aljaz/lightning
1
0
Fork 0
mirror of https://github.com/aljazceru/lightning.git synced 2026-01-07 08:04:23 +01:00
Code Issues Packages Projects Releases Wiki Activity

peer: handle case correctly where they can't handle fees.

Browse Source 
When they propose an HTLC to us, they need to be able to cover both it,
and the associated fees.  When it gets acked and applied to them, however,
they may no longer be able to afford the fees; this is OK and expected.

So add a flag to say whether they can dig into fees or not: without
this patch the code calls fatal() on the next patch which tests it.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell
2016-08-31 16:06:32 +09:30
parent 1518f4424e
commit f8fa8c8dff
3 changed files with 65 additions and 57 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
daemon/channel.c
View File

@@ -90,7 +90,8 @@ static bool change_funding(uint64_t anchor_satoshis,
int64_t htlc_msat,
struct channel_oneside *a,
struct channel_oneside *b,
size_t num_nondust_htlcs)
size_t num_nondust_htlcs,
bool must_afford_fee)
{
uint64_t fee_msat;
uint64_t htlcs_total;
@@ -101,8 +102,11 @@ static bool change_funding(uint64_t anchor_satoshis,
fee_msat = calculate_fee_msat(num_nondust_htlcs, fee_rate);
/* If A is paying, can it afford it? */
if (htlc_msat > 0) {
if (htlc_msat + fee_msat / 2 > a->pay_msat + a->fee_msat)
if (htlc_msat >= 0) {
uint64_t cost = htlc_msat;
if (must_afford_fee)
cost += fee_msat / 2;
if (cost > a->pay_msat + a->fee_msat)
return false;
}
@@ -148,7 +152,7 @@ struct channel_state *initial_cstate(const tal_t *ctx,
funder->fee_msat = fee_msat;
/* Make sure it checks out. */
assert(change_funding(anchor_satoshis, fee_rate, 0, funder, fundee, 0));
assert(change_funding(anchor_satoshis, fee_rate, 0, funder, fundee, 0, false));
assert(funder->fee_msat == fee_msat);
assert(fundee->fee_msat == 0);
@@ -194,7 +198,8 @@ bool force_fee(struct channel_state *cstate, uint64_t fee)
}
/* Add a HTLC to @creator if it can afford it. */
bool cstate_add_htlc(struct channel_state *cstate, const struct htlc *htlc)
bool cstate_add_htlc(struct channel_state *cstate, const struct htlc *htlc,
bool must_afford_fee)
{
size_t nondust;
struct channel_oneside *creator, *recipient;
@@ -208,7 +213,8 @@ bool cstate_add_htlc(struct channel_state *cstate, const struct htlc *htlc)
nondust++;
if (!change_funding(cstate->anchor, cstate->fee_rate,
htlc->msatoshis, creator, recipient, nondust))
htlc->msatoshis, creator, recipient, nondust,
must_afford_fee))
return false;
cstate->num_nondust = nondust;
@@ -235,7 +241,7 @@ static void remove_htlc(struct channel_state *cstate,
if (!change_funding(cstate->anchor, cstate->fee_rate,
-(int64_t)htlc->msatoshis,
&cstate->side[beneficiary],
&cstate->side[!beneficiary], nondust))
&cstate->side[!beneficiary], nondust, false))
abort();
/* Actually remove the HTLC. */