479 lines
11 KiB
C
479 lines
11 KiB
C
/*
|
|
* BIRD -- OSPF
|
|
*
|
|
* (c) 1999--2004 Ondrej Filip <feela@network.cz>
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
#include "ospf.h"
|
|
|
|
void
|
|
flush_lsa(struct top_hash_entry *en, struct proto_ospf *po)
|
|
{
|
|
struct proto *p = &po->proto;
|
|
|
|
OSPF_TRACE(D_EVENTS,
|
|
"Going to remove node Type: %u, Id: %R, Rt: %R, Age: %u, SN: 0x%x",
|
|
en->lsa.type, en->lsa.id, en->lsa.rt, en->lsa.age, en->lsa.sn);
|
|
s_rem_node(SNODE en);
|
|
if (en->lsa_body != NULL)
|
|
mb_free(en->lsa_body);
|
|
en->lsa_body = NULL;
|
|
ospf_hash_delete(po->gr, en);
|
|
}
|
|
|
|
/**
|
|
* ospf_age
|
|
* @po: ospf protocol
|
|
*
|
|
* This function is periodicaly invoked from ospf_disp(). It computes the new
|
|
* age of all LSAs and old (@age is higher than %LSA_MAXAGE) LSAs are flushed
|
|
* whenever possible. If an LSA originated by the router itself is older
|
|
* than %LSREFRESHTIME a new instance is originated.
|
|
*
|
|
* The RFC says that a router should check the checksum of every LSA to detect
|
|
* hardware problems. BIRD does not do this to minimalize CPU utilization.
|
|
*
|
|
* If routing table calculation is scheduled, it also invalidates the old routing
|
|
* table calculation results.
|
|
*/
|
|
void
|
|
ospf_age(struct proto_ospf *po)
|
|
{
|
|
struct proto *p = &po->proto;
|
|
struct top_hash_entry *en, *nxt;
|
|
int flush = can_flush_lsa(po);
|
|
|
|
if (po->cleanup) OSPF_TRACE(D_EVENTS, "Running ospf_age cleanup");
|
|
|
|
WALK_SLIST_DELSAFE(en, nxt, po->lsal)
|
|
{
|
|
if (po->cleanup)
|
|
{
|
|
en->color = OUTSPF;
|
|
en->dist = LSINFINITY;
|
|
en->nhi = NULL;
|
|
en->nh = IPA_NONE;
|
|
en->lb = IPA_NONE;
|
|
DBG("Infinitying Type: %u, Id: %R, Rt: %R\n", en->lsa.type,
|
|
en->lsa.id, en->lsa.rt);
|
|
}
|
|
if (en->lsa.age == LSA_MAXAGE)
|
|
{
|
|
if (flush)
|
|
flush_lsa(en, po);
|
|
continue;
|
|
}
|
|
if ((en->lsa.rt == p->cf->global->router_id) &&(en->lsa.age >=
|
|
LSREFRESHTIME))
|
|
{
|
|
OSPF_TRACE(D_EVENTS, "Refreshing my LSA: Type: %u, Id: %R, Rt: %R",
|
|
en->lsa.type, en->lsa.id, en->lsa.rt);
|
|
en->lsa.sn++;
|
|
en->lsa.age = 0;
|
|
en->inst_t = now;
|
|
en->ini_age = 0;
|
|
lsasum_calculate(&en->lsa, en->lsa_body);
|
|
ospf_lsupd_flood(NULL, NULL, &en->lsa, NULL, en->oa, 1);
|
|
continue;
|
|
}
|
|
if ((en->lsa.age = (en->ini_age + (now - en->inst_t))) >= LSA_MAXAGE)
|
|
{
|
|
if (flush)
|
|
{
|
|
flush_lsa(en, po);
|
|
schedule_rtcalc(po);
|
|
}
|
|
else
|
|
en->lsa.age = LSA_MAXAGE;
|
|
}
|
|
}
|
|
po->cleanup = 0;
|
|
}
|
|
|
|
void
|
|
htonlsah(struct ospf_lsa_header *h, struct ospf_lsa_header *n)
|
|
{
|
|
n->age = htons(h->age);
|
|
n->options = h->options;
|
|
n->type = h->type;
|
|
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
|
|
ntohlsah(struct ospf_lsa_header *n, struct ospf_lsa_header *h)
|
|
{
|
|
h->age = ntohs(n->age);
|
|
h->options = n->options;
|
|
h->type = n->type;
|
|
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
|
|
htonlsab(void *h, void *n, u8 type, u16 len)
|
|
{
|
|
unsigned int i;
|
|
switch (type)
|
|
{
|
|
case LSA_T_RT:
|
|
{
|
|
struct ospf_lsa_rt *hrt, *nrt;
|
|
struct ospf_lsa_rt_link *hrtl, *nrtl;
|
|
u16 links;
|
|
|
|
nrt = n;
|
|
hrt = h;
|
|
links = hrt->links;
|
|
|
|
nrt->veb.byte = hrt->veb.byte;
|
|
nrt->padding = 0;
|
|
nrt->links = htons(hrt->links);
|
|
nrtl = (struct ospf_lsa_rt_link *) (nrt + 1);
|
|
hrtl = (struct ospf_lsa_rt_link *) (hrt + 1);
|
|
for (i = 0; i < links; i++)
|
|
{
|
|
(nrtl + i)->id = htonl((hrtl + i)->id);
|
|
(nrtl + i)->data = htonl((hrtl + i)->data);
|
|
(nrtl + i)->type = (hrtl + i)->type;
|
|
(nrtl + i)->notos = (hrtl + i)->notos;
|
|
(nrtl + i)->metric = htons((hrtl + i)->metric);
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_NET:
|
|
{
|
|
u32 *hid, *nid;
|
|
|
|
nid = n;
|
|
hid = h;
|
|
|
|
for (i = 0; i < (len / sizeof(u32)); i++)
|
|
{
|
|
*(nid + i) = htonl(*(hid + i));
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_SUM_NET:
|
|
case LSA_T_SUM_RT:
|
|
{
|
|
struct ospf_lsa_sum *hs, *ns;
|
|
union ospf_lsa_sum_tm *hn, *nn;
|
|
|
|
hs = h;
|
|
ns = n;
|
|
|
|
ns->netmask = hs->netmask;
|
|
ipa_hton(ns->netmask);
|
|
|
|
hn = (union ospf_lsa_sum_tm *) (hs + 1);
|
|
nn = (union ospf_lsa_sum_tm *) (ns + 1);
|
|
|
|
for (i = 0; i < ((len - sizeof(struct ospf_lsa_sum)) /
|
|
sizeof(union ospf_lsa_sum_tm)); i++)
|
|
{
|
|
(nn + i)->metric = htonl((hn + i)->metric);
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_EXT:
|
|
{
|
|
struct ospf_lsa_ext *he, *ne;
|
|
struct ospf_lsa_ext_tos *ht, *nt;
|
|
|
|
he = h;
|
|
ne = n;
|
|
|
|
ne->netmask = he->netmask;
|
|
ipa_hton(ne->netmask);
|
|
|
|
ht = (struct ospf_lsa_ext_tos *) (he + 1);
|
|
nt = (struct ospf_lsa_ext_tos *) (ne + 1);
|
|
|
|
for (i = 0; i < ((len - sizeof(struct ospf_lsa_ext)) /
|
|
sizeof(struct ospf_lsa_ext_tos)); i++)
|
|
{
|
|
(nt + i)->etm.metric = htonl((ht + i)->etm.metric);
|
|
(nt + i)->fwaddr = (ht + i)->fwaddr;
|
|
ipa_hton((nt + i)->fwaddr);
|
|
(nt + i)->tag = htonl((ht + i)->tag);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
bug("(hton): Unknown LSA");
|
|
}
|
|
};
|
|
|
|
void
|
|
ntohlsab(void *n, void *h, u8 type, u16 len)
|
|
{
|
|
unsigned int i;
|
|
switch (type)
|
|
{
|
|
case LSA_T_RT:
|
|
{
|
|
struct ospf_lsa_rt *hrt, *nrt;
|
|
struct ospf_lsa_rt_link *hrtl, *nrtl;
|
|
u16 links;
|
|
|
|
nrt = n;
|
|
hrt = h;
|
|
|
|
hrt->veb.byte = nrt->veb.byte;
|
|
hrt->padding = 0;
|
|
links = hrt->links = ntohs(nrt->links);
|
|
nrtl = (struct ospf_lsa_rt_link *) (nrt + 1);
|
|
hrtl = (struct ospf_lsa_rt_link *) (hrt + 1);
|
|
for (i = 0; i < links; i++)
|
|
{
|
|
(hrtl + i)->id = ntohl((nrtl + i)->id);
|
|
(hrtl + i)->data = ntohl((nrtl + i)->data);
|
|
(hrtl + i)->type = (nrtl + i)->type;
|
|
(hrtl + i)->notos = (nrtl + i)->notos;
|
|
(hrtl + i)->metric = ntohs((nrtl + i)->metric);
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_NET:
|
|
{
|
|
u32 *hid, *nid;
|
|
|
|
hid = h;
|
|
nid = n;
|
|
|
|
for (i = 0; i < (len / sizeof(u32)); i++)
|
|
{
|
|
*(hid + i) = ntohl(*(nid + i));
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_SUM_NET:
|
|
case LSA_T_SUM_RT:
|
|
{
|
|
struct ospf_lsa_sum *hs, *ns;
|
|
union ospf_lsa_sum_tm *hn, *nn;
|
|
|
|
hs = h;
|
|
ns = n;
|
|
|
|
hs->netmask = ns->netmask;
|
|
ipa_ntoh(hs->netmask);
|
|
|
|
hn = (union ospf_lsa_sum_tm *) (hs + 1);
|
|
nn = (union ospf_lsa_sum_tm *) (ns + 1);
|
|
|
|
for (i = 0; i < ((len - sizeof(struct ospf_lsa_sum)) /
|
|
sizeof(union ospf_lsa_sum_tm)); i++)
|
|
{
|
|
(hn + i)->metric = ntohl((nn + i)->metric);
|
|
}
|
|
break;
|
|
}
|
|
case LSA_T_EXT:
|
|
{
|
|
struct ospf_lsa_ext *he, *ne;
|
|
struct ospf_lsa_ext_tos *ht, *nt;
|
|
|
|
he = h;
|
|
ne = n;
|
|
|
|
he->netmask = ne->netmask;
|
|
ipa_ntoh(he->netmask);
|
|
|
|
ht = (struct ospf_lsa_ext_tos *) (he + 1);
|
|
nt = (struct ospf_lsa_ext_tos *) (ne + 1);
|
|
|
|
for (i = 0; i < ((len - sizeof(struct ospf_lsa_ext)) /
|
|
sizeof(struct ospf_lsa_ext_tos)); i++)
|
|
{
|
|
(ht + i)->etm.metric = ntohl((nt + i)->etm.metric);
|
|
(ht + i)->fwaddr = (nt + i)->fwaddr;
|
|
ipa_ntoh((ht + i)->fwaddr);
|
|
(ht + i)->tag = ntohl((nt + i)->tag);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
bug("(ntoh): Unknown LSA");
|
|
}
|
|
};
|
|
|
|
#define MODX 4102 /* larges signed value without overflow */
|
|
|
|
/* Fletcher Checksum -- Refer to RFC1008. */
|
|
#define MODX 4102
|
|
#define LSA_CHECKSUM_OFFSET 15
|
|
|
|
/* FIXME This is VERY uneficient, I have huge endianity problems */
|
|
void
|
|
lsasum_calculate(struct ospf_lsa_header *h, void *body)
|
|
{
|
|
u16 length;
|
|
|
|
length = h->length;
|
|
|
|
htonlsah(h, h);
|
|
htonlsab(body, body, h->type, length - sizeof(struct ospf_lsa_header));
|
|
|
|
(void) lsasum_check(h, body);
|
|
|
|
ntohlsah(h, h);
|
|
ntohlsab(body, body, h->type, length - sizeof(struct ospf_lsa_header));
|
|
}
|
|
|
|
/*
|
|
* Note, that this function expects that LSA is in big endianity
|
|
* It also returns value in big endian
|
|
*/
|
|
u16
|
|
lsasum_check(struct ospf_lsa_header *h, void *body)
|
|
{
|
|
u8 *sp, *ep, *p, *q, *b;
|
|
int c0 = 0, c1 = 0;
|
|
int x, y;
|
|
u16 length;
|
|
|
|
b = body;
|
|
sp = (char *) &h->options;
|
|
length = ntohs(h->length) - 2;
|
|
h->checksum = 0;
|
|
|
|
for (ep = sp + length; sp < ep; sp = q)
|
|
{ /* Actually MODX is very large, do we need the for-cyclus? */
|
|
q = sp + MODX;
|
|
if (q > ep)
|
|
q = ep;
|
|
for (p = sp; p < q; p++)
|
|
{
|
|
/*
|
|
* I count with bytes from header and than from body
|
|
* but if there is no body, it's appended to header
|
|
* (probably checksum in update receiving) and I go on
|
|
* after header
|
|
*/
|
|
if ((b == NULL) || (p < (u8 *) (h + 1)))
|
|
{
|
|
c0 += *p;
|
|
}
|
|
else
|
|
{
|
|
c0 += *(b + (p - sp) - sizeof(struct ospf_lsa_header) + 2);
|
|
}
|
|
|
|
c1 += c0;
|
|
}
|
|
c0 %= 255;
|
|
c1 %= 255;
|
|
}
|
|
|
|
x = ((length - LSA_CHECKSUM_OFFSET) * c0 - c1) % 255;
|
|
if (x <= 0)
|
|
x += 255;
|
|
y = 510 - c0 - x;
|
|
if (y > 255)
|
|
y -= 255;
|
|
|
|
((u8 *) & h->checksum)[0] = x;
|
|
((u8 *) & h->checksum)[1] = y;
|
|
return h->checksum;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* lsa_install_new - install new LSA into database
|
|
* @lsa: LSA header
|
|
* @body: pointer to LSA body
|
|
* @oa: current ospf_area
|
|
*
|
|
* This function ensures installing new LSA into LSA database. Old instance is
|
|
* replaced. Several actions are taken to detect if new routing table
|
|
* calculation is necessary. This is described in 13.2 of RFC 2328.
|
|
*/
|
|
struct top_hash_entry *
|
|
lsa_install_new(struct ospf_lsa_header *lsa, void *body, struct ospf_area *oa)
|
|
{
|
|
/* LSA can be temporarrily, but body must be mb_allocated. */
|
|
int change = 0;
|
|
unsigned i;
|
|
struct top_hash_entry *en;
|
|
struct proto_ospf *po = oa->po;
|
|
|
|
if ((en = ospf_hash_find_header(po->gr, oa->areaid, lsa)) == NULL)
|
|
{
|
|
en = ospf_hash_get_header(po->gr, oa, lsa);
|
|
change = 1;
|
|
}
|
|
else
|
|
{
|
|
if ((en->lsa.length != lsa->length) || (en->lsa.options != lsa->options)
|
|
|| ((en->lsa.age == LSA_MAXAGE) || (lsa->age == LSA_MAXAGE)))
|
|
change = 1;
|
|
else
|
|
{
|
|
u8 *k = en->lsa_body, *l = body;
|
|
for (i = 0; i < (lsa->length - sizeof(struct ospf_lsa_header)); i++)
|
|
{
|
|
if (*(k + i) != *(l + i))
|
|
{
|
|
change = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
s_rem_node(SNODE en);
|
|
}
|
|
|
|
DBG("Inst lsa: Id: %R, Rt: %R, Type: %u, Age: %u, Sum: %u, Sn: 0x%x\n",
|
|
lsa->id, lsa->rt, lsa->type, lsa->age, lsa->checksum, lsa->sn);
|
|
|
|
s_add_tail(&po->lsal, SNODE en);
|
|
en->inst_t = now;
|
|
if (en->lsa_body != NULL)
|
|
mb_free(en->lsa_body);
|
|
en->lsa_body = body;
|
|
memcpy(&en->lsa, lsa, sizeof(struct ospf_lsa_header));
|
|
en->ini_age = en->lsa.age;
|
|
|
|
if (change)
|
|
{
|
|
schedule_rtcalc(po);
|
|
}
|
|
|
|
return en;
|
|
}
|