Bluetooth: SMP: Improve logging of unspecified pairing failure

Improve logging of pairing procedure when it fails with error code
unspecified. Since this is returned in many places debugging this
failure is not easy without adding additional debugging.

Signed-off-by: Joakim Andersson <[email protected]>

Author: joerchan

subsys/bluetooth/host/smp.c

@@ -1107,7 +1107,7 @@ static void smp_br_derive_ltk(struct bt_smp_br *smp)
 
 	keys = bt_keys_get_type(BT_KEYS_LTK_P256, conn->id, &addr);
 	if (!keys) {
-		BT_ERR("No keys space for %s", bt_addr_le_str(&addr));
+		BT_ERR("Unable to get keys for %s", bt_addr_le_str(&addr));
 		return;
 	}
 
@@ -1305,6 +1305,7 @@ static uint8_t smp_br_pairing_req(struct bt_smp_br *smp, struct net_buf *buf)
 
 	max_key_size = bt_conn_enc_key_size(conn);
 	if (!max_key_size) {
+		BT_DBG("Invalid encryption key size");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -1377,6 +1378,7 @@ static uint8_t smp_br_pairing_rsp(struct bt_smp_br *smp, struct net_buf *buf)
 
 	max_key_size = bt_conn_enc_key_size(conn);
 	if (!max_key_size) {
+		BT_DBG("Invalid encryption key size");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -1743,6 +1745,7 @@ int bt_smp_br_send_pairing_req(struct bt_conn *conn)
 
 	max_key_size = bt_conn_enc_key_size(conn);
 	if (!max_key_size) {
+		BT_DBG("Invalid encryption key size");
 		return -EIO;
 	}
 
@@ -2007,6 +2010,7 @@ static uint8_t smp_send_pairing_confirm(struct bt_smp *smp)
 		r |= 0x80;
 		break;
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -2459,6 +2463,7 @@ static uint8_t legacy_pairing_random(struct bt_smp *smp)
 	if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
 		err = smp_s1(smp->tk, smp->prnd, smp->rrnd, tmp);
 		if (err) {
+			BT_ERR("Calculate STK failed");
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 
@@ -2889,6 +2894,8 @@ static uint8_t smp_pairing_req(struct bt_smp *smp, struct net_buf *buf)
 	if (!conn->le.keys) {
 		conn->le.keys = bt_keys_get_addr(conn->id, &conn->le.dst);
 		if (!conn->le.keys) {
+			BT_DBG("Unable to get keys for %s",
+			       bt_addr_le_str(&conn->le.dst));
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 	}
@@ -2941,6 +2948,7 @@ static uint8_t smp_pairing_req(struct bt_smp *smp, struct net_buf *buf)
 		atomic_set_bit(smp->flags, SMP_FLAG_BOND);
 	} else if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED)) {
 		/* Reject pairing req if not both intend to bond */
+		BT_DBG("Bonding required");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3144,6 +3152,7 @@ static uint8_t smp_pairing_rsp(struct bt_smp *smp, struct net_buf *buf)
 		atomic_set_bit(smp->flags, SMP_FLAG_BOND);
 	} else if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED)) {
 		/* Reject pairing req if not both intend to bond */
+		BT_DBG("Bonding required");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3261,6 +3270,7 @@ static uint8_t smp_pairing_confirm(struct bt_smp *smp, struct net_buf *buf)
 	case JUST_WORKS:
 	case PASSKEY_CONFIRM:
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 }
@@ -3306,6 +3316,7 @@ static uint8_t compute_and_send_master_dhcheck(struct bt_smp *smp)
 		}
 		break;
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3314,12 +3325,14 @@ static uint8_t compute_and_send_master_dhcheck(struct bt_smp *smp)
 		   &smp->chan.chan.conn->le.init_addr,
 		   &smp->chan.chan.conn->le.resp_addr, smp->mackey,
 		   smp->tk)) {
+		BT_ERR("Calculate LTK failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 	/* calculate local DHKey check */
 	if (smp_f6(smp->mackey, smp->prnd, smp->rrnd, r, &smp->preq[1],
 		   &smp->chan.chan.conn->le.init_addr,
 		   &smp->chan.chan.conn->le.resp_addr, e)) {
+		BT_ERR("Calculate local DHKey check failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3350,6 +3363,7 @@ static uint8_t compute_and_check_and_send_slave_dhcheck(struct bt_smp *smp)
 		}
 		break;
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3358,13 +3372,15 @@ static uint8_t compute_and_check_and_send_slave_dhcheck(struct bt_smp *smp)
 		   &smp->chan.chan.conn->le.init_addr,
 		   &smp->chan.chan.conn->le.resp_addr, smp->mackey,
 		   smp->tk)) {
+		BT_ERR("Calculate LTK failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
 	/* calculate local DHKey check */
 	if (smp_f6(smp->mackey, smp->prnd, smp->rrnd, r, &smp->prsp[1],
 		   &smp->chan.chan.conn->le.resp_addr,
 		   &smp->chan.chan.conn->le.init_addr, e)) {
+		BT_ERR("Calculate local DHKey check failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3380,6 +3396,7 @@ static uint8_t compute_and_check_and_send_slave_dhcheck(struct bt_smp *smp)
 	if (smp_f6(smp->mackey, smp->rrnd, smp->prnd, r, &smp->preq[1],
 		   &smp->chan.chan.conn->le.init_addr,
 		   &smp->chan.chan.conn->le.resp_addr, re)) {
+		BT_ERR("Calculate remote DHKey check failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3515,10 +3532,12 @@ static uint8_t sc_smp_check_confirm(struct bt_smp *smp)
 		r |= 0x80;
 		break;
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
 	if (smp_f4(smp->pkey, sc_public_key, smp->rrnd, r, cfm)) {
+		BT_ERR("Calculate confirm failed");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3631,6 +3650,7 @@ static uint8_t smp_pairing_random(struct bt_smp *smp, struct net_buf *buf)
 				       BT_SMP_CMD_PAIRING_CONFIRM);
 			return smp_send_pairing_confirm(smp);
 		default:
+			BT_ERR("Unknown pairing method (%u)", smp->method);
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 
@@ -3708,6 +3728,7 @@ static uint8_t smp_pairing_random(struct bt_smp *smp, struct net_buf *buf)
 			return BT_SMP_ERR_OOB_NOT_AVAIL;
 		}
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3924,6 +3945,7 @@ static uint8_t smp_security_request(struct bt_smp *smp, struct net_buf *buf)
 	if (IS_ENABLED(CONFIG_BT_BONDING_REQUIRED) &&
 	    !(bondable && (auth & BT_SMP_AUTH_BONDING))) {
 		/* Reject security req if not both intend to bond */
+		BT_DBG("Bonding required");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -3970,6 +3992,7 @@ static uint8_t smp_security_request(struct bt_smp *smp, struct net_buf *buf)
 					conn->le.keys->ltk.ediv,
 					conn->le.keys->ltk.val,
 					conn->le.keys->enc_size) < 0) {
+		BT_ERR("Failed to start encryption");
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -4068,6 +4091,7 @@ static uint8_t smp_public_key_slave(struct bt_smp *smp)
 		atomic_set_bit(&smp->allowed_cmds, BT_SMP_CMD_PAIRING_RANDOM);
 		break;
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return BT_SMP_ERR_UNSPECIFIED;
 	}
 
@@ -4157,6 +4181,7 @@ static uint8_t smp_public_key(struct bt_smp *smp, struct net_buf *buf)
 			}
 			break;
 		default:
+			BT_ERR("Unknown pairing method (%u)", smp->method);
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 
@@ -4205,6 +4230,7 @@ static uint8_t smp_dhkey_check(struct bt_smp *smp, struct net_buf *buf)
 			}
 			break;
 		default:
+			BT_ERR("Unknown pairing method (%u)", smp->method);
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 
@@ -4226,6 +4252,7 @@ static uint8_t smp_dhkey_check(struct bt_smp *smp, struct net_buf *buf)
 		(void)memset(rand, 0, sizeof(rand));
 		if (bt_conn_le_start_encryption(smp->chan.chan.conn, rand, ediv,
 						smp->tk, enc_size) < 0) {
+			BT_ERR("Failed to start encryption");
 			return BT_SMP_ERR_UNSPECIFIED;
 		}
 
@@ -5357,6 +5384,8 @@ int bt_smp_auth_cancel(struct bt_conn *conn)
 		return -EINVAL;
 	}
 
+	BT_DBG("");
+
 	switch (smp->method) {
 	case PASSKEY_INPUT:
 	case PASSKEY_DISPLAY:
@@ -5369,6 +5398,7 @@ int bt_smp_auth_cancel(struct bt_conn *conn)
 	case JUST_WORKS:
 		return smp_error(smp, BT_SMP_ERR_UNSPECIFIED);
 	default:
+		BT_ERR("Unknown pairing method (%u)", smp->method);
 		return 0;
 	}
 }