From: Archie Pusaka <apusaka@chromium.org>
Date: Thu, 25 Nov 2021 15:04:37 +0800
Subject: Bluetooth: Limit duration of Remote Name Resolve
Patch-mainline: v5.17-rc1
Git-commit: dbf6811abbfcc79d3cd5ce1ff53fe1c741167a1f
References: jsc#PED-1407
When doing remote name request, we cannot scan. In the normal case it's
OK since we can expect it to finish within a short amount of time.
However, there is a possibility to scan lots of devices that
(1) requires Remote Name Resolve
(2) is unresponsive to Remote Name Resolve
When this happens, we are stuck to do Remote Name Resolve until all is
done before continue scanning.
This patch adds a time limit to stop us spending too long on remote
name request.
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
include/net/bluetooth/hci_core.h | 3 +++
net/bluetooth/hci_event.c | 7 +++++++
2 files changed, 10 insertions(+)
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -88,6 +88,7 @@ struct discovery_state {
u8 (*uuids)[16];
unsigned long scan_start;
unsigned long scan_duration;
+ unsigned long name_resolve_timeout;
};
#define SUSPEND_NOTIFIER_TIMEOUT msecs_to_jiffies(2000) /* 2 seconds */
@@ -1759,6 +1760,8 @@ void hci_mgmt_chan_unregister(struct hci
#define DISCOV_LE_FAST_ADV_INT_MIN 0x00A0 /* 100 msec */
#define DISCOV_LE_FAST_ADV_INT_MAX 0x00F0 /* 150 msec */
+#define NAME_RESOLVE_DURATION msecs_to_jiffies(10240) /* 10.24 sec */
+
void mgmt_fill_version_info(void *ver);
int mgmt_new_settings(struct hci_dev *hdev);
void mgmt_index_added(struct hci_dev *hdev);
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2129,6 +2129,12 @@ static bool hci_resolve_next_name(struct
if (list_empty(&discov->resolve))
return false;
+ /* We should stop if we already spent too much time resolving names. */
+ if (time_after(jiffies, discov->name_resolve_timeout)) {
+ bt_dev_warn_ratelimited(hdev, "Name resolve takes too long.");
+ return false;
+ }
+
e = hci_inquiry_cache_lookup_resolve(hdev, BDADDR_ANY, NAME_NEEDED);
if (!e)
return false;
@@ -2716,6 +2722,7 @@ static void hci_inquiry_complete_evt(str
if (e && hci_resolve_name(hdev, e) == 0) {
e->name_state = NAME_PENDING;
hci_discovery_set_state(hdev, DISCOVERY_RESOLVING);
+ discov->name_resolve_timeout = jiffies + NAME_RESOLVE_DURATION;
} else {
/* When BR/EDR inquiry is active and no LE scanning is in
* progress, then change discovery state to indicate completion.