mirror of
https://gitlab.nic.cz/labs/bird.git
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3b16080c97
Origination of summary LSA works. Routing table calculation works. Virtual links works. Well, I hope, OSPF is fully compatible with RFC2328!!!!
492 lines
11 KiB
C
492 lines
11 KiB
C
/*
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* BIRD -- OSPF
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*
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* (c) 1999--2004 Ondrej Filip <feela@network.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#include "ospf.h"
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void
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flush_lsa(struct top_hash_entry *en, struct ospf_area *oa)
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{
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struct proto *p = &oa->po->proto;
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OSPF_TRACE(D_EVENTS,
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"Going to remove node Type: %u, Id: %I, Rt: %I, Age: %u, SN: 0x%x",
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en->lsa.type, en->lsa.id, en->lsa.rt, en->lsa.age, en->lsa.sn);
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s_rem_node(SNODE en);
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if (en->lsa_body != NULL)
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mb_free(en->lsa_body);
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en->lsa_body = NULL;
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ospf_hash_delete(oa->gr, en);
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}
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/**
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* ospf_age
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* @oa: ospf area
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*
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* This function is periodicaly invoked from area_disp(). It computes the new
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* age of all LSAs and old (@age is higher than %LSA_MAXAGE) LSAs are flushed
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* whenever possible. If an LSA originated by the router itself is older
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* than %LSREFRESHTIME a new instance is originated.
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*
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* The RFC says that a router should check the checksum of every LSA to detect
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* hardware problems. BIRD does not do this to minimalize CPU utilization.
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*
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* If routing table calculation is scheduled, it also invalidates the old routing
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* table calculation results.
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*/
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void
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ospf_age(struct ospf_area *oa)
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{
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struct proto *p = &oa->po->proto;
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struct proto_ospf *po = (struct proto_ospf *) p;
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struct top_hash_entry *en, *nxt;
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int flush = can_flush_lsa(oa);
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int cleanup = (oa->rt && (oa->rt->dist != LSINFINITY));
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if (cleanup) OSPF_TRACE(D_EVENTS, "Running ospf_age cleanup");
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WALK_SLIST_DELSAFE(en, nxt, oa->lsal)
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{
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if (cleanup)
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{
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en->color = OUTSPF;
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en->dist = LSINFINITY;
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en->nhi = NULL;
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en->nh = IPA_NONE;
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en->lb = IPA_NONE;
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DBG("Infinitying Type: %u, Id: %I, Rt: %I\n", en->lsa.type, en->lsa.id,
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en->lsa.rt);
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}
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if (en->lsa.age == LSA_MAXAGE)
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{
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if (flush)
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flush_lsa(en, oa);
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continue;
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}
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if ((en->lsa.rt == p->cf->global->router_id) &&(en->lsa.age >=
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LSREFRESHTIME))
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{
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OSPF_TRACE(D_EVENTS, "Refreshing my LSA: Type: %u, Id: %I, Rt: %I",
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en->lsa.type, en->lsa.id, en->lsa.rt);
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en->lsa.sn++;
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en->lsa.age = 0;
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en->inst_t = now;
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en->ini_age = 0;
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lsasum_calculate(&en->lsa, en->lsa_body);
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ospf_lsupd_flood(NULL, NULL, &en->lsa, NULL, oa, 1);
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continue;
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}
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if ((en->lsa.age = (en->ini_age + (now - en->inst_t))) >= LSA_MAXAGE)
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{
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if (flush)
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{
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flush_lsa(en, oa);
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schedule_rtcalc(po);
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}
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else
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en->lsa.age = LSA_MAXAGE;
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}
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}
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}
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void
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htonlsah(struct ospf_lsa_header *h, struct ospf_lsa_header *n)
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{
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n->age = htons(h->age);
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n->options = h->options;
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n->type = h->type;
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n->id = htonl(h->id);
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n->rt = htonl(h->rt);
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n->sn = htonl(h->sn);
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n->checksum = htons(h->checksum);
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n->length = htons(h->length);
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};
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void
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ntohlsah(struct ospf_lsa_header *n, struct ospf_lsa_header *h)
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{
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h->age = ntohs(n->age);
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h->options = n->options;
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h->type = n->type;
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h->id = ntohl(n->id);
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h->rt = ntohl(n->rt);
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h->sn = ntohl(n->sn);
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h->checksum = ntohs(n->checksum);
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h->length = ntohs(n->length);
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};
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void
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htonlsab(void *h, void *n, u8 type, u16 len)
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{
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unsigned int i;
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switch (type)
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{
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case LSA_T_RT:
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{
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struct ospf_lsa_rt *hrt, *nrt;
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struct ospf_lsa_rt_link *hrtl, *nrtl;
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u16 links;
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nrt = n;
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hrt = h;
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links = hrt->links;
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nrt->veb.byte = hrt->veb.byte;
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nrt->padding = 0;
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nrt->links = htons(hrt->links);
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nrtl = (struct ospf_lsa_rt_link *) (nrt + 1);
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hrtl = (struct ospf_lsa_rt_link *) (hrt + 1);
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for (i = 0; i < links; i++)
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{
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(nrtl + i)->id = htonl((hrtl + i)->id);
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(nrtl + i)->data = htonl((hrtl + i)->data);
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(nrtl + i)->type = (hrtl + i)->type;
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(nrtl + i)->notos = (hrtl + i)->notos;
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(nrtl + i)->metric = htons((hrtl + i)->metric);
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}
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break;
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}
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case LSA_T_NET:
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{
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u32 *hid, *nid;
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nid = n;
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hid = h;
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for (i = 0; i < (len / sizeof(u32)); i++)
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{
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*(nid + i) = htonl(*(hid + i));
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}
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break;
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}
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case LSA_T_SUM_NET:
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case LSA_T_SUM_RT:
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{
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struct ospf_lsa_sum *hs, *ns;
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union ospf_lsa_sum_tm *hn, *nn;
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hs = h;
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ns = n;
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ns->netmask = hs->netmask;
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ipa_hton(ns->netmask);
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hn = (union ospf_lsa_sum_tm *) (hs + 1);
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nn = (union ospf_lsa_sum_tm *) (ns + 1);
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for (i = 0; i < ((len - sizeof(struct ospf_lsa_sum)) /
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sizeof(union ospf_lsa_sum_tm)); i++)
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{
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(nn + i)->metric = htonl((hn + i)->metric);
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//(nn + i)->tos = (hn + i)->tos;
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//(nn + i)->metric = htons((hn + i)->metric);
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//(nn + i)->padding = 0;
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}
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break;
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}
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case LSA_T_EXT:
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{
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struct ospf_lsa_ext *he, *ne;
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struct ospf_lsa_ext_tos *ht, *nt;
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he = h;
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ne = n;
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ne->netmask = he->netmask;
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ipa_hton(ne->netmask);
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ht = (struct ospf_lsa_ext_tos *) (he + 1);
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nt = (struct ospf_lsa_ext_tos *) (ne + 1);
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for (i = 0; i < ((len - sizeof(struct ospf_lsa_ext)) /
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sizeof(struct ospf_lsa_ext_tos)); i++)
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{
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(nt + i)->etm.metric = htonl((ht + i)->etm.metric);
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//(nt + i)->tos = (ht + i)->tos;
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//(nt + i)->padding = 0;
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//(nt + i)->metric = htons((ht + i)->metric);
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(nt + i)->fwaddr = (ht + i)->fwaddr;
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ipa_hton((nt + i)->fwaddr);
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(nt + i)->tag = htonl((ht + i)->tag);
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}
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break;
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}
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default:
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bug("(hton): Unknown LSA");
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}
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};
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void
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ntohlsab(void *n, void *h, u8 type, u16 len)
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{
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unsigned int i;
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switch (type)
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{
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case LSA_T_RT:
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{
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struct ospf_lsa_rt *hrt, *nrt;
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struct ospf_lsa_rt_link *hrtl, *nrtl;
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u16 links;
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nrt = n;
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hrt = h;
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hrt->veb.byte = nrt->veb.byte;
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hrt->padding = 0;
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links = hrt->links = ntohs(nrt->links);
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nrtl = (struct ospf_lsa_rt_link *) (nrt + 1);
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hrtl = (struct ospf_lsa_rt_link *) (hrt + 1);
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for (i = 0; i < links; i++)
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{
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(hrtl + i)->id = ntohl((nrtl + i)->id);
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(hrtl + i)->data = ntohl((nrtl + i)->data);
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(hrtl + i)->type = (nrtl + i)->type;
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(hrtl + i)->notos = (nrtl + i)->notos;
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(hrtl + i)->metric = ntohs((nrtl + i)->metric);
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}
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break;
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}
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case LSA_T_NET:
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{
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u32 *hid, *nid;
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hid = h;
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nid = n;
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for (i = 0; i < (len / sizeof(u32)); i++)
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{
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*(hid + i) = ntohl(*(nid + i));
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}
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break;
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}
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case LSA_T_SUM_NET:
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case LSA_T_SUM_RT:
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{
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struct ospf_lsa_sum *hs, *ns;
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union ospf_lsa_sum_tm *hn, *nn;
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hs = h;
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ns = n;
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hs->netmask = ns->netmask;
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ipa_ntoh(hs->netmask);
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hn = (union ospf_lsa_sum_tm *) (hs + 1);
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nn = (union ospf_lsa_sum_tm *) (ns + 1);
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for (i = 0; i < ((len - sizeof(struct ospf_lsa_sum)) /
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sizeof(union ospf_lsa_sum_tm)); i++)
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{
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(hn + i)->metric = ntohl((nn + i)->metric);
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//(hn + i)->tos = (nn + i)->tos;
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//(hn + i)->metric = ntohs((nn + i)->metric);
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//(hn + i)->padding = 0;
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}
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break;
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}
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case LSA_T_EXT:
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{
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struct ospf_lsa_ext *he, *ne;
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struct ospf_lsa_ext_tos *ht, *nt;
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he = h;
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ne = n;
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he->netmask = ne->netmask;
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ipa_ntoh(he->netmask);
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ht = (struct ospf_lsa_ext_tos *) (he + 1);
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nt = (struct ospf_lsa_ext_tos *) (ne + 1);
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for (i = 0; i < ((len - sizeof(struct ospf_lsa_ext)) /
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sizeof(struct ospf_lsa_ext_tos)); i++)
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{
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(ht + i)->etm.metric = ntohl((nt + i)->etm.metric);
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//(ht + i)->etos = (nt + i)->etos;
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//(ht + i)->padding = 0;
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//(ht + i)->metric = ntohs((nt + i)->metric);
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(ht + i)->fwaddr = (nt + i)->fwaddr;
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ipa_ntoh((ht + i)->fwaddr);
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(ht + i)->tag = ntohl((nt + i)->tag);
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}
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break;
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}
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default:
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bug("(ntoh): Unknown LSA");
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}
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};
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#define MODX 4102 /* larges signed value without overflow */
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/* Fletcher Checksum -- Refer to RFC1008. */
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#define MODX 4102
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#define LSA_CHECKSUM_OFFSET 15
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/* FIXME This is VERY uneficient, I have huge endianity problems */
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void
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lsasum_calculate(struct ospf_lsa_header *h, void *body)
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{
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u16 length;
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length = h->length;
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htonlsah(h, h);
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htonlsab(body, body, h->type, length - sizeof(struct ospf_lsa_header));
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(void) lsasum_check(h, body);
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ntohlsah(h, h);
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ntohlsab(body, body, h->type, length - sizeof(struct ospf_lsa_header));
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}
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/*
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* Note, that this function expects that LSA is in big endianity
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* It also returns value in big endian
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*/
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u16
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lsasum_check(struct ospf_lsa_header *h, void *body)
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{
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u8 *sp, *ep, *p, *q, *b;
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int c0 = 0, c1 = 0;
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int x, y;
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u16 length;
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b = body;
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sp = (char *) &h->options;
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length = ntohs(h->length) - 2;
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h->checksum = 0;
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for (ep = sp + length; sp < ep; sp = q)
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{ /* Actually MODX is very large, do we need the for-cyclus? */
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q = sp + MODX;
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if (q > ep)
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q = ep;
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for (p = sp; p < q; p++)
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{
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/*
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* I count with bytes from header and than from body
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* but if there is no body, it's appended to header
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* (probably checksum in update receiving) and I go on
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* after header
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*/
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if ((b == NULL) || (p < (u8 *) (h + 1)))
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{
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c0 += *p;
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}
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else
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{
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c0 += *(b + (p - sp) - sizeof(struct ospf_lsa_header) + 2);
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}
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c1 += c0;
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}
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c0 %= 255;
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c1 %= 255;
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}
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x = ((length - LSA_CHECKSUM_OFFSET) * c0 - c1) % 255;
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if (x <= 0)
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x += 255;
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y = 510 - c0 - x;
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if (y > 255)
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y -= 255;
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((u8 *) & h->checksum)[0] = x;
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((u8 *) & h->checksum)[1] = y;
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return h->checksum;
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}
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int
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lsa_comp(struct ospf_lsa_header *l1, struct ospf_lsa_header *l2)
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/* Return codes from point of view of l1 */
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{
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u32 sn1, sn2;
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sn1 = l1->sn - LSA_INITSEQNO + 1;
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sn2 = l2->sn - LSA_INITSEQNO + 1;
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if (sn1 > sn2)
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return CMP_NEWER;
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if (sn1 < sn2)
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return CMP_OLDER;
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if (l1->checksum != l2->checksum)
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return l1->checksum < l2->checksum ? CMP_OLDER : CMP_NEWER;
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if ((l1->age == LSA_MAXAGE) && (l2->age != LSA_MAXAGE))
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return CMP_NEWER;
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if ((l2->age == LSA_MAXAGE) && (l1->age != LSA_MAXAGE))
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return CMP_OLDER;
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if (ABS(l1->age - l2->age) > LSA_MAXAGEDIFF)
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return l1->age < l2->age ? CMP_NEWER : CMP_OLDER;
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return CMP_SAME;
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}
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/**
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* lsa_install_new - install new LSA into database
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* @lsa: LSA header
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* @body: pointer to LSA body
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* @oa: current ospf_area
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*
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* This function ensures installing new LSA into LSA database. Old instance is
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* replaced. Several actions are taken to detect if new routing table
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* calculation is necessary. This is described in 13.2 of RFC 2328.
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*/
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struct top_hash_entry *
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lsa_install_new(struct ospf_lsa_header *lsa, void *body, struct ospf_area *oa)
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{
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/* LSA can be temporarrily, but body must be mb_allocated. */
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int change = 0;
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unsigned i;
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struct top_hash_entry *en;
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struct proto_ospf *po = oa->po;
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if ((en = ospf_hash_find_header(oa->gr, lsa)) == NULL)
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{
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en = ospf_hash_get_header(oa->gr, lsa);
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change = 1;
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}
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else
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{
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if ((en->lsa.length != lsa->length) || (en->lsa.options != lsa->options)
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|| ((en->lsa.age == LSA_MAXAGE) || (lsa->age == LSA_MAXAGE)))
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change = 1;
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else
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{
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u8 *k = en->lsa_body, *l = body;
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for (i = 0; i < (lsa->length - sizeof(struct ospf_lsa_header)); i++)
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{
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if (*(k + i) != *(l + i))
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{
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change = 1;
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break;
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}
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}
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}
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s_rem_node(SNODE en);
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}
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DBG("Inst lsa: Id: %I, Rt: %I, Type: %u, Age: %u, Sum: %u, Sn: 0x%x\n",
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lsa->id, lsa->rt, lsa->type, lsa->age, lsa->checksum, lsa->sn);
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s_add_tail(&oa->lsal, SNODE en);
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en->inst_t = now;
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if (en->lsa_body != NULL)
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mb_free(en->lsa_body);
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en->lsa_body = body;
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memcpy(&en->lsa, lsa, sizeof(struct ospf_lsa_header));
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en->ini_age = en->lsa.age;
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if (change)
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{
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schedule_rtcalc(po);
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}
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return en;
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}
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