blob: 7d2db890c5c82d8847ad9efce6ceacc6077b0cd2 [file] [log] [blame]
#!/usr/bin/python
#
# strlen_count Trace strlen() and print a frequency count of strings.
# For Linux, uses BCC, eBPF. Embedded C.
#
# Written as a basic example of BCC and uprobes.
#
# Also see strlensnoop.
#
# Copyright 2016 Netflix, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
from __future__ import print_function
from bcc import BPF
from time import sleep
# load BPF program
b = BPF(text="""
#include <uapi/linux/ptrace.h>
struct key_t {
char c[80];
};
BPF_HASH(counts, struct key_t);
int count(struct pt_regs *ctx) {
if (!PT_REGS_PARM1(ctx))
return 0;
struct key_t key = {};
u64 zero = 0, *val;
bpf_probe_read(&key.c, sizeof(key.c), (void *)PT_REGS_PARM1(ctx));
val = counts.lookup_or_init(&key, &zero);
(*val)++;
return 0;
};
""")
b.attach_uprobe(name="c", sym="strlen", fn_name="count")
# header
print("Tracing strlen()... Hit Ctrl-C to end.")
# sleep until Ctrl-C
try:
sleep(99999999)
except KeyboardInterrupt:
pass
# print output
print("%10s %s" % ("COUNT", "STRING"))
counts = b.get_table("counts")
for k, v in sorted(counts.items(), key=lambda counts: counts[1].value):
print("%10d \"%s\"" % (v.value, k.c.encode('string-escape')))