# determine as much as possible about the performance of that connection.
# (Specifically designed for measuring performance of fetches to Amazon S3.)
-import impacket, pcapy, re, sys
+import impacket, json, pcapy, re, sys
import impacket.ImpactDecoder, impacket.ImpactPacket
# Estimate of the network RTT
-RTT_EST = 0.03
+RTT_EST = 0.03 * 1e6
+
+def dump_data(obj):
+ return json.dumps(result_list, sort_keys=True, indent=2)
class Packet:
def __init__(self, connection, ts, pkt):
if self.start_time is None:
self.start_time = ts
ts -= self.start_time
- pkt = Packet(self, ts * 1e-6, self.decoder.decode(data))
+ pkt = Packet(self, ts, self.decoder.decode(data))
self.packets.append(pkt)
def split_trace(packets, predicate, before=True):
if len(segment) > 0:
yield segment
-def analyze_get(packets):
+def analyze_get(packets, prev_time = None):
packets = iter(packets)
-
- # First packet is the GET request itself
p = packets.next()
- if not(p.direction > 0 and p.data.startswith('GET')):
- print "Doesn't seem to be a GET request..."
- return
start_ts = p.ts
id_out = p.id
+ # Check for connection establishment (SYN/SYN-ACK) and use that to estimate
+ # th network RTT.
+ if p.tcp.get_SYN():
+ addr = p.ip.get_ip_dst()
+ p = packets.next()
+ #print "Connection establishment: RTT is", p.ts - start_ts
+ return {'syn_rtt': (p.ts - start_ts) / 1e6, 'addr': addr}
+
+ # Otherwise, we expect the first packet to be the GET request itself
+ if not(p.direction > 0 and p.data.startswith('GET')):
+ #print "Doesn't seem to be a GET request..."
+ return
+
# Find the first response packet containing data
while not(p.direction < 0 and p.datalen > 0):
p = packets.next()
resp_ts = p.ts
id_in = p.id
start_seq = p.seq[0]
+ tot_bytes = (p.seq[1] - start_seq) & 0xffffffff
+ spacings = []
- print "Response time:", resp_ts - start_ts
+ #print "Response time:", resp_ts - start_ts
# Scan through the incoming packets, looking for gaps in either the IP ID
# field or in the timing
last_ts = resp_ts
+ last_was_short = False
for p in packets:
gap = False
+ flags = []
+ bytenr = (p.seq[1] - start_seq) & 0xffffffff
if not p.direction < 0: continue
+ if p.tcp.get_FIN(): continue
+
+ if last_was_short:
+ flags.append('LAST_PACKET_SHORT')
+ last_was_short = False
if p.id != (id_in + 1) & 0xffff:
gap = True
- print "Sequence number gap at", id_in
- if p.ts - last_ts > 2 * RTT_EST:
- gap = True
- print "Long gap of", p.ts - last_ts
- elif p.ts - last_ts > RTT_EST / 2:
- gap = True
- print "Short gap of", p.ts - last_ts
- if gap:
- print " [occurred after", p.seq[0] - start_seq, "bytes, time", p.ts, "sec]"
- if p.datalen < 1460:
- print "Short packet of", p.datalen, "bytes, brings total to", p.seq[1] - start_seq
+ flags.append('IPID_GAP')
+ if p.datalen not in (1448, 1460):
+ last_was_short = True
+ if (p.seq[0] - start_seq) & 0xffffffff != tot_bytes:
+ flags.append('OUT_OF_ORDER')
+ if ((p.seq[0] - start_seq) & 0xffffffff) % 9000 == 0:
+ flags.append('9000')
+ spacings.append(((p.ts - last_ts) / 1e6, bytenr) + tuple(flags))
last_ts = p.ts
id_in = p.id
+ tot_bytes = max(tot_bytes, bytenr)
+
+ #print "Transferred %d bytes in %s seconds, initial response after %s" % (tot_bytes, last_ts - start_ts, resp_ts - start_ts)
+ if prev_time is not None:
+ prev_delay = start_ts - prev_time
+ else:
+ prev_delay = 0
+ return {'bytes': tot_bytes,
+ 'start_latency': resp_ts - start_ts,
+ 'finish_latency': last_ts - start_ts,
+ 'interpacket_times': spacings,
+ 'delay_from_previous': prev_delay}
if __name__ == '__main__':
for f in sys.argv[1:]:
conn = TcpAnalysis()
conn.process_file(f)
- ts = 0.0
+ ts = 0
def request_start(p):
return p.direction > 0 and p.datalen > 0
+ result_list = []
+ prev_time = None
for s in split_trace(conn.packets, request_start):
s = list(s)
if False:
for p in s:
- if p.ts - ts > 0.01:
- print "----"
- if p.ts - ts > 2 * RTT_EST:
- print "LONG DELAY\n----"
+ #if p.ts - ts > 0.01:
+ #print "----"
+ #if p.ts - ts > 2 * RTT_EST:
+ #print "LONG DELAY\n----"
ts = p.ts
- print p
- if p.direction > 0 and p.datalen > 0:
- print "Request:", repr(p.data)
- analyze_get(s)
- print "===="
+ #print p
+ #if p.direction > 0 and p.datalen > 0:
+ #print "Request:", repr(p.data)
+ results = analyze_get(s, prev_time)
+ if results is not None:
+ result_list.append(results)
+ prev_time = s[-1].ts
+ #print "===="
+
+ print dump_data(result_list)
projects / bluesky.git / blobdiff