u8 wsi_len;
u8 flags;
__be16 reserved_padding;
};

struct capwaphdr_wsi_key {
__be64 key;
};

/* Flag indicating a 64bit key is stored in WSI data field */
#define CAPWAP_WSI_F_KEY64 0x80

static struct capwaphdr *capwap_hdr(const struct sk_buff *skb)
{
return (struct capwaphdr *)(udp_hdr(skb) + 1);
}

/*
* The fragment offset is actually the high 13 bits of the last 16 bit field,
* so we would normally need to right shift 3 places. However, it stores the
* offset in 8 byte chunks, which would involve a 3 place left shift. So we
* just mask off the last 3 bits and be done with it.
*/
#define FRAG_OFF_MASK (~0x7U)

/*
* The minimum header length. The header may be longer if the optional
* WSI field is used.
*/
#define CAPWAP_MIN_HLEN (sizeof(struct udphdr) + sizeof(struct capwaphdr))

struct frag_match {
__be32 saddr;
__be32 daddr;
__be16 id;
};

struct frag_queue {
struct inet_frag_queue ifq;
struct frag_match match;
};

struct frag_skb_cb {
u16 offset;
};
#define FRAG_CB(skb) ((struct frag_skb_cb *)(skb)->cb)

static struct sk_buff *fragment(struct sk_buff *, const struct vport *,
struct dst_entry *dst, unsigned int hlen);
static struct sk_buff *defrag(struct sk_buff *, bool frag_last);

static void capwap_frag_init(struct inet_frag_queue *, void *match);
static unsigned int capwap_frag_hash(struct inet_frag_queue *);
static int capwap_frag_match(struct inet_frag_queue *, void *match);
static void capwap_frag_expire(unsigned long ifq);

static struct inet_frags frag_state = {
.constructor = capwap_frag_init,
.qsize = sizeof(struct frag_queue),
.hashfn = capwap_frag_hash,
.match = capwap_frag_match,
.frag_expire = capwap_frag_expire,
.secret_interval = CAPWAP_FRAG_SECRET_INTERVAL,
};

static int capwap_hdr_len(const struct tnl_mutable_config *mutable)
{
int size = CAPWAP_MIN_HLEN;

/* CAPWAP has no checksums. */
if (mutable->flags & TNL_F_CSUM)
return -EINVAL;

/* if keys are specified, then add WSI field */
if (mutable->out_key || (mutable->flags & TNL_F_OUT_KEY_ACTION)) {
size += sizeof(struct capwaphdr_wsi) +
sizeof(struct capwaphdr_wsi_key);
}

return size;
}

static void capwap_build_header(const struct vport *vport,
const struct tnl_mutable_config *mutable,
void *header)
{
struct udphdr *udph = header;
struct capwaphdr *cwh = (struct capwaphdr *)(udph + 1);

udph->source = htons(CAPWAP_SRC_PORT);
udph->dest = htons(CAPWAP_DST_PORT);
udph->check = 0;

cwh->frag_id = 0;
cwh->frag_off = 0;

if (mutable->out_key || (mutable->flags & TNL_F_OUT_KEY_ACTION)) {
struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1);

cwh->begin = CAPWAP_KEYED;

/* -1 for wsi_len byte, not included in length as per spec */
wsi->wsi_len = sizeof(struct capwaphdr_wsi) - 1
+ sizeof(struct capwaphdr_wsi_key);
wsi->flags = CAPWAP_WSI_F_KEY64;
wsi->reserved_padding = 0;

if (mutable->out_key) {
struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1);
opt->key = mutable->out_key;
}
} else {
/* make packet readable by old capwap code */
cwh->begin = CAPWAP_NO_WSI;
}
}

static struct sk_buff *capwap_update_header(const struct vport *vport,
const struct tnl_mutable_config *mutable,
struct dst_entry *dst,
struct sk_buff *skb)
{
struct udphdr *udph = udp_hdr(skb);

if (mutable->flags & TNL_F_OUT_KEY_ACTION) {
/* first field in WSI is key */
struct capwaphdr *cwh = (struct capwaphdr *)(udph + 1);
struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1);
struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1);

opt->key = OVS_CB(skb)->tun_id;
}

udph->len = htons(skb->len - skb_transport_offset(skb));

if (unlikely(skb->len - skb_network_offset(skb) > dst_mtu(dst))) {
unsigned int hlen = skb_transport_offset(skb) + capwap_hdr_len(mutable);
skb = fragment(skb, vport, dst, hlen);
}

return skb;
}

static int process_capwap_wsi(struct sk_buff *skb, __be64 *key)
{
struct capwaphdr *cwh = capwap_hdr(skb);
struct capwaphdr_wsi *wsi;
int hdr_len;
int rmac_len = 0;
int wsi_len;

if (((cwh->begin & CAPWAP_WBID_MASK) != CAPWAP_WBID_30))
return 0;

if (cwh->begin & CAPWAP_F_RMAC)
rmac_len = CAPWAP_RMAC_LEN;

hdr_len = ntohl(cwh->begin & CAPWAP_HLEN_MASK) >> CAPWAP_HLEN_SHIFT;

if (unlikely(sizeof(struct capwaphdr) + rmac_len + sizeof(struct capwaphdr_wsi) > hdr_len))
return -EINVAL;

/* read wsi header to find out how big it really is */
wsi = (struct capwaphdr_wsi *)((u8 *)(cwh + 1) + rmac_len);
/* +1 for length byte not included in wsi_len */
wsi_len = 1 + wsi->wsi_len;

if (unlikely(sizeof(struct capwaphdr) + rmac_len + wsi_len != hdr_len))
return -EINVAL;

wsi_len -= sizeof(struct capwaphdr_wsi);

if (wsi->flags & CAPWAP_WSI_F_KEY64) {
struct capwaphdr_wsi_key *opt;

if (unlikely(wsi_len < sizeof(struct capwaphdr_wsi_key)))
return -EINVAL;

opt = (struct capwaphdr_wsi_key *)(wsi + 1);
*key = opt->key;
}

return 0;
}

static struct sk_buff *process_capwap_proto(struct sk_buff *skb, __be64 *key)
{
struct capwaphdr *cwh = capwap_hdr(skb);
int hdr_len = sizeof(struct udphdr);

if (unlikely((cwh->begin & CAPWAP_ZERO_MASK) != 0))
goto error;

hdr_len += ntohl(cwh->begin & CAPWAP_HLEN_MASK) >> CAPWAP_HLEN_SHIFT;
if (unlikely(hdr_len < CAPWAP_MIN_HLEN))
goto error;

if (unlikely(!pskb_may_pull(skb, hdr_len + ETH_HLEN)))
goto error;

cwh = capwap_hdr(skb);
__skb_pull(skb, hdr_len);
skb_postpull_rcsum(skb, skb_transport_header(skb), hdr_len + ETH_HLEN);

if (cwh->begin & CAPWAP_F_FRAG) {
skb = defrag(skb, (__force bool)(cwh->begin & CAPWAP_F_LASTFRAG));
if (!skb)
return NULL;
cwh = capwap_hdr(skb);
}

if ((cwh->begin & CAPWAP_F_WSI) && process_capwap_wsi(skb, key))
goto error;

return skb;
error:
kfree_skb(skb);
return NULL;
}

/* Called with rcu_read_lock and BH disabled. */
static int capwap_rcv(struct sock *sk, struct sk_buff *skb)
{
struct vport *vport;
const struct tnl_mutable_config *mutable;
struct iphdr *iph;
__be64 key = 0;

if (unlikely(!pskb_may_pull(skb, CAPWAP_MIN_HLEN + ETH_HLEN)))
goto error;

skb = process_capwap_proto(skb, &key);
if (unlikely(!skb))
goto out;

iph = ip_hdr(skb);
vport = ovs_tnl_find_port(sock_net(sk), iph->daddr, iph->saddr, key,
TNL_T_PROTO_CAPWAP, &mutable);
if (unlikely(!vport)) {
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
goto error;
}

if (mutable->flags & TNL_F_IN_KEY_MATCH)
OVS_CB(skb)->tun_id = key;
else
OVS_CB(skb)->tun_id = 0;

ovs_tnl_rcv(vport, skb, iph->tos);
goto out;

error:
kfree_skb(skb);
out:
return 0;
}

static const struct tnl_ops capwap_tnl_ops = {
.tunnel_type = TNL_T_PROTO_CAPWAP,
.ipproto = IPPROTO_UDP,
.hdr_len = capwap_hdr_len,
.build_header = capwap_build_header,
.update_header = capwap_update_header,
};

static inline struct capwap_net *ovs_get_capwap_net(struct net *net)
{
struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
return &ovs_net->vport_net.capwap;
}

/* Arbitrary value. Irrelevant as long as it's not 0 since we set the handler. */
#define UDP_ENCAP_CAPWAP 10
static int init_socket(struct net *net)
{
int err;
struct capwap_net *capwap_net = ovs_get_capwap_net(net);
struct sockaddr_in sin;

if (capwap_net->n_tunnels) {
capwap_net->n_tunnels++;
return 0;
}

err = sock_create_kern(AF_INET, SOCK_DGRAM, 0,
&capwap_net->capwap_rcv_socket);
if (err)
goto error;

/* release net ref. */
sk_change_net(capwap_net->capwap_rcv_socket->sk, net);

sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_port = htons(CAPWAP_DST_PORT);

err = kernel_bind(capwap_net->capwap_rcv_socket,
(struct sockaddr *)&sin,
sizeof(struct sockaddr_in));
if (err)
goto error_sock;

udp_sk(capwap_net->capwap_rcv_socket->sk)->encap_type = UDP_ENCAP_CAPWAP;
udp_sk(capwap_net->capwap_rcv_socket->sk)->encap_rcv = capwap_rcv;

capwap_net->frag_state.timeout = CAPWAP_FRAG_TIMEOUT;
capwap_net->frag_state.high_thresh = CAPWAP_FRAG_MAX_MEM;
capwap_net->frag_state.low_thresh = CAPWAP_FRAG_PRUNE_MEM;

inet_frags_init_net(&capwap_net->frag_state);

capwap_net->n_tunnels++;
return 0;

error_sock:
sk_release_kernel(capwap_net->capwap_rcv_socket->sk);
error:
pr_warn("cannot register capwap protocol handler : %d\n", err);
return err;
}

static void release_socket(struct net *net)
{
struct capwap_net *capwap_net = ovs_get_capwap_net(net);

capwap_net->n_tunnels--;
if (capwap_net->n_tunnels)
return;

inet_frags_exit_net(&capwap_net->frag_state, &frag_state);
sk_release_kernel(capwap_net->capwap_rcv_socket->sk);
}

static struct vport *capwap_create(const struct vport_parms *parms)
{
struct vport *vport;
int err;

err = init_socket(ovs_dp_get_net(parms->dp));
if (err)
return ERR_PTR(err);

vport = ovs_tnl_create(parms, &ovs_capwap_vport_ops, &capwap_tnl_ops);
if (IS_ERR(vport))
release_socket(ovs_dp_get_net(parms->dp));

return vport;
}

static void capwap_destroy(struct vport *vport)
{
ovs_tnl_destroy(vport);
release_socket(ovs_dp_get_net(vport->dp));
}

static int capwap_init(void)
{
inet_frags_init(&frag_state);
return 0;
}

static void capwap_exit(void)
{
inet_frags_fini(&frag_state);
}

static void copy_skb_metadata(struct sk_buff *from, struct sk_buff *to)
{
to->pkt_type = from->pkt_type;
to->priority = from->priority;
to->protocol = from->protocol;
skb_dst_set(to, dst_clone(skb_dst(from)));
to->dev = from->dev;
to->mark = from->mark;

if (from->sk)
skb_set_owner_w(to, from->sk);

#ifdef CONFIG_NET_SCHED
to->tc_index = from->tc_index;
#endif
#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
to->ipvs_property = from->ipvs_property;
#endif
skb_copy_secmark(to, from);
}

static struct sk_buff *fragment(struct sk_buff *skb, const struct vport *vport,
struct dst_entry *dst, unsigned int hlen)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
unsigned int headroom;
unsigned int max_frame_len = dst_mtu(dst) + skb_network_offset(skb);
struct sk_buff *result = NULL, *list_cur = NULL;
unsigned int remaining;
unsigned int offset;
__be16 frag_id;

if (hlen + ~FRAG_OFF_MASK + 1 > max_frame_len) {
if (net_ratelimit())
pr_warn("capwap link mtu (%d) is less than minimum packet (%d)\n",
dst_mtu(dst),
hlen - skb_network_offset(skb) + ~FRAG_OFF_MASK + 1);
goto error;
}

remaining = skb->len - hlen;
offset = 0;
frag_id = htons(atomic_inc_return(&tnl_vport->frag_id));

headroom = dst->header_len + 16;
if (!skb_network_offset(skb))
headroom += LL_RESERVED_SPACE(dst->dev);

while (remaining) {
struct sk_buff *skb2;
int frag_size;
struct udphdr *udph;
struct capwaphdr *cwh;

frag_size = min(remaining, max_frame_len - hlen);
if (remaining > frag_size)
frag_size &= FRAG_OFF_MASK;

skb2 = alloc_skb(headroom + hlen + frag_size, GFP_ATOMIC);
if (!skb2)
goto error;

skb_reserve(skb2, headroom);
__skb_put(skb2, hlen + frag_size);

if (skb_network_offset(skb))
skb_reset_mac_header(skb2);
skb_set_network_header(skb2, skb_network_offset(skb));
skb_set_transport_header(skb2, skb_transport_offset(skb));

/* Copy (Ethernet)/IP/UDP/CAPWAP header. */
copy_skb_metadata(skb, skb2);
skb_copy_from_linear_data(skb, skb2->data, hlen);

/* Copy this data chunk. */
if (skb_copy_bits(skb, hlen + offset, skb2->data + hlen, frag_size))
BUG();

udph = udp_hdr(skb2);
udph->len = htons(skb2->len - skb_transport_offset(skb2));

cwh = capwap_hdr(skb2);
if (remaining > frag_size)
cwh->begin |= FRAG_HDR;
else
cwh->begin |= FRAG_LAST_HDR;
cwh->frag_id = frag_id;
cwh->frag_off = htons(offset);

if (result) {
list_cur->next = skb2;
list_cur = skb2;
} else
result = list_cur = skb2;

offset += frag_size;
remaining -= frag_size;
}

consume_skb(skb);
return result;

error:
ovs_tnl_free_linked_skbs(result);
kfree_skb(skb);
return NULL;
}

/* All of the following functions relate to fragmentation reassembly. */

static struct frag_queue *ifq_cast(struct inet_frag_queue *ifq)
{
return container_of(ifq, struct frag_queue, ifq);
}

static u32 frag_hash(struct frag_match *match)
{
return jhash_3words((__force u16)match->id, (__force u32)match->saddr,
(__force u32)match->daddr,
frag_state.rnd) & (INETFRAGS_HASHSZ - 1);
}

static struct frag_queue *queue_find(struct netns_frags *ns_frag_state,
struct frag_match *match)
{
struct inet_frag_queue *ifq;

read_lock(&frag_state.lock);

ifq = inet_frag_find(ns_frag_state, &frag_state, match, frag_hash(match));
if (!ifq)
return NULL;

/* Unlock happens inside inet_frag_find(). */

return ifq_cast(ifq);
}

static struct sk_buff *frag_reasm(struct frag_queue *fq, struct net_device *dev)
{
struct sk_buff *head = fq->ifq.fragments;
struct sk_buff *frag;

/* Succeed or fail, we're done with this queue. */
inet_frag_kill(&fq->ifq, &frag_state);

if (fq->ifq.len > 65535)
return NULL;

/* Can't have the head be a clone. */
if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
return NULL;

/*
* We're about to build frag list for this SKB. If it already has a
* frag list, alloc a new SKB and put the existing frag list there.
*/
if (skb_shinfo(head)->frag_list) {
int i;
int paged_len = 0;

frag = alloc_skb(0, GFP_ATOMIC);
if (!frag)
return NULL;

frag->next = head->next;
head->next = frag;
skb_shinfo(frag)->frag_list = skb_shinfo(head)->frag_list;
skb_shinfo(head)->frag_list = NULL;

for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
paged_len += skb_shinfo(head)->frags[i].size;
frag->len = frag->data_len = head->data_len - paged_len;
head->data_len -= frag->len;
head->len -= frag->len;

frag->ip_summed = head->ip_summed;
atomic_add(frag->truesize, &fq->ifq.net->mem);
}

skb_shinfo(head)->frag_list = head->next;
atomic_sub(head->truesize, &fq->ifq.net->mem);

/* Properly account for data in various packets. */
for (frag = head->next; frag; frag = frag->next) {
head->data_len += frag->len;
head->len += frag->len;

if (head->ip_summed != frag->ip_summed)
head->ip_summed = CHECKSUM_NONE;
else if (head->ip_summed == CHECKSUM_COMPLETE)
head->csum = csum_add(head->csum, frag->csum);

head->truesize += frag->truesize;
atomic_sub(frag->truesize, &fq->ifq.net->mem);
}

head->next = NULL;
head->dev = dev;
head->tstamp = fq->ifq.stamp;
fq->ifq.fragments = NULL;

return head;
}

static struct sk_buff *frag_queue(struct frag_queue *fq, struct sk_buff *skb,
u16 offset, bool frag_last)
{
struct sk_buff *prev, *next;
struct net_device *dev;
int end;

if (fq->ifq.last_in & INET_FRAG_COMPLETE)
goto error;

if (!skb->len)
goto error;

end = offset + skb->len;

if (frag_last) {
/*
* Last fragment, shouldn't already have data past our end or
* have another last fragment.
*/
if (end < fq->ifq.len || fq->ifq.last_in & INET_FRAG_LAST_IN)
goto error;

fq->ifq.last_in |= INET_FRAG_LAST_IN;
fq->ifq.len = end;
} else {
/* Fragments should align to 8 byte chunks. */
if (end & ~FRAG_OFF_MASK)
goto error;

if (end > fq->ifq.len) {
/*
* Shouldn't have data past the end, if we already
* have one.
*/
if (fq->ifq.last_in & INET_FRAG_LAST_IN)
goto error;

fq->ifq.len = end;
}
}

/* Find where we fit in. */
prev = NULL;
for (next = fq->ifq.fragments; next != NULL; next = next->next) {
if (FRAG_CB(next)->offset >= offset)
break;
prev = next;
}

/*
* Overlapping fragments aren't allowed. We shouldn't start before
* the end of the previous fragment.
*/
if (prev && FRAG_CB(prev)->offset + prev->len > offset)
goto error;

/* We also shouldn't end after the beginning of the next fragment. */
if (next && end > FRAG_CB(next)->offset)
goto error;

FRAG_CB(skb)->offset = offset;

/* Link into list. */
skb->next = next;
if (prev)
prev->next = skb;
else
fq->ifq.fragments = skb;

dev = skb->dev;
skb->dev = NULL;

fq->ifq.stamp = skb->tstamp;
fq->ifq.meat += skb->len;
atomic_add(skb->truesize, &fq->ifq.net->mem);
if (offset == 0)
fq->ifq.last_in |= INET_FRAG_FIRST_IN;

/* If we have all fragments do reassembly. */
if (fq->ifq.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
fq->ifq.meat == fq->ifq.len)
return frag_reasm(fq, dev);

write_lock(&frag_state.lock);
list_move_tail(&fq->ifq.lru_list, &fq->ifq.net->lru_list);
write_unlock(&frag_state.lock);

return NULL;

error:
kfree_skb(skb);
return NULL;
}

static struct sk_buff *defrag(struct sk_buff *skb, bool frag_last)
{
struct iphdr *iph = ip_hdr(skb);
struct capwaphdr *cwh = capwap_hdr(skb);
struct capwap_net *capwap_net = ovs_get_capwap_net(dev_net(skb->dev));
struct netns_frags *ns_frag_state = &capwap_net->frag_state;
struct frag_match match;
u16 frag_off;
struct frag_queue *fq;

if (atomic_read(&ns_frag_state->mem) > ns_frag_state->high_thresh)
inet_frag_evictor(ns_frag_state, &frag_state);

match.daddr = iph->daddr;
match.saddr = iph->saddr;
match.id = cwh->frag_id;
frag_off = ntohs(cwh->frag_off) & FRAG_OFF_MASK;

fq = queue_find(ns_frag_state, &match);
if (fq) {
spin_lock(&fq->ifq.lock);
skb = frag_queue(fq, skb, frag_off, frag_last);
spin_unlock(&fq->ifq.lock);

inet_frag_put(&fq->ifq, &frag_state);

return skb;
}

kfree_skb(skb);
return NULL;
}

static void capwap_frag_init(struct inet_frag_queue *ifq, void *match_)
{
struct frag_match *match = match_;

ifq_cast(ifq)->match = *match;
}

static unsigned int capwap_frag_hash(struct inet_frag_queue *ifq)
{
return frag_hash(&ifq_cast(ifq)->match);
}

static int capwap_frag_match(struct inet_frag_queue *ifq, void *a_)
{
struct frag_match *a = a_;
struct frag_match *b = &ifq_cast(ifq)->match;

return a->id == b->id && a->saddr == b->saddr && a->daddr == b->daddr;
}

/* Run when the timeout for a given queue expires. */
static void capwap_frag_expire(unsigned long ifq)
{
struct frag_queue *fq;

fq = ifq_cast((struct inet_frag_queue *)ifq);

spin_lock(&fq->ifq.lock);

if (!(fq->ifq.last_in & INET_FRAG_COMPLETE))
inet_frag_kill(&fq->ifq, &frag_state);

spin_unlock(&fq->ifq.lock);
inet_frag_put(&fq->ifq, &frag_state);
}

const struct vport_ops ovs_capwap_vport_ops = {
.type = OVS_VPORT_TYPE_CAPWAP,
.flags = VPORT_F_TUN_ID,
.init = capwap_init,
.exit = capwap_exit,
.create = capwap_create,
.destroy = capwap_destroy,
.set_addr = ovs_tnl_set_addr,
.get_name = ovs_tnl_get_name,
.get_addr = ovs_tnl_get_addr,
.get_options = ovs_tnl_get_options,
.set_options = ovs_tnl_set_options,
.get_dev_flags = ovs_vport_gen_get_dev_flags,
.is_running = ovs_vport_gen_is_running,
.get_operstate = ovs_vport_gen_get_operstate,
.send = ovs_tnl_send,
};
#else
#warning CAPWAP tunneling will not be available on kernels before 2.6.26
#endif /* Linux kernel < 2.6.26 */
Something went wrong with that request. Please try again.