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Fixed bugs with overlay frame parsing.

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This commit is contained in:
gardners 2011-08-15 13:10:37 +02:00
parent cf778e1efd
commit 02bf80246e
4 changed files with 37 additions and 17 deletions
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2
mphlr.h
View File

@ -648,7 +648,7 @@ extern int overlay_interface_count;
#define OVERLAY_ADDRESS_CACHE_SIZE 1024
int overlay_abbreviate_address(unsigned char *in,char *out,int *ofs);
int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char *out,int *ofs);
int overlay_abbreviate_expand_address(int interface,unsigned char *in,int *inofs,unsigned char *out,int *ofs);
int overlay_address_cache_address(unsigned char *sid);
int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *ofs,
int prefix_bytes,int index_bytes);

4
overlay.c
View File

@ -145,6 +145,10 @@ int overlay_frame_process(int interface,overlay_frame *f)
/* Okay, nexthop is valid, so let's see if it is us */
int forMe=0,i;
fprintf(stderr,"Nexthop for this frame is: ");
for(i=0;i<SID_SIZE;i++) fprintf(stderr,"%02x",f->nexthop[i]);
fprintf(stderr,"\n");
for(i=0;i<SID_SIZE;i++) if (f->nexthop[i]!=0xff) break;
if (i==SID_SIZE) forMe=1;
for(i=0;i<SID_SIZE;i++) if (f->nexthop[i]!=hlr[4+i]) break;

42
overlay_abbreviations.c
View File

@ -259,10 +259,11 @@ int overlay_abbreviate_address(unsigned char *in,char *out,int *ofs)
}
int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char *out,int *ofs)
int overlay_abbreviate_expand_address(int interface,unsigned char *in,int *inofs,unsigned char *out,int *ofs)
{
int bytes=0;
switch(in[0])
fprintf(stderr,"Address first byte/abbreviation code=%02x (input offset=%d)\n",in[*inofs],*inofs);
switch(in[*inofs])
{
case OA_CODE_00: case OA_CODE_02: case OA_CODE_04: case OA_CODE_0C:
/* Unsupported codes, so tell the sender
@ -270,7 +271,8 @@ int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char
(*inofs)++;
return OA_UNSUPPORTED;
case OA_CODE_INDEX: /* single byte index look up */
exit(WHY("Unimplemented address abbreviation code"));
WHY("Unimplemented address abbreviation code");
overlay_interface_repeat_abbreviation_policy[interface]=1;
break;
case OA_CODE_PREVIOUS: /* Same as last address */
(*inofs)++;
@ -279,29 +281,32 @@ int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char
return OA_RESOLVED;
break;
case OA_CODE_PREFIX3: case OA_CODE_PREFIX3_INDEX1: /* 3-byte prefix */
if (in[0]==0x09) bytes=1;
if (in[*inofs]==0x09) bytes=1;
(*inofs)+=3+bytes;
return overlay_abbreviate_cache_lookup(in,out,ofs,3,bytes);
return overlay_abbreviate_cache_lookup(&in[1],out,ofs,3,bytes);
case OA_CODE_PREFIX7: case OA_CODE_PREFIX7_INDEX1: /* 7-byte prefix */
if (in[0]==OA_CODE_PREFIX7_INDEX1) bytes=1;
if (in[*inofs]==OA_CODE_PREFIX7_INDEX1) bytes=1;
(*inofs)+=7+bytes;
return overlay_abbreviate_cache_lookup(in,out,ofs,7,bytes);
WHY("Resolving address from 7-byte prefix");
return overlay_abbreviate_cache_lookup(&in[(*inofs)+1],out,ofs,7,bytes);
case OA_CODE_PREFIX11: case OA_CODE_PREFIX11_INDEX1: case OA_CODE_PREFIX11_INDEX2: /* 11-byte prefix */
if (in[0]==OA_CODE_PREFIX11_INDEX1) bytes=1;
if (in[0]==OA_CODE_PREFIX11_INDEX2) bytes=2;
if (in[*inofs]==OA_CODE_PREFIX11_INDEX1) bytes=1;
if (in[*inofs]==OA_CODE_PREFIX11_INDEX2) bytes=2;
(*inofs)+=11+bytes;
return overlay_abbreviate_cache_lookup(in,out,ofs,11,bytes);
return overlay_abbreviate_cache_lookup(&in[(*inofs)+1],out,ofs,11,bytes);
case OA_CODE_BROADCAST: /* broadcast */
memset(&out[*ofs],0xff,SID_SIZE);
(*inofs)++;
WHY("Resolved address (broadcast)");
return OA_RESOLVED;
case OA_CODE_FULL_INDEX1: case OA_CODE_FULL_INDEX2:
default: /* Full address, optionally followed by index for us to remember */
if (in[0]==OA_CODE_FULL_INDEX1) bytes=1;
if (in[0]==OA_CODE_FULL_INDEX2) bytes=2;
bcopy(in,&out[*ofs],SID_SIZE);
if (bytes) overlay_abbreviate_remember_index(bytes,in,&in[SID_SIZE]);
if (in[*inofs]==OA_CODE_FULL_INDEX1) bytes=1;
if (in[*inofs]==OA_CODE_FULL_INDEX2) bytes=2;
bcopy(&in,&out[*ofs],SID_SIZE);
if (bytes) overlay_abbreviate_remember_index(bytes,in,&in[(*inofs)+SID_SIZE]);
(*inofs)+=SID_SIZE+bytes;
WHY("Resolved address (full address provided)");
return OA_RESOLVED;
}
}
@ -327,6 +332,11 @@ int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *of
/* Work out the index in the cache where this address would live */
int index=((in[0]<<16)|(in[0]<<8)|in[2])>>cache->shift;
int i;
fprintf(stderr,"Looking in cache slot #%d for: ",index);
for(i=0;i<prefix_bytes;i++) fprintf(stderr,"%02x",cache->sids[index].b[i]);
fprintf(stderr,"*\n");
/* So is it there? */
if (bcmp(in,&cache->sids[index].b[0],prefix_bytes))
{
@ -338,6 +348,10 @@ int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *of
colliding prefixes and ask the sender to resolve them for us */
/* It is here, so let's return it */
fprintf(stderr,"I think I looked up the following: ");
for(i=0;i<SID_SIZE;i++) fprintf(stderr,"%02x",cache->sids[index].b[i]);
fprintf(stderr,"\n");
bcopy(&cache->sids[index].b[0],&out[(*ofs)],SID_SIZE);
(*ofs)+=SID_SIZE;
if (index_bytes) {

6
overlay_packetformats.c
View File

@ -72,7 +72,8 @@ int packetOkOverlay(int interface,unsigned char *packet,int len,unsigned char *t
int ofs;
overlay_frame f;
for(ofs=0;ofs<len;)
/* Skip magic bytes and version */
for(ofs=4;ofs<len;)
{
/* Clear out the data structure ready for next frame */
f.nexthop_address_status=OA_UNINITIALISED;
@ -117,6 +118,7 @@ int packetOkOverlay(int interface,unsigned char *packet,int len,unsigned char *t
/* Get length of remainder of frame */
f.rfs=packet[ofs];
while (packet[ofs]==0xff&&(ofs<len)&&(f.rfs<16384)) f.rfs+=packet[++ofs];
ofs++;
if (!f.rfs) {
/* Zero length -- assume we fell off the end of the packet */
@ -126,7 +128,7 @@ int packetOkOverlay(int interface,unsigned char *packet,int len,unsigned char *t
/* Now extract the next hop address */
int alen=0;
int offset=ofs;
f.nexthop_address_status=overlay_abbreviate_expand_address(packet,&offset,f.nexthop,&alen);
f.nexthop_address_status=overlay_abbreviate_expand_address(interface,packet,&offset,f.nexthop,&alen);
/* Now just make the rest of the frame available via the received frame structure, as the
frame may not be for us, so there is no point wasting time and energy if we don't have