1# Monitor the system for dropped packets and proudce a report of drop locations and counts
2# SPDX-License-Identifier: GPL-2.0
3
4from __future__ import print_function
5
6import os
7import sys
8
9sys.path.append(os.environ['PERF_EXEC_PATH'] + \
10	'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')
11
12from perf_trace_context import *
13from Core import *
14from Util import *
15
16drop_log = {}
17kallsyms = []
18
19def get_kallsyms_table():
20	global kallsyms
21
22	try:
23		f = open("/proc/kallsyms", "r")
24	except:
25		return
26
27	for line in f:
28		loc = int(line.split()[0], 16)
29		name = line.split()[2]
30		kallsyms.append((loc, name))
31	kallsyms.sort()
32
33def get_sym(sloc):
34	loc = int(sloc)
35
36	# Invariant: kallsyms[i][0] <= loc for all 0 <= i <= start
37	#            kallsyms[i][0] > loc for all end <= i < len(kallsyms)
38	start, end = -1, len(kallsyms)
39	while end != start + 1:
40		pivot = (start + end) // 2
41		if loc < kallsyms[pivot][0]:
42			end = pivot
43		else:
44			start = pivot
45
46	# Now (start == -1 or kallsyms[start][0] <= loc)
47	# and (start == len(kallsyms) - 1 or loc < kallsyms[start + 1][0])
48	if start >= 0:
49		symloc, name = kallsyms[start]
50		return (name, loc - symloc)
51	else:
52		return (None, 0)
53
54def print_drop_table():
55	print("%25s %25s %25s" % ("LOCATION", "OFFSET", "COUNT"))
56	for i in drop_log.keys():
57		(sym, off) = get_sym(i)
58		if sym == None:
59			sym = i
60		print("%25s %25s %25s" % (sym, off, drop_log[i]))
61
62
63def trace_begin():
64	print("Starting trace (Ctrl-C to dump results)")
65
66def trace_end():
67	print("Gathering kallsyms data")
68	get_kallsyms_table()
69	print_drop_table()
70
71# called from perf, when it finds a corresponding event
72def skb__kfree_skb(name, context, cpu, sec, nsec, pid, comm, callchain,
73		   skbaddr, location, protocol, reason):
74	slocation = str(location)
75	try:
76		drop_log[slocation] = drop_log[slocation] + 1
77	except:
78		drop_log[slocation] = 1
79