1# Monitor the system for dropped packets and proudce a report of drop locations and counts
2# SPDX-License-Identifier: GPL-2.0
3
4import os
5import sys
6
7sys.path.append(os.environ['PERF_EXEC_PATH'] + \
8		'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
9
10from perf_trace_context import *
11from Core import *
12from Util import *
13
14drop_log = {}
15kallsyms = []
16
17def get_kallsyms_table():
18	global kallsyms
19
20	try:
21		f = open("/proc/kallsyms", "r")
22	except:
23		return
24
25	for line in f:
26		loc = int(line.split()[0], 16)
27		name = line.split()[2]
28		kallsyms.append((loc, name))
29	kallsyms.sort()
30
31def get_sym(sloc):
32	loc = int(sloc)
33
34	# Invariant: kallsyms[i][0] <= loc for all 0 <= i <= start
35	#            kallsyms[i][0] > loc for all end <= i < len(kallsyms)
36	start, end = -1, len(kallsyms)
37	while end != start + 1:
38		pivot = (start + end) // 2
39		if loc < kallsyms[pivot][0]:
40			end = pivot
41		else:
42			start = pivot
43
44	# Now (start == -1 or kallsyms[start][0] <= loc)
45	# and (start == len(kallsyms) - 1 or loc < kallsyms[start + 1][0])
46	if start >= 0:
47		symloc, name = kallsyms[start]
48		return (name, loc - symloc)
49	else:
50		return (None, 0)
51
52def print_drop_table():
53	print "%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT")
54	for i in drop_log.keys():
55		(sym, off) = get_sym(i)
56		if sym == None:
57			sym = i
58		print "%25s %25s %25s" % (sym, off, drop_log[i])
59
60
61def trace_begin():
62	print "Starting trace (Ctrl-C to dump results)"
63
64def trace_end():
65	print "Gathering kallsyms data"
66	get_kallsyms_table()
67	print_drop_table()
68
69# called from perf, when it finds a correspoinding event
70def skb__kfree_skb(name, context, cpu, sec, nsec, pid, comm, callchain,
71		   skbaddr, location, protocol):
72	slocation = str(location)
73	try:
74		drop_log[slocation] = drop_log[slocation] + 1
75	except:
76		drop_log[slocation] = 1
77