ligang/vpp
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

VPP-1283: IPv4 PMTU missing MTU value in ICMP4 message.

Browse Source 
Change-Id: I7a4133c59ff45b0744b48e246a049d9f015026fc
Signed-off-by: Ole Troan <ot@cisco.com>
This commit is contained in:
Ole Troan
2018-05-18 11:01:31 +02:00
committed by Florin Coras
parent 2c2feab7d8
commit 8a9c8f1412
5 changed files with 257 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/plugins/igmp/igmp.c
+1 -1
View File
@@ -712,7 +712,7 @@ igmp_timer_process (vlib_main_t * vm, vlib_node_runtime_t * rt,
goto next_timer;
IGMP_DBG ("time: %f", vlib_time_now (vm));
/* timer expired */
if (NULL != timer)
if (NULL != timer && timer->func != NULL)
timer->func (vm, rt, im, timer);
next_timer:
timer = igmp_get_next_timer (im);
src/vnet/ip/icmp4.c
+4 -2
View File
@@ -513,13 +513,15 @@ ip4_icmp_error (vlib_main_t * vm,
b->current_length = 0;
}
}
p0->current_length =
p0->current_length > 576 ? 576 : p0->current_length;
/* Add IP header and ICMPv4 header including a 4 byte data field */
vlib_buffer_advance (p0,
-sizeof (ip4_header_t) -
sizeof (icmp46_header_t) - 4);
p0->current_length =
p0->current_length > 576 ? 576 : p0->current_length;
out_ip0 = vlib_buffer_get_current (p0);
icmp0 = (icmp46_header_t *) & out_ip0[1];
src/vnet/ip/ip4_forward.c
+39 -30
View File
@@ -1963,6 +1963,29 @@ typedef enum
#define IP4_MCAST_ADDR_MASK 0xffff7f00
#endif
always_inline void
ip4_mtu_check (vlib_buffer_t * b, u16 packet_len,
u16 adj_packet_bytes, bool df, u32 * next, u32 * error)
{
if (packet_len > adj_packet_bytes)
{
*error = IP4_ERROR_MTU_EXCEEDED;
if (df)
{
icmp4_error_set_vnet_buffer
(b, ICMP4_destination_unreachable,
ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
adj_packet_bytes);
*next = IP4_REWRITE_NEXT_ICMP_ERROR;
}
else
{
/* Add support for fragmentation here */
*next = IP4_REWRITE_NEXT_DROP;
}
}
}
always_inline uword
ip4_rewrite_inline (vlib_main_t * vm,
vlib_node_runtime_t * node,
@@ -2123,26 +2146,16 @@ ip4_rewrite_inline (vlib_main_t * vm,
vnet_buffer (p1)->ip.save_rewrite_length = rw_len1;
/* Check MTU of outgoing interface. */
if (vlib_buffer_length_in_chain (vm, p0) >
adj0[0].rewrite_header.max_l3_packet_bytes)
{
error0 = IP4_ERROR_MTU_EXCEEDED;
next0 = IP4_REWRITE_NEXT_ICMP_ERROR;
icmp4_error_set_vnet_buffer
(p0, ICMP4_destination_unreachable,
ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
0);
}
if (vlib_buffer_length_in_chain (vm, p1) >
adj1[0].rewrite_header.max_l3_packet_bytes)
{
error1 = IP4_ERROR_MTU_EXCEEDED;
next1 = IP4_REWRITE_NEXT_ICMP_ERROR;
icmp4_error_set_vnet_buffer
(p1, ICMP4_destination_unreachable,
ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
0);
}
ip4_mtu_check (p0, clib_net_to_host_u16 (ip0->length),
adj0[0].rewrite_header.max_l3_packet_bytes,
ip0->flags_and_fragment_offset &
clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
&next0, &error0);
ip4_mtu_check (p1, clib_net_to_host_u16 (ip1->length),
adj1[0].rewrite_header.max_l3_packet_bytes,
ip1->flags_and_fragment_offset &
clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
&next1, &error1);
if (is_mcast)
{
@@ -2326,16 +2339,12 @@ ip4_rewrite_inline (vlib_main_t * vm,
vlib_buffer_length_in_chain (vm, p0) + rw_len0);
/* Check MTU of outgoing interface. */
if (vlib_buffer_length_in_chain (vm, p0) >
adj0[0].rewrite_header.max_l3_packet_bytes)
{
error0 = IP4_ERROR_MTU_EXCEEDED;
next0 = IP4_REWRITE_NEXT_ICMP_ERROR;
icmp4_error_set_vnet_buffer
(p0, ICMP4_destination_unreachable,
ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
0);
}
ip4_mtu_check (p0, clib_net_to_host_u16 (ip0->length),
adj0[0].rewrite_header.max_l3_packet_bytes,
ip0->flags_and_fragment_offset &
clib_host_to_net_u16 (IP4_HEADER_FLAG_DONT_FRAGMENT),
&next0, &error0);
if (is_mcast)
{
error0 = ((adj0[0].rewrite_header.sw_if_index ==
test/test_ip4.py
+1 -1
View File
@@ -1294,7 +1294,7 @@ class TestIPInput(VppTestCase):
dst=self.pg0.local_mac) /
IP(src=self.pg0.remote_ip4,
dst=self.pg1.remote_ip4,
ttl=10) /
ttl=10, flags='DF') /
UDP(sport=1234, dport=1234) /
Raw('\xa5' * 2000))
test/test_mtu.py
+212
View File
@@ -0,0 +1,212 @@
#!/usr/bin/env python
"""IP4 and IP6 MTU functional tests"""
#
# Add tests for:
# - sub interfaces
# - Verify that adjacencies inherit MTU correctly
# - Verify that sub-interfaces inherit MTU correctly
# - Different types of interfaces?
#
import unittest
from scapy.layers.inet6 import IPv6, Ether, IP, UDP, ICMPv6PacketTooBig
from scapy.layers.inet import ICMP
from framework import VppTestCase, VppTestRunner
from vpp_ip_route import VppIpRoute, VppRoutePath, DpoProto
from socket import AF_INET, AF_INET6, inet_pton
import StringIO
""" Test_mtu is a subclass of VPPTestCase classes.
MTU tests.
"""
def reassemble(listoffragments):
buffer = StringIO.StringIO()
first = listoffragments[0]
buffer.seek(20)
for pkt in listoffragments:
# pkt.show2()
buffer.seek(pkt[IP].frag*8)
buffer.write(pkt[IP].payload)
first.len = len(buffer.getvalue()) + 20
first.flags = 0
del(first.chksum)
header = str(first[IP])[:20]
return first[IP].__class__(header + buffer.getvalue())
class TestMTU(VppTestCase):
""" MTU Test Case """
@classmethod
def setUpClass(cls):
super(TestMTU, cls).setUpClass()
cls.create_pg_interfaces(range(2))
cls.interfaces = list(cls.pg_interfaces)
def setUp(cls):
super(TestMTU, cls).setUp()
for i in cls.interfaces:
i.admin_up()
i.config_ip4()
i.config_ip6()
i.disable_ipv6_ra()
i.resolve_arp()
i.resolve_ndp()
def tearDown(self):
super(TestMTU, self).tearDown()
if not self.vpp_dead:
for i in self.pg_interfaces:
i.unconfig_ip4()
i.unconfig_ip6()
i.admin_down()
def validate(self, rx, expected):
self.assertEqual(rx, expected.__class__(str(expected)))
def validate_bytes(self, rx, expected):
self.assertEqual(rx, expected)
def payload(self, len):
return 'x' * len
def get_mtu(self, sw_if_index):
rv = self.vapi.sw_interface_dump()
for i in rv:
if i.sw_if_index == sw_if_index:
return i.link_mtu
return 0
def test_ip4_mtu(self):
""" IP4 MTU test """
#
# TODO: Link MTU is 216 bytes 'off'. Fix when L3 MTU patches committed
#
mtu_offset = 216
p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
p_ip4 = IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4,
flags='DF')
# TODO: Re-enable when MTU fixes are committed
current_mtu = self.get_mtu(self.pg1.sw_if_index)
current_mtu -= mtu_offset
p_payload = UDP(sport=1234, dport=1234) / self.payload(
current_mtu - 20 - 8)
p4 = p_ether / p_ip4 / p_payload
p4_reply = p_ip4 / p_payload
p4_reply.ttl -= 1
rx = self.send_and_expect(self.pg0, p4*11, self.pg1)
for p in rx:
self.validate(p[1], p4_reply)
# MTU
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, 576 + mtu_offset)
self.assertEqual(576, self.get_mtu(self.pg1.sw_if_index) - mtu_offset)
# Should fail. Too large MTU
p_icmp4 = ICMP(type='dest-unreach', code='fragmentation-needed',
nexthopmtu=576, chksum=0x2dbb)
icmp4_reply = (IP(src=self.pg0.local_ip4,
dst=self.pg0.remote_ip4,
ttl=254, len=576, id=0) /
p_icmp4 / p_ip4 / p_payload)
icmp4_reply[1].ttl -= 1
n = icmp4_reply.__class__(str(icmp4_reply))
s = str(icmp4_reply)
icmp4_reply = s[0:576]
rx = self.send_and_expect(self.pg0, p4*11, self.pg0)
for p in rx:
# p.show2()
# n.show2()
self.validate_bytes(str(p[1]), icmp4_reply)
'''
# Now with DF off. Expect fragments.
# First go with 1500 byte packets.
p_payload = UDP(sport=1234, dport=1234) / self.payload(
1500 - 20 - 8)
p4 = p_ether / p_ip4 / p_payload
p4.flags = 0
p4_reply = p_ip4 / p_payload
p4_reply.ttl = 62 # check this
p4_reply.flags = 0
p4_reply.id = 256
self.pg_enable_capture()
self.pg0.add_stream(p4*1)
self.pg_start()
rx = self.pg1.get_capture(3)
print('RX', len(rx))
reass_pkt = reassemble(rx)
self.validate(reass_pkt, p4_reply)
'''
# Now what happens with a 9K frame
'''
p_payload = UDP(sport=1234, dport=1234) / self.payload(
current_mtu - 20 - 8)
p4 = p_ether / p_ip4 / p_payload
p4.flags = 0
p4_reply = p_ip4 / p_payload
p4_reply.ttl = 62 # check this
p4_reply.flags = 0
p4_reply.id = 512
self.pg_enable_capture()
self.pg0.add_stream(p4*1)
self.pg_start()
rx = self.pg1.get_capture(16)
reass_pkt = reassemble(rx)
reass_pkt.show2()
p4_reply.show2()
self.validate(reass_pkt, p4_reply)
'''
# Reset MTU
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, current_mtu)
@unittest.skip("Enable when IPv6 fragmentation is added")
def test_ip6_mtu(self):
""" IP6 MTU test """
p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
p_ip6 = IPv6(src=self.pg0.remote_ip6, dst=self.pg1.remote_ip6)
current_mtu = self.get_mtu(self.pg1.sw_if_index)
p_payload = UDP(sport=1234, dport=1234) / self.payload(
current_mtu - 40 - 8)
p6 = p_ether / p_ip6 / p_payload
p6_reply = p_ip6 / p_payload
p6_reply.hlim -= 1
rx = self.send_and_expect(self.pg0, p6*9, self.pg1)
for p in rx:
self.validate(p[1], p6_reply)
# MTU (only checked on encap)
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, 1280)
self.assertEqual(1280, self.get_mtu(self.pg1.sw_if_index))
# Should fail. Too large MTU
p_icmp6 = ICMPv6PacketTooBig(mtu=1280, cksum=0x4c7a)
icmp6_reply = (IPv6(src=self.pg0.local_ip6,
dst=self.pg0.remote_ip6,
hlim=254, plen=1240) /
p_icmp6 / p_ip6 / p_payload)
icmp6_reply[2].hlim -= 1
n = icmp6_reply.__class__(str(icmp6_reply))
s = str(icmp6_reply)
icmp6_reply = s[0:1280]
rx = self.send_and_expect(self.pg0, p6*9, self.pg0)
for p in rx:
self.validate_bytes(str(p[1]), icmp6_reply)
# Reset MTU
self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, current_mtu)
if __name__ == '__main__':
unittest.main(testRunner=VppTestRunner)