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Now does send acks to self-announcements.

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Considerable work towards supporting 1-byte abbreviations of
addresses. But now there seems to be a memory corruption.
This commit is contained in:
gardners 2011-09-05 16:30:50 +09:30
parent 74efa738be
commit b0680bd6e0
2 changed files with 64 additions and 12 deletions
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7
mphlr.h
View File

@ -400,7 +400,7 @@ typedef struct overlay_frame {
struct overlay_buffer *payload;
int rfs; /* remainder of frame size */
long long enqueued_at;
} overlay_frame;
@ -760,7 +760,11 @@ typedef struct overlay_neighbour {
This is so that the sender knows which interface to use to reach us.
*/
unsigned char scores[OVERLAY_MAX_INTERFACES];
/* One-byte index entries for address abbreviation */
unsigned char one_byte_index_address_prefixes[256][OVERLAY_SENDER_PREFIX_LENGTH];
} overlay_neighbour;
extern overlay_neighbour *overlay_neighbours;
long long overlay_gettime_ms();
int overlay_route_init(int mb_ram);
@ -782,3 +786,4 @@ int packetEncipher(unsigned char *packet,int maxlen,int *len,int cryptoflags);
int overlayServerMode();
int overlay_payload_enqueue(int q,overlay_frame *p);
long long overlay_time_in_ms();
int overlay_abbreviate_lookup_sender_id();

69
overlay_abbreviations.c
View File

@ -88,6 +88,16 @@
full address. Given that we already have need for the clarification process, let's
go that way, and change the policy later if appropriate.
Having had said this, on mono-directional links there is a problem with using the
various abbreviation schemes that require state. And this is that the receiver has
no way to issue a please-explain. In these situations, we need to fall-back to at
most using the abbreviations only most of the time, and still sending the full-address
some of the time, so that even without a feedback look to ask for explanations the
receiver should synchronise with us fairly well.
Also, we haven't implemented index-based lookup on the receiver side, so we need to fix
that or disable it on the sender side.
*/
typedef struct overlay_address_table {
@ -189,14 +199,31 @@ int overlay_abbreviate_cache_address(unsigned char *sid)
return 0;
}
int overlay_abbreviate_try_byindex(unsigned char *in,unsigned char *out,int *ofs,int index)
int overlay_abbreviate_try_byindex(unsigned char *in,unsigned char *out,int *ofs,
int index)
{
if(!memcmp(in,abbrs->sids[index],SID_SIZE))
{
/* We can encode this address with one byte */
out[(*ofs)++]=0x01;
out[(*ofs)++]=index;
return 0;
/* We can encode this address with one byte */
/* Don't always abbreviate as the receiver may not have the means to send us
please-explains, e.g., due to mono-directional links. Thus we want to resend
the whole address sometimes. */
if (random()&7) {
/* Do use abbreviation */
out[(*ofs)++]=0x01;
out[(*ofs)++]=index;
return 0;
} else {
/* Don't use the abbreviation this time, but rather repeat it again for the
receiving side to cache.
XXX - Should we use a prefix here instead of full length?
*/
out[(*ofs)++]=0x08;
bcopy(in,&out[(*ofs)],SID_SIZE);
(*ofs)+=SID_SIZE;
out[(*ofs)++]=index;
return 0;
}
}
else
/* Cannot find index in our node list. */
@ -242,7 +269,8 @@ int overlay_abbreviate_address(unsigned char *in,unsigned char *out,int *ofs)
XXX If we do, we need a way to indicate a reference to an old epoch */
for(i=0;i<2;i++)
if (abbrs->byfirstbyte[in[0]][i])
{ if (!overlay_abbreviate_try_byindex(in,out,ofs,i)) return 0; }
{ if (!overlay_abbreviate_try_byindex(in,out,ofs,abbrs->byfirstbyte[in[0]][i]))
return 0; }
else break;
if (i<2&&abbrs->next_free) {
// There is a spare slot to abbreviate this address by storing it in an index if we
@ -296,9 +324,13 @@ int overlay_abbreviate_expand_address(int interface,unsigned char *in,int *inofs
WHY("Reserved address abbreviation code");
return OA_UNSUPPORTED;
case OA_CODE_INDEX: /* single byte index look up */
WHY("Unimplemented address abbreviation code (single byte index lookup)");
overlay_interface_repeat_abbreviation_policy[interface]=1;
return OA_UNSUPPORTED;
/* Lookup sender's neighbour ID */
if (overlay_abbreviate_current_sender_id==-1) if (overlay_abbreviate_lookup_sender_id()) return WHY("could not lookup neighbour ID of packet sender");
r=overlay_abbreviate_cache_lookup(overlay_neighbours[overlay_abbreviate_current_sender_id].one_byte_index_address_prefixes[in[*inofs]],
out,ofs,OVERLAY_SENDER_PREFIX_LENGTH,0);
(*inofs)++;
overlay_abbreviate_set_most_recent_address(&out[*ofs]);
return r;
case OA_CODE_PREVIOUS: /* Same as last address */
(*inofs)++;
bcopy(&overlay_abbreviate_previous_address.b[0],&out[*ofs],SID_SIZE);
@ -343,18 +375,33 @@ int overlay_abbreviate_expand_address(int interface,unsigned char *in,int *inofs
}
}
int overlay_abbreviate_lookup_sender_id()
{
overlay_neighbour *neh=overlay_route_get_neighbour_structure(overlay_abbreviate_current_sender.b,1 /* create if needed */);
if (!neh) { overlay_abbreviate_current_sender_id=-1; return WHY("Could not find sender in neighbour list"); }
/* Okay, so the following is a little tortuous in asking our parent who we are instead of just knowing,
but it will do for now */
overlay_abbreviate_current_sender_id=neh->node->neighbour_id;
return 0;
}
int overlay_abbreviate_remember_index(int index_byte_count,unsigned char *sid_to_remember,unsigned char *index_bytes)
{
int zero=0;
char sid[SID_SIZE*2+1];
int index=index_bytes[0];
if (index_byte_count>1) index=(index<<8)|index_bytes[1];
fprintf(stderr,"index=%d\n",index);
/* Lookup sender's neighbour ID */
if (overlay_abbreviate_current_sender_id==-1) overlay_abbreviate_lookup_sender_id();
fprintf(stderr,"index=%d\n",index);
sid[0]=0; extractSid(sid_to_remember,&zero,sid);
fprintf(stderr,"We need to remember that the sender #%d has assigned index #%d to the following:\n [%s]\n",
overlay_abbreviate_current_sender_id,index,sid);
return WHY("Not implemented");
bcopy(sid_to_remember,overlay_neighbours[overlay_abbreviate_current_sender_id].one_byte_index_address_prefixes[index],OVERLAY_SENDER_PREFIX_LENGTH);
return 0;
}
int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *ofs,