int
nsm_adj_ok (struct ospf_neighbor *nbr)
{
struct ospf_interface *oi;
int next_state;
int flag = 0;
oi = nbr->oi;
next_state = nbr->state;
/* These netowork types must be adjacency. */
if (oi->type == OSPF_IFTYPE_POINTOPOINT
|| oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
|| oi->type == OSPF_IFTYPE_VIRTUALLINK)
flag = 1;
/* Router itself is the DRouter or the BDRouter. */
if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
|| IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
flag = 1;
if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
|| IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
flag = 1;
if (nbr->state == NSM_TwoWay && flag == 1)
next_state = NSM_ExStart;
else if (nbr->state >= NSM_ExStart && flag == 0)
next_state = NSM_TwoWay;
return next_state;
}
int
ospf_dr_election (struct ospf_interface *oi)
{
struct in_addr old_dr, old_bdr;
int old_state, new_state;
struct list *el_list;
struct ospf_neighbor *dr, *bdr;
/* backup current values. */
old_dr = DR (oi);
old_bdr = BDR (oi);
old_state = oi->state;
el_list = list_new ();
/* List eligible routers. */
ospf_dr_eligible_routers (oi->nbrs, el_list);
/* First election of DR and BDR. */
bdr = ospf_elect_bdr (oi, el_list);
dr = ospf_elect_dr (oi, el_list);
new_state = ospf_ism_state (oi);
zlog_info ("DR-Election[1st]: Backup %s", inet_ntoa (BDR (oi)));
zlog_info ("DR-Election[1st]: DR %s", inet_ntoa (DR (oi)));
if (new_state != old_state &&
!(new_state == ISM_DROther && old_state < ISM_DROther))
{
ospf_elect_bdr (oi, el_list);
ospf_elect_dr (oi, el_list);
new_state = ospf_ism_state (oi);
zlog_info ("DR-Election[2nd]: Backup %s", inet_ntoa (BDR (oi)));
zlog_info ("DR-Election[2nd]: DR %s", inet_ntoa (DR (oi)));
}
list_delete (el_list);
/* if DR or BDR changes, cause AdjOK? neighbor event. */
if (!IPV4_ADDR_SAME (&old_dr, &DR (oi)) ||
!IPV4_ADDR_SAME (&old_bdr, &BDR (oi)))
ospf_dr_change (oi->ospf, oi->nbrs);
if (oi->type == OSPF_IFTYPE_BROADCAST || oi->type == OSPF_IFTYPE_POINTOPOINT)
{
/* Multicast group change. */
if ((old_state != ISM_DR && old_state != ISM_Backup) &&
(new_state == ISM_DR || new_state == ISM_Backup))
ospf_if_add_alldrouters (oi->ospf, oi->address, oi->ifp->ifindex);
else if ((old_state == ISM_DR || old_state == ISM_Backup) &&
(new_state != ISM_DR && new_state != ISM_Backup))
ospf_if_drop_alldrouters (oi->ospf, oi->address, oi->ifp->ifindex);
}
return new_state;
}
static int
ospf_dr_election (struct ospf_interface *oi)
{
struct in_addr old_dr, old_bdr;
int old_state, new_state;
struct list *el_list;
struct ospf_neighbor *dr, *bdr;
/* backup current values. */
old_dr = DR (oi);
old_bdr = BDR (oi);
old_state = oi->state;
el_list = list_new ();
/* List eligible routers. */
ospf_dr_eligible_routers (oi->nbrs, el_list);
/* First election of DR and BDR. */
bdr = ospf_elect_bdr (oi, el_list);
dr = ospf_elect_dr (oi, el_list);
new_state = ospf_ism_state (oi);
zlog_info ("DR-Election[1st]: Backup %s", inet_ntoa (BDR (oi)));
zlog_info ("DR-Election[1st]: DR %s", inet_ntoa (DR (oi)));
if (new_state != old_state &&
!(new_state == ISM_DROther && old_state < ISM_DROther))
{
ospf_elect_bdr (oi, el_list);
ospf_elect_dr (oi, el_list);
new_state = ospf_ism_state (oi);
zlog_info ("DR-Election[2nd]: Backup %s", inet_ntoa (BDR (oi)));
zlog_info ("DR-Election[2nd]: DR %s", inet_ntoa (DR (oi)));
}
list_delete (el_list);
/* if DR or BDR changes, cause AdjOK? neighbor event. */
if (!IPV4_ADDR_SAME (&old_dr, &DR (oi)) ||
!IPV4_ADDR_SAME (&old_bdr, &BDR (oi)))
ospf_dr_change (oi->ospf, oi->nbrs);
return new_state;
}
int
nsm_twoway_received (struct ospf_neighbor *nbr)
{
struct ospf_interface *oi;
int next_state = NSM_TwoWay;
oi = nbr->oi;
/* These netowork types must be adjacency. */
if (oi->type == OSPF_IFTYPE_POINTOPOINT ||
oi->type == OSPF_IFTYPE_POINTOMULTIPOINT ||
oi->type == OSPF_IFTYPE_VIRTUALLINK)
next_state = NSM_ExStart;
/* Router itself is the DRouter or the BDRouter. */
if (IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi)) ||
IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi)))
next_state = NSM_ExStart;
/* Neighboring Router is the DRouter or the BDRouter. */
if (IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->d_router) ||
IPV4_ADDR_SAME (&nbr->address.u.prefix4, &nbr->bd_router))
next_state = NSM_ExStart;
return next_state;
}
struct ospf_neighbor *
ospf_elect_bdr (struct ospf_interface *oi, struct list *el_list)
{
struct list *bdr_list, *no_dr_list;
struct listnode *node;
struct ospf_neighbor *nbr, *bdr = NULL;
bdr_list = list_new ();
no_dr_list = list_new ();
/* Add neighbors to the list. */
for (node = listhead (el_list); node; nextnode (node))
{
nbr = getdata (node);
/* neighbor declared to be DR. */
if (NBR_IS_DR (nbr))
continue;
/* neighbor declared to be BDR. */
if (NBR_IS_BDR (nbr))
listnode_add (bdr_list, nbr);
listnode_add (no_dr_list, nbr);
}
/* Elect Backup Designated Router. */
if (listcount (bdr_list) > 0)
bdr = ospf_dr_election_sub (bdr_list);
else
bdr = ospf_dr_election_sub (no_dr_list);
/* Set BDR to interface. */
if (bdr)
{
BDR (oi) = bdr->address.u.prefix4;
bdr->bd_router = bdr->address.u.prefix4;
}
else
BDR (oi).s_addr = 0;
list_delete (bdr_list);
list_delete (no_dr_list);
return bdr;
}
static int ospf_ism_state(struct ospf_interface *oi)
{
if (IPV4_ADDR_SAME(&DR(oi), &oi->address->u.prefix4))
return ISM_DR;
else if (IPV4_ADDR_SAME(&BDR(oi), &oi->address->u.prefix4))
return ISM_Backup;
else
return ISM_DROther;
}
/* 10.4 of RFC2328, indicate whether an adjacency is appropriate with
* the given neighbour
*/
static int
nsm_should_adj (struct ospf_neighbor *nbr)
{
struct ospf_interface *oi = nbr->oi;
/* These network types must always form adjacencies. */
if (oi->type == OSPF_IFTYPE_POINTOPOINT
|| oi->type == OSPF_IFTYPE_POINTOMULTIPOINT
|| oi->type == OSPF_IFTYPE_VIRTUALLINK
/* Router itself is the DRouter or the BDRouter. */
|| IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))
|| IPV4_ADDR_SAME (&oi->address->u.prefix4, &BDR (oi))
/* Neighboring Router is the DRouter or the BDRouter. */
|| IPV4_ADDR_SAME (&nbr->address.u.prefix4, &DR (oi))
|| IPV4_ADDR_SAME (&nbr->address.u.prefix4, &BDR (oi)))
return 1;
return 0;
}
void ospf_nbr_state_message(struct ospf_neighbor *nbr, char *buf, size_t size)
{
int state;
struct ospf_interface *oi = nbr->oi;
if (IPV4_ADDR_SAME(&DR(oi), &nbr->address.u.prefix4))
state = ISM_DR;
else if (IPV4_ADDR_SAME(&BDR(oi), &nbr->address.u.prefix4))
state = ISM_Backup;
else
state = ISM_DROther;
snprintf(buf, size, "%s/%s",
lookup_msg(ospf_nsm_state_msg, nbr->state, NULL),
lookup_msg(ospf_ism_state_msg, state, NULL));
}
struct ospf_neighbor *
ospf_elect_dr (struct ospf_interface *oi, struct list *el_list)
{
struct list *dr_list;
struct listnode *node;
struct ospf_neighbor *nbr, *dr = NULL, *bdr = NULL;
dr_list = list_new ();
/* Add neighbors to the list. */
for (node = listhead (el_list); node; nextnode (node))
{
nbr = getdata (node);
/* neighbor declared to be DR. */
if (NBR_IS_DR (nbr))
listnode_add (dr_list, nbr);
/* Preserve neighbor BDR. */
if (IPV4_ADDR_SAME (&BDR (oi), &nbr->address.u.prefix4))
bdr = nbr;
}
/* Elect Designated Router. */
if (listcount (dr_list) > 0)
dr = ospf_dr_election_sub (dr_list);
else
dr = bdr;
/* Set DR to interface. */
if (dr)
{
DR (oi) = dr->address.u.prefix4;
dr->d_router = dr->address.u.prefix4;
}
else
DR (oi).s_addr = 0;
list_delete (dr_list);
return dr;
}
static int DecodeACSign(WinZipJPEGDecompressor *self,int comp,unsigned int k,int absvalue,
const WinZipJPEGBlock *current,const WinZipJPEGBlock *north,const WinZipJPEGBlock *west,
const WinZipJPEGQuantizationTable *quantization)
{
// Decode sign. (5.6.6.4)
// Calculate sign context, or decode with fixed probability. (5.6.6.4.1)
int predictedsign;
if(IsFirstRowOrColumn(k))
{
int bdr=BDR(k,current,north,west,quantization);
if(bdr==0) return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,&self->fixedcontext);
predictedsign=(bdr<0);
}
else if(k==4)
{
int sign1=Sign(north->c[k]);
int sign2=Sign(west->c[k]);
if(sign1+sign2==0) return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,&self->fixedcontext);
predictedsign=(sign1+sign2<0);
}
else if(IsSecondRow(k))
{
if(north->c[k]==0) return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,&self->fixedcontext);
predictedsign=(north->c[k]<0);
}
else if(IsSecondColumn(k))
{
if(west->c[k]==0) return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,&self->fixedcontext);
predictedsign=(west->c[k]<0);
}
else
{
return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,&self->fixedcontext);
}
static const int n_for_k[64]={
0,
0, 1,
2, 3, 4,
5, 6, 7, 8,
9,10, 0,11,12,
13,14, 0, 0,15,16,
17,18, 0, 0, 0,19,20,
21,22, 0, 0, 0, 0,23,24,
25, 0, 0, 0, 0, 0,26,
0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0,
0, 0,
0,
};
int n=n_for_k[k];
int signcontext1=Min(Category(absvalue)/2,2);
return NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,
&self->acsignbins[comp][n][signcontext1][predictedsign]);
}
static int DecodeACComponent(WinZipJPEGDecompressor *self,int comp,unsigned int k,bool canbezero,
const WinZipJPEGBlock *current,const WinZipJPEGBlock *north,const WinZipJPEGBlock *west,
const WinZipJPEGQuantizationTable *quantization)
{
if(!north) north=&ZeroBlock;
if(!west) west=&ZeroBlock;
int val1;
if(IsFirstRowOrColumn(k)) val1=Abs(BDR(k,current,north,west,quantization));
else val1=Average(k,north,west,quantization);
int val2=Sum(k,current);
if(canbezero)
{
// Decode zero/non-zero bit. (5.6.6.1)
int zerocontext1=Min(Category(val1),2);
int zerocontext2=Min(Category(val2),5);
int nonzero=NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,
&self->zerobins[comp][k-1][zerocontext1][zerocontext2]);
// If this component is zero, there is no need to decode further parameters.
if(!nonzero) return 0;
}
// This component is not zero. Proceed with decoding absolute value.
int absvalue;
// Decode pivot (abs>=2). (5.6.6.2)
int pivotcontext1=Min(Category(val1),4);
int pivotcontext2=Min(Category(val2),6);
int pivot=NextBitFromWinZipJPEGArithmeticDecoder(&self->decoder,
&self->pivotbins[comp][k-1][pivotcontext1][pivotcontext2]);
if(!pivot)
{
// The absolute of this component is not >=2. It must therefore be 1,
// and there is no need to decode the value.
absvalue=1;
}
else
{
// The absolute of this component is >=2. Proceed with decoding
// the absolute value. (5.6.6.3)
int val3,n;
if(IsFirstRow(k)) { val3=Column(k)-1; n=0; }
else if(IsFirstColumn(k)) { val3=Row(k)-1; n=1; }
else { val3=Category(k-4); n=2; }
int magnitudecontext1=Min(Category(val1),8);
int magnitudecontext2=Min(Category(val2),8);
int remaindercontext=val3;
// Decode absolute value.
absvalue=DecodeBinarization(&self->decoder,
self->acmagnitudebins[comp][n][magnitudecontext1][magnitudecontext2],
self->acremainderbins[comp][n][remaindercontext],
14,9)+2;
}
if(DecodeACSign(self,comp,k,absvalue,current,north,west,quantization)) return -absvalue;
else return absvalue;
}
static void CompressACSign(JPEGCompressor *self,int comp,unsigned int k,int absvalue,
const JPEGBlock *current,const JPEGBlock *north,const JPEGBlock *west,
const JPEGQuantizationTable *quantization)
{
int sign=current->c[k]<0;
// Calculate sign context, or compress with fixed probability.
int predictedsign;
if(IsFirstRowOrColumn(k))
{
int bdr=BDR(k,current,north,west,quantization);
if(bdr==0)
{
WriteBit(&self->encoder,sign,0x800);
return;
}
predictedsign=(bdr<0);
}
else if(k==4)
{
int sign1=Sign(north->c[k]);
int sign2=Sign(west->c[k]);
if(sign1+sign2==0)
{
WriteBit(&self->encoder,sign,0x800);
return;
}
predictedsign=(sign1+sign2<0);
}
else if(IsSecondRow(k))
{
if(north->c[k]==0)
{
WriteBit(&self->encoder,sign,0x800);
return;
}
predictedsign=(north->c[k]<0);
}
else if(IsSecondColumn(k))
{
if(west->c[k]==0)
{
WriteBit(&self->encoder,sign,0x800);
return;
}
predictedsign=(west->c[k]<0);
}
else
{
WriteBit(&self->encoder,sign,0x800);
return;
}
static const int n_for_k[64]={
0,
0, 1,
2, 3, 4,
5, 6, 7, 8,
9,10, 0,11,12,
13,14, 0, 0,15,16,
17,18, 0, 0, 0,19,20,
21,22, 0, 0, 0, 0,23,24,
25, 0, 0, 0, 0, 0,26,
0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0,
0, 0,
0,
};
int n=n_for_k[k];
int signcontext1=Min(Category(absvalue)/2,2);
WriteDynamicBit(&self->encoder,sign,
&self->acsignbins[comp][n][signcontext1][predictedsign],
self->acsignshift);
}
static void CompressACComponent(JPEGCompressor *self,int comp,unsigned int k,bool canbezero,
const JPEGBlock *current,const JPEGBlock *north,const JPEGBlock *west,
const JPEGQuantizationTable *quantization)
{
int value=current->c[k];
if(!north) north=&ZeroBlock;
if(!west) west=&ZeroBlock;
int val1;
if(IsFirstRowOrColumn(k)) val1=Abs(BDR(k,current,north,west,quantization));
else val1=Average(k,north,west,quantization);
int val2=Sum(k,current);
if(canbezero)
{
// Compress zero/non-zero bit.
int zerocontext1=Min(Category(val1),2);
int zerocontext2=Min(Category(val2),5);
WriteDynamicBit(&self->encoder,value!=0,
&self->zerobins[comp][k-1][zerocontext1][zerocontext2],
self->zeroshift);
// If this component is zero, there is no need to compress further parameters.
if(value==0) return;
}
// This component is not zero. Proceed with compressing absolute value.
int absvalue=Abs(value);
// Compress pivot (abs>=2).
int pivotcontext1=Min(Category(val1),4);
int pivotcontext2=Min(Category(val2),6);
WriteDynamicBit(&self->encoder,absvalue>1,
&self->pivotbins[comp][k-1][pivotcontext1][pivotcontext2],
self->pivotshift);
if(absvalue>1)
{
// The absolute of this component is >=2. Proceed with compressing
// the absolute value.
int val3,n;
if(IsFirstRow(k)) { val3=Column(k)-1; n=0; }
else if(IsFirstColumn(k)) { val3=Row(k)-1; n=1; }
else { val3=Category(k-4); n=2; }
int magnitudecontext1=Min(Category(val1),8);
int magnitudecontext2=Min(Category(val2),8);
int remaindercontext=val3;
// Compress absolute value.
WriteUniversalCode(&self->encoder,absvalue-2,
self->acmagnitudebins[comp][n][magnitudecontext1][magnitudecontext2],
self->acmagnitudeshift,
self->acremainderbins[comp][n][remaindercontext],
self->acremaindershift);
}
CompressACSign(self,comp,k,absvalue,current,north,west,quantization);
}