core-lightning/daemon/onion.c
Rusty Russell 2610799bda pay: split into getroute and sendpay
This is less convenient to use, but makes far more sense for a real
user (like a wallet).  It can ask about the route, then decide whether
to use it or not.

This will make even more sense once we add a parameter to control how
long we let the HTLC be delayed for, so a client can query for high,
medium and low tolerances and compare results.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2016-08-31 16:06:08 +09:30

83 lines
2.0 KiB
C

#include "log.h"
#include "onion.h"
#include "peer.h"
#include "protobuf_convert.h"
#include "routing.h"
#include <string.h>
/* FIXME: http://www.cypherpunks.ca/~iang/pubs/Sphinx_Oakland09.pdf */
/* Frees r */
static const u8 *to_onion(const tal_t *ctx, const Route *r)
{
u8 *onion = tal_arr(ctx, u8, route__get_packed_size(r));
route__pack(r, onion);
tal_free(r);
return onion;
}
/* Create an onion for this path. */
const u8 *onion_create(const tal_t *ctx,
secp256k1_context *secpctx,
const struct pubkey *ids,
const u64 *amounts,
size_t num_hops)
{
Route *r = tal(ctx, Route);
size_t i;
route__init(r);
r->n_steps = num_hops + 1;
r->steps = tal_arr(r, RouteStep *, r->n_steps);
for (i = 0; i < num_hops; i++) {
r->steps[i] = tal(r, RouteStep);
route_step__init(r->steps[i]);
r->steps[i]->next_case = ROUTE_STEP__NEXT_BITCOIN;
r->steps[i]->bitcoin = pubkey_to_proto(r, secpctx, &ids[i]);
r->steps[i]->amount = amounts[i];
}
/* Now the stop marker. */
r->steps[i] = tal(r, RouteStep);
route_step__init(r->steps[i]);
r->steps[i]->next_case = ROUTE_STEP__NEXT_END;
r->steps[i]->end = true;
r->steps[i]->amount = 0;
return to_onion(ctx, r);
}
/* Decode next step in the route, and fill out the onion to send onwards. */
RouteStep *onion_unwrap(struct peer *peer,
const void *data, size_t len, const u8 **next)
{
struct ProtobufCAllocator *prototal = make_prototal(peer);
Route *r;
RouteStep *step;
r = route__unpack(prototal, len, data);
if (!r || r->n_steps == 0) {
log_unusual(peer->log, "Failed to unwrap onion");
tal_free(prototal);
return NULL;
}
/* Remove first step. */
step = r->steps[0];
/* Make sure that step owns the rest */
steal_from_prototal(peer, prototal, step);
/* Re-pack with remaining steps. */
r->n_steps--;
memmove(r->steps, r->steps + 1, sizeof(*r->steps) * r->n_steps);
if (!r->n_steps) {
*next = NULL;
tal_free(r);
} else
*next = to_onion(peer, r);
return step;
}