[thirdparty/bird.git] / proto / ospf / lsalib.c

/*
 *	BIRD -- OSPF
 *
 *	(c) 1999--2004 Ondrej Filip <feela@network.cz>
 *	(c) 2009--2015 Ondrej Zajicek <santiago@crfreenet.org>
 *	(c) 2009--2015 CZ.NIC z.s.p.o.
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 */

#include "ospf.h"

#include "lib/fletcher16.h"

#define HDRLEN sizeof(struct ospf_lsa_header)


#ifndef CPU_BIG_ENDIAN
void
lsa_hton_hdr(struct ospf_lsa_header *h, struct ospf_lsa_header *n)
{
  n->age = htons(h->age);
  n->type_raw = htons(h->type_raw);
  n->id = htonl(h->id);
  n->rt = htonl(h->rt);
  n->sn = htonl(h->sn);
  n->checksum = htons(h->checksum);
  n->length = htons(h->length);
}

void
lsa_ntoh_hdr(struct ospf_lsa_header *n, struct ospf_lsa_header *h)
{
  h->age = ntohs(n->age);
  h->type_raw = ntohs(n->type_raw);
  h->id = ntohl(n->id);
  h->rt = ntohl(n->rt);
  h->sn = ntohl(n->sn);
  h->checksum = ntohs(n->checksum);
  h->length = ntohs(n->length);
}

void
lsa_hton_body(void *h, void *n, u16 len)
{
  u32 *hid = h;
  u32 *nid = n;
  uint i;

  for (i = 0; i < (len / sizeof(u32)); i++)
    nid[i] = htonl(hid[i]);
}

void
lsa_ntoh_body(void *n, void *h, u16 len)
{
  u32 *nid = n;
  u32 *hid = h;
  uint i;

  for (i = 0; i < (len / sizeof(u32)); i++)
    hid[i] = ntohl(nid[i]);
}
#endif /* little endian */


int
lsa_flooding_allowed(u32 type, u32 domain, struct ospf_iface *ifa)
{
  /* Handle inactive vlinks */
  if (ifa->state == OSPF_IS_DOWN)
    return 0;

  /* 4.5.2 (Case 2) */
  switch (LSA_SCOPE(type))
  {
  case LSA_SCOPE_LINK:
    return ifa->iface_id == domain;

  case LSA_SCOPE_AREA:
    return ifa->oa->areaid == domain;

  case LSA_SCOPE_AS:
    if (ifa->type == OSPF_IT_VLINK)
      return 0;
    if (!oa_is_ext(ifa->oa))
      return 0;
    return 1;

  default:
    log(L_ERR "OSPF: LSA with invalid scope");
    return 0;
  }
}

int
lsa_is_acceptable(u32 type, struct ospf_neighbor *n, struct ospf_proto *p)
{
  if (ospf_is_v2(p))
  {
    if (type == LSA_T_NSSA)
      return !!(n->options & OPT_N);

    if (lsa_is_opaque(type))
      return !!(n->options & OPT_O);

    return 1;
  }
  else
  {
    /*
     * There should be check whether receiving router understands that type
     * of LSA (for LSA types with U-bit == 0). But as we do not support any
     * optional LSA types, this is not needed yet.
     */

    return 1;
  }
}

static int
unknown_lsa_type(u32 type)
{
  switch (type)
  {
  case LSA_T_RT:
  case LSA_T_NET:
  case LSA_T_SUM_NET:
  case LSA_T_SUM_RT:
  case LSA_T_EXT:
  case LSA_T_NSSA:
  case LSA_T_LINK:
  case LSA_T_PREFIX:
  case LSA_T_RI_LINK:
  case LSA_T_RI_AREA:
  case LSA_T_RI_AS:
    return 0;

  default:
    return 1;
  }
}

/* Maps OSPFv2 types to OSPFv3 types */
static const u16 lsa_v2_types[] = {
  0, LSA_T_RT, LSA_T_NET, LSA_T_SUM_NET, LSA_T_SUM_RT, LSA_T_EXT, 0, LSA_T_NSSA,
  0, LSA_T_OPAQUE_LINK, LSA_T_OPAQUE_AREA, LSA_T_OPAQUE_AS
};

/* Maps OSPFv2 opaque types to OSPFv3 function codes */
static const u16 opaque_lsa_types[] = {
  [LSA_OT_GR] = LSA_T_GR,
  [LSA_OT_RI] = LSA_T_RI_,
};

/* Maps (subset of) OSPFv3 function codes to OSPFv2 opaque types */
static const u8 opaque_lsa_types_inv[] = {
  [LSA_T_GR] = LSA_OT_GR,
  [LSA_T_RI_] = LSA_OT_RI,
};

#define LOOKUP(a, i) ({ uint _i = (i); (_i < ARRAY_SIZE(a)) ? a[_i] : 0; })

void
lsa_get_type_domain_(u32 type, u32 id, struct ospf_iface *ifa, u32 *otype, u32 *domain)
{
  if (ospf_is_v2(ifa->oa->po))
  {
    type = type & LSA_T_V2_MASK;
    type = LOOKUP(lsa_v2_types, type);

    uint code;
    if (LSA_FUNCTION(type) == LSA_T_OPAQUE_)
      if (code = LOOKUP(opaque_lsa_types, id >> 24))
      {
	type = code | LSA_UBIT | LSA_SCOPE(type);

	/* Hack for Grace-LSA: It does not use U-bit for link-scoped LSAs */
	if (type == (LSA_T_GR | LSA_UBIT))
	  type = LSA_T_GR;
      }
  }
  else
  {
    /* For unkown LSAs without U-bit change scope to LSA_SCOPE_LINK */
    if (unknown_lsa_type(type) && !(type & LSA_UBIT))
      type = type & ~LSA_SCOPE_MASK;
  }

  *otype = type;

  switch (LSA_SCOPE(type))
  {
  case LSA_SCOPE_LINK:
    *domain = ifa->iface_id;
    return;

  case LSA_SCOPE_AREA:
    *domain = ifa->oa->areaid;
    return;

  case LSA_SCOPE_AS:
  default:
    *domain = 0;
    return;
  }
}

int
lsa_is_opaque(u32 type)
{
  u32 fn = LSA_FUNCTION(type);
  return LOOKUP(opaque_lsa_types_inv, fn) || (fn == LSA_T_OPAQUE_);
}

u32
lsa_get_opaque_type(u32 type)
{
  return LOOKUP(opaque_lsa_types_inv, LSA_FUNCTION(type));
}


void
lsa_generate_checksum(struct ospf_lsa_header *lsa, const u8 *body)
{
  struct fletcher16_context ctx;
  struct ospf_lsa_header hdr;
  u16 len = lsa->length;

  /*
   * lsa and body are in the host order, we need to compute Fletcher-16 checksum
   * for data in the network order. We also skip the initial age field.
   */

  lsa_hton_hdr(lsa, &hdr);
  hdr.checksum = 0;

  fletcher16_init(&ctx);
  fletcher16_update(&ctx, (u8 *) &hdr + 2, sizeof(struct ospf_lsa_header) - 2);
  fletcher16_update_n32(&ctx, body, len - sizeof(struct ospf_lsa_header));
  lsa->checksum = fletcher16_final(&ctx, len, OFFSETOF(struct ospf_lsa_header, checksum));
}

u16
lsa_verify_checksum(const void *lsa_n, int lsa_len)
{
  struct fletcher16_context ctx;

  /* The whole LSA is at lsa_n in net order, we just skip initial age field */

  fletcher16_init(&ctx);
  fletcher16_update(&ctx, (u8 *) lsa_n + 2, lsa_len - 2);

  return fletcher16_compute(&ctx) == 0;
}


int
lsa_comp(struct ospf_lsa_header *l1, struct ospf_lsa_header *l2)
			/* Return codes from point of view of l1 */
{
  u32 sn1, sn2;

  sn1 = l1->sn - LSA_INITSEQNO + 1;
  sn2 = l2->sn - LSA_INITSEQNO + 1;

  if (sn1 > sn2)
    return CMP_NEWER;
  if (sn1 < sn2)
    return CMP_OLDER;

  if (l1->checksum != l2->checksum)
    return l1->checksum < l2->checksum ? CMP_OLDER : CMP_NEWER;

  if ((l1->age == LSA_MAXAGE) && (l2->age != LSA_MAXAGE))
    return CMP_NEWER;
  if ((l2->age == LSA_MAXAGE) && (l1->age != LSA_MAXAGE))
    return CMP_OLDER;

  if (ABS(l1->age - l2->age) > LSA_MAXAGEDIFF)
    return l1->age < l2->age ? CMP_NEWER : CMP_OLDER;

  return CMP_SAME;
}


#define LSA_TLV_LENGTH(tlv) \
  (sizeof(struct ospf_tlv) + BIRD_ALIGN((tlv)->length, 4))

#define LSA_NEXT_TLV(tlv) \
  ((struct ospf_tlv *) ((byte *) (tlv) + LSA_TLV_LENGTH(tlv)))

#define LSA_WALK_TLVS(tlv,buf,len)					\
  for(struct ospf_tlv *tlv = (void *) (buf);				\
      (byte *) tlv < (byte *) (buf) + (len);				\
      tlv = LSA_NEXT_TLV(tlv))

struct ospf_tlv *
lsa_get_tlv(struct top_hash_entry *en, uint type)
{
  LSA_WALK_TLVS(tlv, en->lsa_body, en->lsa.length - HDRLEN)
    if (tlv->type == type)
      return tlv;

  return NULL;
}

int
lsa_validate_tlvs(byte *buf, uint len)
{
  byte *pos = buf;
  byte *end = buf + len;

  while (pos < end)
  {
    if ((pos + sizeof(struct ospf_tlv)) > end)
      return 0;

    struct ospf_tlv *tlv = (void *) pos;
    uint len = LSA_TLV_LENGTH(tlv);

    if ((pos + len) > end)
      return 0;

    pos += len;
  }

  return 1;
}


static inline int
lsa_walk_rt2(struct ospf_lsa_rt_walk *rt)
{
  if (rt->buf >= rt->bufend)
    return 0;

  struct ospf_lsa_rt2_link *l = rt->buf;
  rt->buf += sizeof(struct ospf_lsa_rt2_link) + l->no_tos * sizeof(struct ospf_lsa_rt2_tos);

  rt->type = l->type;
  rt->metric = l->metric;
  rt->id = l->id;
  rt->data = l->data;
  return 1;
}

static inline int
lsa_walk_rt3(struct ospf_lsa_rt_walk *rt)
{
  while (rt->buf >= rt->bufend)
  {
    rt->en = ospf_hash_find_rt3_next(rt->en);
    if (!rt->en)
      return 0;

    rt->buf = rt->en->lsa_body;
    rt->bufend = rt->buf + rt->en->lsa.length - sizeof(struct ospf_lsa_header);
    rt->buf += sizeof(struct ospf_lsa_rt);
  }

  struct ospf_lsa_rt3_link *l = rt->buf;
  rt->buf += sizeof(struct ospf_lsa_rt3_link);

  rt->type = l->type;
  rt->metric = l->metric;
  rt->lif = l->lif;
  rt->nif = l->nif;
  rt->id = l->id;
  return 1;
}

void
lsa_walk_rt_init(struct ospf_proto *p, struct top_hash_entry *act, struct ospf_lsa_rt_walk *rt)
{
  rt->ospf2 = ospf_is_v2(p);
  rt->id = rt->data = rt->lif = rt->nif = 0;

  if (rt->ospf2)
    rt->en = act;
  else
    rt->en = ospf_hash_find_rt3_first(p->gr, act->domain, act->lsa.rt);

  rt->buf = rt->en->lsa_body;
  rt->bufend = rt->buf + rt->en->lsa.length - sizeof(struct ospf_lsa_header);
  rt->buf += sizeof(struct ospf_lsa_rt);
}

int
lsa_walk_rt(struct ospf_lsa_rt_walk *rt)
{
  return rt->ospf2 ? lsa_walk_rt2(rt) : lsa_walk_rt3(rt);
}


void
lsa_parse_sum_net(struct top_hash_entry *en, int ospf2, int af, net_addr *net, u8 *pxopts, u32 *metric)
{
  if (ospf2)
  {
    uint opts = lsa_get_options(&en->lsa);
    struct ospf_lsa_sum2 *ls = en->lsa_body;
    net_fill_ip4(net, ip4_from_u32(en->lsa.id & ls->netmask), u32_masklen(ls->netmask));
    *pxopts = (opts & OPT_DN) ? OPT_PX_DN : 0;
    *metric = ls->metric & LSA_METRIC_MASK;
  }
  else
  {
    struct ospf_lsa_sum3_net *ls = en->lsa_body;
    ospf3_get_prefix(ls->prefix, af, net, pxopts, NULL);
    *metric = ls->metric & LSA_METRIC_MASK;
  }
}

void
lsa_parse_sum_rt(struct top_hash_entry *en, int ospf2, u32 *drid, u32 *metric, u32 *options)
{
  if (ospf2)
  {
    struct ospf_lsa_sum2 *ls = en->lsa_body;
    *drid = en->lsa.id;
    *metric = ls->metric & LSA_METRIC_MASK;
    *options = 0;
  }
  else
  {
    struct ospf_lsa_sum3_rt *ls = en->lsa_body;
    *drid = ls->drid;
    *metric = ls->metric & LSA_METRIC_MASK;
    *options = ls->options & LSA_OPTIONS_MASK;
  }
}

void
lsa_parse_ext(struct top_hash_entry *en, int ospf2, int af, struct ospf_lsa_ext_local *rt)
{
  if (ospf2)
  {
    struct ospf_lsa_ext2 *ext = en->lsa_body;
    net_fill_ip4(&rt->net,
		 ip4_from_u32(en->lsa.id & ext->netmask),
		 u32_masklen(ext->netmask));
    rt->pxopts = 0;
    rt->metric = ext->metric & LSA_METRIC_MASK;
    rt->ebit = ext->metric & LSA_EXT2_EBIT;

    rt->fbit = ext->fwaddr;
    rt->fwaddr = ipa_from_u32(ext->fwaddr);

    rt->tag = ext->tag;
    rt->propagate = lsa_get_options(&en->lsa) & OPT_P;
    rt->downwards = lsa_get_options(&en->lsa) & OPT_DN;
  }
  else
  {
    struct ospf_lsa_ext3 *ext = en->lsa_body;
    u32 *buf = ospf3_get_prefix(ext->rest, af, &rt->net, &rt->pxopts, NULL);
    rt->metric = ext->metric & LSA_METRIC_MASK;
    rt->ebit = ext->metric & LSA_EXT3_EBIT;

    rt->fbit = ext->metric & LSA_EXT3_FBIT;
    if (rt->fbit)
      buf = ospf3_get_addr(buf, af, &rt->fwaddr);
    else
      rt->fwaddr = IPA_NONE;

    rt->tag = (ext->metric & LSA_EXT3_TBIT) ? *buf++ : 0;
    rt->propagate = rt->pxopts & OPT_PX_P;
    rt->downwards = rt->pxopts & OPT_PX_DN;
  }
}


static int
lsa_validate_rt2(struct ospf_lsa_header *lsa, struct ospf_lsa_rt *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_rt)))
    return 0;

  uint i = 0;
  void *buf = body;
  void *bufend = buf + lsa->length - HDRLEN;
  buf += sizeof(struct ospf_lsa_rt);

  while (buf < bufend)
  {
    struct ospf_lsa_rt2_link *l = buf;
    buf += sizeof(struct ospf_lsa_rt2_link) + l->no_tos * sizeof(struct ospf_lsa_rt2_tos);
    i++;

    if (buf > bufend)
      return 0;

    if (!((l->type == LSART_PTP) ||
	  (l->type == LSART_NET) ||
	  (l->type == LSART_STUB) ||
	  (l->type == LSART_VLNK)))
      return 0;
  }

  if ((body->options & LSA_RT2_LINKS) != i)
    return 0;

  return 1;
}


static int
lsa_validate_rt3(struct ospf_lsa_header *lsa, struct ospf_lsa_rt *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_rt)))
    return 0;

  void *buf = body;
  void *bufend = buf + lsa->length - HDRLEN;
  buf += sizeof(struct ospf_lsa_rt);

  while (buf < bufend)
  {
    struct ospf_lsa_rt3_link *l = buf;
    buf += sizeof(struct ospf_lsa_rt3_link);

    if (buf > bufend)
      return 0;

    if (!((l->type == LSART_PTP) ||
	  (l->type == LSART_NET) ||
	  (l->type == LSART_VLNK)))
      return 0;
  }
  return 1;
}

static int
lsa_validate_net(struct ospf_lsa_header *lsa, struct ospf_lsa_net *body UNUSED)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_net)))
    return 0;

  return 1;
}

static int
lsa_validate_sum2(struct ospf_lsa_header *lsa, struct ospf_lsa_sum2 *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum2)))
    return 0;

  /* First field should have TOS = 0, we ignore other TOS fields */
  if ((body->metric & LSA_SUM2_TOS) != 0)
    return 0;

  return 1;
}

static inline int
pxlen(u32 *buf)
{
  return *buf >> 24;
}

static int
lsa_validate_sum3_net(struct ospf_lsa_header *lsa, struct ospf_lsa_sum3_net *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum3_net) + 4))
    return 0;

  u8 pxl = pxlen(body->prefix);
  if (pxl > IP6_MAX_PREFIX_LENGTH)
    return 0;

  if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum3_net) +
		      IPV6_PREFIX_SPACE(pxl)))
    return 0;

  return 1;
}

static int
lsa_validate_sum3_rt(struct ospf_lsa_header *lsa, struct ospf_lsa_sum3_rt *body UNUSED)
{
  if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum3_rt)))
    return 0;

  return 1;
}

static int
lsa_validate_ext2(struct ospf_lsa_header *lsa, struct ospf_lsa_ext2 *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext2)))
    return 0;

  /* First field should have TOS = 0, we ignore other TOS fields */
  if ((body->metric & LSA_EXT2_TOS) != 0)
    return 0;

  return 1;
}

static int
lsa_validate_ext3(struct ospf_lsa_header *lsa, struct ospf_lsa_ext3 *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext3) + 4))
    return 0;

  u8 pxl = pxlen(body->rest);
  if (pxl > IP6_MAX_PREFIX_LENGTH)
    return 0;

  int len = IPV6_PREFIX_SPACE(pxl);
  if (body->metric & LSA_EXT3_FBIT) // forwarding address
    len += 16;
  if (body->metric & LSA_EXT3_TBIT) // route tag
    len += 4;
  if (*body->rest & 0xFFFF) // referenced LS type field
    len += 4;

  if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_ext3) + len))
    return 0;

  return 1;
}

static int
lsa_validate_pxlist(struct ospf_lsa_header *lsa, u32 pxcount, uint offset, u8 *pbuf)
{
  uint bound = lsa->length - HDRLEN - 4;
  u32 i;

  for (i = 0; i < pxcount; i++)
    {
      if (offset > bound)
	return 0;

      u8 pxl = pxlen((u32 *) (pbuf + offset));
      if (pxl > IP6_MAX_PREFIX_LENGTH)
	return 0;

      offset += IPV6_PREFIX_SPACE(pxl);
    }

  if (lsa->length != (HDRLEN + offset))
    return 0;

  return 1;
}

static int
lsa_validate_link(struct ospf_lsa_header *lsa, struct ospf_lsa_link *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_link)))
    return 0;

  return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_link), (u8 *) body);
}

static int
lsa_validate_prefix(struct ospf_lsa_header *lsa, struct ospf_lsa_prefix *body)
{
  if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_prefix)))
    return 0;

  return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_prefix), (u8 *) body);
}

static int
lsa_validate_gr(struct ospf_lsa_header *lsa, void *body)
{
  return lsa_validate_tlvs(body, lsa->length - HDRLEN);
}

static int
lsa_validate_ri(struct ospf_lsa_header *lsa UNUSED, struct ospf_lsa_net *body UNUSED)
{
  /*
   * There should be proper validation. But we do not really process RI LSAs, so
   * we can just accept them like another unknown opaque LSAs.
   */

  return 1;
}


/**
 * lsa_validate - check whether given LSA is valid
 * @lsa: LSA header
 * @lsa_type: internal LSA type (%LSA_T_xxx)
 * @ospf2: %true for OSPFv2, %false for OSPFv3
 * @body: pointer to LSA body
 *
 * Checks internal structure of given LSA body (minimal length,
 * consistency). Returns true if valid.
 */
int
lsa_validate(struct ospf_lsa_header *lsa, u32 lsa_type, int ospf2, void *body)
{
  if (ospf2)
  {
    switch (lsa_type)
    {
    case LSA_T_RT:
      return lsa_validate_rt2(lsa, body);
    case LSA_T_NET:
      return lsa_validate_net(lsa, body);
    case LSA_T_SUM_NET:
      return lsa_validate_sum2(lsa, body);
    case LSA_T_SUM_RT:
      return lsa_validate_sum2(lsa, body);
    case LSA_T_EXT:
    case LSA_T_NSSA:
      return lsa_validate_ext2(lsa, body);
    case LSA_T_GR:
      return lsa_validate_gr(lsa, body);
    case LSA_T_RI_LINK:
    case LSA_T_RI_AREA:
    case LSA_T_RI_AS:
      return lsa_validate_ri(lsa, body);
    case LSA_T_OPAQUE_LINK:
    case LSA_T_OPAQUE_AREA:
    case LSA_T_OPAQUE_AS:
      return 1;	/* Unknown Opaque LSAs */
    default:
      return 0;	/* Should not happen, unknown LSAs are already rejected */
    }
  }
  else
  {
    switch (lsa_type)
    {
    case LSA_T_RT:
      return lsa_validate_rt3(lsa, body);
    case LSA_T_NET:
      return lsa_validate_net(lsa, body);
    case LSA_T_SUM_NET:
      return lsa_validate_sum3_net(lsa, body);
    case LSA_T_SUM_RT:
      return lsa_validate_sum3_rt(lsa, body);
    case LSA_T_EXT:
    case LSA_T_NSSA:
      return lsa_validate_ext3(lsa, body);
    case LSA_T_LINK:
      return lsa_validate_link(lsa, body);
    case LSA_T_PREFIX:
      return lsa_validate_prefix(lsa, body);
    case LSA_T_GR:
      return lsa_validate_gr(lsa, body);
    case LSA_T_RI_LINK:
    case LSA_T_RI_AREA:
    case LSA_T_RI_AS:
      return lsa_validate_ri(lsa, body);
    default:
      return 1;	/* Unknown LSAs are OK in OSPFv3 */
    }
  }
}
Commit	Line	Data
f45fd316 OF	1	/*
	2	* BIRD -- OSPF
	3	*
6f3203fa	4	* (c) 1999--2004 Ondrej Filip <feela@network.cz>
77edab64 OZ	5	* (c) 2009--2015 Ondrej Zajicek <santiago@crfreenet.org>
77edab64 OZ	6	* (c) 2009--2015 CZ.NIC z.s.p.o.
f45fd316 OF	7	*
	8	* Can be freely distributed and used under the terms of the GNU GPL.
	9	*/
	10
	11	#include "ospf.h"
	12
77edab64	13	#include "lib/fletcher16.h"
c45f48fb	14
1a2ad348 OZ	15	#define HDRLEN sizeof(struct ospf_lsa_header)
	16
	17
4e5fb4b6	18	#ifndef CPU_BIG_ENDIAN
f45fd316	19	void
70945cb6	20	lsa_hton_hdr(struct ospf_lsa_header h, struct ospf_lsa_header n)
f45fd316	21	{
2e10a170	22	n->age = htons(h->age);
70945cb6	23	n->type_raw = htons(h->type_raw);
2e10a170 OF	24	n->id = htonl(h->id);
	25	n->rt = htonl(h->rt);
	26	n->sn = htonl(h->sn);
	27	n->checksum = htons(h->checksum);
	28	n->length = htons(h->length);
c15e5690	29	}
f45fd316 OF	30
f45fd316 OF	31	void
70945cb6	32	lsa_ntoh_hdr(struct ospf_lsa_header n, struct ospf_lsa_header h)
f45fd316	33	{
2e10a170	34	h->age = ntohs(n->age);
70945cb6	35	h->type_raw = ntohs(n->type_raw);
2e10a170 OF	36	h->id = ntohl(n->id);
	37	h->rt = ntohl(n->rt);
	38	h->sn = ntohl(n->sn);
	39	h->checksum = ntohs(n->checksum);
	40	h->length = ntohs(n->length);
c15e5690	41	}
f45fd316 OF	42
f45fd316 OF	43	void
70945cb6	44	lsa_hton_body(void h, void n, u16 len)
f45fd316	45	{
c15e5690 OZ	46	u32 *hid = h;
c15e5690 OZ	47	u32 *nid = n;
70945cb6	48	uint i;
f45fd316	49
c15e5690 OZ	50	for (i = 0; i < (len / sizeof(u32)); i++)
	51	nid[i] = htonl(hid[i]);
	52	}
f45fd316 OF	53
f45fd316 OF	54	void
70945cb6	55	lsa_ntoh_body(void n, void h, u16 len)
f45fd316	56	{
c15e5690 OZ	57	u32 *nid = n;
c15e5690 OZ	58	u32 *hid = h;
70945cb6	59	uint i;
f45fd316	60
c15e5690 OZ	61	for (i = 0; i < (len / sizeof(u32)); i++)
	62	hid[i] = ntohl(nid[i]);
	63	}
4e5fb4b6	64	#endif /* little endian */
f45fd316	65
70945cb6	66
70945cb6 OZ	67	int
70945cb6 OZ	68	lsa_flooding_allowed(u32 type, u32 domain, struct ospf_iface *ifa)
742029eb	69	{
70945cb6 OZ	70	/* Handle inactive vlinks */
	71	if (ifa->state == OSPF_IS_DOWN)
	72	return 0;
742029eb	73
70945cb6 OZ	74	/* 4.5.2 (Case 2) */
	75	switch (LSA_SCOPE(type))
	76	{
	77	case LSA_SCOPE_LINK:
	78	return ifa->iface_id == domain;
	79
	80	case LSA_SCOPE_AREA:
	81	return ifa->oa->areaid == domain;
	82
	83	case LSA_SCOPE_AS:
	84	if (ifa->type == OSPF_IT_VLINK)
	85	return 0;
	86	if (!oa_is_ext(ifa->oa))
	87	return 0;
	88	return 1;
	89
	90	default:
	91	log(L_ERR "OSPF: LSA with invalid scope");
	92	return 0;
	93	}
	94	}
	95
5a50a989 OZ	96	int
	97	lsa_is_acceptable(u32 type, struct ospf_neighbor n, struct ospf_proto p)
	98	{
	99	if (ospf_is_v2(p))
	100	{
	101	if (type == LSA_T_NSSA)
	102	return !!(n->options & OPT_N);
	103
	104	if (lsa_is_opaque(type))
	105	return !!(n->options & OPT_O);
	106
	107	return 1;
	108	}
	109	else
	110	{
	111	/*
	112	* There should be check whether receiving router understands that type
	113	* of LSA (for LSA types with U-bit == 0). But as we do not support any
	114	* optional LSA types, this is not needed yet.
	115	*/
	116
	117	return 1;
	118	}
	119	}
70945cb6 OZ	120
	121	static int
	122	unknown_lsa_type(u32 type)
	123	{
	124	switch (type)
	125	{
	126	case LSA_T_RT:
	127	case LSA_T_NET:
	128	case LSA_T_SUM_NET:
	129	case LSA_T_SUM_RT:
	130	case LSA_T_EXT:
	131	case LSA_T_NSSA:
	132	case LSA_T_LINK:
	133	case LSA_T_PREFIX:
5a50a989 OZ	134	case LSA_T_RI_LINK:
	135	case LSA_T_RI_AREA:
	136	case LSA_T_RI_AS:
70945cb6 OZ	137	return 0;
	138
	139	default:
	140	return 1;
	141	}
	142	}
	143
5a50a989 OZ	144	/* Maps OSPFv2 types to OSPFv3 types */
	145	static const u16 lsa_v2_types[] = {
	146	0, LSA_T_RT, LSA_T_NET, LSA_T_SUM_NET, LSA_T_SUM_RT, LSA_T_EXT, 0, LSA_T_NSSA,
	147	0, LSA_T_OPAQUE_LINK, LSA_T_OPAQUE_AREA, LSA_T_OPAQUE_AS
	148	};
	149
	150	/* Maps OSPFv2 opaque types to OSPFv3 function codes */
	151	static const u16 opaque_lsa_types[] = {
1a2ad348	152	[LSA_OT_GR] = LSA_T_GR,
5a50a989 OZ	153	[LSA_OT_RI] = LSA_T_RI_,
	154	};
	155
	156	/* Maps (subset of) OSPFv3 function codes to OSPFv2 opaque types */
	157	static const u8 opaque_lsa_types_inv[] = {
1a2ad348	158	[LSA_T_GR] = LSA_OT_GR,
5a50a989 OZ	159	[LSA_T_RI_] = LSA_OT_RI,
	160	};
	161
	162	#define LOOKUP(a, i) ({ uint _i = (i); (_i < ARRAY_SIZE(a)) ? a[_i] : 0; })
70945cb6 OZ	163
70945cb6 OZ	164	void
5a50a989	165	lsa_get_type_domain_(u32 type, u32 id, struct ospf_iface ifa, u32 otype, u32 *domain)
70945cb6 OZ	166	{
	167	if (ospf_is_v2(ifa->oa->po))
	168	{
5a50a989 OZ	169	type = type & LSA_T_V2_MASK;
	170	type = LOOKUP(lsa_v2_types, type);
	171
	172	uint code;
	173	if (LSA_FUNCTION(type) == LSA_T_OPAQUE_)
	174	if (code = LOOKUP(opaque_lsa_types, id >> 24))
1a2ad348	175	{
5a50a989	176	type = code \| LSA_UBIT \| LSA_SCOPE(type);
1a2ad348 OZ	177
	178	/* Hack for Grace-LSA: It does not use U-bit for link-scoped LSAs */
	179	if (type == (LSA_T_GR \| LSA_UBIT))
	180	type = LSA_T_GR;
	181	}
70945cb6 OZ	182	}
	183	else
	184	{
	185	/* For unkown LSAs without U-bit change scope to LSA_SCOPE_LINK */
5a50a989 OZ	186	if (unknown_lsa_type(type) && !(type & LSA_UBIT))
5a50a989 OZ	187	type = type & ~LSA_SCOPE_MASK;
70945cb6 OZ	188	}
70945cb6 OZ	189
5a50a989	190	*otype = type;
70945cb6	191
5a50a989	192	switch (LSA_SCOPE(type))
70945cb6 OZ	193	{
	194	case LSA_SCOPE_LINK:
	195	*domain = ifa->iface_id;
	196	return;
	197
	198	case LSA_SCOPE_AREA:
	199	*domain = ifa->oa->areaid;
	200	return;
	201
	202	case LSA_SCOPE_AS:
	203	default:
	204	*domain = 0;
	205	return;
	206	}
	207	}
	208
1a2ad348 OZ	209	int
	210	lsa_is_opaque(u32 type)
	211	{
	212	u32 fn = LSA_FUNCTION(type);
	213	return LOOKUP(opaque_lsa_types_inv, fn) \|\| (fn == LSA_T_OPAQUE_);
	214	}
	215
5a50a989 OZ	216	u32
	217	lsa_get_opaque_type(u32 type)
	218	{
	219	return LOOKUP(opaque_lsa_types_inv, LSA_FUNCTION(type));
	220	}
	221
70945cb6	222
061ab802	223	void
77edab64	224	lsa_generate_checksum(struct ospf_lsa_header lsa, const u8 body)
061ab802	225	{
77edab64 OZ	226	struct fletcher16_context ctx;
	227	struct ospf_lsa_header hdr;
	228	u16 len = lsa->length;
061ab802	229
f9c799a0	230	/*
77edab64 OZ	231	* lsa and body are in the host order, we need to compute Fletcher-16 checksum
	232	* for data in the network order. We also skip the initial age field.
	233	*/
394acced	234
77edab64 OZ	235	lsa_hton_hdr(lsa, &hdr);
77edab64 OZ	236	hdr.checksum = 0;
2e10a170	237
77edab64 OZ	238	fletcher16_init(&ctx);
	239	fletcher16_update(&ctx, (u8 *) &hdr + 2, sizeof(struct ospf_lsa_header) - 2);
	240	fletcher16_update_n32(&ctx, body, len - sizeof(struct ospf_lsa_header));
	241	lsa->checksum = fletcher16_final(&ctx, len, OFFSETOF(struct ospf_lsa_header, checksum));
394acced OF	242	}
394acced OF	243
394acced	244	u16
77edab64	245	lsa_verify_checksum(const void *lsa_n, int lsa_len)
499cb346	246	{
77edab64	247	struct fletcher16_context ctx;
499cb346	248
77edab64	249	/* The whole LSA is at lsa_n in net order, we just skip initial age field */
30d09eb9	250
77edab64 OZ	251	fletcher16_init(&ctx);
77edab64 OZ	252	fletcher16_update(&ctx, (u8 *) lsa_n + 2, lsa_len - 2);
499cb346	253
77edab64	254	return fletcher16_compute(&ctx) == 0;
499cb346 OF	255	}
499cb346 OF	256
77edab64	257
db9fb727 OF	258	int
db9fb727 OF	259	lsa_comp(struct ospf_lsa_header l1, struct ospf_lsa_header l2)
394acced	260	/* Return codes from point of view of l1 */
db9fb727	261	{
2e10a170	262	u32 sn1, sn2;
37282678	263
2e10a170 OF	264	sn1 = l1->sn - LSA_INITSEQNO + 1;
2e10a170 OF	265	sn2 = l2->sn - LSA_INITSEQNO + 1;
37282678	266
2e10a170 OF	267	if (sn1 > sn2)
	268	return CMP_NEWER;
	269	if (sn1 < sn2)
	270	return CMP_OLDER;
ef6f26b4	271
2e10a170 OF	272	if (l1->checksum != l2->checksum)
2e10a170 OF	273	return l1->checksum < l2->checksum ? CMP_OLDER : CMP_NEWER;
ef6f26b4	274
2e10a170 OF	275	if ((l1->age == LSA_MAXAGE) && (l2->age != LSA_MAXAGE))
	276	return CMP_NEWER;
	277	if ((l2->age == LSA_MAXAGE) && (l1->age != LSA_MAXAGE))
	278	return CMP_OLDER;
ef6f26b4	279
2e10a170 OF	280	if (ABS(l1->age - l2->age) > LSA_MAXAGEDIFF)
2e10a170 OF	281	return l1->age < l2->age ? CMP_NEWER : CMP_OLDER;
ef6f26b4 OF	282
ef6f26b4 OF	283	return CMP_SAME;
db9fb727 OF	284	}
db9fb727 OF	285
a6bc04d5	286
1a2ad348 OZ	287	#define LSA_TLV_LENGTH(tlv) \
	288	(sizeof(struct ospf_tlv) + BIRD_ALIGN((tlv)->length, 4))
	289
	290	#define LSA_NEXT_TLV(tlv) \
	291	((struct ospf_tlv ) ((byte ) (tlv) + LSA_TLV_LENGTH(tlv)))
	292
	293	#define LSA_WALK_TLVS(tlv,buf,len) \
	294	for(struct ospf_tlv tlv = (void ) (buf); \
	295	(byte ) tlv < (byte ) (buf) + (len); \
	296	tlv = LSA_NEXT_TLV(tlv))
	297
	298	struct ospf_tlv *
	299	lsa_get_tlv(struct top_hash_entry *en, uint type)
	300	{
	301	LSA_WALK_TLVS(tlv, en->lsa_body, en->lsa.length - HDRLEN)
	302	if (tlv->type == type)
	303	return tlv;
	304
	305	return NULL;
	306	}
	307
	308	int
	309	lsa_validate_tlvs(byte *buf, uint len)
	310	{
	311	byte *pos = buf;
	312	byte *end = buf + len;
	313
	314	while (pos < end)
	315	{
	316	if ((pos + sizeof(struct ospf_tlv)) > end)
	317	return 0;
	318
	319	struct ospf_tlv tlv = (void ) pos;
	320	uint len = LSA_TLV_LENGTH(tlv);
	321
	322	if ((pos + len) > end)
	323	return 0;
	324
	325	pos += len;
	326	}
	327
	328	return 1;
	329	}
	330
	331
70945cb6 OZ	332	static inline int
70945cb6 OZ	333	lsa_walk_rt2(struct ospf_lsa_rt_walk *rt)
a6bc04d5	334	{
70945cb6	335	if (rt->buf >= rt->bufend)
a6bc04d5 OZ	336	return 0;
a6bc04d5 OZ	337
70945cb6 OZ	338	struct ospf_lsa_rt2_link *l = rt->buf;
70945cb6 OZ	339	rt->buf += sizeof(struct ospf_lsa_rt2_link) + l->no_tos * sizeof(struct ospf_lsa_rt2_tos);
a6bc04d5	340
70945cb6 OZ	341	rt->type = l->type;
	342	rt->metric = l->metric;
	343	rt->id = l->id;
	344	rt->data = l->data;
	345	return 1;
	346	}
a6bc04d5	347
70945cb6 OZ	348	static inline int
	349	lsa_walk_rt3(struct ospf_lsa_rt_walk *rt)
	350	{
	351	while (rt->buf >= rt->bufend)
a6bc04d5	352	{
70945cb6 OZ	353	rt->en = ospf_hash_find_rt3_next(rt->en);
70945cb6 OZ	354	if (!rt->en)
a6bc04d5	355	return 0;
70945cb6 OZ	356
	357	rt->buf = rt->en->lsa_body;
	358	rt->bufend = rt->buf + rt->en->lsa.length - sizeof(struct ospf_lsa_header);
	359	rt->buf += sizeof(struct ospf_lsa_rt);
a6bc04d5	360	}
70945cb6 OZ	361
	362	struct ospf_lsa_rt3_link *l = rt->buf;
	363	rt->buf += sizeof(struct ospf_lsa_rt3_link);
	364
	365	rt->type = l->type;
	366	rt->metric = l->metric;
	367	rt->lif = l->lif;
	368	rt->nif = l->nif;
	369	rt->id = l->id;
a6bc04d5 OZ	370	return 1;
	371	}
	372
70945cb6 OZ	373	void
	374	lsa_walk_rt_init(struct ospf_proto p, struct top_hash_entry act, struct ospf_lsa_rt_walk *rt)
	375	{
	376	rt->ospf2 = ospf_is_v2(p);
	377	rt->id = rt->data = rt->lif = rt->nif = 0;
	378
	379	if (rt->ospf2)
	380	rt->en = act;
	381	else
	382	rt->en = ospf_hash_find_rt3_first(p->gr, act->domain, act->lsa.rt);
	383
	384	rt->buf = rt->en->lsa_body;
	385	rt->bufend = rt->buf + rt->en->lsa.length - sizeof(struct ospf_lsa_header);
	386	rt->buf += sizeof(struct ospf_lsa_rt);
	387	}
	388
	389	int
	390	lsa_walk_rt(struct ospf_lsa_rt_walk *rt)
	391	{
	392	return rt->ospf2 ? lsa_walk_rt2(rt) : lsa_walk_rt3(rt);
	393	}
	394
	395
	396	void
d3f4f92b	397	lsa_parse_sum_net(struct top_hash_entry en, int ospf2, int af, net_addr net, u8 pxopts, u32 metric)
70945cb6 OZ	398	{
	399	if (ospf2)
	400	{
4a3f5b36	401	uint opts = lsa_get_options(&en->lsa);
70945cb6	402	struct ospf_lsa_sum2 *ls = en->lsa_body;
fe9f1a6d	403	net_fill_ip4(net, ip4_from_u32(en->lsa.id & ls->netmask), u32_masklen(ls->netmask));
4a3f5b36	404	*pxopts = (opts & OPT_DN) ? OPT_PX_DN : 0;
70945cb6 OZ	405	*metric = ls->metric & LSA_METRIC_MASK;
	406	}
	407	else
	408	{
	409	struct ospf_lsa_sum3_net *ls = en->lsa_body;
d3f4f92b	410	ospf3_get_prefix(ls->prefix, af, net, pxopts, NULL);
70945cb6 OZ	411	*metric = ls->metric & LSA_METRIC_MASK;
	412	}
	413	}
	414
	415	void
	416	lsa_parse_sum_rt(struct top_hash_entry en, int ospf2, u32 drid, u32 metric, u32 options)
	417	{
	418	if (ospf2)
	419	{
	420	struct ospf_lsa_sum2 *ls = en->lsa_body;
	421	*drid = en->lsa.id;
	422	*metric = ls->metric & LSA_METRIC_MASK;
	423	*options = 0;
	424	}
	425	else
	426	{
	427	struct ospf_lsa_sum3_rt *ls = en->lsa_body;
	428	*drid = ls->drid;
	429	*metric = ls->metric & LSA_METRIC_MASK;
	430	*options = ls->options & LSA_OPTIONS_MASK;
	431	}
	432	}
	433
	434	void
d3f4f92b	435	lsa_parse_ext(struct top_hash_entry en, int ospf2, int af, struct ospf_lsa_ext_local rt)
70945cb6 OZ	436	{
	437	if (ospf2)
	438	{
	439	struct ospf_lsa_ext2 *ext = en->lsa_body;
fe9f1a6d OZ	440	net_fill_ip4(&rt->net,
	441	ip4_from_u32(en->lsa.id & ext->netmask),
	442	u32_masklen(ext->netmask));
70945cb6 OZ	443	rt->pxopts = 0;
	444	rt->metric = ext->metric & LSA_METRIC_MASK;
	445	rt->ebit = ext->metric & LSA_EXT2_EBIT;
	446
	447	rt->fbit = ext->fwaddr;
	448	rt->fwaddr = ipa_from_u32(ext->fwaddr);
	449
	450	rt->tag = ext->tag;
	451	rt->propagate = lsa_get_options(&en->lsa) & OPT_P;
4a3f5b36	452	rt->downwards = lsa_get_options(&en->lsa) & OPT_DN;
70945cb6 OZ	453	}
	454	else
	455	{
	456	struct ospf_lsa_ext3 *ext = en->lsa_body;
d3f4f92b	457	u32 *buf = ospf3_get_prefix(ext->rest, af, &rt->net, &rt->pxopts, NULL);
70945cb6 OZ	458	rt->metric = ext->metric & LSA_METRIC_MASK;
	459	rt->ebit = ext->metric & LSA_EXT3_EBIT;
	460
	461	rt->fbit = ext->metric & LSA_EXT3_FBIT;
	462	if (rt->fbit)
d3f4f92b	463	buf = ospf3_get_addr(buf, af, &rt->fwaddr);
742029eb	464	else
70945cb6 OZ	465	rt->fwaddr = IPA_NONE;
	466
	467	rt->tag = (ext->metric & LSA_EXT3_TBIT) ? *buf++ : 0;
	468	rt->propagate = rt->pxopts & OPT_PX_P;
4a3f5b36	469	rt->downwards = rt->pxopts & OPT_PX_DN;
70945cb6 OZ	470	}
	471	}
	472
70945cb6	473
a6bc04d5	474	static int
70945cb6	475	lsa_validate_rt2(struct ospf_lsa_header lsa, struct ospf_lsa_rt body)
a6bc04d5	476	{
70945cb6 OZ	477	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_rt)))
	478	return 0;
	479
	480	uint i = 0;
	481	void *buf = body;
	482	void *bufend = buf + lsa->length - HDRLEN;
	483	buf += sizeof(struct ospf_lsa_rt);
	484
	485	while (buf < bufend)
	486	{
	487	struct ospf_lsa_rt2_link *l = buf;
	488	buf += sizeof(struct ospf_lsa_rt2_link) + l->no_tos * sizeof(struct ospf_lsa_rt2_tos);
	489	i++;
	490
	491	if (buf > bufend)
	492	return 0;
	493
	494	if (!((l->type == LSART_PTP) \|\|
	495	(l->type == LSART_NET) \|\|
	496	(l->type == LSART_STUB) \|\|
	497	(l->type == LSART_VLNK)))
	498	return 0;
	499	}
	500
	501	if ((body->options & LSA_RT2_LINKS) != i)
a6bc04d5 OZ	502	return 0;
	503
	504	return 1;
	505	}
	506
a6bc04d5 OZ	507
a6bc04d5 OZ	508	static int
70945cb6	509	lsa_validate_rt3(struct ospf_lsa_header lsa, struct ospf_lsa_rt body)
a6bc04d5	510	{
70945cb6	511	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_rt)))
a6bc04d5 OZ	512	return 0;
a6bc04d5 OZ	513
70945cb6 OZ	514	void *buf = body;
	515	void *bufend = buf + lsa->length - HDRLEN;
	516	buf += sizeof(struct ospf_lsa_rt);
	517
	518	while (buf < bufend)
	519	{
	520	struct ospf_lsa_rt3_link *l = buf;
	521	buf += sizeof(struct ospf_lsa_rt3_link);
	522
	523	if (buf > bufend)
	524	return 0;
	525
	526	if (!((l->type == LSART_PTP) \|\|
	527	(l->type == LSART_NET) \|\|
	528	(l->type == LSART_VLNK)))
	529	return 0;
	530	}
	531	return 1;
	532	}
	533
	534	static int
	535	lsa_validate_net(struct ospf_lsa_header lsa, struct ospf_lsa_net body UNUSED)
	536	{
	537	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_net)))
a6bc04d5 OZ	538	return 0;
	539
	540	return 1;
	541	}
a6bc04d5 OZ	542
a6bc04d5 OZ	543	static int
70945cb6	544	lsa_validate_sum2(struct ospf_lsa_header lsa, struct ospf_lsa_sum2 body)
a6bc04d5	545	{
70945cb6	546	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum2)))
a6bc04d5 OZ	547	return 0;
	548
	549	/* First field should have TOS = 0, we ignore other TOS fields */
70945cb6	550	if ((body->metric & LSA_SUM2_TOS) != 0)
a6bc04d5 OZ	551	return 0;
	552
	553	return 1;
	554	}
	555
a6bc04d5 OZ	556	static inline int
	557	pxlen(u32 *buf)
	558	{
	559	return *buf >> 24;
	560	}
	561
	562	static int
70945cb6	563	lsa_validate_sum3_net(struct ospf_lsa_header lsa, struct ospf_lsa_sum3_net body)
a6bc04d5	564	{
70945cb6	565	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_sum3_net) + 4))
a6bc04d5 OZ	566	return 0;
	567
	568	u8 pxl = pxlen(body->prefix);
fe9f1a6d	569	if (pxl > IP6_MAX_PREFIX_LENGTH)
a6bc04d5 OZ	570	return 0;
a6bc04d5 OZ	571
742029eb	572	if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum3_net) +
a6bc04d5 OZ	573	IPV6_PREFIX_SPACE(pxl)))
	574	return 0;
	575
	576	return 1;
	577	}
	578
70945cb6	579	static int
3e236955	580	lsa_validate_sum3_rt(struct ospf_lsa_header lsa, struct ospf_lsa_sum3_rt body UNUSED)
70945cb6 OZ	581	{
	582	if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_sum3_rt)))
	583	return 0;
	584
	585	return 1;
	586	}
a6bc04d5 OZ	587
a6bc04d5 OZ	588	static int
70945cb6	589	lsa_validate_ext2(struct ospf_lsa_header lsa, struct ospf_lsa_ext2 body)
a6bc04d5	590	{
70945cb6 OZ	591	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext2)))
	592	return 0;
	593
	594	/* First field should have TOS = 0, we ignore other TOS fields */
	595	if ((body->metric & LSA_EXT2_TOS) != 0)
a6bc04d5 OZ	596	return 0;
	597
	598	return 1;
	599	}
	600
	601	static int
70945cb6	602	lsa_validate_ext3(struct ospf_lsa_header lsa, struct ospf_lsa_ext3 body)
a6bc04d5	603	{
70945cb6	604	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_ext3) + 4))
a6bc04d5 OZ	605	return 0;
	606
	607	u8 pxl = pxlen(body->rest);
fe9f1a6d	608	if (pxl > IP6_MAX_PREFIX_LENGTH)
a6bc04d5 OZ	609	return 0;
	610
	611	int len = IPV6_PREFIX_SPACE(pxl);
d7661fbe	612	if (body->metric & LSA_EXT3_FBIT) // forwarding address
a6bc04d5	613	len += 16;
70945cb6	614	if (body->metric & LSA_EXT3_TBIT) // route tag
a6bc04d5 OZ	615	len += 4;
	616	if (*body->rest & 0xFFFF) // referenced LS type field
	617	len += 4;
	618
70945cb6	619	if (lsa->length != (HDRLEN + sizeof(struct ospf_lsa_ext3) + len))
a6bc04d5 OZ	620	return 0;
	621
	622	return 1;
	623	}
	624
	625	static int
70945cb6	626	lsa_validate_pxlist(struct ospf_lsa_header lsa, u32 pxcount, uint offset, u8 pbuf)
a6bc04d5	627	{
70945cb6	628	uint bound = lsa->length - HDRLEN - 4;
a6bc04d5 OZ	629	u32 i;
	630
	631	for (i = 0; i < pxcount; i++)
	632	{
	633	if (offset > bound)
	634	return 0;
	635
	636	u8 pxl = pxlen((u32 *) (pbuf + offset));
fe9f1a6d	637	if (pxl > IP6_MAX_PREFIX_LENGTH)
a6bc04d5	638	return 0;
742029eb	639
a6bc04d5 OZ	640	offset += IPV6_PREFIX_SPACE(pxl);
	641	}
	642
	643	if (lsa->length != (HDRLEN + offset))
	644	return 0;
	645
	646	return 1;
	647	}
	648
	649	static int
	650	lsa_validate_link(struct ospf_lsa_header lsa, struct ospf_lsa_link body)
	651	{
	652	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_link)))
	653	return 0;
	654
	655	return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_link), (u8 *) body);
	656	}
	657
	658	static int
	659	lsa_validate_prefix(struct ospf_lsa_header lsa, struct ospf_lsa_prefix body)
	660	{
	661	if (lsa->length < (HDRLEN + sizeof(struct ospf_lsa_prefix)))
	662	return 0;
	663
	664	return lsa_validate_pxlist(lsa, body->pxcount, sizeof(struct ospf_lsa_prefix), (u8 *) body);
	665	}
	666
1a2ad348 OZ	667	static int
	668	lsa_validate_gr(struct ospf_lsa_header lsa, void body)
	669	{
	670	return lsa_validate_tlvs(body, lsa->length - HDRLEN);
	671	}
	672
5a50a989 OZ	673	static int
	674	lsa_validate_ri(struct ospf_lsa_header lsa UNUSED, struct ospf_lsa_net body UNUSED)
	675	{
	676	/*
	677	* There should be proper validation. But we do not really process RI LSAs, so
	678	* we can just accept them like another unknown opaque LSAs.
	679	*/
	680
	681	return 1;
	682	}
	683
a6bc04d5 OZ	684
	685	/**
	686	* lsa_validate - check whether given LSA is valid
	687	* @lsa: LSA header
af678af0 OZ	688	* @lsa_type: internal LSA type (%LSA_T_xxx)
af678af0 OZ	689	* @ospf2: %true for OSPFv2, %false for OSPFv3
a6bc04d5 OZ	690	* @body: pointer to LSA body
	691	*
	692	* Checks internal structure of given LSA body (minimal length,
	693	* consistency). Returns true if valid.
	694	*/
a6bc04d5	695	int
70945cb6	696	lsa_validate(struct ospf_lsa_header lsa, u32 lsa_type, int ospf2, void body)
a6bc04d5	697	{
70945cb6 OZ	698	if (ospf2)
	699	{
	700	switch (lsa_type)
	701	{
	702	case LSA_T_RT:
	703	return lsa_validate_rt2(lsa, body);
	704	case LSA_T_NET:
	705	return lsa_validate_net(lsa, body);
	706	case LSA_T_SUM_NET:
	707	return lsa_validate_sum2(lsa, body);
	708	case LSA_T_SUM_RT:
	709	return lsa_validate_sum2(lsa, body);
	710	case LSA_T_EXT:
	711	case LSA_T_NSSA:
	712	return lsa_validate_ext2(lsa, body);
1a2ad348 OZ	713	case LSA_T_GR:
1a2ad348 OZ	714	return lsa_validate_gr(lsa, body);
5a50a989 OZ	715	case LSA_T_RI_LINK:
	716	case LSA_T_RI_AREA:
	717	case LSA_T_RI_AS:
	718	return lsa_validate_ri(lsa, body);
	719	case LSA_T_OPAQUE_LINK:
	720	case LSA_T_OPAQUE_AREA:
	721	case LSA_T_OPAQUE_AS:
	722	return 1; /* Unknown Opaque LSAs */
70945cb6 OZ	723	default:
	724	return 0; /* Should not happen, unknown LSAs are already rejected */
	725	}
	726	}
	727	else
	728	{
	729	switch (lsa_type)
a6bc04d5 OZ	730	{
a6bc04d5 OZ	731	case LSA_T_RT:
70945cb6	732	return lsa_validate_rt3(lsa, body);
a6bc04d5 OZ	733	case LSA_T_NET:
	734	return lsa_validate_net(lsa, body);
	735	case LSA_T_SUM_NET:
70945cb6	736	return lsa_validate_sum3_net(lsa, body);
a6bc04d5	737	case LSA_T_SUM_RT:
70945cb6	738	return lsa_validate_sum3_rt(lsa, body);
a6bc04d5	739	case LSA_T_EXT:
41b612c3	740	case LSA_T_NSSA:
70945cb6	741	return lsa_validate_ext3(lsa, body);
a6bc04d5 OZ	742	case LSA_T_LINK:
	743	return lsa_validate_link(lsa, body);
	744	case LSA_T_PREFIX:
	745	return lsa_validate_prefix(lsa, body);
1a2ad348 OZ	746	case LSA_T_GR:
1a2ad348 OZ	747	return lsa_validate_gr(lsa, body);
5a50a989 OZ	748	case LSA_T_RI_LINK:
	749	case LSA_T_RI_AREA:
	750	case LSA_T_RI_AS:
	751	return lsa_validate_ri(lsa, body);
a6bc04d5	752	default:
70945cb6	753	return 1; /* Unknown LSAs are OK in OSPFv3 */
a6bc04d5	754	}
85195f1a	755	}
d8852b36	756	}