[mynewt-nimble] branch master updated: nimble/ll: Make sure that new DID is different than old one

[ja...@apache.org]

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janc pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-nimble.git


The following commit(s) were added to refs/heads/master by this push:
     new 4af2760  nimble/ll: Make sure that new DID is different than old one
     new 7d300b6  Merge pull request #304 from sjanc/did
4af2760 is described below

commit 4af2760127694ef440d30e079abb5efc9723dd4c
Author: Szymon Janc <sz...@codecoup.pl>
AuthorDate: Wed Jan 23 23:45:22 2019 +0100

    nimble/ll: Make sure that new DID is different than old one
    
    Whenever the Host provides new advertising data or scan response data
    for a given advertising set (whether it is the same as the previous
    data or not), the Advertising DID shall be updated. The new value shall
    be a randomly chosen value that is not the same as the previously used
    value.
    
    Signed-off-by: Szymon Janc <sz...@codecoup.pl>
---
 nimble/controller/src/ble_ll_adv.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/nimble/controller/src/ble_ll_adv.c b/nimble/controller/src/ble_ll_adv.c
index e2c941e..4eea78f 100644
--- a/nimble/controller/src/ble_ll_adv.c
+++ b/nimble/controller/src/ble_ll_adv.c
@@ -1549,6 +1549,26 @@ ble_ll_adv_set_adv_params(uint8_t *cmd)
     return 0;
 }
 
+#if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)
+static void
+ble_ll_adv_update_did(struct ble_ll_adv_sm *advsm)
+{
+    uint16_t old_adi = advsm->adi;
+
+    /*
+     * The Advertising DID for a given advertising set shall be initialized
+     * with a randomly chosen value. Whenever the Host provides new advertising
+     * data or scan response data for a given advertising set (whether it is the
+     * same as the previous data or not), the Advertising DID shall be updated.
+     * The new value shall be a randomly chosen value that is not the same as
+     * the previously used value.
+     */
+    do {
+        advsm->adi = (advsm->adi & 0xf000) | (rand() & 0x0fff);
+    } while (old_adi == advsm->adi);
+}
+#endif
+
 static void
 ble_ll_adv_update_adv_scan_rsp_data(struct ble_ll_adv_sm *advsm)
 {
@@ -1579,7 +1599,7 @@ ble_ll_adv_update_adv_scan_rsp_data(struct ble_ll_adv_sm *advsm)
 
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)
     /* DID shall be updated when host provides new advertising data */
-    advsm->adi = (advsm->adi & 0xf000) | (rand() & 0x0fff);
+    ble_ll_adv_update_did(advsm);
 #endif
 }
 
@@ -2095,7 +2115,7 @@ ble_ll_adv_set_scan_rsp_data(uint8_t *cmd, uint8_t cmd_len, uint8_t instance,
 
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)
         /* DID shall be updated when host provides new scan response data */
-        advsm->adi = (advsm->adi & 0xf000) | (rand() & 0x0fff);
+        ble_ll_adv_update_did(advsm);
 #endif
     }
 
@@ -2168,7 +2188,7 @@ ble_ll_adv_set_adv_data(uint8_t *cmd, uint8_t cmd_len, uint8_t instance,
         }
 
         /* update DID only */
-        advsm->adi = (advsm->adi & 0xf000) | (rand() & 0x0fff);
+        ble_ll_adv_update_did(advsm);
         return BLE_ERR_SUCCESS;
     case BLE_HCI_LE_SET_EXT_ADV_DATA_OPER_LAST:
         advsm->flags &= ~BLE_LL_ADV_SM_FLAG_ADV_DATA_INCOMPLETE;
@@ -2237,7 +2257,7 @@ ble_ll_adv_set_adv_data(uint8_t *cmd, uint8_t cmd_len, uint8_t instance,
 
 #if MYNEWT_VAL(BLE_LL_CFG_FEAT_LL_EXT_ADV)
         /* DID shall be updated when host provides new advertising data */
-        advsm->adi = (advsm->adi & 0xf000) | (rand() & 0x0fff);
+        ble_ll_adv_update_did(advsm);
 #endif
         }