From 38535fc36c9e1061266d6fadc555ee995a75057d Mon Sep 17 00:00:00 2001
From: ZmnSCPxj <ZmnSCPxj@protonmail.com>
Date: Sat, 17 Feb 2018 07:34:31 +0000
Subject: [PATCH] payalgo: Create a new failure for paying expired invoice.

---
 doc/lightning-pay.7         | 21 +++++++++++++++++++--
 doc/lightning-pay.7.txt     |  5 +++++
 lightningd/jsonrpc_errors.h |  1 +
 lightningd/payalgo.c        | 35 ++++++++++++++++++++++-------------
 4 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/doc/lightning-pay.7 b/doc/lightning-pay.7
index c64c94114..c0cbfc099 100644
--- a/doc/lightning-pay.7
+++ b/doc/lightning-pay.7
@@ -2,12 +2,12 @@
 .\"     Title: lightning-pay
 .\"    Author: [see the "AUTHOR" section]
 .\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
-.\"      Date: 02/11/2018
+.\"      Date: 02/17/2018
 .\"    Manual: \ \&
 .\"    Source: \ \&
 .\"  Language: English
 .\"
-.TH "LIGHTNING\-PAY" "7" "02/11/2018" "\ \&" "\ \&"
+.TH "LIGHTNING\-PAY" "7" "02/17/2018" "\ \&" "\ \&"
 .\" -----------------------------------------------------------------
 .\" * Define some portability stuff
 .\" -----------------------------------------------------------------
@@ -155,6 +155,23 @@ as well as the
 percentage that the fee has of the destination payment amount\&.
 .RE
 .sp
+.RS 4
+.ie n \{\
+\h'-04'\(bu\h'+03'\c
+.\}
+.el \{\
+.sp -1
+.IP \(bu 2.3
+.\}
+207\&. Invoice expired\&. Payment took too long before expiration, or already expired at the time you initiated payment\&. The
+\fIdata\fR
+field of the error indicates
+\fInow\fR
+(the current time) and
+\fIexpiry\fR
+(the invoice expiration) as UNIX epoch time in seconds\&.
+.RE
+.sp
 A routing failure object has the fields below:
 .sp
 .RS 4
diff --git a/doc/lightning-pay.7.txt b/doc/lightning-pay.7.txt
index 405bc04d3..a9b019c39 100644
--- a/doc/lightning-pay.7.txt
+++ b/doc/lightning-pay.7.txt
@@ -60,6 +60,11 @@ The following error codes may occur:
   indicate the actual 'fee' as well as the 'feepercent'
   percentage that the fee has of the destination payment
   amount.
+* 207. Invoice expired. Payment took too long before expiration,
+  or already expired at the time you initiated payment.
+  The 'data' field of the error indicates 'now' (the current time)
+  and 'expiry' (the invoice expiration) as UNIX epoch time in
+  seconds.
 
 A routing failure object has the fields below:
 
diff --git a/lightningd/jsonrpc_errors.h b/lightningd/jsonrpc_errors.h
index 8e0a27387..060cb90ec 100644
--- a/lightningd/jsonrpc_errors.h
+++ b/lightningd/jsonrpc_errors.h
@@ -18,5 +18,6 @@
 #define PAY_TRY_OTHER_ROUTE		204
 #define PAY_ROUTE_NOT_FOUND		205
 #define PAY_ROUTE_TOO_EXPENSIVE		206
+#define PAY_INVOICE_EXPIRED             207
 
 #endif /* !defined (LIGHTNING_LIGHTNINGD_JSONRPC_ERRORS_H) */
diff --git a/lightningd/payalgo.c b/lightningd/payalgo.c
index b109099c0..83e2c72d8 100644
--- a/lightningd/payalgo.c
+++ b/lightningd/payalgo.c
@@ -113,14 +113,13 @@ static void json_pay_failure(struct command *cmd,
 }
 
 /* Start a payment attempt. */
-static void json_pay_try(struct pay *pay);
+static bool json_pay_try(struct pay *pay);
 
 /* Call when sendpay returns to us. */
 static void json_pay_sendpay_resolve(const struct sendpay_result *r,
 				     void *vpay)
 {
 	struct pay *pay = (struct pay *) vpay;
-	struct timeabs now = time_now();
 
 	/* If we succeed, hurray */
 	if (r->succeeded) {
@@ -136,13 +135,6 @@ static void json_pay_sendpay_resolve(const struct sendpay_result *r,
 		return;
 	}
 
-	/* If too late anyway, fail now. */
-	if (time_after(now, pay->expiry)) {
-		/* FIXME: maybe another error kind? */
-		json_pay_failure(pay->cmd, r);
-		return;
-	}
-
 	json_pay_try(pay);
 }
 
@@ -199,11 +191,26 @@ static void json_pay_getroute_reply(struct subd *gossip,
 		     &json_pay_sendpay_resolve, pay);
 }
 
-/* Start a payment attempt */
-static void json_pay_try(struct pay *pay)
+/* Start a payment attempt. Return true if deferred,
+ * false if resolved now. */
+static bool json_pay_try(struct pay *pay)
 {
 	u8 *req;
 	struct command *cmd = pay->cmd;
+	struct timeabs now = time_now();
+	struct json_result *data;
+
+	/* If too late anyway, fail now. */
+	if (time_after(now, pay->expiry)) {
+		data = new_json_result(cmd);
+		json_object_start(data, NULL);
+		json_add_num(data, "now", now.ts.tv_sec);
+		json_add_num(data, "expiry", pay->expiry.ts.tv_sec);
+		json_object_end(data);
+		command_fail_detailed(cmd, PAY_INVOICE_EXPIRED, data,
+				      "Invoice expired");
+		return false;
+	}
 
 	/* Clear previous sendpay. */
 	pay->sendpay_parent = tal_free(pay->sendpay_parent);
@@ -218,6 +225,8 @@ static void json_pay_try(struct pay *pay)
 					     pay->riskfactor,
 					     pay->min_final_cltv_expiry);
 	subd_req(pay, cmd->ld->gossip, req, -1, 0, json_pay_getroute_reply, pay);
+
+	return true;
 }
 
 static void json_pay(struct command *cmd,
@@ -316,8 +325,8 @@ static void json_pay(struct command *cmd,
 	pay->sendpay_parent = NULL;
 
 	/* Initiate payment */
-	json_pay_try(pay);
-	command_still_pending(cmd);
+	if (json_pay_try(pay))
+		command_still_pending(cmd);
 }
 
 static const struct json_command pay_command = {