#! /usr/bin/python3
#
# syscount   Summarize syscall counts and latencies.
#
# USAGE: syscount [-h] [-p PID] [-t TID] [-i INTERVAL] [-d DURATION] [-T TOP]
#                 [-x] [-e ERRNO] [-L] [-m] [-P] [-l] [--syscall SYSCALL]
#
# Copyright 2017, Sasha Goldshtein.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 15-Feb-2017   Sasha Goldshtein    Created this.
# 16-May-2022   Rocky Xing          Added TID filter support.
# 26-Jul-2022   Rocky Xing          Added syscall filter support.

from time import sleep, strftime
import argparse
import errno
import itertools
import sys
import signal
from bcc import BPF
from bcc.utils import printb
from bcc.syscall import syscall_name, syscalls

if sys.version_info.major < 3:
    izip_longest = itertools.izip_longest
else:
    izip_longest = itertools.zip_longest

# signal handler
def signal_ignore(signal, frame):
    print()

def handle_errno(errstr):
    try:
        return abs(int(errstr))
    except ValueError:
        pass

    try:
        return getattr(errno, errstr)
    except AttributeError:
        raise argparse.ArgumentTypeError("couldn't map %s to an errno" % errstr)


parser = argparse.ArgumentParser(
    description="Summarize syscall counts and latencies.")
parser.add_argument("-p", "--pid", type=int,
    help="trace only this pid")
parser.add_argument("-t", "--tid", type=int,
    help="trace only this tid")
parser.add_argument("-c", "--ppid", type=int,
    help="trace only child of this pid")
parser.add_argument("-i", "--interval", type=int,
    help="print summary at this interval (seconds)")
parser.add_argument("-d", "--duration", type=int,
    help="total duration of trace, in seconds")
parser.add_argument("-T", "--top", type=int, default=10,
    help="print only the top syscalls by count or latency")
parser.add_argument("-x", "--failures", action="store_true",
    help="trace only failed syscalls (return < 0)")
parser.add_argument("-e", "--errno", type=handle_errno,
    help="trace only syscalls that return this error (numeric or EPERM, etc.)")
parser.add_argument("-L", "--latency", action="store_true",
    help="collect syscall latency")
parser.add_argument("-m", "--milliseconds", action="store_true",
    help="display latency in milliseconds (default: microseconds)")
parser.add_argument("-P", "--process", action="store_true",
    help="count by process and not by syscall")
parser.add_argument("-l", "--list", action="store_true",
    help="print list of recognized syscalls and exit")
parser.add_argument("--syscall", type=str,
    help="trace this syscall only (use option -l to get all recognized syscalls)")
parser.add_argument("--ebpf", action="store_true",
    help=argparse.SUPPRESS)
args = parser.parse_args()
if args.duration and not args.interval:
    args.interval = args.duration
if not args.interval:
    args.interval = 99999999

syscall_nr = -1
if args.syscall is not None:
    syscall = bytes(args.syscall, 'utf-8')
    for key, value in syscalls.items():
        if syscall == value:
            syscall_nr = key
            break
    if syscall_nr == -1:
        print("Error: syscall '%s' not found. Exiting." % args.syscall)
        sys.exit(1)

if args.list:
    for grp in izip_longest(*(iter(sorted(syscalls.values())),) * 4):
        print("   ".join(["%-22s" % s.decode() for s in grp if s is not None]))
    sys.exit(0)

text = """
#include <linux/sched.h>

#ifdef LATENCY
struct data_t {
    u64 count;
    u64 total_ns;
};

BPF_HASH(start, u64, u64);
BPF_HASH(data, u32, struct data_t);
#else
BPF_HASH(data, u32, u64);
#endif

#ifdef LATENCY
TRACEPOINT_PROBE(raw_syscalls, sys_enter) {
    u64 pid_tgid = bpf_get_current_pid_tgid();
    u32 pid = pid_tgid >> 32;
    u32 tid = (u32)pid_tgid;

#ifdef FILTER_SYSCALL_NR
    if (args->id != FILTER_SYSCALL_NR)
        return 0;
#endif

#ifdef FILTER_PID
    if (pid != FILTER_PID)
        return 0;
#endif

#ifdef FILTER_TID
    if (tid != FILTER_TID)
        return 0;
#endif

#ifdef FILTER_PPID
    struct task_struct *task = (struct task_struct *)bpf_get_current_task();
    u32 ppid = task->real_parent->tgid;
    if (ppid != FILTER_PPID)
        return 0;
#endif

    u64 t = bpf_ktime_get_ns();
    start.update(&pid_tgid, &t);
    return 0;
}
#endif

TRACEPOINT_PROBE(raw_syscalls, sys_exit) {
    u64 pid_tgid = bpf_get_current_pid_tgid();
    u32 pid = pid_tgid >> 32;
    u32 tid = (u32)pid_tgid;

#ifdef FILTER_SYSCALL_NR
    if (args->id != FILTER_SYSCALL_NR)
        return 0;
#endif

#ifdef FILTER_PID
    if (pid != FILTER_PID)
        return 0;
#endif

#ifdef FILTER_TID
    if (tid != FILTER_TID)
        return 0;
#endif

#ifdef FILTER_PPID
    struct task_struct *task = (struct task_struct *)bpf_get_current_task();
    u32 ppid = task->real_parent->tgid;
    if (ppid != FILTER_PPID)
        return 0;
#endif

#ifdef FILTER_FAILED
    if (args->ret >= 0)
        return 0;
#endif

#ifdef FILTER_ERRNO
    if (args->ret != -FILTER_ERRNO)
        return 0;
#endif

#ifdef BY_PROCESS
    u32 key = pid_tgid >> 32;
#else
    u32 key = args->id;
#endif

#ifdef LATENCY
    struct data_t *val, zero = {};
    u64 *start_ns = start.lookup(&pid_tgid);
    if (!start_ns)
        return 0;

    val = data.lookup_or_try_init(&key, &zero);
    if (val) {
        lock_xadd(&val->count, 1);
        lock_xadd(&val->total_ns, bpf_ktime_get_ns() - *start_ns);
    }
#else
    u64 *val, zero = 0;
    val = data.lookup_or_try_init(&key, &zero);
    if (val) {
        lock_xadd(val, 1);
    }
#endif
    return 0;
}
"""

if args.pid:
    text = ("#define FILTER_PID %d\n" % args.pid) + text
elif args.tid:
    text = ("#define FILTER_TID %d\n" % args.tid) + text
elif args.ppid:
    text = ("#define FILTER_PPID %d\n" % args.ppid) + text
if args.failures:
    text = "#define FILTER_FAILED\n" + text
if args.errno:
    text = "#define FILTER_ERRNO %d\n" % abs(args.errno) + text
if args.latency:
    text = "#define LATENCY\n" + text
if args.process:
    text = "#define BY_PROCESS\n" + text
if args.syscall is not None:
    text = ("#define FILTER_SYSCALL_NR %d\n" % syscall_nr) + text
if args.ebpf:
    print(text)
    exit()

bpf = BPF(text=text)

def print_stats():
    if args.latency:
        print_latency_stats()
    else:
        print_count_stats()

agg_colname = "PID    COMM" if args.process else "SYSCALL"
time_colname = "TIME (ms)" if args.milliseconds else "TIME (us)"

def comm_for_pid(pid):
    try:
        return open("/proc/%d/comm" % pid, "rb").read().strip()
    except Exception:
        return b"[unknown]"

def agg_colval(key):
    if args.process:
        return b"%-6d %-15s" % (key.value, comm_for_pid(key.value))
    else:
        return syscall_name(key.value)

# check whether hash table batch ops is supported
htab_batch_ops = True if BPF.kernel_struct_has_field(b'bpf_map_ops',
        b'map_lookup_and_delete_batch') == 1 else False

def print_count_stats():
    data = bpf["data"]
    print("[%s]" % strftime("%H:%M:%S"))
    print("%-22s %8s" % (agg_colname, "COUNT"))
    for k, v in sorted(data.items_lookup_and_delete_batch()
                       if htab_batch_ops else data.items(),
                       key=lambda kv: -kv[1].value)[:args.top]:
        if k.value == 0xFFFFFFFF:
            continue    # happens occasionally, we don't need it
        printb(b"%-22s %8d" % (agg_colval(k), v.value))
    print("")
    if not htab_batch_ops:
        data.clear()

def print_latency_stats():
    data = bpf["data"]
    print("[%s]" % strftime("%H:%M:%S"))
    print("%-22s %8s %16s" % (agg_colname, "COUNT", time_colname))
    for k, v in sorted(data.items_lookup_and_delete_batch()
                       if htab_batch_ops else data.items(),
                       key=lambda kv: -kv[1].total_ns)[:args.top]:
        if k.value == 0xFFFFFFFF:
            continue    # happens occasionally, we don't need it
        printb((b"%-22s %8d " + (b"%16.6f" if args.milliseconds else b"%16.3f")) %
               (agg_colval(k), v.count,
                v.total_ns / (1e6 if args.milliseconds else 1e3)))
    print("")
    if not htab_batch_ops:
        data.clear()

if args.syscall is not None:
    print("Tracing %ssyscall '%s'... Ctrl+C to quit." %
        ("failed " if args.failures else "", args.syscall))
else:
    print("Tracing %ssyscalls, printing top %d... Ctrl+C to quit." %
        ("failed " if args.failures else "", args.top))
exiting = 0 if args.interval else 1
seconds = 0
while True:
    try:
        sleep(args.interval)
        seconds += args.interval
    except KeyboardInterrupt:
        exiting = 1
        signal.signal(signal.SIGINT, signal_ignore)
    if args.duration and seconds >= args.duration:
        exiting = 1

    print_stats()

    if exiting:
        print("Detaching...")
        exit()