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IP fragmentation buffer chains, part 2.

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Change-Id: I8d1072cf9ff9f502302fd906c5590e0f3698dc60
Signed-off-by: Ole Troan <ot@cisco.com>
This commit is contained in:
Ole Troan
2018-08-10 14:39:48 +02:00
committed by Dave Barach
parent 9936831502
commit 7eb9d9608b
2 changed files with 74 additions and 30 deletions
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38
src/vnet/ip/ip_frag.c
View File

@ -128,7 +128,6 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
if (!vlib_buffer_alloc (vm, &to_bi, 1))
{
*error = IP_FRAG_ERROR_MEMORY;
/* XXX: Free already allocated buffers? */
return;
}
vec_add1 (*buffer, to_bi);
@ -152,12 +151,22 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
to_ip4 = vlib_buffer_get_current (to_b) + offset;
to_data = (void *) (to_ip4 + 1);
/* Spin through buffer chain copying data */
// XXX: Make sure we don't overflow source buffer!!!
if (len > left_in_from_buffer)
/* Spin through from buffers filling up the to buffer */
u16 to_ptr = 0;
u16 bytes_to_copy, left_in_to_buffer = len;
while (1)
{
clib_memcpy (to_data, from_data + ptr, left_in_from_buffer);
/* Figure out how many bytes we can safely copy */
bytes_to_copy = left_in_to_buffer <= left_in_from_buffer ?
left_in_to_buffer : left_in_from_buffer;
clib_memcpy (to_data + to_ptr, from_data + ptr, bytes_to_copy);
left_in_to_buffer -= bytes_to_copy;
ptr += bytes_to_copy;
left_in_from_buffer -= bytes_to_copy;
if (left_in_to_buffer == 0)
break;
ASSERT (left_in_from_buffer == 0);
/* Move buffer */
if (!(from_b->flags & VLIB_BUFFER_NEXT_PRESENT))
{
@ -166,18 +175,11 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
}
from_b = vlib_get_buffer (vm, from_b->next_buffer);
from_data = (u8 *) vlib_buffer_get_current (from_b);
clib_memcpy (to_data + left_in_from_buffer, from_data,
len - left_in_from_buffer);
ptr = len - left_in_from_buffer;
left_in_from_buffer =
from_b->current_length - (len - left_in_from_buffer);
}
else
{
clib_memcpy (to_data, from_data + ptr, len);
left_in_from_buffer -= len;
ptr += len;
ptr = 0;
left_in_from_buffer = from_b->current_length;
to_ptr += bytes_to_copy;
}
to_b->current_length = offset + len + sizeof (ip4_header_t);
to_ip4->fragment_id = ip_frag_id;
@ -209,8 +211,6 @@ ip4_frag_do_fragment (vlib_main_t * vm, u32 from_bi, u32 ** buffer,
rem -= len;
fo += len;
}
/* Free original packet chain */
vlib_buffer_free_one (vm, from_bi);
}
void
@ -287,6 +287,8 @@ ip4_frag (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
if (error0 == IP_FRAG_ERROR_NONE)
{
/* Free original buffer chain */
vlib_buffer_free_one (vm, pi0);
frag_sent += vec_len (buffer);
small_packets += (vec_len (buffer) == 1);
}

66
test/test_ipip.py
View File

@ -3,7 +3,7 @@
import unittest
from scapy.layers.inet6 import IPv6, Ether, IP, UDP
from scapy.all import fragment
from scapy.all import fragment, RandShort
from framework import VppTestCase, VppTestRunner
from vpp_ip_route import VppIpRoute, VppRoutePath, DpoProto
from socket import AF_INET, AF_INET6, inet_pton
@ -60,6 +60,18 @@ class TestIPIP(VppTestCase):
def validate(self, rx, expected):
self.assertEqual(rx, expected.__class__(str(expected)))
def generate_frags(self, payload_length, fragment_size):
p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
p_payload = UDP(sport=1234, dport=1234) / self.payload(payload_length)
p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
outer_ip4 = (p_ether / IP(src=self.pg1.remote_ip4,
id=RandShort(),
dst=self.pg0.local_ip4) / p_ip4 / p_payload)
frags = fragment(outer_ip4, fragment_size)
p4_reply = (p_ip4 / p_payload)
p4_reply.ttl -= 1
return frags, p4_reply
def test_ipip4(self):
""" ip{v4,v6} over ip4 test """
p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
@ -142,29 +154,48 @@ class TestIPIP(VppTestCase):
for p in rx:
self.validate(p[1], p6_reply)
#
# Fragmentation / Reassembly and Re-fragmentation
#
rv = self.vapi.ip_reassembly_enable_disable(
sw_if_index=self.pg1.sw_if_index,
enable_ip4=1)
# Decapsulation
p_ether = Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
p_payload = UDP(sport=1234, dport=1234) / self.payload(3123)
p_ip4 = IP(src="1.2.3.4", dst=self.pg0.remote_ip4)
outer_ip4 = (p_ether / IP(src=self.pg1.remote_ip4,
dst=self.pg0.local_ip4) / p_ip4 / p_payload)
frags = fragment(outer_ip4, 1400)
p4_reply = (p_ip4 / p_payload)
p4_reply.ttl -= 1
# Send lots of fragments, verify reassembled packet
frags, p4_reply = self.generate_frags(3131, 1400)
f = []
for i in range(0, 1000):
f.extend(frags)
self.pg1.add_stream(f)
self.pg_enable_capture()
self.pg1.add_stream(frags)
self.pg_start()
rx = self.pg0.get_capture(1)
rx = self.pg0.get_capture(1000)
for p in rx:
self.validate(p[1], p4_reply)
f = []
r = []
for i in range(1, 90):
frags, p4_reply = self.generate_frags(i * 100, 1000)
f.extend(frags)
r.extend(p4_reply)
self.pg_enable_capture()
self.pg1.add_stream(f)
self.pg_start()
rx = self.pg0.get_capture(89)
i = 0
for p in rx:
self.validate(p[1], r[i])
i += 1
# Now try with re-fragmentation
#
# Send fragments to tunnel head-end, for the tunnel head end
# to reassemble and then refragment
#
self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [576, 0, 0, 0])
frags, p4_reply = self.generate_frags(3123, 1200)
self.pg_enable_capture()
self.pg1.add_stream(frags)
self.pg_start()
@ -174,6 +205,17 @@ class TestIPIP(VppTestCase):
p4_reply.id = 256
self.validate(reass_pkt, p4_reply)
self.vapi.sw_interface_set_mtu(self.pg0.sw_if_index, [1600, 0, 0, 0])
frags, p4_reply = self.generate_frags(3123, 1200)
self.pg_enable_capture()
self.pg1.add_stream(frags)
self.pg_start()
rx = self.pg0.get_capture(2)
reass_pkt = reassemble(rx)
p4_reply.ttl -= 1
p4_reply.id = 512
self.validate(reass_pkt, p4_reply)
def test_ipip6(self):
""" ip{v4,v6} over ip6 test """
p_ether = Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)