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| Dir : //proc/self/root/opt/saltstack/salt/extras-3.10/pyroute2/netlink/rtnl/tcmsg/cls_u32.py |
'''
u32
+++
Filters can take an `action` argument, which affects the packet
behavior when the filter matches. Currently the gact, bpf, and police
action types are supported, and can be attached to the u32 and bpf
filter types::
# An action can be a simple string, which translates to a gact type
action = "drop"
# Or it can be an explicit type (these are equivalent)
action = dict(kind="gact", action="drop")
# There can also be a chain of actions, which depend on the return
# value of the previous action.
action = [
dict(kind="bpf", fd=fd, name=name, action="ok"),
dict(kind="police", rate="10kbit", burst=10240, limit=0),
dict(kind="gact", action="ok"),
]
# Add the action to a u32 match-all filter
ip.tc("add", "htb", eth0, 0x10000, default=0x200000)
ip.tc("add-filter", "u32", eth0,
parent=0x10000,
prio=10,
protocol=protocols.ETH_P_ALL,
target=0x10020,
keys=["0x0/0x0+0"],
action=action)
# Add two more filters: One to send packets with a src address of
# 192.168.0.1/32 into 1:10 and the second to send packets with a
# dst address of 192.168.0.0/24 into 1:20
ip.tc("add-filter", "u32", eth0,
parent=0x10000,
prio=10,
protocol=protocols.ETH_P_IP,
target=0x10010,
keys=["0xc0a80001/0xffffffff+12"])
# 0xc0a800010 = 192.168.0.1
# 0xffffffff = 255.255.255.255 (/32)
# 12 = Source network field bit offset
ip.tc("add-filter", "u32", eth0,
parent=0x10000,
prio=10,
protocol=protocols.ETH_P_IP,
target=0x10020,
keys=["0xc0a80000/0xffffff00+16"])
# 0xc0a80000 = 192.168.0.0
# 0xffffff00 = 255.255.255.0 (/24)
# 16 = Destination network field bit offset
'''
import struct
from socket import htons
from pyroute2.netlink import nla, nlmsg
from pyroute2.netlink.rtnl.tcmsg.act_police import (
get_parameters as ap_parameters,
)
from pyroute2.netlink.rtnl.tcmsg.act_police import nla_plus_police
from pyroute2.netlink.rtnl.tcmsg.common_act import get_tca_action, tca_act_prio
def fix_msg(msg, kwarg):
msg['info'] = htons(kwarg.get('protocol', 0) & 0xFFFF) | (
(kwarg.get('prio', 0) << 16) & 0xFFFF0000
)
def get_parameters(kwarg):
ret = {'attrs': []}
if kwarg.get('rate'):
ret['attrs'].append(['TCA_U32_POLICE', ap_parameters(kwarg)])
elif kwarg.get('action'):
ret['attrs'].append(['TCA_U32_ACT', get_tca_action(kwarg)])
ret['attrs'].append(['TCA_U32_CLASSID', kwarg['target']])
ret['attrs'].append(['TCA_U32_SEL', {'keys': kwarg['keys']}])
return ret
class options(nla, nla_plus_police):
nla_map = (
('TCA_U32_UNSPEC', 'none'),
('TCA_U32_CLASSID', 'uint32'),
('TCA_U32_HASH', 'uint32'),
('TCA_U32_LINK', 'hex'),
('TCA_U32_DIVISOR', 'uint32'),
('TCA_U32_SEL', 'u32_sel'),
('TCA_U32_POLICE', 'police'),
('TCA_U32_ACT', 'tca_act_prio'),
('TCA_U32_INDEV', 'hex'),
('TCA_U32_PCNT', 'u32_pcnt'),
('TCA_U32_MARK', 'u32_mark'),
)
tca_act_prio = tca_act_prio
class u32_sel(nla):
fields = (
('flags', 'B'),
('offshift', 'B'),
('nkeys', 'B'),
('__align', 'x'),
('offmask', '>H'),
('off', 'H'),
('offoff', 'h'),
('hoff', 'h'),
('hmask', '>I'),
)
class u32_key(nlmsg):
header = None
fields = (
('key_mask', '>I'),
('key_val', '>I'),
('key_off', 'i'),
('key_offmask', 'i'),
)
def encode(self):
'''
Key sample::
'keys': ['0x0006/0x00ff+8',
'0x0000/0xffc0+2',
'0x5/0xf+0',
'0x10/0xff+33']
=> 00060000/00ff0000 + 8
05000000/0f00ffc0 + 0
00100000/00ff0000 + 32
'''
def cut_field(key, separator):
'''
split a field from the end of the string
'''
field = '0'
pos = key.find(separator)
new_key = key
if pos > 0:
field = key[pos + 1 :]
new_key = key[:pos]
return (new_key, field)
# 'header' array to pack keys to
header = [(0, 0) for i in range(256)]
keys = []
# iterate keys and pack them to the 'header'
for key in self['keys']:
# TODO tags: filter
(key, nh) = cut_field(key, '@') # FIXME: do not ignore nh
(key, offset) = cut_field(key, '+')
offset = int(offset, 0)
# a little trick: if you provide /00ff+8, that
# really means /ff+9, so we should take it into
# account
(key, mask) = cut_field(key, '/')
if mask[:2] == '0x':
mask = mask[2:]
while True:
if mask[:2] == '00':
offset += 1
mask = mask[2:]
else:
break
mask = '0x' + mask
mask = int(mask, 0)
value = int(key, 0)
bits = 24
if mask == 0 and value == 0:
key = self.u32_key(data=self.data)
key['key_off'] = offset
key['key_mask'] = mask
key['key_val'] = value
keys.append(key)
for bmask in struct.unpack('4B', struct.pack('>I', mask)):
if bmask > 0:
bvalue = (value & (bmask << bits)) >> bits
header[offset] = (bvalue, bmask)
offset += 1
bits -= 8
# recalculate keys from 'header'
key = None
value = 0
mask = 0
for offset in range(256):
(bvalue, bmask) = header[offset]
if bmask > 0 and key is None:
key = self.u32_key(data=self.data)
key['key_off'] = offset
key['key_mask'] = 0
key['key_val'] = 0
bits = 24
if key is not None and bits >= 0:
key['key_mask'] |= bmask << bits
key['key_val'] |= bvalue << bits
bits -= 8
if bits < 0 or offset == 255:
keys.append(key)
key = None
if not keys:
raise ValueError('no keys specified')
self['nkeys'] = len(keys)
# FIXME: do not hardcode flags :)
self['flags'] = 1
nla.encode(self)
offset = self.offset + 20 # 4 bytes header + 16 bytes fields
for key in keys:
key.offset = offset
key.encode()
offset += 16 # keys haven't header
self.length = offset - self.offset
struct.pack_into('H', self.data, self.offset, offset - self.offset)
def decode(self):
nla.decode(self)
offset = self.offset + 16
self['keys'] = []
nkeys = self['nkeys']
while nkeys:
key = self.u32_key(data=self.data, offset=offset)
key.decode()
offset += 16
self['keys'].append(key)
nkeys -= 1
class u32_mark(nla):
fields = (('val', 'I'), ('mask', 'I'), ('success', 'I'))
class u32_pcnt(nla):
fields = (('rcnt', 'Q'), ('rhit', 'Q'), ('kcnts', 'Q'))