// must be called after every send or receive, pass pkt to e3x_encrypt before sending
lob_t e3x_channel_sending(e3x_channel_t c)
{
lob_t ret;
uint32_t now;
if(!c) return NULL;
// packets waiting
if(c->out)
{
ret = lob_shift(c->out);
c->out = ret->next;
// if it's a content packet and reliable, add to sent list
if(c->seq && ret->id) c->sent = lob_push(c->sent, lob_copy(ret));
return ret;
}
// check sent list for any flagged to resend
now = util_sys_seconds();
for(ret = c->sent; ret; ret = ret->next)
{
if(!ret->id) continue;
if(ret->id == now) continue;
// max once per second throttle resend
ret->id = now;
return ret;
}
LOG("sending ack %d acked %d",c->ack,c->acked);
// if we need to generate an ack/miss yet, do that
if(c->ack != c->acked) return e3x_channel_oob(c);
return NULL;
}
// this will set the default inactivity timeout using this event timer and our uid
uint32_t e3x_channel_timeout(e3x_channel_t c, e3x_event_t ev, uint32_t timeout)
{
if(!c) return 0;
// un-set any
if(ev != c->ev)
{
// cancel and clearn any previous timer state
c->timeout = 0;
if(c->ev) e3x_event_set(c->ev,NULL,c->uid,0);
c->ev = NULL;
lob_free(c->timer);
c->timer = NULL;
}
// no event manager, no timeouts
if(!ev) return 0;
// no timeout, just return how much time is left
if(!timeout) return _time_left(c);
// add/update new timeout
c->tsince = util_sys_seconds(); // start timer now
c->timeout = timeout;
c->ev = ev;
c->timer = lob_new();
lob_set_uint(c->timer,"c",c->id);
lob_set(c->timer, "id", c->uid);
lob_set(c->timer, "err", "timeout");
e3x_event_set(c->ev, c->timer, lob_get(c->timer, "id"), timeout*1000); // ms in the future
return _time_left(c);
}
// internally calculate until timeout
uint32_t _time_left(e3x_channel_t c)
{
uint32_t at = util_sys_seconds();
if(!c) return 0;
if(!c->timeout) return 1; // never timeout
// some seconds left yet
if((at - c->tsince) < c->timeout) return c->timeout - (at - c->tsince);
return 0;
}
uint64_t util_at(void)
{
uint64_t at;
uint32_t *half = (uint32_t*)(&at);
// store both current seconds and ms since then in one value
half[0] = util_sys_seconds();
half[1] = (uint32_t)util_sys_ms(half[0]);
return at;
}
// load in the key to existing link
link_t link_load(link_t link, uint8_t csid, lob_t key)
{
char hex[3];
lob_t copy;
if(!link || !csid || !key) return LOG("bad args");
if(link->x)
{
link->csid = link->x->csid; // repair in case mesh_unlink was called, any better place?
return link;
}
LOG("adding %x key to link %s",csid,hashname_short(link->id));
// key must be bin
if(key->body_len)
{
copy = lob_new();
lob_body(copy,key->body,key->body_len);
}else{
util_hex(&csid,1,hex);
copy = lob_get_base32(key,hex);
}
link->x = e3x_exchange_new(link->mesh->self, csid, copy);
if(!link->x)
{
LOG("invalid %x key %s %s",csid,util_hex(copy->body,copy->body_len,NULL),lob_json(key));
lob_free(copy);
return NULL;
}
link->csid = csid;
link->key = copy;
e3x_exchange_out(link->x, util_sys_seconds());
LOG("new exchange session to %s",hashname_short(link->id));
return link;
}
// load in the key to existing link
link_t link_load(link_t link, uint8_t csid, lob_t key)
{
char hex[3];
lob_t copy;
if(!link || !csid || !key) return LOG("bad args");
if(link->x) return link;
LOG("adding %x key to link %s",csid,link->id->hashname);
// key must be bin
if(key->body_len)
{
copy = lob_copy(key);
}else{
util_hex(&csid,1,hex);
copy = lob_get_base32(key,hex);
}
link->x = e3x_exchange_new(link->mesh->self, csid, copy);
if(!link->x)
{
lob_free(copy);
return LOG("invalid %x key %d %s",csid,key->body_len,lob_json(key));
}
link->csid = csid;
link->key = copy;
// route packets to this token
util_hex(e3x_exchange_token(link->x),16,link->token);
xht_set(link->mesh->index,link->token,link);
e3x_exchange_out(link->x, util_sys_seconds());
LOG("new session token %s to %s",link->token,link->id->hashname);
return link;
}
// 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;
}
