Merge pull request #434 from google/gbg/show-timestamps

show timestamps from snoop logs

3 files changed, 83 insertions, 21 deletions

diff --git a/apps/show.py b/apps/show.py
index f849e3a..97640a3 100644
--- a/apps/show.py
+++ b/apps/show.py
@@ -15,7 +15,11 @@
 # -----------------------------------------------------------------------------
 # Imports
 # -----------------------------------------------------------------------------
+import datetime
+import logging
+import os
 import struct
+
 import click
 
 from bumble.colors import color
@@ -25,6 +29,14 @@ from bumble.helpers import PacketTracer
 
 
 # -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Classes
+# -----------------------------------------------------------------------------
 class SnoopPacketReader:
     '''
     Reader that reads HCI packets from a "snoop" file (based on RFC 1761, but not
@@ -36,12 +48,18 @@ class SnoopPacketReader:
     DATALINK_BSCP = 1003
     DATALINK_H5 = 1004
 
+    IDENTIFICATION_PATTERN = b'btsnoop\0'
+    TIMESTAMP_ANCHOR = datetime.datetime(2000, 1, 1)
+    TIMESTAMP_DELTA = 0x00E03AB44A676000
+    ONE_MICROSECOND = datetime.timedelta(microseconds=1)
+
     def __init__(self, source):
         self.source = source
+        self.at_end = False
 
         # Read the header
         identification_pattern = source.read(8)
-        if identification_pattern.hex().lower() != '6274736e6f6f7000':
+        if identification_pattern != self.IDENTIFICATION_PATTERN:
             raise ValueError(
                 'not a valid snoop file, unexpected identification pattern'
             )
@@ -55,19 +73,32 @@ class SnoopPacketReader:
         # Read the record header
         header = self.source.read(24)
         if len(header) < 24:
-            return (0, None)
+            self.at_end = True
+            return (None, 0, None)
+
+        # Parse the header
         (
             original_length,
             included_length,
             packet_flags,
             _cumulative_drops,
-            _timestamp_seconds,
-            _timestamp_microsecond,
-        ) = struct.unpack('>IIIIII', header)
+            timestamp,
+        ) = struct.unpack('>IIIIQ', header)
 
-        # Abort on truncated packets
+        # Skip truncated packets
         if original_length != included_length:
-            return (0, None)
+            print(
+                color(
+                    f"!!! truncated packet ({included_length}/{original_length})", "red"
+                )
+            )
+            self.source.read(included_length)
+            return (None, 0, None)
+
+        # Convert the timestamp to a datetime object.
+        ts_dt = self.TIMESTAMP_ANCHOR + datetime.timedelta(
+            microseconds=timestamp - self.TIMESTAMP_DELTA
+        )
 
         if self.data_link_type == self.DATALINK_H1:
             # The packet is un-encapsulated, look at the flags to figure out its type
@@ -89,7 +120,17 @@ class SnoopPacketReader:
                 bytes([packet_type]) + self.source.read(included_length),
             )
 
-        return (packet_flags & 1, self.source.read(included_length))
+        return (ts_dt, packet_flags & 1, self.source.read(included_length))
+
+
+# -----------------------------------------------------------------------------
+class Printer:
+    def __init__(self):
+        self.index = 0
+
+    def print(self, message: str) -> None:
+        self.index += 1
+        print(f"[{self.index:8}]{message}")
 
 
 # -----------------------------------------------------------------------------
@@ -122,24 +163,28 @@ def main(format, vendors, filename):
         packet_reader = PacketReader(input)
 
         def read_next_packet():
-            return (0, packet_reader.next_packet())
+            return (None, 0, packet_reader.next_packet())
 
     else:
         packet_reader = SnoopPacketReader(input)
         read_next_packet = packet_reader.next_packet
 
-    tracer = PacketTracer(emit_message=print)
+    printer = Printer()
+    tracer = PacketTracer(emit_message=printer.print)
 
-    while True:
+    while not packet_reader.at_end:
         try:
-            (direction, packet) = read_next_packet()
-            if packet is None:
-                break
-            tracer.trace(hci.HCI_Packet.from_bytes(packet), direction)
+            (timestamp, direction, packet) = read_next_packet()
+            if packet:
+                tracer.trace(hci.HCI_Packet.from_bytes(packet), direction, timestamp)
+            else:
+                printer.print(color("[TRUNCATED]", "red"))
         except Exception as error:
+            logger.exception()
             print(color(f'!!! {error}', 'red'))
 
 
 # -----------------------------------------------------------------------------
 if __name__ == '__main__':
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
     main()  # pylint: disable=no-value-for-parameter
diff --git a/bumble/helpers.py b/bumble/helpers.py
index c6a6d2e..80a376e 100644
--- a/bumble/helpers.py
+++ b/bumble/helpers.py
@@ -18,6 +18,7 @@
 from __future__ import annotations
 
 from collections.abc import Callable, MutableMapping
+import datetime
 from typing import cast, Any, Optional
 import logging
 
@@ -66,12 +67,13 @@ PSM_NAMES = {
     rfcomm.RFCOMM_PSM: 'RFCOMM',
     sdp.SDP_PSM: 'SDP',
     avdtp.AVDTP_PSM: 'AVDTP',
-    avctp.AVCTP_PSM: 'AVCTP'
+    avctp.AVCTP_PSM: 'AVCTP',
     # TODO: add more PSM values
 }
 
 AVCTP_PID_NAMES = {avrcp.AVRCP_PID: 'AVRCP'}
 
+
 # -----------------------------------------------------------------------------
 class PacketTracer:
     class AclStream:
@@ -207,6 +209,7 @@ class PacketTracer:
             self.label = label
             self.emit_message = emit_message
             self.acl_streams = {}  # ACL streams, by connection handle
+            self.packet_timestamp: Optional[datetime.datetime] = None
 
         def start_acl_stream(self, connection_handle: int) -> PacketTracer.AclStream:
             logger.info(
@@ -234,7 +237,10 @@ class PacketTracer:
                 # Let the other forwarder know so it can cleanup its stream as well
                 self.peer.end_acl_stream(connection_handle)
 
-        def on_packet(self, packet: HCI_Packet) -> None:
+        def on_packet(
+            self, timestamp: Optional[datetime.datetime], packet: HCI_Packet
+        ) -> None:
+            self.packet_timestamp = timestamp
             self.emit(packet)
 
             if packet.hci_packet_type == HCI_ACL_DATA_PACKET:
@@ -254,13 +260,22 @@ class PacketTracer:
                     )
 
         def emit(self, message: Any) -> None:
-            self.emit_message(f'[{self.label}] {message}')
+            if self.packet_timestamp:
+                prefix = f"[{self.packet_timestamp.strftime('%Y-%m-%d %H:%M:%S.%f')}]"
+            else:
+                prefix = ""
+            self.emit_message(f'{prefix}[{self.label}] {message}')
 
-    def trace(self, packet: HCI_Packet, direction: int = 0) -> None:
+    def trace(
+        self,
+        packet: HCI_Packet,
+        direction: int = 0,
+        timestamp: Optional[datetime.datetime] = None,
+    ) -> None:
         if direction == 0:
-            self.host_to_controller_analyzer.on_packet(packet)
+            self.host_to_controller_analyzer.on_packet(timestamp, packet)
         else:
-            self.controller_to_host_analyzer.on_packet(packet)
+            self.controller_to_host_analyzer.on_packet(timestamp, packet)
 
     def __init__(
         self,
diff --git a/bumble/transport/common.py b/bumble/transport/common.py
index f767f54..ef35c9f 100644
--- a/bumble/transport/common.py
+++ b/bumble/transport/common.py
@@ -168,11 +168,13 @@ class PacketReader:
 
     def __init__(self, source: io.BufferedReader) -> None:
         self.source = source
+        self.at_end = False
 
     def next_packet(self) -> Optional[bytes]:
         # Get the packet type
         packet_type = self.source.read(1)
         if len(packet_type) != 1:
+            self.at_end = True
             return None
 
         # Get the packet info based on its type