Return-Path: MIME-Version: 1.0 In-Reply-To: <5548555.j9qucFdfti@uw000953> References: <1424943583-30061-1-git-send-email-lukasz.rymanowski@tieto.com> <1424943583-30061-16-git-send-email-lukasz.rymanowski@tieto.com> <5548555.j9qucFdfti@uw000953> Date: Fri, 27 Feb 2015 16:14:42 +0100 Message-ID: Subject: Re: [PATCH 15/16] shared/gatt-helpers: Improve robustness read by type request From: Lukasz Rymanowski To: Szymon Janc Cc: Lukasz Rymanowski , "linux-bluetooth@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Szymon, On Fri, Feb 27, 2015 at 4:07 PM, Szymon Janc wrote: > Hi Łukasz, > > On Thursday 26 of February 2015 10:39:42 Lukasz Rymanowski wrote: >> This patch makes sure that we do get into infinite loop when doing >> read by type request. >> >> It could happen if we got bogus read by type response >> --- >> src/shared/gatt-helpers.c | 15 ++++++++++++++- >> 1 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/src/shared/gatt-helpers.c b/src/shared/gatt-helpers.c >> index 8858e58..6e5cf30 100644 >> --- a/src/shared/gatt-helpers.c >> +++ b/src/shared/gatt-helpers.c >> @@ -1331,10 +1331,22 @@ static void read_by_type_cb(uint8_t opcode, const void *pdu, >> } >> >> last_handle = get_le16(pdu + length - data_length); >> + >> + /* >> + * If last handle is lower from previous start handle then it is smth >> + * wrong. Let's stop search, otherwise we might enter infinite loop. >> + */ >> + if (last_handle < op->start_handle) { >> + success = true; >> + goto done; >> + } > > Shouldn't this be success = false ? True, my bad. Can you fix that or should I send v2? > >> + >> + op->start_handle = last_handle + 1; >> + >> if (last_handle != op->end_handle) { >> uint8_t pdu[4 + get_uuid_len(&op->uuid)]; >> >> - put_le16(last_handle + 1, pdu); >> + put_le16(op->start_handle, pdu); >> put_le16(op->end_handle, pdu + 2); >> bt_uuid_to_le(&op->uuid, pdu + 4); >> >> @@ -1376,6 +1388,7 @@ bool bt_gatt_read_by_type(struct bt_att *att, uint16_t start, uint16_t end, >> op->callback = callback; >> op->user_data = user_data; >> op->destroy = destroy; >> + op->start_handle = start; >> op->end_handle = end; >> op->uuid = *uuid; >> >> > > -- > Best regards, > Szymon Janc > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html