// process an incoming handshake
link_t link_receive_handshake(link_t link, lob_t inner)
{
uint32_t out, at, err;
uint8_t csid = 0;
lob_t outer = lob_linked(inner);
if(!link || !inner || !outer) return LOG("bad args");
// inner/link must be validated by caller already, we just load if missing
if(!link->key)
{
util_unhex(lob_get(inner, "csid"), 2, &csid);
if(!link_load(link, csid, inner))
{
lob_free(inner);
return LOG("load key failed for %s %u %s",hashname_short(link->id),csid,util_hex(inner->body,inner->body_len,NULL));
}
}
if((err = e3x_exchange_verify(link->x,outer)))
{
lob_free(inner);
return LOG("handshake verification fail: %d",err);
}
out = e3x_exchange_out(link->x,0);
at = lob_get_uint(inner,"at");
link_t ready = link_up(link);
// if bad at, always send current handshake
if(e3x_exchange_in(link->x, at) < out)
{
LOG("old handshake: %s (%d,%d,%d)",lob_json(inner),at,out);
link_sync(link);
lob_free(inner);
return link;
}
// try to sync ephemeral key
if(!e3x_exchange_sync(link->x,outer))
{
lob_free(inner);
return LOG("sync failed");
}
// we may need to re-sync
if(out != e3x_exchange_out(link->x,0)) link_sync(link);
// notify of ready state change
if(!ready && link_up(link))
{
LOG("link ready");
mesh_link(link->mesh, link);
}
link->handshake = lob_free(link->handshake);
link->handshake = inner;
return link;
}
// process an incoming handshake
link_t link_receive_handshake(link_t link, lob_t inner, pipe_t pipe)
{
link_t ready;
uint32_t out, err;
seen_t seen;
uint8_t csid = 0;
char *hexid;
lob_t attached, outer = lob_linked(inner);
if(!link || !inner || !outer) return LOG("bad args");
hexid = lob_get(inner, "csid");
if(!lob_get(link->mesh->keys, hexid)) return LOG("unsupported csid %s",hexid);
util_unhex(hexid, 2, &csid);
attached = lob_parse(inner->body, inner->body_len);
if(!link->key && link_key(link->mesh, attached, csid) != link) return LOG("invalid/mismatch link handshake");
if((err = e3x_exchange_verify(link->x,outer))) return LOG("handshake verification fail: %d",err);
out = e3x_exchange_out(link->x,0);
ready = link_up(link);
// if bad at, always send current handshake
if(e3x_exchange_in(link->x, lob_get_uint(inner,"at")) < out)
{
LOG("old/bad at: %s (%d,%d,%d)",lob_json(inner),lob_get_int(inner,"at"),e3x_exchange_in(link->x,0),e3x_exchange_out(link->x,0));
// just reset pipe seen and call link_sync to resend handshake
for(seen = link->pipes;pipe && seen;seen = seen->next) if(seen->pipe == pipe) seen->at = 0;
lob_free(link_sync(link));
return NULL;
}
// trust/add this pipe
if(pipe) link_pipe(link,pipe);
// try to sync ephemeral key
if(!e3x_exchange_sync(link->x,outer)) return LOG("sync failed");
// we may need to re-sync
if(out != e3x_exchange_out(link->x,0)) lob_free(link_sync(link));
// notify of ready state change
if(!ready && link_up(link))
{
LOG("link ready");
mesh_link(link->mesh, link);
}
return link;
}
net_serial_t net_serial_new(mesh_t mesh, lob_t options)
{
net_serial_t net;
unsigned int pipes;
if(!(net = malloc(sizeof (struct net_serial_struct)))) return LOG("OOM");
memset(net,0,sizeof (struct net_serial_struct));
pipes = lob_get_uint(options,"pipes");
if(!pipes) pipes = 3; // hashtable for active pipes
net->pipes = xht_new(pipes);
// connect us to this mesh
net->mesh = mesh;
xht_set(mesh->index, "net_serial", net);
return net;
}
// get paths from host and query
lob_t util_uri_paths(lob_t uri)
{
uint32_t i;
uint16_t port;
uint8_t *buf;
size_t len;
char *key, *value;
lob_t paths, query = lob_linked(uri);
if(!query) return NULL;
paths = NULL;
// gen paths from host/port
if((port = lob_get_uint(uri,"port")))
{
key = lob_get(uri,"host");
paths = lob_chain(paths);
lob_set(paths,"type","upd4");
lob_set(paths,"ip",key);
lob_set_uint(paths,"port",port);
paths = lob_chain(paths);
lob_set(paths,"type","tcp4");
lob_set(paths,"ip",key);
lob_set_uint(paths,"port",port);
}
// loop through all keyval pairs to find paths
buf = NULL;
for(i=0;(key = lob_get_index(query,i));i+=2)
{
value = lob_get_index(query,i+1);
if(util_cmp(key,"paths") != 0 || !value) continue;
len = base32_decode_floor(strlen(value));
buf = util_reallocf(buf,len);
if(!buf) continue;
if(base32_decode(value,strlen(value),buf,len) < len) continue;
paths = lob_link(lob_parse(buf,len), paths);
}
free(buf);
return paths;
}
// validate the next incoming channel id from the packet, or return the next avail outgoing channel id
uint32_t e3x_exchange_cid(e3x_exchange_t x, lob_t incoming)
{
uint32_t cid;
if(!x) return 0;
// in outgoing mode, just return next valid one
if(!incoming)
{
cid = x->cid;
x->cid += 2;
return cid;
}
// incoming mode, verify it
if(!(cid = lob_get_uint(incoming,"c"))) return 0;
if(cid <= x->last) return 0; // can't re-use old ones
// make sure it's even/odd properly
if((cid % 2) == (x->cid % 2)) return 0;
x->last = cid; // track the highest
return cid;
}
// process any unencrypted handshake packet
link_t mesh_receive_handshake(mesh_t mesh, lob_t handshake, pipe_t pipe)
{
uint32_t now;
hashname_t from;
link_t link;
if(!mesh || !handshake) return LOG("bad args");
if(!lob_get(handshake,"id"))
{
LOG("bad handshake, no id: %s",lob_json(handshake));
lob_free(handshake);
return NULL;
}
now = util_sys_seconds();
// normalize handshake
handshake->id = now; // save when we cached it
if(!lob_get(handshake,"type")) lob_set(handshake,"type","link"); // default to link type
if(!lob_get_uint(handshake,"at")) lob_set_uint(handshake,"at",now); // require an at
LOG("handshake at %d id %s",now,lob_get(handshake,"id"));
// validate/extend link handshakes immediately
if(util_cmp(lob_get(handshake,"type"),"link") == 0)
{
// get the csid
uint8_t csid = 0;
lob_t outer;
if((outer = lob_linked(handshake)))
{
csid = outer->head[0];
}else if(lob_get(handshake,"csid")){
util_unhex(lob_get(handshake,"csid"),2,&csid);
}
if(!csid)
{
LOG("bad link handshake, no csid: %s",lob_json(handshake));
lob_free(handshake);
return NULL;
}
char hexid[3] = {0};
util_hex(&csid, 1, hexid);
// get attached hashname
lob_t tmp = lob_parse(handshake->body, handshake->body_len);
from = hashname_vkey(tmp, csid);
if(!from)
{
LOG("bad link handshake, no hashname: %s",lob_json(handshake));
lob_free(tmp);
lob_free(handshake);
return NULL;
}
lob_set(handshake,"csid",hexid);
lob_set(handshake,"hashname",hashname_char(from));
lob_set_raw(handshake,hexid,2,"true",4); // intermediate format
lob_body(handshake, tmp->body, tmp->body_len); // re-attach as raw key
lob_free(tmp);
// short-cut, if it's a key from an existing link, pass it on
// TODO: using mesh_linked here is a stack issue during loopback peer test!
if((link = mesh_linkid(mesh,from))) return link_receive_handshake(link, handshake, pipe);
LOG("no link found for handshake from %s",hashname_char(from));
// extend the key json to make it compatible w/ normal patterns
tmp = lob_new();
lob_set_base32(tmp,hexid,handshake->body,handshake->body_len);
lob_set_raw(handshake,"keys",0,(char*)tmp->head,tmp->head_len);
lob_free(tmp);
// add the path if one
if(pipe && pipe->path)
{
char *paths = malloc(pipe->path->head_len+3);
sprintf(paths,"[%.*s]",(int)pipe->path->head_len,(char*)pipe->path->head);
lob_set_raw(handshake,"paths",0,paths,pipe->path->head_len+2);
free(paths);
}
}
// always add to the front of the cached list if needed in the future
mesh->cached = lob_unshift(mesh->cached, handshake);
// tell anyone listening about the newly discovered handshake
mesh_discover(mesh, handshake, pipe);
return NULL;
}
// usually sets/updates event timer, ret if accepted/valid into receiving queue
uint8_t e3x_channel_receive(e3x_channel_t c, lob_t inner)
{
lob_t prev, miss;
uint32_t ack;
if(!c || !inner) return 1;
// TODO timer checks
if(inner == c->timer)
{
// uhoh or resend
return 1;
}
// no reliability, just append and done
if(!c->seq)
{
c->in = lob_push(c->in, inner);
return 0;
}
// reliability
inner->id = lob_get_uint(inner, "seq");
// if there's an id, it's content
if(inner->id)
{
if(inner->id <= c->acked)
{
LOG("dropping old seq %d",inner->id);
return 1;
}
// insert it sorted
prev = c->in;
while(prev && prev->id > inner->id) prev = prev->next;
if(prev && prev->id == inner->id)
{
LOG("dropping dup seq %d",inner->id);
lob_free(inner);
return 1;
}
c->in = lob_insert(c->in, prev, inner);
// LOG("inserted seq %d",c->in?c->in->id:-1);
}
// remove any from outgoing cache that have been ack'd
if((ack = lob_get_uint(inner, "ack")))
{
prev = c->out;
while(prev && prev->id <= ack)
{
c->out = lob_splice(c->out, prev);
lob_free(prev); // TODO, notify app this packet was ack'd
prev = c->out;
}
// process array, update list of packets that are missed or not
if((miss = lob_get_json(inner, "miss")))
{
// set resend flag timestamp on them
// update window
}
}
// TODO reset timer stuff
return 0;
}
