This adds struct bt_ad_pattern and helpers functions to facilitate
pattern matching.
Reviewed-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
Reviewed-by: Sonny Sasaka <sonnysasaka@xxxxxxxxxxxx>
Reviewed-by: Howard Chung <howardchung@xxxxxxxxxx>
---
Changes in v8:
- Modify signature of ad_replace_data() to avoid memory copy
src/shared/ad.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++-
src/shared/ad.h | 16 +++++
2 files changed, 166 insertions(+), 1 deletion(-)
diff --git a/src/shared/ad.c b/src/shared/ad.c
index a34d7a147..23c8c34f4 100644
--- a/src/shared/ad.c
+++ b/src/shared/ad.c
@@ -31,6 +31,12 @@ struct bt_ad {
struct queue *data;
};
+struct pattern_match_info {
+ struct bt_ad *ad;
+ struct bt_ad_pattern *current_pattern;
+ struct bt_ad_pattern *matched_pattern;
+};
+
struct bt_ad *bt_ad_new(void)
{
struct bt_ad *ad;
@@ -46,6 +52,65 @@ struct bt_ad *bt_ad_new(void)
return bt_ad_ref(ad);
}
+static bool ad_replace_data(struct bt_ad *ad, uint8_t type, const void *data,
+ size_t len);
+
+static bool ad_is_type_valid(uint8_t type)
+{
+ if (type > BT_AD_3D_INFO_DATA && type != BT_AD_MANUFACTURER_DATA)
+ return false;
+ if (type < BT_AD_FLAGS)
+ return false;
+
+ return true;
+}
+
+struct bt_ad *bt_ad_new_with_data(size_t len, const uint8_t *data)
+{
+ struct bt_ad *ad;
+ uint16_t parsed_len = 0;
+
+ if (data == NULL || !len)
+ return NULL;
+
+ ad = bt_ad_new();
+ if (!ad)
+ return NULL;
+
+ while (parsed_len < len - 1) {
+ uint8_t d_len;
+ uint8_t d_type;
+ const uint8_t *d;
+ uint8_t field_len = data[0];
+
+ if (field_len == 0)
+ break;
+
+ parsed_len += field_len + 1;
+
+ if (parsed_len > len)
+ break;
+
+ d = &data[2];
+ d_type = data[1];
+ d_len = field_len - 1;
+
+ if (!ad_is_type_valid(d_type))
+ goto failed;
+
+ if (!ad_replace_data(ad, d_type, d, d_len))
+ goto failed;
+
+ data += field_len + 1;
+ }
+
+ return ad;
+
+failed:
+ bt_ad_unref(ad);
+ return NULL;
+}
+
struct bt_ad *bt_ad_ref(struct bt_ad *ad)
{
if (!ad)
@@ -126,7 +191,7 @@ static bool data_type_match(const void *data, const void *user_data)
return a->type == type;
}
-static bool ad_replace_data(struct bt_ad *ad, uint8_t type, void *data,
+static bool ad_replace_data(struct bt_ad *ad, uint8_t type, const void *data,
size_t len)
{
struct bt_ad_data *new_data;
@@ -994,3 +1059,87 @@ void bt_ad_clear_data(struct bt_ad *ad)
queue_remove_all(ad->data, NULL, NULL, data_destroy);
}
+
+struct bt_ad_pattern *bt_ad_pattern_new(uint8_t type, size_t offset, size_t len,
+ const uint8_t *data)
+{
+ struct bt_ad_pattern *pattern;
+
+ if (!data || !len || offset >= BT_AD_MAX_DATA_LEN ||
+ len > BT_AD_MAX_DATA_LEN || offset + len > BT_AD_MAX_DATA_LEN) {
+ return NULL;
+ }
+
+ if (!ad_is_type_valid(type))
+ return NULL;
+
+ pattern = new0(struct bt_ad_pattern, 1);
+ if (!pattern)
+ return NULL;
+
+ pattern->len = len;
+ pattern->type = type;
+ pattern->offset = offset;
+ memcpy(pattern->data, data, len);
+
+ return pattern;
+}
+
+static void pattern_ad_data_match(void *data, void *user_data)
+{
+ struct bt_ad_data *ad_data = data;
+ struct pattern_match_info *info = user_data;
+ struct bt_ad_pattern *pattern;
+
+ if (!ad_data || !info)
+ return;
+
+ if (info->matched_pattern)
+ return;
+
+ pattern = info->current_pattern;
+
+ if (!pattern || ad_data->type != pattern->type)
+ return;
+
+ if (ad_data->len < pattern->offset + pattern->len)
+ return;
+
+ if (!memcmp(ad_data->data + pattern->offset, pattern->data,
+ pattern->len)) {
+ info->matched_pattern = pattern;
+ }
+}
+
+static void pattern_match(void *data, void *user_data)
+{
+ struct bt_ad_pattern *pattern = data;
+ struct pattern_match_info *info = user_data;
+
+ if (!pattern || !info)
+ return;
+
+ if (info->matched_pattern)
+ return;
+
+ info->current_pattern = pattern;
+
+ bt_ad_foreach_data(info->ad, pattern_ad_data_match, info);
+}
+
+struct bt_ad_pattern *bt_ad_pattern_match(struct bt_ad *ad,
+ struct queue *patterns)
+{
+ struct pattern_match_info info;
+
+ if (!ad || queue_isempty(patterns))
+ return NULL;
+
+ info.ad = ad;
+ info.matched_pattern = NULL;
+ info.current_pattern = NULL;
+
+ queue_foreach(patterns, pattern_match, &info);
+
+ return info.matched_pattern;
+}
diff --git a/src/shared/ad.h b/src/shared/ad.h
index 83eacab66..13adcb406 100644
--- a/src/shared/ad.h
+++ b/src/shared/ad.h
@@ -68,6 +68,7 @@
typedef void (*bt_ad_func_t)(void *data, void *user_data);
struct bt_ad;
+struct queue;
struct bt_ad_manufacturer_data {
uint16_t manufacturer_id;
@@ -87,8 +88,17 @@ struct bt_ad_data {
size_t len;
};
+struct bt_ad_pattern {
+ uint8_t type;
+ uint8_t offset;
+ uint8_t len;
+ uint8_t data[BT_AD_MAX_DATA_LEN];
+};
+
struct bt_ad *bt_ad_new(void);
+struct bt_ad *bt_ad_new_with_data(size_t len, const uint8_t *data);
+
struct bt_ad *bt_ad_ref(struct bt_ad *ad);
void bt_ad_unref(struct bt_ad *ad);
@@ -156,3 +166,9 @@ void bt_ad_foreach_data(struct bt_ad *ad, bt_ad_func_t func, void *user_data);
bool bt_ad_remove_data(struct bt_ad *ad, uint8_t type);
void bt_ad_clear_data(struct bt_ad *ad);
+
+struct bt_ad_pattern *bt_ad_pattern_new(uint8_t type, size_t offset,
+ size_t len, const uint8_t *data);
+
+struct bt_ad_pattern *bt_ad_pattern_match(struct bt_ad *ad,
+ struct queue *patterns);
--
2.26.2
