def lookup(self, key):
if not isinstance(key, self.KEY_TYPE):
raise TypeError('key {} is not instance of key_type {}'.format(
repr(key), repr(self.KEY_TYPE)))
key_p = ctypes.cast(ctypes.pointer(key), ctypes.c_char_p)
value = self.VALUE_TYPE()
value_p = ctypes.cast(ctypes.pointer(value), ctypes.c_char_p)
attr = _BpfAttrMapElem(
map_fd=self.fd,
key=key_p,
value_or_next_key=value_p,
flags=0,
)
attr_p = ctypes.pointer(attr)
ret = _syscall.bpf(_MapCmd.LOOKUP_ELEM, attr_p, ctypes.sizeof(attr))
if ret == 0:
return value
eno = _syscall._get_errno()
if eno == errno.ENOENT:
raise KeyError(key)
raise OSError(eno,
'Failed to lookup bpf map: {}'.format(os.strerror(eno)))
def get_next_key(self, last_key):
if not isinstance(last_key, self.KEY_TYPE):
raise TypeError('key {} is not instance of key_type {}'.format(
repr(last_key), repr(self.KEY_TYPE)))
key_p = ctypes.cast(ctypes.pointer(last_key), ctypes.c_char_p)
next_key = self.KEY_TYPE()
next_key_p = ctypes.cast(ctypes.pointer(next_key), ctypes.c_char_p)
attr = _BpfAttrMapElem(
map_fd=self.fd,
key=key_p,
value_or_next_key=next_key_p,
flags=0,
)
attr_p = ctypes.pointer(attr)
ret = _syscall.bpf(_MapCmd.GET_NEXT_KEY, attr_p, ctypes.sizeof(attr))
if ret == 0:
return next_key
eno = _syscall._get_errno()
if eno == errno.ENOENT:
return None
raise OSError(eno,
'Failed to get next key: {}'.format(os.strerror(eno)))
def perf_event_open(attr, pid=-1, cpu=-1, group_fd=-1, flags=0):
_NR_perf_event_open = 298
ret = _syscall.syscall(_NR_perf_event_open, ctypes.byref(attr), pid, cpu,
group_fd, flags)
if ret < 0:
eno = _syscall._get_errno()
raise OSError(eno,
'Failed to open perf event: {}'.format(os.strerror(eno)))
return ret
def _map_create(map_type, key_size, value_size, max_entries):
attr = _BpfAttrMapCreate(map_type=map_type,
key_size=key_size,
value_size=value_size,
max_entries=max_entries,
map_flags=0)
fd = _syscall.bpf(_MapCmd.CREATE, ctypes.pointer(attr),
ctypes.sizeof(attr))
if fd < 0:
eno = _syscall._get_errno()
raise OSError(eno,
'Failed to create bpf map: {}'.format(os.strerror(eno)))
return fd
def _update_elem(fd, key, value):
key_p = ctypes.cast(ctypes.pointer(key), ctypes.c_char_p)
value_p = ctypes.cast(ctypes.pointer(value), ctypes.c_char_p)
attr = _BpfAttrMapElem(
map_fd=fd,
key=key_p,
value_or_next_key=value_p,
flags=0,
)
attr_p = ctypes.pointer(attr)
if _syscall.bpf(_MapCmd.UPDATE_ELEM, attr_p, ctypes.sizeof(attr)) != 0:
eno = _syscall._get_errno()
raise OSError(eno,
'Failed to update bpf map: {}'.format(os.strerror(eno)))
def __init__(self, data_type, cpu, num_pages=9):
self.mm_fd = -1
self.data_type = data_type
self.num_pages = num_pages
try:
attr = pe.PerfEventAttr()
attr.type = pe.PERF_TYPE_SOFTWARE
attr.config = pe.PERF_COUNT_SW_BPF_OUTPUT
attr.sample_type = pe.PERF_SAMPLE_RAW
self.mm_fd = pe.perf_event_open(attr, cpu=cpu)
if self.mm_fd < 0:
eno = _syscall._get_errno()
raise OSError(
eno,
'Failed to create perf event: {}'.format(os.strerror(eno)))
fcntl.ioctl(self.mm_fd, pe.PERF_EVENT_IOC_ENABLE, 0)
self.pagesz = resource.getpagesize()
self.mm = mmap.mmap(self.mm_fd, self.num_pages * self.pagesz)
except Exception:
self.close()
raise
def _load_prog(prog_type, insns_arr, insns_to_info):
log = ctypes.create_string_buffer(2**20)
attr = BpfAttrLoadProg(
prog_type=prog_type,
insn_cnt=len(insns_arr),
insns=ctypes.cast(ctypes.byref(insns_arr), ctypes.c_char_p),
license=ctypes.c_char_p('GPL'.encode()),
log_level=100,
log_size=ctypes.sizeof(log),
log_buf=ctypes.addressof(log),
kern_version=_get_kern_version(),
)
fd = _syscall.bpf(BpfCmd.PROG_LOAD, ctypes.pointer(attr),
ctypes.sizeof(attr))
if fd < 0:
eno = _syscall._get_errno()
last_num = None
for l in log.value.decode().splitlines():
m = re.match('^(\d+): .*', l)
if m is not None:
num = int(m.group(1))
if last_num != num and num in insns_to_info:
last_num = num
if num > 0:
print(file=sys.stderr)
print(insns_to_info[num], file=sys.stderr)
print('', l, file=sys.stderr)
print(file=sys.stderr)
raise OSError(eno,
'Failed to load bpf prog: {}'.format(os.strerror(eno)))
return fd, log.value.decode()
