lightningd: fix crash when failing htlc once channeld dies.

We were reaching through it to get `ld`, but channeld is already dead.
Caught this on test_onchaind_replay (without valgrind) on my test machine:

    INFO 0266e4598d1d3c415f572a8488830b60f7e744ed9235eb0b1ba93283b315c03518-chan#1: Peer transient failure in CHANNELD_NORMAL: channeld: Owning subdaemon channeld died (62208)
    **BROKEN** lightningd: FATAL SIGNAL 11 (version f6e1735)
    **BROKEN** lightningd: backtrace: common/daemon.c:44 (send_backtrace) 0x5634dc83dc55
    **BROKEN** lightningd: backtrace: common/daemon.c:52 (crashdump) 0x5634dc83dca9
    **BROKEN** lightningd: backtrace: (null):0 ((null)) 0x7fd4b7c0b46f
    **BROKEN** lightningd: backtrace: lightningd/peer_htlcs.c:285 (failmsg_incorrect_or_unknown) 0x5634dc82625a
    **BROKEN** lightningd: backtrace: lightningd/htlc_set.c:109 (htlc_set_add) 0x5634dc801e5c
    **BROKEN** lightningd: backtrace: lightningd/peer_htlcs.c:496 (handle_localpay) 0x5634dc826997
    **BROKEN** lightningd: backtrace: lightningd/peer_htlcs.c:1008 (htlc_accepted_hook_callback) 0x5634dc827e60
    **BROKEN** lightningd: backtrace: lightningd/plugin_hook.c:197 (plugin_hook_callback) 0x5634dc831ea1
    **BROKEN** lightningd: backtrace: lightningd/plugin.c:261 (plugin_response_handle) 0x5634dc82d2c3
    **BROKEN** lightningd: backtrace: lightningd/plugin.c:359 (plugin_read_json_one) 0x5634dc82d46f
    **BROKEN** lightningd: backtrace: lightningd/plugin.c:391 (plugin_read_json) 0x5634dc82d5c6
    **BROKEN** lightningd: backtrace: ccan/ccan/io/io.c:59 (next_plan) 0x5634dc896319
    **BROKEN** lightningd: backtrace: ccan/ccan/io/io.c:407 (do_plan) 0x5634dc896efe
    **BROKEN** lightningd: backtrace: ccan/ccan/io/io.c:417 (io_ready) 0x5634dc896f40
   
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/htlc_set.c

@@ -106,7 +106,7 @@ void htlc_set_add(struct lightningd *ld,
 					total_msat, payment_secret);
 	if (!details) {
 		local_fail_in_htlc(hin,
-				   take(failmsg_incorrect_or_unknown(NULL, hin)));
+				   take(failmsg_incorrect_or_unknown(NULL, ld, hin)));
 		return;
 	}
 
@@ -130,7 +130,7 @@ void htlc_set_add(struct lightningd *ld,
 		/* We check this now, since we want to fail with this as soon
 		 * as possible, to avoid other probing attacks. */
 		if (!payment_secret) {
-			local_fail_in_htlc(hin, take(failmsg_incorrect_or_unknown(NULL, hin)));
+			local_fail_in_htlc(hin, take(failmsg_incorrect_or_unknown(NULL, ld, hin)));
 			return;
 		}
 		tal_arr_expand(&set->htlcs, hin);
@@ -193,7 +193,7 @@ void htlc_set_add(struct lightningd *ld,
 	/* This catches the case of the first payment in a set. */
 	if (!payment_secret) {
 		htlc_set_fail(set,
-			      take(failmsg_incorrect_or_unknown(NULL, hin)));
+			      take(failmsg_incorrect_or_unknown(NULL, ld, hin)));
 		return;
 	}
 }

lightningd/invoice.c

@@ -163,7 +163,7 @@ static void invoice_payload_remove_set(struct htlc_set *set,
 }
 
 static const u8 *hook_gives_failmsg(const tal_t *ctx,
-				    struct log *log,
+				    struct lightningd *ld,
 				    const struct htlc_in *hin,
 				    const char *buffer,
 				    const jsmntok_t *toks)
@@ -181,7 +181,7 @@ static const u8 *hook_gives_failmsg(const tal_t *ctx,
 		if (json_tok_streq(buffer, resulttok, "continue")) {
 			return NULL;
 		} else if (json_tok_streq(buffer, resulttok, "reject")) {
-			return failmsg_incorrect_or_unknown(ctx, hin);
+			return failmsg_incorrect_or_unknown(ctx, ld, hin);
 		} else
 			fatal("Invalid invoice_payment hook result: %.*s",
 			      toks[0].end - toks[0].start, buffer);
@@ -204,7 +204,7 @@ static const u8 *hook_gives_failmsg(const tal_t *ctx,
 		static bool warned = false;
 		if (!warned) {
 			warned = true;
-			log_unusual(log,
+			log_unusual(ld->log,
 				    "Plugin did not return object with "
 				    "'result' or 'failure_message' fields.  "
 				    "This is now deprecated and you should "
@@ -212,7 +212,7 @@ static const u8 *hook_gives_failmsg(const tal_t *ctx,
 				    "{'result': 'reject'} or "
 				    "{'failure_message'... instead.");
 		}
-		return failmsg_incorrect_or_unknown(ctx, hin);
+		return failmsg_incorrect_or_unknown(ctx, ld, hin);
 	}
 
 	if (!json_to_number(buffer, t, &val))
@@ -227,7 +227,7 @@ static const u8 *hook_gives_failmsg(const tal_t *ctx,
 			   " changing to incorrect_or_unknown_payment_details",
 			   val);
 
-	return failmsg_incorrect_or_unknown(ctx, hin);
+	return failmsg_incorrect_or_unknown(ctx, ld, hin);
 }
 
 static void
@@ -258,12 +258,12 @@ invoice_payment_hook_cb(struct invoice_payment_hook_payload *payload,
 	 * we can also fail */
 	if (!wallet_invoice_find_by_label(ld->wallet, &invoice, payload->label)) {
 		htlc_set_fail(payload->set, take(failmsg_incorrect_or_unknown(
-							 NULL, payload->set->htlcs[0])));
+							 NULL, ld, payload->set->htlcs[0])));
 		return;
 	}
 
 	/* Did we have a hook result? */
-	failmsg = hook_gives_failmsg(NULL, ld->log,
+	failmsg = hook_gives_failmsg(NULL, ld,
 				     payload->set->htlcs[0], buffer, toks);
 	if (failmsg) {
 		htlc_set_fail(payload->set, take(failmsg));

lightningd/peer_htlcs.c

@@ -278,11 +278,12 @@ void local_fail_in_htlc_needs_update(struct htlc_in *hin,
 
 /* Helper to create (common) WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS */
 const u8 *failmsg_incorrect_or_unknown(const tal_t *ctx,
+				       struct lightningd *ld,
 				       const struct htlc_in *hin)
 {
 	return towire_incorrect_or_unknown_payment_details(
 		ctx, hin->msat,
-		get_block_height(hin->key.channel->owner->ld->topology));
+		get_block_height(ld->topology));
 }
 
 /* localfail are for handing to the local payer if it's local. */
@@ -489,7 +490,7 @@ static void handle_localpay(struct htlc_in *hin,
 			  hin->cltv_expiry,
 			  get_block_height(ld->topology),
 			  ld->config.cltv_final);
-		failmsg = failmsg_incorrect_or_unknown(NULL, hin);
+		failmsg = failmsg_incorrect_or_unknown(NULL, ld, hin);
 		goto fail;
 	}
 

lightningd/peer_htlcs.h

@@ -82,5 +82,6 @@ void json_format_forwarding_object(struct json_stream *response, const char *fie
 
 /* Helper to create (common) WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS */
 const u8 *failmsg_incorrect_or_unknown(const tal_t *ctx,
+				       struct lightningd *ld,
 				       const struct htlc_in *hin);
 #endif /* LIGHTNING_LIGHTNINGD_PEER_HTLCS_H */

lightningd/test/run-invoice-select-inchan.c

@@ -92,6 +92,7 @@ char *encode_scriptpubkey_to_addr(const tal_t *ctx UNNEEDED,
 { fprintf(stderr, "encode_scriptpubkey_to_addr called!\n"); abort(); }
 /* Generated stub for failmsg_incorrect_or_unknown */
 const u8 *failmsg_incorrect_or_unknown(const tal_t *ctx UNNEEDED,
+				       struct lightningd *ld UNNEEDED,
 				       const struct htlc_in *hin UNNEEDED)
 { fprintf(stderr, "failmsg_incorrect_or_unknown called!\n"); abort(); }
 /* Generated stub for fatal */