Review at https://gerrit.osmocom.org/6837
fake_trx/data_dump.py: use 2 bytes to store message length One byte may store a value in range [0x00, 0xff]. The maximal 0xff value is 255 in dec, so a message length is limited to 255 bytes. This is enough for GSM bursts, but not for EDGE. Since this change, two bytes of header are used to store the pending message length. All captures created before are not supported anymore... Change-Id: I5a69d5cf2914fe56b2f9acca6054c9470627f91e --- M src/target/fake_trx/data_dump.py 1 file changed, 7 insertions(+), 4 deletions(-) git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/37/6837/1 diff --git a/src/target/fake_trx/data_dump.py b/src/target/fake_trx/data_dump.py index b904736..56e314c 100644 --- a/src/target/fake_trx/data_dump.py +++ b/src/target/fake_trx/data_dump.py @@ -30,7 +30,7 @@ # Constants TAG_L12TRX = '\x01' TAG_TRX2L1 = '\x02' - HDR_LENGTH = 2 + HDR_LENGTH = 3 # Generates raw bytes from a DATA message # Return value: raw message bytes @@ -46,15 +46,18 @@ # Generate a message payload msg_raw = msg.gen_msg() - # Calculate the length + # Calculate and pack the message length msg_len = len(msg_raw) + # Pack to unsigned short (2 bytes, BE) + msg_len = struct.pack(">H", msg_len) + # Concatenate a message with header - return bytearray([tag, msg_len]) + msg_raw + return bytearray(tag + msg_len) + msg_raw def parse_hdr(self, hdr): # Extract the header info - msg_len = struct.unpack("<B", hdr[1])[0] + msg_len = struct.unpack(">H", hdr[1:3])[0] tag = hdr[0] # Check if tag is known -- To view, visit https://gerrit.osmocom.org/6837 To unsubscribe, visit https://gerrit.osmocom.org/settings Gerrit-MessageType: newchange Gerrit-Change-Id: I5a69d5cf2914fe56b2f9acca6054c9470627f91e Gerrit-PatchSet: 1 Gerrit-Project: osmocom-bb Gerrit-Branch: master Gerrit-Owner: Harald Welte <lafo...@gnumonks.org>