Extending the function gatt_write_char for support GATT Write Long
Characteristics. MTU is checked and if the payload does not fit,
the prepare and execute write are used to do the transaction.
---
attrib/att.h | 4 ++
attrib/gatt.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++---
attrib/gatttool.c | 2 +-
attrib/interactive.c | 2 +-
4 files changed, 110 insertions(+), 7 deletions(-)
diff --git a/attrib/att.h b/attrib/att.h
index 64d22ca..e7a29cb 100644
--- a/attrib/att.h
+++ b/attrib/att.h
@@ -92,6 +92,10 @@
#define ATT_CID 4
#define ATT_PSM 31
+/* Flags for Execute Write Request Operation */
+#define ATT_CANCEL_ALL_PREP_WRITES 0x00
+#define ATT_WRITE_ALL_PREP_WRITES 0x01
+
struct att_data_list {
uint16_t num;
uint16_t len;
diff --git a/attrib/gatt.c b/attrib/gatt.c
index 6f9a11d..b7eb736 100644
--- a/attrib/gatt.c
+++ b/attrib/gatt.c
@@ -520,21 +520,120 @@ guint gatt_read_char(GAttrib *attrib, uint16_t handle, uint16_t offset,
return id;
}
+struct write_long_data {
+ GAttrib *attrib;
+ GAttribResultFunc func;
+ gpointer user_data;
+ guint16 handle;
+ uint16_t offset;
+ uint8_t *value;
+ int vlen;
+};
+
+static guint execute_write(GAttrib *attrib, uint8_t flags,
+ GAttribResultFunc func, gpointer user_data)
+{
+ uint8_t *buf;
+ int buflen;
+ guint16 plen;
+
+ buf = g_attrib_get_buffer(attrib, &buflen);
+ plen = enc_exec_write_req(flags, buf, buflen);
+ if (plen == 0)
+ return 0;
+
+ return g_attrib_send(attrib, 0, buf[0], buf, plen, func, user_data,
+ NULL);
+}
+
+static guint prepare_write(GAttrib *attrib, uint16_t handle, uint16_t offset,
+ uint8_t *value, int vlen, GAttribResultFunc func,
+ gpointer user_data);
+
+static void prepare_write_cb(guint8 status, const guint8 *rpdu,
+ guint16 rlen, gpointer user_data)
+{
+ struct write_long_data *long_write = user_data;
+
+ if (status != 0) {
+ long_write->func(status, rpdu, rlen, long_write->user_data);
+ return;
+ }
+
+ /* Skip Prepare Write Response PDU header (5 bytes) */
+ long_write->offset += rlen - 5;
+
+ if (long_write->offset == long_write->vlen){
+ execute_write(long_write->attrib, ATT_WRITE_ALL_PREP_WRITES,
+ long_write->func, long_write->user_data);
+ g_free(long_write->value);
+ g_free(long_write);
+
+ return;
+ }
+
+ prepare_write(long_write->attrib, long_write->handle,
+ long_write->offset, long_write->value, long_write->vlen,
+ long_write->func, long_write);
+}
+
+static guint prepare_write(GAttrib *attrib, uint16_t handle, uint16_t offset,
+ uint8_t *value, int vlen, GAttribResultFunc func,
+ gpointer user_data)
+{
+ guint16 plen;
+ int buflen;
+ uint8_t *buf;
+
+ buf = g_attrib_get_buffer(attrib, &buflen);
+
+ plen = enc_prep_write_req(handle, offset, &value[offset], vlen - offset,
+ buf, buflen);
+ if (plen == 0)
+ return 0;
+
+ return g_attrib_send(attrib, 0, buf[0], buf, plen, prepare_write_cb,
+ user_data, NULL);
+}
+
guint gatt_write_char(GAttrib *attrib, uint16_t handle, uint8_t *value,
int vlen, GAttribResultFunc func, gpointer user_data)
{
uint8_t *buf;
int buflen;
guint16 plen;
+ struct write_long_data *long_write;
buf = g_attrib_get_buffer(attrib, &buflen);
- if (func)
- plen = enc_write_req(handle, value, vlen, buf, buflen);
- else
- plen = enc_write_cmd(handle, value, vlen, buf, buflen);
- return g_attrib_send(attrib, 0, buf[0], buf, plen, func,
+ /* Only use Write Request/Command if payload fits on a single transfer,
+ * including 3 bytes for the header. */
+ if (vlen <= buflen - 3) {
+ if (func)
+ plen = enc_write_req(handle, value, vlen, buf,
+ buflen);
+ else
+ plen = enc_write_cmd(handle, value, vlen, buf,
+ buflen);
+
+ return g_attrib_send(attrib, 0, buf[0], buf, plen, func,
user_data, NULL);
+ }
+
+ /* Write Long Characteristic Values */
+ long_write = g_try_new0(struct write_long_data, 1);
+ if (long_write == NULL)
+ return 0;
+
+ long_write->attrib = attrib;
+ long_write->func = func;
+ long_write->user_data = user_data;
+ long_write->handle = handle;
+ long_write->value = g_memdup(value,vlen);
+ long_write->vlen = vlen;
+
+ return prepare_write(attrib, handle, long_write->offset, value, vlen,
+ func, long_write);
}
guint gatt_exchange_mtu(GAttrib *attrib, uint16_t mtu, GAttribResultFunc func,
diff --git a/attrib/gatttool.c b/attrib/gatttool.c
index 1f23522..a11ca9f 100644
--- a/attrib/gatttool.c
+++ b/attrib/gatttool.c
@@ -371,7 +371,7 @@ static void char_write_req_cb(guint8 status, const guint8 *pdu, guint16 plen,
goto done;
}
- if (!dec_write_resp(pdu, plen)) {
+ if (!dec_write_resp(pdu, plen) && !dec_exec_write_resp(pdu, plen)) {
g_printerr("Protocol error\n");
goto done;
}
diff --git a/attrib/interactive.c b/attrib/interactive.c
index 3657798..6cd8bd5 100644
--- a/attrib/interactive.c
+++ b/attrib/interactive.c
@@ -588,7 +588,7 @@ static void char_write_req_cb(guint8 status, const guint8 *pdu, guint16 plen,
return;
}
- if (!dec_write_resp(pdu, plen)) {
+ if (!dec_write_resp(pdu, plen) && !dec_exec_write_resp(pdu, plen)) {
printf("Protocol error\n");
return;
}
--
1.7.9.5
--
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