2022-01-27 19:23:31 -08:00

372 lines
14 KiB
Python

##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2015 Stefan Brüns <stefan.bruens@rwth-aachen.de>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
import struct
class SamplerateError(Exception):
pass
class pcap_usb_pkt():
# Linux usbmon format, see Documentation/usb/usbmon.txt
h = b'\x00\x00\x00\x00' # ID part 1
h += b'\x00\x00\x00\x00' # ID part 2
h += b'C' # 'S'ubmit / 'C'omplete / 'E'rror
h += b'\x03' # ISO (0), Intr, Control, Bulk (3)
h += b'\x00' # Endpoint
h += b'\x00' # Device address
h += b'\x00\x00' # Bus number
h += b'-' # Setup tag - 0: Setup present, '-' otherwise
h += b'<' # Data tag - '<' no data, 0 otherwise
# Timestamp
h += b'\x00\x00\x00\x00' # TS seconds part 1
h += b'\x00\x00\x00\x00' # TS seconds part 2
h += b'\x00\x00\x00\x00' # TS useconds
#
h += b'\x00\x00\x00\x00' # Status 0: OK
h += b'\x00\x00\x00\x00' # URB length
h += b'\x00\x00\x00\x00' # Data length
# Setup packet data, valid if setup tag == 0
h += b'\x00' # bmRequestType
h += b'\x00' # bRequest
h += b'\x00\x00' # wValue
h += b'\x00\x00' # wIndex
h += b'\x00\x00' # wLength
#
h += b'\x00\x00\x00\x00' # ISO/interrupt interval
h += b'\x00\x00\x00\x00' # ISO start frame
h += b'\x00\x00\x00\x00' # URB flags
h += b'\x00\x00\x00\x00' # Number of ISO descriptors
def __init__(self, req, ts, is_submit):
self.header = bytearray(pcap_usb_pkt.h)
self.data = b''
self.set_urbid(req['id'])
self.set_urbtype('S' if is_submit else 'C')
self.set_timestamp(ts)
self.set_addr_ep(req['addr'], req['ep'])
if req['type'] in ('SETUP IN', 'SETUP OUT'):
self.set_transfertype(2) # Control
self.set_setup(req['setup_data'])
if req['type'] in ('BULK IN'):
self.set_addr_ep(req['addr'], 0x80 | req['ep'])
self.set_data(req['data'])
def set_urbid(self, urbid):
self.header[4:8] = struct.pack('>I', urbid)
def set_urbtype(self, urbtype):
self.header[8] = ord(urbtype)
def set_transfertype(self, transfertype):
self.header[9] = transfertype
def set_addr_ep(self, addr, ep):
self.header[11] = addr
self.header[10] = ep
def set_timestamp(self, ts):
self.timestamp = ts
self.header[20:24] = struct.pack('>I', ts[0]) # seconds
self.header[24:28] = struct.pack('>I', ts[1]) # microseconds
def set_data(self, data):
self.data = data
self.header[15] = 0
self.header[36:40] = struct.pack('>I', len(data))
def set_setup(self, data):
self.header[14] = 0
self.header[40:48] = data
def packet(self):
return bytes(self.header) + bytes(self.data)
def record_header(self):
# See https://wiki.wireshark.org/Development/LibpcapFileFormat.
(secs, usecs) = self.timestamp
h = struct.pack('>I', secs) # TS seconds
h += struct.pack('>I', usecs) # TS microseconds
# No truncation, so both lengths are the same.
h += struct.pack('>I', len(self)) # Captured len (usb hdr + data)
h += struct.pack('>I', len(self)) # Original len
return h
def __len__(self):
return 64 + len(self.data)
class Decoder(srd.Decoder):
api_version = 3
id = 'usb_request'
name = 'USB request'
longname = 'Universal Serial Bus (LS/FS) transaction/request'
desc = 'USB (low-speed/full-speed) transaction/request protocol.'
license = 'gplv2+'
inputs = ['usb_packet']
outputs = ['usb_request']
tags = ['PC']
annotations = (
('request-setup-read', 'Setup: Device-to-host'),
('request-setup-write', 'Setup: Host-to-device'),
('request-bulk-read', 'Bulk: Device-to-host'),
('request-bulk-write', 'Bulk: Host-to-device'),
('errors', 'Unexpected packets'),
)
annotation_rows = (
('request', 'USB requests', tuple(range(4))),
('errors', 'Errors', (4,)),
)
binary = (
('pcap', 'PCAP format'),
)
def __init__(self):
self.reset()
def reset(self):
self.samplerate = None
self.request = {}
self.request_id = 0
self.transaction_state = 'IDLE'
self.ss_transaction = None
self.es_transaction = None
self.transaction_ep = None
self.transaction_addr = None
self.wrote_pcap_header = False
def putr(self, ss, es, data):
self.put(ss, es, self.out_ann, data)
def putb(self, ts, data):
self.put(ts, ts, self.out_binary, data)
def pcap_global_header(self):
# See https://wiki.wireshark.org/Development/LibpcapFileFormat.
h = b'\xa1\xb2\xc3\xd4' # Magic, indicate microsecond ts resolution
h += b'\x00\x02' # Major version 2
h += b'\x00\x04' # Minor version 4
h += b'\x00\x00\x00\x00' # Correction vs. UTC, seconds
h += b'\x00\x00\x00\x00' # Timestamp accuracy
h += b'\xff\xff\xff\xff' # Max packet len
# LINKTYPE_USB_LINUX_MMAPPED 220
# Linux usbmon format, see Documentation/usb/usbmon.txt.
h += b'\x00\x00\x00\xdc' # Link layer
return h
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
if self.samplerate:
self.secs_per_sample = float(1) / float(self.samplerate)
def start(self):
self.out_binary = self.register(srd.OUTPUT_BINARY)
self.out_ann = self.register(srd.OUTPUT_ANN)
def handle_transfer(self):
request_started = 0
request_end = self.handshake in ('ACK', 'STALL', 'timeout')
ep = self.transaction_ep
addr = self.transaction_addr
# Handle protocol STALLs, condition lasts until next SETUP transfer (8.5.3.4)
if self.transaction_type == 'SETUP' and (addr, ep) in self.request:
request = self.request[(addr,ep)]
if request['type'] in ('SETUP IN', 'SETUP OUT'):
request['es'] = self.ss_transaction
self.handle_request(0, 1)
if not (addr, ep) in self.request:
self.request[(addr, ep)] = {'setup_data': [], 'data': [],
'type': None, 'ss': self.ss_transaction, 'es': None,
'id': self.request_id, 'addr': addr, 'ep': ep}
self.request_id += 1
request_started = 1
request = self.request[(addr,ep)]
if request_end:
request['es'] = self.es_transaction
request['handshake'] = self.handshake
# BULK or INTERRUPT transfer
if request['type'] in (None, 'BULK IN') and self.transaction_type == 'IN':
request['type'] = 'BULK IN'
request['data'] += self.transaction_data
self.handle_request(request_started, request_end)
elif request['type'] in (None, 'BULK OUT') and self.transaction_type == 'OUT':
request['type'] = 'BULK OUT'
request['data'] += self.transaction_data
self.handle_request(request_started, request_end)
# CONTROL, SETUP stage
elif request['type'] is None and self.transaction_type == 'SETUP':
request['setup_data'] = self.transaction_data
request['wLength'] = struct.unpack('<H',
bytes(self.transaction_data[6:8]))[0]
if self.transaction_data[0] & 0x80:
request['type'] = 'SETUP IN'
self.handle_request(1, 0)
else:
request['type'] = 'SETUP OUT'
self.handle_request(request['wLength'] == 0, 0)
# CONTROL, DATA stage
elif request['type'] == 'SETUP IN' and self.transaction_type == 'IN':
request['data'] += self.transaction_data
elif request['type'] == 'SETUP OUT' and self.transaction_type == 'OUT':
request['data'] += self.transaction_data
if request['wLength'] == len(request['data']):
self.handle_request(1, 0)
# CONTROL, STATUS stage
elif request['type'] == 'SETUP IN' and self.transaction_type == 'OUT':
self.handle_request(0, request_end)
elif request['type'] == 'SETUP OUT' and self.transaction_type == 'IN':
self.handle_request(0, request_end)
else:
return
return
def ts_from_samplenum(self, sample):
ts = float(sample) * self.secs_per_sample
return (int(ts), int((ts % 1.0) * 1e6))
def write_pcap_header(self):
if not self.wrote_pcap_header:
self.put(0, 0, self.out_binary, [0, self.pcap_global_header()])
self.wrote_pcap_header = True
def request_summary(self, request):
s = '['
if request['type'] in ('SETUP IN', 'SETUP OUT'):
for b in request['setup_data']:
s += ' %02X' % b
s += ' ]['
for b in request['data']:
s += ' %02X' % b
s += ' ] : %s' % request['handshake']
return s
def handle_request(self, request_start, request_end):
if request_start != 1 and request_end != 1:
return
self.write_pcap_header()
ep = self.transaction_ep
addr = self.transaction_addr
request = self.request[(addr, ep)]
ss, es = request['ss'], request['es']
if request_start == 1:
# Issue PCAP 'SUBMIT' packet.
ts = self.ts_from_samplenum(ss)
pkt = pcap_usb_pkt(request, ts, True)
self.putb(ss, [0, pkt.record_header()])
self.putb(ss, [0, pkt.packet()])
if request_end == 1:
# Write annotation.
summary = self.request_summary(request)
if request['type'] == 'SETUP IN':
self.putr(ss, es, [0, ['SETUP in: %s' % summary]])
elif request['type'] == 'SETUP OUT':
self.putr(ss, es, [1, ['SETUP out: %s' % summary]])
elif request['type'] == 'BULK IN':
self.putr(ss, es, [2, ['BULK in: %s' % summary]])
elif request['type'] == 'BULK OUT':
self.putr(ss, es, [3, ['BULK out: %s' % summary]])
# Issue PCAP 'COMPLETE' packet.
ts = self.ts_from_samplenum(es)
pkt = pcap_usb_pkt(request, ts, False)
self.putb(ss, [0, pkt.record_header()])
self.putb(ss, [0, pkt.packet()])
del self.request[(addr, ep)]
def decode(self, ss, es, data):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
ptype, pdata = data
# We only care about certain packet types for now.
if ptype not in ('PACKET'):
return
pcategory, pname, pinfo = pdata
if pcategory == 'TOKEN':
if pname == 'SOF':
return
if self.transaction_state == 'TOKEN RECEIVED':
transaction_timeout = self.es_transaction
# Token length is 35 bits, timeout is 16..18 bit times
# (USB 2.0 7.1.19.1).
transaction_timeout += int((self.es_transaction - self.ss_transaction) / 2)
if ss > transaction_timeout:
self.es_transaction = transaction_timeout
self.handshake = 'timeout'
self.handle_transfer()
self.transaction_state = 'IDLE'
if self.transaction_state != 'IDLE':
self.putr(ss, es, [4, ['ERR: received %s token in state %s' %
(pname, self.transaction_state)]])
return
sync, pid, addr, ep, crc5 = pinfo
self.transaction_data = []
self.ss_transaction = ss
self.es_transaction = es
self.transaction_state = 'TOKEN RECEIVED'
self.transaction_ep = ep
self.transaction_addr = addr
self.transaction_type = pname # IN OUT SETUP
elif pcategory == 'DATA':
if self.transaction_state != 'TOKEN RECEIVED':
self.putr(ss, es, [4, ['ERR: received %s token in state %s' %
(pname, self.transaction_state)]])
return
self.transaction_data = pinfo[2]
self.transaction_state = 'DATA RECEIVED'
elif pcategory == 'HANDSHAKE':
if self.transaction_state not in ('TOKEN RECEIVED', 'DATA RECEIVED'):
self.putr(ss, es, [4, ['ERR: received %s token in state %s' %
(pname, self.transaction_state)]])
return
self.handshake = pname
self.transaction_state = 'IDLE'
self.es_transaction = es
self.handle_transfer()
elif pname == 'PRE':
return
else:
self.putr(ss, es, [4, ['ERR: received unhandled %s token in state %s' %
(pname, self.transaction_state)]])
return