mirror of
https://gitlab.nic.cz/labs/bird.git
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303 lines
6.4 KiB
C
303 lines
6.4 KiB
C
/*
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* BIRD -- OSPF
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*
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* (c) 1999-2000 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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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=hrt->VEB;
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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_summ *hs, *ns;
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struct ospf_lsa_summ_net *hn, *nn;
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hs=h;
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ns=n;
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ns->netmask=htonl(hs->netmask);
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hn=(struct ospf_lsa_summ_net *)(hs+1);
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nn=(struct ospf_lsa_summ_net *)(ns+1);
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for(i=0;i<((len-sizeof(struct ospf_lsa_summ))/
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sizeof(struct ospf_lsa_summ_net));i++)
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{
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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=htonl(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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(nt+i)->etos=(ht+i)->etos;
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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=htonl((ht+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: die("(hton): Unknown LSA\n");
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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=nrt->VEB;
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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_summ *hs, *ns;
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struct ospf_lsa_summ_net *hn, *nn;
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hs=h;
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ns=n;
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hs->netmask=ntohl(ns->netmask);
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hn=(struct ospf_lsa_summ_net *)(hs+1);
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nn=(struct ospf_lsa_summ_net *)(ns+1);
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for(i=0;i<((len-sizeof(struct ospf_lsa_summ))/
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sizeof(struct ospf_lsa_summ_net));i++)
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{
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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=ntohl(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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(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=ntohl((nt+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: die("(ntoh): Unknown LSA\n");
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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,struct proto_ospf *po)
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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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h->checksum = 0;
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b=body;
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length = h->length-2;
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sp = (char *) &h->options;
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htonlsah(h,h);
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htonlsab(b,b,h->type,length+2);
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for (ep = sp + length; sp < ep; sp = q)
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{
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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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if(p<(u8 *)(h+1))
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{
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c0 += *p;
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/*DBG("XXXXXX: %u\t%u\n", p-sp, *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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/*DBG("YYYYYY: %u\t%u\n", p-sp,*(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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h->checksum = x + (y << 8);
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ntohlsah(h,h);
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ntohlsab(b,b,h->type,length+2);
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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 form view of l1 */
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{
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if(l1->sn<l2->sn) return CMP_NEWER;
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if(l1->sn==l2->sn)
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{
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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==MAXAGE) return CMP_NEWER;
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if(l2->age==MAXAGE) return CMP_OLDER;
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if(abs(l1->age-l2->age)>MAXAGEDIFF)
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return l1->age<l2->age ? CMP_NEWER : CMP_OLDER;
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}
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return CMP_SAME;
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}
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